A method for dismantling foundation pit slope support structure

Abstract

The present invention discloses a method for dismantling a foundation pit slope support structure, comprising the following steps: installing a plurality of steel beam layers from top to bottom in sequence between the slope of the upper part of the foundation pit and the main structure of the basement, each steel beam layer comprising a plurality of steel beams fixed between the slope and the main structure of the basement, removing the spray anchor support located above the steel beam layer after each steel beam layer is completed, and installing the next steel beam layer after the removal is completed; pouring the basement external bearing wall between the pit wall at the lower part of the foundation pit and the main structure of the basement, installing a bearing top beam on the top of the basement external bearing wall, and connecting the two ends of the bearing top beam to the supporting piles on the main structure of the basement and the pit wall respectively; removing the supporting piles not connected to the bearing top beam, and then pouring the basement external bearing wall for a second time. The present invention can improve the deficiencies of the prior art and improve the efficiency of foundation pit support removal under the premise of ensuring construction safety.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, in particular to a method for dismantling a foundation pit slope support structure. Background Art

[0002] With the continuous development of urban construction, the construction land in the city is becoming increasingly tight. By making greater use of underground space, the problem of tight construction land can be effectively alleviated. At this time, it is necessary to excavate larger and deeper foundation pits for underground space construction. At the same time, there are many buildings around the construction site in the city. When excavating the foundation pit, it is usually necessary to reinforce the foundation pit through various methods such as slope reduction and support to ensure construction safety. After the main body of the underground space structure is poured, the support structure of the foundation pit needs to be removed for the construction of subsequent structures. At the same time, the support equipment can be recycled to achieve the purpose of recycling. Since the process of removing the foundation pit support will affect the stability of the foundation pit and the buildings around the foundation pit, the removal of the support is inefficient and takes a long time. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for dismantling a foundation pit slope support structure, which can solve the deficiencies of the prior art and improve the efficiency of foundation pit support dismantling while ensuring construction safety.

[0004] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0005] A method for dismantling a foundation pit slope support structure comprises the following steps:

[0006] Several layers of steel beams are installed from top to bottom between the slope of the upper part of the foundation pit and the main structure of the basement. Each layer of steel beams contains several steel beams fixed between the slope and the main structure of the basement. After each layer of steel beams is completed, the sprayed anchor support above the steel beam layer is removed. After the removal is completed, the next layer of steel beams is installed.

[0007] The external load-bearing wall of the basement is cast between the pit wall at the bottom of the foundation pit and the main structure of the basement. A load-bearing top beam is installed on the top of the external load-bearing wall of the basement. The two ends of the load-bearing top beam are respectively connected to the supporting piles on the main structure of the basement and the pit wall; the supporting piles not connected to the load-bearing top beam are removed, and then the external load-bearing wall of the basement is cast for the second time.

[0008] Preferably, the distance between the top steel beam layer and the top of the slope is 2 to 3 meters, and the distance between two adjacent steel beam layers is 2 to 3 meters. After completing one steel beam layer, a temporary floor is laid on the current steel beam layer, and then the slope is symmetrically divided into several construction areas. The sprayed anchor support is simultaneously dismantled in the symmetrical construction areas, and the temporary floor is removed after the dismantling operation is completed.

[0009] Preferably, after completing the installation of the next layer of steel beams, the temporary floor is removed from the current position and laid on the next layer of steel beams, and then the sprayed anchor support is removed, and then the support beams are installed between the steel beam layer with the temporary floor and the adjacent upper steel beam layer.

[0010] Preferably, a construction passage is preset on the external load-bearing wall of the basement, and the construction passage is staggered with the load-bearing top beam.

[0011] Preferably, the external load-bearing wall of the basement includes an outer wall and an inner wall, and brickwork layers are arranged on the outer sides of the outer wall and the inner wall; the outer wall includes an outer steel bar portion and an outer concrete casting portion, and the inner wall includes an inner steel bar portion and an inner concrete casting portion, and the outer steel bar portion and the inner steel bar portion are tied and connected by binding wire.

[0012] As a preferred method, the pouring process of the basement external load-bearing wall is as follows:

[0013] Make the outer reinforcement part, lay the bottom reinforcement, erect the main reinforcement on the bottom reinforcement, and then tie the horizontal distribution reinforcement to the main reinforcement;

[0014] Make the inner reinforcement part, lay the bottom reinforcement, erect the main reinforcement on the bottom reinforcement, and then tie the horizontal distribution reinforcement to the main reinforcement;

[0015] Perform secondary tying between the outer reinforcement portion and the inner reinforcement portion by tying wire;

[0016] Install the casting formwork outside the outer reinforcement part, and then cast the outer concrete casting part; remove the casting formwork after the casting is completed;

[0017] After the removal of the supporting piles is completed, the binding state of the binding wire is adjusted, and then the secondary pouring of the outer load-bearing wall of the basement is carried out; specifically, the pouring formwork is installed outside the inner steel bar part, and then the inner concrete pouring part is poured; after the pouring is completed, the pouring formwork is removed;

[0018] Finally lay the brickwork layer.

[0019] Preferably, when performing secondary binding between the outer steel bar portion and the inner steel bar portion, the binding wires are crossed between the outer steel bar portion and the inner steel bar portion, and a binding adjuster is provided at the intersection of the binding wires, and the binding state of the binding wires is adjusted by the binding adjuster; the binding adjuster includes two shells, which are fixedly connected by a support rod, and two buckles are provided inside the shell through an adjusting screw, and a slide groove is provided on the top of the adjusting screw, and the buckle is movably clamped in the slide groove, and the buckle is clamped and fixed on the binding wire.

[0020] Preferably, the position of the buckle in the shell is changed by rotating the adjusting screw, thereby changing the pulling force of the binding wire at different positions, thereby achieving the release of local stress on the inner steel bar portion.

[0021] The beneficial effects brought about by adopting the above technical solution are: the present invention is efficient and safe in removing the support during the process of underground structure reconstructing, and the overall stability of the underground structure is improved by optimizing the reconstructing structure and reconstructing construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view of a foundation pit in an embodiment of the present invention.

[0023] Figure 2 It is a cross-sectional view of the foundation pit after the support and removal work of the slope-laying part is completed in the embodiment of the present invention.

[0024] Figure 3 It is a cross-sectional view of the foundation pit after the support and removal work of the pit wall part is completed in the embodiment of the present invention.

[0025] Figure 4 It is a partial enlarged view of the top view of the external load-bearing wall and the load-bearing top beam of the basement in the embodiment of the present invention.

[0026] Figure 5 It is a structural diagram of the external load-bearing wall of the basement in an embodiment of the present invention.

[0027] Figure 6 is a structural diagram of a lashing adjuster in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Reference Figure 1 This example is a foundation pit support and demolition project of our company in Zhengzhou City. The foundation pit is 14.27 meters deep and roughly rectangular. The upper part of the foundation pit is a 5-meter-high slope, which is supported by sprayed anchors, and the part below the slope is supported by pile rows.

[0029] Reference Figure 2-3 The overall process of dismantling the support is to dismantle it step by step from top to bottom, first dismantle the sprayed anchor support for slope release, and then dismantle the pile support below. By combining the backfill construction of the basement with the support removal construction, we not only improve the stability of the foundation pit during the support removal process, but also effectively improve the construction efficiency. The specific steps include:

[0030] Two steel beam layers 4 are installed from top to bottom between the slope 2 at the top of the foundation pit and the main structure 1 of the basement. Each steel beam layer 4 includes a number of steel beams 6 fixed between the slope 2 and the main structure 1 of the basement. After each layer of steel beam layer 4 is completed, the sprayed anchor support (not shown in the figure) located above the steel beam layer 4 is removed, and after the removal is completed, the next layer of steel beam layer 4 is installed.

[0031] Specifically, the distance between the top steel beam layer 4 and the top of the slope 2 is 2 meters, and the distance between two adjacent steel beam layers 4 is 3 meters. After the top steel beam layer 4 is completed, a temporary floor is laid on the top steel beam layer 4, and then the slope is symmetrically divided into several construction areas. The sprayed anchor support is removed simultaneously in the symmetrical construction areas. After the sprayed anchor support removal operation above the top steel beam layer 4 is completed, the bottom steel beam layer 4 is installed, and then the temporary floor is taken from the top and laid on the bottom steel beam layer 4, and the sprayed anchor support of the bottom is removed. Finally, the support beam 9 is installed between the top steel beam layer 4 and the bottom steel beam layer 4.

[0032] By setting two layers of steel beam layers 4, the slope area is well supported laterally, and then the spray anchor support is removed in sections to reduce the disturbance to the slope earthwork. At the same time, by setting the steel beam layer 4, the construction workers can work on the steel beam layer 4 with the floor laid, which is convenient for the construction work of the workers, as well as the handling of equipment and disassembled support parts, which can effectively increase the number of construction workers and improve the construction speed. Finally, by installing the support beam 9, the entire steel beam structure is formed into a whole, which is used to improve the overall strength of the basement structure.

[0033] After the support removal of the slope part is completed, the support removal of the pit wall part begins. For the removal of the support piles 8, we did not take the approach of removing all of them, but retained a small part of the support piles 8 and the basement external load-bearing wall 5 for backbuilding. This not only improves the safety of the support removal, but also avoids the need to reinforce the foundation pit wall 3 again when pouring the basement external load-bearing wall 5.

[0034] An external load-bearing wall 5 of the basement is cast between the pit wall 3 at the lower part of the foundation pit and the main structure 1 of the basement. Several load-bearing top beams 7 are installed on the top of the external load-bearing wall 5 of the basement. The two ends of the load-bearing top beams 7 are respectively connected to the supporting piles 8 on the main structure 1 of the basement and the pit wall 3; the supporting piles 8 not connected to the load-bearing top beams 7 are removed (the number of supporting piles 8 is much greater than the number of load-bearing top beams 7), and then the external load-bearing wall 5 of the basement is cast for the second time.

[0035] Specific reference Figure 4 A construction passage 10 is preset on the outer load-bearing wall 5 of the basement, and the construction passage 10 is staggered with the load-bearing top beam 7. The construction passage 10 is used for construction personnel to enter and exit, so as to remove the support piles 8. Since the outer load-bearing wall 5 of the basement plays a good supporting role on the foundation pit, when removing the support piles 8, multiple groups of construction personnel can perform the removal work synchronously at different positions, which is highly efficient. Because there is a steel beam layer 4 reinforced above the foundation pit, multiple groups of synchronous cutting and removal can be performed during the removal of the support piles 8, which will not affect the slope 2 on the upper part of the foundation pit.

[0036] Reference Figure 5 The basement external load-bearing wall 5 includes an outer wall 11 and an inner wall 12, and a brickwork layer 13 is arranged on the outer side of the outer wall 11 and the inner wall 12; the outer wall 11 includes an outer steel bar portion 14 and an outer concrete pouring portion 15, and the inner wall 12 includes an inner steel bar portion 16 and an inner concrete pouring portion 17, and the outer steel bar portion 14 and the inner steel bar portion 16 are tied and connected by a binding wire 18. The basement external load-bearing wall 5 adopts an inner and outer two-layer design and is cast twice. This structural design can effectively avoid damage to the structure of the basement external load-bearing wall 5 when cutting the support piles 8.

[0037] The pouring process of the basement external load-bearing wall 5 is as follows:

[0038] Make the outer reinforcement part 14, lay the bottom reinforcement, erect the main reinforcement on the bottom reinforcement, and then tie the horizontal distribution reinforcement to the main reinforcement;

[0039] Make the inner reinforcement part 16, lay the bottom reinforcement, erect the main reinforcement on the bottom reinforcement, and then tie the horizontal distribution reinforcement to the main reinforcement;

[0040] A secondary binding is performed between the outer reinforcement portion 14 and the inner reinforcement portion 16 by means of a binding wire 18;

[0041] Install a casting template outside the outer reinforcement part 14, and then cast the outer concrete casting part 15; remove the casting template after the casting is completed;

[0042] After the removal of the support piles 8 is completed, the binding state of the binding wires 18 is adjusted, and then the secondary pouring of the outer load-bearing wall 5 of the basement is carried out; specifically, the pouring template is installed outside the inner steel bar part 16, and then the inner concrete pouring part 17 is poured; after the pouring is completed, the pouring template is removed;

[0043] Finally, the brickwork layer 13 is laid.

[0044] During the removal of the supporting piles 8 , the vibration caused by the cutting and the local stress changes caused by the fracture process of the supporting piles 8 themselves will cause slight deformation and internal stress changes in the outer wall 11 , which will be transmitted to the inner steel bar portion 16 through the steel bars.

[0045] Reference Figure 6When the secondary binding is performed between the outer steel bar portion 14 and the inner steel bar portion 16, the binding wire 18 crosses between the outer steel bar portion 14 and the inner steel bar portion 16, and a binding regulator 19 is provided at the intersection of the binding wire 18, and the binding regulator 19 is used to adjust the binding state of the binding wire 18; the binding regulator 19 includes two housings 20, and the two housings 20 are fixedly connected by a support rod 21, and two buckles 22 are provided inside the housing 20 through an adjusting screw 23, and a slide groove (not shown in the figure) is provided at the top of the adjusting screw 23, and the buckle 22 is movably connected in the slide groove, and the buckle 22 is fixed on the binding wire 18. The position of the buckle 22 in the housing 20 is changed by rotating the adjusting screw 23, thereby changing the pulling force of different positions of the binding wire 18, and realizing the release of the local stress of the inner steel bar portion 16. Among them, first adjust the two adjusting screws 23 close to the outer wall 11 to keep the binding force of different binding wires 18 basically consistent, and then adjust the two adjusting screws 23 on the other side to keep the binding force of the binding wires 18 on both sides of each binding adjuster 19 basically consistent.

[0046] After the second binding, the local stress can be effectively released, and the inner steel bar part 16 can be adjusted to the optimal binding support state. Then, the inner concrete pouring part 17 can be poured, so that the entire basement external load-bearing wall 5 can be evenly stressed, thereby improving the stability of the entire basement structure.

[0047] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0048] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for dismantling a foundation pit slope support structure, characterized in that The following steps are involved: Several layers of steel beams are installed from top to bottom between the slope of the upper part of the foundation pit and the main structure of the basement. Each layer of steel beams contains several steel beams fixed between the slope and the main structure of the basement. After each layer of steel beams is completed, the sprayed anchor support above the steel beam layer is removed. After the removal is completed, the next layer of steel beams is installed. The external load-bearing wall of the basement is poured between the pit wall at the bottom of the foundation pit and the main structure of the basement. A load-bearing top beam is installed on the top of the external load-bearing wall of the basement. The two ends of the load-bearing top beam are respectively connected to the supporting piles on the main structure of the basement and the pit wall; the supporting piles not connected to the load-bearing top beam are removed, and then the external load-bearing wall of the basement is poured for the second time; The pouring process of the basement external load-bearing wall is as follows: Make the outer reinforcement part, lay the bottom reinforcement, erect the main reinforcement on the bottom reinforcement, and then tie the horizontal distribution reinforcement to the main reinforcement; Make the inner reinforcement part, lay the bottom reinforcement, erect the main reinforcement on the bottom reinforcement, and then tie the horizontal distribution reinforcement to the main reinforcement; Perform secondary tying between the outer reinforcement portion and the inner reinforcement portion by tying wire; Install the casting formwork outside the outer reinforcement part, and then cast the outer concrete casting part; remove the casting formwork after the casting is completed; After the removal of the supporting piles is completed, the binding state of the binding wire is adjusted, and then the secondary pouring of the outer load-bearing wall of the basement is carried out; specifically, the pouring formwork is installed outside the inner steel bar part, and then the inner concrete pouring part is poured; after the pouring is completed, the pouring formwork is removed; Finally lay the brickwork layer.

2. The method for dismantling the foundation pit slope support structure according to claim 1, characterized in that: The distance between the top steel beam layer and the top of the slope is 2 to 3 meters, and the distance between two adjacent steel beam layers is 2 to 3 meters. After completing one steel beam layer, a temporary floor is laid on the current steel beam layer, and then the slope is symmetrically divided into several construction areas. The sprayed anchor support is dismantled simultaneously in the symmetrical construction areas, and the temporary floor is removed after the dismantling work is completed.

3. The method for dismantling the foundation pit slope support structure according to claim 2, characterized in that: After completing the installation of the next steel beam layer, the temporary floor is removed from the current position and laid on the next steel beam layer, and then the sprayed anchor support is removed, and then the support beams are installed between the steel beam layer with the temporary floor and the adjacent steel beam layer above it.

4. The method for dismantling the foundation pit slope support structure according to claim 1, characterized in that: A construction passage is preset on the external load-bearing wall of the basement, and the construction passage is staggered with the load-bearing top beam.

5. The method for dismantling the foundation pit slope support structure according to claim 4, characterized in that: The outer load-bearing wall of the basement includes an outer wall and an inner wall, and brickwork layers are arranged on the outer sides of the outer wall and the inner wall; the outer wall includes an outer steel bar portion and an outer concrete pouring portion, and the inner wall includes an inner steel bar portion and an inner concrete pouring portion, and the outer steel bar portion and the inner steel bar portion are tied and connected by binding wire.

6. The method for dismantling the foundation pit slope support structure according to claim 5, characterized in that: When performing secondary binding between the outer steel bar portion and the inner steel bar portion, the binding wires cross between the outer steel bar portion and the inner steel bar portion, and a binding adjuster is provided at the intersection of the binding wires, and the binding state of the binding wires is adjusted by the binding adjuster; the binding adjuster includes two shells, which are fixedly connected by a support rod, and two buckles are provided inside the shell through an adjusting screw, and a slide groove is provided on the top of the adjusting screw, and the buckle is movably clamped in the slide groove, and the buckle is clamped and fixed on the binding wire.

7. The method for dismantling the foundation pit slope support structure according to claim 6, characterized in that: The position of the buckle in the shell is changed by rotating the adjusting screw, thereby changing the pulling force of the binding wire at different positions, thereby releasing the local stress of the inner steel bar part.

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