Construction methods for deep guide wall foundation pits of diaphragm walls

Abstract

This invention discloses a method for constructing a deep guide wall foundation pit for a diaphragm wall, comprising the following steps: Step 1, excavating a trench to the top surface of the top slab of the pipeline well; Step 2, vibrating and inserting positioning steel sheet piles; Step 3, vibrating and inserting retaining steel plates between the positioning steel sheet piles and the pipeline well; Step 4, pulling out the positioning steel sheet piles; Step 5, erecting a formwork in the trench to construct a guide wall, wherein the retaining steel plates extend into the guide wall and are welded to the reinforcing steel bars within the guide wall. This method for constructing a deep guide wall foundation pit for a diaphragm wall can significantly extend the depth of the guide wall, providing protection for adjacent pipeline wells, and avoiding excessive manual excavation, thus reducing the risk factor compared to existing technologies. Simultaneously, it eliminates the need to relocate adjacent pipeline wells, shortening the initial preparation period and reducing costs, and also minimizing problems during subsequent relocation.

Description

Technical Field

[0001] This invention relates to a method for constructing a deep guide wall foundation pit for underground continuous walls. Background Technology

[0002] With the accelerated development of underground space, large-scale pipelines that are difficult to relocate have become a significant factor restricting construction schedules. Currently, the relocation of most large-scale pipelines is lengthy, taking anywhere from three to four months to six months or even a year. Furthermore, post-relocation restoration presents a new challenge. The question remains: how to ensure the safety of pipelines while simultaneously enabling normal construction without relocating nearby ones?

[0003] To address the aforementioned problems, there is an urgent need for a construction method for deep guide wall foundation pits in diaphragm walls. Therefore, this invention presents a construction method for ultra-thin deep guide walls in diaphragm walls. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings of existing methods. This invention provides a method for constructing a deep guide wall foundation pit for underground continuous walls.

[0005] This invention is achieved through the following technical solution:

[0006] A method for constructing a deep guide wall foundation pit for a diaphragm wall includes the following steps:

[0007] Step 1: Excavate a trench down to the top surface of the pipeline well.

[0008] Step 2: Vibrate and insert the steel sheet piles for positioning;

[0009] Step 3: Vibrate and insert retaining steel plates between the positioning sheet piles and the pipeline well;

[0010] Step 4: Pull out the positioning steel sheet pile;

[0011] Step 5: Erect a formwork in the trench to construct a guide wall. The retaining steel plate extends into the guide wall and is welded to the reinforcing steel bars inside the guide wall.

[0012] Furthermore, each pair of the positioning sheet piles forms a group, with a spacing of 1200mm between two adjacent groups of positioning sheet piles, and a spacing of 600mm between any two positioning sheet piles in any group.

[0013] Furthermore, the bottom of the retaining steel plate has several channel steels.

[0014] Furthermore, the welding length between the top of the retaining steel plate and the reinforcing bars inside the guide wall is 250mm.

[0015] Furthermore, the top of the retaining steel plate has several holes.

[0016] Furthermore, the width of the retaining steel plate is 1000mm, the length of the retaining steel plate is 4500mm, and the thickness of the retaining steel plate is 4cm.

[0017] Furthermore, the positioning sheet pile is a Larssen sheet pile, the length of the positioning sheet pile is 5000mm, and the width of the positioning sheet pile is 400mm.

[0018] Furthermore, the two adjacent retaining steel plates overlap by 100mm.

[0019] The beneficial effects of this invention are as follows:

[0020] The underground continuous wall deep guide wall foundation pit construction method of the present invention can greatly extend the depth of the guide wall, protecting adjacent pipeline wells, and avoids excessive manual excavation, thus having a lower risk factor compared to existing technologies. At the same time, it eliminates the need to relocate adjacent pipeline wells, shortening the preliminary preparation period and reducing costs, and also minimizing problems during subsequent relocation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the internal structure of the underground continuous wall deep guide wall according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the internal structure of the underground continuous wall deep guide wall during the vibration insertion and positioning of steel sheet piles, according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of three sets of positioning steel sheet piles according to an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the internal structure of the underground continuous wall deep guide wall during the vibratory insertion of retaining steel plates, according to an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the structure of three sets of positioning sheet piles and retaining steel plates according to an embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of the retaining steel plate of the underground continuous wall deep guide wall according to an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] Trench 1

[0029] Pipeline Well 2

[0030] Positioning steel sheet piles 3

[0031] 4 retaining steel plates

[0032] 41 channel steel

[0033] Hole 42

[0034] Guide wall 5

[0035] Rebar 51 Detailed Implementation

[0036] The following description of the embodiments is taken with reference to the accompanying drawings, which illustrate specific embodiments in which the invention can be implemented.

[0037] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown in the figure, this embodiment discloses a method for constructing a deep guide wall foundation pit for a diaphragm wall. The method includes the following steps: Step 1, excavating the top surface of the top slab of the trench 1 to the pipeline well 2; Step 2, vibrating and inserting positioning steel sheet piles 3; Step 3, vibrating and inserting retaining steel plates 4 between the positioning steel sheet piles 3 and the pipeline well 2; Step 4, pulling out the positioning steel sheet piles 3; Step 5, erecting a formwork in the trench 1 to construct a guide wall 5, with the retaining steel plates 4 extending into the guide wall 5 and welded to the reinforcing bars 51 inside the guide wall 5.

[0038] By inserting retaining steel plates 4 next to the adjacent pipeline well 2, and connecting the retaining steel plates 4 to the guide wall 5 to form a whole, the depth of the guide wall 5 can be greatly extended by using the retaining steel plates 4 as part of the guide wall 5. This protects the adjacent pipeline well 2 without requiring excessive manual excavation, resulting in a lower risk factor compared to existing technologies. Furthermore, it eliminates the need to relocate the adjacent pipeline well 2, shortening the initial preparation period and reducing costs, while also minimizing problems during subsequent relocation.

[0039] like Figure 3 As shown, each pair of positioning sheet piles 3 forms a group, the distance between the two positioning sheet piles 3 in any group is 600mm, and the distance between two adjacent groups of positioning sheet piles 3 is 1200mm.

[0040] The positioning sheet pile 3 is a Larssen sheet pile, with a length of 5000mm and a width of 400mm. Preferably, the positioning sheet pile 3 is an SP-4W type Larssen sheet pile.

[0041] like Figure 5 As shown, the two adjacent retaining steel plates 4 overlap by 100mm and are arranged along the entire length of the pipeline.

[0042] The width of the retaining steel plate 4 is 1000mm, the length of the retaining steel plate 4 is 4500mm, and the thickness of the retaining steel plate 4 is 4cm.

[0043] like Figure 6As shown, the bottom of the retaining steel plate 4 has several channel steels 41. In this embodiment, two channel steels 41 are provided at the bottom of the retaining steel plate 4. The length of the channel steels 41 is 4000mm, which effectively strengthens the overall rigidity of the retaining steel plate 4.

[0044] The weld length between the top of the retaining steel plate 4 and the reinforcing bar 51 inside the guide wall 5 is 250mm. The top of the retaining steel plate 4 has several holes 42. In this embodiment, there are two holes 42, and the size of the two holes 42 is 150mm*150mm, which facilitates the vibration insertion of the vibratory insertion equipment.

[0045] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for constructing a deep guide wall foundation pit for a diaphragm wall, characterized in that, It includes the following steps: Step 1: Excavate a trench down to the top surface of the pipeline well. Step 2: Vibrate and insert the steel sheet piles for positioning; Step 3: Vibrate and insert retaining steel plates between the positioning sheet piles and the pipeline well; Step 4: Pull out the positioning steel sheet pile; Step 5: Erect a formwork in the trench to construct a guide wall. The retaining steel plate extends into the guide wall and is welded to the reinforcing steel bars inside the guide wall.

2. The method for constructing a deep guide wall foundation pit for a diaphragm wall as described in claim 1, characterized in that, Each pair of the positioning sheet piles forms a group, with a spacing of 1200mm between two adjacent groups of positioning sheet piles, and a spacing of 600mm between any two positioning sheet piles in any group.

3. The method for constructing a deep guide wall foundation pit for a diaphragm wall as described in claim 1, characterized in that, The bottom of the retaining steel plate has several channel steels.

4. The method for constructing a deep guide wall foundation pit for a diaphragm wall as described in claim 1, characterized in that, The weld length between the top of the retaining steel plate and the reinforcing steel bar inside the guide wall is 250mm.

5. The method for constructing a deep guide wall foundation pit for a diaphragm wall as described in claim 1, characterized in that, The top of the retaining steel plate has several holes.

6. The method for constructing a deep guide wall foundation pit for a diaphragm wall as described in claim 1, characterized in that, The retaining steel plate has a width of 1000mm, a length of 4500mm, and a thickness of 4cm.

7. The method for constructing a deep guide wall foundation pit for a diaphragm wall as described in claim 1, characterized in that, The positioning sheet pile is a Larssen sheet pile, the length of which is 5000mm and the width of which is 400mm.

8. The method for constructing a deep guide wall foundation pit for a diaphragm wall as described in claim 1, characterized in that, The overlap between two adjacent retaining steel plates is 100mm.

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