Construction method of thin-wall closed-end bearing platform structure

Abstract

The present invention discloses a thin-walled closed-mouth type pile cap structure and a construction method. The thin-walled closed-mouth type pile cap structure is surrounded by precast thin shells on all sides and filled with slurry inside the precast thin shells. Openings are respectively arranged at the top and bottom of the precast thin shells; the area of the top opening of the precast thin shell is smaller than the area of the bottom opening, forming a closed-mouth type pile cap structure with a large bottom area and a small top area. The construction method includes first driving a retaining wall at the construction position, then excavating a foundation pit in the area enclosed by the retaining wall, and finally pouring concrete at the bottom of the foundation pit to form a cushion layer and placing a bottom steel mesh on the cushion layer. Without affecting the bearing capacity of the pile cap structure, the present invention can save the amount of concrete slurry and steel bars of the pile cap structure, thus saving construction costs; it can reduce the size of the foundation pit. After the construction of the pile cap structure is completed, the ratio of backfill soil increases, so the construction waste is reduced, thereby improving the construction efficiency to a certain extent.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and particularly to a thin-walled closed-end pile cap structure and a construction method thereof. Background Art

[0002] In the prior art, for the convenience of on-site construction in bridge construction, the pile cap structure is usually made into a square or other shapes, and the top and bottom surfaces of the pile cap adopt the same cross-sectional form. However, from the perspective of force, such a structural design not only causes waste of the amount of pile cap concrete, but also requires a large amount of foundation pit excavation during construction, resulting in a large amount of construction waste during the construction process. The treatment of the construction waste increases the construction volume to a certain extent, thereby reducing the construction efficiency.

[0003] Therefore, how to optimize the structural volume of the pile cap, reduce the amount of pile cap concrete, and reduce the generation of construction waste during the construction process has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0004] In view of the above-mentioned defects of the prior art, the technical object of the present invention is to optimize the structural volume of the pile cap so as to reduce the amount of pile cap concrete used to save construction costs and reduce the generation of construction waste to improve construction efficiency.

[0005] To achieve the above technical object, the present invention provides a thin-walled closed-end pile cap structure, which is surrounded by precast thin shells on all sides and filled with slurry inside the precast thin shells. Openings are respectively provided at the top and bottom of the precast thin shells;

[0006] Among them, the area of the top opening of the precast thin shell is smaller than the area of the bottom opening, forming a closed-end pile cap structure with a large bottom area and a small top area;

[0007] Steel mesh sheets are respectively arranged around the inside of the precast thin shell, at the top opening of the precast thin shell, and at the bottom opening of the precast thin shell, and adjacent steel mesh sheets are fixedly connected;

[0008] At the bottom of the steel mesh sheet located at the bottom opening of the precast thin shell, a cushion layer is provided for sealing the bottom opening of the precast thin shell.

[0009] Preferably, the precast thin shell is composed of two segments, a bottom segment and a top segment. The bottom segment is a vertical segment, and the top segment extends obliquely from the top of the bottom segment to the edge of the top opening.

[0010] Preferably, the steel mesh sheets arranged around the inside of the precast thin shell, at the top opening of the precast thin shell, and at the bottom opening of the precast thin shell are respectively an inner-shell steel mesh, a top steel mesh, and a bottom steel mesh.

[0011] Preferably, the ends of the steel bar mesh inside the shell extend out of the precast thin shell.

[0012] Preferably, the precast thin shell is composed of several precast plates.

[0013] The present invention also provides a construction method for the above-mentioned thin-wall closed-end cap structure, including the following steps:

[0014] Step 1: First, drive the retaining wall at the construction location, then excavate a foundation pit in the area enclosed by the retaining wall, and finally pour concrete at the bottom of the foundation pit to form a cushion layer, and place the bottom steel bar mesh on the cushion layer;

[0015] Step 2: First, hoist the precast thin shell onto the bottom steel bar mesh so that the bottom opening of the precast thin shell corresponds to the bottom steel bar mesh, and then use supports to keep the precast thin shell stable;

[0016] Step 3: First, tie the steel bar mesh inside the shell at the end of the bottom steel bar mesh, and then tie the top steel bar mesh at the end of the steel bar mesh inside the shell;

[0017] Step 4: First, arrange counterweights on the inclined surface of the precast thin shell, and then pour concrete at the top opening of the precast thin shell to form a cap structure;

[0018] Step 5: Finally, backfill the foundation pit, and pull out the retaining wall after the backfill is completed.

[0019] Preferably, the retaining wall is a U-shaped steel sheet pile.

[0020] Preferably, the support is composed of a support plate and two inclined support arms. One ends of the two inclined support arms are respectively fixed to the support plate, and the other ends respectively extend obliquely towards the outside of the support plate.

[0021] Advantages of the present invention:

[0022] For the thin-wall closed-end cap structure of the present invention, without affecting the bearing capacity of the cap structure, it can save the concrete slurry and steel bar consumption of the cap structure, thus saving the construction cost.

[0023] The construction method of the present invention can reduce the size of the foundation pit. After the construction of the cap structure is completed, the ratio of backfill soil increases, so the construction waste is reduced, thereby improving the construction efficiency to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a three-dimensional structural schematic diagram of an embodiment of the thin-wall closed-end cap structure of the present invention;

[0025] Figure 2 is a front structural schematic diagram of an embodiment of the thin-wall closed-end cap structure of the present invention;

[0026] Figure 3 This is a schematic top view of a thin-walled closed-mouth type pile cap structure according to an embodiment of the present invention;

[0027] Figure 4 This is a construction schematic diagram of Step 1 of an embodiment of the construction method of the present invention;

[0028] Figure 5 This is a construction schematic diagram of Step 2 of an embodiment of the construction method of the present invention;

[0029] Figure 6 This is a construction schematic diagram of Step 3 of an embodiment of the construction method of the present invention;

[0030] Figure 7 This is a construction schematic diagram of Step 4 of an embodiment of the construction method of the present invention;

[0031] Figure 8 This is a construction schematic diagram of Step 5 of an embodiment of the construction method of the present invention.

[0032] In the figure: 1 concrete cushion, 2 precast thin shell, 3 bottom steel mesh, 4 top steel mesh, 5 steel mesh inside the shell, 6 protective arm, 7 support, 8 weight block. Specific embodiments

[0033] The following will further illustrate the concept, specific structure and technical effects of the present invention with reference to the accompanying drawings to fully understand the purpose, features and effects of the present invention.

[0034] Embodiment:

[0035] As Figures 1-3 shown, the thin-walled closed-mouth type pile cap structure is surrounded by precast thin shells 2 on all sides and filled with slurry inside the precast thin shells 2. Openings are respectively provided at the top and bottom of the precast thin shells 2;

[0036] Among them, the area of the top opening of the precast thin shell 2 is smaller than the area of the bottom opening, forming a closed-mouth pile cap structure with a large bottom area and a small top area;

[0037] Steel mesh sheets are respectively arranged around the inside of the precast thin shell 2, at the top opening of the precast thin shell 2, and at the bottom opening of the precast thin shell 2, and adjacent steel mesh sheets are fixedly connected;

[0038] At the bottom of the steel mesh sheet located at the bottom opening of the precast thin shell 2, a cushion ① is provided for sealing the bottom opening of the precast thin shell 2.

[0039] More specifically, in order to enable the pile cap structure to form a closed-mouth shape with a large bottom and a small top, the precast thin shell 2 can be composed of two segments, a bottom segment and a top segment. The bottom segment is a vertical segment, and the top segment extends obliquely from the top of the bottom segment to the edge of the top opening;

[0040] The precast thin shell 2 can also be integrally formed into an arc shape.

[0041] The steel mesh sheets arranged around the inner periphery of the precast thin shell 2, at the top opening of the precast thin shell 2, and at the bottom opening of the precast thin shell 2 are respectively the inner shell steel mesh 5, the top steel mesh 4, and the bottom steel mesh 3.

[0042] In order to facilitate the fixed binding between the inner shell steel mesh 5 and the top steel mesh 4 and the bottom steel mesh 3, the end of the inner shell steel mesh 5 extends out of the precast thin shell 2.

[0043] In order to facilitate the fabrication and transportation of the precast thin shell 2, the precast thin shell 2 is composed of several precast slabs, which can be precast in blocks in the factory and finally assembled into a whole on site.

[0044] As Figures 4-8 shown, the construction method of the above-mentioned thin-wall closed-end pile cap structure includes the following steps:

[0045] Step 1: First, drive U-shaped steel sheet piles at the construction position as the retaining wall 6, then excavate a foundation pit in the area enclosed by the retaining wall 6, and finally pour concrete at the bottom of the foundation pit to form a cushion 1, and place the bottom steel mesh 3 on the cushion 1;

[0046] Step 2: First, hoist the precast thin shell 2 onto the bottom steel mesh 3 so that the bottom opening of the precast thin shell 2 corresponds to the bottom steel mesh 3, and then use the support 7 to keep the precast thin shell 2 stable;

[0047] Step 3: First, bind the inner shell steel mesh 5 at the end of the bottom steel mesh 3, and then bind the top steel mesh 4 at the end of the inner shell steel mesh 5;

[0048] Step 4: First, arrange the counterweight blocks 8 on the inclined surface of the precast thin shell 2, and then pour concrete at the top opening of the precast thin shell 2 to form a pile cap structure;

[0049] Step 5: Finally, backfill the foundation pit, and pull out the retaining wall after the backfill is completed.

[0050] Further, in order to ensure the stability of the precast thin shell 2 when it is supported, the support 7 is composed of a support plate and two inclined support arms. One ends of the two inclined support arms are respectively fixed to the support plate, and the other ends respectively extend obliquely towards the outside of the support plate.

[0051] To sum up: The pile cap structure of the present invention presents a tension-compression bar state during the stress process, with the concrete between the pile foundation and the pile cap structure as the compression bar, the bottom steel mesh 3 forming the tension bar, and the top of the pile cap structure forming an inclined surface, which does not affect the bearing capacity of the pile cap structure but can save the concrete and steel usage of the pile cap structure.

[0052] The construction method of the present invention only uses the precast thin shell 2 as a formwork, which can conveniently realize the casting and forming of the inclined pile cap structure. Since no other construction formwork is required and no space for formwork installation and disassembly needs to be reserved, the size of the foundation pit can be reduced. Since the size is smaller than that of the traditional pile cap structure, the ratio of backfill soil increases after the construction of the pile cap structure, so the construction waste is reduced.

[0053] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should fall within the protection scope determined by the claims.

Claims

1. Construction method of thin-walled necking type bearing platform structure. The periphery of the thin-walled necking type bearing platform structure is enclosed by precast thin shells, and slurry is poured inside the precast thin shells. Openings are respectively arranged at the top and bottom of the precast thin shells; Among them, The opening area at the top of the precast thin shell is smaller than the opening area at the bottom, forming a necking type bearing platform structure with a large bottom area and a small top area; Steel mesh sheets are respectively arranged around the inside of the precast thin shell, at the top opening of the precast thin shell, and at the bottom opening of the precast thin shell. Adjacent steel mesh sheets are fixedly connected; At the bottom of the steel mesh sheet located at the bottom opening of the precast thin shell, a cushion layer is provided for sealing the bottom opening of the precast thin shell; The precast thin shell is composed of two segments, namely a bottom segment and a top segment. The bottom segment is a vertical segment, and the top segment extends obliquely from the top of the bottom segment to the edge of the top opening; The steel mesh sheets arranged around the inside of the precast thin shell, at the top opening of the precast thin shell, and at the bottom opening of the precast thin shell are respectively an in-shell steel mesh, a top steel mesh, and a bottom steel mesh; The end of the in-shell steel mesh extends out of the precast thin shell; The precast thin shell is composed of several precast plates; The construction method includes the following steps: Step 1: First, drive the retaining wall at the construction position, then excavate a foundation pit in the area enclosed by the retaining wall, and finally pour concrete at the bottom of the foundation pit to form a cushion layer, and place the bottom steel mesh on the cushion layer; Step 2: First, hoist the precast thin shell onto the bottom steel mesh, make the bottom opening of the precast thin shell correspond to the bottom steel mesh, and then use supports to keep the precast thin shell stable; Step 3: First, tie the in-shell steel mesh at the end of the bottom steel mesh, and then tie the top steel mesh at the end of the in-shell steel mesh; Step 4: First, arrange counterweights on the inclined surface of the precast thin shell, and then pour concrete at the top opening of the precast thin shell to form the bearing platform structure; Step 5: Finally, backfill the foundation pit, and pull out the retaining wall after the backfill is completed.

2. The construction method of the thin-walled closed-end pile cap structure according to claim 1, characterized in that: The retaining wall is a U-shaped steel sheet pile.

3. The construction method of the thin-wall closed-end pile cap structure according to claim 1 or 2, characterized in that: The support is composed of a support plate and two inclined support arms. One ends of the two inclined support arms are respectively fixed to the support plate, and the other ends respectively extend obliquely towards the outside of the support plate.

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