RU2605213C1 - Method of erection ramming design in soil - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to construction, namely to technology of construction of structures, for example piles in soils. Method includes formation of well, supply of hardening material, installation of switching discharger with electrodes in it, connected to source of pulsed electric discharges, excitation of high-voltage electric discharges with help of emitter. Wherein each high-voltage discharge is performed with simultaneous supply of non-detonating exothermic mixture in interelectrode space of emitter and its burning at high-voltage electrochemical explosion. Wherein non-detonating exothermic mixture in interelectrode space is dibenzoylperoxide, or a mixture of dibenzoylperoxide with ditertbutylperoxide, or mixture of dibenzoylperoxide with tertbutylperbenzoate in ratios in mixtures of (1:1)-(3:1).

EFFECT: technical result is increased efficiency and reliability of method of replacement of gas composition on mix of various peroxide compounds, which are individual compounds and possess ability of forming strong shock wave during decomposition to create broadening.

1 cl, 2 dwg, 1 tbl

Description

The invention relates to construction, and in particular to the technology of erection of structures, for example, piles in soils where the stability of the walls of boreholes is not ensured, can be used for pile foundations of new buildings and structures under construction, reconstructed old buildings, as well as structures for various purposes.

Bored piles are widely used to strengthen the overloaded bases of buildings and structures; construction of new facilities close to existing facilities; strengthening the foundations of existing buildings in connection with the reconstruction or increase of operational loads; adjusting the roll of the building or individual foundations; landslide protection of buildings; reconstruction and construction in cramped conditions inside existing facilities; reinforcement of railway embankments with an unstable ballast train; construction of new facilities in difficult ground conditions.

A known method of manufacturing a bored pile with a broadened heel, including drilling a well under a pile, lowering an explosive charge to the bottom of a well, filling a well with concrete, blasting a detonating explosive charge and forming camouflage broadening of the lower end of the pile in the ground (I. Ganichev, “Device for artificial foundations and foundations. "M., Stroyizdat, 1981, p. 65).

The disadvantage of this method is the inadmissibility of its use in reconstruction, inside existing facilities due to an uncontrolled explosion from detonation, seismic effects on surrounding objects, etc.

There is a method of erecting a pile by stuffing, including performing a well drilling, feeding into it a hardening material, compacting it using electric discharges with moving the excitation zone from bottom to top, characterized in that the drilling is carried out by a screw projectile, at the end of which an electric spark gap is placed with the possibility of extension hardening material is fed into the well according to the flanges of the screw projectile; when the shell reaches the bottom of the well, it is raised without rotation in the well to a height of 0.8-1.5 diameters hole of the well, and after filling the formed volume with continuously supplied hardening material, the spark gap is extended and electric discharge is carried out, then the operations of raising the projectile and electric discharges to fill the well to the full depth are repeated, which contributes to the broadening of the well and increase the adhesion of the well to the soil RU 2318960, IPC E02D 5 / 34, publ. 03/10/2008.

The disadvantage of this composition is the insufficient width of the printed pile.

The closest in technical essence to the claimed solution is a method of erecting a printed structure in the soil, which includes forming a well, supplying a hardening material to the well, installing an inventory electric emitter connected to a source of pulsed electric discharges in it, exciting high-voltage electric discharges using an emitter with subsequent extraction of it from the well, characterized in that at least one high-voltage discharge is produced simultaneously by feeding a non-detonating water-filled exothermic mixture into the interelectrode space of the emitter and burning it during a high-voltage electrochemical explosion with the release of gases, steam and plasma and creating a pressure of up to 100 MPa and a shock wave that further expand the well, with soil compaction of its walls and filling the well with hardening material RU 2221918 , IPC E02D 5/34, E02D 5/38, publ. 01/20/2004.

The disadvantage of this method is its low efficiency for creating high pressure when broadening the well, as well as unreliability due to the lack of stability of the applied exothermic water-filled mixture.

The objective of the invention is to provide a more efficient and reliable method of erecting a printed pile with a wider heel, which allows to obtain high-quality piles, to provide high bearing capacity and strength of the material of the structure.

The technical result of the invention is to increase the efficiency and reliability of the method, replacing a non-detonating composition with a mixture of various peroxide compounds, which are individual compounds and having the ability to decompose to obtain a stronger shock wave to create broadening.

The technical result is achieved due to the fact that in the method of erecting a printed structure in the soil, including forming a well, supplying a hardening material to the well, installing therein a switching arrester electrodes connected to a source of pulsed electric discharges, exciting high-voltage electric discharges using an emitter, wherein each high-voltage discharge is produced with the simultaneous supply of a non-detonating exothermic mixture into the interelectrode space of the spark gap and its combustion during a high-voltage electrochemical explosion in accordance with the claimed invention, as a non-detonating exothermic mixture, a mixture of dibenzoyl peroxide with ditretbutyl peroxide or a mixture of dibenzoyl peroxide with tert-butyl perbenzoate in the ratios in the mixtures (1: 1) - (3: 1) is fed into the interelectrode space. As hardening material can be used, for example, concrete mix.

The novelty of the method is to improve the effectiveness of the broadening ability of a non-detonating mixture when using a non-aqueous mixture of dibenzoyl peroxide with ditretbutyl peroxide or with tert-butyl perbenzoate at a different ratio as mentioned above.

From information sources it is not known to use dibenzoyl peroxide with ditretbutyl peroxide or a mixture of dibenzoyl peroxide with tert-butyl perbenzoate as a non-detonating exothermic mixture in ratios in mixtures (1: 1) to (3: 1) in combination with a high-voltage discharge in a hardening material. Therefore, we can conclude that the invention meets the criterion of inventive step.

In fig. 1a shows the drilling of a well 1 with a screw projectile 2 with a spark gap and a capsule with a non-detonating mixture 3 at its lower end, its subsequent burning at a height (0.8-1.5) d of the diameter of the well by applying a high-voltage voltage pulse through an electric spark gap to form camouflage cavity and subsequent filling with hardening material of this cavity. The process is presented in fig. 1b, in fig. 2c shows the next projectile rise to a height of (0.8-1.5) d from the surface of the hardening material 4; in fig. 2 g shows the resulting stuffed pile with a broadened heel 5.

The method is as follows. Excavate a cylindrical well 1 with a screw drill 2. At the same time as drilling, excavation takes place. After the drill has passed to the required depth, it is lifted to a height (0.8-1.5) of the diameter of the obtained well 1. A height equal to (0.8-1.5) of the diameter of the obtained well is determined empirically based on the condition of soil disintegration in the resulting well when lifting the projectile and is known in the art of such structures. Its lower limit is taken for soils that are weak with respect to crumbling, for example, dusty sand, nutrients, and the like. The highest limit is defined for cohesive soils. Simultaneously with the lifting of the drill, the hardening material 4 begins to flow, which can be fed by gravity due to gravitational forces, pressure applied to the hardening material, and after the shell reaches the desired height, the drill can be rotated in the direction opposite to the drilling direction to accelerate the filling of raising the volume under the projectile 2 and creating some pressure to better fill the above volume. The proposed non-detonating mixture is supplied in a cartridge (capsule) of a polymer material, which is additionally attached to an electric spark gap. The cartridge (capsule) contains a non-detonating mixture consisting of a mixture of non-aqueous dibenzoyl peroxide with ditretbutyl peroxide or tert-butyl perbenzoate in various ratios. Then an electric discharge is produced in this volume, which is explosive in nature with large electrodynamic forces acting in all directions. At the same time, part of the hardening material 4 is introduced into the bottom and side walls of the well, strengthening them, and the level of hardening material occupies a position below the original. A drill auger is raised to a height (0.8-1.5) of the diameter of the well from the level of the hardening material formed after the first charge. Then, the above operations (lifting and discharge) are repeated until the well is filled to the full depth.

The following substances were used to implement the method: dibenzoyl peroxide GOST 14888-78, ditretbutyl peroxide TU 6-5-2026-86, tert-butyl perbenzoate TU 6-5-1997-85

Example 1. Piles were erected with a 10 m long drill screw, at the end of which a spark gap with a capsule was installed with the possibility of extension, containing a non-detonating mixture connected by a low-inductance cable to an electric-discharge station (capacitive energy storage) of 20 kJ, the outer diameter of which was 230 mm. As a supporting layer, dusty sand of medium density, not water-saturated, was used. After passing the projectile to a depth of 10 m, it was lifted to a height of 184 mm, which is 0.8 of the diameter of 230 mm, since it is this diameter that the well has, which is formed by a drill, and at the same time feed hardening material. After the drill stopped, it was rotated in the opposite direction to the drilling.

Hardening material was supplied until the absorption of the material ceased, which indicated the complete filling of the cavity under the drill. After that, a discharge was made to burn the non-detonating mixture by applying a high-voltage voltage pulse through an electric spark gap to form a camouflage cavity, which was subsequently filled with hardening material. In this case, as a non-detonating mixture, a mixture of a mixture of dibenzoyl peroxide and tert-butyl perbenzoate was used at a ratio of 50:50. The effectiveness of the non-detonating mixture used was judged by the volume of concrete consumed to fill the void formed by burning the mixture. The mass of the mixture and the volume of expendable concrete are presented in table. 1. Then the drill was lifted to a height of 184 mm, the discharge was repeated, while filling the vacated volume, and all operations were repeated until the well was completely filled 10 m. In this case, the pile has a diameter significantly exceeding the initial one obtained during drilling.

After the set of strengths, static tests of the manufactured piles were carried out, which showed the bearing capacity of the piles 85 tons.The expected bearing capacity of the piles when calculating by existing methods 45 tons. This indicates that the proposed method of construction of piles allowed to increase the bearing capacity of piles up to 40%.

It is recommended that these operations be continued until the entire soil layer has passed, after which they again change the direction of displacement of the lower end of the casing and the spark gap relative to each other in the well and repeat the previously described method operations until the pile shaft is completely manufactured. As a result, a stuffed pile with a widened heel with increased bearing capacity is manufactured.

Example 2. Carry out the construction of piles analogously to example 1, where as a non-detonating mixture using a mixture of dibenzoyl peroxide with tert-butyl perbenzoate at a ratio of 25:75. The mass of the non-detonating mixture and the volume of consumable concrete are presented in table. one.

Example 3. Carry out the construction of piles analogously to example 1, where as a non-detonating mixture using a mixture of dibenzoyl peroxide with ditretbutyl peroxide at a ratio of 50:50. The mass of the non-detonating mixture and the volume of consumable concrete are presented in table. one.

Example 4. Carry out the construction of piles analogously to example 1, where as a non-detonating mixture using a mixture of dibenzoyl peroxide with ditretbutyl peroxide at a ratio of 75:25. The mass of the non-detonating mixture and the volume of consumable concrete are presented in table. one.

The inventive method also allows to produce a printed pile with a widened heel in soils, where the stability of the walls of boreholes is not ensured, as well as in structurally unstable soils (silts, peat, water-saturated peat soils, etc.).

The effectiveness of the non-detonating mixtures used was determined by the volume of concrete consumed to fill the voids that are formed as a result of the combustion of various non-detonating mixtures given in Table. 1. As can be seen from the table. 1, when equal amounts of mixtures of 2-5 are burned, the volume of concrete consumed is several times greater than the volume of concrete squeezed by the prototype, due to the fact that mixtures 2-5 are used in pure form, and the prototype is used in the form of an aqueous solution. To achieve the desired effect, a larger amount of mixture 1 is required, which is impossible with certain dimensions of the container and space in the pile.

Claims (1)

A method of erecting a printed structure in the soil, including forming a well, supplying a hardening material to the well, installing a switching arrester electrodes connected to a source of pulsed electric discharges, exciting high-voltage electric discharges using an emitter, each high-voltage discharge being simultaneously supplied to the interelectrode the space of the emitter of a non-detonating exothermic mixture and its burning during a high-voltage electrochemical explosion, ayuschiysya in that an exothermic knock-free mixture is fed into the interelectrode space with a mixture of diterbutylperoxide dibenzoyl peroxide or dibenzoyl peroxide with tretbutilperbenzoatom mixture in proportions in the mixtures (1: 1) - (3: 1).

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