CN106592599B

CN106592599B - Device for rapidly controlling foundation pit displacement and construction method

Info

Publication number: CN106592599B
Application number: CN201611072038.5A
Authority: CN
Inventors: 程明进; 杨志
Original assignee: Shanghai Foundation Engineering Group Co Ltd
Current assignee: Shanghai Foundation Engineering Group Co Ltd
Priority date: 2016-11-29
Filing date: 2016-11-29
Publication date: 2020-03-27
Anticipated expiration: 2036-11-29
Also published as: CN106592599A

Abstract

The invention relates to a device for quickly controlling the displacement of a foundation pit and a construction method thereof.A steel support is arranged at two ends of an enclosing purlin paved by H-shaped steel at the bottom of the foundation pit, and after corresponding prestress is applied through a stress application rod piece, three triangular wedge blocks are respectively driven into two sides of a gap between a head plate of the steel support and the enclosing purlin at the bottom of the foundation pit in the horizontal direction, so that the steel support and the enclosing purlin have the applied prestress. And the steel supports are placed step by step at the position of the whole substrate, which avoids the engineering pile, so that the quick control displacement device is formed. Compared with the traditional foundation pit supporting mode, the method can well control the horizontal displacement of the foundation pit in the period from the excavation of the foundation pit to the pouring of the base plate to the achievement of the corresponding strength. The invention can quickly control the horizontal displacement of the foundation pit within the time from excavation of the foundation pit to pouring of the substrate to pouring of the bottom plate and reaching the corresponding strength.

Description

Device for rapidly controlling foundation pit displacement and construction method

Technical Field

The invention relates to a foundation pit displacement control device in deep foundation pit construction, in particular to a displacement control device and a construction method of a deep foundation pit which is located in a subway protection range and has a complex peripheral environment and strict requirements on the horizontal displacement of foundation pit excavation.

Background

The invention discloses a quick displacement control device for a foundation pit, which is used for quickly controlling the displacement of the foundation pit, and the construction of the deep foundation pit is underground concealed engineering, so that certain risks exist, particularly when a subway or a building is approached, a favorable support system is formed at the bottom of the foundation pit when the foundation pit is excavated, the exposure time of the bottom of the foundation pit is reduced, and the horizontal displacement of the foundation pit can be effectively controlled.

The construction process of the existing similar engineering mainly comprises the following steps: pit bottom reinforcement, warehouse division excavation, block excavation, reinforcement cushion layer and the like. However, the above construction techniques all have the following problems:

the pit bottom reinforcement increases the construction cost and the construction period; the skip excavation and the block excavation are not suitable for small foundation pits with narrow places and complex surrounding environments; the reinforced cushion layer has low initial strength of concrete in the first few days just before pouring, and cannot form an effective force transmission system.

Disclosure of Invention

The invention aims to provide a device and a construction method for quickly controlling the displacement of a foundation pit.

In order to achieve the purpose, the technical scheme of the invention is as follows: a device for rapidly controlling the displacement of a foundation pit is arranged at the base position before a cushion layer of the foundation pit is poured and comprises a steel support, a stress application rod piece and triangular wedge blocks, wherein two ends of the steel support are respectively arranged at two sides of an enclosing purlin paved by H-shaped steel at the bottom of the foundation pit, and after corresponding prestress is applied through the stress application rod piece, three triangular wedge blocks are respectively driven into two sides of a gap between a head sealing plate of the steel support and the enclosing purlin at the bottom of the foundation pit in the horizontal direction, so that the steel support and the enclosing purlin have applied prestress.

The boosting rod piece consists of a square tube and a jack, steel plates are welded at two ends of the square tube in a sealing mode, the jack is welded at one end of the square tube, and two lifting lugs are welded on the square tube in the length direction; a steel plate is welded between the square pipe and the jack and used for increasing the stress area.

The steel support comprises H shaped steel and a head plate, the head plate is welded at two ends of the H shaped steel, and the head plate is formed by welding a head steel plate and four triangular steel plates.

A construction method adopting a device for rapidly controlling foundation pit displacement comprises the following specific steps: after the foundation pit is excavated to the bottom, placing a steel support in an enclosing purlin frame laid by H-shaped steel at the bottom of the foundation pit, and then hoisting and placing the steel support platform to a corresponding position through a crane; then, a crane hangs the stress application rod to the side of the steel support through a platform, corresponding prestress is applied through a jack on the stress application rod, and then the triangular wedge blocks are respectively driven into blocks from two sides of a gap between the head plate of the steel support and the enclosing purlin at the bottom of the foundation pit in the horizontal direction, so that the prestress is applied in place between the steel support and the enclosing purlin at the bottom of the foundation pit; then the jack on the stress application rod piece is loosened; and continuously repeating the steps to completely prestress all the steel supports.

The invention has the beneficial effects that: compared with the traditional foundation pit supporting mode, the method can well control the horizontal displacement of the foundation pit in the period from the excavation of the foundation pit to the pouring of the base plate to the corresponding strength. The invention can quickly control the horizontal displacement of the foundation pit within the time from excavation of the foundation pit to pouring of the substrate to pouring of the bottom plate and reaching the corresponding strength.

The invention processes a stress application rod piece, a steel support and a triangular wedge block outside a field, then quickly hoists the stress application rod piece, the steel support and the triangular wedge block by a crane, and places the stress application rod piece, the steel support and the triangular wedge block to the position of a base to form an integral force transmission system, thereby achieving the effect of controlling the horizontal displacement of a foundation pit. Therefore, the device and the construction method can realize the effect of quickly controlling the displacement of the foundation pit after the foundation pit is excavated to the bottom.

Drawings

FIG. 1 is a schematic view of the apparatus and construction method of the present invention;

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is a schematic view of a steel support;

FIG. 5 is a schematic view of a steel support and head plate construction;

FIG. 6 is a left side elevation view of FIG. 5;

FIG. 7 is a perspective view of a force applying rod;

FIG. 8 is a schematic plan view of a force bar;

FIG. 9 is a partial enlarged view of the lifting lug of FIG. 8;

FIG. 10 is a left side elevation view of the shackle of FIG. 9;

FIG. 11 is a front view of a triangular wedge;

fig. 12 is a left side view of fig. 11.

Detailed Description

The invention is further described with reference to the following figures and examples.

As shown in fig. 1 to 12, the device for rapidly controlling the displacement of the foundation pit is arranged at the base position before the bedding layer of the foundation pit is poured, and comprises a steel support 1, a stressing rod piece 2, an H-shaped steel 3 and a triangular wedge block 4. Two ends of a steel support 1 are respectively arranged on two sides of an enclosing purlin paved by H-shaped steel 3 at the bottom of a foundation pit, and after corresponding prestress is applied through a stress application rod piece 2, three triangular wedge blocks 4 (figures 11 and 12) are respectively driven into two sides of a gap between a head plate 6 of the steel support 1 and the enclosing purlin at the bottom of the foundation pit in the horizontal direction, so that the steel support 1 and the enclosing purlin have the applied prestress.

As shown in fig. 7, 8, 9 and 10, the stress application rod member is composed of a

square pipe

9, 2

lifting lugs

11, 2 steel plates 12 and a jack 10; the two ends of the square tube 9 are hermetically welded by steel plates 12, the jack 10 is welded at one end, full welding is adopted, and the welding line is not less than 8 mm; the stress application rod piece 2 is welded at one end of the square tube 9 through a

jack

10, and 2 lifting lugs 11 are welded in the middle of the square tube 9, so that a crane 13 can conveniently lift the stress application rod piece. The jacks 10 are only arranged at one end of the square pipe 9, one steel plate 12 is welded between the jacks 10 for increasing the stress area, and the other end of the jacks is welded by the steel plate 12, so that the prestress is conveniently applied between the stress application rod 2 and the enclosing purlin. The position of the lifting lug 11 is on the central line of the square pipe 9, the specific position is determined by calculating the gravity center position of the lifting lug, and the horizontal state of the stress application rod piece is kept when the crane 13 is hoisted conveniently.

As shown in fig. 4, 5 and 6, the steel support is composed of H-

shaped steel

3 and 2 head plates 6, the head plates 6 are welded by a head steel plate 8 which is one circle larger than the H-shaped steel and 4 triangular steel plates 7, the head steel plate 8 is welded on the H-shaped steel 3, the triangular steel plates 7 are positioned at four corners of the H-shaped steel 3 to four corners of the head steel plate 8 and are all fully welded, and the welding line is not less than 8 mm.

A construction method adopting a device for rapidly controlling foundation pit displacement comprises the following specific steps: after the foundation pit is excavated to the bottom, firstly, determining a frame of a device for quickly controlling the displacement of the foundation pit, and then placing 1 steel support to a corresponding position by 13 cranes; then, the crane 13 is hung beside the steel support 1 through a platform crane stress application rod member 2, and corresponding prestress is applied through a jack 10 on the stress application rod member 2; then 3 triangular wedges 4 are respectively driven into two sides of a gap between a head sealing plate 6 of the steel support 1 and the enclosing purlin in the horizontal direction, and prestress is applied in place between the steel support 1 and the enclosing purlin; then the jack 10 on the stress application rod 2 is loosened; continuously repeating the steps to apply prestress to all the steel supports 1 in the field; and then pouring a cushion layer in the site, pouring all the whole device into the cushion layer, and then constructing the bottom plate and the main body structure.

Claims

1. The utility model provides a quick control foundation ditch displacement device lays the basement position before the bed course of foundation ditch is pour, including steel shotcrete (1), afterburning member spare (2), triangle-shaped voussoir (4), its characterized in that: two ends of the steel support (1) are respectively arranged at two sides of an enclosing purlin paved by H-shaped steel (3) at the bottom of a foundation pit, and after corresponding prestress is applied through a stress application rod piece (2), three triangular wedge blocks (4) are respectively driven into two sides of a gap between a head sealing plate (6) of the steel support (1) and the enclosing purlin at the bottom of the foundation pit in the horizontal direction, so that the applied prestress is formed between the steel support (1) and the enclosing purlin; the stress application rod piece (2) is composed of a square tube (9) and a jack (10), steel plates (12) are welded at two ends of the square tube (9) in a sealing mode, the jack (10) is welded at one end of the square tube, and two lifting lugs (11) are welded on the square tube (10) in the length direction.

2. The device for rapidly controlling foundation pit displacement according to claim 1, wherein: the steel support (1) is composed of H-shaped steel (3) and two end sealing plates (6), the end sealing plates (6) are welded at two ends of the H-shaped steel (3), and the end sealing plates (6) are formed by welding an end sealing steel plate (8) and four triangular steel plates (7).

3. A construction method for rapidly controlling the foundation pit displacement device according to claim 1 or 2 is characterized by comprising the following specific steps: after the foundation pit is excavated to the bottom, placing the steel support (1) in an enclosing purlin frame paved by H-shaped steel at the bottom of the foundation pit, and then lifting and placing the steel support (1) to a corresponding position through a crane (13); then, a crane (13) is hung beside the steel support (1) through a platform crane stressing rod piece (2), corresponding prestress is applied through a jack (10) on the stressing rod piece (2), and then three triangular wedge blocks (4) are respectively driven into two sides of a gap between a head sealing plate (6) of the steel support (1) and an enclosing purlin at the bottom of the foundation pit in the horizontal direction, so that the prestress applied between the steel support (1) and the enclosing purlin at the bottom of the foundation pit is ensured to be in place; then the jack (10) on the stress application rod piece (2) is loosened; and continuously repeating the steps to completely prestress all the steel supports (1).