Underground diaphragm wall profile steel joint breaking and removing method

Abstract

The invention belongs to the technical field of underground diaphragm wall construction, and relates to an underground diaphragm wall profile steel joint breaking method which comprises the following steps: reinforcing a soil body on the outer side of the position of an underground diaphragm wall profile steel joint to form a complete reinforcing body; a hole is mechanically formed in the position of a profile steel connector close to the diaphragm wall, a steel casing is placed, grouting and bottom sealing are conducted on the bottom of the steel casing, and slurry in the steel casing is removed; building a construction platform in the steel casing, and grouting to reinforce a soil body on the back of the diaphragm wall; the steel casing in the range of the section steel joints needing to be broken is cut off in a segmented mode from bottom to top, the section steel joints are broken, the broken range is backfilled with plain concrete, notches of the steel casing are welded and closed after backfilling, and after one section of construction is completed, an operation platform is erected for next section of construction till chiseling construction is completed; hoisting out the working platform and equipment in the steel sleeve, and pulling out the steel casing; and the shield penetrates through the diaphragm wall for construction. The method solves the problems of high risk, large investment, long construction period and the like caused by the adoption of a traditional technology for the underground diaphragm wall type steel joint encountered by the shield.

Description

Technical Field

[0001] The invention belongs to the technical field of ground-connected wall construction, relates to a method for breaking ground-connected wall steel joints, and in particular to a construction method for breaking ground-connected wall steel joints before a shield machine passes through a ground-connected wall without reserved conditions. Background Art

[0002] When constructing underground structures by open-cut method, ground-connected walls are often used as enclosure structures. If the long-term shield tunneling conditions are considered in the planning stage, the ground-connected walls will adopt forms such as sleeve milling joints and lock-mouth pipe joints to facilitate direct cutting through by the shield machine.

[0003] Due to planning adjustments and other reasons, shield tunnels often need to pass through structures without reserved ground-connected walls. It is common for shields to directly cut retaining piles and ground-connected walls, but there is no precedent for directly cutting steel joints, which makes construction difficult and risky.

[0004] At present, the commonly used treatment method is to dig a tunnel or dig a shaft close to the existing ground-connected wall, and manually remove the steel structure within the shield crossing range. Traditional demolition technology has high construction risks, long construction period, high project cost, and is very likely to affect the existing structure and have a great impact on the environment. Especially for saturated soft soil layers, traditional methods are even more difficult to apply.

[0005] In view of the above situation, a new method for breaking the ground-anchored wall steel joints is proposed, which has great practical significance. Summary of the invention

[0006] In view of the many shortcomings of traditional tunnel or shaft demolition solutions, the present invention proposes a method for demolishing ground-anchored wall steel joints with low construction risk, short cycle and low cost.

[0007] The technical solution of the present invention is: a method for breaking a ground-connected wall steel joint, comprising the following steps: S1: Reinforce the soil outside the ground-connected wall steel joint to form a complete reinforcement body; S2: Mechanically drill holes at the steel joint location close to the ground wall and install steel casings. Grout the bottom of the steel casings and remove the mud inside the steel casings. S3: Set up an operating platform inside the steel casing and inject grout to reinforce the soil on the back of the ground-connected wall; S4: Cut off the steel casing in sections from bottom to top in the range of the steel joints to be broken, break the steel joints, backfill the broken range with plain concrete, weld and seal the gap of the steel casing after backfilling, and raise the operating platform to carry out the next section of construction after completing one section, until the steel joints in the range of shield crossing are completely chiseled out; S5: Lift out the operating platform and equipment inside the steel sleeve and remove the steel casing; S6: Construction of shield tunneling through ground-anchored wall.

[0008] Preferably, the soil reinforcement method outside the structure of the medium-sized steel joint position in step S1 is selected according to the stratum conditions, and high-pressure rotary spraying, mixing piles, sleeve valve pipe grouting, drilling and injection machine grouting reinforcement, etc. can be used.

[0009] Further preferably, the range of the reinforcement body in step S1, the bottom sealing thickness in step S2 and the range of the back grouting reinforcement of the wall in step S3 are determined according to the stratum and water pressure.

[0010] Further preferably, in step S2, the diameter of the steel casing is about 2 m, which can also be adjusted according to construction needs.

[0011] Further preferably, the grouting reinforcement of the soil on the back of the ground-connected wall in step S3 can be carried out by grouting with a grouting pipe or grouting with a drilling and grouting machine according to the construction conditions. The grouting holes are arranged along both sides of the steel joint. When grouting is carried out with a grouting pipe, the grouting pipe should be pulled out after the grouting is completed.

[0012] Further preferably, when the bottom of the ground-anchored wall steel joint in step S3 is located within the shield tunneling range, grouting reinforcement is also required for the bottom range of the ground-anchored wall.

[0013] Further preferably, in step S4, before the steel casing is removed, it should be determined by calculation based on the formation and water pressure conditions whether to set a temporary internal support in the steel casing.

[0014] Further preferably, in step S4, the segment length of the steel sleeve removal, ground-anchored wall steel removal, plain concrete backfilling, and steel casing welding and sealing operations generally does not exceed 1 m.

[0015] Further preferably, in step S5, the steel sleeve should be removed while backfilling to prevent hole collapse.

[0016] The present invention has the following obvious beneficial effects: 1. The present invention adopts a steel casing support system through simple construction steps, and removes the steel joints in the shield crossing range in sections, thus solving many problems of traditional technology such as high risk, large investment, and long construction period.

[0017] 2. The present invention adopts steel casing support. Compared with the traditional open-cut shaft, the construction method is simple, the construction period is short, and the impact on the surrounding environment is small.

[0018] 3. The present invention has small requirements for the construction site, and the difficulty and cost of pipeline relocation and traffic diversion are relatively low.

[0019] 4. The project cost of the present invention is low, the steel casing can be recycled and reused, and less waste is generated.

[0020] In addition, the following important aspects are also provided as auxiliary evidence of the inventiveness of the present invention: 1. The technical solution of the present invention fills the technical gap in the industry at home and abroad: the traditional method adopts open-cut vertical shaft construction, and the present invention creatively applies steel-cased concrete support and removes the I-beam joints in sections.

[0021] 2. Whether the technical solution of the present invention solves the technical problems that people have been eager to solve but have never succeeded in solving: The present invention solves the problems that the traditional method occupies a large area, is difficult to relocate pipelines and traffic diversion, and is expensive. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0023] Figure 1 This is a plan view of step S1 of the present invention; Figure 2 This is a plan view of step S2 of the present invention; Figure 3 This is a plan view of step S3 of the present invention; Figure 4 This is a schematic plan view of the steel sleeve removal and ground-connected wall steel removal in step S4 of the present invention; Figure 5 This is a schematic diagram of the grouting backfilling and steel casing welding closure in step S4 of the present invention; Figure 6 It is a cross-sectional schematic diagram of Embodiment 1 of the present invention; Figure 7 It is a cross-sectional schematic diagram of a second embodiment of the present invention; Figure 8 This is a cross-sectional view of step S1 of embodiment 1 of the present invention; Fig. 9 This is a cross-sectional view of step S2 of embodiment 1 of the present invention; Fig.10 This is a cross-sectional view of step S3 of embodiment 1 of the present invention; Fig.11 This is a construction cross-sectional view of the first section of steel sleeve removal and ground-connected wall steel removal in step S4 of the first embodiment of the present invention; Fig.12 This is a cross-sectional view of the construction of the first section of plain concrete backfilling and steel casing welding closure in step S4 of the first embodiment of the present invention; Fig.13 This is a cross-sectional view of the second stage of construction of step S4 in the first embodiment of the present invention; Fig.14 This is a cross-sectional view after the construction of step S4 of the first embodiment of the present invention is completed; Fig.15 This is a schematic diagram of the shield tunneling after the steel sleeve is removed in step S5 of the first embodiment of the present invention. DETAILED DESCRIPTION

[0024] First of all, it should be noted that the specific structure, features and advantages of the present invention will be specifically described below by way of example, but all descriptions are only for illustration and should not be understood as limiting the present invention in any way. In addition, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature displayed or implied in the drawings, can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned in this document. In addition, in order to simplify the drawings, the same or similar technical features may be marked only in one place in the same drawing.

[0025] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The present invention is described in detail below with reference to the accompanying drawings. Embodiment 1

[0027] like Figure 1 to Figure 6 , Figure 8~Figure 15 A method for breaking a ground-connected wall steel joint comprises the following steps: S1: Use jet grouting piles to reinforce the soil outside the ground-connected wall steel joint to form a complete reinforcement body. The scope of the reinforcement body is determined according to the stratum and water pressure; S2: Mechanically drill holes at the steel joint location close to the ground wall and install steel casing. The diameter of the steel casing is 2m. Grouting is performed at the bottom of the steel casing, and then the mud in the steel casing is removed; S3: Set up an operating platform inside the steel casing, and grouting is performed to reinforce the soil on the back of the ground-connected wall. Grouting of the soil on the back of the ground-connected wall is performed by grouting with a grouting pipe or a drilling and grouting machine according to the construction conditions. The grouting holes are arranged along both sides of the steel joints. When grouting is performed with a grouting pipe, the grouting pipe should be removed after the grouting is completed. When the bottom of the ground-connected wall steel joint is within the shield crossing range, the bottom of the ground-connected wall needs to be grouted for reinforcement. Taking this embodiment as an example, a grouting pipe is used to reinforce the soil on the back of the ground-connected wall. The grouting holes are arranged along both sides of the steel joints. The grouting pipe should be removed after the grouting is completed. S4: Supplementary grouting is performed on the soil between the steel casing and the ground-connected wall, and the I-beam joints are chiseled out in sections of 1m from bottom to top. The construction process is as follows: temporary internal support is set up in the steel casing, the steel casing in the range of the steel joints to be removed is removed, the steel joints are removed, and the removed range is backfilled with plain concrete. After backfilling, the gap in the steel casing is welded and sealed. After completing one section, an elevated operating platform is erected to carry out the next section until the chiseling construction is completed; S5: Lift out the internal operating platform and equipment of the steel casing, and remove the steel casing by grouting and removing at the same time; S6: Construction of shield tunneling through ground-anchored wall.

[0028] The method for removing the ground-anchored wall steel joints in this embodiment adopts a steel casing support system to remove the steel joints in sections within the shield crossing range. Compared with the traditional open-cut vertical shaft, the construction method is simple, the construction period is short, the project cost is low, the construction risk is small, and the impact on the surrounding environment is small. Embodiment 2

[0029] like Figure 1 to Figure 7 A method for breaking a ground-connected wall steel joint comprises the following steps: S1: Use sleeve valve pipe grouting to reinforce the soil outside the joint of the ground-connected wall steel to form a complete reinforcement body. The scope of the reinforcement body is determined according to the stratum and water pressure; S2: Mechanically drill holes at the steel joint location close to the ground wall and install steel casing. The diameter of the steel casing is 2m. Grouting is performed at the bottom of the steel casing, and then the mud in the steel casing is removed; S3: Set up an operating platform inside the steel casing, and grouting is performed to reinforce the soil on the back of the ground-connected wall. Grouting of the soil on the back of the ground-connected wall is performed by grouting with a grouting pipe or a drilling and grouting machine according to the construction conditions. The grouting holes are arranged along both sides of the steel joints. When grouting is performed with a grouting pipe, the grouting pipe should be removed after the grouting is completed. When the bottom of the ground-connected wall steel joint is within the shield crossing range, the bottom of the ground-connected wall needs to be grouted for reinforcement. Taking this embodiment as an example, a grouting pipe is used to reinforce the soil on the back of the ground-connected wall. The grouting holes are arranged along both sides of the steel joints. The grouting pipe should be removed after the grouting is completed. S4: Supplementary grouting is carried out for the soil between the steel casing and the ground-connected wall, and the I-beam joints are chiseled out in sections of 1m from bottom to top. The construction process is as follows: after cutting out the steel casing in the range of the steel joints to be removed, the steel joints are removed, and the removed range is backfilled with plain concrete. After backfilling, the gap of the steel casing is welded and sealed. After completing one section, an operating platform is raised to carry out the next section until the chiseling construction is completed; S5: Lift out the internal operating platform and equipment of the steel casing, and remove the steel casing by grouting and removing at the same time; S6: Construction of shield tunneling through ground-anchored wall.

[0030] The method for removing the ground-anchored wall steel joints in this embodiment adopts a steel casing support system to remove the steel joints in sections within the shield crossing range. Compared with the traditional open-cut vertical shaft, the construction method is simple, the construction period is short, the project cost is low, the construction risk is small, and the impact on the surrounding environment is small.

[0031] The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for breaking a ground-connected wall steel joint, characterized in that: The following steps are involved: S1: Reinforce the soil outside the ground-connected wall steel joint to form a complete reinforcement body; S2: Mechanically drill holes at the steel joint location close to the ground wall and install steel casings. Grout the bottom of the steel casings and remove the mud inside the steel casings. S3: Set up an operating platform inside the steel casing and inject grout to reinforce the soil on the back of the ground-connected wall; S4: Cut off the steel casing in sections from bottom to top in the range of the steel joints to be broken, break the steel joints, backfill the broken range with plain concrete, weld and seal the gap of the steel casing after backfilling, and after completing one section, raise the operating platform to carry out the next section construction until the chiseling construction is completed; S5: Lift out the operating platform and equipment inside the steel sleeve and remove the steel casing; S6: Construction of shield tunneling through ground-anchored wall.

2. A method for breaking a ground-connected wall steel joint according to claim 1, characterized in that: In step S1, the soil reinforcement method outside the ground-connected wall steel joint position is selected according to the stratum conditions, and one or more of high-pressure rotary grouting, mixing piles, sleeve valve pipe grouting, and drilling and grouting machine grouting reinforcement are adopted.

3. A method for breaking a ground-connected wall steel joint according to claim 1, characterized in that: The range of the reinforcement body in step S1, the thickness of the bottom cover in step S2, and the range of the grouting reinforcement on the back of the ground-connected wall in step S3 are determined according to the stratum and water pressure.

4. A method for breaking a ground-connected wall steel joint according to claim 1, characterized in that: In step S2, the diameter of the steel casing is 2m and is adjusted according to construction needs.

5. A method for breaking a ground-connected wall steel joint according to claim 1, characterized in that: In step S3, the soil grouting reinforcement on the back of the ground-connected wall is carried out by grouting with a grouting pipe or grouting with a drilling and grouting machine according to the construction conditions. The grouting holes are arranged along both sides of the steel joint. When grouting with a grouting pipe is used, the grouting pipe should be pulled out after the grouting is completed.

6. A method for breaking a ground-connected wall steel joint according to claim 1, characterized in that: In step S3, when the bottom of the ground-anchored wall steel joint is located within the shield tunneling range, grouting reinforcement is required for the bottom of the ground-anchored wall.

7. A method for removing a ground-connected wall steel joint according to claim 1, characterized in that: In step S4, before the steel casing is removed, it is determined whether to set a temporary internal support in the steel casing according to the formation and water pressure conditions.

8. A method for breaking a ground-connected wall steel joint according to claim 1, characterized in that: In step S4, the segment length of the steel sleeve removal, ground-connected wall steel removal, plain concrete backfilling, and steel casing welding and sealing operations shall not exceed 1m.

9. A method for removing a ground-connected wall steel joint according to claim 1, characterized in that: In step S5, the steel sleeve is removed while backfilling to prevent hole collapse.

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