Types of loads on buildings and structures. Loads and impacts on the building. Structural mechanics Impacts on buildings and structures

A.E.Sutyagin 2017

Buildings (dwelling)- part of human culture. Artificial artifact. Appears with the person. An element of humanizing nature.
The purpose of the building as such is to protect a person, the human body, his health from the influence of nature, from the influence of external natural factors. And also create a suitable habitat regardless of external climatic influences.

Any building consists, first of all, of structures made of one material or another. as well as from various types engineering systems designed for a comfortable environment and meeting the basic physiological needs of people.

Definition of concepts - building and structure.
Building - intended for permanent residence of people.
Construction- not intended for permanent residence of people. Necessary for specific technological tasks.

Components of a building (structure).
Foundation- transfer of load from the entire building to the natural foundation (soil). (“The root of the building”).
Walls- protection from wind and heat influences.
Frame- skeleton of the building.
Floors- perception of load from people, furniture and equipment in the building.
Roof- protection of the building from precipitation (snow, rain), sunlight, thermal influences.

The number of types and types of building parts is so varied and greatly depends on the purpose of the building. In this article, we will focus on the main points.

Building structures are divided into load-bearing and enclosing structures.
Bearing structures- perceive force impacts from other parts of the building and moving loads (people) and transmit them to the base (through foundations). Options load-bearing structures are assigned only on the basis of specialized calculations.
Walling(non-load-bearing) - structures designed to protect people from external factors and ensuring the normal functioning of the building according to the purpose of the building. For example windows and doors.
Enclosing structures are the first to perceive force impacts and transmit them to supporting structures. It is difficult to make a clear gradation between these structures. Typically, in buildings (especially in the past), certain structures can combine the functions of load-bearing and enclosing structures.
For example, brickwork for many centuries - this is both protection from thermal influences and a good load-bearing element.
In industrial buildings they try to separate these functions. (For example, frame and sandwich panels).

Buildings and structures must resist (withstand) the loads and impacts required by regulatory documents.

Article 7 of the Federal Law N 384-FZ " Technical regulations on the safety of buildings and structures" introduces the concept mechanical safety buildings or structures, namely:

“Building structures and the foundation of a building or structure must have such strength and stability that during construction and operation there is no threat of harm to the life or health of people, property of individuals or legal entities, state or municipal property, environment, life and health of animals and plants as a result of:

1) destruction of individual carriers building structures or parts thereof;

2) destruction of the entire building, structure or part thereof;

3) deformation of unacceptable size of building structures, the foundation of a building or structure and geological massifs of the adjacent territory;

4) damage to a part of a building or structure, utility networks or engineering support systems as a result of deformation, movement or loss of stability of load-bearing building structures, including deviations from verticality."

Loads and impacts.

Loads- something that directly exerts force on a structural element. Impacts- something that causes (indirectly) internal forces or deformations in structures.

Loads from the weight of load-bearing and enclosing structures (static)
. Atmospheric loads (dynamic)
.. snowy
..rainy
.. wind (quasi-static and dynamic)
.. icy
.. temperature (exposure)
.. ice
.. wave (storm)
.. magnetic and electromagnetic
and others.
. Impacts of displacements earth's crust
..seismic (tectonic)
.. subsidence (as a result of soil soaking)
.. influence of mining
.. influence of karst-suffusion processes
.. Emergency (special)
.. fire (collapse and thermal impact)
.. collision with a vehicle)
.. explosive
..collapse of parts of the building
.. Loads from rare natural factors
.. hurricanes
.. tornadoes
..tsunami
and etc.

Payloads(what the building is actually designed for)

Loads from the weight of people (“live” load) (quasi-static)
. loads from furniture and household equipment (quasi-static)
. Technological loads (production)
. Weight and dynamic effects of production equipment.
. Crane loads
. Loads from intra-shop transport
. Loads from elevators (etc.).
. Temperature process loads
. High blood pressure(vacuum)
. Technological loads on structures (bridges, cranes, dams, dams, airfields, etc.)

According to the nature of the impact, the loads are divided into
. short-term (repeated or episodic)
. long-term
. permanent

From the point of view: do loads cause dynamic forces in structures.
. static
. quasi-static
. dynamic (pulsating, percussive, periodic, etc.)

Design and operational load value. When designing load-bearing structures for different types calculations use several values ​​of the same load. Least Estimated value(increased) and normative meaning(operational).

Combination of loads. Each load for the calculation of a building element can both load this element and unload this element. Therefore, the calculation uses a certain combination of loads, namely the one that maximally loads the building element being calculated.

It must be understood that the magnitude of the load (both useful and natural) is of a random (“volatile”) nature. IN regulatory documentation the maximum load exceeded is determined, which is unlikely (although possible) during the entire life of the building (70-150 years).

In view of this, for structures higher level responsibility (and, accordingly, a longer service life), increasing coefficients are introduced by which the “basic” load values ​​are multiplied. (reliability coefficient for building liability from 1.1 to 1.2).

For more information about the meaning of certain types of loads, see the list of attached literature.

LITERATURE

1. the federal law dated December 30, 2009 N 384-FZ "Technical regulations on the safety of buildings and structures."

2. GOST 27751-2014 Reliability of building structures and foundations. Basic provisions.

3. SP 20.13330.2016 Loads and impacts. Updated version of SNiP 2.01.07-85.

4. Loads and impacts on buildings and structures. V.N. Gordeev, A.I. Lantukh-Lyashchenko, V.A. Pashinsky, A.V. Perelmuter, S.F. Pichugin; under. general ed.. A.V. Perelmuter. 3rd ed., revised. - M.: Publishing House S, 2009.

In order for a building to be technically feasible, it is necessary to know the external influences perceived by the building as a whole and its separate elements(Fig. 11.2), which can be divided into two types: power(loads) and non-force(environmental influences).

Rice. 11.2.

1 – permanent and temporary vertical force impacts; 2 – wind; 3 – special force impacts (seismic or others); 4 – vibrations; 5 – lateral soil pressure; 6 – soil pressure (resistance); 7 – ground moisture; 8 - noise; 9 – solar radiation; 10 - precipitation; 11 – state of the atmosphere (variable temperature and humidity, presence chemical impurities)

Force influences include different kinds loads:

• constant - from the own mass of the building elements, from the soil pressure on it underground elements;
• temporary long acting– from the weight of stationary equipment, long-term stored cargo, the own weight of partitions that can move during reconstruction;
• short-term - from the mass of moving equipment, people, furniture, snow, from the action of wind on the building;
• special – from seismic impacts, impacts resulting from equipment failure.

Non-force influences include:

• temperature effects affecting the thermal conditions of the premises, as well as leading to temperature deformations, which are already force effects;
• exposure to atmospheric and ground moisture, as well as exposure to moisture vapor in the indoor air, causing changes in the properties of the materials from which the building’s structures are made;
• air movement, causing its penetration into the structure and room, changing their humidity and thermal conditions;
• exposure to direct solar radiation, causing change physical and technical properties surface layers structural material, as well as thermal and light mode premises;
• exposure to aggressive chemical impurities contained in the air, which are mixed with rain or groundwater form acids that destroy materials (corrosion);
• biological effects caused by microorganisms or insects, leading to the destruction of structures and deterioration internal environment premises;
• exposure to sound energy (noise) from sources inside and outside the building, disrupting the normal acoustic conditions in the room.

In accordance with the listed loads and impacts, the following requirements are imposed on buildings and their structures.

• 1. Strength– the ability to withstand loads without destruction.
• 2. Sustainability– the ability of a structure to maintain balance under external and internal loads.
• 3. Rigidity– the ability of structures to bear loads with minimal, advance given standards deformations.
• 4. Durability– the ability of a building and its structures to perform their functions and maintain their qualities during the maximum service life for which they are designed. Durability depends on the following factors:
  • creep of materials, i.e. the process of small continuous deformations occurring in materials under conditions of prolonged exposure to loads;
  • frost resistance of materials, i.e. the ability of wet material to withstand alternate freezing and thawing;
  • moisture resistance of materials, i.e. their ability to withstand the destructive effects of moisture (softening, swelling, warping, delamination, cracking);
  • corrosion resistance, i.e. the ability of materials to resist destruction caused by chemical and electrochemical processes;
  • biostability, i.e. capabilities organic materials resist the destructive effects of insects and microorganisms.

Durability is determined by the maximum service life of buildings. Based on this criterion, buildings and structures are divided into four levels:

• 1st – more than 100 years (main structures, foundations, external walls, etc. are made of materials that are highly resistant to the listed types of influences);
• 2nd – from 50 to 100 years;
• 3rd – from 20 to 50 years (structures do not have sufficient durability, for example houses with wooden external walls);
• 4th – up to 20 years (temporary buildings and structures).

The service life also depends on the conditions in which the building and structure are located, as well as on the quality of their operation.

The most important requirement for buildings and structures is the requirement fire safety. Based on the degree of flammability, building materials are divided into three groups:

• fireproof(do not burn, smolder or char when exposed to fire or high temperature);
• fire-resistant(under the influence of fire or high temperature, they are difficult to ignite, smolder or char, but after removing the source of fire or high temperature, burning and smoldering stop). They are usually protected from the outside with fireproof materials;
• combustible(under the influence of open fire or high temperature they burn, smolder or char and after removing the source of fire or temperature they continue to burn or smolder).

Fire resistance limit building structures are determined by the duration (in minutes) of resistance to fire until loss of strength or stability, or until through cracks form, or until the temperature on the surface of the structure on the side opposite to the fire rises, on average, to more than 140°C.

Buildings or their compartments between fire walls - firewalls (Fig. 11.3), depending on the degree of flammability of their structures, are divided into five degrees of fire resistance. The degree of fire resistance of buildings is determined by Building codes and rules (SNiP) 01/21/97* " Fire safety buildings and structures."

Rice. 11.3. Fire walls - firewalls(A) and zones(b):

1 – fire wall; 2 – fireproof ceiling; 3 – fireproof comb

Fire resistance degree I includes buildings whose load-bearing and enclosing structures are made of stone, concrete, brick using slab or sheet fireproof materials. In buildings of fire resistance class II, the materials are also made of fireproof materials, but have a lower fire resistance limit. In buildings of III degree of fire resistance, the use of combustible materials for partitions and ceilings is allowed. In buildings of IV degree of fire resistance, the use of combustible materials with a minimum fire resistance limit of 15 minutes is allowed for all structures, except for walls stairwells. Fire resistance class V includes temporary buildings. The fire resistance limit of their structures is not standardized. In buildings of III, IV and V degrees of fire resistance, it is envisaged that they will be divided into compartments by firewalls and fireproof ceilings, limiting the area of ​​fire spread.

During construction and during operation, the building experiences various loads. The material of the structure itself resists these forces; internal stresses. Behavior building materials and structures under the influence external forces and loads is studied by structural mechanics.

Some of these forces act on the building continuously and are called permanent loads, others act only at certain periods of time and are called temporary loads.

Constant loads include dead weight of the building, which mainly consists of the weight of the structural elements that compose it load-bearing frame. Self-weight acts constantly in time and in the direction from top to bottom. Naturally, the stress in the material of the supporting structures in the lower part of the building will always be greater than in the upper part. Ultimately, the entire impact of its own weight is transferred to the foundation, and through it to the foundation soil. Its own weight has always been not only constant, but also the main, main load on the building.

Only in last years builders and designers faced completely new problem: not how to securely support a building on the ground, but how to “tie” it, anchor it to the ground so that it is not torn off the ground by other influences, mainly wind forces. This happened because the dead weight of the structures as a result of the use of new high-strength materials and new design diagrams was constantly decreasing, and the dimensions of the buildings were growing. The area affected by the wind, in other words, the windage of the building, increased. And finally, the impact of the wind became more “weighty” than the impact of the weight of the building, and the building began to tend to lift off the ground.

is one of the main temporary loads. As altitude increases, the impact of wind increases. Thus, in the central part of Russia, the wind load (wind speed) at a height of up to 10 m is taken to be equal to 270 Pa, and at a height of 100 m it is already equal to 570 Pa. In mountainous areas and on sea coasts, the impact of wind increases significantly. For example, in some areas of the Arctic and Primorye coastlines, the standard value of wind pressure at a height of up to 10 m is 1 kPa. On the leeward side of the building, a rarefied space occurs, which creates negative pressure - suction, which increases the overall effect of the wind. The wind changes both direction and speed. Strong gusts of wind also create a shock, dynamic effect on the building, which further complicates the conditions for the operation of the structure.

Urban planners faced big surprises when they began to erect buildings in cities high number of storeys. It turned out that the street on which there had never been a breeze strong winds, with the construction of multi-story buildings on it, it became very windy. From a pedestrian’s point of view, wind at a speed of 5 m/s is already becoming annoying: it flutters clothes and ruins hair. If the speed is a little higher, the wind is already raising dust, swirling pieces of paper, and it becomes unpleasant. A tall building is a significant barrier to air movement. Hitting this barrier, the wind breaks into several streams. Some of them go around the building, others rush down, and then near the ground they also go to the corners of the building, where the strongest air currents are observed, 2-3 times higher in speed than the wind that would blow in this place if there were no building. At very tall buildings The force of the wind at the base of the building can reach such proportions that it knocks pedestrians off their feet.

Oscillation amplitude high-rise buildings reaches large sizes, which negatively affects people’s well-being. The creaking and sometimes grinding of the steel frame of one of the tallest buildings in the world, the International Trade Center in New York (its height is 400 m), causes anxiety among people in the building. It is very difficult to foresee and calculate in advance the effect of wind during high-rise construction. Currently, builders are resorting to wind tunnel experiments. Just like aircraft manufacturers! they blow models of future buildings in it and, to some extent, get a real picture of air currents and their strength.

also applies to live loads. Particular attention must be paid to the influence of snow load on buildings of different heights. On the border between the high and low parts of the building, the so-called “ snow bag", where the wind collects whole snowdrifts. At variable temperatures, when the snow alternately thaws and refreezes and at the same time suspended particles from the air (dust, soot) also get here, snow, or more precisely, ice masses become especially heavy and dangerous. Due to the wind, snow cover falls unevenly on both flat and pitched roofs, creating an asymmetric load that causes additional stress in structures.

Temporary refers to (load from people who will be in the building, technological equipment, stored materials, etc.).

Stresses arise in the building and from the impact solar heat and frost. This effect is called temperature-climatic. Warming up sun rays, building structures increase their volume and size. Cooling during frosts, they decrease in volume. With such “breathing” of a building, stresses arise in its structures. If the building has great length, these stresses can reach high values ​​exceeding permissible values, and the building will begin to collapse.

Similar stresses in the structural material arise when uneven settlement of the building, which can occur not only due to different bearing capacity reasons, but also because big difference in the payload or dead weight of individual parts of the building. For example, a building has a multi-story and a single-story part. In the multi-storey part, on the floors there is heavy equipment. The pressure on the ground from the foundations of a multi-story part will be much greater than from the foundations of a single-story part, which can cause uneven settlement of the building. To relieve additional stress from sedimentation and temperature effects, the building is “cut” into separate compartments using expansion joints.

If a building is protected from temperature deformations, then the joint is called a temperature joint. It separates the structures of one part of the building from another, with the exception of the foundations, since the foundations, being in the ground, do not experience temperature effects. Thus, expansion joint localizes additional stresses within one compartment, preventing their transfer to adjacent compartments, thereby preventing their addition and increase.

If the building is protected from sedimentary deformations, then the seam is called sedimentary. It separates one part of the building from another completely, including the foundations, which, thanks to such a seam, are able to move one in relation to another in vertical plane. Without seams, cracks could appear in unexpected places and compromise the strength of the building.

In addition to permanent and temporary, there are also special impacts on buildings. These include:

• seismic loads from an earthquake;
• explosive effects;
• loads arising from accidents or breakdowns of technological equipment;
• impacts from uneven deformations of the base during soaking of subsidence soils, during thawing of permafrost soils, in mining areas and during karst phenomena.

According to the place where the forces are applied, loads are divided into concentrated (for example, the weight of equipment) and uniformly distributed (its own weight, snow, etc.).

By the nature of the action, loads can be static, i.e., constant in value over time, for example, the same dead weight of structures, and dynamic (shock), for example, gusts of wind or impact moving parts equipment (hammers, motors, etc.).

Thus, the building is subject to a variety of loads in terms of magnitude, direction, nature of action and location of application (Fig. 5). A combination of loads may result in which they will all act in the same direction, reinforcing each other.

Rice. 5. Loads and impacts on the building: 1 - wind; 2 - solar radiation; 3 - precipitation (rain, snow); 4 - atmospheric influences (temperature, humidity, chemicals); 5 - payload and dead weight; 6 - special impacts; 7 - vibration; 8 - moisture; 9 - soil pressure; 10 - noise

It is these unfavorable combinations of loads that building structures are designed to withstand. The standard values ​​of all forces acting on the building are given in SNiP. It should be remembered that impacts on structures begin from the moment of their manufacture and continue during transportation, during the construction of the building and its operation.

Blagoveshchensky F.A., Bukina E.F. Architectural designs. - M., 1985.

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION

FSBEI HPE "BASHKIR STATE UNIVERSITY"

INSTITUTE OF MANAGEMENT AND ENTREPRENEURSHIP SECURITY

Department of Economics, Management and Finance

TEST

By subject: Maintenance buildings and structures

Topic: Types of impact on buildings and structures

Completed by: student of group EUKZO-01-09

Shagimardanova L.M.

Checked by: Fedotov Yu.D.

Introduction

Load classification

Load combinations

Conclusion

Introduction

When constructing buildings and structures near or close to existing ones, additional deformations of previously constructed buildings and structures occur.

Experience shows neglect special conditions such construction can lead to the appearance of cracks in the walls of previously constructed buildings, distortions of openings and flights of stairs, to the displacement of floor slabs, destruction of building structures, i.e. to disruption of the normal operation of buildings, and sometimes even to accidents.

When new construction is planned on a built-up area, the customer and the general designer, with the involvement of interested organizations operating the surrounding buildings, must resolve the issue of inspecting these buildings in the zone of influence of the new construction.

A nearby building is considered to be an existing building located in the zone of influence of settlement of the foundations of a new building or in the zone of influence of work on the construction of a new building on the deformation of the base and structures of the existing one. The zone of influence is determined during the design process.

Load classification

Depending on the duration of the load, one should distinguish between permanent and temporary (long-term, short-term, special) loads. Loads arising during the manufacture, storage and transportation of structures, as well as during the construction of structures, should be taken into account in calculations as short-term loads.

a) the weight of parts of structures, including the weight of load-bearing and enclosing building structures;

b) weight and pressure of soils (embankments, backfills), rock pressure.

The forces from prestressing remaining in the structure or foundation should be taken into account in calculations as forces from permanent loads.

a) the weight of temporary partitions, grouting and footings for equipment;

b) the weight of stationary equipment: machines, apparatus, motors, containers, pipelines with fittings, supporting parts and insulation, belt conveyors, permanent lifting machines with their ropes and guides, as well as the weight of liquids and solids filling equipment;

c) the pressure of gases, liquids and granular bodies in containers and pipelines, overpressure and air rarefaction that occurs during ventilation of mines;

d) loads on floors from stored materials and shelving equipment in warehouses, refrigerators, granaries, book depositories, archives and similar premises;

e) temperature technological influences from stationary equipment;

f) the weight of the water layer on water-filled flat surfaces;

g) the weight of industrial dust deposits, if its accumulation is not excluded by appropriate measures;

h) loads from people, animals, equipment on the floors of residential, public and agricultural buildings with reduced standard values.

i) vertical loads from overhead and overhead cranes with a reduced standard value, determined by multiplying the full standard value of the vertical load from one crane in each span of the building by the coefficient: 0.5 - for groups of operating modes of cranes 4K-6K; 0.6 - for the 7K crane operating mode group; 0.7 - for the 8K crane operating mode group. Groups of crane operating modes are accepted according to GOST 25546-82;

j) snow loads with a reduced design value, determined by multiplying the full design value by a factor of 0.5.

k) temperature climatic influences with reduced standard values, determined in accordance with the instructions of paragraphs. 8.2-8.6 under the condition q1 = q2 = q3 = q4 = q5 = 0, DI = DVII = 0;

m) impacts caused by deformations of the base, not accompanied by a fundamental change in the structure of the soil, as well as thawing of permafrost soils;

m) impacts caused by changes in humidity, shrinkage and creep of materials.

In areas with average temperature January minus 5°C and above (according to map 5 of Appendix 5 to SNiP 2.01.07-85*) snow loads with a reduced calculated value are not established.

a) loads from equipment arising in start-up, transition and test modes, as well as during its rearrangement or replacement;

b) the weight of people, repair materials in equipment maintenance and repair areas;

c) loads from people, animals, equipment on the floors of residential, public and agricultural buildings with full standard values, except for the loads specified in clause 1.7, a, b, d, e;

d) loads from mobile lifting and transport equipment (forklifts, electric vehicles, stacker cranes, hoists, as well as from overhead and overhead cranes with full standard values);

e) snow loads with full calculated value;

f) temperature climatic effects with full standard value;

g) wind loads;

h) ice loads.

a) seismic impacts;

b) explosive effects;

c) loads caused by sudden disturbances technological process, temporary malfunction or breakdown of equipment;

d) impacts caused by deformations of the base, accompanied by a radical change in the structure of the soil (when soaking subsidence soils) or its subsidence in mining areas and karst areas.

Load combinations

Calculation of structures and foundations according to limit states The first and second groups should be performed taking into account unfavorable combinations of loads or corresponding efforts.

These combinations are established from the analysis real options simultaneous action of various loads for the considered stage of operation of the structure or foundation.

Depending on the load composition taken into account, a distinction should be made between:

a) the main combinations of loads, consisting of permanent, long-term and short-term,

b) special combinations of loads, consisting of permanent, long-term, short-term and one of the special loads.

Live loads with two standard values ​​should be included in combinations as long-term - when taking into account the reduced standard value, as short-term - when taking into account the full standard value.

In special combinations of loads, including explosive effects or loads caused by collisions of vehicles with parts of structures, it is possible not to take into account the short-term loads specified in clause 1.8.

When taking into account combinations that include permanent and at least two live loads, the calculated values ​​of live loads or the corresponding forces should be multiplied by combination coefficients equal to:

in basic combinations for long-term loads y1 = 0.95; for short-term y2 = 0.9:

in special combinations for long-term loads y1 = 0.95; for short-term y2 = 0.8, except for cases specified in the design standards for structures for seismic areas and in other standards for the design of structures and foundations. In this case, the special load should be taken without reduction.

In the main combinations, when taking into account three or more short-term loads, their calculated values ​​can be multiplied by the combination factor y2, taken for the first (according to the degree of influence) short-term load - 1.0, for the second - 0.8, for the rest - 0.6.

When taking into account load combinations, one temporary load should be taken into account:

a) a load of a certain kind from one source (pressure or vacuum in a container, snow, wind, ice loads, temperature climatic influences, load from one loader, electric vehicle, overhead or overhead crane);

b) load from several sources, if they joint action taken into account in the standard and design load values ​​(load from equipment, people and stored materials on one or more floors, taking into account the coefficients yA and yn; load from several overhead or overhead cranes, taking into account the coefficient y; ice-wind load

Methods for combating impacts on buildings and structures

When designing engineering protection against landslide and landslide processes, the feasibility of using the following measures and structures aimed at preventing and stabilizing these processes should be considered:

changing the topography of the slope in order to increase its stability;

flow regulation surface waters using vertical layout of the territory, system design surface drainage, prevention of water infiltration into the soil and erosion processes;

artificially lowering the groundwater level;

agroforestry;

soil consolidation;

retaining structures;

Retaining structures should be provided to prevent shifting, collapse, landslides and soil dumps if it is impossible or economically unfeasible to change the topography of the slope (slope).

Retaining structures are used in the following types:

supporting walls - to strengthen overhanging rock cornices;

buttresses - individual supports embedded in stable layers of soil to support individual rock masses;

girdles - massive structures for supporting unstable slopes;

facing walls - to protect soil from weathering and crumbling;

fillings (sealing voids formed as a result of fallouts on slopes) - for protection rocky soils from weathering and further destruction;

anchor fastenings - as an independent retaining structure (with base plates, beams, etc.) in the form of fastening individual rock blocks to a solid mass on rocky slopes (slopes).

Snow retention structures should be placed in the avalanche zone in continuous or sectional rows to the lateral boundaries of the avalanche catchment area. The top row of structures should be installed at a distance of no more than 15 m down the slope from the highest position of the avalanche line (or from the line of snow-blowing fences or kolktafels). Rows of snow-retaining structures should be positioned perpendicular to the direction of snow cover sliding.

Avalanche braking structures should be designed to reduce or completely dampen the speed of avalanches on alluvial fans in the avalanche deposition zone where the slope is less than 23° steep. In some cases, when the protected object is in the zone of avalanche initiation and the avalanche has a short acceleration path, it is possible to locate avalanche braking structures on slopes steeper than 23°.

Conclusion

For selection optimal option engineering protection, technical and technological solutions and measures must be justified and contain assessments of the economic, social and environmental effects when implementing the option or abandoning it.

Options are subject to justification and evaluation technical solutions and activities, their order, timing of implementation, as well as maintenance regulations created systems and protective complexes.

Calculations associated with relevant justifications must be based on source materials of equal accuracy, detail and reliability, on a single regulatory framework, the same degree of elaboration of options, an identical range of costs and results taken into account. Comparison of options when there are differences in the results of their implementation should take into account the costs necessary to bring the options to a comparable form.

When determining the economic effect of engineering protection, the amount of damage must include losses from exposure to hazardous geological processes and the costs of compensating for the consequences of these impacts. Losses for individual objects are determined by the value of fixed assets on an average annual basis, and for territories - on the basis specific losses and the area of ​​the threatened territory, taking into account the duration of the period of biological restoration and the period of implementation of engineering protection.

The prevented damage must be summed up across all territories and structures, regardless of the boundaries of the administrative-territorial division.

List of used literature

1.V.P. Ananyev, A.D. Potapov Engineering geology. M: Higher. Shk. 2010

2.S.B. Ukhov, V.V. Semenov, S.N. Chernyshev Soil mechanics, foundations, foundations. M: High. Shk. 2009

.IN AND. Temchenko, A. A Lapidus, O.N. Terentyev Technology construction processes M: High. Shk. 2008

.IN AND. Telichenko, A.A. Lapidus, O.M. Terentyev, V.V. Sokolovsky Technology of construction of buildings and structures M: Vys. Shk. 2010

.SNiP 2.01.15-90 Engineering protection of territories, buildings and structures from hazardous geological loads.

During the design, it is necessary to take into account everything that the building must resist in order not to lose its performance and strength qualities. Loads are considered to be external mechanical forces acting on a building, and impacts are internal phenomena. To clarify the issue, let us classify all loads and impacts according to the following criteria.

By duration of action:

• constant - the own weight of the structure, the mass and pressure of the soil in embankments or backfills;
• long-term - mass of equipment, partitions, furniture, people, snow load, this also includes impacts caused by shrinkage and creep of building materials;
• short-term - temperature, wind and ice climatic influences, as well as those associated with changes in humidity, solar radiation;
• special - standardized loads and impacts (for example, seismic, fire, etc.).

Among designers there is also the term payload, the meaning of which is regulatory documents not fixed, but the term exists in construction practice. By useful load we mean the sum of some temporary loads that are always present in a building: people, furniture, equipment. For example, for a residential building it is 150...200 kg/m2 (1.5...2 MPa), and for an office building - 300...600 kg/m2 (3...6 MPa).

By nature of work:

• static - own weight of the structure, snow cover, equipment;
• dynamic - vibration, gust of wind.

According to the place where the effort is applied:

• concentrated - equipment, furniture;
• evenly distributed - the mass of the structure, the snow cover.

By the nature of the impact:

• force loads (mechanical) are loads that cause reactive forces; all the above examples apply to these loads;
• non-force impacts:
• changes in outside air temperatures, which causes linear temperature deformations of building structures;
• flows of vaporous moisture from premises - affect the material of external fences;
• atmospheric and ground moisture, chemically aggressive environmental influences;
• solar radiation;
• electromagnetic radiation, noise, etc., affecting human health.

All power loads are included in engineering calculations. The influence of non-force impacts is also necessarily taken into account during design. Let's see, for example, how temperature effects affect the structure. The fact is that under the influence of temperature, the structure tends to shrink or expand, i.e. change in size. This is prevented by other structures with which this structure is associated. Consequently, in those places where structures interact, reactive forces arise that need to be absorbed. Also in long buildings it is necessary to provide gaps.

Other influences are also subject to calculations: calculations for vapor permeability, thermotechnical calculation etc.