CN112609708A

CN112609708A - Optimized connection method for underground continuous wall and secant pile

Info

Publication number: CN112609708A
Application number: CN202011465137.6A
Authority: CN
Inventors: 严融; 陈益贵; 罗云峰; 向春; 张标; 顾欢
Original assignee: Shanghai Foundation Engineering Group Co Ltd
Current assignee: Shanghai Foundation Engineering Group Co Ltd
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2021-04-06

Abstract

The invention relates to an optimized connection method of an underground continuous wall and an occlusive pile, which comprises the following steps of firstly, adding or utilizing a pre-digging section at a corner as a grooving part of the underground continuous wall; then, constructing the underground continuous wall at the joint and pouring concrete together with the pre-digging section; and finally, directly cutting the vegetable concrete of the pre-dug section of the ground wall during the meat-bearing pile construction of the secant pile, and forming a secant joint with the underground continuous wall after the meat-bearing pile is formed. The optimization method provided by the invention not only ensures the problem that the connecting section is difficult to process, but also optimizes the joint to form a U-shaped occlusion form, and more effectively ensures the water stopping effect of the weak part of the joint. The underground diaphragm wall, the pre-dug sections and the secant plain piles are constructed firstly in the process, so that the concrete pouring time of the pre-dug sections on one sides of the two sides of the plain piles and the concrete pouring time of the plain piles on one side are basically consistent, the strength of the plain concrete cut on the left side and the right side is basically consistent when the rotary excavating equipment is adopted for forming holes in the secant plain piles, the hole forming drilling can be effectively carried out, the construction efficiency is improved, and the economic cost can be further reduced.

Description

Optimized connection method for underground continuous wall and secant pile

Technical Field

The invention relates to an underground engineering construction process, in particular to a construction process when double-layer steel reinforcement cage sections cannot be quickly connected in construction.

Background

The foundation pit adopts different support forms according to the consideration of peripheral environment, the condition of structures, the safety level of the foundation pit, the economic consideration of construction units and the like, particularly, an underground continuous wall is adopted at a common subway protection section in a Shenzhen region, and other support surfaces adopt a secant pile support form. Two common methods are as follows: considering that the underground continuous wall has a large reinforcement ratio, plain piles of the secant piles have no reinforcement configuration (but bored piles have reinforcements), but conventional underground continuous wall grooving equipment only needs a grooving machine, for example, firstly constructed plain piles of the secant piles or bored piles (namely a supporting form of row piles and inter-pile rotary spraying) and then constructed underground continuous wall, at the moment, the formed plain piles need to be seceded by the underground continuous wall, so that the requirement of the equipment needs to adopt the grooving machine, the economic cost is greatly increased, meanwhile, the stress on two sides of the underground continuous wall is uneven, and the verticality deviation in the grooving process is easily generated, so that the treatment method is not easy to realize basically; if the underground continuous wall is constructed firstly and then the secant pile element pile or the high-pressure jet grouting pile is constructed, the formed underground continuous wall and the reinforcement cage thereof need to be damaged, the structural stress can be greatly influenced, and the water leakage condition is easily aggravated; two high-pressure jet grouting piles are additionally arranged at the joint to ensure the water stopping effect, so that the connection mode of the high-pressure jet grouting piles is optimized to solve the problem.

Disclosure of Invention

The invention aims to provide an optimized connection method for an underground continuous wall and an occlusive pile, and provides a specific and effective optimized connection method aiming at solving the problems that the supporting stress at the weak joint of the underground continuous wall and the occlusive pile is reduced and the water leakage condition is aggravated in the absence of a proper connection mode at present.

In order to realize the construction purpose, the invention adopts the following scheme:

a method for optimally connecting an underground continuous wall and an occlusive pile comprises the following steps of firstly, adding or utilizing a pre-digging section at a corner as a grooving part of the underground continuous wall; then, constructing the underground continuous wall at the joint and pouring concrete together with the pre-digging section; and finally, directly cutting the vegetable concrete of the pre-dug section of the ground wall during the meat-bearing pile construction of the secant pile, and forming a secant joint with the underground continuous wall after the meat-bearing pile is formed.

Further, in the ground wall grooving stage, the distance of the pre-digging section is controlled according to the distance between the underground continuous wall and the meat-bearing pile of the secant pile or the cast-in-situ bored pile, so that the subsequent cutting of the pre-digging section of the vegetable concrete of the secant pile construction machine is facilitated.

Further, in the construction stage of the secant pile, the meat-bearing pile and the underground continuous wall form a U-shaped secant form after being formed into a pile, and the water stopping effect of the weak part of the joint is effectively ensured.

Furthermore, when the underground continuous wall at the construction joint is cast with concrete together with the pre-digging section, the pre-digging section only casts concrete without reinforcing bars.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention can effectively reduce the construction difficulty of the connection part of the ground wall and the secant pile, accelerate the construction efficiency and obviously improve the water stopping effect of the wall and pile joints.

2. The optimized connection mode formed by the invention is a construction measure which can be relatively fast and convenient, the pre-digging section is added to offset the plain pile of the secant pile, machinery such as a slot milling machine is not needed, and the construction cost is reduced.

Drawings

FIG. 1 is a schematic flow chart of the construction method of the present invention;

FIGS. 2 to 5 are schematic diagrams of the optimized construction process of the ground wall and secant pile connecting joint.

Detailed Description

The invention is further illustrated with reference to the following figures and specific examples. These examples are given solely for the purpose of illustration and are not intended to limit the scope of the invention, which is to be given the full breadth of the present disclosure, and any variations or modifications within the skill of the art after reading the teachings herein, may be made, and such equivalents are intended to fall within the scope of the invention as defined in the claims appended hereto.

As shown in fig. 1 to 5, the present embodiment provides an optimized connection method for an underground continuous wall and a bite pile, which specifically includes the following steps:

firstly, adding or utilizing a pre-dug section 1 at a corner as a grooving part 2 of an underground continuous wall (the distance of the pre-dug section 1 is controlled according to the distance of a meat pile or a bored pile of the underground continuous wall and an occluding pile), and the figure 2 is shown; then, the underground continuous wall of the construction joint is cast with concrete 3 together with the pre-digging section (the pre-digging section only casts concrete without reinforcing bars), as shown in figure 3; and finally, directly cutting the vegetable concrete 4 of the pre-dug section of the ground wall during the meat-pile construction of the secant pile, as shown in figure 4, and forming a secant joint 5 with the underground continuous wall after the meat-pile is formed, as shown in figure 5.

Further, in the groove forming stage of the ground wall, the distance of the pre-digging section is controlled according to the distance between the underground continuous wall and the meat-bearing pile of the secant pile or the drilling cast-in-place pile, so that the subsequent cutting of the pre-digging section of the vegetable concrete of the secant pile construction machine is facilitated.

Further, in the construction stage of the secant pile, the vegetable concrete of the pre-dug section of the ground wall is directly cut when the secant pile is constructed by using the secant pile, and the meat pile and the underground continuous wall form a U-shaped secant form after being formed into the pile, so that the water stop effect of the weak part of the joint is effectively ensured, and the water stop effect is shown in figure 5.

The invention can solve the problems that the supporting stress at the weak joint is reduced and the water leakage condition is aggravated when the ground wall is connected with the secant pile, effectively reduces the construction difficulty at the connection part of the ground wall and the secant pile and accelerates the construction efficiency. The pre-digging section added in the construction counteracts the plain pile of the secant pile, and machines such as a slot milling machine and the like are not needed, so that the construction cost is reduced, the construction method is quick and convenient, and the popularization is easy.

Claims

1. An optimized connection method of an underground continuous wall and an occlusive pile is characterized in that: firstly, adding or utilizing a pre-digging section at a corner as a grooving part of an underground continuous wall; then, constructing the underground continuous wall at the joint and pouring concrete together with the pre-digging section; and finally, directly cutting the vegetable concrete of the pre-dug section of the ground wall during the meat-bearing pile construction of the secant pile, and forming a secant joint with the underground continuous wall after the meat-bearing pile is formed.

2. The method for optimally connecting the underground continuous wall and the occlusive piles according to claim 1, wherein the method comprises the following steps: and in the ground wall grooving stage, the distance of the pre-dug section is controlled according to the distance between the underground continuous wall and the meat-bearing pile of the secant pile or the drilled cast-in-place pile, so that the subsequent cutting of the pre-dug section of the plain concrete of the secant pile construction machine is facilitated.

3. The method for optimally connecting the underground continuous wall and the occlusive piles according to claim 1, wherein the method comprises the following steps: in the construction stage of the secant pile, the meat-bearing pile and the underground continuous wall form a U-shaped secant form after being formed into the pile, and the water stopping effect of the weak part of the joint is effectively ensured.

4. The method for optimally connecting the underground continuous wall and the occlusive piles according to claim 1, wherein the method comprises the following steps: and when the underground continuous wall at the construction joint and the pre-digging section are used for pouring concrete together, the pre-digging section is only used for pouring concrete without reinforcing bars.