If you ask any experienced builder, developer, or landscape designer about what needs to be done, first of all, on a newly acquired and not yet developed plot, the answer will be unequivocal: the first thing is drainage, if there is a need for it. And such a need almost always happens. Site drainage is always associated with a very large volume earthworks, so it’s better to do them right away, so as not to disturb the beautiful landscape that any good owners arrange in their possessions.

Of course, the easiest way is to order site drainage services from specialists who will do everything quickly and correctly, using special equipment. However, this will always come at a cost. Perhaps the owners did not plan for these expenses; perhaps they will violate the entire budget planned for the construction and improvement of the site. In this article, we propose to consider the question of how to do the drainage of a site with your own hands, as this will allow you to save a lot of money, and in most cases it is quite possible to do this work yourself.

Why is site drainage needed?

Looking through estimates and price lists related to site drainage, some developers begin to doubt the feasibility of these measures. And the main argument is that before, in principle, no one “bothered” much with this. With this argument for refusing to drain the site, it is worth noting that the quality and comfort of human life has greatly improved. No one wants to live in dampness or in a house with earthen floors. No one wants to see cracks on their home, blind areas and paths that appear after another cold season. All homeowners want to improve their property or, to put it in a modern and fashionable way, to make landscape design. After the rain, no one wants to “knead mud” in stagnant puddles. If this is the case, then drainage is definitely needed. You can do without it only in very rare cases. We will explain in what cases a little later.

Drainage? No, I haven't heard...

Drainage is nothing more than the removal of excess water from the surface of a site or from the depths of the soil. Why is site drainage needed?

First of all, in order to remove excess water from the foundations of buildings and structures. The appearance of water in the area of the base of the foundation can provoke either soil movement - the house will “float”, which is typical for clay soils, or in combination with freezing, frost heaving forces may appear, which will create efforts to “squeeze” the house out of the ground.

Drainage is designed to remove water from basements and basements. No matter how effective the waterproofing is, excess water will still seep through the building structures. Basements in homes without drainage can become damp, which can encourage the growth of mold and other fungi. In addition, precipitation in combination with salts present in the soil very often form aggressive chemical compounds that negatively affect building materials.

Drainage will prevent the septic tank from being “squeezed out” at high levels groundwater. Without drainage, a wastewater treatment system will not last long.
Drainage together with the system and around buildings ensures rapid removal of water, preventing its seepage to the underground parts of buildings.
Drainage prevents the soil from becoming waterlogged. In areas equipped with properly planned and constructed drainage, water will not stagnate.
Waterlogged soil can cause plant roots to rot. Drainage prevents this and creates conditions for the growth of all garden, vegetable and ornamental plants.
With heavy rainfall in areas that have a slope, the fertile layer of soil can be washed away by streams of water. Drainage directs water flows into the drainage system, thereby preventing soil erosion.

Water erosion of fertile soil in the absence of drainage is a serious problem in agriculture

If the site is surrounded by a fence built on a strip foundation, then it can “seal” natural water drainage routes, creating conditions for waterlogging of the soil. Drainage is designed to remove excess water from the perimeter of the site.
Drainage allows you to avoid the formation of puddles on platforms, sidewalks and garden paths.

When drainage is necessary anyway

Let's consider those cases when drainage is needed in any case:

If the site is located on flat terrain, then drainage is required, since if there is a large amount of precipitation or snow melts, the water will simply have nowhere to go. According to the laws of physics, water always goes under the influence of gravity to a lower place, and on a flat landscape it will intensively saturate the soil in a downward direction, which can lead to waterlogging. So, from a drainage point of view, it is beneficial for the site to have a slight slope.
If the site is located in a lowland, then drainage is definitely needed, since water will flow from higher places to those located below.
Areas with a strong slope also require drainage, since quickly flowing water will erode the top fertile layers of the soil. It is better to direct these flows into drainage channels or pipes. Then the bulk of the water will flow through them, preventing the soil layer from being washed away.
If the site is dominated by clay and heavy loamy soils, then after precipitation or melting snow, water will often stagnate on them. Such soils prevent its penetration into the deeper layers. Therefore, drainage is required.
If the groundwater level (GWL) in the area is less than 1 meter, then drainage cannot be avoided.

If the buildings on the site have a deeply buried foundation, then there is a high probability that its base will be in the zone of seasonal rise of groundwater. Therefore, it is necessary to plan drainage at the stage of foundation work.
If a significant part of the site area is covered with artificial surfaces made of concrete, paving stones or paving slabs, and also if there are lawns equipped with an automatic watering system, then drainage is also needed.

From this impressive list, it becomes clear that drainage to one degree or another is necessary in most cases. But before planning and doing it, you need to study the site.

Studying the site for topography, soil type and groundwater level

Each site is individual in terms of topography, soil composition and groundwater level. Even two areas located nearby can be very different from each other, although there will still be a lot in common between them. Modern requirements for construction suggest that the design of a house should begin only after geological and geodetic surveys have been carried out with the preparation of special reports, which will indicate a lot of data, most of which is understandable only to specialists. If we “translate” them into the language of ordinary citizens who do not have an education in the field of geology, hydrogeology and geodesy, then they can be listed as follows:

Topographic survey of the area where it is proposed. The photographs must indicate the cadastral boundaries of the site.
Characteristics of the relief, which should indicate what type of relief is present on the site (undulating or flat). If there are slopes, then their presence and direction are indicated; it is in their direction that the water will flow. Attached is a topographic plan of the site indicating the relief contours.

Characteristics of the soil, what type of soil it is and at what depth it lies on the site. To do this, specialists drill exploration wells in different places on the site, from where they take samples, which are then examined in the laboratory.
Physico-chemical properties of soil. Its ability to be load-bearing for the planned house, as well as as soil in combination with water, will affect concrete, metal and other building materials.
The presence and depth of groundwater, their seasonal fluctuations, taking into account exploration, archival and analytical data. It is also indicated in which soils water can appear and how they will affect the planned building structures.

The degree of soil heaving, the possibility of landslides, subsidence, flooding and swelling.

The result of all these studies should be recommendations on the design and depth of the foundation, the degree of waterproofing, insulation, protection from aggressive chemical compounds, and drainage. It happens that on a seemingly impeccable plot of land, specialists will not allow you to build the house that the owners intended. For example, a house with a basement was planned, and the high ground level forces experts to recommend against doing this, so instead of the originally planned strip foundation with a basement they will recommend a pile floor without underground premises. There is no reason not to trust these studies and specialists, since they have indisputable tools in their hands - measurements, drilling, laboratory experiments, statistics and calculations.

Of course, geological and geodetic surveys are not done for free, they are done at the expense of the developer and are required on a new site. This fact is often the subject of indignation by some owners, but it is worth understanding that this procedure will help save a lot of money during the construction and further operation of the house, as well as while maintaining the site in good condition. Therefore, this seemingly unnecessary and expensive bureaucracy is necessary and very useful.

If a plot of land is purchased with existing buildings that have been in use for at least several years, then you can also order geological and geodetic surveys, but you can do without them and learn about groundwater, its seasonal rise and the unpleasant impact on human life based on other signs. Of course, this will come with a certain amount of risk, but in most cases it works. What you should pay attention to?

First of all, it is communication with former owners plot. It is clear that it is not always in their interests to talk in detail about problems with flooding, but, nevertheless, you can always find out whether any drainage measures have been taken. They will not hide this for anything.
An inspection of the basement can also tell a lot. Regardless of whether cosmetic repairs were made there. If there is a high level of humidity in the premises, it will be immediately felt.

Getting to know your neighbors and interviewing them can be much more informative than communicating with the former owners of the property and house.
If there are wells or boreholes on your property and on your neighbors’ property, then the water level in them will eloquently indicate the groundwater level. Moreover, it is advisable to observe how the level changes in different seasons. Theoretically, the water should rise to its maximum in the spring after the snow has melted. In summer, if there have been dry periods, the groundwater level should drop.
Plants growing on a site can also “tell” a lot to the owner. The presence of plants such as cattail, reed, sedge, horse sorrel, nettle, hemlock, and foxglove indicate that groundwater is at a level of no more than 2.5-3 meters. If even during a drought these plants continue their rapid growth, this once again indicates the proximity of water. If licorice or wormwood grow on the site, then this is evidence that the water is at a safe depth.

Some sources talk about an ancient method of determining the groundwater level that our ancestors used before building a house. To do this, a piece of turf was removed from the area of interest and a shallow hole was dug, a piece of wool was placed at the bottom, an egg was placed on it, and an inverted clay pot and the removed turf were covered on top. After dawn and sunrise, they removed the pot and watched as the dew fell. If the egg and wool are covered in dew, then the water is shallow. If dew has fallen only on the wool, then there is water, but it is at a safe depth. If both the egg and the wool are dry, then the water is very deep. It may seem that this method is akin to quackery or shamanism, but in fact there is an absolutely correct explanation for it, from the point of view of science.
The growth of bright grass in the area even during a drought, as well as the appearance of fog in the evening hours, indicates the proximity of groundwater.
The most the best way Independent determination of groundwater level on the site is the drilling of test wells. To do this, you can use a regular garden auger with extensions. It is better to drill during the highest water rise, that is, in the spring after the snow melts. First of all, wells should be made at the site where a house or existing structure is being built. The well must be drilled to the depth of the foundation plus 50 cm. If water begins to appear in the well immediately or after 1-2 days, this indicates that drainage measures are required.

A beginner's research geologist's kit - a garden auger with an extension cord

If puddles stagnate in the area after rain, this may indicate the proximity of groundwater, as well as the fact that the soil is clayey or heavy loamy, which prevents water from going deeper normally. In this case, drainage is also necessary. It will also be very useful to replace the fertile soil with a lighter one, then there will be no problems with growing most garden and garden plants.

Even a very high groundwater level in the area, although a big problem, is a problem that can be solved with the help of well-calculated and well-executed drainage. Let's give good example– more than half of the territory of Holland lies below sea level, including the capital – the famous Amsterdam. The groundwater level in this country can be several centimeters deep. Those who have been to Holland have noticed that after rain there are puddles there that are not absorbed into the ground, since there is simply nowhere for them to be absorbed. However, in this cozy country, the issue of land drainage is being resolved through a set of measures: dams, dikes, polders, locks, and canals. In Holland there is even a special department, Waterschap, which deals with flood protection. The abundance of windmills in this country does not mean that they grind grain. Most mills are involved in pumping water.

We do not at all encourage you to specifically purchase a plot of land with high level groundwater, on the contrary, this should be avoided by everyone possible ways. And the example of Holland was cited only so that readers could understand that there is a solution to any problem with groundwater. Moreover, in most of the territory former USSR settlements and holiday villages located in areas where groundwater levels are within acceptable limits, and seasonal rises can be dealt with independently.

Types of drainage systems

There are a great variety of drainage systems and their varieties. Moreover, in different sources, their classification systems may differ from each other. We will try to talk about the simplest, from a technical point of view, drainage systems, but at the same time effective, which will help solve the problem of removing excess water from the site. Another argument in favor of simplicity is that the fewer elements any system has and the more time it can operate without human intervention, the more reliable it will be.

Surface drainage

This type of drainage is the simplest, but nevertheless quite effective. It is intended mainly for draining water coming in the form of precipitation or melting snow, as well as for draining excess water in case of any technological processes, for example, when washing cars or garden paths. Surface drainage is done in any case around buildings or other structures, areas, exit points from a garage or yard. Surface drainage comes in two main types:

Point drainage designed to collect and drain water from a specific place. This type of drainage is also called local drainage. The main locations for point drainage are under roof gutters, in pits in front of doors and garage doors, and in locations where irrigation taps are located. In addition to its direct purpose, point drainage can complement another type of surface drainage system.

Storm water inlet is the main element of point surface drainage

Linear drainage needed to remove water from a larger area compared to a single point. It represents a collection trays And channels, mounted with a slope, equipped with various elements: sand traps (sand traps), protective grilles , performing filtering, protective and decorative functions. Trays and channels can be made from a variety of materials. First of all, it is plastic in the form of polyvinyl chloride (PVC), polypropylene (PP), and low-density polyethylene (HDPE). Materials such as concrete or polymer concrete are also widely used. Grates are most often used in plastic, but in areas where increased load is expected, products made of stainless steel or even cast iron can be used. Work on organizing linear drainage requires concrete preparation of the base.

It is obvious that any good surface drainage system almost always combines elements of point and linear. And all of them are combined into a common drainage system, which may also include another subsystem, which we will consider in the next section of our article.

Prices for rainwater inlets

storm drain

Deep drainage

In most cases, surface drainage alone cannot be done. To solve the problem qualitatively, we need another type of drainage - deep, which is a system of special drainage pipes (drains) , laid in those places where it is necessary to lower the groundwater level or divert water from the protected area. Drains are laid with a slope to the side collector, well , artificial or natural reservoir on the site or beyond. Naturally, they are laid below the level of the base of the foundation of the protected building or along the perimeter of the site at a depth of 0.8-1.5 meters to lower the groundwater level to non-critical values. Drains can also be laid in the middle of the site at a certain interval, which is calculated by specialists. Typically, the interval between pipes is 10-20 meters, and they are laid in the form of a herringbone, directed towards the main outlet pipe-collector. It all depends on the groundwater level and its quantity.

When laying drains in trenches, it is imperative to take advantage of all the features of the site’s topography. Water will always flow from a higher place to a lower place, so drains are laid the same way. It is much more difficult if the area is absolutely flat, then the required slope is given to the pipes by adding a certain level to the bottom of the trenches. It is customary to make a slope of 2 cm per 1 meter of pipe for clay and loamy soils and 3 cm per 1 meter for sandy soils. Obviously, with sufficiently long drains, it will be difficult to maintain the required slope on a flat area, since for 10 meters of pipe the level difference will already be 20 or 30 cm, so a necessary measure is to organize several drainage wells that will be able to receive the required volume of water.

It should be noted that even with a smaller slope, water, even at 1 cm per 1 meter or less, will still, obeying the laws of physics, try to go lower, but the flow rate will be less, and this can contribute to silting and clogging of drains. And any owner who has laid sewer or drainage pipes at least once in his life knows that maintaining a very small slope is much more difficult than a large one. Therefore, there is no need to be “embarrassed” in this matter and feel free to set a slope of 3, 4 or even 5 cm per meter of drainage pipe, if the length and planned difference in depth of the trench allows.

Drainage wells are one of the most important components of deep drainage. They can be of three main types:

Rotary wells – arranged where drains make a turn or where several elements are connected. These elements are needed for inspection and cleaning of the drainage system, which must be done periodically. They can be either small in diameter, which will only allow cleaning and rinsing with a stream of water under pressure, but they can also be wide, which provide human access.

Water intake wells – their purpose is absolutely clear from their name. In those areas where there is no possibility of draining water deeper or beyond, it becomes necessary to collect water. This is exactly what these wells are designed for. Previously, they were mainly a structure made of monolithic concrete, concrete rings or brick plastered with cement mortar. Nowadays, plastic containers of various sizes are most often used, which are protected from clogging or silting by geotextiles and crushed stone or gravel. The water collected in the water intake well can be pumped outside the site using special submersible drainage pumps, can be pumped out and transported by tanker trucks, or can settle in a well or pool for further irrigation.

Absorption wells are designed to drain water if the topography of the site does not allow moisture to be removed beyond its boundaries, but the underlying soil layers have good absorption capacity. Such soils include sandy and sandy loam. Such wells are made with large diameters (about 1.5 meters) and depths (at least 2 meters). The well is filled with filter material in the form of sand, sand-gravel mixture, crushed stone, gravel, broken brick or slag. To prevent eroded fertile soil or various blockages from entering from above, the well is also covered with fertile soil. Naturally, the side walls and bottom are protected with sprinkling. Water entering such a well is filtered by its contents and goes deep into sandy or sandy loam soils. The ability of such wells to remove water from the site may be limited, so they are installed when the expected throughput should not exceed 1-1.5 m 3 per day.

Of the drainage systems, the main and most important is deep drainage, since it is it that provides the necessary water regime for both the site and all the buildings located on it. Any mistake in the design and installation of deep drainage can lead to very unpleasant consequences, which can lead to the death of plants, flooding of basements, destruction of house foundations, and uneven drainage of the area. That is why it is recommended not to neglect geological and geodetic research and order a drainage system design from specialists. If it is possible to correct flaws in surface drainage without severely disturbing the landscape of the site, then with deep drainage everything is much more serious, the cost of an error is too high.

Well prices

Overview of components for drainage systems

To independently carry out the drainage of the site and the buildings located on it, you need to find out what components will be required for this. From the widest selection of them, we tried to show the most used ones at present. If previously the market was dominated by Western manufacturers, who, as monopolists, dictated high prices for their products, now a sufficient number of domestic enterprises offer their products, which are in no way inferior in quality.

Surface Drainage Parts

The following parts can be used for point and linear surface drainage:

Name, manufacturer	Purpose and description
Concrete drainage tray 1000140125 mm with stamped galvanized steel grating. Production - Russia.	Designed for surface water drainage. Capacity 4.18 l/sec, can withstand loads of up to 1.5 tons (A15).	880 rub.
Concrete drainage tray with cast iron grate, dimensions 1000140125 mm. Production - Russia.	The purpose and capacity are the same as in the previous example. Capable of supporting loads up to 25 tons (C250).	1480 rub.
Concrete drainage tray with galvanized steel mesh grating, dimensions 1000140125 mm. Production - Russia.	The purpose and capacity are the same. Capable of supporting loads up to 12.5 tons (B125).	1610 rub.
Polymer concrete drainage tray 100014070 mm with a plastic grid. Production - Russia.	The purpose is the same, throughput 1.9 l/sec. Capable of withstanding loads up to 1.5 tons (A15). The material combines the advantages of plastic and concrete.	820 rub.
Polymer concrete drainage tray 100014070 mm with cast iron grate. Production - Russia.	The throughput is the same. Capable of withstanding up to 25 tons of load (C250).	1420 rub.
Polymer concrete drainage tray 100014070 mm with steel mesh grating. Production - Russia.	The throughput is the same. Capable of withstanding up to 12.5 tons of load (B125).	1550 rub.
Plastic drainage tray 100014560 mm with a galvanized stamped grid. Production - Russia.	Made from frost-resistant polypropylene. Flow rate 1.8 l/sec. Capable of withstanding loads up to 1.5 tons (A15).	760 rub.
Plastic drainage tray 100014560 mm with cast iron grate. Production - Russia.	Flow rate 1.8 l/sec. Capable of supporting loads up to 25 tons (C250).	1360 rub.
Complete plastic storm water inlet (siphon-partitions 2 pcs., waste basket – 1 pc.). Size 300300300 mm. With plastic grille. Production - Russia.	Designed for point drainage of water flowing from the roof through a drainpipe, and can also be used to collect water under yard and garden watering taps. Can be connected to shaped parts with diameters of 75, 110, 160 mm. Removable basket allows for quick cleaning. Withstands loads up to 1.5 tons (A15).	For a set including siphon partitions, a waste collection basket and a plastic grill - 1000 rubles.
Complete plastic storm water inlet (siphon-partitions 2 pcs., waste basket – 1 pc.). Size 300300300 mm. With cast iron grate “Snowflake”. Production - Russia.	The purpose is similar to the previous one. Withstands loads up to 25 tons (C250).	For a set including siphon partitions, a waste collection basket and a cast iron grate - 1,550 rubles.
The sand trap is plastic with a galvanized steel grid. Dimensions 500116320 mm.	Designed to collect dirt and debris in surface linear drainage systems. It is installed at the end of a line of gutters (trays) and is subsequently connected to the pipes of the storm sewer system with a diameter of 110 mm. Capable of withstanding loads up to 1.5 tons (A15).	For a set including grilles 975 rubles.

In the table we intentionally showed trays and storm water inlets Russian production, made from materials different from each other and having different configurations. It is also worth noting that the trays have different widths and depths and, accordingly, their throughput is also not the same. There are a lot of options for the materials from which they are made and sizes; there is no need to list them all, since it depends on many factors: the required throughput, the expected load on the ground, the specific implementation scheme of the drainage system. That is why it is best to entrust drainage system calculations to specialists who will calculate the required size, quantity, and select components.

There was absolutely no need to talk about possible components for drainage trays, rain inlets and sand traps in the table, since in each individual case they will be different. When purchasing, if there is a system design, the seller will always suggest the ones you need. They can be end caps for trays, fastenings for gratings, various corner and transition elements, reinforcing profiles and others.

A few words should be said about sand traps and storm water inlets. If surface linear drainage around the house is implemented with rainwater inlets in the corners (and this is usually done), then sand traps will not be required. Stormwater inlets with siphon partitions and waste baskets perform their role perfectly. If the linear drainage does not have storm inlets and goes into a sewer drainage pipe, then a sand trap is required. That is, any transition from drainage trays to pipes must be done either using a storm inlet or a sand trap. Only this way and no other way! This is done to ensure that sand and various heavy debris do not get into the pipes, as this can lead to their rapid wear, and over time both they and the drainage wells will become clogged. It is difficult to disagree with the fact that it is easier to periodically remove and wash the baskets while on the surface than to go down into the wells.

Surface drainage also includes wells and pipes, but they will be discussed in the next section, since, in principle, they are the same for both types of systems.

Details for deep drainage

Deep drainage is more complex engineering system, requiring more parts. In the table we present only the main ones, since all their diversity will take up a lot of space and attention of our readers. If you wish, it will not be difficult to find catalogs of manufacturers of these systems and select the necessary parts and components for them.

Name and manufacturer	Purpose and description	Approximate price (as of October 2016)
Drainage pipe with a diameter of 63 mm made of HDPE, corrugated, single-walled, in a geotextile filter. Manufacturer: Sibur, Russia.	Designed to remove excess moisture from foundations and areas. Wrapped with geotextile to prevent clogging of pores with soil and sand, which prevents clogging and silting. They have full (circular) perforation. Made from low-density polyethylene (HDPE). Hardness class SN-4. Laying depth up to 4 m.	For 1 m.p. 48 rub.
Drainage pipe with a diameter of 110 mm made of HDPE, corrugated, single-walled, in a geotextile filter. Manufacturer: Sibur, Russia.	similar to above	For 1 m.p. 60 rub.
Drainage pipe with a diameter of 160 mm made of HDPE, corrugated, single-walled, in a geotextile filter. Manufacturer: Sibur, Russia.	similar to above	For 1 m.p. 115 rub.
Drainage pipe with a diameter of 200 mm made of HDPE, corrugated, single-walled, in a geotextile filter. Manufacturer: Sibur, Russia.	similar to above	For 1 m.p. 190 rub.
Single-wall corrugated HDPE drainage pipes with a coconut coir filter with diameters of 90, 110, 160, 200 mm. Country of origin: Russia.	Designed to remove excess moisture from foundations and areas on clay and peaty soils. Coconut coir has increased reclamation properties and strength compared to geotextiles. They have circular perforation. Hardness class SN-4. Laying depth up to 4 m.	219, 310, 744, 1074 rub. for 1 m.p. (depending on diameter).
Double-layer drainage pipes with a Typar SF-27 geotextile filter. The outer layer of HDPE is corrugated, the inner layer of LDPE is smooth. Diameters 110, 160, 200 mm. Country of origin: Russia.	Designed to remove excess moisture from foundations and areas on all types of soils. They have full (circular) perforation. The outer layer protects from mechanical influences, and the inner layer allows, due to its smooth surface, to remove a larger amount of water. The two-layer design has a stiffness class of SN-6 and allows pipes to be laid at a depth of up to 6 meters.	160, 240, 385 rub. for 1 m.p. (depending on diameter).
PVC pipes for sewerage are smooth with a socket with an outer diameter of 110, 125, 160, 200 mm, length 1061, 1072, 1086, 1106 mm, respectively. Country of origin: Russia.	Designed for organizing an external sewer system, as well as storm drainage or drainage systems. They have a hardness class of SN-4, which allows them to be laid at a depth of up to 4 meters.	180, 305, 270, 490 rub. for pipes: 1101061 mm, 1251072 mm, 1601086 mm, 2001106 mm, respectively.
Well shafts with a diameter of 340, 460, 695, 923 mm made of HDPE. Country of origin: Russia.	Designed to create drainage wells (rotary, water intake, absorption). They have a two-layer construction. Ring stiffness SN-4. Maximum length – 6 meters.	950, 1650, 3700, 7400 rub. for wells with diameters of 340, 460, 695, 923 mm, respectively.
Bottom-plug for wells with diameters of 340, 460, 695, 923 mm made of HDPE. Country of origin: Russia.	Designed for creating drainage wells: rotary or water intake.	940, 1560, 4140, 7100 for wells with diameters of 340, 460, 695, 923 mm, respectively.
Insertion into the well on site with diameters of 110, 160, 200 mm. Country of origin: Russia.	Designed for insertion into a well at any level of sewer or drainage pipes of appropriate diameters.	350, 750, 2750 rub. for inserts with diameters of 110, 160, 200 mm, respectively.
Polymer concrete hatch for drainage wells with a diameter of 340 mm. Country of origin: Russia.		500 rub.
Polymer concrete hatch for drainage wells with a diameter of 460 mm. Country of origin: Russia.	Designed for installation on drainage wells. Withstands loads of up to 1.5 tons.	850 rub.
Polyester geotextile with a density of 100 g/m². Country of origin: Russia.	Used to create drainage systems. Not susceptible to rotting, mold, rodents and insects. Roll length from 1 to 6 m.	20 rub. for 1 m².

From the presented table it can be seen that the cost of even Russian-made parts for drainage systems can hardly be called cheap. But the effect of their use will please the owners of the site for at least 50 years. This is the service life that the manufacturer claims. Considering that the material used to make drainage parts is absolutely inert with respect to all substances found in nature, we can assume that the service life will be much longer than stated.

We deliberately did not include previously widely used asbestos-cement or ceramic pipes in the table, since apart from high prices and difficulties in transportation and installation, they will not bring anything. This is yesterday's century.

To create drainage systems, there are many more components from various manufacturers. These include tray parts, which can be throughput, connecting, prefabricated and dead-end. They are designed to connect drainage pipes of various diameters to wells. They provide drainage pipe connections at different angles.

Despite all the obvious advantages of tray parts with pipe sockets, their price is very high. For example, the part shown in the figure above costs 7 thousand rubles. Therefore, in most cases, the taps into the well indicated in the table are used. Another advantage of cut-ins is that they can be made at any level and at any angle to each other.

In addition to those parts for drainage systems that are indicated in the table, there are many others that are selected according to calculations and during installation on site. These may include various cuffs and O-rings, couplings, tees and crosses, check valves for drainage and sewer pipes, eccentric transitions and necks, bends, plugs and much more. Their correct selection should be done, first of all, during design, and then adjustments should be made during installation.

Video: How to choose a drainage pipe

Video: Drainage wells

If readers find articles on drainage on the Internet that say that it is easy to make drainage with your own hands, then we advise you to immediately close this article without reading it. Making drainage with your own hands is not an easy task. But the main thing is that this is possible if you do everything consistently and correctly.

Design of the site drainage system

The drainage system is a complex engineering object that requires appropriate treatment. Therefore, we recommend that our readers order site drainage design from professionals who will take into account absolutely everything: the topography of the site, existing (or planned) buildings, soil composition, groundwater depth, and other factors. After design, the customer will have a set of documents on hand, which includes:

Plan of the site with its relief.
A diagram for laying pipes for wall or ring drainage, indicating the cross-section and type of pipes, depth, required slopes, and location of wells.
A drainage diagram of the site also indicating the depth of the trenches, types of pipes, slopes, distance between adjacent drains, location of rotary or water intake wells.

It will be difficult to make a detailed design of a drainage system on your own without knowledge and experience. This is why you should turn to professionals

A diagram of surface point and linear drainage indicating the size of trays, sand traps, storm water inlets, sewer pipes used, and the location of water intake wells.
Transverse dimensions of trenches for wall and deep drainage, indicating the depth, material and thickness of the filling, and the type of geotextile used.
Calculation of necessary components and materials.
Explanatory note for the project, describing the entire drainage system and technology for performing the work.

The design of a site drainage system costs significantly less than an architectural design, so we once again strongly advise you to contact specialists. This minimizes the likelihood of errors when installing drainage yourself.

Home wall drainage equipment

To protect the foundations of houses from the effects of groundwater, so-called wall drainage is made, which is located around the entire house from the outside at some distance from the base of the foundation. usually it is 0.3-0.5 m, but in any case no more than 1 meter. Wall drainage is done at the stage of building a house along with measures for insulation and waterproofing of the foundation. When is this type of drainage necessary anyway?

Prices for drainage systems

When the house has a ground floor.

When the buried parts of the foundation are located no more than 0.5 meters above the groundwater level.
When a house is built on clay or loamy soils.

All modern projects houses almost always provide wall drainage. The only exceptions can be those cases when the foundation is laid on sandy soils that do not freeze more than 80 cm.

A typical wall drainage design is shown in the figure.

At some distance from the base of the foundation, approximately 30 cm below its level, a leveling layer of sand of 10 cm is made, on which a geotextile membrane with a density of at least 150 g/m² is laid, on which is poured a layer of crushed stone of a fraction of 20-40 mm with a thickness of at least 10 cm. Instead of crushed stone, washed gravel can be used. It is better to use granite crushed stone, but not limestone, since the latter tends to be gradually eroded by water. A drainage pipe wrapped in geotextile is laid on a crushed stone bed. The pipes are given the required slope - at least 2 cm per 1 linear meter of pipe.

Inspection and inspection wells must be made at the places where the pipe turns. The rules allow them to be done every other turn, but practice suggests that it is better not to skimp on this and to place them at every turn. The slope of the pipes is made in one direction (in the figure from point K1, through points K2 and K3, to point K4). In this case, it is necessary to take into account the terrain. It is assumed that point K1 is located at the very high place, and K4 is at the lowest.

Drains are inserted into wells not from the very base, but with an indentation of at least 20 cm from the bottom. Then the small debris or silt that gets in will not linger in the pipes, but will settle in the well. Later, when inspecting the system, you can wash away the silty bottom with a strong stream of water, which will carry away everything unnecessary. If the soil in the area where the wells are located has good absorption capacity, then the bottom is not made. In all other cases, it is better to equip wells with a bottom.

A layer of crushed stone or washed gravel with a thickness of at least 20 cm is again poured over the drains, and then it is wrapped with a previously laid geotextile membrane. On top of such a “wrapped” structure from a drainage pipe and crushed stone, a backfill of sand is made, and on top, after compacting it, a blind area of the building is already organized, which is also intended to be used, but in a system of surface linear drainage. Even if atmospheric water enters from the outside of the foundation, after passing through the sand, it will enter the drains and through them will eventually flow into the main collector well, which can be equipped with a pump. If the terrain of the site allows, then an overflow without a pump is made from the collector well, removing water beyond the boundaries into a drainage ditch, an artificial or natural reservoir or a storm sewer system. Under no circumstances should drainage be connected to a regular sewer system.

If groundwater begins to “back up” from below, then it first of all saturates the sand preparation and crushed stone in which the drains are located. The speed of water movement through the drains is higher than in the ground, so the water is quickly removed and drained into a collector well, which is laid lower than the drains. It turns out that inside a closed loop of drainage pipes, water simply cannot rise above the level of the drains, which means both the base of the foundation and the floor in the basement will be dry.

This wall drainage scheme is very often used and works very effectively. But it has a significant drawback. This is backfilling the entire cavity between the foundation and the edge of the pit with sand. Considering the considerable volume of the sinus, you will have to pay a tidy sum for this filling. But there is a beautiful way out of this situation. To avoid backfilling with sand, you can use a special profiled geomembrane, which is a canvas made of HDPE or LDPE with various additives, having a relief surface in the form of small truncated cones. When the underground part of the foundation is covered with such a membrane, it performs two main functions.

The geomembrane itself is an excellent waterproofer. It prevents moisture from penetrating the walls of the underground foundation structure.
The textured surface of the membrane ensures that the water that appears on it flows freely downwards, where it will be “caught” by the installed drains.

The design of wall drainage using a geomembrane is shown in the following figure.

On the outer wall of the foundation, after installation and insulation (if necessary), a geomembrane is glued or mechanically fastened with the relief part (pimples) facing outwards. A geotextile fabric with a density of 150-200 g/m² is fixed on top of it, which will prevent clogging of the relief part of the geomembrane with soil particles. Further organization of drainage proceeds as usual: a drain lined with crushed stone and wrapped in geotextile is placed on a layer of sand. Only the sinuses are filled not with sand or crushed stone, but with ordinary soil taken out when digging a pit or with clay, which is significantly cheaper.

The drainage of water “propping up” the foundation from below proceeds as in the previous case. But water that enters the wall from the outside through moistened soil or penetrates into the gap between the foundation and the soil will follow the path of least resistance: seep through geotextiles, flow freely along the relief surface of the geomembrane, pass through crushed stone and end up in the drain. Foundations protected in this way will not be threatened for at least 30-50 years. IN ground floors such houses will always be dry.

Let's consider the main stages of creating a wall drainage system for a house.

Image	Description of actions
	After measures have been taken to construct the foundation, its initial coating, and then roll waterproofing and insulation, a geomembrane is glued to the outer wall of the foundation, including its base, using a special mastic that does not corrode polystyrene foam, with the relief part facing out. The upper part of the membrane should protrude beyond the level of the future backfill by at least 20 cm, and the lower part should reach the very bottom of the foundation, including the base.
	The joints of most geomembranes have a special lock that is “locked” by overlapping one sheet over the other and then tapping it with a rubber mallet.
	A geotextile fabric with a density of 150-200 g/m² is attached on top of the geomembrane. It is better to use thermally bonded geotextiles rather than needle-punched ones, since they are less susceptible to clogging. Disc-shaped dowels are used for fixation. The dowel fastening spacing is no more than 1 m horizontally and no more than 2 m vertically. The overlap of adjacent geotextile sheets on each other is at least 10-15 cm. Disc-shaped dowels should be located at the joint.
	At the top of the geomembrane and geotextile, it is recommended to use a special mounting strip, which will press both layers to the foundation structure.
	The bottom of the pit from the outside of the foundation is cleaned to the required level. The level can be controlled by a theodolite with a measuring bar, a laser level and a handy wooden bar with marked marks, tensioned and adjusted using a hydraulic level with a tensioned cord. You can also “beat off” a horizontal line on the wall and measure the depth using a tape measure.
	Washed sand is poured onto the bottom in a layer of at least 10 cm, which is moistened with water and compacted mechanically or manually until there are practically no traces left when walking.
	Inspection wells are installed in the designated locations. To do this, it is enough to use shafts with a diameter of 340 or 460 mm. Having measured the required length, they can be cut with a regular hacksaw, or a jigsaw, or a reciprocating saw. Initially, the wells must be cut 20-30 cm longer than the estimated length, and later, when designing the landscape, they must be adjusted to fit it.
	Bottoms are installed on wells. To do this, in single-layer wells (for example, Wavin), a rubber cuff is placed in the edge of the body, then it is lubricated with a soap solution and the bottom is installed. It should go in with force.
	In Russian-made two-layer wells, before installing the cuff, it is necessary to cut out a strip of the inner layer with a knife, and then do the same as in the previous case.
	The wells are installed in their intended places. The areas for their installation are compacted and leveled. On their side surfaces, marks are made for the entrance and exit of the drain centers (taking into account slopes of 2 cm per 1 linear meter of pipe). We remind you that the inlets and outlets of the drains must be at least 20 cm from the bottom.
	To make it easier to insert couplings, it is better to place the wells horizontally and make holes using a crown and a centering drill corresponding to the coupling. If you don't have a crown, you can make holes with a jigsaw, but this requires certain skills.
	After this, the edges are cleared of burrs with a knife or brush.
	The outer rubber sleeve of the coupling is placed inside the hole. It should go inside the well and stay outside equally (about 2 cm each).
	The inner surface of the rubber cuff of the coupling is lubricated with a soap solution, and then the plastic part is inserted until it stops. The junction of the rubber part of the coupling to the well can be coated with waterproof sealant.
	The wells are installed in their places and aligned vertically. Geotextiles are spread on a sand bed. Granite crushed stone of a fraction of 5-20 mm or washed gravel is poured onto it in a layer of at least 10 cm. The required slopes of the drainage pipes are taken into account. The crushed stone is leveled and compacted.
	Perforated drainage pipes of the required size are measured and cut. The pipes are inserted into couplings cut into the wells after lubricating the cuff with soapy water. Their bias is checked.
	A layer of crushed stone or gravel of at least 20 cm is poured on top of the drains. Then the edges of the geotextile fabric are wrapped on top of each other and sprinkled with a 20 cm layer of sand on top.
	In the designated location, a pit is dug for the collector well of the drainage system. Its level, naturally, must be below the lowest drain in order to receive water from the wall drainage. A trench is dug to this pit from the lower level inspection and inspection well for laying a sewer pipe.
	Shafts with diameters of 460, 695 and even 930 mm can be used as a collector well. A prefabricated well made of reinforced concrete rings can also be installed. Inserting a sewer pipe into a receiving collector well is done in exactly the same way as drains.
	The sewer pipe leading from the lower level of the wall drainage well to the collector well is laid on a 10 cm sand cushion and sprinkled with sand of at least 10 cm thickness on top. After compacting the sand, the trench is filled with soil.
	The system is checked for functionality. To do this, water is poured into the highest level well. After filling the bottom, water should begin to flow through the drains into other wells and, after filling their bottoms, eventually flow into the collector well. There should be no reverse current.
	After checking the functionality, the sinuses between the edge of the pit are filled with soil. It is preferable to use quarry clay for this, which will create a waterproof castle around the foundation.
	The wells are covered with lids to prevent clogging. Final trimming and installation of covers should be done in conjunction with landscaping work.

A collector drainage well can be equipped with a check valve, which, even if it overflows, does not allow water to flow back into the drains. And also in the well there can be an automatic one. When the groundwater level increases to critical values, water will collect in the well. The pump is configured so that when a certain level in the well is exceeded, it will turn on and pump water outside the site or into other containers or reservoirs. Thus, the groundwater level in the foundation area will always be lower than the laid drains.

It happens that one collector well is used for wall and surface drainage systems. Experts do not recommend doing this, since during intense snow melting or heavy rains a lot of snow will accumulate in a short time. a large number of water, which will only interfere with inspecting the water supply system in the area of the foundation. It is better to collect water from precipitation and melted snow in separate containers and use it for irrigation. If storm wells overflow, water from them can be pumped to another location in the same way using a drainage pump.

Video: Wall drainage at home

House ring drainage equipment

Ring drainage, unlike wall drainage, is not located close to the foundation structure, but at some distance from it: from 2 to 10 meters or more meters. In what cases is ring drainage suitable?

If the house has already been built and any intervention in the foundation structure is undesirable.
If the house does not have a basement.
If a house or group of buildings is built on sandy or sandy loam soils that have good permeability to water.
If other types of drainage fail to cope with the seasonal rise of groundwater.

Regardless of the fact that ring drainage is much simpler in practical implementation, the attitude towards it should be more serious than towards wall drainage. Why?

A very important characteristic is the depth of the drains. In any case, the depth of the foundation must be greater than the depth of the base of the foundation or the level of the basement floor.
The distance from the foundation to the drain is also an important characteristic. The sandier the soil, the greater the distance should be. And vice versa - the more clay the soil, the closer the drains can be located to the foundation.
When calculating the ring foundation, the groundwater level, its seasonal fluctuations and the direction of its inflow are also taken into account.

Based on all of the above, we can safely say that it is better to entrust the calculation of ring drainage to specialists. It would seem that the closer the drain is to the house and the deeper it is laid, the better it will be for the structure being protected. It turns out not! Any drainage changes the hydrogeological situation in the area of the foundation, which is not always good. The task of drainage is not to completely dry the area, but to lower the groundwater level to such values that will not interfere with human and plant life. Drainage is a kind of agreement with the forces of Mother Nature, and not an attempt to “rewrite” existing laws.

One of the options for constructing a ring drainage system is shown in the figure.

It can be seen that around the house, already outside the blind area, a trench has been dug to such a depth that the upper part of the drainage pipe lies 30-50 cm below the bottom point of the foundation. The trench is lined with geotextile and the pipe itself is also encased in it. The minimum underlying layer of crushed stone must be at least 10 cm. The minimum slope of drains with a diameter of 110-200 mm is 2 cm per 1 linear meter of pipe. The picture shows that the entire trench is filled with rubble. This is completely acceptable and does not contradict anything other than common sense, in terms of unnecessary spending.

The diagram shows that the inspection and control wells are installed through one turn, which is quite acceptable if the drainage pipe is laid in one piece, without any fittings. But it’s still better to do them at every turn. This will make servicing the drainage system much easier over time.

A ring drainage system can “get along” perfectly with a surface point and linear drainage system. In one trench drains can be laid at the lower level, and next to them or on top in a layer of sand sewer pipes can be laid leading from trays and storm water inlets to a well for collecting rain and melt water. If the path of both leads to the same collector drainage well, then this is generally wonderful; the amount of excavation work is reduced significantly. Although, let us remind you that we recommended collecting these waters separately. They can be collected together only in one case - if all the water from precipitation and extracted from the ground is removed (naturally or forcibly) from the site into a collective storm sewer system, drainage ditch or reservoir.

When organizing ring drainage, a trench is first dug to the calculated depth. The width of the trench in the area of its bottom must be at least 40 cm; the bottom of the trench is immediately given a certain slope, the control of which is most convenient with a theodolite, and in its absence, a cord stretched horizontally and a measuring rod from available means will help.

Washed sand is poured onto the bottom in a layer of at least 10 cm, which is carefully compacted. Obviously, it is impossible to do this in a narrow trench using a mechanized method, so a manual tamper is used.

Installing wells, inserting couplings, adding crushed granite or gravel, laying and connecting drains is done in exactly the same way as when organizing wall drainage, so there is no point in repeating it. The difference is that with ring drainage, it is better to fill the trench after crushed stone and geotextiles not with soil, but with sand. Only the top fertile soil layer of approximately 10-15 cm is poured. Then, when landscaping the site, the places where drains are laid are taken into account and trees or shrubs with a strong root system are not planted in these places.

Video: Drainage around the house

Surface point and linear drainage equipment

As in all cases, a surface drainage system can only be successfully installed if there is a project or at least a self-made plan. On this plan, it is necessary to take into account everything - from water intake points to the container where rain and melt water will be drained. In this case, it is necessary to take into account the slopes of pipelines and trays, the direction of movement along the trays.

A surface drainage system can be installed on an existing blind area, paths made of paving slabs or paving stones. It is possible that some of their parts will have to be interfered with, but this still will not require complete dismantling. Let's consider an example of installing a surface drainage system using the example of polymer concrete trays and sand traps (sand traps) and sewer pipes.

To carry out the work you will need a very simple set of tools:

Scoop and bayonet shovels;
Construction bubble level from 60 cm long;
Bench hammer;
Rubber hammer for laying tiles or paving stones;
Construction marking cord and a set of wooden stakes or pieces of reinforcement;
Trowel and spatulas;
Roulette;
Construction knife;
Chisel;
Angle grinder (grinder) with discs of at least 230 mm for stone and metal;
Container for preparing solutions.

We present the further process in the form of a table.

Image	Process description
	Considering the surface drainage plan or project, it is necessary to determine the water discharge points, that is, those places where water collected from the surface will go into the sewer pipeline leading to the drainage well. The depth of this pipeline must be laid below the depth of soil freezing, which for most populated climatic zones of Russia is 60-80 cm. It is in our interests to minimize the number of discharge points, but to ensure the required drainage capacity.
	Discharge of water into the pipeline must be done either through sand traps or through storm water inlets to ensure filtering of debris and sand. First of all, it is necessary to provide for their connection using standard shaped elements of external sewerage to the pipeline and try on these elements at the installation site.
	It is better to provide for the connection of rainwater inlets located under drainpipes in advance, even at the stage of arranging wall drainage, so that when the snow melts during thaws and the off-season, the water flowing from the roofs immediately enters the underground pipeline and does not freeze in the trays, blind areas and paths.
	If it is not possible to install sand traps, then you can connect the sewer pipeline directly to the trays. For this purpose, polymer concrete trays have special technological holes that allow connecting a vertical pipeline.
	Some manufacturers have special baskets attached to the vertical water discharge, which protect the drainage system from clogging.
	Most plastic trays, in addition to vertical connections, can also have lateral connections. But this should be done only when there is confidence in the purity of the discharged water, since it is much more difficult to clean drainage wells and catchment containers than baskets.
	To install surface drainage elements, you first need to select soil to the required depth and width. To do this, with an existing lawn, the turf is cut to the required width, which is defined as the width of the element being installed plus 20 cm - 10 cm on each side. It may be necessary to dismantle curbs and outer rows of paving slabs or paving stones.
	In depth for installing drainage elements, it is necessary to select soil equal to the depth of the element plus 20 cm. Of these, 10 cm for sand or crushed stone preparation, and 10 cm for a concrete base. The soil is removed, the base is cleaned and compacted, and then a backfill is made of crushed stone of a fraction of 5-20 mm. Then the pegs are driven in and the cord is pulled, which will determine the level of the trays to be installed.
	Elements of surface drainage are tried on at the installation site. In this case, the direction of water flow, which is usually indicated on the side surface of the trays, should be taken into account.
	Holes are made in the drainage elements for connecting sewer pipes. In plastic trays this is done with a knife, and in polymer concrete trays with a chisel and hammer.
	When fitting parts, it may be necessary to cut off part of the tray. Plastic ones are easily cut with a hacksaw, and polymer concrete ones with a grinder. Galvanized metal grates are cut with metal shears, and cast iron grates are cut with a grinder.
	End caps are installed on the last trays using a special adhesive-sealant.
	To install surface drainage elements, it is best to use ready-made dry mixtures of sand concrete M-300, which are available from many manufacturers. A solution is prepared in a suitable container, which should be dense in consistency. It is better to install from the discharge points – sand traps. Concrete is laid on the prepared base.
	Then it is leveled with a trowel and a sand trap is installed on this pad.
	Then it is aligned along the previously stretched cord. If necessary, press the tray into place using a rubber hammer.
	Check the correct installation using the cord and level.
	Trays and sand traps are positioned so that when the grate is installed, its plane is 3-5 mm below the surface level. Then the water will flow freely into the trays, and the grilles will not be damaged by car wheels.
	The leveled sand trap is immediately fixed on the sides with concrete mixture. A so-called concrete heel is formed.
	Similarly, drainage trays are installed on the concrete base.
	They are also aligned both by cord and level.
	After installation, the joints are sealed with a special sealant, which is always offered when purchasing trays.
	Experienced installers can apply sealant before installing the trays, applying it to the ends before installation.
	When installing plastic trays into concrete, they may become deformed. Therefore, it is better to install them with installed grilles, which, to avoid contamination, are best wrapped in plastic film.
	If the surface is flat and has no slopes, then ensuring the required slope of the trays will be problematic. The way out of this situation is to install a cascade of trays of the same width but different depths.
	After installing all the surface drainage elements, a concrete heel is formed, and then paving stones or paving slabs are installed in place, if they were dismantled. The surface of the paving stones should be 3-5 mm higher than the grid of the drainage tray.
	An expansion joint must be made between the paving stones and the trays. Instead of the recommended rubber cords, you can use a strip of roofing felt folded in half and sealant.
	After the concrete has set, after 2-3 days you can backfill the excavated soil.
	After compacting the soil, the previously removed layer of turf is laid on top. It needs to be laid 5-7 cm higher than the rest of the lawn surface, as over time it will compact and settle.
	After flushing the entire surface drainage system and checking its performance, the trays, rainwater inlets and sand traps are closed with grates. It is possible to subject elements to vertical load only after 7-10 days.

When operating a surface drainage system, it is necessary to periodically clean storm water inlets and sand traps. If necessary, you can remove the protective grilles and wash the trays themselves with a strong stream of water. Water collected after rains or melting snow is most suitable for later use for watering the garden, vegetable garden or lawns. Groundwater collected by a deep drainage system may have a different chemical composition and cannot always be used for the same purposes. Therefore, we once again remind and advise our readers to collect groundwater and atmospheric water separately.

Video: Installation of a drainage system

Equipment for deep drainage of the site

We have already described in what cases deep drainage of a site is needed and found out that it is almost always needed in order to forever forget about the problems of stagnant puddles, constant dirt or the death of various plants that cannot tolerate waterlogged soils. The difficulty of equipping deep drainage is that if the site has already been landscaped, trees and shrubs have been planted, and there is a well-groomed lawn, then this order will have to be disrupted at least partially. Therefore, we recommend immediately organizing a deep drainage system on newly acquired plots for construction. As in all other cases, the design of such a drainage system must be ordered from specialists. Independent incorrect calculation and execution of the drainage system can lead to the fact that waterlogged areas on the site will be adjacent to dry ones.

In areas with pronounced topography, a drainage system can become a beautiful part of the landscape. To do this, an open canal or network of canals is organized through which water can freely flow beyond the site. Storm drains from the roof can also be directed into the same channels. But readers will certainly agree with the authors that the presence of a large number of channels will bring more inconvenience than benefits from their contemplation. That is why closed-type deep drainage is most often equipped. Opponents of deep drainage may argue that such systems can lead to excessive drainage of fertile soil, which will negatively affect plants. However, any fertile soils have a very good and useful property - they retain exactly as much water in their thickness as is necessary, and plants growing on the soils take from it exactly as much water as is necessary for their root system.

The main guiding document for organizing a drainage system is a graphic plan of the drainage system, which indicates everything: the location of collector and storage wells, the cross-section of drainage pipes and their depth, the cross-section of the drainage trench, etc. helpful information. An example of a drainage system plan is shown in the figure.

Let's consider the main stages of creating deep drainage of the site.

Image	Process description
	First of all, the site is marked, in which the position of the main elements of the drainage system is transferred from the plan to the terrain. The routes of the drainage pipes are marked with a tensioned cord, which can immediately be pulled either horizontally or with a slope, which should be in each of the sections.
	A pit is dug for a storage drainage well of the required depth. The bottom of the pit is compacted and 10 cm of sand is poured and compacted onto it. The body of the well is tried on in place.
	A trench is dug in the direction from the well towards the beginning of the main collector pipe, the bottom of which is immediately given the required slope specified in the project, but not less than 2 cm per 1 linear meter of pipe. The width of the trench near the bottom is 40 m. The depth depends on the specific project.
	From the collector trench, trenches are dug for drains that will be connected to the collector pipe. The bottom of the trenches is immediately given the required slope. The width of the trenches in the bottom area is 40 cm. The depth is according to the project. On clayey and loamy soils the average depth of drains is 0.6-0.8 meters, and on sandy ones - 0.8-1.2 meters.
	The locations of rotary and collector inspection manholes are being prepared.
	After checking the depth and required slopes, 10 cm of sand is poured onto the bottom of all trenches, which is subsequently wetted and compacted manually.
	Geotextiles are lined at the bottom of the trenches so that they extend onto the side walls. Depending on the depth of the trench and the width of the geotest fabric, it is fixed either on the walls of the trench or on top.
	The wells are installed and tried on in their places, the places where the couplings are inserted are marked. Then the wells are removed and the necessary couplings are cut into them to connect the drains, and the bottoms are mounted.
	The wells are installed in their places and leveled. A layer of granite crushed stone or washed gravel with a fraction of 20-40 mm and a thickness of 10 cm is poured into the trench. The crushed stone layer is compacted and the necessary slopes are created.
	The required sections of drainage pipes are cut off and equipped with plugs (if necessary). In most cases, beam drains are made from pipes with a diameter of 110 mm, and collector drains – 160 mm. The pipes are laid in trenches and connected to well couplings and fittings. Their depth and slopes are checked.
	A 20 cm layer of crushed stone or washed gravel is poured over the drains. After compaction, the crushed stone layer is covered with geotextiles previously fixed to the walls of the trenches or on top.
	The drainage system is checked for functionality. To do this, in various places where drains are laid, a large amount of water is poured into the trenches. Its absorption into the crushed stone layer and flow through rotary, collector wells and into the main drainage well are controlled.
	A layer of sand is poured over the geotextile, at least 20 cm thick. The sand is compacted, and on top of it the trenches are filled with fertile soil - 15-20 cm.
	Covers are put on the wells.

Even if deep drainage of the site was done without a project, it is still necessary to draw up a plan to indicate the location of the drains and their depth. This will help in the future, when carrying out any excavation work, to leave the system undamaged. If the terrain allows, then drainage wells may not be installed, and the water collected by drains is immediately sent to sewers, reservoirs or a collective storm sewer system. Any of these steps must be coordinated with neighbors and village administrations. But a well is still desirable, at least to control the groundwater level and its seasonal fluctuations.

A collector well for collecting groundwater can be made overflow. When the water level in such wells becomes higher than the overflow pipe, some of the water flows through the sewer pipe into another storage well. This system allows you to get clean water in the storage well, since all the dirt, silt and debris settles in the collector overflow well.

When famous thinkers, called great, whose sayings are constantly quoted and cited as examples, put their thoughts on paper, they probably did not even suspect that they were writing about deep drainage. Here are some examples:

A collective image of a thinker who is known to most people, like Kozma Prutkov, said: “Look at the root!” Great phrase about deep drainage! If the owner wants to grow garden trees on his property, he simply must know where the groundwater lies, since its excess in the area of the root system has a bad effect on most plants.
The very famous thinker and “generator of wisdom” Oscar Wilde also said, without knowing it, about deep drainage: “The biggest vice in a person is superficiality. Everything that happens in our lives has its own deep meaning.”
Stanislaw Jerzy Lec said the following about depth: “A swamp sometimes gives the impression of depth.” This phrase fits drainage perfectly, since without it the area may well turn into a swamp.

We can give many more quotes from great people and connect them with drainage, but we will not distract the readers of our portal from the main idea. For the safety of homes and the comfort of their inhabitants, creating ideal conditions for the growth of necessary plants, and arranging a cozy landscape, drainage is definitely needed.

Conclusion

It should be noted that residents of most regions of Russia are incredibly lucky if the issue of drainage is raised. An abundance of water, especially fresh water, is much better than a lack of it. Residents of arid and desert regions, having read such an article, would sigh and say: “We would like your problems!” Therefore, we simply must consider ourselves lucky that we live in a country that does not lack fresh water.

As we have already noted, you can always “negotiate” with water using the drainage system. The modern market abundance offers a simply gigantic assortment of various components, allowing you to create a system of any complexity. But in this matter one must be very selective and careful, since excessive complexity of any system reduces its reliability. Therefore, we again and again recommend ordering a drainage project from specialists. And the independent implementation of site drainage is within the capabilities of any good owner, and we hope that our article will help in some way.

Page 15 of 21

DRAINAGE SYSTEMS AND DRAINAGES

5.19. When designing drainage systems to prevent or eliminate flooding of territories, the requirements of these standards, as well as SNiP 2.06.14-85 and SNiP II-52-74 must be met.

5.20. When designing drainage systems, preference should be given to drainage systems with water drainage by gravity. Drainage systems with forced pumping of water require additional justification.

Depending on the hydrogeological conditions, horizontal, vertical and combined drainages should be used.

5.21. The drainage system must ensure the groundwater level regime required by the protection conditions: in the territories of populated areas - in accordance with the requirements of these standards, and on agricultural lands - in accordance with the requirements of SNiP II-52-74.

5.22. The use of a drainage system should be justified by studying the water, and for the arid zone, the salt balance of groundwater.

For single-stage design, it is necessary to carry out calculations and analysis of the causes and consequences of flooding specified in clause 1.6. In a two-stage design, based on geological and hydrogeological survey data and research results obtained at the first stage, taking into account the nature of the development and the prospects for development of the protected area, it is necessary to determine the location of the drainage network in plan, the depth of its location and the interconnection of individual drainage lines with each other.

Hydrogeological calculations for the selected drainage schemes should establish:

the optimal position of coastal, head and other drains in relation to the dam or to the boundaries of foundations from the condition minimum values their debits;

the required depth of drains and the distance between them, the flow rate of drainage water, including that to be pumped;

position of the depression curve in the protected territory.

5.23. The implementation of horizontal drainage using open trench and trenchless methods is determined economic feasibility. In the case of installing open horizontal drainages at a depth of up to 4 m from the ground surface, the depth of soil freezing, as well as the possibility of their overgrowing, should be taken into account.

5.24. In all cases of using vertical drainage, its water receiving part should be located in soils with high water permeability.

5.25. Open drainage channels and trenches should be installed in cases where drainage of large areas with one- and two-story low-density buildings is required. Their use is also possible for protecting ground transport communications from flooding.

The calculation of open (trench) horizontal drainage should be made taking into account its combination with a mountain canal or a drainage system collector. In this case, the trench drainage profile should be selected according to the estimated flow rate of surface water runoff during gravity drainage of the area.

To secure the slopes of open drainage ditches and trenches, it is necessary to use concrete or reinforced concrete slabs or rock fill. Drainage holes must be provided in reinforced slopes.

In closed drainages, sand and gravel mixture, expanded clay, slag, polymer and other materials should be used as a filter and filter bedding.

Drainage water should be drained through trenches or channels by gravity. The construction of drainage reservoirs with pumping stations is advisable in cases where the topography of the protected territory has lower elevations than the water level in the nearest water body, where surface runoff from the protected territory should be diverted.

5.26. The following should be used as drainage pipes: ceramic, asbestos-cement, concrete, reinforced concrete or polyvinyl chloride pipes, as well as pipe filters made of porous concrete or porous polymer concrete.

Concrete, reinforced concrete, asbestos-cement pipes, as well as pipe filters made of porous concrete should be used only in soils and water that are non-aggressive towards concrete.

According to the strength conditions, the following maximum depth of laying pipes with filter filling and backfilling of trenches with soil is allowed, m:

ceramic:

drainage with a diameter of 150-200 mm.................. 3.5

" " 300 " .................. 3,0

sewer "150" ................... 7.5

" " 200 " ................... 6,0

" " 250 " ................... 5,5

" " 300 " ................... 5,0

concrete "200" ................... 4.0

" " 300 " ................... 3,5

The maximum depth for laying drainage from pipe filters should be determined by the destructive load in accordance with the requirements of VSN 13-77 “Drainage pipes made of large-porous filtration concrete on dense aggregates,” approved by the USSR Ministry of Energy and agreed with the USSR State Construction Committee.

5.27. The number and size of water intake holes on the surface of asbestos-cement, concrete and reinforced concrete pipes should be determined depending on the water throughput of the holes and drainage flow rate, determined by calculation.

Around drainage pipes it is necessary to provide filters in the form of sand and gravel sprinkles or wraps made of artificial fibrous materials. The thickness and particle size distribution of fishing line and gravel should be selected by calculation in accordance with the requirements of SNiP 2.06.14-85.

5 .28. Release of drainage water into water body(river, canal, lake) should be placed in plan at an acute angle to the direction of the current flow, and its mouth should be provided with a concrete cap or reinforced with masonry or riprap.

Discharge of drainage water into storm sewer allowed if the capacity of the storm sewer is determined taking into account the additional flow of water coming from the drainage system. In this case, back-up of the drainage system is not allowed.

Drainage inspection wells should be installed at least every 50 m in straight sections of drainage, as well as in places of turns, intersections and changes in slopes of drainage pipes. Inspection wells may be used prefabricated from reinforced concrete tracks with a settling tank (at least 0.5 m deep) and concrete bottoms in accordance with GOST 8020-80. Inspection wells on reclamation drainages should be adopted in accordance with SNiP II-52-74.

5.29. Drainage galleries should be used in cases where the required reduction in groundwater levels cannot be achieved using horizontal tubular drains.

The shape and cross-sectional area of the drainage galleries, as well as the degree of perforation of its walls, should be established depending on the required water intake capacity of the drainage.

Drainage gallery filters must be made in accordance with the requirements of clause 5.27.

5.30. Water-reducing wells equipped with pumps should be used in cases where a decrease in the groundwater level can only be achieved by pumping out water.

If a drainage dewatering well cuts through several aquifers, then, if necessary, filters should be provided within each of them.

5.31. Self-flowing wells should be used to relieve excess pressure in confined aquifers.

The design of self-discharging wells is similar to the design of water-reducing wells.

5.32. Water absorption wells and through filters should be installed in cases where underlying soils of high permeability with free-flowing groundwater are located below the aquitard.

5.33. Combined drainages should be used in the case of a two-layer aquifer with a poorly permeable upper layer and excess pressure in the lower layer or with a lateral inflow of groundwater. Horizontal drainage should be laid in the upper layer, and self-flowing wells - in the lower layer.

Horizontal and vertical drains must be located in plan at a distance of at least 3 m from each other and connected by pipes. In the case of drainage galleries, the wellheads should be led into niches arranged in the galleries.

5.34. Radial drainages should be used to deeply lower the groundwater level in densely built-up areas in flooded areas.

5.35. Vacuum drainage systems must be used in soils with low filtration properties in the case of drainage of objects with increased requirements for underground and above-ground premises.

Until now design organizations ,carried out those planning the design of drainage systems (hereinafter referred to as drainages) in Moscow are guided by the “Temporary guidelines for the design of drainages in Moscow ve (N M- 15- 69) » , developed in 1969 “Mosproe who m-1” and “Mosinzhproe who.”

During the practical use of the “Temporary Instructions”, new drainage designs have appeared, based on the use of modern materials, and both positive and negative experience in the design and construction of drainages has been accumulated, which necessitates the development of a new regulatory document.

Application area

The “Guide” is intended for use in the design and construction of drainages of buildings, structures and underground communication channels located in residential microdistricts, as well as for detached buildings and structures.

The “Guidelines” do not apply to the design of shallow road drainages, transport and other special-purpose structures, as well as temporary dewatering during construction work.

a common part

To protect buried parts of buildings (basements, technical undergrounds, pits, etc.), internalquarterly x collectors, communication channels from flooding with groundwater must provide there is drainage and... Con with Drainage structures and waterproofing of the underground part of buildings and structures must be carried out in accordance with SNiP 2.06.15-85,SNiP 2.02.01-83*,MGSN 2.07-97, “Recommendations for the design of waterproofing of underground parts of buildings and structures”, developed by TsNIIPpromzdany in 1996year and the requirements of this “Manual”.

Drainage design should be carried out on the basis of specific data on the hydrogeological conditions of the construction site, the degree of aggressiveness of groundwater to building structures, space-planning and design solutions of protected buildings and structures, as well as the functional purpose of these premises.

Prot And vocapillary waterproofing in walls and coating or painting insulation of vertical wall surfaces,in contact with the ground, must be provided in all cases, regardless of the drainage arrangement.

The installation of drains is mandatory in cases of location :

basement floors ,technical subfields, int. morning and quarterly x collectors, communication channels, etc. below the calculated groundwater level or if the elevation of the floors above the calculated groundwater level is less 50 cm;

floors of exploited basements, intra-quarter collectors, communication channels in clay and loamy soils, regardless of the presenceI groundwater;

floors of basements located in the zone of capillary humidification, when the appearance of water in the basement is not allowed s grow;

floors of technical undergrounds in clay and loamy soils when they are buried more than 1, 3m from the planning surface of the earth, regardless of the presence of groundwater;

floors of technical undergrounds in clayey and loamy soils when they are buried less than 1, 3m from the planning surface of the earth when the floor is located on the foundation slab, as well as in cases where sand lenses approach the building from the upland side or a thalweg is located from the upland side to the building.

To prevent flooding of soil areas and the flow of water to buildings and structures, in addition to the installation of drainages, it is necessary to provide:

standard soil compaction when backfilling pits and trenches;

as a rule, closed outlets of drains from the roof of buildings;

drainage sch there are open trays with a cross-section≥15×15 see with longitudinal slope,≥1% with open drain outlets;

installation of blind areas for buildings wide≥100see with active cross slope from buildings≥2% to roads or trays;

hermetic sealing of holes in external walls and foundations at the inputs and outputs of utility networks;

organized surface runoff from the territory of the designed facility, which does not impair the drainage of rain and melt water from the adjacent territory.

In cases where, due to low elevations of the existing ground surface, it is not possible to ensure the drainage of surface water or to achieve the required reduction of groundwater, provision should be made for filling the area to the required elevations. If it is impossible to drain drainage water by gravity from individual buildings and structures or a group of buildings, it is necessary to provide for the installation of pumping stations for pumping drainage water.

The design of drainages for new facilities should be carried out taking into account existing or previously designed drainages of adjacent territories y.

If there is a general decrease in the groundwater level in the microdistrict, the marks for the reduced groundwater level should be set at 0, 5m below the floors of basements, technical undergrounds, communication channels and other structures. If a general lowering of the groundwater level is impossible or impractical, local drainage should be provided for individual buildings and structures (or groups of buildings)).

Local drainages, as a rule, should be installed in cases of significant deepening underground floors separatelys x buildings if it is impossible to remove drainage water by gravity.

Types of drains

Depending on the location of the drainage in relation to the aquifer, drainages can be of a perfect or imperfect type.

Perfect type drainage is laid on aquifer. Groundwater enters the drainage from above and from the sides. In accordance with these conditions, a perfect type of drainage must have a drainage layer on top and on the sides (see Fig.).

An imperfect type of drainage is laid above the aquifer. Groundwater enters drainages from all sides, so drainage filling must be carried outh closed on all sides (see fig.).

Initial data for drainage design

To draw up a drainage project, the following data and materials are required:

technical report on hydrogeological conditions of construction;

scale plan of the territory 1: 500with existing and planned buildings and underground structures;

relief organization project;

plans and floor marks of basements and subfloors of buildings;

plans, sections and developments of building foundations;

plans ,longitudinal profiles and sections of underground channels.

The technical report on the hydrogeological conditions of construction should contain the characteristics of groundwater, geologicalG o-lithological structure of the site and physical and mechanical properties of soils.

The groundwater characteristics section should indicate:

reasons for the formation and sources of recharge of groundwater;

groundwater regime and marks of the appeared, established and calculated levels of groundwater, and, if necessary, the height of the zone of capillary moistening of the soil;

chemical analysis data and conclusion on the aggressiveness of groundwater in relation to concrete and mortar A m.

The geological and lithological section provides a general description of the structure of the site.

The characteristics of the physical and mechanical properties of soils should indicate:

granulometric composition of sandy soils;

filtration coefficients of sandy soils and sandy loams;

porosity and fluid loss coefficients;

angle of repose and bearing capacity of soils.

The conclusion should be accompanied by the main geological sections and soil “columns” from the boreholes, necessary for compiling geological sections along the drainage routes.

If necessary, in difficult hydrogeological conditions for drainage projects of blocks and microdistricts to technical report a hydroisohypsum map and a soil distribution map must be attached.

In the case of special requirements for the drainage device caused by the specific operating conditions of the protected premises and structures, these requirements must be set forth by the customer as additional source materials for drainage design.

General conditions for choosing a drainage system

The drainage system is selected depending on the nature of the protected object and hydrogeological conditions.

When designing new blocks and microdistricts in areas with high groundwater levels, it should be developed general scheme drainage.

The drainage scheme includes drainage systems,ensuring a general decrease in the level of groundwater in the territory of the block (microdistrict), and local drainages to protect individual structures from flooding by groundwater y.

Drainages that ensure a general decrease in groundwater levels include drainages:

head or shore;

systematically

Local drainages include drainages:

annular;

wall;

layers y.

Local drainages also include drainages intended forh protection of individual structures:

drainage of underground channels;

pit drainage;

road drainage;

drainage of backfilled rivers, streams, ravines and ravines;

slope and wall s th drainages;

drainage of underground parts of existing buildings.

Under favorable conditions (in sandy soils, as well as in sandy layers with large area their distribution) local drainages can simultaneously contribute to a general decrease in groundwater levels.

In areas where groundwater occurs in sandy soils,Drainage systems should be used to ensure a general decrease in the groundwater level.

In this case, local drainages should be used to protect individual especially buried structures from flooding with groundwater.

In areas where groundwater lies in clayey, loamy and other soils with low water yield, it is necessary to arrange local drainage And.

Local “preventive” drainages should also be installed in the absence of observable groundwater to protect underground structures locatedl agae in clayey and loamy soils.

In areas with a layered aquifer structure, both general drainage systems and local drainages should be installed.

General drainage systems should be installed to drain water-logged sandy layers through which water enters the drained area. In this system, separate local drainages can also be used, with a depression radiusn The new curve covers a significant area of territory. Local drainages must be installed for underground structures laid in areas where the aquifer is not completely drained common system drainage, as well as in places in h possible appearance of perched water.

In built-up areas, during the construction of individual buildings and structures that need protection from groundwater flooding, local drainage must be installed. The design and construction of these drains must take into account their impact on adjacent existing structures.

Head drainage

To drain areas flooded by a flow of groundwater with a recharge area located outside this territory, head drainage should be installed (see Fig.).

The head drainage must be laid along the upper, in relation to the underground flow, border of the drained area. The drainage route is designated taking into account the location of the building and is carried out, if possible, in places with higher elevations in d support

The head drain should, as a rule, cross the groundwater flow along its entire width.

When the length of the head drainage is less than the width of the underground flow, additional drains should be installed along the lateral boundaries of the drained area in order to intercept groundwater flowing from the side.

If the aquitard is shallow, the head drainage should be laid on the surface of the aquitard (with some penetration into it) in order to completely intercept groundwater, like a perfect type of drainage.

In cases where it is not possible to lay drainage on an aquiclude, and drainage conditions require that the flow of groundwater be completely intercepted, a screen made of a waterproof sheet piling is installed below the drainage, which must be lowered below the aquitard level.

When the aquitard is deep, the head drainage is laid above the aquifer, as an imperfect type of drainage. In this case, it is necessary to calculate the depression curve. If the installation of one head drainage line does not achieve a decrease in the groundwater level to the specified levels, a second drainage line should be laid parallel to the head drainage. The distance between drainages is determined by calculation.

If the part of the aquifer located above the drainage consists of sandy soils with a filtration coefficient of less than 5m /from ut ki, the lower part of the drainage trench must be filled with sand with a filtration coefficient of at least 5 m/day (see fig.).

The height of sand filling is 0,6 - 0,7H, where: H is the height from the bottom of the drainage trench to the unreduced design groundwater level.

If part of the aquifer located above the drainage has a layered structure, with alternating layers of sand and loam, backfill the drainage trench with sand with a filtration coefficient of at least5m/day must be made on 30see above for the unreduced design groundwater level.

Backfilling with sand can be carried out over the entire width of the vertical trenchl with a thin or inclined prism, with a thickness of at least 30see. For perfect type head drainage, when the aquifer does not have clay, loamy and sandy loam layers, a sand prism can be installed only on one side of the trench (from the side of the water inflow).

If the head drainage is laid in the thickness of relatively weakly permeable soils, underlying well-permeable soils, a combined drainage should be installed, consisting of a horizontal drain and vertical self-flowing wells (see Fig.).

Vertical wells must be connected by their base to the permeable soils of the aquifer, and by their upper part to the inner layer of the horizontal drain bedding.

For draining coastal areas that are flooded due to backwater in rivers and reservoirs,Coastal drainage should be installed (see Fig.), where the symbols are: M G - low-water horizon of the reservoir, G P B is the horizon of backed-up waters of the reservoir.

Coastal drainage is laid parallel to the shore of the reservoir and laid below the normally supported horizon (NP D) a reservoir by an amount determined by calculation.

If necessary, head and bank drainages can be used in combination with other drainage systems.

Systematic drainage

In areas where groundwater does not have a clearly defined flow direction, and the aquifer is composed of sandy soils or has a layered structure with open sand layers, systematic drainage should be arranged (see Fig.).

The distance between systematic drainage drains and their depth are determined by calculation.

In urban conditions, systematic drainage can be arranged in combination with local drainage. In this case, when designing individual drains, it is necessary to decide on the possibility of oneV temporary use as local drainage, protecting individual structures and as elements of systematic drainage, ensuring a general decrease in the groundwater level in the drained area.

When laying drains for systematic drainage in the thickness of soil with weak water permeability, underlying well-permeable soils, combined drainage should be used, consisting of horizontal drains with vertical,self-flowing wells (see fig.).

In areas flooded by groundwater flows, the recharge area of which also covers the drained area, head and systematic drainage should be used together.

Ring drainage

Ring drainages should also be installed to protect especially damaged basements in new neighborhoods and microdistricts when the depth of the groundwater level drop is insufficient by the general drainage system of the territory.

With good water permeability of sandy soils, as well as when laying drainage on an aquifer,it is possible to arrange a common ring drainage for a group of neighboring buildings.

With a clearly expressed one-way influx of groundwater, drainage can be arranged in the form of an open circuit.l tsa according to the type of head drainage.

Ring drainage must be laid below the floor of the protected structure to a depth,determined by calculation.

If the building is large or when several buildings are protected by one drainage, as well as in the case of special requirements for the reduction of groundwater under the protected structure, the depth of the drainage is taken in accordance with the calculation, in which the excess of the reduced groundwater level in the center of the ring drainage contour must be determined above the water level in the drain. If the drainage depth is insufficient, intermediate “cut” drains should be installed.

Ring drainage should be laid at a distance 5 - 8m from the wall of the building. With a smaller distance or greater depth of drainage, it is necessary to take measures against the removal,weakening and settlement of the soil under the building foundation I

Wall drainage

To protect basements and subfloors of buildings laid in clay and loamy soils from groundwater, wall drainages should be installed.

Wall “preventive” drainages must also be installed in the absence of groundwater in the area of basements and underground areas located in clayey and loamy soils.

If the aquifer has a layered structure, wall or ring drains should be installed to protect basements and subfloors of buildings, depending on local conditions.

If individual parts of the building are located in areas with different geological conditions, in these areas it can be used as a ring,and wall drainage.

Wall drainage is laid along the contour of the building from the outsides. The distance between the drainage and the wall of the building is determined by the width of the building foundations and the placement of drainage inspection wells.

Wall drainage, as a rule, should be laid at levels not lower than the bottom of the strip foundation or the base of the foundation slabs s.

If the foundations are laid at a great depth from the basement floor level, wall drainage can be laid above the base of the foundations, provided that measures are taken to prevent drainage subsidence.

Installation of wall drainage using modern polymer filter materials, in particular using the “Dreniz” casing», reduces construction costs by saving sand.

The Dreniz shell consists of a two-layer structure: a special profile sheet made of polymer material (polyethylene, polypropylene, polyvinAnd lchloride) and non-woven geotextile filter material, fastened together by welding or waterproof glue. Shell sheets"Dreniz" overlap each other Art.

The technology for using this material is indicatedV Instructions VSN 35-95.

Formative drainage

To protect against flooding by groundwater the basements and subfloors of buildings located in difficult hydrogeological conditions, such as: in aquifers of high thickness, with a layered structure of the aquifer, in the presence of pressurized groundwater, etc., as well as in the case of insufficient effectiveness of using ring or wall drainage, reservoir drainage should be installed (see Fig.).

In aquifers of large thickness, it is necessary to first calculate the possible decrease in the groundwater level in the center of the ring drainage contour. In case of insufficient reduction of groundwater level, it is necessary to apply layers s th drainage.

If the structure of the aquifer is complex, with changes in its composition and water permeability (in plan and section), as well as in the presence of watered closed zones and lenses under the basement floor, reservoir drainages are installed.

In the presence of pressurized groundwater, ring or reservoir drainage should be used depending on local hydrogeological conditions with calculation justification.

To protect basements and structures in which, due to operating conditions, the appearance of dampness is not allowed, when laying these premises in the zone of capillary soil moisture, formation drainage should be installed.

Layered “preventive” drainages for such premises and structures located in clayey and loamy soils are also recommended to be provided in the absence of observable groundwater.

Reservoir drainages are installed in combination with tubular drainages (ring and wall).

To connect reservoir drainage with external tubular drainage, a tubular drainage is laid through the foundations of the building.

For underground buildings with foundations on pile grillages, reservoir drainage can be installed in combination with a single-line drainage laid under the building.

Drainage of underground channels

To protect heating network channels and collectors of underground structures from flooding by groundwater when laying them in aquiferous soils, it is necessary to install linear accompanying drainages.

“Preventive” (accompanying) drainages should be installed in clayey and loamy soils.

The accompanying drainage must be laid on 0,3 - 0,7 m below the base of the canal.

The accompanying drainage should be laid on one side of the channel at a distance 0, 7 - 1, 0m from the outer edge of the channel. Distance 0, 7m is necessary to place inspection wells.

When installing passage channels, drainage can be laid under the channel along its axis. In this case, special inspection rooms should be installed on the drainage.l boats with hatches sealed in the bottom of the canal.

In the case of laying the foundation of a canal on clay and loamy soils, as well as on sandy soils with a filtration coefficient of less than5m/day, under the base of the canal it is necessary to arrange layers s th drainage in the form of a continuous sand layer.

The reservoir drainage must be connected to the drainage bedding of the accompanying tubular drainage.

When constructing channels in clay and loamy soils,V soils with a layered structure, as well as in sandy soils with a filtration coefficient of less than 5m/day, both sides of the canal must be filled V vertical or inclined prisms made of sand with a filtration coefficient of at least e5 m/day.

Sand prisms are intended to receive water flowing from the sides and are arranged similarly to the sand prisms of the head and wall drainages.

Drainage of pits and buried parts of basements

Drainage of pits and recessed parts of basements must be decided in each case depending on local hydrogeological conditions and adopted building designs.

deepening of the lower section of the drainage, when buried rooms and pits are located at its lower part, counting along the flow of water in the drainage;

a general decrease in drainage when laying drainage and protected structures in sandy soils;

dividing the general drainage into separate parts with independent outlets; installation of additional local drainages.

When draining individual pitsV and buried premises, it is necessary to pay special attention to measures against the removal of soil from under the foundations of the building.

When installing ring drains, the foundations of the building can be laid slightly above the drainage. The excess of the building foundations above the drainage and the distance of the drainage from the building must be checked taking into account the angle of internal friction of the soil according to the formula:

Where

l min - the smallest distance of the drain axis from the wall of the building in m,

b - widened And e of the building foundation in m,

B is the width of the drainage trench in m,

H is the depth of the drain in m,

h - foundation depth in m,

φ - angle of internal friction of the soil.

When laying drainage below the foundation of buildings in order to prevent soil suffusion, Special attention should pay attention to the correct selection and installation of drainage bedding, the quality of sealing of seams and holes in wells,as well as for measures to prevent the removal of soil when digging drainage trenches.

If there is a large drop in the groundwater horizon under foundations (existing and planned), the soil settlement should be calculated.

When constructing differences in drainage within the zone of influence of the lower drain, the measures listed above should also be taken into account.

Drop s Wells must be installed with careful sealing of all seams and holes.

Local drainage for individual pits is recommended to be arranged according to the type of reservoir drainage.

Other types of drainage

In some cases, the required reduction in groundwater levels can be achieved by a system of general drainage of the territory (head and systematic drainage).

Drains can be laid together with gutters (see fig.).

When filling rivers, streams, ravines and ravines, which are natural drainage of groundwater, in addition to collectors for draining surface water, it is necessary to install drainages to receive groundwater.

Drains must be provided with a connection to the aquifer on both sides of the drainage collector. With a large influx of groundwater,and also when laying a collector on clay and loam, two drains are laid, placing them on both sides of the collector.

If the groundwater inflow is low and the drainage collector is located in sandy soils, one drain can be laid, positioning it on the side of the larger water inflow. If sandy soils have a filtration coefficient less than5m/day, a layer must be constructed under the base of the reservoir s th drainage in the form of a continuous layer or individual prisms.

When the aquifer wedges out on slopes and slopes, it is necessaryd imo arrange intercepting drainage And.

Intercepting drains are laid at a depth no less than the freezing depth and are arranged like a head drain.

When aquifers are not clearly expressed and groundwater wedges out over the entire area of the slope, speciale slope drainages.

When installing retaining walls, in places where groundwater wedges out, a wall is installedth drainage. Zast oh This drainage is a continuous backfill of filter material laid behind the wall. If the length is short, wall drainage can be installed without a pipe. For significant lengths, it is recommended to install tubular drainage with drainage bedding.

To catch springs that wedge out on a slope, capture wells are installed.

Sloping and walls Drainages and capture wells must have secured water outlets.

To protect existing basements and subfloors of buildings, the type of drainage is chosen on a case-by-case basis, guided by local conditions.

In sandy soils, ring and head drainages are installed.

In clay and loamy soils at deepO When laying foundations, wall drainage is arranged, provided that such a solution is allowed by the design of the foundations and walls of the building.

Plastov m drainage is arranged in case,when a second floor can be installed in the basement at higher elevations. In this case, a layer of filter material (coarse sand with gravel or crushed stone prisms) is poured between the old and new floors and connected to an external tubular drainage, as in conventional reservoir drainages.

When designing and constructing drainages for existing buildings, measures must be taken against the removal and subsidence of soil.

In these cases, the excavation of the drainage trench should be carried out in short sections with immediate laying of the drainage and backfilling of the trench.

Drainage route

The routes of ring, wall and accompanying drainages are determined by reference to the protected structure.

The routes of head and systematic drainages are determined in accordance with hydrogeological conditions and building conditions.

When laying drainage below the base of the foundations of adjacent structures and networks, the distances between them must be checked taking into account the anglel and the natural slope of the soil from the edge of the base of the foundation of the structure (or network) to the edge of the drainage trench (see).

Longitudinal drainage profile

The depth of drainage should be no less than the depth of soil freezing.

The depth of the head, ring and systematic drainages is determined by hydraulic calculations and the depth of the protected buildings and structures.

The depth of wall and associated drainages is determined in accordance with the depth of the protected structures.

The greatest drainage slopes should be determined based on the maximum permissible water flow rate in the pipes- 1, 0 m/s k.

Placement of inspection wells

Viewings e wells should be installed in places where the route turns and slopes change, at drops, as well as between uh these points at large distances.

On straight drainage sections, the normal distance between inspection wells is40m. The greatest distance between drainage inspection wells is 50 m.

At drainage turns near building ledges and at chambers on canals, the installation of inspection wells is not necessary, provided that the distance from the turn to the nearest inspection well is no more20m. In the case where the drainage makes several turns in the area between inspection wells, inspection wells are installed through one turn.

Release device

Water is released from drains into drains, reservoirs and ravine And.

The connection of drains to gutters, as a rule, should be carried out higher w ate gi of the drain. If drainage is connected below went s gi drain pipes, Location on When drainage is released, a check valve must be provided. It is not recommended to connect drainage to drains below the water level in the latter during periods of excess 3 times a year.

When released into a reservoir, the drainage must be laid above the water horizon in the reservoir during a flood. In case of a short-term rise in the horizon of a reservoir, drainage, if necessary, can be laid below the flood horizon, provided that the drainage release is equipped with a check valve.

The mouth section of the drainage outlet into the reservoir must be buried below the water horizon to the thickness of the ice cover with the installation of a drop well.

If it is impossible to release water from the drainage by gravity, it is necessary to provide a pumping station (installation) for pumping drainage V od, working in automatic mode.

Combining drainage with drainage

When designing drainage, you should consider the option ofTo fix it together with the drain (see fig.).

If the drainage depth is sufficient, the drainage should be located above the drainage in the same vertical plane with drainage water discharged into each inspection well of the drainage system. The clear distance between the drainage and drainage pipes must be at least 5cm.

If it is impossible, due to the depth of the installation, to place the drainage above the drain, the drainage should be laid in parallel in the same trench with the drain.

Pipes

Asbestos-cement pipes should be used for drainage.

The exception is drainage laid in groundwater, which is aggressive to concrete and Portland cement mortars. In this case, plastic pipes should be used for drainage.

The permissible maximum backfill depths to the top of the pipe drainage depend on the design resistance of the load-bearing soil, pipe material, pipe laying methods (natural or artificial foundation) and trench backfill, as well as other factors.

Necessary data on the use of asbestos st cement x pipes are available in the album SK 2111- 89, and through plastic pipes - in the SK album 2103- 84.

Water inlet openings in pipes should be arranged in the form of cuts with a width 3 - 5mm. The length of the cut should be equal to half the diameter of the pipe. The cuts are made on both sides of the pipe in a checkerboard pattern. Distance between holes on one side - 50see. There is an option with drilling water inlet holes (see fig.,).

When laying pipes, it is necessary to ensure that the cuts are on the side of the pipe; the top and bottom of the pipe should be without cuts.

Asbestos-cement pipes are connected with couplings.

When using polyvinyl chloride s x pipes (P V X) water intake holes are made similarly to asbestos-cement s m pipes. Corrugated drainage pipe made of polyethylene (HDPE) is produced with ready-made water inlet holes (see fig.).

Drainage structures and drainage filters

Drainage bedding, in accordance with the composition of the drained soils, is arranged in single or double layers.

When placing drainage in sand, gravel sheets x, large and medium size (with an average particle diameter 0, 3 - 0, 4mm and larger) arrange single-layer gravel or crushed stone.

When drainage is located in medium-sized sands with an average particle diameter less than 0, 3 - 0, 4mm, as well as in small and p ylevat s In sands, sandy loams and with a layered structure of the aquifer, two-layer bedding is arranged (see Fig. 20). The inner layer of the sprinkling is made of crushed stone, and the outer layer of the sprinkling is made of sand.

Drainage fill materials must meet the requirements for materials for hydraulic structures.

For inner layer dren gravel is used as a filling coating, and in the absence of e G o - crushed stone of igneous rocks (granite, syenite, gabbro, liparite, basalt, diabase, etc.) or especially durable varieties of sedimentary rocks (siliceous limestones and well-cemented non-weathering sandstones).

Sands, which are a product of weathering of igneous rocks, are used for the outer layer of bedding.

Materials for drainage bedding must be clean and not contain more than 3- 5% by weight of particles with a diameter less than 0.1 mm.

The composition of drainage fills is selected according to special schedules depending on the type of filter and the composition of the drained soil.

Drains should be laid in drained trenches. In sandy soils, water reduction using wellpoints is used. When laying drainage on an aquifer, dewatering with the installation of construction drains, freezing or chemical consolidation of soils are used.

Imperfect type drainage pipes are laid on the lower layers of drainage fill, which in turn are laid directly on the bottom of the trench.

For perfect type drainages, the base (bottom of the trench) is strengthened with crushed stone compacted into the ground, and the pipes are laid on layers of sand a thickness of 5cm.

In weak soils with insufficient bearing capacity, drainage should be laid on an artificial foundation.

Drainage bedding can have a rectangular or trapezoidal shape in cross section.

Rectangular sprinklings are arranged using inventory boards.

Sprinkles of a trapezoidal shape are poured without shields with slopes 1:1.

The thickness of one layer of drainage coating must be at least 15cm.

Pipe filters

Instead of installing drainage from pipes with gravel sch baby As a filter for preventive drainage, pipe filters made of porous concrete or other material can be used. The area and conditions of use of pipe filters are determined by special instructions.

Wells

On Wells are installed in tubular drainages.

Dl I protection from h To prevent weeds, wells must be equipped with second covers.

Drop s Drainage wells must have a water feature.

Sand prisms

When laying drainage in sandy soils With filtration coefficient less5m/day, as well as in soils with a layered structure, part of the trench above the drainage is covered with sand. The filled sand prism must have a filtration coefficient of at least 5 m/day

A trench dug in sandy soils is backfilled with sand to a height 0, 6 - 0, 7H, where H is the height from the bottom of the trench to the groundwater level, but not less 15see above the top of the drainage bedding. In soils with a layered structure, the trench is filled with sand 30see above the groundwater level (see Fig.).

Filter wells

If the structure of the aquifer is heterogeneous, when a horizontal drain runs in the upper less permeable layer, and a more permeable layer is located below, a combined drainage is arranged, consisting of a horizontal drain and vertical self-flowing filter wells (see Fig.).

Drilling of vertical filter wells can be done hydraulically (by immersion using a submersibleV a) or by drilling method m. In these cases, filter wells are constructed structurally similar to tube wells for vertical drainage. The mouth (upper end of the tube well) is located below the general unreduced groundwater level and is embedded in the bottom of the drainage inspection well. The mark of the mouth of the tube well should be higher than the mark of the horizontal drain tray on 15cm. At shallow depths, filter wells can be installed open method. For this purpose, wells are opened from the bottom of the horizontal drainage trench, in which pipes (asbestos) are installed vertically cement e or plastic) filled with gravel or crushed stone. The space between the vertical pipe and the ground is filled with coarse sand. The lower end of the vertical pipe enters the layer of gravel or crushed stone at the bottom of the well A. The upper end of the pipe mates with the inner layer of the horizontal drain.

Reservoir drainage design

Plastov s th drainage is used to protect building basements, pits and canals in cases where tubular drainage alone does not provide the necessary drainage effect.

Reservoir drainage is arranged in the form of a layer of sand poured along the bottom of a pit under a building or a trench for a canal.

The layer of sand is cut through in the transverse direction with prisms made of gravel or crushed stone.

Reservoir drainage must be protected from clogging during constructionA. When constructing floors and foundations using the wet method (using monolithic concrete and cement mortars), it is necessary to close the layers s and drainage with insulating material (glassine, etc.) P.).

Gravel (or crushed stone) prisms must have a height of at least 20cm.

Distance between prisms -6÷12 m (depending on hydrogeological conditions). Prisms are being laid, usually , in the middle between the transverse foundations of the building.

With a large influx of water or for particularly critical reservoir structuress th drainage can be two-layer over the entire area with a bottom layer of sand and a top layer of gravel and whether crushed stone.

If the width of the protected structure is small and the influx of water is limited, in particular under underground channels, reservoir drainage can be constructed from a single layer of sand or crushed stone.

The thickness of reservoir drainage under buildings must be at least30cm, and under the channels - no less 15 cm.

In some cases, with a large drainage area or special requirements for reducing the capillary saturation zone, the thickness and design of reservoir drainage are determined by calculation.

Reservoir drainage should extend beyond the outer walls of the structure, and, if necessary, be poured along the slope of the pit (trench).

The reservoir drainage must be connected to a ring, wall or accompanying tubular drainage.

For large areas And subtext In large rooms, additional tubular drains should be laid under the floor of the room.

In the undergrounds of buildings erected on pile foundations, reservoir drainage can be arranged in combination with a single-line tubular drainage located under the underground m

Pumping stations (installations) for pumping out drainage water

The depth of the underground premises of residential and public buildings and structures does not always allow drainage water to be directed by gravity into the storm sewer. In this case, it is necessary to install drainage pumping stations. When designing drainage pumping stations, the following should be taken into account:

The installation of free-standing pumping stations (installations), as a rule, is not economically feasible, because the costs of their construction and operation will be significantly higher than those built into basements;

pumping installations should mainly be located in buildings from which it is not possible to direct drainage water into the storm sewer (gutter) by gravity;

During a feasibility study, it is possible to install one pumping station for pumping drainage water from several buildings. Ifh Denmark will belong to different owners, to resolve this issue it is necessary to obtain the appropriate document on equity participation in the construction and operation of a common pumping station, formalized in the prescribed manner.

When deciding on the placement of pumping stations for pumping drainage water, the priority is to comply with permissible levels of noise and vibration from pumping units and pipelines in apartments of residential buildings and public premises.

Pumping installations should not be located: under residential apartments, children's or group rooms of kindergartens and nurseries, classrooms of secondary schools, hospital premises, workrooms of administrative buildings, classrooms of educational institutions and other similar premises.

In projects, it is necessary to make appropriate noise and vibration calculations that determine the choice of technical measures to ensure compliance with the requirements for permissible noise and vibration levels in residential and public areas of buildings in accordance withMGSN 2.04-97 , manuals for MGSN 2.04-97 “Design of protection from noise and vibration of engineering equipment in residential and public buildings” and “Design of sound insulation of enclosing structures of residential and public buildings.”

The flow rates of drainage water sent to the pumping station must be determined specifically for each facility.

As a rule, the installation should include two pumping units, of which one is a reserve one. If justified, installation of a large number of pumps is allowed. When there is limited space to accommodate a pumping station, it is most advisable to use submersible pumps.

The drainage pumping station must have a special room necessary to accommodate the receiving tank, pumping units and other equipment.

Only personnel servicing the installed equipment should have access to the pumping station.

The operation of pumping stations should be provided in automatic mode.

Capacity of receiving tanks withl should be determined depending on the calculated second flow rate of drainage water, the performance of the selected pump or pumps and the permissible frequency of switching on the pump electric motor, but not less 5- its maximum minute performance (for domestic pumps). The maximum number of starts per hour for imported pumps must be indicated in technical documentation manufacturer's company. If this data is not available, a corresponding request should be made.

To reduce the frequency of pump activation, their alternate operation can be provided. In this case, it is necessary to provide3-th reserve pump, which can be stored in a warehouse. Considering that drainage water, as a rule, is relatively clean, it is possible not to provide a special pipeline for stirring up the sediment in the tank. For contaminated water or if it is necessary to regulate the flow of wastewater pumped by pumps, the specified pipeline should be provided.

To automate and dispatch the operation of pumping units, appropriate water levels are assigned in the receiving tank of the pumping station.

Worker and reserve activation levels var pumps must be installed below the supply pipeline tray. In this case, the activation level of the backup pump is assigned higher than the working one, because it should turn on not only during an emergency stop of the working pump, but also when the influx of water increases and, accordingly, its level in the tank increases (i.e. if the productivity of the working pump is less than the increased influx of wastewater).

In the event of a further increase in the water level due to an emergency stop of the pumps or for other reasons, an upper emergency level is assigned, upon reaching which an alarm is generated.

Upper AvaR level usually taken at the elevation of the supply pipeline tray.

Pump shutdown level must be at a distance of at least 2D in from the bottom of the suction pipe (inlet), and the inlet must be located at least 0.8 D in from the bottom of the tank A.

These rules l but it is necessary to comply T b for a favorable supply of water to the vertical suction pipeline and to avoid the entry of air into it.

Lower emergency at level is taken in the interval between the pump shutdown level and the inlet of the suction pipelines.

When applied to a blade installations x horizontal or vertical pumps, the geometric suction height of the pumps must be taken into account.

Each pump must haveV oh suction pipe.

Suction pipes must be sealed. Welded joints are the most preferred.

To prevent the formation of water in the suction pipeh stuffy bags, the pipeline is laid with a rise towards the pump (slope of at least 0, 005). For the same reason, when transitioning from one diameter to another in horizontal sections, only “oblique” transitions with a horizontal upper generatrix (eccentric transition) are used.

Pressure pipelines, after installing check valves and gate valves on them, as a rule, should be combined into one pipeline.

When using submersible pumps, the lower shutdown level must be taken not lower than that specified in the technical documentation of the manufacturer.

Notes :

1.In Fig. and examples of solutions for wall drainage using drainage systems are presented.“DRENIZ” shells and drainage on pile foundation with filling the sinuses with sand.

2. It is recommended to use methods for hydrogeological and hydraulic calculations of drainage from the sources given in the appendix.

MGSN 2.07-97 “Foundations, foundations and underground structures”

VSN-35-95 “Instructions for the technology of using polymer filter shells to protect underground parts of buildings and structures from flooding with groundwater”, Research Institute M acute

Album No. 84 Institute Mosinzhproekt "Drainages for l I drain urban areas and protect underground structures"

Album SK 2111 - 89Mosinzhproekt Institute “Underground non-pressure pipelines made of asbestos-cement, ceramic and cast iron pipes”

Album SK 2103 - 84Mosinzh Institute project “Underground free-flow pipelines made of plastic pipes”

Designer's Handbook "Complex foundations and foundations" M., 1969G.

Abramov S .TO . "Underground drainage in industrial and civil construction" M., 1967

Degtyarev B. M. and others. “Protection of the foundations of buildings and structures from the effects of underground water" Stroyizdat, 1985

MGSN 2.04-97 “Permissible levels of noise, vibration and requirements for sound insulation in residential and public buildings”

THE GOVERNMENT OF MOSCOW
MOSKOMARCHITECTURE

MANAGEMENT
for designing drainage of buildings and structures

1. DEVELOPED by Mosproekt JSC (engineers L.K. Kiskin, E.N. Chernyshev, V.M. Kovylyaev).

2. Prepared for publication by the Department of Advanced Design and Standards of the Moscow Architecture Committee (eng. Ionin V.A., Shchipanov Yu.B.).

3. APPROVED AND PUT INTO EFFECT by the instruction of the Moscow City Architecture Committee dated November 20, 2000 N 48

Introduction

Until now, design organizations designing drainage systems (hereinafter referred to as drainages) in Moscow are guided by the “Temporary guidelines for the design of drainages in Moscow (NM-15-69)”, developed in 1969 by “Mosproekt-1” and "Mosinzhproekt".

During the practical use of the "Temporary Instructions", new drainage designs have appeared based on the use of modern materials, both positive and negative experience in the design and construction of drainages has been accumulated, which necessitates the development of a new regulatory document.

Application area

The “Guide” is intended for use in the design and construction of drainages of buildings, structures and underground communication channels located in residential neighborhoods, as well as for detached buildings and structures.

The “Guide” does not apply to the design of shallow road drainages, transport and other special-purpose structures, as well as to temporary dewatering during construction work.

a common part

To protect the buried parts of buildings (basements, technical undergrounds, pits, etc.), intra-block collectors, communication channels from flooding with groundwater, drainage must be provided. Drainage structures and waterproofing of the underground parts of buildings and structures must be carried out in accordance with SNiP 2.06.15-85, SNiP 2.02.01-83*, MGSN 2.07-97, “Recommendations for the design of waterproofing of underground parts of buildings and structures”, developed by TsNIIPpromzdany in 1996, and the requirements of this “Manual”.

Drainage design should be carried out on the basis of specific data on the hydrogeological conditions of the construction site, the degree of aggressiveness of groundwater to building structures, space-planning and design solutions of protected buildings and structures, as well as the functional purpose of these premises.

Anti-capillary waterproofing in walls and coating or painting insulation of vertical surfaces of walls in contact with the ground must be provided in all cases, regardless of the drainage arrangement.

The installation of drains is mandatory in the following locations:

basement floors, technical undergrounds, intra-block collectors, communication channels, etc. below the calculated groundwater level or if the elevation of the floors above the calculated groundwater level is less than 50 cm;

floors of exploited basements, intra-block collectors, communication channels in clay and loamy soils, regardless of the presence of groundwater;

basement floors located in the capillary humidification zone, when dampness is not allowed to appear in the basements;

floors of technical undergrounds in clay and loamy soils when they are buried more than 1.3 m from the planning surface of the earth, regardless of the presence of groundwater;

floors of technical undergrounds in clayey and loamy soils when they are buried less than 1.3 m from the planning surface of the earth when the floor is located on the foundation slab, as well as in cases where sand lenses approach the building from the upland side or a thalweg is located from the upland side to the building.

To prevent flooding of soil areas and the flow of water to buildings and structures, in addition to the installation of drainages, it is necessary to provide:

standard soil compaction when backfilling pits and trenches;

as a rule, closed outlets of drains from the roof of buildings;

drainage open trays with a cross-section of 15x15 cm with a longitudinal slope of 1% with open drainage outlets;

arrangement of blind areas near buildings with a width of 100 cm with an active transverse slope from buildings of 2% to roads or trays;

hermetic sealing of holes in external walls and foundations at the inputs and outputs of utility networks;

organized surface runoff from the territory of the designed facility, which does not impair the drainage of rain and melt water from the adjacent territory.

In cases where, due to low elevations of the existing ground surface, it is not possible to ensure the drainage of surface water or to achieve the required reduction of groundwater, provision should be made for filling the area to the required elevations. If it is impossible to drain drainage water by gravity from individual buildings and structures or a group of buildings, it is necessary to provide for the installation of pumping stations for pumping drainage water.

The design of drainage for new facilities should be carried out taking into account existing or previously designed drainage in adjacent areas.

With a general decrease in the groundwater level in the microdistrict, the levels of the reduced groundwater level should be set 0.5 m below the floors of basements, technical undergrounds, communication channels and other structures. If a general lowering of the groundwater level is impossible or impractical, local drainage should be provided for individual buildings and structures (or groups of buildings).

Local drainages, as a rule, should be installed in cases of significant deepening of the underground floors of individual buildings when it is impossible to remove drainage water by gravity.

Types of drains

Depending on the location of the drainage in relation to the aquifer, drainages can be of a perfect or imperfect type.

Perfect type drainage is laid on aquifer. Groundwater enters the drainage from above and from the sides. In accordance with these conditions, a perfect type of drainage must have a drainage layer on top and on the sides (see Fig. 1).

An imperfect type of drainage is laid above the aquifer. Groundwater enters the drains from all sides, so the drainage filling must be closed on all sides (see Fig. 2).

Initial data for drainage design

To draw up a drainage project, the following data and materials are required:

technical report on hydrogeological conditions of construction;

site plan on a scale of 1:500 with existing and planned buildings and underground structures;

relief organization project;

plans and floor marks of basements and subfloors of buildings;

plans, sections and developments of building foundations;

plans, longitudinal profiles and sections of underground channels.

The technical report on the hydrogeological conditions of construction should contain the characteristics of groundwater, the geological and lithological structure of the site and the physical and mechanical properties of the soil.

The groundwater characteristics section should indicate:

reasons for the formation and sources of recharge of groundwater;

groundwater regime and marks of the appeared, established and calculated levels of groundwater, and, if necessary, the height of the zone of capillary moistening of the soil;

chemical analysis data and conclusion on the aggressiveness of groundwater in relation to concrete and mortars.

The geological and lithological section provides a general description of the structure of the site.

The characteristics of the physical and mechanical properties of soils should indicate:

granulometric composition of sandy soils;

filtration coefficients of sandy soils and sandy loams;

porosity and fluid loss coefficients;

angle of repose and bearing capacity of soils.

The conclusion must be accompanied by the main geological sections and soil “columns” from the boreholes, necessary for compiling geological sections along the drainage routes.

If necessary, in difficult hydrogeological conditions for drainage projects of blocks and microdistricts, a hydroisohypsum map and a soil distribution map should be attached to the technical conclusion.

In the case of special requirements for the drainage device caused by the specific operating conditions of the protected premises and structures, these requirements must be set forth by the customer as additional source materials for drainage design.

General conditions for choosing a drainage system

The drainage system is selected depending on the nature of the protected object and hydrogeological conditions.

When designing new blocks and microdistricts in areas with high groundwater levels, a general drainage scheme must be developed.

The drainage scheme includes drainage systems that ensure a general decrease in the groundwater level in the territory of the block (neighborhood), and local drainages to protect individual structures from flooding by groundwater.

Drainages that ensure a general decrease in groundwater levels include drainages:

head or shore;

systematic.

Local drainages include drainages:

annular;

wall;

layered.

Local drainages also include drainages designed to protect individual structures:

drainage of underground channels;

pit drainage;

road drainage;

drainage of backfilled rivers, streams, ravines and ravines;

slope and wall drainage;

drainage of underground parts of existing buildings.

Under favorable conditions (in sandy soils, as well as in sandy layers with a large area of their distribution), local drainages can simultaneously contribute to a general decrease in groundwater levels.

In areas where groundwater lies in sandy soils, drainage systems should be used to ensure a general decrease in the groundwater level.

In this case, local drainages should be used to protect individual especially buried structures from flooding with groundwater.

In areas where groundwater lies in clayey, loamy and other soils with low water yield, it is necessary to arrange local drainages.

Local “preventive” drainages should also be installed in the absence of observable groundwater to protect underground structures located in clay and loamy soils.

In areas with a layered aquifer structure, both general drainage systems and local drainages should be installed.

General drainage systems should be installed to drain water-logged sandy layers through which water enters the drained area. In this system, individual local drainages can also be used, in which the radius of the depression curve covers a significant area of the territory. Local drainages must be arranged for underground structures laid in areas where the aquifer is not completely drained by the general drainage system, as well as in places where high water may occur.

Head drainage

To drain areas flooded by a flow of groundwater with a recharge area located outside this territory, head drainage should be installed (see Fig. 3).

The head drainage must be laid along the upper, in relation to the underground flow, border of the drained area. The drainage route is designated taking into account the location of the building and is carried out, if possible, in places with higher water pressure levels.

The head drain should, as a rule, cross the groundwater flow along its entire width.

When the length of the head drainage is less than the width of the underground flow, additional drains should be installed along the lateral boundaries of the drained area in order to intercept groundwater flowing from the side.

If the aquitard is shallow, the head drainage should be laid on the surface of the aquitard (with some penetration into it) in order to completely intercept groundwater, like a perfect type of drainage.

In cases where it is not possible to lay drainage on an aquiclude, and drainage conditions require that the flow of groundwater be completely intercepted, a screen made of a waterproof sheet piling is installed below the drainage, which must be lowered below the aquitard level.

When the aquitard is deep, the head drainage is laid above the aquifer, as an imperfect type of drainage. In this case, it is necessary to calculate the depression curve. If the installation of one head drainage line does not achieve a decrease in the groundwater level to the specified levels, a second drainage line should be laid parallel to the head drainage. The distance between drainages is determined by calculation.

If the part of the aquifer located above the drainage consists of sandy soils with a filtration coefficient of less than 5 m/day, the lower part of the drainage trench must be filled with sand with a filtration coefficient of at least 5 m/day (see Fig. 4).

The height of backfilling with sand is 0.6-0.7H, where: H is the height from the bottom of the drainage trench to the unreduced design groundwater level.

If the part of the aquifer located above the drainage has a layered structure, with alternating layers of sand and loam, backfilling the drainage trench with sand with a filtration coefficient of at least 5 m/day should be done 30 cm above the unreduced design groundwater level.

Backfilling with sand can be done across the entire width of the trench with a vertical or inclined prism, at least 30 cm thick. For head drainage of a perfect type, when the aquifer does not have clay, loamy and sandy loam layers, a sand prism can be installed only on one side of the trench (from the inflow side water).

If the head drainage is laid in the thickness of relatively weakly permeable soils, underlying well-permeable soils, a combined drainage should be installed, consisting of a horizontal drain and vertical self-flowing wells (see Fig. 5).

Vertical wells must be connected by their base to the permeable soils of the aquifer, and by their upper part to the inner layer of the horizontal drain bedding.

To drain coastal areas that are flooded due to the backwater of the water horizon in rivers and reservoirs, coastal drainage should be installed (see Fig. 6), where the designations are: MG - low-water horizon of the reservoir, GPV - horizon of backed-up waters of the reservoir.

Coastal drainage is laid parallel to the shore of the reservoir and laid below the normally supported horizon (NSL) of the reservoir by an amount determined by calculation.

If necessary, head and bank drainages can be used in combination with other drainage systems.

Systematic drainage

In areas where groundwater does not have a clearly defined flow direction, and the aquifer is composed of sandy soils or has a layered structure with open sandy layers, systematic drainage should be arranged (see Fig. 7).

The distance between systematic drainage drains and their depth are determined by calculation.

In urban conditions, systematic drainage can be arranged in combination with local drainage. In this case, when designing individual drains, one should consider the possibility of their simultaneous use as local drainage, protecting individual structures, and as elements of systematic drainage, ensuring a general decrease in the groundwater level in the drained area.

When laying drains for systematic drainage in soil with weak permeability, underlying well-permeable soils, combined drainage should be used, consisting of horizontal drains with vertical, self-flowing wells (see Fig. 5).

In areas flooded by groundwater flows, the recharge area of which also covers the drained area, head and systematic drainage should be used together.

Ring drainage

To protect basements and subfloors of detached buildings or a group of buildings from flooding with groundwater, when they are located in aquiferous sandy soils, ring drains should be installed (see Fig. 8).

Ring drainages should also be installed to protect especially damaged basements in new neighborhoods and microdistricts when the depth of the groundwater level drop is insufficient by the general drainage system of the territory.
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The construction of a drainage system, an integral part of any private house, must be based on the requirements of SNiP: drainage that meets all the rules will be able to fully prevent the negative impact of precipitation and groundwater on buildings and plantings on the site, because this is precisely its obligation.

We will talk about these rules, as well as the features of designing a drainage system, in this article.

Drainage system design

What should the project contain?

The start of drainage installation should be preceded by the development of a system design. The drainage design is created based on engineering hydrological studies of the site. Its purpose is to determine and describe the fundamental technical characteristics of the drainage system.

Typically, the project contains the following data:

schematic representation of the laying of drainage pipes (deep and surface systems);
design parameters of drains - cross-section, slope, assembly of the wellhead part, depth of installation in the ground and distance relative to each other;
standard sizes of drainage system components (drains, wells, connecting elements, etc.);
list of building materials required for installation of the structure.

The project must take into account the following factors:

landscape of the site;
average annual precipitation volume;
composition and characteristics of the soil;
ground water level;
location of nearby natural reservoirs, etc.

What should the estimate include?

Before constructing a drainage system, a local estimates for drainage installation, which consists of the cost of the operations listed below:

dismantling of reinforced concrete foundations;
manually creating trenches 2 m deep in the soil, installing fasteners across the entire width and laying a waterproofing layer of polymer film;
installation of transverse drainage with double-sided outlet;
laying a sewer pipeline from polyethylene pipes;
backfilling the base for crushed stone pipelines;
installation of drainage communications, strengthening of underlying layers and concrete layers (reinforcement);
dismantling of existing asphalt concrete pavements;
creation of new asphalt concrete pavements;
installation of bridges, passages, decking, etc. made of wood;
preparing the soil for crops (filling a layer of soil up to 20 cm thick);
manual sowing of various lawns and other plantings.

To install a drainage system you will need the following materials:

crushed stone;
sand;
corrugated drainage pipes wrapped in geotextile;
geotextiles (needle-punched non-woven fabric used to create an additional filter that may be required depending on the characteristics of the soil at the site);
inspection wells.

Construction of drainage

Rules for arranging drainage

You can protect buildings and plantings from excess moisture by knowing the rules for drainage:

A closed drainage system involves creating a trench in the ground, the depth of which is 70-150 cm and the width is 25-40 cm. A slope directed towards an artificial or natural water intake must be provided. The slope following which drainage systems are installed is described by SNiP as follows:

the slope value is 2 cm per 1 linear m if the soil is clayey;
3 cm per 1 linear m if the soil is sandy.

Option of a drainage system with a slope angle of 2 cm per 1 m (i=0.02)

The bottom of the resulting depression is covered with a cushion of crushed stone. Drains are laid on it, then everything is covered again with crushed stone. Next, the system is backfilled with soil.
Wastewater flows through drainage pipes, collects in a collector and ultimately ends up in a receiving water body (river, ravine, pond, etc.).
Control over the operation of the drainage system is carried out through inspection wells built from reinforced concrete or polymer rings.

Pro tip: If the drainage system is installed correctly, the groundwater level does not rise above the permissible point, but, on the contrary, begins to decline. This leads to increased soil fertility on the site. If the drainage system is not built, the soil may become oversaturated with moisture, which has a negative impact on buildings and crops.

The construction of the drainage system must be made from high-quality, durable materials. Their quality requirements are regulated by the following state standards:

GOST 8411-74. Ceramic drainage pipes. Technical specifications;
GOST 1839-80. Asbestos-cement pipes and couplings for non-pressure pipelines. Technical conditions.

Methodology for constructing a drainage system

Measures for installing a drainage system consist of several stages:

A trench is dug about 70 cm deep and about 50 cm wide. It should be located on a slope, above the house, to collect melted snow and precipitation from the site. Water is discharged outside the territory through drainage pipes.
The bottom of the trench is pre-lined with gravel and it is thoroughly compacted.
Drains are placed on the gravel bed - perforated corrugated pipes with a diameter of 100 mm. In this case, the slope is maintained (2-3 cm per linear meter), and the pipes are wrapped in geotextile - it prevents large particles of soil from getting into the system.

The drainage is covered with a layer of material that allows water to pass through well, for example, expanded clay.
Backfilling with soil is carried out.

As a result, a drainage system is formed on the site, which effectively collects precipitation and meltwater, which otherwise would simply flow down the slope.