Asbestosed wire gauze composite cast-in-place pile for karst cave groundwater environment and construction method

Abstract

The invention relates to the technical field of cast-in-place pile construction, in particular to an asbestosed wire gauze composite cast-in-place pile used for the karst cave underground water environment and a construction method of the asbestosed wire gauze composite cast-in-place pile used for the karst cave underground water environment. The interior of the upper steel casing and the interior of the fixed reinforcement cage are both used for placing a common reinforcement cage and pouring concrete; the end, facing the fixed reinforcement cage, of the upper steel casing is divided into a plurality of steel sheets through a plurality of upper steel casing cracks. The fixed reinforcement cage comprises an inner fixed reinforcement cage, the inner fixed reinforcement cage is sleeved with an outer fixed reinforcement cage, and the opposite side walls of the outer fixed reinforcement cage and the inner fixed reinforcement cage are coated with asbestosed wire gauzes; and the steel sheets are detachably connected with the external fixed reinforcement cage through connecting pieces. The opposite side walls of the outer fixed reinforcement cage and the inner fixed reinforcement cage are coated with the asbestosed wire gauze, so that fine particles can be effectively prevented from losing, and segregation is reduced; and the problems of deviation caused by hydrodynamic force and concrete forming are effectively solved.

Description

TECHNICAL FIELD

[0001] The application relates to a cast-in-place pile construction technology field, in particular to an asbestos net composite cast-in-place pile for a karst cave underground water environment and a construction method. BACKGROUND

[0002] Due to frequent development of underground karst caves, broken rock mass, crisscross fissures and strong underground water activity, when pile foundation construction is carried out in a karst cave development area, problems such as pile hole collapse, mud loss, concrete overfilling and insufficient bearing capacity often occur, which seriously threaten the safety of the structure and the construction efficiency.

[0003] Among the common treatment measures for karst strata at present, when the casing is followed, deep hole construction is difficult, and the problem of long-term water erosion around the pile cannot be solved. In the multilayer karst cave, concrete flow or loss is easy to occur, the integrity of the pile body is difficult to guarantee, and there are problems such as difficult control of grouting range, high cost and great environmental impact.

[0004] Therefore, an asbestos net composite cast-in-place pile for a karst cave underground water environment and a construction method are needed, which can effectively prevent fine particle loss and reduce segregation by forming a "filter layer-barrier" dual function through the asbestos net. Compared with the permeability of the traditional casing, the deviation problem caused by water power is reduced. During the pouring process, the "skeleton-matrix" synergistic effect can be effectively formed to improve the compactness and dispersion resistance of the concrete around the pile. At the same time, by separating the fixed steel reinforcement cage from the upper steel casing, the integrity and structure of the cast-in-place pile can be improved, and the formation of the internal cast-in-place pile can be effectively guaranteed. SUMMARY

[0005] The purpose of the present application is to provide an asbestos net composite cast-in-place pile for a karst cave underground water environment and a construction method to solve the problems existing in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides the following scheme: an asbestos net composite cast-in-place pile for a karst cave underground water environment, comprising an upper steel casing, the bottom of the upper steel casing is provided with a fixed steel reinforcement cage, the inside of the upper steel casing and the inside of the fixed steel reinforcement cage are used for placing ordinary steel reinforcement cages and pouring concrete; one end of the upper steel casing towards the fixed steel reinforcement cage is divided into a plurality of steel sheets through a plurality of upper steel casing cracks; the fixed steel reinforcement cage comprises an inner fixed steel reinforcement cage, an outer fixed steel reinforcement cage is sleeved on the inner fixed steel reinforcement cage, and asbestos nets are coated on the side walls opposite to the inner fixed steel reinforcement cage and the outer fixed steel reinforcement cage; the steel sheet is detachably connected with the outer fixed steel reinforcement cage through a connecting piece.

[0007] Preferably, a plurality of upper steel casing cracks are evenly spaced.

[0008] Preferably, the connecting piece comprises a buckle fixedly connected to the lower part of the inner wall of the steel sheet, and the buckle is detachably connected with a clamping groove formed in the upper part of the outer wall of the outer fixed reinforcement cage.

[0009] Preferably, the cross section of the buckle is in the shape of an inverted triangle.

[0010] Preferably, a plurality of buckles are arranged in a vertical direction, and the buckles are arranged in one-to-one correspondence with the clamping grooves.

[0011] Preferably, the buckle is fixedly connected with a first traction rope, and the end of the first traction rope away from the buckle penetrates the outer fixed reinforcement cage.

[0012] Preferably, the clamping groove is fixedly connected with a second traction rope, and the end of the second traction rope away from the clamping groove penetrates the upper steel casing.

[0013] Preferably, the top of the outer fixed reinforcement cage is higher than the top of the inner fixed reinforcement cage.

[0014] Preferably, the top of the inner wall of the inner fixed reinforcement cage is provided with a guide inlet, and the end of the guide inlet with a large opening faces the upper steel casing.

[0015] A construction method of an asbestos net composite cast-in-place pile for a karst underground water environment, comprising the following steps: S1. clearing the site, burying the upper steel casing after determining the construction position; S2. lowering the fixed reinforcement cage and connecting the outer fixed reinforcement cage and the upper steel casing with each other through the connecting piece; S3. lowering the ordinary reinforcement cage, positioning, and then pouring the concrete; S4. after the pouring of the concrete is completed, disconnecting the outer fixed reinforcement cage and the upper steel casing through the connecting piece, and pulling out the upper steel casing.

[0016] The present application discloses the following technical effects: The present application coats asbestos nets on the opposite side walls of the outer fixed reinforcement cage and the inner fixed reinforcement cage, forms a "filter layer-barrier" dual function through the asbestos nets, can effectively prevent fine particles from flowing away and reduce segregation, has stronger permeability than the traditional casing, effectively reduces the deviation problem caused by water power, can effectively form a "skeleton-matrix" synergistic effect during pouring, improves the compactness and anti-dispersion capacity of the concrete around the pile, and through the disconnection of the fixed reinforcement cage and the upper steel casing, the integrality and structure of the cast-in-place pile can be improved, and the formation of the internal cast-in-place pile can be effectively ensured. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below only illustrate some of the embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative effort based on these drawings belong to the protection scope of the present application.

[0018] Figure 1 is a whole schematic view of the present application; Figure 2 is a schematic view of the connection between the upper casing and the fixed reinforcement cage of the present application; Figure 3 is a schematic view of the disconnection between the upper casing and the fixed reinforcement cage of the present application; Figure 4 is a schematic view of the local unfolding of the asbestos net of the present application; Figure 5 is a schematic view of the installation position of the asbestos net of the present application; Figure 6 is a whole schematic view of the upper casing of the present application; Figure 7 is a top view schematic view of the upper casing of the present application; Figure 8 is a schematic view of the structure of the fixed reinforcement cage of the present application; wherein 1, upper steel casing; 101, fissure of the upper steel casing; 2, buckle; 3, first traction rope; 4, fixed reinforcement cage; 401, outer fixed reinforcement cage; 402, inner fixed reinforcement cage; 5, clamping groove; 6, guide inlet; 7, asbestos net; 8, ordinary reinforcement cage; 9, concrete; 10, second traction rope. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0021] Reference Figures 1 to 8The application provides a kind of asbestos net composite bored pile for karst underground water environment, including upper steel casing 1, the bottom of upper steel casing 1 is provided with fixed reinforcement cage 4, the inside of upper steel casing 1 and fixed reinforcement cage 4 is used to place ordinary reinforcement cage 8 and pour concrete 9;Upper steel casing 1 is separated into multiple steel sheets by multiple upper steel casing fissures 101 at one end of fixed reinforcement cage 4;Fixed reinforcement cage 4 includes inner fixed reinforcement cage 402, outer fixed reinforcement cage 401 is arranged on inner fixed reinforcement cage 402, and asbestos net 7 is coated on the side wall opposite to outer fixed reinforcement cage 401 and inner fixed reinforcement cage 402;Steel sheet is detachably connected with outer fixed reinforcement cage 401 by connecting piece.

[0022] The grid specification of fixed reinforcement cage 4 is greater than that of ordinary reinforcement cage 8.

[0023] Fixed reinforcement cage 4 plays a role of fixing and casing, and provides a relatively suitable environment for the molding of concrete 9.

[0024] Further, the net spacing between the longitudinal main reinforcement of fixed reinforcement cage is greater than that between the longitudinal main reinforcement of ordinary reinforcement cage, and the stirrup is the same.

[0025] Because the size of aggregate commonly used in bored pile is 5-20mm or 5-25mm, the grid size of asbestos net 7 adopts 10*10mm specification, and most of the aggregate can be intercepted by asbestos net 7 and not taken away by water flow.

[0026] In the application, asbestos net 7 is coated on the side wall opposite to outer fixed reinforcement cage 401 and inner fixed reinforcement cage 402, and forms a double function of “filter layer-barrier”, which can effectively prevent the loss of fine particles and reduce segregation; compared with the permeability of traditional casing, the application effectively reduces the deviation problem caused by water power; and in the pouring process, the application can effectively form a “skeleton-matrix” synergistic effect to improve the compactness and dispersion resistance of the concrete around the pile; at the same time, the separation of fixed reinforcement cage 4 and upper steel casing 1 can not only improve the integrity and structure of the bored pile, but also effectively ensure the molding of the internal bored pile Further optimization scheme, multiple upper steel casing fissures 101 are evenly opened. Multiple steel sheets with the same specification are formed. The upper steel casing 1 is contracted in diameter at the lower part through the upper steel casing fissure 101, which facilitates the connection and separation of fixed reinforcement cage 4 and upper steel casing 1.

[0027] Further optimization scheme, the connecting piece includes buckle 2, the buckle 2 is fixedly connected to the lower part of the inner wall of the steel sheet, and the buckle 2 is detachably connected with the clamping groove 5, which is opened in the upper part of the outer wall of outer fixed reinforcement cage 401.

[0028] The buckles 2 are connected with the clamping grooves 5, which facilitates the connection and disconnection of the outer fixed reinforcement cage 401 and the upper steel casing 1.

[0029] For example, the upper steel casing 1 has four upper steel casing cracks 101, which are used to facilitate the contraction of the lower diameter of the upper steel casing 1 and the connection and disconnection of the fixed reinforcement cage 4 and the upper steel casing 1. The four upper steel casing cracks 101 divide the lower part into four steel sheets, and each steel sheet has a buckle 2.

[0030] Further optimization, the cross section of the buckle 2 is inverted triangular. The buckle 2 can be stably clamped in the clamping groove 5.

[0031] The inner diameter of the innermost side of the buckle 2 of the upper steel casing 1 is slightly smaller than the inner diameter of the outer fixed reinforcement cage 401 of the fixed reinforcement cage 4, which is used to immediately block the clamping groove 5 when passing through the buckle 2.

[0032] Further optimization, the buckle 2 is provided with a plurality of buckles 2 arranged in multiple rows, and the buckle 2 is matched with the clamping groove 5 and is arranged one by one. Through the one-to-one arrangement of the plurality of buckles 2 and the plurality of clamping grooves 5, the stability of the connection between the outer fixed reinforcement cage 401 and the upper steel casing 1 can be effectively improved.

[0033] Further optimization, the buckle 2 is fixedly connected with the first traction rope 3, and the end of the first traction rope 3 away from the buckle 2 penetrates the outer fixed reinforcement cage 401.

[0034] Further optimization, the clamping groove 5 is fixedly connected with the second traction rope 10, and the end of the second traction rope 10 away from the clamping groove 5 penetrates the upper steel casing 1.

[0035] The first traction rope 3 drives the steel sheet to deform, and the second traction rope 10 pulls the fixed reinforcement cage 4 to move, which facilitates the connection and disconnection of the fixed reinforcement cage 4 and the upper steel casing 1.

[0036] Further optimization, the top height of the outer fixed reinforcement cage 401 is greater than the top height of the inner fixed reinforcement cage 402. Not only is it convenient for the connection and disconnection of the buckle 2 and the clamping groove 5, but also it is convenient for pouring the outer fixed reinforcement cage 401 and the inner fixed reinforcement cage 402, i.e. the female concrete 9.

[0037] Further optimization, the top of the inner wall of the inner fixed reinforcement cage 402 is provided with a guide inlet 6, and the end of the guide inlet 6 with a large opening faces the upper steel casing 1. The guide inlet 6 guides the pouring of the concrete 9.

[0038] The upper steel casing 1 and the fixed reinforcement cage 4 both have a certain deformation recovery ability. Whether the upper steel casing 1 is expanded when the ordinary reinforcement cage 8 is lowered or the upper part of the fixed reinforcement cage is induced to shrink by the second traction rope 10, when the external force is removed, they can all recover to the initial shape.

[0039] A construction method of an asbestos net composite bored pile for a karst underground water environment, comprising the following steps: S1. After clearing the site and determining the construction position, drilling and hole forming are performed by a drilling machine; then, the embedding of the upper steel casing 1 is performed; during the placement of the upper steel casing 1, the position of the bottommost buckle 2 needs to be extended above the underground water of the karst cave.

[0040] S2. The fixed reinforcement cage 4 is lowered, and the outer fixed reinforcement cage 401 is connected with the upper steel casing 1 through the connecting piece; the buckle 2 can be inserted into the clamping groove 5 by tightening or loosening the first traction rope 3 and the second traction rope 10, so that the clamping groove 5 of the outer fixed reinforcement cage 401 is connected and locked with the buckle 2 of the upper steel casing 1.

[0041] When the buckle 2 blocks the fixed reinforcement cage 4 during the lowering process, causing the pile to be unable to sink, the first traction rope 3 can be appropriately pulled to expand the diameter of the lower part of the upper steel casing 1, so that the fixed reinforcement cage 4 is smoothly placed. After the fixed reinforcement cage 4 is placed, the ordinary reinforcement cage 8 is lowered.

[0042] S3. After the ordinary reinforcement cage 8 is lowered and positioned, the concrete 9 is poured; after the ordinary reinforcement cage 8 is placed, the concrete 9 is poured into the guide inlet 6 of the inner fixed reinforcement cage 402, and when the concrete 9 overflows from the guide inlet 6, the concrete 9 is poured from the ordinary reinforcement cage 8.

[0043] When the concrete 9 overflows from the guide inlet 6, it can be judged that the concrete 9 in the space region composed of the outer fixed reinforcement cage 401 and the inner fixed reinforcement cage 402 is poured, at which time the pouring route is switched, and the concrete 9 is continuously poured from the ordinary reinforcement cage 8 until the entire pouring pile is poured.

[0044] S4. After the concrete 9 is poured, the outer fixed reinforcement cage 401 is disconnected with the upper steel casing 1 through the connecting piece, that is, the diameter of the upper part of the fixed reinforcement cage 4 is reduced by tightening the second traction rope 10, and the buckle 2 is disconnected with the clamping groove 5; the upper steel casing 1 is pulled out. Finally, the pile head is treated and quality detection is performed.

[0045] Compared with the conventional casing, the permeability of the present application is stronger, the asbestos net 7 attached to the reinforcement cage can pass through the water flow, reduce the deviation problem caused by water power, and can intercept general coarse aggregate, reduce the loss of concrete 9 in the concrete 9 forming process, and reduce the influence on the environment.

[0046] Through the detachable connection of the fixed reinforcement cage 4 and the upper steel casing 1, the present application can effectively guarantee the internal pouring pile forming, guarantee the integrity of the pouring pile, and improve the strength of the pile body.

[0047] In the description of the present application, it needs to be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0048] The above-described embodiments are only to describe the preferred modes of the present application, and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. An asbestos mesh composite cast-in-place pile for use in karst cave groundwater environments, characterized in that: It includes an upper steel casing (1), and a fixed steel cage (4) is provided at the bottom of the upper steel casing (1). The interior of the upper steel casing (1) and the interior of the fixed steel cage (4) are used to place ordinary steel cages (8) and pour concrete (9). The upper steel casing (1) is divided into multiple steel plates at one end facing the fixed steel cage (4) by multiple upper steel casing cracks (101); The fixed steel cage (4) includes an inner fixed steel cage (402), and an outer fixed steel cage (401) is fitted on the inner fixed steel cage (402). The outer fixed steel cage (401) and the inner fixed steel cage (402) are both covered with asbestos mesh (7) on the side wall opposite to the inner fixed steel cage (402). The steel sheet is detachably connected to the external fixed steel cage (401) via a connector.

2. The asbestos mesh composite cast-in-place pile for karst cave groundwater environments according to claim 1, characterized in that: Multiple upper steel casing cracks (101) are opened at equal intervals.

3. The asbestos mesh composite cast-in-place pile for karst cave groundwater environments according to claim 1, characterized in that: The connector includes a buckle (2), which is fixedly connected to the lower part of the inner wall of the steel sheet. The buckle (2) is detachably connected to a slot (5), which is opened on the upper part of the outer wall of the outer fixed steel cage (401).

4. The asbestos mesh composite cast-in-place pile for karst cave groundwater environments according to claim 3, characterized in that: The cross-section of the buckle (2) is an inverted triangle.

5. The asbestos mesh composite cast-in-place pile for karst cave groundwater environments according to claim 3, characterized in that: Multiple buckles (2) are provided, and the multiple buckles (2) are arranged vertically. The buckles (2) are adapted to the card slots (5) and are set in a one-to-one correspondence.

6. The asbestos mesh composite cast-in-place pile for karst cave groundwater environments according to claim 3, characterized in that: The buckle (2) is fixedly connected to a first traction rope (3), and the end of the first traction rope (3) away from the buckle (2) passes through the outer fixed steel cage (401).

7. The asbestos mesh composite cast-in-place pile for karst cave groundwater environments according to claim 3, characterized in that: The slot (5) is fixedly connected to a second traction rope (10), and one end of the second traction rope (10) away from the slot (5) passes through the upper steel casing (1).

8. The asbestos mesh composite cast-in-place pile for karst cave groundwater environments according to claim 1, characterized in that: The top height of the external fixed steel cage (401) is greater than the top height of the internal fixed steel cage (402).

9. The asbestos mesh composite cast-in-place pile for karst cave groundwater environments according to claim 1, characterized in that: The top of the inner wall of the inner fixed steel cage (402) is provided with an inlet (6), and the larger end of the inlet (6) faces the upper steel casing (1).

10. A construction method for asbestos mesh composite cast-in-place piles for karst cave groundwater environments, based on the asbestos mesh composite cast-in-place piles for karst cave groundwater environments as described in any one of claims 1-9, characterized in that: Includes the following steps: S1. After cleaning the site and determining the construction location, the upper steel casing (1) is installed; S2. Lower the fixed steel cage (4) and connect the outer fixed steel cage (401) to the upper steel casing (1) through the connector; S3. After lowering and positioning the ordinary steel cage (8), pour the concrete (9). S4. After the concrete (9) is poured, the external fixed steel cage (401) is separated from the upper steel casing (1) by the connector, and the upper steel casing (1) is pulled out.

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