Type of rubble formed during the complete destruction of buildings. Restoration of tunnels. Causes of blockages

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Causes and types of tunnel destruction

Destruction of tunnels can occur during construction or operation.

IN during the construction process the causes of destruction and collapses are either an incorrect assessment and insufficient knowledge of the engineering and geological conditions of the location of the tunnels, or the choice of incorrect methods for the construction of the tunnel or their low quality. The hydrogeological features of the massif that contribute to the occurrence of destruction and landslides include: the presence of weak water-bearing and water-saturated soils such as quicksand; inclined and horizontal bedding of soils and the presence of sliding planes in them in the form of wetted thin clay layers; the presence of fault, landslide and landslide areas, as well as karst formations in the tunnel area; severe cracking of soils.

The most characteristic construction defects causing emergency situations in tunnel workings are: untimely installation of temporary support; prolonged idle time on temporary supports for certain sections of a long-distance tunnel; installation of supports of insufficient load-bearing capacity; deviation from approved projects; low quality of work.

IN destruction of tunnels during operation may occur either due to inconsistency of the lining design current loads, or as a result of deliberate destruction. Inconsistency of the structure with the current loads most often leads to gradual damage and increased deformation of the lining. In this case, it is usually possible to prevent destruction and collapses in the tunnel through appropriate measures. However, in the practice of operating tunnels, there are still cases of major destruction, the main reasons for which are: non-compliance with accepted constructive solutions actual hydrogeological conditions; deviations during the construction process from the adopted design decisions; increase in rock pressure; the formation of voids behind the lining and collapses of the mountain range as a result of the influence of groundwater; chemical and thermal effects of locomotives, which enhance weathering processes and create preconditions for collapses in unlined tunnels; sudden shifts and landslides due to the instability of the tunnel mass; impact of seismic forces on the tunnel.

Caused by the above reasons, the destruction of the tunnel along its length can be general or local. Usually you have to deal with the destruction of individual areas located near portals or inside a tunnel. The degree of destruction of the structure, in turn, can be complete or partial.

A pile of collapsed rock, lining fragments and equipment and structures buried in them, completely or partially filling a tunnel section, is called a blockage. Depending on the nature of the spread of the collapse and its size There are the following types of blockages:

• open rubble(collapse without separation), in which the collapse zone reaches the surface of the earth (Fig. 8.14, a);
• closed blind dam(blind blockage with separation), in which a collapse arch is formed above the tunnel, and the rock fills the entire transverse profile of the tunnel (Fig. 8.14, b);
• closed blockage(blockage with separation), in which a collapse arch is formed above the tunnel with partial filling of the transverse profile of the tunnel with rock (Fig. 8.14, c);
• closed blockage transitional type , when on one side it looks like a blind blockage, and on the other side, the transverse profile of the tunnel is partially filled with rock (Fig. 8.14, d).

Rice. 8.14 - Main types of rubble

The arch of the shaft or the so-called “dome” may have different shape and the degree of stability, depending on the engineering and geological conditions and the reasons that caused the destruction of the tunnel. Sometimes a collapse after covering individual overhanging pieces of rock does not threaten further collapse. Much more often, a temporary stabilization of a fall occurs with its subsequent development due to the collapse of the soil in some places in the form of small or large pieces and even blocks with a volume of up to 1.0-1.5 m 3. In soft soils, with the formation of closed rubble, unstable stabilization of the rockfall occurs, which threatens further collapse of large masses of soil and even its transition to an open rubble. All this poses a great danger when restoring such tunnels.

Stages of restoration work

Restoration of the destroyed section or the entire tunnel can begin only after an appropriate survey has been carried out. The objective of the technical survey is to collect the necessary data for the correct determination of a rational restoration option, its successful implementation and subsequent operation of the tunnel.

In the case of restoration of destruction that occurred during the construction process, using the design estimates and other documents available for construction, it is possible to comprehensively establish the hydrogeological characteristics of the massif, analyze the organization and order of work, identify the causes of destruction and select the most rational restoration option. First of all, under all circumstances, measures should be taken to stabilize the collapse that has occurred. prevent its further spread. To do this, it is necessary to strengthen the support of nearby sections of the tunnel, build jumpers when quicksand penetrates into the tunnel, etc. It should also be borne in mind that the project for organizing work to restore the destroyed section must be drawn up in such a way that, simultaneously with the elimination of the consequences of the accident, it is possible would resume work on further construction of the tunnel. For this purpose, additional bypass adits, shafts or other auxiliary workings can be made.

When restoring damage that occurred in exploited tunnels, the necessary technical documentation may be missing. Then, along with collecting general information about engineering-geological conditions of time and method of tunnel construction and other data special attention attention should be paid to studying the destroyed section of the tunnel. It is necessary to clarify the physical-mechanical and engineering-geological characteristics of the soil in the rubble, the stability of the new state of rock equilibrium and the expected rock pressure, the nature and size of the destruction, the condition of the lining and its size both in the destroyed and in the adjacent section of the tunnel. Based on the surveys carried out, the most rational option for restoring the tunnel is selected, and the sequence and phasing of work is determined.

Complete restoration of the tunnel, eliminating all consequences of destruction and bringing it to a condition that would satisfy modern conditions operation requires significant investment of time and money. However, due to the need to urgently open traffic on this section of the line, the time spent on restoration should be minimal, so the restoration of tunnels can be carried out under certain conditions in two stages.

Temporary recoverytunnels produced according to simplified technical conditions. At this first stage of work, the tunnel is cleared at the site of the blockage, the section is secured with temporary reliable support (Fig. 8.15) according to the established dimensions and the superstructure of the track is laid. When restoring single-track tunnels, the internal outline of the temporary lining is usually taken to coincide with the external outline of the destroyed tunnel lining, which allows the next stage of restoration work to be limited to only the construction of a permanent lining, without resorting to work to expand the tunnel opening. In areas where the lining is partially destroyed, metal circles can be used as temporary load-bearing structures. Temporary restoration of double-track tunnels is usually carried out under one track with excavation in the area of ​​the blockage of a working of limited profile.

Rice. 8.15 - Temporary lining of metal three-hinged arches: 1 - wooden beams; 2 - anchored bolt; 3 - metal supporting arch

Major restoration must ensure conditions for constant normal operation of the structure and be carried out in accordance with current standards and technical conditions. Major restoration without an intermediate stage of work is advisable only if the timing and scope of work differ little from those required for temporary restoration.

Temporary recovery

The choice of one or another method of eliminating rubble depends mainly on its type, as well as the degree of soil stability.

Elimination of open rubble, in which the collapse zone reaches the ground surface, is carried out using one of the following methods. The use of one method or another is determined by the nature of the tunnel destruction.

On the rubble site Only the vault was destroyed, but the walls were preserved. In this case, they first pass through the upper adit in a section up to 6 m long and open the calotte. Then install metal bearing circles (2) (Fig. 8.16) and remove the blockage with ledges.

Rice. 8.16 - Scheme of installation of support on initial stage restoration of a single-track tunnel: 1 - safety circles; 2 - metal load-bearing circles; 3 - blockage; 4 - marchevans (puff); 5 - runs; 6 - spacer

On the site the obstruction lining is completely destroyed or has not yet been erected. In this case, work also begins with driving the upper adit and opening the calotte, but then developing a profile for the walls in the trenches. Next, metal bearing circles (3) (Fig. 8.17) are installed along the outer contour of the excavation or a permanent lining is erected. The work is completed by developing the core and restoring the upper structure of the track. This type of blockage can also be eliminated using the support core method with the installation of a temporary metal lining of circular arches with plank cladding or the construction of a permanent lining.

Rice. 8.17 - Scheme for developing a tunnel profile when the entire lining is destroyed: 1 - longarins; 2 - pillars; 3 - metal load-bearing circles

Happened in the tunnel breaking through a large amount of water-saturated soil. Restoration work in this case is carried out using special methods using compressed air, freezing or another method of artificially fixing soils. The question may even arise about the advisability of bypassing the breakthrough zone or even changing the route of the entire tunnel.

Elimination of closed rubble carried out depending on the height of the fall and the degree of its stability. Restoration can be carried out without first laying the “dome” or with its first securing.

Restoration work without preliminary laying the “dome” carried out if the shaft arch is in a stable state. Work is then carried out using one of the following methods.

Debris clearing without protective devices is carried out in hard soils with stable stabilization of the natural arch of the ruin. Before clearing the rubble, a thorough ruffle of the “dome” is done. During temporary restoration, the lining is not restored, and the surface of the fallout is sometimes secured with shotcrete.

Clearing the rubble under the protection of a mobile structure is advisable when individual small bushes of soil may fall. In the tail part, the structure rests on the installed and backfilled frames (1) (Fig. 8.18) of the temporary lining, and in the head part - on the blockage (4). The protective structure is moved using a winch.

Rice. 8.18 - Scheme of restoration of the area under the protection of a mobile structure: 1 - temporary fastening frames; 2 - backfill; 3 - protective visor; 4 - blockage

Working with a movable tent can be used when clearing large volumes of rubble that require the use of high-performance machines and equipment. The movable tent is a frame metal structure that moves on special trolleys with shock absorbers (Fig. 8.19). The tent has a head canopy (8), under the protection of which the rubble is dismantled using a rock-loading machine (1), and a lifting tail part (7) to protect workers when constructing the lining and laying the rockfall. The presence of telescopic poles at the tent allows it to be passed in a lowered state within the undamaged sections of the tunnel.

Rice. 8.19 - Diagram of a movable tent in working position: 1 - rock loading machine; 2 - trolley; 3 - temporary wooden support on metal arches; 4 - preserved lining; 5 - dumping tab; 6 - shaft mounting; 7 - lifting tail part of the tent; 8 - head visor

Restoration work with priority filling of the fallout or securing the “dome” are carried out if the shaft arch is in a state of unstable stabilization.

The “dome” is laid from the surface with crushed soil through specially excavated exploration shafts (Fig. 8.20) or drilled wells. If the tunnel is deep, digging special shafts to lower soil from the surface may not be practical. Wells can be drilled to a depth of 100 m or more.

Rice. 8.20 - Exploration mine

Securing the fallout and laying the “dome” from the tunnel is carried out at a small height of the fallout using a system of longitudinal and cross beams, racks and struts (Fig. 8.21). The support system is determined by the outline of the “dome”. To give it greater stability, the space between the posts and struts can be filled with soil. After securing the fallout and filling the “dome,” the tunnel is restored in the same way as was done in the case of open rubble.

Major restoration of tunnels

Major restoration of tunnels, provides for the complete elimination of the consequences of destruction and ensuring normal conditions its operation.

Rice. 8.21 - Scheme for securing the fallout and laying the dome

When constructing linings, it should be taken into account that the soil in the rubble cannot fully resist the movements of the lining. In such cases, it is necessary to erect reinforced linings, where the installation of a reverse vault is of particular importance.

If there is free space for the construction of the lining, provided for by temporary restoration, the work is carried out simply. The lining is then constructed using metal movable prefabricated formwork or circles (Fig. 8.22).

Rice. 8.22 - Scheme of lining construction during major restoration of the tunnel: on the left - installation of formwork; on the right - concreting the lining; 1 - bearing circling temporary restoration; 2 - tightening of temporary restoration; 3 - metal supporting circles; 4 - formwork boards; 5 - backfill

When falling out high altitude, in which during temporary restoration the backfill was not completed completely and the temporary lining was erected along a limited profile or in double-track tunnels temporarily restored for single-track traffic, the task of capital restoration is much more difficult due to a large number re-fastenings that must be performed when installing the formwork (1) (Fig. 8.23).

Rice. 8.23 - Scheme of the capital restoration of a double-track tunnel, temporarily restored to a single-track one: on the left - formwork installation; on the right - concreting the lining; 1 - formwork; 2 - roof lining; 3 - temporary restoration arches

It is advisable to secure the roof of the dump with the help of capital structures above the lining, resting on the lining (Fig. 8.24).

Rice. 8.24 - Types of superstructure capital structures for supporting the roof of the dump: a - ribbed ceiling on the transverse walls; b - ribbed ceiling on racks; c - the same on the longitudinal walls; g - separate vault; 1 - reinforced concrete transverse wall; 2 - layer of shot concrete; 3 - passage; 4 - lining; 5 - racks; 6 - reinforced concrete longitudinal walls; 7 - concrete vault

The elimination of open and closed rubble during capital restoration is carried out in almost the same way as during temporary restoration, but during the work process a permanent lining is immediately erected.

One of my clients has a greenhouse in her house in the Gifts of Fortune zone. She used to take all her unnecessary things there.

This lady was an excellent doctor, but could not earn enough money to support herself. By cleaning out the greenhouse and planting flowers in it, she saw her income increase significantly.

Another woman has accumulated a lot of junk in the Relationship area. All the men she attracted in her life were burdened with problems. Having cleared this area of ​​debris, she finally found a man with whom she was able to establish a strong relationship.

If there are probably weak ones in your life sides, check if the corresponding area in your home is not littered with all sorts of rubbish!

Your front entrance

Keep this area completely clean. The front entrance to your home symbolizes your approach to the world, looking outward, and your approach to your own life, looking inward.

When the first thing you see when entering your home is a pile of trash, your energy level drops before you even cross the threshold. Some people like to hang all their outerwear and put their shoes in a tiny space outside the entrance of course the door(see source) . This is definitely not a good idea.

Others like to put things near the entrance so as not to forget to take them out of the house, and this ends up with them having to constantly step over the resulting rubble. This is how you create tension for yourself.

An amazing number of people care about environment, use the front area of ​​their home as a place to store old newspapers, magazines, cans and plastic bottles, which are then handed over for recycling.

By keeping all this in sight, you are making a statement (no matter how unconscious it may be) that your approach to life is to constantly repeat situations of the past.

This can relate to ideas, problems, illnesses, relationships with people and so on. This means you never learn a lesson the first time. Repetition in itself is not a bad thing. However, why admire this rubbish without even crossing the threshold of your home?

Behind the doors

Doors that don't open all the way restrict the flow of energy in your life. I have been in houses where so much rubbish accumulated behind the doors that people had to squeeze through narrow cracks. Remove anything that prevents the doors from opening fully, including clothing hanging behind them.

Corridors

These are the arteries of your home. Clutter in the hallway and corridors interferes with the flow of life energy and puts obstacles in your path. As a result, you are more likely to trudge through life like an old nag than to enjoy a walk. Keep all aisles clear.

If you can't avoid clutter, at least remove debris from the floor. Many people suffering from depression keep all sorts of nasty things on the floor, which constantly(source not specified) “grounds” their energy.

Under the beds

Piles of junk under your bed are affecting the quality of your sleep. If you sleep on a bed with drawers, then it is best to keep only clean bed sheets. To sleep well, remove everything from your bedroom except the bed itself!

On cabinets

Debris hidden from view on cabinets is like problems hanging over you, awaiting a solution. They reduce your ability to think clearly and clearly. If you stack things on top of your bedroom closet, it probably has an impact. influence(source not specified) on your dream.

You'll have a hard time waking up if the first thing that catches your eye in the morning is the storage on top of your closet. When you have a lot of rubble in your home, hidden somewhere high up, it will have an overall overwhelming effect on you. In addition, you may be suffer for headaches.

Get rid of unnecessary clothes

Do you have clothes that you haven’t worn for a long time, but keep “probably just in case”? happening(source not specified) "?

One woman said at my seminar that when her husband received the settlement, they decided to go crazy and buy her two really nice suits “in case” they never had more(source not specified) there will not be enough money to purchase something like that.

Two years have passed since then, and she has never worn one of these costumes. She believes that the money was thrown away.

Some people keep things they haven't worn for 20 years. They say that if you keep them long enough, they will come back into fashion. My advice to you: if you have never worn an item for last year, not to mention, if you haven't worn it for two or three years in a row, part with it, sell it, trade it, burn it, or just throw it away.

Feng Shui and clothing Feng Shui masters say that clothing should always be neat and attractive so that the Lady...

A rubble is a chaotic accumulation building materials and structures, debris of technological equipment, sanitary devices, furniture, household utensils, stones.

The sudden collapse of buildings and structures can be caused by errors made during the design, deviations from the project during construction work, or violations of the rules for installing structures.

There is poor quality of construction work and the use of substandard building materials. A noticeable influence is exerted by underground karst cavities formed underground under the influence of water flows. Uncoordinated housing redevelopments can lead to catastrophic consequences for the building.

In some cases, the cause of the collapse may be the lack of reliable ventilation in the room where gas is used. Collapses are facilitated by explosions due to gas leaks, improper operation of household gas appliances, careless handling of fire, and storage of flammable liquids and explosives indoors.

In addition, the collapse of a structure is possible due to a man-made emergency, as well as during natural disasters, and, first of all, during an earthquake. Destruction can be a consequence not only of the force of the elements, but also poor quality buildings or their technical wear and tear.

It is also impossible to exclude a terrorist attack and local military actions using various types weapons.

The degree of damage to buildings depends on the strength of the destructive factor, the duration of its impact, the seismic resistance of structures, the quality of construction, and the degree of wear (aging) of buildings.

According to the degree of destruction of buildings, rubble is divided into five types.

1. Light damage: thin cracks appear on the walls of buildings, plaster crumbles, no chips big pieces, the glass in the windows is damaged.

2. Weak destruction: small cracks in the walls, quite large pieces of plaster break off, cracks appear in the chimneys, some of them are destroyed, the roof is partially damaged, and the glass in the windows is completely broken.

3. Moderate destruction: large cracks in the walls of buildings, collapse of chimneys, partial fall of the roof.

4. Severe destruction: collapse internal partitions and walls, breaks in walls, collapse of parts of buildings, destruction of connections between parts of buildings, collapse of the roof.

5. Complete destruction.

The rubble can be continuous or isolated (local).

The rubble is conventionally divided into reinforced concrete and brick.

Reinforced concrete rubble consists of fragments of reinforced concrete, concrete, metal and wooden structures, debris brickwork, elements of technological equipment. They are characterized by the presence of a large number of large elements, often interconnected, voids and unstable elements.

Brick rubble consists of brick blocks, broken bricks, plaster, fragments of reinforced concrete, metal, and wooden structures. They are characterized by high density, the absence of large, as a rule, elements and voids.

The formation of blockages is accompanied by damage to electrical, thermal, gas, plumbing and other systems. This creates a threat of fires, explosions, flooding, damage electric shock. The rubble of industrial buildings in which hazardous substances are produced or stored is especially dangerous.

The destruction of buildings and the formation of rubble is usually accompanied by death, blocking, and injury to people. Of all those injured in the rubble, approximately 40% receive minor injuries, 20% receive moderate injuries, and the same percentage receive severe and extremely severe injuries and mutilations.

Almost all the rubble ends up with people, some of them die immediately, some are injured. In the first day after an emergency, in the absence of first aid, approximately 40% of the victims die in the rubble. After 3-4 days after the formation of the blockage, the living people in it begin to die from thirst, cold, and injuries. After 7-10 days, there are practically no living people left in the rubble.

More on the topic Reasons for the formation of rubble:

1. N 4. Techniques and rules of forensically similar investigative actions
2. Law and morality are very close concepts Interview with the Chairman of the Association of Lawyers of Russia Veniamin Fedorovich Yakovlev

Inspecting unstable structures in rubble is an extremely dangerous operation for rescuers. Therefore, inspection of voids cannot be undertaken until the sufficient quantity qualified employees and necessary equipment.
Rescuers should have basic knowledge of the types of debris. The following types of rubble are distinguished (most typical for panel buildings):
- flat blockage,
- one-sided blockage with support,
- one-sided blockage without support,
- V-shaped blockage,
- A-shaped block.
A flat rock (Fig. 1) is the result of a fall load-bearing wall. The walls and roof in this case literally “fold”. Large objects that are located inside the building break the walls, and voids can be created around them. Rescuers should try to find existing entrances to buildings - entrances, flights of stairs to begin searching for victims.

Fig.1. Flat rock

One-sided rubble (Fig. 2) occurs when a load-bearing wall supporting a roof or floors collapses on one side. One-sided supported collapses are the result of a falling wall or roof that, in the process of falling, rests on existing objects in the building, such as the opposite wall.

Rice. 2. One-sided blockage

One-sided blockages without support (Fig. 3) are a very unstable type of blockage. A fallen wall hangs in the air without support. Additional weight on it, movement, and shifting of nearby debris can lead to further collapse.

Rice. 3. One-sided blockages without support

Therefore, voids can only be examined after the rubble has been stabilized using appropriate equipment, which is not usually at the disposal of rescuers. Rescuers in this case must focus on collecting information about the exact location of the victims and protecting them, but in such a way as not to provoke a further collapse.
A V-shaped collapse (Fig. 4) is usually the result of the fall of an internal load-bearing wall, column, roof, etc. In this case, when a wall or roof falls, it breaks in the middle, resting at this point on the floors of the lower floor. Voids can appear on both sides of the fault.

Rice. 4. V-shaped block

With an A-shaped collapse (Fig. 5), the floors between floors collapse, but when they fall, they rest on the internal load-bearing walls.

Rice. 5. A-shaped block

One of the most likely dangers for rescuers when working in rubble is the possibility of further collapse of structures above the resulting voids. Therefore, these structures must be stabilized. Various equipment can be used for stabilization. For example, wooden towns, screw jacks, air springs, hydraulic tools, telescopic stands.
Wooden towns (Fig. 6) are the most practical way to stabilize the rubble. It should be borne in mind that they should not move the components of the obstruction, and should be used only for support and pores.

Rubble is formed as a result of the collapse of buildings and structures caused by earthquakes, explosions, storms, hurricanes, tornadoes, mudflows, landslides and other natural and man-made phenomena. The nature of the blockage depends on the source (reason) of its formation, on the type and duration of action damaging factor, on the type and number of storeys of buildings, on the features of development and other factors. The degree of destruction of buildings is divided into four categories (Table 1.1).

Table 1.1. Characteristics of the degree of destruction of buildings.

The rubble is a chaotic accumulation of large and small fragments of building structures, technological equipment, utility devices, furniture, etc.

Large gaps may remain in the thickness of the rubble, through which smells and sounds from the person located there can freely pass. This makes it easier to find people trapped in the rubble.

The most characteristic of rubble is a pile of collapsed building structures, their individual fragments, including concrete fragments, reinforced concrete structures and brickwork up to 0.8 m 3 and construction waste.

The volume of rubble during the destruction of residential buildings is 35-50%, industrial buildings- 15-20% of the construction volume. The volume of voids in the rubble is 40-60%. Highest height debris of residential buildings - 1/5-1/7, and industrial buildings - 1/4-1/10 of their height. The average slope angle of the rubble is 30°.

Table 1.2. Structure of the rubble.

The destruction of buildings during an emergency is accompanied by blocking of people and their defeat.

Number irrecoverable losses at the time of destruction of buildings and structures, the average value can be equal to 10-20% of total number injured.

Damage in disasters is usually accompanied by mechanical injuries:

40% of those affected have a mild degree of damage;

20% of those affected - average degree;

20% of those affected are severe;

20% of those affected are extremely severe.

During the liquidation of the consequences of the earthquake in Spitak (Armenia) in 1988, due to the peculiarities of the process of destruction of buildings and structures, relatively large number those killed at the time of the earthquake and within two days from the moment of the earthquake (from total number dead during this time) was found in the upper layers of the rubble, and in absolute terms for the upper layers of the rubble, the number of dead exceeded the number of living people who were in this layer of the rubble.

Starting 3-4 days after the earthquake, people who were alive under the rubble begin to die from hypothermia, thirst and other reasons. As a result, after 7-10 days the chances of finding a living person in the rubble are almost zero.

As the rubble is cleared, the number of people being pulled out alive increases.

As a rule, about half of victims (40-50%) are unable to report their existence due to their injuries. In the first days after the injury, in the absence of medical care, the mortality rate among victims can reach 40%.