RU2588511C2 - Method for soil and device for its implementation - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention can be used for securing of soil. Method involves formation of wells, introduction to the well extended charge, supply of hardening composition, and after filling the well compound elongated charge is exploded, and after explosion well again filled with compound. Input into the well of elongated charge and well filling compound is reciprocal over-rolling in well casing. Supply of hardening composition is performed in the cavity formed by the well wall and cover. In the cavity formed by bent sections of the shell, fluid is fed agent and shell is periodically rolled from the well. Elongated charges are placed between the well wall and cover.

EFFECT: increasing carrying capacity of a pile.

2 cl, 1 dwg

Description

The invention relates to the construction, in particular the construction of bridges, structures in the aquatic environment, as well as the construction of buildings and structures on water-saturated soils. Currently, there is a widely known method of fixing the soil by pumping in them different compositions that actively react with the soil (see, for example, V.E. Sokolovich "Chemical fixing of soils", M. - Stroyizdat. - 1980. - P. 3).

The main disadvantage of fixing soils with chemical compositions is that the chemical activity of different soils is not the same. This necessitated the creation of a large number of different fixing compositions (see, for example, the USSR AS NN 1467137, 1622515, 166274, Pat. RF N 2035544 and others, MKI Ε02D 3/12). In addition, this method cannot be used to fix soils, the degree of moisture of which exceeds 0.6 units, poorly permeable soils, quicksand, etc.

This drawback is deprived of the method of fixing the soil and consisting in pumping cement or soil-cement mortar into the soil through drilled wells or injectors (see, for example, L. B. Goncharova, “Fundamentals of Artificial Soil Improvement”, M. University of Moscow Publishing House, 1973, p. 331 )

However, when applying this method, cement consumption is high. So in the geological conditions of the city of Rostov-on-Don and the Rostov region, a number of regions of the North Caucasus and Western Siberia for fixing subsidence and weak base soils under the foundation, for example, a 9-story 72-apartment building of 87-072 / 1.2 p series is consumed up to 600 tons of Portland cement grade 400-500.

At the same time, geological sections of the soils of these regions to the depth of consolidation, as shown by long-term studies, are several geological elements (several layers of soil) having different compositions, physico-mechanical properties and chemical activity, for example, silty sands, subsidence loesslike soils, quicksand, silts, etc. The alternation and number of such geological elements can be very different even within the same settlement.

Also, this method cannot be used to erect the foundations of structures in the aquatic environment.

Existing technologies for the chemical fixation of subsidence soils with a moisture content above 18% do not allow providing strength design parameters for soil consolidation.

This is due to leaching from the absorbing complex and leaching from the soil mass, which is fixed, calcium salts and other water-soluble salts involved in the exchange reactions of consolidation.

A chemical technology has been developed for the fixation of subsidence-saturated water-saturated soils and floats (over 20% moisture), which allows for the continuous fixation of soils using injected components by 90-95%.

The proposed technology includes the construction of wells, the formation of injection zones in them and the supply of chemical solutions to the fixed array through a system of injectors. First, an aqueous solution of calcium oxide hydrate is injected into injected soil through injectors by successive injections from top to bottom to the entire depth of consolidation, and then by sequential injections, but from below upward injected a solution of sodium silicate with modifying additives (the composition of modifying additives is KNOW-HOW). Injectors for injecting the second solution are located between the injectors for injecting the first solution and the second solution.

The technology is protected by Ukrainian patent No. 75409, with priority dated December 29, 2003.

This technology does not allow to build the foundations of structures in the aquatic environment, for example, to build piles of bridges in the sea.

A known method that can be used to fix waterlogged clay and below their weak subsidence soils during reconstruction and construction of buildings and structures, as well as to increase the stability of natural landslide slopes, artificial slopes of dams, pits and sides of quarries. A method of fixing waterlogged clay and subsidence soils involves performing in waterlogged soils a vertical or inclined cavity and forming in it by filling this cavity with an incoherent composition.

From the technical level there is a known method for fixing weak soils, including creating a cylindrical cavity in the surface, strengthening the walls with a cylindrical conductor pipe and injecting a hardening solution by feeding it under pressure into the soil through an injector. In soils of high power, a cylindrical cavity is created and its walls are strengthened by a conductor pipe by its simultaneous immersion under vibration with an auxiliary pipe placed in it coaxially, the outer diameter of which is determined by a certain dependence. The auxiliary pipe is removed from the conductor pipe when the depth of the upper boundary of the weak soils to be fixed is reached. Under the influence of vibration, the injector is immersed through the conductor pipe to the full power of the fixed thickness of soft soils, it is sealed in the conductor and a hardening solution is pumped through it at intervals, each time raising the injector to the height of the next injected interval. All injection operations at one fixing point are performed during the relaxation of the soil, compacted with vibration immersion of the conductor and injector. The technical result consists in increasing labor productivity, reducing the duration of the process, reducing costs, saving energy and manufacturability of the method (Pat. No. 2256028 for an invention, publ. 101.07.2005. Bull. 19).

The disadvantage of this method is that the diameter of the seal when driving the conductors does not exceed three external radii of the cross section of the conductor pipe and lasts only up to 3 days, i.e. this is an auxiliary measure that provides the possibility of fixing the underlying soils, and the upper soils in the process of relaxation or soaking soften and take on natural strength.

This method is also unacceptable for the construction of structures in the aquatic environment.

There is also known a method of fixing the soil, including determining the number, order of occurrence, thickness and properties of geological elements in the geological section of the fixed array of soil with subsequent fixing of the soil with individual entries from bottom to top along the height of the fixed soil. What is new is that in geological elements with the greatest subsidence properties, bored piles are erected using casing by completely replacing the soil with concrete mixture, and in the remaining geological elements erected cement-cement piles by jet technology, with each subsequent drilling run after the pile erected by the previous entry will gain strength sufficient to hold the soil fixed during the next entry, and the bored and soil-cement piles are erected coaxially. The technical result of the invention is to increase the degree of consolidation and bearing capacity of the soil while reducing construction time and reducing concrete consumption (Patent No. 2209267).

The disadvantage of this method is its low technology, because for each engineering-geological element, it is necessary to use its own fixing technology, therefore, at each point, re-install other technological equipment, and since the construction of each pile is performed according to the scheme from the bottom up, after the first pile element is installed, the entire cavity located above this element, in flooded soils floats with soil and concrete residues, then the implementation of the next element up will be practically impossible.

This method is also unacceptable for the construction of piles in the sea on the floating.

The closest in the set of essential features and selected as a prototype is the "Method of strengthening the basis of symmetrically loaded foundations" (Patent RU No. 20269926. Published 01.20.1995).

Improving the effectiveness of compaction of foundations when reconstructing or strengthening emergency buildings, as well as expanding the scope of application in sandy and flooded clay soils, is achieved by drilling with the help of a pneumatic punch for deviated wells, followed by compaction with an inert material, such as crushed stone. In this case, inert material is poured into the well in portions equal to 1 / 3-1 / 2 of the length of the punch, followed by compaction.

The disadvantage of this method is the limited depth when performing the cavity with pneumatic punches, the discreteness of the piles in individual runs, the low strength of its material. These disadvantages lead to an increase in the volume of consolidation to provide the necessary bearing capacity of the base.

The fixing depth in the known method is limited by the length of the pneumatic punch, and the strength of the base material - by the density of natural soil.

The method is unsuitable without preliminary costs in the presence of underlying weak and subsiding rocks below the bottom of the piles being built.

This method is also unsuitable for use in the aquatic environment.

A known method of compaction of subsidence soils (see "Recommendations for compaction of subsidence soils of high power by the hydraulic blasting method." - M .: Stroyizdat, 1984, pp. 3-12, Fig. 2, 6) (1) by means of excavation, drilling of drainage and blast holes, while drainage wells are filled with drainage material, which drains water during the soaking of the wells and ensures the stability of the walls of the wells, i.e. protects them from swimming off, and pipes for supplying the mixture by soaking and seismic action are installed in blast holes. The essence of the invention: the formation of a pit, drilling of drainage and blast holes with fixing their walls, soaking of the soil, placement of explosive charges in the wells and the explosion of charges with soil sediment under its own weight.

The walls of the wells are fixed by firing them at a temperature of 400-1000С in the form of an annular layer to a depth equal to 2/3 of the subsiding thickness. Then, the subsidence stratum is soaked through a pit and drainage wells, or only through drainage wells, after water saturation of the subsidence stratum soil through transport pipes and through blasting holes, the explosive charge is transported and exploded, while the structural bonds of the water-saturated soil are destroyed and the soil is intensely compacted.

This method is also unsuitable for fixing large tracts of soil.

In the book of L. B. Goncharova “Fundamentals of artificial improvement of soils, M., ISU, p. 124, however, the goal and end result are completely different, firstly, in the proposed method of compaction of soils, a well-known technological technique is used to bake soil only in the walls of the well with a thickness of 10- 15 cm around it to obtain a “cylinder” of burnt soil, replacing the functions of the pipe, in order to protect against slipping and maintain its stability so that after soaking it would be possible to immerse explosive charges in its cavity wa to the required depth of subsidence and thereby exclusion from the technology of sealing scarce pipes. Secondly, soil firing in the walls of the wells is used to increase the filtration capacity of the wells, i.e. its flow rate in order to accelerate the process of soaking the soils of subsiding thickness, while excluding drainage material (crushed stone and sand) from the compaction technology. At the same time, soil firing in the walls of the wells is carried out only at 2/3 of the depth of the subsidence thickness.

The final result of the subsidence thickness of the application of soil roasting in the proposed method is to increase the efficiency of compaction of subsidence soils by reducing the volume of drilling operations, speeding up the process of soaking the subsidence thickness, saving pipes and drainage material, while the end result of roasting the soils in the known method to eliminate soil subsidence due to their thermal fortifications in subsidence. In this case, the purpose of soil firing is to obtain fixed massifs (soil columns) with a diameter of 2-3 m each. Moreover, soil roasting becomes effective only if it is implemented to the full depth of the subsidence thickness.

If in the proposed method ultimately the elimination of subsidence occurs due to the destruction of natural bonds between soil particles and, consequently, the soil structure and its compaction, then in the known method, the elimination of subsidence occurs on the contrary due to the strengthening of natural bonds. A distinctive feature of the proposed method in comparison with the prototype is that blast holes are simultaneously drainage, and the protection of their walls from slipping is carried out by firing the soil around them, while the soil is fired at a depth of 2/3 of the thickness of the subsiding thickness.

According to the prototype, the walls of blast holes are protected from swimming by chemical methods, for example, by silicatization. At the same time, liquid glass or other reagents are injected into the pores of the soil, where a gel of silicic acid or other acids is formed as a result of chemical reactions, as a result of which the soil is strengthened in the walls of the wells, but they become waterproof, which forces drainage wells to be drilled along with blast holes, while protecting their walls from swimming off and ensuring water filtration by filling with crushed stone or coarse-grained sand, the depth of fixing of blast holes does not exceed the depth of the beginning total subsidence pressure, i.e., not more than 6-7 m, which is not enough with a large thickness of subsidence, for example, 30-40 m, because the effect of the blast wave at such a depth is very weak. The method is very laborious.

A known method of compaction of the soil, including drilling a well, laying explosives in the well, and compaction of the well with an explosion. Patent 2346111 C2, E02D 3/10, 2006.01.

The disadvantage of this method is that it is not suitable for the manufacture of bored piles and fastening large tracts of soil, as well as insufficient bearing capacity of the piles, which leads to the manufacture of additional piles.

Also, the method and device do not allow them to be used for the formation of piles in the aquatic environment and on floats.

The objective of the invention is to increase the bearing capacity of the manufactured piles on the action of vertical and horizontal loads, as well as reducing the cost of manufacturing a bored pile and increasing the volume of fixed soil.

The problem is solved by the combined use of a group of inventions.

The expected technical result from the use of the invention is to use a method including forming a well, introducing an elongated charge into the well, supplying a hardening composition to the well, and after filling the well with a hardening composition, the elongated charge is blown up, after the explosion, the well is filled again with a hardening composition. In this case, an elongated charge is introduced into the well and the well is filled with a hardening composition by reciprocating rolling of the shell in the well, and the hardening composition is supplied into the cavity formed by the wall of the well and the shell, while a fluid agent and the shell are fed into the cavity formed by the bent sections of the shell. periodically rolled out of the well, with elongated charges placed between the wall of the well and the shell.

The method is carried out by a device including a traction body, a fluid supply system and a hardening composition supply system, a chamber along the perimeter of which is fixed to the shell end, and the second shell end is bent and connected by a cable to the traction body, while an elongated charge is placed in the bent portion of the shell and one end thereof is connected with a fuse, and its second end is fixed at the wellhead.

The drawing shows a device for implementing the method.

The device is made of a chamber 1, which is in communication with a fluid agent supply system 2, with a hardening composition feed system 3. The system 2 is in communication with the cavity 4. The supply system 3 of the hardening composition is in communication with the cavity 5, which is formed by the shell 6 and the wall 7 of the well. The end 8 of the shell is fixed around the perimeter of the chamber 1. The second end 9 is connected by a cable 10 to the traction body 11. An elongated charge 12 is placed inside the bent portion of the shell 6, which is electrically connected through the igniter and cable 13 to the electric current source 14.

The shell 6 in the chamber 1 is laid with hoses 15. An elongated charge 12 goes around the shell 6 and the anchor 16 is fixed to pound 17.

The device operates as follows.

Wells are drilled or punctured in any known manner. The direction of the well can be: vertical, horizontal or inclined.

At the wellhead, in any known manner, a chamber 1 is attached. Air is supplied to the chamber 1 by a fluid agent supply system 2. The shell 6 rolls along the well and lays an elongated charge 12 on the wall 7 of the well. After the entire shell 6 rolls out, the elongated charge 7 will be completely laid on the wall of the well 7.

The hardening composition feed system 3 injects a hardening composition into the well that compresses the air in the shell 6 and enters the well through the gap formed by the wall 7 of the well and the shell 6.

Traction body 11, the shell 6 is pulled out of the well 7. The air in the shell 6 is compressed. After reaching the specified air pressure in the shell 6, the cable 10 is weakened. The air in the shell 6 expands. The shell 6 and the hardening composition are accelerated and hit the ground 17 of the well 7. In this case, the hardening composition is rammed into the ground 17 of the well 7. The shell 6 compacts the hardening composition in the cavity 5. Then again, the sheath 6 is again pulled out of the well 7 by the traction body 11. Part of the cable 10 wound on the traction body 11. When the cable 10 is relaxed, only part of the cable 10 is released from the traction body 11. The shell 6 is moved back and forth at a different level of the well 7.

System 3 injected into the well a new portion of the hardening composition.

Thus gradually compacting the soil along the entire height of the well 7.

After compaction of 8/10 depths, an elongated charge 12 is blown up. After that, the shell 6 is completely removed from the well and system 3 is filled with a hardening composition. After that, the camera is dismantled from the wellhead.

Example.

Waterlogged clay soil has the following characteristics:

- the power of the fixed soil 17-19 m;

- water content 78%;

- length of cement pile 40 m.

The composition of the hardening composition:

- sand 63%;

- cement 18%;

- basalt fiber 5%;

- polymer Veselovsky "Silor-Ultra" 14%;

- pile diameter 300 mm.

The method was carried out by the device depicted in the drawing.

A puncture method made a hole with a diameter of 300 mm and a length of 25 m, then an elongated charge of ammonite with a total weight of 40 kg was introduced into the hole. After that, a hardening composition was pumped into the hole, which was kept in the cavity for 25 hours. The strength of the piles was 7.4 MPa. The use of the invention increases the bearing capacity of piles.

Claims (2)

1. A method of fixing the soil, including: forming a well, introducing an elongated charge into the well, supplying a hardening composition to the well, and after filling the well with a hardening composition, the elongated charge is blown up, and after the blast, the well is filled again with a hardening composition, while the elongated charge is introduced into the well and filling the well with a hardening composition is carried out by reciprocating rolling of the shell in the well, wherein the hardening composition is supplied into the cavity formed by the wall of the well and the shell, m into the cavity formed by the bent sections of the shell, a fluid agent is supplied and the shell is periodically rolled out of the well, with elongated charges being placed between the wall of the well and the shell. 2. A device for fixing the soil, including a traction body, a fluid supply system and a hardening composition of the chamber, the perimeter of which is attached to the end of the shell, and the second end of the shell is bent and connected by a cable to the traction body, while an elongated charge is placed in the bent portion of the shell and its one end is connected to the fuse, and the second end is fixed to the wellhead, and the hardening composition feed system is in communication with the cavity formed by the shell 5 and the borehole wall 7.

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