The film was created by order of the Ministry of Higher and Secondary Specialized Education of the RSFSR as a teaching aid for studying unstable soils and methods of strengthening them before the construction of various facilities.
A city street.
Cracks in the facades of houses.
This is the result of uneven subsidence of the soil under the buildings.
Structures on rocky soils.
A hydroelectric dam.
A birch grove.
Almost the entire surface of the USSR is covered with soft soils - clayey and sandy.
A dune.
Sand is crumbling.
Unstable clayey soils, the so-called loess soils, occupy up to 20% of the territory of the USSR. They are characterized by a macroporous structure.
A ravine, the steep sides of which consist of loess soil.
Macropores are pores visible to the naked eye in the form of vertical channels penetrating the thickness of the loess.
The porosity of loess soil often reaches 45-55%.
Loess particles are linked together by salt deposits.
These bonds are strong only when dry.
Under the influence of water, the structural bonds between the loess particles are destroyed.
A cartoon showing and explaining such destruction.
Workers on a drilling rig thoroughly examine geological and hydrogeological soil conditions.
Depending on them, one or another method of improving the construction properties of the soil is used.
Mechanical impact or pressing action destroys the natural structure of the soil.
An impact tool is in operation, the soil is rolled by rollers.
A cartoon showing changes in the soil after this method of processing.
Sandy and clayey soils are compacted by multiple passes of rollers or earthmoving machines over the same area.
Rollers with smooth rollers compact the soil after 6-8 passes, in layers up to 15 cm.
Cam rollers can compact soil up to 50 cm in 5-6 passes.
Rollers on pneumatic wheels.
The large contact area of the tires with the soil allows it to be compacted in 4-6 passes to a depth of 40 cm.
When rollers are operating, the first pass is made at low speed to form a flat and dense surface.
Clayey soils are mainly compacted by rolling.
Vibratory rollers are the most effective for compacting loose sandy soils.
A cartoon showing such a roller in action.
The combined effects of vibration and rolling allow compacting a soil layer up to 60 cm in 2-4 passes of a vibratory roller.
Subsidence of the upper layer of loess soil can be eliminated by installing a dense soil cushion.
To do this, dig a pit 1.5-2 meters deeper than the foundation.
Then, using imported or previously excavated soil, begin backfilling the first layer.
Moistening the soil with special equipment.
Compaction of the first layer with cam rollers.
After compacting the first layer to the required density, backfilling, moistening and compaction of subsequent layers is carried out until they reach 1.5-2 meters.
The soil cushion does not have subsidence and the pressure from the foundation is distributed over a large area.
Compaction does not require a wide front of work and backfilling the soil in thin layers, as with rolling.
Large machine operator, carrying out the dumping of cargo from a height of 2.0 to 4.0 meters.
The rammer weighing 2-4 tons destroys the natural structure of the soil with the energy of its fall and compacts it.
Heavy rammers compact the soil in a limited area.
Compaction is carried out until the settlement with each fall of the rammer is equal to 1-2 cm.
Cartoon explaining the effect of this method on the soil.
Soil compaction with special rammers.
Compaction is carried out by five diesel rammers, which are installed on a tractor.
The rammers work on the principle of diesel hammers.
A diesel rammer compacts a soil layer up to 80 cm thick in 3-4 passes.
The main disadvantage of all impact mechanisms is dependence on the weather.
Construction, Priming, Soil compaction, Tamping
Cable-percussion drilling rigs are in operation.
Such rigs are used for deep compaction of subsidence soils.
For this purpose, the drill bit is replaced with a special tip, and a guide conductor is installed at the wellhead.
A cartoon explaining the process of deep compaction.
Then the well is filled with soil.
The soil is supplied by a dispenser in portions weighing about 300 kg.
A cartoon explaining the process of layer-by-layer ramming.
Soil piles penetrate the entire subsidence layer and improve its bearing capacity.
A cable-percussion drilling rig drills a hole in light loess soils with a diameter of up to 50 cm to a depth of 8 meters in 30-50 minutes.
The quality of compaction is checked by sampling in an area limited by three dug soil piles.
During the manufacturing of soil piles, a loosened, so-called buffer layer remains on the surface, which is removed before the main work begins.
The tractor clears the working surface.
A reinforced concrete grillage is placed on the heads of the soil piles.
During chemical consolidation, solutions of salts, resins or polymers are injected into the soil.
A cartoon about the effect of chemicals on soil.
Some loess soils contain a lot of calcium salts and are strengthened with one solution of sodium silicate or liquid glass.
Sandy and dusty soils require the introduction of two solutions - liquid glass and its hardener calcium chloride.
Breaking out the site for the building.
The locations of the injectors through which the solution is injected are marked.
Site with injectors.
Before starting work, the injectors are washed.
Liquid glass solution is delivered in heated tanks.
The concentration of the solution is checked with a hydrometer.
Then the solution is pumped into a tank, which is under pressure and ensures an uninterrupted supply of liquid glass to the injectors.
The compressor maintains the required pressure in the entire system.
Manual driving of injectors.
A loader equipped with a special device can immerse the injector and extract it from the soil.
The pressure during injection of the solution is set depending on the filtration capacity of the soil within 1-3 atmospheres.
Control devices allow maintaining the correct mode of the silicification process.
Cartoon explaining the silicification process.
A pit is opened to control the quality of the processed soil.
A soil sample from the pit is examined in the laboratory.
In clay soils with a low filtration coefficient, the efficiency of silicification can be increased by electroosmosis.
During electrosilication, a source of direct electric current, injectors and steel rods form a single circuit.
Construction, Priming, Deep compaction, Soil piles, Silicification
Cartoon explaining soil stabilization with synthetic resin.
Buildings constructed on soils reinforced in this way in the city of Rostov-on-Don, Nikopol, Odessa, Zaporozhye.
Soviet scientists use the method of soil stabilization with synthetic resin in the construction of a dam in Aswan, Egypt.
The thermochemical method is based on the property of clay soils to turn into a rock-like material under the influence of high temperatures and combustion products or special additives.
Cartoon explaining this method.
When using the thermochemical method, first of all, wells are drilled.
Then the wellhead and the pipe space are carefully sealed, a conductor is installed, and asbestos gaskets are laid.
A slab is placed on a layer of clay mortar.
The slab serves to seal the well, provide counterpressure, and secure ground equipment.
If liquid fuel is available, an installation is used that includes a compressed air generator, liquid fuel tanks, and fuel combustion equipment.
After the equipment has been installed and tested, ignition begins.
The gas burner heats the walls of the combustion chamber to the autoignition temperature of the combustible mixture.
A cartoon explaining the processes that occur when using this method.
During soil processing, it is necessary to regularly check the pressure and temperature.
A cartoon explaining the processes that can occur when the melting temperature of the soil is exceeded.
The worker monitors the temperature and pressure values in the well.
In conditions where there is combustible gas, an installation is used that includes a compressed air generator, a gas distribution point, and equipment for the primary ignition of the fuel.
Air distribution manifolds allow you to process several wells at once.
Thermocouples are used to monitor the soil temperature outside the well.
The combustion mode is monitored through a control peephole.
Before constructing the above-ground part of the building, the bearing capacity of the soil columns is checked with a static load.
The test rig is placed exactly in the center of the column.
Testing.
The results are recorded in the log.
A welder works on metal structures of a construction site.
City streets.
Installation of reinforced concrete floors.
Reinforced concrete frame of a building.
Industrial building.
Construction, Priming, Deep compaction, Thermo-chemical sealing