Method for dismantling front support grouting steel pipe in advance

Abstract

The invention belongs to the technical field of foundation pit engineering, and particularly relates to a method for dismantling front support grouting steel pipes in advance, which comprises two ring beams arranged upwards along the bottom edge line of a foundation pit, a plurality of connecting beams arranged in the foundation pit and positioned between the two ring beams, and a plurality of front support grouting steel pipes arranged on the bottom side of the ring beam at the lowest position and positioned in the foundation pit. The dismantling method comprises the following steps that a plurality of dismantled front support grouting steel pipes are fixed, fender posts are hit on soil around the fixed front support grouting steel pipes for protection treatment, and then the interiors of the fender posts are cleaned; the foundation pit is excavated to the bottom of the foundation pit, the foundation pit is cleaned, and a bottom plate of a construction structure is added, so that after the bottom plate is completed, pre-dismantling of part of front support grouting steel pipes and redistribution feedback of water and soil side pressure acting on the steel pipes are more visual and rapid after part of the front support grouting steel pipes are dismantled; the stress condition of the adjacent steel pipes after dismantling can be better known, the risk can be predicted in advance, and the safety of the foundation pit is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of foundation pit engineering, and in particular relates to a method for early removal of a front support grouting steel pipe. Background Art

[0002] The second-floor basement foundation pit adopts double-row piles + front support grouting steel pipe enclosure, which has been widely used in foundation pit projects. The front support grouting steel pipe generally needs to be removed after the middle floor slab and the middle floor slab are replaced; however, some front support grouting steel pipes conflict with the main structure such as structural columns and structural walls, and need to be removed in advance after the bottom slab and the bottom slab are replaced. At present, the project generally guides the removal by monitoring the deformation of the front support grouting steel pipe area to be removed before and after the removal, which is not direct and intuitive, and the feedback is relatively slow.

[0003] When some front support grouting steel pipes need to be removed in advance after the base plate and base plate support replacement are completed, the current projects generally use the area of ​​the front support grouting steel pipes to be removed and the adjacent deformation monitoring to guide the removal, which is not direct and intuitive enough and the feedback is relatively slow.

[0004] On this basis, an intuitive and fast method to guide the early removal of part of the front support grouting steel pipes after the base plate is completed is proposed. In view of this, we propose a method for early removal of the front support grouting steel pipes. Summary of the invention

[0005] The purpose of the present invention is to provide a method for early removal of front support grouting steel pipes to solve the problems raised in the above background technology.

[0006] In view of this, the present invention provides a method for early removal of front support grouting steel pipes, comprising two ring beams extending upward along the bottom edge of a foundation pit, a plurality of connecting beams arranged in the foundation pit between the two ring beams, and a plurality of front support grouting steel pipes arranged on the bottom side of the lowest ring beam in the foundation pit. The removal method comprises the following steps: Fix the removed front support grouting steel pipes, drive retaining piles into the soil around the fixed front support grouting steel pipes for protection, and then clean the inside of the retaining piles; Excavate the foundation pit to the bottom and clean it, add the bottom plate of the construction structure, and remove the C1, C2...C7 front support grouting steel pipes in advance according to the conflicts with the structural columns and structural walls; The demolition method mainly based on mechanical demolition is adopted to carry out the demolition step by step from top to bottom; Axial force gauges are placed on both sides of the steel pipes supporting the grouting steel pipe to be removed in advance; then they are removed one by one in the order of C1→C2…C6→C7. After one pipe is removed, the axial force on both sides and the adjacent deformation monitoring results are checked to see if there are no abnormalities, and then the next steel pipe can be cut off; the two adjacent areas need to be removed in advance, and after the removal of this area is completed, the remaining adjacent one C7 can be removed based on the monitoring results.

[0007] In this technical solution, before demolition, there are areas where multiple steel pipes need to be demolished in advance. First, make preparations before construction, survey the site ring, and bring enough tools. Then, the construction workers will build retaining piles on the construction site to prevent non-staff from entering the construction site. The soil around the removed front support grouting steel pipes will be protected with retaining piles, and then the garbage inside the retaining piles will be cleaned; Afterwards, the personnel excavated the foundation pit to the bottom of the pit and cleaned it, and also added a bottom plate of the construction structure at the bottom of the pit to facilitate the movement of the construction personnel and prevent them from falling or being tripped by other objects. Afterwards, the construction personnel can take the tools such as handles, pliers and screwdrivers prepared before construction to first remove the bolts, nuts and screws on the two ring beams and several connecting beams, and then use the demolition method mainly based on mechanical demolition to gradually demolish them in a top-down order, remove the steel pipes on both sides of the front support grouting steel pipe in advance, and lay out the axial force gauges, and finally remove them one by one in the order of C1→C2...C6→C7. After removing one, look at the axial force on both sides and the adjacent deformation monitoring results. If there is no abnormality, continue to cut the next steel pipe; it is necessary to remove the two adjacent areas in advance, and after the jump demolition of this area is completed, go back and remove the remaining adjacent one C7 according to the monitoring results; When the area of ​​two adjacent front-support grouting steel pipes needs to be removed locally, axial force gauges are arranged on the steel pipes on both sides of the front-support grouting steel pipes to be removed in advance. First, one C1 is cut off. When there are no abnormalities in the axial forces and adjacent deformation monitoring on both sides, the second C2 is cut off.

[0008] In the above technical solution, further, a plurality of protective support frames are arranged at intervals on the bottom plate of the construction structure.

[0009] In this technical solution, when construction workers are performing dismantling at the bottom of the pit, they can stand on several protective support frames, which can protect the workers and increase the height at which they stand, making it easier to dismantle the two ring beams and several connecting beams.

[0010] In the above technical solution, further, before dismantling the front support grouting steel pipe, the front support grouting steel pipe should be struck multiple times with a hammer to break the cement slurry shell solidified on the surface of the front support grouting steel pipe.

[0011] In this technical solution, it is ensured that the front-support grouting steel pipe can be partially and gradually dismantled. By using a hammer to hit the front-support grouting steel pipe multiple times, the solidified cement slurry shell on the surface of the front-support grouting steel pipe can be shaken off, so as to reduce damage to the cutting machinery in the subsequent mechanical cutting process.

[0012] In the above technical solution, further, the cement slurry shell falling from the surface of the front support grouting steel pipe is collected by a broom, a shovel and a trash can and put into the trash can.

[0013] In this technical solution, after the construction workers knock the cement slurry shell on the surface of the front support grouting steel pipe to the bottom of the pit, the construction workers use a broom to sweep a large amount of cement shell onto the shovel. Then, the workers pour the cement shell on the shovel into the trash can for collection, ensuring that the cement shell at the bottom of the pit is cleaned up, which is convenient for the construction workers to move around and prevents people from tripping.

[0014] In the above technical solution, further, the mechanical demolition uses a cutting machine to cut off the two ring beams and the plurality of connecting beams and stack them together.

[0015] In this technical solution, before removing the front support grouting steel pipe, the construction workers first use a cutting machine to separate the two ring beams and several connecting beams. Then, they organize and stack the disassembled ring beams and connecting beams together to facilitate subsequent transportation out of the pit.

[0016] In the above technical solution, further, after the ring beam and the plurality of connecting beams are cut, the plurality of front support grouting steel pipes are cut in sections.

[0017] In this technical solution, the front support grouting steel pipe in the foundation pit can be partially, phased and segmentedly removed, and the front support grouting steel pipe can be cut into segments by a cutting machine.

[0018] In the above technical scheme, further, after the two ring beams, several connecting beams and several front support grouting steel pipes are dismantled and arranged neatly, the two ring beams, several connecting beams and several front support grouting steel pipes are tied up with hemp ropes.

[0019] In this technical solution, the construction workers divide the ring beam, connecting beam and front support grouting steel pipe into three batches and use hemp rope to bundle and fix the ring beam, connecting beam and front support grouting steel pipe, so that subsequent construction workers can transport the bundled and fixed ring beam, connecting beam and front support grouting steel pipe out of the foundation pit.

[0020] In the above technical solution, further, the two ring beams, several connecting beams and several front support grouting steel pipes after being removed by the hemp rope are lifted up and out of the foundation pit by the crane. In this technical solution, construction workers operate a crane, fix the rope on the crane to the bound and fixed ring beam, connecting beam and front support grouting steel pipe, and then operate the crane to transport the ring beam, connecting beam and front support grouting steel pipe out of the foundation pit.

[0021] The beneficial effects of the present invention are: 1. The method for early removal of the front support grouting steel pipe can intuitively guide the early removal of part of the front support grouting steel pipe after the base plate is completed.

[0022] 2. The method of early removal of the front support grouting steel pipe, after some of the front support grouting steel pipes are removed, the redistribution feedback of the water and soil side pressure acting on the steel pipe is more intuitive and rapid, which can better understand the stress conditions of the adjacent steel pipes after removal, predict risks in advance, and ensure the safety of the foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a construction process flow chart of the present invention; Figure 2 One of the schematic diagrams of the method for early removal of the front support grouting steel pipe of the present invention; Figure 3 Schematic diagram 2 of the method for early removal of the front support grouting steel pipe of the present invention; Figure 4 Schematic diagram of the method for early removal of the front support grouting steel pipe of the present invention (3); Figure 5 Schematic diagram 4 of the invented method for early removal of the front support grouting steel pipe; Figure 6 Schematic diagram of the invented method for early removal of the front support grouting steel pipe No. 5; Figure 7 Schematic diagram six of the method for early removal of the front support grouting steel pipe of the present invention.

[0024] The symbols in the figure are: 1. Front support grouting steel pipe; 2. Ring beam; 3. Connecting beam; 4. Foundation pit bottom edge; 5. Axial force gauge. DETAILED DESCRIPTION

[0025] The following is combined with Figure 1-Figure 6 This application is described in further detail.

[0026] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0027] Embodiment 1: This embodiment provides a method for early removal of front support grouting steel pipes, comprising two ring beams 2 extending upward along the bottom edge 4 of the foundation pit, a plurality of connecting beams 3 arranged in the foundation pit between the two ring beams 2, and a plurality of front support grouting steel pipes 1 arranged on the bottom side of the lowest ring beam 2 in the foundation pit. The removal method comprises the following steps: The removed several front support grouting steel pipes 1 are fixed, and the soil around the fixed several front support grouting steel pipes 1 is protected by retaining piles, and then the inside of the retaining piles is cleaned; Excavate the foundation pit to the bottom and clean it, add the bottom plate of the construction structure, and remove the C1, C2...C7 front support grouting steel pipes in advance according to the conflicts with the structural columns and structural walls; The demolition method mainly based on mechanical demolition is adopted to carry out the demolition step by step from top to bottom; Arrange axial force gauges 5 on both sides of the steel pipes before the early removal of the support grouting steel pipe; then remove them one by one in the order of C1→C2…C6→C7. After removing one steel pipe, check the monitoring results of the axial forces on both sides and the adjacent deformations, and if there is no abnormality, continue to cut off the next steel pipe; it is necessary to remove the two adjacent areas in advance, and after the removal of this area is completed, go back and remove the remaining adjacent one C7 according to the monitoring results.

[0028] Among them, before demolition, there are multiple steel pipes that need to be demolished in advance. First, make preparations before construction, survey the site ring, and bring enough tools. Then, the construction personnel will build retaining piles on the construction site to prevent non-staff from entering the construction site. The soil around the removed front support grouting steel pipes 1 will be protected with retaining piles, and then the garbage inside the retaining piles will be cleaned; Afterwards, the personnel excavate the foundation pit to the bottom of the pit and clean it, and also add a bottom plate of the construction structure at the bottom of the pit to facilitate the movement of the construction personnel and prevent them from falling or being tripped by other objects. Afterwards, the construction personnel can take the tools such as handles, pliers and screwdrivers prepared before construction to first remove the bolts, nuts and screws on the two ring beams 2 and several connecting beams 3, and then use the demolition method mainly based on mechanical demolition to gradually demolish them in a top-to-bottom order, remove the steel pipes on both sides of the front support grouting steel pipe in advance, and lay out the axial force gauges 5, and finally remove them one by one in the order of C1→C2...C6→C7. After removing one, according to the monitoring results of the axial forces on both sides and the adjacent deformation, if there is no abnormality, continue to cut off the next steel pipe; it is necessary to remove the adjacent two areas in advance, and after the jump demolition of this area is completed, go back and remove the remaining adjacent one C7 according to the monitoring results; When two adjacent front support grouting steel pipes 1 need to be partially removed, axial force gauges 5 are arranged on the steel pipes on both sides of the front support grouting steel pipes to be removed in advance, and one C1 is cut off first. When there is no abnormality in the axial force and adjacent deformation monitoring on both sides, the second C2 is cut off.

[0029] Embodiment 2: This embodiment provides a method for early removal of front-support grouting steel pipes. In addition to the technical solutions of the above embodiments, it also has the following technical features: a plurality of protective support frames are arranged at intervals on the bottom plate of the construction structure.

[0030] When construction workers are dismantling at the bottom of the pit, they can stand on several protective support frames, which can protect the workers and increase the height at which the workers stand, making it easier to dismantle the two ring beams 2 and several connecting beams 3.

[0031] Example 3: This example provides a method for early removal of a front-support grouting steel pipe. In addition to the technical solutions of the above examples, it also has the following technical features: before removing the front-support grouting steel pipe 1, a hammer should be used to hit the front-support grouting steel pipe 1 multiple times to break the cement slurry shell solidified on the surface of the front-support grouting steel pipe 1.

[0032] Among them, it is ensured that the front-support grouting steel pipe 1 can be partially, partially and segmentally dismantled. The front-support grouting steel pipe 1 is hit multiple times with a hammer, which can shake off the solidified cement slurry shell on the surface of the front-support grouting steel pipe 1, so as to reduce damage to the cutting machine in the subsequent mechanical cutting process.

[0033] Example 4: This example provides a method for early removal of a front-support grouting steel pipe. In addition to the technical solutions of the above examples, it also has the following technical features: the cement slurry shell falling from the surface of the front-support grouting steel pipe 1 is collected by a broom, a shovel and a trash can and put into a trash can.

[0034] Among them, when the construction workers knock the cement slurry shell on the surface of the front support grouting steel pipe 1 to the bottom of the pit, the construction workers use a broom to sweep a large amount of cement shells onto the shovel. Then, the workers pour the cement shells on the shovel into the trash can for collection, ensuring that the cement shells at the bottom of the pit are cleaned up, which is convenient for the construction workers to move around and prevent people from tripping.

[0035] Embodiment 5: This embodiment provides a method for early removal of front support grouting steel pipes. In addition to the technical solutions of the above embodiments, it also has the following technical features: mechanical removal uses a cutting machine to cut off two ring beams 2 and several connecting beams 3 and stack them together.

[0036] Among them, before dismantling the front support grouting steel pipe 1, the construction workers first use a cutting machine to separate the two ring beams 2 and several connecting beams 3, and then arrange the disassembled ring beams 2 and connecting beams 3 neatly and stack them together for subsequent transportation out of the pit.

[0037] Example 6: This example provides a method for early removal of front-support grouting steel pipes. In addition to the technical solutions of the above examples, it also has the following technical features: after the ring beam 2 and several connecting beams 3 are cut, several front-support grouting steel pipes 1 are cut in sections.

[0038] The front support grouting steel pipe 1 in the foundation pit can be partially, phased and segmentedly removed, and the front support grouting steel pipe 1 can be cut into segments by a cutting machine.

[0039] Example 7: This example provides a method for early removal of front-support grouting steel pipes. In addition to the technical solutions of the above examples, it also has the following technical features: after the two ring beams 2, the connecting beams 3 and the front-support grouting steel pipes 1 are removed, the two ring beams 2, the connecting beams 3 and the front-support grouting steel pipes 1 are neatly arranged, and then the two ring beams 2, the connecting beams 3 and the front-support grouting steel pipes 1 are bundled with hemp ropes.

[0040] Among them, the construction workers divided the ring beam 2, the connecting beam 3 and the front support grouting steel pipe 1 into three batches and used hemp rope to bundle and fix the ring beam 2, the connecting beam 3 and the front support grouting steel pipe 1, so that subsequent construction workers can transport the bundled and fixed ring beam 2, the connecting beam 3 and the front support grouting steel pipe 1 out of the foundation pit.

[0041] Example 8: This example provides a method for early removal of front-support grouting steel pipes. In addition to the technical solutions of the above examples, it also has the following technical features: the two ring beams 2, several connecting beams 3 and several front-support grouting steel pipes 1 that are tied with hemp ropes are removed by a crane and lifted out of the foundation pit.

[0042] Among them, the construction workers operate the crane, fix the rope on the crane to the bound and fixed ring beam 2, connecting beam 3 and front support grouting steel pipe 1, and then let the crane run to transport the ring beam 2, connecting beam 3 and front support grouting steel pipe 1 out of the foundation pit.

[0043] Working principle: Before demolition, there are multiple front support grouting steel pipes 1 that need to be demolished in advance. First, make preparations before construction, survey the site ring, and bring enough tools. Then, the construction personnel will build retaining piles on the construction site to prevent non-staff from entering the construction site. The soil around the removed front support grouting steel pipes 1 will be protected with retaining piles, and then the garbage inside the retaining piles will be cleaned; Afterwards, the personnel excavate the foundation pit to the bottom of the pit and clean it, and also add a bottom plate of the construction structure at the bottom of the pit to facilitate the movement of the construction personnel and prevent them from falling or being tripped by other objects. Afterwards, the construction personnel can take the tools such as handles, pliers and screwdrivers prepared before construction to first remove the bolts, nuts and screws on the two ring beams 2 and several connecting beams 3, and then use the demolition method mainly based on mechanical demolition to gradually demolish them in a top-to-bottom order, remove the steel pipes on both sides of the front support grouting steel pipe in advance, and lay out the axial force gauges 5, and finally remove them one by one in the order of C1→C2...C6→C7. After removing one, according to the monitoring results of the axial forces on both sides and the adjacent deformation, if there is no abnormality, continue to cut off the next steel pipe; it is necessary to remove the adjacent two areas in advance, and after the jump demolition of this area is completed, go back and remove the remaining adjacent one C7 according to the monitoring results; When two adjacent front support grouting steel pipes 1 need to be partially removed, axial force gauges 5 are arranged on the steel pipes on both sides of the front support grouting steel pipes to be removed in advance, and one C1 is cut off first. When there is no abnormality in the axial force and adjacent deformation monitoring on both sides, the second C2 is cut off.

[0044] The embodiments of the present application are described above in conjunction with the accompanying drawings. In the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A method for early removal of front support grouting steel pipes, comprising two ring beams (2) extending upward along the bottom edge (4) of a foundation pit, a plurality of connecting beams (3) arranged in the foundation pit and located between the two ring beams (2), a plurality of front support grouting steel pipes (1) arranged on the bottom side of the lowest ring beam (2) and located in the foundation pit, characterized in that: The removal method includes the following steps: The removed plurality of front support grouting steel pipes (1) are fixed, and the soil around the fixed plurality of front support grouting steel pipes (1) is protected by retaining piles, and then the inside of the retaining piles is cleaned; Excavate the foundation pit to the bottom and clean it, add the bottom plate of the construction structure, and remove the C1, C2...C7 front support grouting steel pipes in advance according to the conflicts with the structural columns and structural walls; The demolition method mainly based on mechanical demolition is adopted to carry out the demolition step by step from top to bottom; Axial force gauges (5) are arranged on both sides of the steel pipes before the grouting steel pipes are removed in advance. Then, they are removed one by one in the order of C1 → C2…C6 → C7. After one steel pipe is removed, the axial forces on both sides and the adjacent deformation monitoring results are checked to see if there are no abnormalities. Then, the next steel pipe can be cut off. It is necessary to remove two adjacent areas in advance. After the removal of these areas is completed, the remaining adjacent one C7 can be removed according to the monitoring results.

2. A method for early removal of front support grouting steel pipe according to claim 1, characterized in that: A plurality of protective support frames are arranged at intervals on the bottom plate of the construction structure.

3. A method for early removal of front support grouting steel pipe according to claim 1, characterized in that: Before removing the front support grouting steel pipe (1), the front support grouting steel pipe (1) should be struck several times with a hammer to break the cement slurry shell solidified on the surface of the front support grouting steel pipe (1).

4. A method for early removal of front support grouting steel pipe according to claim 1, characterized in that: The cement slurry shell falling from the surface of the front support grouting steel pipe (1) is collected by a broom, a shovel and a trash can and put into the trash can.

5. The method for early removal of front support grouting steel pipe according to claim 1, characterized in that: The mechanical dismantling uses a cutting machine to cut off the two ring beams (2) and the plurality of connecting beams (3) and pile them together.

6. The method for early removal of front support grouting steel pipe according to claim 1, characterized in that: After the ring beam (2) and the plurality of connecting beams (3) are cut, the plurality of front support grouting steel pipes (1) are cut in sections.

7. The method for early removal of front support grouting steel pipe according to claim 1, characterized in that: After the two ring beams (2), the plurality of connecting beams (3) and the plurality of front support grouting steel pipes (1) are completely dismantled and the two ring beams (2), the plurality of connecting beams (3) and the plurality of front support grouting steel pipes (1) are neatly arranged, the two ring beams (2), the plurality of connecting beams (3) and the plurality of front support grouting steel pipes (1) are then tied together using hemp ropes.

8. The method for early removal of front support grouting steel pipe according to claim 1, characterized in that: The two ring beams (2), a plurality of connecting beams (3) and a plurality of front support grouting steel pipes (1) are lifted and removed from the foundation pit by a crane after being tied with hemp ropes.

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