RU1794192C - Method for constructing pits - Google Patents

Abstract

Usage: in the construction of pits for buildings and underground structures. SUMMARY OF THE INVENTION: I-beams are placed in a well with a charge of explosives attached to the bottom for a length equal to the depth of the pit. The side flanges of the I-beams direct the products of the explosion towards a free borehole. After the explosion, the panel is placed in the resulting container, rigidly fixing it between the I-beams. 3 ill.

Description

The invention relates to the construction of pits for buildings and structures for various purposes, created by the method of wall in the ground, and can be used in the construction of, for example, the walls of the basement of buildings in subsidence soils

When erecting foundations in an open foundation pit, the work project provides for the following activities: tearing out the pit, securing the walls of the pit, draining it, preparing the foundation, arranging the foundations and backfilling the sinuses with proper sealing. To ensure the normal conduct of work on the installation of foundations erected in open pits, it is necessary to exclude the possibility of the collapse of their flanges.

The stability of the walls of the pit is ensured by giving them appropriate slopes or using special fasteners.

The increasing volume of earthwork is associated with the need to introduce new progressive methods of constructing foundation pits into construction practice. One such method is a method, conditionally referred to as a wall in the ground. There is a method of constructing the foundations of a wall in the ground, which consists in constructing the bearing walls of underground rooms by extracting deep and narrow trenches with vertical walls under a clay solution, followed by laying monolithic or precast concrete and reinforced concrete in a trench (1, Fig. 56, p. 109) . The clay mortar protects the walls of the trenches from collapse, the depth of which can reach 35 m. When installing a monolithic concrete or reinforced concrete wall, the concrete mixture is laid in a trench by the method of vertically moving pipes (VPT). When laying concrete, the clay mud is displaced and gravity poured into the next trench trench, where soil is being developed

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or pumping the solution for later use.

When applying this method in subsidence soils, collapse of the vertical walls of the soil from the action of clay water will be observed, which will lead to an increase in concrete consumption. Fallen out soil settled at the bottom of the trench reduces the depth of the trench and will require additional funds and time to bring the trench to the design depth. All this leads to an increase in the cost of construction of the pit.

In some cases, the deep foundation foundation constructed by the wall in the ground method is arranged by drilling and filling concrete wells with concrete, obtained as follows. Under the protection of a solution of bentonite clay, first two wells are drilled in increments of one and a half diameters (2, Fig. 11.45, p. 240). Then they are filled with concrete mixture and at the start of setting concrete, but before they gain significant strength, a third well is drilled between them, followed by filling with concrete mixture, etc. until the intersecting wells gradually form a wall of the required length and depth.

With this method, a large amount of drilling work and a longer pit construction are observed. In addition, clay water, penetrating the soil, sharply reduces its strength

properties and stability of well walls. This phenomenon is especially strongly observed in soils classified as type II by time. This leads to an increase in the cost of work and a decrease in labor productivity.

There is a known method of securing a foundation pit with a collapsible wall, which includes dispersing wells along the contour of the pit during the formation of compacted soil around their area and extracting the surrounding soil. Wells are tamped at a distance from one another, equal to the sum of the width of the well and twice the thickness of the compacted soil. This method increases the stability of the walls of the recess, but is very labor intensive, the inability to control the quality of the seal and a significant duration.

There is a method of creating a reinforced support array in the soil, which is the formation of wells, cutting through these wells of cracks in the soil | using a jet of liquid and filling up 0

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lei as they are cut through with concrete mixture and the reinforcement cage is inserted into it.

The disadvantages of this method are:

- the need to have powerful additional water sources and sedimentation tanks for pulp formation;

- the complexity, and sometimes the inability to carry out work on the construction of pits in the winter;

- when working in subsiding soils, undesirable subsidence of the soil appears, which is the reason for the loss of stability of the sides of the pit;

- For fastening of the boards that have lost stability, additional fastening is required, which leads to the consumption of concrete and an increase in the construction time.

The prototype of the technological implementation, the closest to the proposed invention, is a method of constructing a wall in the ground (ave. St. No. 1553692 (51) 5 E 21 D 1/00), including drilling wells along the wall, installation in part of the wells charges and their subsequent filling with concrete mix .. The ultimate conjugation of the wells is obtained when explosives are blasted with the release of detonation products through unfilled wells. Before blasting the charges, pressurize the concrete mixture to a value equal to the pressure of the detonation products at the wellhead, and release the detonation products after reaching equal pressures in all uncharged wells until the concrete mixture comes to the surface.

In this method, the installation of special equipment increases the production time, since the walls of the pit are not sealed, it is necessary to increase the size of the retaining wall, which leads to an increase in material consumption. In addition, water from concrete is sucked away by subsiding soils, which leads to a change in their structure and increases their subsidence.

The aim of the invention is to increase the stability of the walls of the basin in subsidence soils by compaction with a directed explosion. This goal is achieved by drilling wells along the excavation path, filling with fasteners and 8 V charges and blasting, for which I-beams are placed in the well through one, the side flanges of which are parallel to the walls of the excavation and serve to direct the explosion products in the direction of a free well, and install charges В В on the racks of I-beams with

both sides to a length equal to the depth of the pit after the explosion of which reinforced concrete panels are lowered into the cavity formed, the protrusions of which are placed between the side shelves of the I-beams.

A sign - the use of strictly directed explosion products to harden the walls of the foundation pit in subsiding soils and at the same time create a cavity for accommodating fasteners - is not known.

A sign - the use of I-beam shelves for guiding explosion products and fixing reinforced concrete panels - is not known.

In FIG. 1 shows a longitudinal section through wells with I-beams placed in them with explosive charges; see 2 - the same, a top view; in Fig.3 is a diagram of the mounting of the pit with reinforced concrete panels, top view ..

In the boreholes 1, I-beams of metal 2 are placed with explosive charges 3 attached on both sides of the strut 4 to a length equal to the depth of the pit. The side flanges 5 of the I-beams 2 serve as guides of the explosion products towards the free well 6, in order to obtain a cavity 7. In the resulting cavity 7 after

the explosion place a reinforced concrete panel, the protrusions which are placed between the side shelves of the I-beams 2.

The proposed method is implemented as follows.

Wells 1 are drilled along the wall route, in which metal I-beams 2 are placed through one, two explosive charges 3 are attached on both sides, length

which is equal to the depth of the pit. In the event of an explosion, the side flanges 5 of the I-beam will direct the explosion products toward the side of the free well 6. The explosion products directed towards each other

form a cavity, the side walls of which are sealed by an explosion. A reinforced concrete panel is installed in the cavity formed after the explosion, which is fixed by I-metal

beams.

The effectiveness of the construction of pits in subsidence soils by the wall A soil method is achieved by reducing the construction time, since the process of cavity formation, soil compaction and placement of load-bearing structures are combined in time. Due to compaction of soils, pressure on the retaining wall is reduced, which actually reduces its thickness.

Claims (1)

SUMMARY OF THE INVENTION A method of forming pits, including drilling along a path of a pit of wells, installing them through one charge B B, blasting and securing it, and so that, in order to increase the stability of the walls of the pit, subsidence soils due to their compaction with a directed explosion, explosive charges are poured on racks of I-beams from two sides to a length equal to the depth of the pit, which are then lowered into the wells, placing the side shelves parallel to the walls of the pit, while fixing is carried out in the cavity formed after the explosion by lowering the reinforced concrete panels, the protrusions of which are placed between the side shelves of the I-beams . Figure 1 Ph g, t / / /// S / S / SSL / Ai S / S /// /// /// /// /// /// S / S / SS Y // ///