Composite PHC tubular pile structure for karst subsidence area

Abstract

The utility model discloses a composite PHC tubular pile structure for a karst subsidence area, which belongs to the technical field of tubular piles, and comprises a PHC tubular pile, a grouting pile groove and a reinforcement cage, the grouting pile groove is arranged in the karst subsidence area, the PHC tubular pile is arranged in the grouting pile groove, the reinforcement cage is placed in the middle of the inner side of the PHC tubular pile in a penetrating manner, and a wear-resistant inner pipe and a reinforcing plate are arranged between the reinforcement cage and the PHC tubular pile. The interior and the exterior of the PHC pipe pile are filled with concrete. The composite PHC tubular pile has the advantages that the cast-in-place pile and the PHC tubular pile are fused to form the composite PHC tubular pile suitable for the karst subsidence area, the characteristic of slow pile forming of the cast-in-place pile can be optimized by taking the PHC tubular pile as a main pile body, meanwhile, a cast-in-place pile steel casing can be replaced, the problem that pile forming is difficult due to grout runout and hole collapse in the karst cave penetrating area is solved, and the composite PHC tubular pile is suitable for the karst subsidence area. The construction cost is greatly saved, the problem that the pipe pile penetrates through a karst cave and is prone to being broken is solved by combining rotary digging and hole forming of the cast-in-place pile, and meanwhile the PHC pipe pile is high in strength, good in durability and long in service life.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of pipe pile, specifically, relate to a kind of composite PHC pipe pile structure for karst collapse area. BACKGROUND

[0002] Karst landform is a kind of geological phenomenon due to groundwater dissolving carbonate rock, commonly found in limestone and dolomite area. The formation of this kind of landform leads to the existence of underground cave, sinkhole and underground river channel and other special structures, further causing the risk of surface subsidence. The construction project in karst collapse area not only needs to deal with the instability of geology, but also needs to solve the potential influence of groundwater on the project.

[0003] Pile foundation as one of commonly used foundation treatment means is particularly important in karst collapse area, and pile foundation of building and structure needs to fall in stable stratum to ensure the stability of single body. The existing pile foundation is mainly divided into two kinds: cast-in-place pile and high-strength prestressed pipe pile. The first kind is reinforced concrete cast-in-place pile with steel casing. The second kind is high-strength prestressed pipe pile, and the conventional construction method is static pressure, hammering and small-diameter hole drilling.

[0004] The pipe pile structure for karst collapse area in the prior art either cannot take out the steel casing after pile forming, the cast-in-place pile is slow, the construction period is long, or is easy to cause broken pile. In order to control the broken pile rate, the vertical bearing capacity of single pile should not be too high, and the lateral performance of pipe pile is poor. For the area where karst collapse has occurred, it is necessary to select the bearing layer in relatively stable rock stratum, pass through karst cave, and fall in stable rock stratum with large buried depth, so the required pile length is also long, which undoubtedly increases the engineering cost, construction difficulty and construction period, etc. At the same time, the invention patent with publication number CN109371974A discloses a PHC pipe pile implantation construction method suitable for hard geology. First, rotary drilling machine is used to drill to complete hard rock layer, and after hole forming, high flow state fine stone concrete is poured. Before the initial setting of concrete, PHC pipe pile is concentrically implanted in concrete to the design elevation. After the setting of concrete, PHC pipe pile and the surrounding concrete are combined into a stiff composite pile, so that the prestressed pipe pile is applied to the rock-embedded pile, the advantages of high concrete strength of PHC pipe pile and large bearing capacity of bedrock are fully utilized, so as to improve the single pile bearing capacity. The pipe pile structure, the cast-in-place pile is slow, the construction period is long, and the practicality and durability need to be improved. UTILITY MODEL CONTENTS

[0005] In order to overcome the problems of the prior art, such as the slow pile forming of the post-pile steel casing, the long construction period, the easy breakage of the pile, the control of the breakage rate, the single pile vertical bearing capacity not being too high, the poor lateral performance of the pipe pile body, the poor overall durability and practicability of the pipe pile structure, etc., the utility model provides a composite PHC pipe pile structure for karst collapse area, which comprises a PHC pipe pile, a pile pouring groove and a steel reinforcement cage.

[0006] The pouring pile and the PHC pipe pile are fused to form the composite PHC pipe pile suitable for the karst collapse area.

[0007] Preferably, the inner wall of the pile pouring groove is formed with a mud protection wall.

[0008] Preferably, the steel reinforcement cage comprises an outer cage and an inner cage which are sleeved with each other, the inner cage is inserted into the outer cage, and the bottom of the outer cage is formed with a barb.

[0009] The steel reinforcement cage is placed in the pipe pile, and the whole pile core is filled with concrete, so that the pipe pile and the surrounding rock-soil body are fully combined through the steel reinforcement cage and the concrete, thereby solving the problems of the poor lateral performance of the PHC pipe pile body and the poor anti-pulling capacity of the PHC pipe pile after the pre-drilling.

[0010] Preferably, the PHC pipe pile and the pile pouring groove are formed with a concrete thickened outer wall through the concrete.

[0011] Preferably, the middle of the PHC pipe pile is provided with a filling core concrete which wraps the steel reinforcement cage.

[0012] Preferably, the outer surface of the PHC pipe pile is provided with a pressure-bearing protective sleeve.

[0013] Preferably, the inner side of the PHC pipe pile is formed with a wear-resistant inner tube, and a plurality of long strip-shaped reinforcing plates are installed on the wear-resistant inner tube.

[0014] Preferably, the bottom of the PHC pipe pile and the lower surface of the pile pouring groove are formed with a gap and are provided with hole bottom concrete.

[0015] Preferably, the outer diameter of the PHC pipe pile is smaller than the inner diameter of the pile pouring groove, and the difference is 19cm-21cm.

[0016] Preferably, the single length of the PHC pipe pile is 10-15m.

[0017] The composite PHC pipe pile has no risk of broken pile in the piling process, and the vertical bearing capacity of a single pile can be maximized, and the problem that the bearing capacity of the PHC pipe pile is not suitable for being too large and needs to be satisfied by increasing the number of piles.

[0018] Beneficial effects:

[0019] The beneficial effects of the technical scheme of the utility model are as follows:

[0020] (1) The cast-in-place pile and the PHC pipe pile are fused to form the composite PHC pipe pile suitable for the karst collapse area, the PHC pipe pile can optimize the piling characteristics of the cast-in-place pile as the main pile body, and the PHC pipe pile can also replace the cast-in-place pile steel casing to solve the problems of slurry running and hole collapse in the process of penetrating the karst cave area, thereby greatly saving the cost, and the pipe pile penetrating the karst cave is easy to break, and the problem is solved by combining the rotary excavation hole of the cast-in-place pile, the PHC pipe pile has high strength and good durability, and has good service life and application range.

[0021] (2) The steel reinforcement cage is placed in the pipe pile, and the concrete is poured in the whole pile core, the pipe pile and the surrounding rock-soil body are fully combined through the steel reinforcement cage and the concrete, and the problems of poor lateral performance of the PHC pipe pile and poor anti-pulling ability of the PHC pipe pile after pre-drilling are solved.

[0022] (3) The composite PHC pipe pile has no risk of broken pile in the piling process, and the vertical bearing capacity of a single pile can be maximized, and the problem that the bearing capacity of the PHC pipe pile is not suitable for being too large and needs to be satisfied by increasing the number of piles. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be briefly introduced the drawings needed to be used in the embodiments, it should be understood, the following drawings only show some embodiments of the utility model, therefore should not be regarded as the limitation to the scope, for the ordinary skilled person in the art, under the premise of not paying the creative labor, still can obtain other related drawings according to these drawings.

[0024] Fig. 1 It is the overall structure schematic diagram of the composite PHC pipe pile structure for the karst collapse area of the utility model;

[0025] Fig. 2 It is the top view structure schematic diagram of the PHC pipe pile on the composite PHC pipe pile structure for the karst collapse area of the utility model;

[0026] Fig. 3It is the structural diagram of the steel reinforcement cage on the composite PHC pipe pile structure for karst collapse area.

[0027] In the figure: 1, PHC pipe pile; 2, pile slot; 3, mud protection wall; 4, concrete thickened outer wall; 5, steel reinforcement cage; 6, pressure bearing protective sleeve; 7, wear-resistant inner tube; 8, reinforcing plate; 9, outer cage; 10, inner cage; 11, core concrete; 12, barb. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the utility model.

[0029] The embodiments of the utility model fuse the cast-in-place pile and the PHC pipe pile to form a composite PHC pipe pile suitable for karst collapse area. The PHC pipe pile can optimize the slow pile-forming characteristics of the cast-in-place pile as the main pile body, and can also replace the cast-in-place pile steel casing to solve the problems of slurry running and hole collapse during the pipe pile passing through the karst cave area, greatly saving the cost. In combination with the rotary excavation of the cast-in-place pile, the problem of easy pipe pile breaking during the pipe pile passing through the karst cave is solved. The specific embodiments are as follows:

[0030] As shown in Figs. 1 to 3 A composite PHC pipe pile structure for karst collapse area includes a PHC pipe pile 1, a pile slot 2 and a steel reinforcement cage 5. The pile slot 2 is arranged in the karst collapse area, and the PHC pipe pile 1 is arranged in the pile slot 2. The steel reinforcement cage 5 is placed in the middle of the inner side of the PHC pipe pile 1. The wear-resistant inner tube 7 and the reinforcing plate 8 are arranged between the steel reinforcement cage 5 and the PHC pipe pile 1. The inside and outside of the PHC pipe pile 1 are filled with concrete. The cast-in-place pile and the PHC pipe pile are fused to form a composite PHC pipe pile structure suitable for karst collapse area. The PHC pipe pile 1 can optimize the slow pile-forming characteristics of the cast-in-place pile as the main pile body, and can also replace the cast-in-place pile steel casing to solve the problems of slurry running and hole collapse during the pipe pile passing through the karst cave area, greatly saving the cost. In combination with the rotary excavation of the cast-in-place pile, the problem of easy pipe pile breaking during the pipe pile passing through the karst cave is solved.

[0031] The inner wall of the pile slot 2 is formed with a mud protection wall 3. By arranging the mud protection wall 3 on the inner wall of the pile slot 2 (into the area other than the stable bedrock), a relatively stable pile slot 2 (i.e. a pre-drilled hole) can be formed, which can reduce the risk of pipe pile breaking when passing through a cave. The material of the mud protection wall 3 is composed of water, clay (bentonite) and additives. The pre-drilling hole forming method of the mud protection wall is the same as the construction technology of the mud protection wall rotary drilling hole cast-in-place pile.

[0032] The steel reinforcement cage 5 comprises an outer cage 9 and an inner cage 10 which are sleeved with each other, the inner cage 10 is arranged in the outer cage 9, and the bottom of the outer cage 9 is formed with a barb 12. The steel reinforcement cage 5 is placed in the PHC pipe pile 1, and the whole pile core is filled with concrete. The PHC pipe pile 1 and the surrounding rock-soil body are fully combined through the steel reinforcement cage 5 and the concrete, which solves the problems of poor lateral performance of the PHC pipe pile 1 and poor uplift resistance of the PHC pipe pile 1 after pre-drilling. The barb 12 is arranged at the bottom of the steel reinforcement cage 5, which further enhances the connection between the pile bottom and the bedrock and the anti-pulling effect of the pile foundation.

[0033] The PHC pipe pile 1 and the pile slot 2 are formed with a concrete thickened outer wall 4 through concrete. Through the concrete thickened outer wall 4, the integrity of the pipe pile after splicing can be enhanced, the adhesion with the mud protection wall 3 can be enhanced, and the overall lateral performance and uplift resistance of the composite PHC pipe pile 1 can be further increased.

[0034] The middle of the PHC pipe pile 1 is provided with a core filling concrete 11 which wraps the steel reinforcement cage 5. Through the core filling concrete 11, the self-weight of the pipe pile can be increased to avoid the pipe pile from floating up.

[0035] The outer surface of the PHC pipe pile 1 is provided with a pressure bearing protective sleeve 6. Through the pressure bearing protective sleeve 6, the overall strength and pressure bearing capacity of the PHC pipe pile 1 can be enhanced, so that it is not easy to be damaged and broken.

[0036] The inner side of the PHC pipe pile 1 is formed with a wear-resistant inner tube 7, and a plurality of long strip-shaped reinforcing plates 8 are installed on the wear-resistant inner tube 7. Through the wear-resistant inner tube 7, the wear resistance of the inside of the PHC pipe pile 1 can be enhanced, and the service life can be improved. Through the reinforcing plates 8, the strength of the PHC pipe pile 1 and the stability of the whole pipe pile can be further improved.

[0037] The bottom of the PHC pipe pile 1 and the lower surface of the pile slot 2 are formed with a gap and provided with a hole bottom concrete. Through the hole bottom concrete, the pipe pile can be buffered when it is lowered to the bedrock, and it is not easy to break, and the connection between the pipe pile and the bedrock is increased

[0038] The outer diameter of the PHC pipe pile 1 is smaller than the inner diameter of the pile slot 2, and the difference is 19cm-21cm. In the process of forming the composite PHC pipe pile, there is basically no risk of pipe pile breaking, which can maximize the vertical bearing capacity of a single pile, and solve the problem that the bearing capacity of the PHC pipe pile is not suitable to be too large, and the bearing capacity needs to be increased by increasing the number of piles.

[0039] The single-section length of the PHC pipe pile 1 is 10-15m.

[0040] In the process of setting the composite PHC pipe pile, first, pre-drilling is performed and a slurry lining is formed, and the karst collapse area and the surrounding rock-soil body can be penetrated in sequence, and the stable bedrock is drilled into, then the hole bottom concrete is poured at the hole bottom, and the outer cage of the reinforcement cage is lowered in time, the bottom of the outer cage is provided with a barb, which can further enhance the connection between the pile bottom and the bedrock and the anti-pulling effect of the pile foundation, the PHC pipe pile is lowered before the hole bottom concrete is initially cured, the subsequent pipe pile is connected to the ground, and the inner cage of the reinforcement cage is continuously lowered in the PHC pipe pile until the top of the pipe pile, then the core concrete is poured into the PHC pipe pile core in full length, the core concrete is formed, finally, the gap between the pre-drilling pile pouring groove and the PHC pipe pile is filled with concrete to fill, the pipe pile concrete thickened outer wall is formed, and the composite PHC pipe pile structure is realized.

[0041] Working principle: The bored pile and the PHC pipe pile are fused to form a composite PHC pipe pile suitable for the karst collapse area, the PHC pipe pile can optimize the characteristics of the bored pile pile forming as the main pile body, and can also replace the bored pile steel casing to solve the problems of slurry running and hole collapse caused by the difficulty of pile forming in the karst collapse area, greatly saving the cost, and combining the rotary drilling of the bored pile to solve the problem of easy pipe pile breaking in the karst collapse area, the reinforcement cage is placed in the pipe pile, and the concrete is poured into the full pile core, the pipe pile and the surrounding rock-soil body are fully combined through the reinforcement cage and the concrete, the problems of poor lateral performance of the PHC pipe pile and poor anti-pulling ability of the PHC pipe pile after pre-drilling are solved, the composite PHC pipe pile has basically no risk of pile breaking during pile forming, the vertical bearing capacity of a single pile can be maximized, and the problem that the bearing capacity of the PHC pipe pile is not suitable for being too large and needs to be increased by increasing the number of piles to meet the bearing capacity is solved.

[0042] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A composite PHC pipe pile structure for karst collapse area, characterized in that, The utility model provides a kind of PHC pipe pile (1), fills pile slot (2) and reinforcement cage (5), the filling pile slot (2) is arranged in karst collapse area, the filling pile slot (2) is provided with PHC pipe pile (1), the middle part of the inside of the PHC pipe pile (1) is inserted and placed with reinforcement cage (5), and the reinforcement cage (5) is provided with wear-resistant inner tube (7) and reinforcing plate (8) between the PHC pipe pile (1), and the inside and outside of the PHC pipe pile (1) are filled with concrete respectively.

2. The composite PHC pipe pile structure for karst collapse area according to claim 1, characterized in that, The inner wall of the filling pile slot (2) is formed with slurry protection wall (3).

3. The composite PHC pipe pile structure for karst collapse area according to claim 1, characterized in that, The reinforcement cage (5) includes outer cage (9) and inner cage (10) that are mutually sleeved, the inner cage (10) is inserted and arranged in the outer cage (9), and the bottom of the outer cage (9) is formed with barb (12).

4. The composite PHC pipe pile structure for karst collapse area according to claim 1, wherein, The PHC pipe pile (1) and the filling pile slot (2) are formed with concrete thickened outer wall (4) by concrete.

5. The composite PHC pipe pile structure for karst collapse area as claimed in claim 1, wherein, The middle of the PHC pipe pile (1) is provided with filling core concrete (11) that wraps reinforcement cage (5).

6. The composite PHC pipe pile structure for karst collapse area as claimed in claim 1, wherein, The outer surface of the PHC pipe pile (1) is provided with pressure-bearing protective sleeve (6).

7. The composite PHC pile structure for karst collapse area as claimed in claim 1, wherein, The inner side of the PHC pipe pile (1) is formed with wear-resistant inner tube (7), and a plurality of long reinforcing plates (8) are installed on the wear-resistant inner tube (7).

8. The composite PHC pile structure for karst collapse area as claimed in claim 1, wherein, The bottom of the PHC pipe pile (1) and the lower surface of the filling pile slot (2) form a gap and are provided with hole bottom concrete.

9. The composite PHC pile structure for karst collapse area as claimed in claim 1, wherein, The outer diameter of the PHC pipe pile (1) is smaller than the inner diameter of the filling pile slot (2), and the difference is 19cm-21cm.

10. The composite PHC pipe pile structure for karst collapse area according to claim 8, characterized in that, The single-section length of the PHC pipe pile (1) is 10-15m.

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