The building consists of two different-storey sections, has a rectangular configuration with overall dimensions of 18.0 m × 24.0 m. The height - from the level of the day surface to the level of the roof edge is about 30.5 m. The constructive scheme of the building is frame, with a complete prefabricated reinforced concrete frame, with steel elements. The frame is multi-storey, designed in the transverse direction according to the frame scheme with rigid nodes at the points of junction of crossbars with columns. The foundations for the columns are monolithic reinforced concrete, separate glass type. The foundations of the shop walls are prefabricated reinforced concrete foundation beams.

The building is the year of construction, complex configuration in plan. The building in plan consists of five rectangular sections (two - one-story; three - two-story). The structure of the roof of the building consists of prefabricated slabs with an under-roof space of variable height. The under-roof space is equipped with a natural ventilation system by means of vents. In the natural ventilation system, the cornice vents are made in the form of holes arranged in the cornice part. outer wall. The roof is flat, rolled (bitumen-based isoplast) with an organized internal drain.

The building is of the year of construction, two-story, rectangular in plan, dimensions in the axes 24.0 × 6 0.0 m, height 9.99 m (from the floor level of the 1st floor to the top of the roof). The structural scheme of the building is a frame-braced frame. The frame of the building is made of metal, according to a two-span scheme, with roof trusses. The frames are installed with a step of 6.0 m and combined with roof and wall purlins. Roof trusses are single-pitched, with a span of 12.0 m with a slope of the upper chords from the ridge to the sides at the roof slope. Made of cold-formed thin-walled C- and Z-profiles.

The building is a two-story, square configuration in plan, dimensions in the axes 30.0 × 30.0 m, height 9.13 m (from the floor level of the 1st floor to the top of the roof). A two-storey extension No. 1 (plan dimensions 9.0 × 18.45 m) and a one-story extension No. 2 (plan dimensions 10.86 × 5.06 m) adjoin the building from the north-eastern facade. The structural scheme of the FP building is a steel frame, it consists of one section of the Kislovodsk type with a height of 6.6 m to the bottom of the roof structure, including a structural non-drip slab measuring 27.0 × 27.0 m and four columns located at the corners of a square with a side of 18.0 m. The structural scheme of outbuildings No. 1 and No. 2 is a metal frame. The foundations for the columns and pillars of the half-timbered main frame are columnar from monolithic reinforced concrete on a natural base, shallow.

The building has an elongated, rectangular configuration. Overall dimensions of the building in the plan are 43.10 m × 12.50 m. The height of the building from the level of the day surface to the level of the roof edge is about 6.57 m. b columns with a step of 6 meters with prefabricated reinforced concrete beams (span - 11,400 m) laid on them. The building of the boiler house is a single-span frame building with a hard disk at the level of the floor slabs. The foundations for the columns are columnar monolithic reinforced concrete. Strip foundations internal brick wall - from prefabricated blocks according to GOST 13579-78.

Documents are being prepared for publication.

When performing work on the technical inspection of buildings, one should be guided by the "Safety Rules for Conducting Technical Inspections of Residential Buildings for the Design of Major Repairs" VSN 48-86 (r), as well as the relevant safety requirements when working with instruments and tools.

At technical survey Buildings in the course of a general inspection, you must perform the following tasks:

estimate physical wear and tear structures and engineering systems, buildings in general;


check the condition of structures that have experienced various damages (leaks, floods, fire, etc.);


examine structures that have undergone weakening of design sections during redevelopment of buildings, superstructures of floors, deepening of the basement;


to outline planned and restoration measures (capital and Maintenance building);


identify possible measures for the modernization or reconstruction of the building;


establish the causes of deformations load-bearing structures structures (walls, ceilings, columns);


establish the causes of dampness on the walls and freezing.

Based on the results of the survey, an inspection report, conclusion or report on the technical condition of the structures of the building or structure is drawn up, which contains information obtained from the design and executive documentation, and materials characterizing the features of the operation of structures that necessitated a separate survey. An approximate composition of the technical survey report is given in clause 4.6. VSN 57-88r:

• a list of documentary data on the basis of which the conclusion was drawn up;
  
• a brief technical description of the object with an indication of the purpose, number of storeys, main load-bearing structures, capital group and normative durability of the building;
  
• the historiography of the building;
  
• description of the location of the object;
  
• description general condition buildings according to external inspection;
  
• determination of the physical and moral deterioration of the building as a whole;
  
• description of building structures, their characteristics and condition;
  
• drawings of building structures with details and measurements;
  
• calculation of acting loads and verification calculations of load-bearing structures and foundation foundations;
  
• dimensional plans and sections of the building, plans and sections of pits, wells, drawings of openings;
  
• geological and hydrogeological conditions of the site, construction and permafrost characteristics of the foundation soils (if necessary), operating conditions;
  
• analysis of the causes of the emergency state of the building, if any;
  
• photographs of facades and damaged structures;
  
• conclusions and recommendations.
  

List of documentary data provided by the customer, the report can be combined in tabular form with brief technical description of the object.

The survey begins from the dominant point of the terrain - from the supporting structures that are the first to meet seasonal snow cover, storm drains and groundwater filtering in the same direction. The relief of the area of ​​dense housing development is characterized as calm, pronounced and weakly expressed. When assessing the relief, it should be noted whether there is a tendency for surface runoff to stagnate for a long time on the surveyed site, how the structure itself is located in relation to groundwater filtration routes.

The main purpose of the visual technical inspection report is to give an opinion on the technical condition of the object under study. Depending on the existing defects and damage, the technical condition of individual building structures can be classified into 4 categories according to the general features given in Table. 5.

Overall rating technical condition of load-bearing structures during a preliminary survey of buildings

	General features characterizing the state of the structure
I - normal	There are no visible damage and cracks, indicating a decrease in the bearing capacity of structures. The operating conditions are met in accordance with the requirements of the standards and project documentation. There is no need for repair and restoration work.
II - satisfactory	The load-bearing structures are slightly damaged, in some areas there are separate shells, chips, potholes, hairline cracks. The protective layers of the structures are partially damaged. Ensure normal operating conditions. Current repairs are required, with the elimination of local damage without strengthening the structures.
III - unsatisfactory	There are damages, defects and cracks, indicating a limitation of working capacity and a decrease in the bearing capacity of structures. The requirements of current regulations are violated, but there is no danger of collapse and a threat to safety. Strengthening and restoration of the bearing capacity of structures is required.
	Existing damage indicates the unsuitability of the structure for operation and the danger of its collapse, the danger of people staying in the area of ​​the structures being examined. Urgent measures are required to prevent accidents (installation of temporary support, unloading of structures, etc.). Required overhaul with reinforcement or replacement of damaged structures in general or individual elements.

As can be seen from the presented table. 5, the state of the structure as a whole - depends on the state of the main load-bearing structures. The greatest danger for the spatial rigidity of residential buildings is deformation and destruction in load-bearing structures and elements that have a large specific gravity in the mass of the structure itself: reinforced concrete, stone and reinforced stone, steel.

Assessment of the technical condition of the main load-bearing structures by external signs is based on the definition of:

geometric dimensions of structures and their sections;

state of protective coatings (paint and varnish, plasters, protective screens, etc.);

deflections and deformations of structures.

Technical condition reinforced concrete load-bearing structures evaluated according to the following signs bounce:

unacceptable deviations of compressible reinforced concrete elements from the vertical;

the presence of cracks, spalls and destruction;

deflections and deformations of bent structures;

violation of the adhesion of reinforcement to concrete;

the presence of a rupture of reinforcement;

state of anchoring of longitudinal and transverse reinforcement;

degree of corrosion of concrete and reinforcement.

When determining geometric parameters reinforced concrete structures and their sections, all deviations from their design position are recorded. Reinforced concrete elements working in compression - according to the norms, they can have a deviation from the vertical position of not more than 2 cm by 2 m.

When examining, it should be taken into account that the monolithic reinforced concrete frames of high-rise residential buildings, rented out in Lately, as a rule, have deviations exceeding the normative values ​​by 7-8 times. The rolls of such buildings will only increase in time, since in order to speed up the process construction works, stripping of monolithic reinforced concrete structures is carried out until the concrete reaches 70% strength.

The figure shows a panorama of the collapse monolithic floor the seventh floor during the construction of a multi-storey residential building in Belgorod on February 08, 2011. The ceiling between the sixth and seventh floors also failed, the development of collapse below the sixth floor did not occur. In such cases, it is necessary to unmount the entire frame of the structure, but in practice this does not happen.

Collapse of the monolithic ceiling of the seventh floor of a residential building under construction in Belgorod

Determining the width and depth of crack opening in reinforced concrete structures of operated residential buildings during visual inspection is of decisive importance for ensuring the reliability of the structure as a whole. Cracks are recommended to be measured first of all in places of their maximum opening and at the level of the tensile zone of the element.

The degree of crack opening is compared with the normative requirements for the limit states of the second group, depending on the type and operating conditions of the structures. It is necessary to distinguish between cracks, the appearance of which is caused by stresses manifested in reinforced concrete structures during manufacture, transportation and installation, and cracks caused by operational loads and environmental influences.

To the cracks that appeared in pre-operational period, include: technological, shrinkage cracks caused by rapid drying of the surface layer of concrete and a reduction in volume, as well as cracks from concrete swelling;

cracks caused by uneven cooling of concrete;

cracks that appeared in prefabricated reinforced concrete elements during storage, transportation and installation, in which the structures were subjected to forces from their own weight according to schemes not provided for by the project.

Cracks that appeared during operation include:

cracks resulting from thermal deformations due to violations of the requirements for the installation of expansion joints;

cracks caused by uneven settlement of the soil base, which may be associated with a violation of the requirements for the installation of settlement expansion joints, earthworks in the immediate vicinity of the foundations without providing special measures;

cracks caused by force effects exceeding the bearing capacity of reinforced concrete elements.

Strength cracks must be analyzed from the point of view of the stress-strain state of the reinforced concrete structure.

Thanks to the timely evacuation of residents monolithic house in the Turkish city of Diyabakir, no one was injured. The evacuation was carried out when cracks opened in the stretched zone more than 0.5 mm, a noticeable displacement of the loggia supports, significant deflections of the bending elements.

IN bendable reinforced concrete elements and structures operating according to the beam scheme(beams, girders), cracks appear perpendicular to the (normal) longitudinal axis, due to the appearance of tensile stresses in the zone of action of maximum bending moments and cracks inclined to the longitudinal axis, caused by the main tensile stresses in the zone of action of significant shear forces and bending moments.

Normal cracks have a maximum opening width in the extreme stretched fibers of the element section. Oblique cracks begin to open in the middle part of the side faces of the element - in the zone of maximum tangential stresses, and then develop towards the stretched face.

The formation of inclined cracks at the supporting ends of beams and girders indicates their insufficient bearing capacity along inclined sections. Vertical and inclined cracks in the spans of beams and girders indicate their insufficient bearing capacity in terms of bending moment.

The crushing of concrete in the compressed zone of the sections of the bent elements indicates the exhaustion of the bearing capacity of the structure;

IN reinforced concrete slabs the following cracks occur:

in the middle part of the slab, having a direction across the working span with a maximum opening on the bottom surface of the slab;

on supporting sections having a direction across the working span with a maximum opening on the upper surface of the slab;

radial and end, with the possible falling off of the protective layer and the destruction of the concrete of the slab;

along the reinforcement along the bottom plane of the wall.

Cracks in the supporting sections of the plates across the working span indicate insufficient bearing capacity for the bending support moment.

Assessment of the technical condition of reinforced concrete load-bearing structures according to preliminary survey data

I - normal

There are no visible defects and damage on the concrete surface of unprotected structures, or there are small individual potholes, chips, hairline cracks (no more than 0.1 mm).

Anticorrosion protection of structures and embedded parts has no violations.

The surface of the reinforcement when opened is clean, there is no corrosion of the reinforcement, the depth of concrete neutralization does not exceed half the thickness of the protective layer.

The approximate strength of concrete is not lower than the design one. The color of the concrete has not changed.

The magnitude of the deflections and the width of the cracks do not exceed the allowable according to the standards.

II - satisfactory condition of reinforced concrete structures

Anticorrosive protection of reinforced concrete elements is partially damaged. In some areas, in places with a small amount of the protective layer, traces of corrosion of distribution fittings or clamps appear, corrosion of working fittings with individual points and spots; section loss of working reinforcement no more than 5%; there are no deep ulcers and no rust plates.

Anti-corrosion protection of embedded parts was not found. The depth of concrete neutralization does not exceed the thickness of the protective layer. The color of the concrete has changed due to overdrying, in some places the peeling of the protective layer of concrete during tapping. Peeling of faces and edges of the structure

and subjected to freezing.

The approximate strength of concrete within the protective layer is below the design one, not more than 10%.

The requirements of the current standards relating to the limit states of group I are satisfied; the requirement of standards for limiting states of group II can be partially violated, but normal operating conditions are provided.

III - unsatisfactory condition of reinforced concrete structures

Cracks in the tensile zone of concrete that exceed their allowable opening. Cracks in the compressed zone and in the zone of main tensile stresses, element deflections caused by operational impacts exceed the allowable by more than 30%. Concrete in the tension zone at the depth of the protective layer between the reinforcement bars crumbles easily.

Lamellar rust or ulcers on the rods of bare working reinforcement in the zone of longitudinal cracks or on embedded parts, causing a decrease in the cross-sectional area of ​​​​the rods from 5 to 15%.

Reducing the approximate strength of concrete in the compressed zone of the bending elements up to 30% and in other areas - up to 20%.

Sagging of individual rods of distribution reinforcement, buckling of clamps, rupture of some of them, with the exception of clamps of compressed truss elements due to steel corrosion (in the absence of cracks in this zone).

Reduced against the requirements of the norms and the project, the bearing area of ​​prefabricated elements with a drift coefficient K = 1.6. High water and air permeability of wall panel joints.

IV - pre-emergency or emergency

Cracks in structures experiencing alternating impacts, cracks, including those that cross the support zone of tension reinforcement anchoring; rupture of clamps in the zone of an inclined crack in the middle spans of multi-span beams and slabs, as well as layered rust or pits, causing a decrease in the cross-sectional area of ​​the reinforcement by more than 15%; buckling of reinforcement in the compressed zone of structures; deformation of embedded and connecting elements; waste of anchors from plates of embedded parts due to corrosion of steel in welds, disorder of joints of prefabricated elements with mutual displacement of the latter; displacement of supports; significant (more than 1/50 of the span) deflections of the bent elements in the presence of cracks in the tension zone with an opening of more than 0.5 mm; rupture of clamps of compressed truss elements; rupture of clamps in the zone of an inclined crack; rupture of individual rods of the working reinforcement in the tension zone; crushing of concrete and crumbling of aggregate in the compressed zone.

The decrease in the strength of concrete in the compressed zone of the bending elements and in other areas is more than 30%.

Reduced against the requirements of the norms and the project, the area of ​​\u200b\u200bsupport of prefabricated elements. Existing cracks, deflections and other damage indicate the danger of destruction of structures and the possibility of their collapse

To assign a reinforced concrete structure to the listed categories of condition, it is sufficient to have at least one feature that characterizes this category.

Prestressed reinforced concrete structures with high-strength reinforcement, having signs of condition category II, belong to Category III, and having signs of category III - respectively to category IV, depending on the danger of collapse.

When the bearing area of ​​prefabricated elements is reduced against the requirements of the norms and the project, it is necessary to carry out an approximate calculation of the supporting element for the shear and crushing of concrete. The calculation takes into account the actual loads and strength of concrete.

The assignment of the examined structure to one or another category of state in the presence of signs not noted in the table, in complex and responsible cases, should be made on the basis of an analysis of the stress-strain state of structures performed by specialized organizations.

When examining and assessing the technical condition stone and reinforced masonry structures it is necessary to take into account the features of their work and destruction, due to their structure.

Diagonal cracks associated with openings in brick enclosing structures are the most dangerous confirmation of uneven settlements developing at the base.

Diagonal cracks in masonry with a plaster beacon in place.

Masonry is an inhomogeneous elastic-plastic body consisting of stones and joints filled with mortar. This causes the following features of its work: when the masonry is compressed, the force is transmitted unevenly due to local irregularities and uneven density of individual sections of the hardened mortar. As a result, the stones are subjected not only to compression, but also to bending and shearing.

The nature of the destruction of the masonry and the degree of influence of numerous factors on its strength is explained by the peculiarities of its stress state during compression. Destruction of the ordinary brickwork during compression, it begins with the appearance of individual vertical cracks, as a rule, above and below vertical seams, which is explained by the phenomenon of bending and shearing of the stone, as well as the concentration of tensile stresses above these seams.

When examining stone and reinforced masonry structures, it is necessary first of all to identify the load-bearing elements, the condition of which should be paid attention to. Special attention.

The first cracks in masonry appear at loads less than destructive, and usually the ratio T= N crc/N u the smaller, the weaker the solution ( N crc is the load corresponding to the moment of cracking,

So, for example, for masonry on mortar marks:

50 and up T= 0,7 — 0,8;

10 and 25 T= 0,6 — 0,7;

2 and 4 T= 0,4 — 0,6.

The moment when the first cracks appear depends on the quality of the horizontal joints and the density of the mortar used.

In masonry made of large-sized products (high-hollow ceramic stones, cellular concrete stones), brittle fracture occurs, the first cracks appear at loads of 0.85-1 of the breaking load.

An important reason that reduces the strength and masonry is the uneven density and shrinkage of the solution. Partial filling of vertical joints with mortar does not lead to a decrease in the strength of the masonry, however, it reduces its crack resistance and solidity. Vertical joints and holes in hollow stones break the solidity of the masonry and cause a concentration of tensile and shear stresses at the upper and lower ends of the cracks. Therefore, the strength of masonry from hollow stones is reduced by 15-20% (with the exception of perforated bricks and ceramic stones with slit-like voids).

Assessment of the technical condition of stone structures by external signs

	Signs of the state of structures
I - normal	The design has no visible deformations, damages and defects. The most stressed elements of the masonry do not have vertical cracks and bulges, indicating overstress and loss of structural stability. There is no decrease in the strength of the stone and mortar. The masonry is not wetted. Horizontal waterproofing is not damaged. The design meets the performance requirements.
II - satisfactory	There are minor damage. Hairline cracks crossing no more than two rows of masonry (no more than 15 cm long). Defrosting and weathering of masonry, separation of lining to a depth of up to 15% of the thickness. The bearing capacity is sufficient
III - unsatisfactory	Medium damage. Defrosting and weathering of the masonry, peeling from the lining to a depth of up to 25% of the thickness. Vertical and oblique cracks (regardless of the size of the opening) in several walls and pillars, crossing no more than two rows of masonry. Hairline cracks at the intersection of no more than four rows of masonry with the number of cracks no more than four per 1 m of the width (thickness) of the wall, pillar or partition. The formation of vertical cracks between the longitudinal and transverse walls: breaks or pulling out of individual steel ties and anchors fastening walls to columns and ceilings. Local (marginal) damage to the masonry to a depth of 2 cm under the supports of trusses, beams, girders and lintels in the form of cracks and crevices, vertical cracks at the ends of the supports, crossing no more than two rows. The displacement of floor slabs on supports is not more than 1/5 of the embedment depth, but not more than 2 cm. In some places, wetting of the masonry is observed due to violation of horizontal waterproofing, cornice overhangs, drainpipes. Reducing the bearing capacity of masonry up to 25%. Temporary strengthening of load-bearing structures, installation of additional racks, stops, couplers is required.
IV - pre-emergency or emergency	Strong damage. Deformations, damages and defects are observed in the structures, indicating a decrease in their bearing capacity of up to 50%, but not entailing collapse. Large collapses in the walls. Defrosting and weathering of masonry to a depth of up to 40% of the thickness. Vertical and oblique cracks (excluding temperature and sedimentation) in load-bearing walls and pillars at a height of 4 rows of masonry. Inclinations and buckling of walls within the floor by 1/3 or more of their thickness. The width of the opening of cracks in the masonry from uneven settlement of the building reaches 50 mm or more, the deviation from the vertical is more than 1/50 of the height of the structure. Displacement (shift) of walls, pillars, foundations along horizontal seams or oblique grooves. In the design, there is a decrease in the strength of stones and mortar by 30-50% or the use of low-strength materials. Separation of longitudinal walls from transverse ones at their intersections, ruptures or pulling out of steel ties and anchors that fasten walls to columns and ceilings. In brick vaults and arches, clearly visible characteristic cracks are formed, indicating their overvoltage and emergency condition. Damage to the masonry under the supports of beams and lintels in the form of cracks, crushing of stone or displacement of rows of masonry along horizontal seams to a depth of more than 20 mm. The displacement of floor slabs on supports is more than 1/5 of the embedment depth in the wall.

In case of violation of the horizontal waterproofing, the masonry in this zone is easily disassembled with a crowbar, the stone crumbles, stratifies, when the stone is struck with a hammer, the sound is deaf.

In places of long-term chronic soaking, freezing and weathering of masonry, local destruction of masonry occurs to a depth of 1/5 of the wall thickness or more. It is unacceptable to split the masonry vertically into separate independently working columns, slopes and buckling of walls within the floor by 1/3 of their thickness or more.

When masonry is destroyed from crushing in the support zones of beams and lintels, destruction of individual structures and parts of the building may occur. If deformations and defects are observed in the structures, indicating a loss of their bearing capacity of more than 50%, there is a threat of collapse.

Until recently, in housing construction, the use of steel structures . Metal structures have a low fire resistance limit, they need fire and corrosion protection, so it is assumed that they must be provided with open access for surveys during the entire period of operation. At the same time, metal is the main "cold bridge" in the structure, so its use was limited to unheated industrial buildings with technological regimes that implied a large release of heat.

Recently, metal structures are widely used for the construction of attic floors, not only in the superstructure of reconstructed buildings, but also in the construction of housing.

The photo shows a residential building on the street. L. Tolstoy, Izhevsk. The apartments of the upper floor are made on two levels, the upper level is the attic floor with load-bearing metal structures. In the operational services of the city of Izhevsk, this house received the characteristic name "crying house", because. tenants repeatedly called representatives of operating organizations and designers about unfavorable living conditions in the attic floor.

An inspection of the house showed that the roof had no leaks, as the tenants claimed. Condensed moisture flowed down from the ceiling, since the issues of thermal insulation of metal structures were not resolved during the design. Additional insulation of the attic floor from the inside led to an increase in corrosion damage to the supporting structures. In addition, the designers had incorrectly organized the drain from the roof. Walls of enclosing structures made of silicate bricks are subject to constant waterlogging.

The analysis of survey data of attic floors in operation in the Udmurt Republic, carried out by the specialists of JSC "UDMURTGRAZHDANPROEKT" on calls from residents living in them, made it possible to establish that the wetting of the corners, ceilings and walls of the attic floors was caused not by leaks, but by subsidence condensed water vapor. Moisture condensation occurs for the following reasons:

design flaws:

metal roof structures come into contact with external and internal air, which causes the appearance of cold bridges;


the junction of walls and coverings are solved incorrectly;

Incorrect or careless laying of thermal insulation;

Incorrectly performed heat engineering calculation, which is expressed in an insufficient layer of insulation and the use of inefficient insulation with a large percentage hygroscopicity;

Lack of sufficient air gap between the roofing and insulation;

The absence of a vapor barrier layer along the bottom of the insulation or its damage during construction work;

Lack of cross-ventilation;

The absence of an anti-wind layer on the top of the insulation.

In addition, the residents of the lower floors complained about the avalanche of snow, in connection with which, the results of the survey indicate that the avalanche of snow in winter time called:

The lack of thoughtful snow retention;

The absence of bypass bridges for cleaning the roof from snow;

Insufficient roof slope.

Reconstruction of the hostel on the street. Avant-garde in Izhevsk with an attic floor made of steel structures. The residents went to court twice, because in winter the temperature in the attic floor was +5 0 C. During the reconstruction, the brickwork was wetted and frozen.

During the inspection, roof leaks were also found, which was the result of the use of short-lived roofing material; non-compliance with roofing technology; illiterate solution of complex roof units (valleys; ridges; junctions with walls, outlets of risers, ventilation shafts and channels, radio and television antenna installations). During the operation of the attic floor, the ventilation of the lower floors is disrupted, since the heads of the ventilation shafts turned out to be located in the zone of the aerodynamic shadow (especially with a complex roof structure) of the natural ventilation of the building.

The inefficiency of the operation of the external drain was revealed, which caused icing of drainpipes and the formation of icicles during thaws.

Assessment of the technical condition of steel structures by external signs

Signs of the state of structures
I - normal	There are no signs characterizing the wear of structures and damage to protective coatings
II - satisfactory	The anti-corrosion coating was destroyed in places. In some areas, corrosion in separate spots with a lesion of up to 5% of the cross section, local curvatures from impacts Vehicle and other damage leading to a weakening of the section up to 5%
III - unsatisfactory	The deflections of the bending elements exceed 1/150 of the span. Lamellar rust with a decrease in the cross-sectional area of ​​​​bearing elements up to 15%. Local curvature from vehicle impacts and other mechanical damage, leading to a weakening of the section up to 15%. Curvature of nodal gussets of trusses
IV - pre-emergency or emergency	Deflections of bending elements are more than 1/75 of the span. Loss of local stability of structures (buckling of walls and chords of beams and columns). Shearing individual bolts or rivets in multi-bolt connections. Corrosion with a decrease in the design cross section of the bearing elements up to 25% or more. Cracks in welds or in the near-weld zone. Mechanical damage leading to a weakening of the section up to 25%. Truss deviations from the vertical plane more than 15 mm. Disorder of nodal joints from turning bolts or rivets; ruptures of individual stretched elements; the presence of cracks in the main material of the elements; disorder of joints and mutual displacements of supports. Urgent measures are required to prevent accidents and collapse of structures

At the stage of preliminary inspection of steel structures, recommendations are given on the need to take urgent measures to prevent the accident of structures classified in categories III and IV.

During a preliminary examination of the supporting metal structures, special attention should be paid to columns, frame crossbars, rafter and truss trusses; girders, support points of beams on ledges or consoles, joints of beam joints and their fastenings, for the safety of the protective layer of concrete of reinforced concrete structures in contact with metal embedded parts.

Based on the results of a visual inspection, a preliminary assessment of the technical condition of building structures is made, which is determined by the degree of damage and by the characteristic signs of defects. A fixed picture of defects and damages (for example: in reinforced concrete and stone structures - a diagram of the formation and development of cracks; in wood - places of biodamage; in metal - areas of corrosion damage) can make it possible to identify the causes of their origin and be sufficient to assess the state of structures and draw up a conclusion.

If the results of a visual examination of the supporting structures are insufficient to solve the tasks, then a detailed instrumental examination is carried out. In case of detection of signs indicating the occurrence of an emergency, it is necessary to immediately develop recommendations to prevent a possible collapse. If defects and damages are found that reduce the strength, stability and rigidity of the supporting structures of the structure (columns, beams, arches, floor slabs and ceilings, etc.), a program of work for a detailed survey is additionally developed.

If characteristic cracks, distortions of parts of the building, wall breaks and other damages and deformations are found, indicating an unsatisfactory state of the soil base, it is necessary to conduct an engineering and geological study, the results of which may require not only the restoration and repair of building structures, but also the strengthening of bases and foundations .

The standards do not stipulate the extent to which one or another item of the visual technical inspection report should be submitted. As a rule, this is agreed with the customer and is dictated, first of all, by the purpose of the survey set by him. As an illustration of the individual elements of the report, consider a fragment of reports on the technical inspection of a residential building.

Technical survey report

residential building at the address Izhevsk, st. T. Baramzina, 48

Introduction

Technical inspection of a residential building at st. T. Baramzina, 48 was carried out on the basis of a letter of guarantee from the HOA "Rakurs" in connection with the need

• resuming the system of regular technical inspections and compiling a log of technical inspections;
  
• restoration of the system of planned restoration measures with the issuance of recommendations on the composition of current and major repairs;
  
• drawing up a defective list of missed repair activities to justify statement of claim to the GZhU of Izhevsk on reimbursement of the cost of repair work.
  

The customer did not provide technical documentation facilities located in the GZhU of Izhevsk. serial building, privatized apartments have detailed inventory technical passports, measurement drawings of the building are not required.

The survey was carried out in accordance with the requirements of VSN 57-88r "Regulations on the technical inspection of residential buildings."

Historiography of the building, location of the object

9-storey large-panel residential building of industrial development in the mid-70s. is located on the outskirts of a residential microdistrict bounded by the streets of Tatyana Baramzina, Petrov, Trud, 150 m from the ravine.

The relief is pronounced, superficial and ground water are filtered to the north, towards the ravine. From the influence of the western and southwestern winds prevailing in Izhevsk, the building under investigation is protected by nearby houses.

The surveyed building belongs to the first capital group “Especially capital”, with a standard durability of 150 years. The structure is made of large-block enclosing structures, the floors are reinforced concrete hollow, the coating is rolled.

The surveyed object was put into operation in 1975. The building is in the period of normal operation. Judging by the external examination, the structure was erected without visible signs of errors in design and construction.

The surveyed residential building by now had to go through 5 cycles of current repair measures with a mandatory increase in the moisture resistance of the facades, revision and repair of the joints of the fencing panels, redecoration of the entrances, repair of a flat industrial coating.

In 2000, it was supposed to undergo a complete overhaul as part of the following activities: change of all engineering communications, restoration of the blind area, change of all window and door fillings, reinforcement of balconies and canopies with brick columns.

Instead, in 1997, the roof was repaired, in 2001, the internal water supply and sewerage systems were replaced, a poor-quality repair of the collapsed blind area was made without a roller that diverts water from the edge of the foundation.

In the summer of 2009, during the current repair activities, the following was performed:

- grouting cracks and painting the basement;

— repair of stair railings, replacement of handrails;

– sealing cracks, painting the walls of the staircase;

— painting of window frames;

- whitewashing ceilings.

Thus, it can be concluded that during the period of normal operation, the structure is operated with significant deviations from the regulatory requirements.

Description of the general condition of the building according to external inspection

The assessment of the condition of the structures of the building under investigation was carried out according to VSN 53 “Rules for assessing the physical deterioration of residential buildings”.

The survey was conducted from the dominant point of the relief, along the path of surface runoff and groundwater filtration.

Considering the condition of the blind area, it is safe to say that it does not cope with its purpose, therefore, the basement walls and foundations are constantly moistened.

Walls made of large blocks.

When examining the outer walls, first of all, attention was paid to individual potholes in the textured layer.

Upon closer examination, a deviation of the upper end wall panels was noticed. In addition, weathering of the mortar at the joints was found.

The surface layer of the fencing panels is riddled with horizontal "hairline" cracks.

At the ends of the structure, multiple delaminations of the mortar at the joints, cracks on the outer surface are visible. Inside the building, in the end apartments, traces of leaks in the premises are noticeable. There are cracks, potholes, delamination of the protective layer of concrete along the longitudinal facades, leaks in places and freezing at the joints

Horizontal cracks are observed in the walls, vertical cracks in the lintels, bulging of concrete layers is noticeable, traces of leaks and freezing of panels

Crack width up to 3 mm. Bulging up to 1/200 of the distance between the supporting sections of the panels.

			Partitions of the bearing type. When examining the partitions, cracks up to 5 mm wide and crumbling of the solution at the interface with window frames were found. In general, no damage to the protective layer of the panels and cracks in the panels were found.
		Ceilings from prefabricated slabs.During the construction of the surveyed building, multi-hollow reinforced concrete floor slabs were used. In some rooms, cracks were found at the junction with the walls. There are no cracks in the plates themselves.

Reinforced concrete stairsThe stairs of the building are made of reinforced concrete marches and sites. Stair railings and railings are in good condition.
In some places potholes and chips were found in the steps without the reinforcement being exposed.
Cracks between flights of stairs and sites were sealed in the course of past repair activities.

Protruding elements: balconies and loggias
	When examining the loggias, attention is drawn to the local absence of a plaster layer and significant cracks in the walls with an opening width of up to 1 mm. There are minor damage to the fences of the loggias, numerous shrinkage cracks, as well as damage to the floor and waterproofing. On examination, pronounced corrosion of the metal parts of the balcony railings and significant chips in the slab were noted separately. In addition, the outward slope of the balcony slab is clearly visible. The finishing layer of fences is completely broken.

Flat roof, industrial type, roll roof
Due to the fact that the survey was carried out after the start of the heating season, no coverage was planned. However, the condition of the rolled carpet and the level of compliance with the planned restoration measures by the operating organization can be judged from the condition of the ceiling on the 9th floor of the building, as well as from surveys of residents.

Traces of leaks at the junction of the slabs of the coating to the outer walls	Traces of leaks in the area of ​​​​the passage of storm sewers
Traces of leaks around the hatch

Based on this, we conclude that there is damage to the roofing carpet at the junction with vertical surfaces and small holes throughout the roof, wetting of the insulation layer.

Roof railings are in good condition.

Window frames are wooden. When examining the windows, large cracks were found at the junction of the boxes with the walls. The window sashes were dry and warped. Attention is drawn to the defeat of rot and delamination of wood.	Wooden doors. The doors are in good condition. No damage.

Oil painting.

In the paint layer, local single damage is visible.

The layout in all sections of the surveyed building is convenient for family settlement. The house is equipped with all types of amenities according to the standards (hot water supply, garbage chute, elevator, telephone communications), floors and partitions are non-combustible.

Technical conclusion

The condition of the building is assessed as satisfactory.

— restore inventory documentation;
— restore the log of technical inspections with the system of technical inspections.

foundations

- grouting cracks in the basement;
— filling of seams between blocks;
— repair of plaster walls of the basement;
— repair of vertical and horizontal waterproofing and blind areas.

walls

- sealing potholes, lubrication of the textured layer;
- sealing seams.

load-bearing panel partitions

- sealing cracks, joints with window frames.

floors

- sealing cracks at the junction of plates to the walls.

stairs

- sealing broken places.

loggias

— repair of fences;
- grouting cracks;

balconies

- reinforcement of balconies with brick columns;
— repair of fences;
- replacement of waterproofing with a cement floor device.

roof

- repair of the roof in places;
- repair of water intake devices, cleaning of storm sewers.

window blocks

— complete replacement window blocks.

Due to the fact that all damages are associated with a violation of the requirements of normal operation, it is recommended that the cost of repair measures be presented to the organization that has been collecting housing and communal services from the residents of the surveyed building for 34 years.

Buildings of section No. 1.
The right to carry out this type of work is confirmed by the Certificate of Admission.
The survey was caused by the need to assess the technical condition of the building structures in connection with the existing deformations of the structural elements.
IN project documentation Inspection of building structures included the following types of work:
- performance of measurement work to determine the parameters of the bearing structural elements of the building;
- assessment of the actual technical condition of the main load-bearing structures and the building as a whole;
- issuance of recommendations to ensure the further operational suitability of the building.

Based on the results of a survey conducted in accordance with the requirements
SP 13-102-2003 and GOST 53778-2010, this report has been compiled, which includes:
- drawings of the building (plans, sections, facades);
- the results of the examination of structures (walls, ceilings, coatings, structural elements) with photographic fixation of existing defects;
- conclusions on the assessment of the technical condition of structures;
- recommendations for ensuring the further normal operation of the building.
When performing work, the following documentation was used:
1. Technical passport for the warehouse building.
2. A fragment of a topographic survey of the building site.

2.2. a brief description of object
2.2.1. Total information

The surveyed building is located in Rostov-on-Don.
Climatic conditions:
- Climatic region - III В;
- design winter temperature - 220 С;
- calculated snow load for the II snow region (according to SNiP 2.01.07-85 *) on the horizontal projection of the roof - 1.20 kPa;
- standard wind pressure for the III region (according to SNiP 2.01.07-85 *) at a height of up to 10 m - 0.38 kPa;
- normative depth of soil freezing (according to SNiP 2.02.01-83) - 0.9 m;
- seismicity of the area - 6 points.
Building characteristics:
- level of responsibility of the building - normal;
- degree of durability - II;
- degree of fire resistance of the building - II;
- functional fire hazard class - f 1.1.
Technical and economic indicators:
Total area - 687.8 m2.
Construction volume - 2313 m3.

2.2.2. Conditions for the construction and operation of the building

The warehouse building was built in 1966. There is no information about previous surveys of the building, as well as about the surviving documentation for the construction of the building.
According to the employees who operate the building, several years ago, for a long time, the soils of the base of the foundations were soaked with hot water supply waters (in the area of ​​\u200b\u200baxis "2").
During the survey, it was noted that part of the building in the axes "1" - "2" was attached later than the main building.
In the immediate vicinity of the axis "5" of the surveyed building is located next.
When examining the building, increased humidity and dampness in the basement rooms were noted.

2.2.3. Space-planning and design solutions

The building is a one-story brick building, rectangular in plan, with overall dimensions in the axes 37.3x11.7 m. Under the part of the building in the axes "2/1" - "4" there is a basement 2.4 m high. The height of the first floor is 3.7 ... 3.8 m
The constructive scheme of the building is frameless with load-bearing brick longitudinal walls.
Foundations - tape on a natural basis.
Basement ceiling - reinforced concrete multi-hollow slabs.
Covering - reinforced concrete ribbed and multi-hollow slabs.
The beam on which the floor slabs rest in the axes "1" - "2" is metal.
Lintels over window openings - metal.
The roof is made of rolled welded materials.
Plans, sections and facades are shown on the sheets of the graphic part and in photographs in Appendix 4.1.

2.3. Structural survey

2.3.1. Foundations and engineering-geological conditions

During the inspection of the building, the foundations were not opened and were not studied.
There are no data on engineering-geological surveys. The terrain is calm and flat.

2.3.2. Walls and lintels

Wall and lintel materials
The walls of the building are made of ceramic bricks. The surface of the walls in the premises is plastered. The thickness of the outer and inner walls is 440 mm with a plaster layer. Brick brand M100.
Brick partitions 150…300 mm thick were installed in the basement and first floor rooms.The thickness of the walls of the building does not meet the requirements of heat engineering standards.
Defects in walls and lintels
The main defect of the building walls are vertical, inclined and horizontal sedimentary cracks. The width of the opening of cracks in the walls of the building is up to 15 mm. The maximum deformations are marked in the axes "1" - "3".
Lintels over the openings of the building are made of metal from L75x75 corner and channel)