Thick pebble bed cast-in-place pile steel casing

Abstract

The utility model discloses a thick pebble bed cast-in-place pile steel casing which is fixedly located on the periphery of a cast-in-place pile reinforcement cage within the range of a pebble bed and comprises a plurality of steel casing meshes which are sequentially spliced from bottom to top, and the steel casing meshes are of an arc-shaped shell type structure. The same section of the cast-in-place pile reinforcement cage is enclosed by one or more steel casing meshes in a concentric splicing mode, each steel casing mesh comprises a mesh frame, superimposed steel wire meshes are bound and fixed to the two sides of the mesh frame, the mesh frame is connected with the cast-in-place pile reinforcement cage in a bound mode, and the steel casing meshes are connected with the cast-in-place pile reinforcement cage. The utility model provides a structure which can be conveniently transported and assembled, a good enclosing and supporting effect can be formed in a pile hole in the range of a pebble bed, and the superimposed steel wire mesh and the mesh frame on the steel casing mesh can well prevent the peripheral wall of the pile hole from collapsing again.

Description

Technical Field

[0001] The utility model relates to the field of cast-in-place pile construction, and more specifically, to a steel casing for cast-in-place piles in thick pebble layers. Background Art

[0002] In the construction of building pile foundation, bored pile is used as a construction method with an increasingly wide scope of construction. The gravel stratum is a typical mechanically unstable stratum with loose structure and large porosity. When bored pile is constructed in this site environment, it is difficult to use mud wall protection to prevent hole collapse. The most commonly used method is to use a steel sleeve to follow up the drilling or to press the steel sleeve into the hole first and then form the hole. After the pouring is completed, the steel sleeve is pulled out. The steel sleeve is surrounded and welded by a steel plate with a wall thickness of more than 10 mm. In the thick pebble layer stratum, especially when constructing a large-diameter bored pile, after the steel sleeve is pulled out, the supporting force of the hole wall of the pebble layer is weakened, and secondary hole collapse is prone to occur, which leads to a reduction in the bearing capacity of the bored pile or the pile is abandoned. If the steel sleeve is not pulled out and is formed together with the pile body concrete, the cost is too high, especially when facing a large range of thick pebble sites, each processing of a steel sleeve will increase a large amount of welding work.

[0003] In the patent application announcement number CN109056735A, a leak-proof concrete device for bored cast-in-place piles encountering karst caves is disclosed. By adding an outer casing outside the steel cage, the problem of leakage of bored cast-in-place piles in the karst cave area during concrete pouring construction is solved. However, in this method, the outer casing is a closed structure, which is inconvenient to connect and install with the steel cage. In addition, the application scenario is a karst cave scenario, which is different from a thick pebble layer. Therefore, it is necessary to propose a new steel casing for bored cast-in-place piles in a thick pebble layer. Utility Model Content

[0004] One purpose of the utility model is to provide a steel casing for a thick pebble layer bored pile, which can be suitable for thick pebble layer working conditions, has a good anti-collapse effect on the bored pile after pouring, and is easy to install.

[0005] In order to achieve these purposes and other advantages of the utility model, according to one aspect of the utility model, a thick pebble layer cast-in-place pile steel casing is provided, which is fixed to the outer periphery of the cast-in-place pile reinforcement cage within the pebble layer, and is characterized in that it includes:

[0006] A plurality of steel casing meshes are sequentially assembled from bottom to top to form a cylinder, wherein the steel casing meshes are arc-shaped shell-shaped structures, and the same segment of the cast-in-place pile reinforcement cage is enclosed by a plurality of steel casing meshes concentrically assembled and assembled, and the steel casing meshes include a mesh frame, and the inner and outer sides of the mesh frame are bound and fixed with overlapping steel wire meshes, and any two adjacent mesh frames are detachably connected, and the mesh frame is bound and connected to the cast-in-place pile reinforcement cage.

[0007] Preferably, the cross section of the steel casing mesh is a quarter arc segment, and the same segment of the cast-in-place pile reinforcement cage is enclosed by four steel casing meshes of the same size.

[0008] Preferably, the mesh frame includes a plurality of mutually connected frame transverse frames and frame vertical frames, and the laminated steel wire mesh includes an inner steel wire mesh and an outer steel wire mesh sequentially bound to the mesh frame from inside to outside.

[0009] Preferably, the frame transverse frame and the frame vertical frame are provided with wire binding holes at intervals, and the inner steel wire mesh and the outer steel wire mesh are fixed to the mesh frame by binding through the wire binding holes.

[0010] Preferably, mesh connecting bolt holes are provided in the upper and lower frame cross frames and the frames on both sides of the mesh frame, and any two adjacent steel casing meshes are bolted together.

[0011] Preferably, a plurality of positioning ribs are fixed to the inner side of the mesh frame, and the positioning ribs are tied and fixed to the cast-in-place pile reinforcement cage.

[0012] Preferably, the inner steel mesh and the outer steel mesh are both formed by overlapping more than one diamond-shaped steel plate mesh with staggered holes.

[0013] The utility model at least has the following beneficial effects:

[0014] First, the thick pebble layer cast-in-place pile steel casing provided by the utility model can form a good enclosed support effect on the pile hole in the pebble layer, and the superimposed steel wire mesh and mesh frame on the steel casing mesh can better prevent the pile hole peripheral wall from collapsing again;

[0015] Secondly, the thick pebble layer cast-in-place pile steel casing provided by the utility model can be tied with the overlapping steel wire mesh, mesh frame, and cast-in-place pile reinforcement cage by conventional binding wire, and the adjacent mesh frames are connected by bolts to maintain integrity. The steel casing mesh is assembled and lowered on the bottom surface, and the cast-in-place pile reinforcement cage is assembled and lowered synchronously. The installation is convenient and the weight is lighter than the conventional steel casing enclosed by steel plates.

[0016] Thirdly, the thick pebble layer cast-in-place pile steel casing provided by the utility model can be well combined with the mesh frame during the pouring and solidification of concrete or cement slurry.

[0017] Fourthly, the steel casing of the thick pebble layer cast-in-place pile provided by the utility model can be designed according to the thickness of the pebble layer without being arranged along the pile foundation, thus saving materials.

[0018] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and implementation examples:

[0020] Figure 1 It is a schematic diagram of the assembly of the utility model;

[0021] Figure 2 This is a schematic diagram of disassembling the steel casing mesh of the utility model;

[0022] Figure 3 This is a schematic diagram of the mesh frame of the utility model;

[0023] Figure 4 This is a top view of the utility model after assembly;

[0024] Figure 5 This is a schematic diagram of assembling the steel casing of the thick pebble layer cast-in-place pile of the utility model;

[0025] Figure 6 It is a schematic diagram of the work before pouring of the utility model.

[0026] Legend: 1- steel casing mesh, 10- mesh frame, 101- frame horizontal frame, 102- frame vertical frame, 11- laminated wire mesh, 111- inner wire mesh, 112- outer wire mesh, 12- mesh connection bolt holes, 13- wire binding holes, 14- positioning bars, 2- steel casing, 3- cast-in-place pile reinforcement cage, 4- pebble layer, 5- pile hole DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0028] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0029] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the components can be obtained from commercial channels unless otherwise specified; in the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected, set, or detachably connected, set, or connected and set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood in specific circumstances. The orientation or position relationship indicated by the terms "transverse", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present utility model and simplifying the description, and does 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 cannot be understood as a limitation to the present utility model.

[0030] like Figures 1 to 6As shown, the technical solution of the present application provides a steel casing for a thick pebble layer bored pile, which is fixed to the outer periphery of a bored pile reinforcement cage 3 within the scope of a pebble layer 4, and includes a plurality of steel casing meshes 1 which are sequentially assembled from bottom to top into a cylinder body, wherein the steel casing mesh 1 is an arc-shaped shell structure, and the same segment of the bored pile reinforcement cage 3 is concentrically assembled and enclosed by a plurality of steel casing meshes 1, and the steel casing mesh 1 includes a mesh frame 10, and a superimposed steel wire mesh 11 is tied and fixed on both sides of the mesh frame 10, and any two adjacent meshes are The mesh frame 10 is detachably connected, and the mesh frame 10 is tied to the bored pile reinforcement cage 3. In this technical solution, before the pile foundation is bored, the steel casing 2 is vertically pressed into the soil according to the conventional bored pile construction method, and then the soil inside the steel casing 2 is dug out by machinery. The bored pile reinforcement cage 3 is a reinforcement cage composed of longitudinal reinforcement and stirrups. Before installing the steel casing mesh 1, the steel casing mesh 1 needs to be designed according to the soil layer conditions recorded when pressing down the steel casing 2 and digging the soil therein. The installation position is such that after the steel casing mesh 1 is lowered with the cast-in-place pile reinforcement cage 3, it is just within the range of the pebble layer 4. The steel casing mesh 1 is an arc-shaped shell structure, which can be in the shape of a half arc, a third arc, or a quarter arc for easier transportation and more convenient on-site manual binding with the cast-in-place pile reinforcement cage 3. The mesh frame 10 is a frame structure composed of multiple horizontal arc plates and vertical straight plates. The mesh frame 10 is manually bound to the cast-in-place pile by steel binding wire. On the steel cage 3, any two adjacent mesh frames 10 are connected by steel binding wire or by setting bolt holes. The inner and outer sides of the mesh frame 10 are fixed with a laminated steel wire mesh 11. The laminated steel wire mesh 11 is composed of laminated steel wire mesh or steel plate mesh currently available on the market. The laminated steel wire mesh 11 can prevent pebbles or gravel with smaller particle sizes from entering the steel casing mesh 1. The mesh frame 10 has a certain strength, which can prevent the steel casing mesh 1 from buckling and damage, thereby achieving the purpose of supporting the hole wall.

[0031] In the present technical solution, the diameter of the cylinder structure composed of the steel casing mesh 1 is less than or equal to the inner diameter of the steel casing 2. The steel casing mesh 1 connected into sections enters the steel casing 2 under the bored pile reinforcement cage 3, and concrete is poured into the pile hole 5. Before the initial setting of the concrete, the steel casing 2 is pulled up and recovered and grouting is performed in the pile hole 5. At this time, if the pebble layer 4 peels off to a certain extent, the steel casing mesh 1 is used for support. Moreover, since the steel casing meshes 1 are assembled into a cylindrical structure and are tied to the internal bored pile reinforcement cage 3 as a whole, the steel casing mesh 1 does not suffer from serious deformation or damage. Even if the outermost layer of the laminated steel wire mesh 11 of the steel casing mesh 1 is deformed or damaged, the pebbles peeled off from the peripheral wall of the pile hole 5 will not enter the interior of the steel casing mesh 1, and the laminated steel wire mesh 11 can pass through concrete and cement slurry to form a protective layer formed by the steel casing mesh 1, peeled pebbles and cement slurry co-solidified on the outer periphery of the originally designed pile foundation. This structure avoids the situation where the pile foundation is prone to collapse after the steel casing 2 is issued in the conventional practice by adding the steel casing mesh 1, and can solve the cost increase caused by leaving the steel casing 2 in the pile hole 5 to avoid collapse.

[0032] In another technical solution, the cross-section of the steel casing mesh 1 is a quarter arc segment, and the same segment of the cast-in-place pile reinforcement cage 3 is enclosed by four steel casing meshes 1 of the same size. The steel casing mesh 1 is a quarter arc segment. After completing the binding of each section of the cast-in-place pile reinforcement cage 3, the four steel casing meshes are spliced ​​on the outer periphery of the cast-in-place pile reinforcement cage 3. The arc-shaped steel casing mesh 1 can be easily transported and on-site construction personnel can more easily perform binding work.

[0033] In another technical solution, the mesh frame 10 includes a plurality of interconnected frame transverse frames 101 and frame vertical frames 102, and the composite steel wire mesh 11 includes an inner steel wire mesh 111 and an outer steel wire mesh 112 sequentially tied to the mesh frame 10 from the inside to the outside. In this technical solution, the inner steel wire mesh 111 and the outer steel wire mesh 112 are fully tied to all the frame transverse frames 101 and the frame vertical frames 102 by binding wires, and the outer steel wire mesh 112 can be tied after the steel casing mesh 1 is positioned, tied and installed on the cast-in-place pile reinforcement cage 3 to avoid affecting the fixation of the steel casing mesh 1.

[0034] In another technical solution, the frame transverse frame 101 and the frame vertical frame 102 are spaced apart with wire binding holes 13, and the inner steel wire mesh 111 and the outer steel wire mesh 112 are fixed to the mesh frame 10 by binding through the wire binding holes. The wire binding holes 13 provide binding points for the inner steel wire mesh 111 and the outer steel wire mesh 112 to avoid displacement of the binding wire when directly binding to the frame transverse frame 101 and the frame vertical frame 102.

[0035] In another technical solution, the upper and lower frame cross frames 101 in the mesh frame 10 and the frames 102 on both sides are provided with mesh connecting bolt holes 12, and any two adjacent steel casing meshes 1 are bolted together. After any two steel casing meshes 1 are assembled, the uppermost and lowermost frame cross frames 101 are connected to the corresponding frame cross frames 101 of the adjacent steel casing meshes 1, and the mesh connecting bolt holes 12 correspond to each other, and are fixed by manually tightening the bolts.

[0036] In another technical solution, a plurality of positioning ribs 14 are fixed on the inner side of the mesh frame 10, and the positioning ribs 14 are tied and fixed to the cast-in-place pile reinforcement cage 3. The positioning ribs 14 are convex-shaped, and their two ends are welded to the vertical frame 102 of the frame, and the middle part is tied to the cast-in-place pile reinforcement cage 3 to fix the position of the steel casing mesh 1 and to ensure that the cast-in-place pile reinforcement cage 3 is always vertically centered.

[0037] In another technical solution, the inner steel mesh 111 and the outer steel mesh 112 are both composed of more than one diamond-shaped steel plate mesh with staggered holes, and the diamond-shaped steel plate mesh is a material available on the market.

[0038] The number of components and processing scale described here are used to simplify the description of the utility model. Applications, modifications and variations of the utility model are obvious to those skilled in the art.

[0039] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A steel casing for a cast-in-place pile in a thick pebble layer, which is fixed to the outer periphery of a cast-in-place pile reinforcement cage within the pebble layer, and is characterized in that: include: A plurality of steel casing meshes are sequentially assembled from bottom to top to form a cylinder, wherein the steel casing meshes are arc-shaped shell-shaped structures, and the same segment of the cast-in-place pile reinforcement cage is enclosed by a plurality of steel casing meshes concentrically assembled and assembled, and the steel casing meshes include a mesh frame, and the inner and outer sides of the mesh frame are bound and fixed with overlapping steel wire meshes, and any two adjacent mesh frames are detachably connected, and the mesh frame is bound and connected to the cast-in-place pile reinforcement cage.

2. The thick pebble layer cast-in-place pile steel casing as claimed in claim 1, characterized in that: The cross section of the steel casing mesh is a quarter arc segment, and the same segment of the cast-in-place pile reinforcement cage is enclosed by four steel casing meshes of the same size.

3. The thick pebble layer cast-in-place pile steel casing as claimed in claim 2, characterized in that: The mesh frame includes a plurality of mutually connected frame transverse frames and frame vertical frames, and the composite steel wire mesh includes an inner steel wire mesh and an outer steel wire mesh which are sequentially bound to the mesh frame from the inside to the outside.

4. The thick pebble layer cast-in-place pile steel casing as claimed in claim 3, characterized in that: The frame transverse frame and the frame vertical frame are spaced apart and provided with wire binding holes, and the inner steel wire mesh and the outer steel wire mesh are bound and fixed on the mesh frame through the wire binding holes.

5. The thick pebble layer cast-in-place pile steel casing as claimed in claim 4, characterized in that: The upper and lower frame cross frames in the mesh frame and the frames on both sides are provided with mesh connecting bolt holes, and any two adjacent steel casing meshes are connected by bolts.

6. The thick pebble layer cast-in-place pile steel casing as claimed in claim 5, characterized in that: A plurality of positioning bars are fixed on the inner side of the mesh frame, and the positioning bars are tied and fixed to the cast-in-place pile reinforcement cage.

7. The thick pebble layer cast-in-place pile steel casing as claimed in claim 6, characterized in that: The inner steel wire mesh and the outer steel wire mesh are both formed by overlapping one or more diamond-shaped steel plate meshes with staggered holes.

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