CN110004919B

CN110004919B - Foundation pit enclosure construction method used in pipeline influence range

Info

Publication number: CN110004919B
Application number: CN201910360990.2A
Authority: CN
Inventors: 尚春阳; 李孟章; 宋寿兵; 赵立军; 张�廷; 许东晓; 郝红伟; 蒲赵蔡; 赵硕
Original assignee: Railway Tenth Group Northwest Engineering Co ltd
Current assignee: Railway Tenth Group Northwest Engineering Co ltd
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2020-11-17
Anticipated expiration: 2039-04-30
Also published as: CN110004919A

Abstract

A foundation pit enclosure construction method used in a pipeline influence range comprises the following steps: respectively excavating deep grooves along the outer sides of two sides of a foundation pit to be excavated, wherein one side of each deep groove, which is far away from the foundation pit, is a slope; arranging fender posts in the deep groove at line gaps, arranging a pile top crown beam by taking the fender posts as supports, and reserving a steel bar joint at the bottom of the pile top crown beam; arranging a retaining wall on the surface of the slope; excavating foundation pits in layers, and arranging a retaining wall between every two retaining piles; and after the foundation pit is excavated, backfilling earthwork between the retaining wall and the enclosure wall. Through building retaining wall and enclosure wall, consolidated foundation ditch both sides earthwork, the quantity that sets up of foundation pile when reducing pile bolck crown beam construction makes the pipeline with can the foundation ditch enclosure setting of interaction, has avoided changing the original pipeline, has effectively reduced the engineering volume to easy operation can also effectually improve foundation ditch enclosure structure overall stability, can accelerate the construction progress, practices thrift construction cost, to resident's water, advantage such as little influence such as power consumption, gas communication.

Description

Foundation pit enclosure construction method used in pipeline influence range

Technical Field

The invention relates to the technical field of foundation pit bracing, in particular to a foundation pit bracing construction method used in a pipeline influence range.

Background

With the development of rail transit construction in China, the proportion of subway engineering is larger and larger, pile foundation construction is particularly important in subway engineering, subway station construction is generally located in the center of a city, underground pipelines on the ground of the center of the city are complicated, pipelines are difficult to change and long in time span, and large machinery cannot play a role in the environment.

The traditional construction method is approximately a cast-in-situ bored pile construction method: pipeline excavation → pipeline relocation → pile foundation construction → structure construction → pipeline relocation. The existing foundation pit support method needs to densely arrange pile foundations, so that pipelines cannot penetrate through gaps between the pile foundations and need to be changed. The pipeline relocation construction period has large cost influence and large engineering quantity, and the pipeline relocation involves operations such as water, electricity, gas, communication and the like, so that the pipeline relocation construction period has large influence on the surrounding people and has more uncontrollable factors. Therefore, the technical scheme provides the foundation pit enclosure construction method which has larger distance between pile foundations and can be interactively arranged with the pipeline, and the original pipeline is prevented from being changed.

Disclosure of Invention

The invention aims to provide a foundation pit enclosure construction method used in a pipeline influence range, which can enlarge the distance between foundation piles during foundation pit enclosure, enable pipelines to be arranged between the foundation piles in an inserting mode and reduce pipeline relocation.

The invention provides a foundation pit enclosure construction method used in a pipeline influence range, which comprises the following steps:

step 1, respectively excavating deep grooves along the outer sides of two sides of a foundation pit to be excavated, excavating the deep grooves until pipelines in earthwork on two sides of the foundation pit are exposed, and arranging slope surfaces on one sides, far away from the foundation pit, of the deep grooves.

And 2, arranging fender posts in the deep groove at the line clearance, arranging a pile top crown beam by taking the fender posts as supports, and reserving a steel bar joint at the bottom of the pile top crown beam.

And step 3, arranging a retaining wall on the surface of the slope.

And 4, excavating the foundation pit in a layered mode, and arranging a retaining wall between every two retaining piles.

And 5, after the foundation pit is excavated, backfilling earthwork between the retaining wall and the enclosure wall.

Preferably, the construction step in step 3 is as follows:

step 3.1, excavating a wall surface which forms an included angle with the enclosure pile in the vertical direction on the outer side of the enclosure pile, and arranging a reinforcing mesh on the wall surface;

step 3.2, nailing the reinforced soil nails into the earthwork perpendicular to the slope surface, and fixedly connecting the other ends of the reinforced soil nails with the reinforced net sheets;

and 3.3, spraying concrete on the reinforcing mesh.

Preferably, the construction method of the enclosure wall in the step 4 comprises the following steps:

step 4.1, a construction rib is arranged between every two adjacent fender piles on the same side of the foundation pit, the construction rib is of a net structure, and the construction rib is fixedly connected with the fender piles;

and 4.2, erecting formworks on two sides of the construction ribs, pouring concrete in the formworks, and removing the formworks after the concrete reaches the designed strength.

Preferably, the angle between the retaining wall in the step 3 and the vertical direction of the fender post is 15 degrees.

Preferably, the thickness of the sprayed concrete on the reinforcing mesh is 10 cm.

Preferably, the wall body of the enclosure wall extends into the earthwork at the bottom layer of the foundation pit by less than 1 m.

Preferably, the construction rib is fixedly connected with the reserved steel bar joint at the bottom of the crown beam.

Preferably, the construction bar is in two layers, two layers of reinforcing mesh being arranged opposite each other and both being fixed to the enclosure pile.

Compared with the prior art, the foundation pit enclosure construction method for the pipeline within the influence range has the following beneficial effects:

through building the retaining wall and the enclosure wall, the earthwork on two sides of the foundation pit is reinforced, the number of the foundation piles is reduced, the retaining wall and the enclosure wall can be arranged around the pipeline in a surrounding mode according to needs, the pipeline and the foundation pit enclosure can be arranged in an interactive mode, the change of the original pipeline is avoided, the engineering quantity is effectively reduced, the method is simple and easy to operate, the overall stability of the foundation pit enclosure structure can be effectively improved, the construction progress can be accelerated, the construction cost is saved, and the method has the advantages of being small in influence on water, electricity, gas communication and the like of residents.

Drawings

FIG. 1 is a schematic view of a foundation pit enclosure construction method for use within the pipeline influence range provided by the present invention.

FIG. 2 is a schematic view of a retaining wall used in a foundation pit support construction method within a pipeline influence range.

FIG. 3 is a top view of a retaining wall for a foundation pit support construction method within the pipeline influence range.

Description of the main Components

In the figure: 1. a crown beam; 2. reinforcing steel bar soil nails; 3. reinforcing mesh sheets; 4. a retaining wall; 5. an enclosure wall; 6. a slope surface; 7. a fender pile; 8. a pipeline; 9. and (5) constructing ribs.

Detailed Description

The present invention is described in detail below with reference to the attached drawing figures. As shown in the attached drawings 1 to 3, a foundation pit enclosure construction method used in a pipeline influence range comprises the following steps:

step 1, respectively excavating deep grooves along two sides of a foundation pit to be excavated, excavating the deep grooves until pipelines 8 in earthwork on two sides of the foundation pit are exposed, and arranging a slope surface 6 on one side of the deep grooves far away from the foundation pit.

And 2, arranging a fender post 7 in the gap of the pipeline 8 in the deep groove, arranging a pile top crown beam 1 by taking the fender post 7 as a support, and reserving a steel bar joint at the bottom of the pile top crown beam 1.

And 3, paving a steel bar mesh 3 on the surface of the slope 6.

And 4, nailing the reinforced soil nails 2 into the earthwork along the direction vertical to the slope surface 6, and welding the other ends of the reinforced soil nails on the reinforced mesh 3.

And 5, spraying concrete on the reinforcing mesh 3.

And 6, arranging reinforcing steel bars between every two fender posts 7 on the same side of the foundation pit according to the horizontal direction and the vertical direction, and binding the crossed positions of the reinforcing steel bars by using iron wires to form a structural rib 9.

And 7, drilling holes at the opposite sides of every two guard piles 7 at the same side of the foundation pit, inserting reinforcing steel bars in the horizontal direction of the structural ribs 9 into the holes, and fixing the structural ribs 9 on the guard piles 7.

And 8, erecting formworks on two sides of the construction ribs 9, pouring concrete in the formworks, and removing the formworks after the concrete reaches the designed strength.

And 9, excavating the foundation pit in layers, arranging one enclosure wall 5 on each layer excavated in the foundation pit, welding the enclosure walls together through vertical reinforcing steel bars, welding the vertical reinforcing steel bars of the uppermost enclosure wall 5 with the reserved reinforcing steel bar joints at the bottom of the pile top crown beam 1, and penetrating the lowermost enclosure wall 5 into the soil below the bottom layer of the foundation pit by 1 meter.

And 10, after the foundation pit is excavated, backfilling earthwork between the retaining wall 4 and the enclosure wall 5.

According to the foundation pit enclosure construction method for the pipeline influence range, earth on two sides of a foundation pit is reinforced by building the retaining wall and the enclosure wall, the number of the foundation piles during pile top crown beam construction is effectively reduced, the retaining wall and the enclosure wall can be arranged around the pipeline in a surrounding mode according to needs, the pipeline and the foundation pit enclosure can be arranged in an interactive mode, the pipeline is prevented from being changed, the engineering quantity is effectively reduced, the method is simple and easy to operate, the overall stability of the foundation pit enclosure structure can be effectively improved, the construction progress can be accelerated, the construction cost is saved, and the method has the advantages of being small in influences on water, electricity and gas communication of residents and the like.

Claims

1. A foundation pit support construction method used in a pipeline influence range is characterized by comprising the following steps:

step 1, respectively excavating deep grooves along the outer sides of two sides of a foundation pit to be excavated, excavating the deep grooves until pipelines (8) in the earthwork are exposed, and arranging a slope (6) at one side of the deep grooves, which is far away from the foundation pit;

step 2, arranging fender posts (7) in the deep groove at intervals of pipelines (8), arranging a pile top crown beam (1) by taking the fender posts (7) as supports, and reserving a steel bar joint at the bottom of the pile top crown beam (1);

step 3, arranging a retaining wall (4) on the surface of the slope (6);

step 4, excavating foundation pits in layers, and arranging a retaining wall (5) between every two retaining piles (7) at the same time;

and 5, after the foundation pit is excavated, backfilling earthwork between the retaining wall (4) and the enclosure wall (5).

2. The method of claim 1 for the construction of a foundation pit enclosure within the influence of the pipeline, wherein the method comprises the following steps: the construction step of the step 3 is as follows:

step 3.1, arranging a steel bar mesh (3) on the slope;

step 3.2, the reinforced soil nails (2) are nailed into the earthwork along the direction vertical to the slope surface (6), and the other end of the reinforced soil nails is fixedly connected with the reinforced net piece (3);

and 3.3, spraying concrete on the reinforcing mesh (3).

3. The method of claim 1 for the construction of a foundation pit enclosure within the influence of the pipeline, wherein the method comprises the following steps: the construction method of the enclosure wall (5) in the step 4 comprises the following steps:

step 4.1, a construction rib (9) is arranged between every two adjacent fender posts (7) on the same side of the foundation pit, the construction rib (9) is of a net structure, and the construction rib (9) is fixedly connected with the fender posts (7);

and 4.2, erecting formworks on two sides of the construction ribs (9), pouring concrete in the formworks, and removing the formworks after the concrete reaches the designed strength.

4. A method of constructing a foundation pit enclosure for use within the reach of a pipeline according to claim 1 or 2, characterized in that: and 3, forming an included angle of 15 degrees between the retaining wall and the fender post in the vertical direction.

5. The method of claim 2 for the construction of a foundation pit enclosure within the influence of the pipeline, wherein: the thickness of the concrete sprayed on the reinforcing mesh (3) is 10 cm.

6. A method of constructing a foundation pit enclosure for use within the reach of a pipeline according to claim 1 or 3, wherein: the wall body of the enclosure wall (5) extends into the earthwork at the bottom layer of the foundation pit for less than 1 m.

7. A method of constructing a foundation pit enclosure for use within the reach of a pipeline according to claim 3, wherein: the structural rib (9) is fixedly connected with a reserved steel bar joint at the bottom of the crown beam (1).

8. A method of constructing a foundation pit enclosure for use within the reach of a pipeline according to claim 3, wherein: the two layers of the construction ribs (9) are arranged oppositely and are fixed on the fender post (7).