Karst cave rotary excavating cast-in-place pile construction device

Abstract

The utility model discloses a karst cave rotary excavating cast-in-place pile construction device which comprises a reinforcement cage, a waterproof pipe, a mold protection device, a first limiting ring and a second limiting ring. The mold protection device comprises a steel protection pipe, a valve pipe and a pushing mechanism. The method comprises the steps that the mold protection device enters the pile hole, the reinforcement cage enters the valve pipe, the cast-in-place pile is integrally poured, and the bottom bearing platform and the top bearing platform are poured. Overall pouring of the cast-in-place pile in the karst cave area can be achieved, the forming quality of the cast-in-place pile is fully guaranteed, the waterproof effect is improved, and the construction efficiency is improved while concrete waste is avoided.

Description

Technical Field

[0001] This utility model relates to the field of cast-in-place pile construction technology, specifically to a rotary drilling cast-in-place pile construction device for karst caves. Background Technology

[0002] my country has a vast area of ​​karst regions. With the rapid development of infrastructure projects in my country, more and more projects will encounter karst geological conditions, and karst caves will cause great trouble to the progress of the projects.

[0003] Currently, in the process of constructing engineering piles for the aforementioned geological conditions, most construction teams typically directly drill rotary pile holes, then lower the reinforcing cage and pour concrete to simultaneously fill the karst caves. However, because the internal space of karst caves is usually quite large, a large amount of concrete is used to fill them during actual construction, significantly increasing concrete usage and resulting in higher project costs.

[0004] Existing patent document CN117127614A provides some improvements to the construction process of rotary-drilled cast-in-place piles for reducing concrete diffusion in karst caves. The process includes the following steps: S1, detecting karst cave data at the construction site; S2, rotary-drilling and forming the pile hole; S3, draining the pile hole; S4, fabricating a reinforcing cage, and, referring to the karst cave data recorded in steps S1 and S2, installing an isolation net within the reinforcing cage to prevent concrete diffusion; S5, lowering the reinforcing cage to seal the isolation net within the karst cave; S6, pouring and forming the cast-in-place pile. In this application, the isolation net can seal the karst cave location during the pile casting process, reducing concrete diffusion in the karst cave area. This saves concrete usage and further reduces project costs. However, this patent document has the following drawbacks:

[0005] (1) Cast-in-place piles need to be poured in sections, which increases the risk of pile breakage, makes the concrete in the pile body prone to segregation, and will significantly reduce construction efficiency.

[0006] (2) During the rotary drilling of the pile hole, the soil around the karst cave is easily loosened. Although the literature has tied an isolation net outside the steel cage, it is difficult to guarantee that the soil at the junction of the pile hole and the karst cave will not collapse during the construction process, and there is still a great risk of concrete waste. Utility Model Content

[0007] This utility model provides a rotary drilling and grouting pile construction device for karst caves, which aims to solve the problems described in the background section (1) and (2).

[0008] To solve the above problems, the technical solution of this utility model is as follows:

[0009] A rotary drilling grouting pile construction device for karst caves includes a reinforcing cage, a waterproof pipe, and a mold protection device. The top of the reinforcing cage is connected to a first limiting ring, and the bottom is welded to a second limiting ring. A waterproof pipe is coaxially clamped between the first and second limiting rings and located on the outer periphery of the reinforcing cage. The mold protection device includes a steel protective pipe and a valve tube. The valve tube is formed by joining two or more arc-shaped plates together. The inner diameter of the joined valve tube is the same as the outer diameter of the waterproof pipe. The valve tube is located inside the steel protective pipe. The inner wall of the steel protective pipe is provided with a pushing mechanism connected to the outer wall of each arc-shaped plate. The waterproof pipe is located inside the valve tube. When the pushing mechanism pushes the valve tube into a complete pipe, the inner wall of the valve tube fits against the outer wall of the waterproof pipe.

[0010] Preferably, the first limiting ring is an inverted "convex" structure, the upper end of the waterproof pipe is engaged with the small diameter section of the inverted "convex" structure, the outer wall of the waterproof pipe is flush with the outer wall of the large diameter section of the inverted "convex" structure, and a number of connecting holes are evenly distributed around the axis on the first limiting ring, and the inner hole of the first limiting ring is used to pass through the first conduit for pouring concrete.

[0011] Preferably, the reinforcing cage includes a plurality of longitudinal bars arranged along the longitudinal direction and evenly distributed around the axis of the reinforcing cage. A plurality of annular reinforcing bars are evenly welded between the inner walls of the longitudinal bars along the height direction. The longitudinal bars are aligned with the connecting holes one by one. The top of the longitudinal bars passes through the connecting holes and is coaxially welded with an auxiliary lifting rod. The top of the outer wall of the longitudinal bars is provided with external threads and is screwed with a limiting nut for limiting the position of the first limiting ring. The auxiliary lifting rod is used to connect to the lifting equipment.

[0012] Preferably, the second limiting ring is an upright "convex" structure and coaxial with the reinforcing cage. The top of the upright "convex" structure is welded to the bottom of the longitudinal reinforcement. The lower end of the waterproof pipe is snapped into the small-diameter section of the upright "convex" structure. The outer surface of the waterproof pipe is flush with the outer surface of the large-diameter section of the upright "convex" structure.

[0013] Preferably, the waterproof pipe is a rubber pipe, PVC pipe, or PE pipe.

[0014] Preferably, the length of the steel protective pipe is the same as the height of the pile hole of the cast-in-place pile, the length of the valve tube is the same as the length of the waterproof pipe, the jacking mechanism includes one or more electrically controlled telescopic devices located at the upper and lower ends of the arc plate, one end of the electrically controlled telescopic device is hinged to the inner wall of the steel protective pipe, and the other end is hinged to the outer wall of the arc plate, the axis of the electrically controlled telescopic mechanism intersects the axis of the valve tube, and the inner wall of the arc plate is provided with an elastic buffer layer.

[0015] Preferably, it also includes a top support molded protective cylinder, the molded protective cylinder including a cylinder body with an open upper end, a through hole coaxially opened at the bottom end of the cylinder body, the inner diameter of the through hole being the same as the outer diameter of the waterproof pipe, and a number of pre-embedded steel bars being welded radially on the outer wall where the top end of the cylinder body is located.

[0016] This utility model provides a rotary drilling and grouting pile construction device for karst caves, which has the following beneficial effects:

[0017] This invention enables the integral casting of piles in karst cave areas, fully ensuring the quality of pile formation and improving waterproofing. It also avoids concrete waste and increases construction efficiency. Attached Figure Description

[0018] Figure 1 A schematic diagram of the structure of this utility model when the valve tube and the waterproof tube are separated;

[0019] Figure 2 A schematic diagram of the structure of the valve tube and the waterproof tube of this utility model when they are attached;

[0020] Figure 3 A schematic diagram of the structure of the mold protection device of this utility model when the bottom is 2.5 meters away from the bottom of the pile hole;

[0021] Figure 4 Schematic diagram of the bottom support and top support of this utility model;

[0022] Figure 5 A top view of the molded protective sleeve of this utility model;

[0023] Figure 6 A top view schematic diagram of the mold protection device and waterproof pipe of this utility model.

[0024] Figure 7 A front view structural diagram of the first limiting ring of this utility model.

[0025] Figure 8 A top view of the first limiting ring of this utility model.

[0026] Figure 9 A schematic diagram of the structure of the second limiting ring of this utility model in conjunction with the bottom of the waterproof pipe.

[0027] 1: Karst cave; 2: Pile hole; 3: Reinforcing cage; 31: Longitudinal reinforcement; 32: Auxiliary lifting rod; 4: Soil; 5: Steel protective pipe; 6: Valve tube; 61: Arc plate; 7: Waterproof pipe; 8: Jacking mechanism; 9: Second limiting ring; 10: First limiting ring; 101: Small diameter section of inverted "convex" shaped structure; 102: Connecting hole; 103: Inner hole of the first limiting ring; 11: Limiting nut; 12: Support; 13: Annular space to be poured; 14: Gap between valve plate and waterproof pipe; 15: Bottom foundation; 16: Molded protective casing; 17: Embedded reinforcement; 18: Top foundation; 19: Concrete. Detailed Implementation

[0028] The following is a detailed description of the embodiments of this utility model in a step-by-step manner. This description is only a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

[0029] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or a specific orientation structure and operation. Therefore, they should not be construed as limitations on this utility model.

[0030] In the initial embodiment, the present invention provides a rotary drilling and grouting pile construction device for karst caves, such as... Figure 1-9 As shown, the device includes a reinforcing cage 3, a waterproof pipe 7, and a mold protection device. The top of the reinforcing cage 3 is connected to a first limiting ring 10, and the bottom is welded to a second limiting ring 9. A waterproof pipe 7 is coaxially engaged between the first limiting ring 10 and the second limiting ring 9, located on the outer periphery of the reinforcing cage 3. The mold protection device includes a steel protective pipe 5 and a valve tube 6. The valve tube 6 is formed by joining two or more arc-shaped plates 61. The inner diameter of the joined valve tube 6 is the same as the outer diameter of the waterproof pipe 7. The valve tube 6 is located inside the steel protective pipe 5. The inner wall of the steel protective pipe 5 is provided with a pushing mechanism 8 connected to the outer wall of each arc-shaped plate 61. The waterproof pipe 7 is located inside the valve tube 6. Figure 6 As shown, when the pushing mechanism 8 pushes the valve tube 6 into a complete tube, the inner wall of the valve tube 6 fits against the outer wall of the waterproof tube 7.

[0031] In this embodiment, the mold protection device protects the inner wall of the pile hole on one hand, and protects the waterproof pipe by driving the valve tube to form on the other, effectively preventing the waterproof pipe from cracking during the pouring process. This assists in the integral pouring and one-time molding of the cast-in-place pile, avoiding the quality risks associated with segmented pouring. By setting up the waterproof pipe, the cast-in-place pile can have good waterproof function, enabling it to adapt to the special geological conditions of karst areas. At the same time, the waterproof pipe maintains the distance between itself and the reinforcing cage through the constraints of the first and second limiting rings, which is suitable for the precise forming of the reinforcing steel protective layer.

[0032] In a further embodiment, such as Figure 1-9 As shown, the first limiting ring 10 is an inverted "convex" structure. The upper end of the waterproof pipe 7 is engaged with the small diameter section 101 of the inverted "convex" structure. The outer wall of the waterproof pipe 7 is flush with the outer wall of the large diameter section of the inverted "convex" structure. Several connecting holes 102 are evenly distributed around the axis on the first limiting ring 10. The inner hole 103 of the first limiting ring is used to pass through the first conduit for pouring concrete.

[0033] like Figure 1-9 As shown, the steel cage 3 includes several longitudinal bars 31 arranged longitudinally and evenly distributed around the axis of the steel cage. Several annular steel bars (stirrups) are evenly welded between the inner walls of the longitudinal bars 31 along the height direction. The longitudinal bars 31 are one-to-one with the connecting holes 102. The top of the longitudinal bars 31 passes through the connecting holes 102 and is coaxially welded with an auxiliary lifting rod 32. The top of the outer wall of the longitudinal bars 31 is provided with external threads and is screwed with a limiting nut 11 for limiting the position of the first limiting ring 10. The auxiliary lifting rod 32 is used to connect the lifting equipment.

[0034] In a further embodiment, such as Figure 1-9 As shown, the second limiting ring 9 is an upright "convex" structure and coaxial with the reinforcing cage 3. The top of the upright "convex" structure is welded to the bottom end of the longitudinal reinforcement 31. The lower end of the waterproof pipe 7 is engaged with the small-diameter section of the upright "convex" structure (e.g., Figure 9 As shown in the figure, the outer surface of the waterproof pipe 7 is flush with the outer surface of the large-diameter section of the upright "convex" shaped structure.

[0035] In a further embodiment, such as Figure 1-9 As shown, the waterproof pipe 7 is a rubber pipe, PVC pipe, or PE pipe.

[0036] In a further embodiment, such as Figure 1-9As shown, the length of the steel protective pipe 5 is the same as the height of the pile hole 2 of the cast-in-place pile, the length of the valve tube 6 is the same as the length of the waterproof pipe 7, and the jacking mechanism 8 includes one or more electrically controlled telescopic devices, such as electric push rods, cylinders, and hydraulic cylinders, located at the upper and lower ends of the arc plate. One end of the electrically controlled telescopic device is hinged to the inner wall of the steel protective pipe 5, and the other end is hinged to the outer wall of the arc plate 61. The axis of the electrically controlled telescopic mechanism intersects with the axis of the valve tube 6, that is, both push in the direction of the valve tube axis to prevent deviation. The inner wall of the arc plate 61 is provided with an elastic buffer layer to tightly fit the waterproof pipe.

[0037] In a further embodiment, such as Figure 1-9 As shown, it also includes a top support 18 forming a protective sleeve 16. The forming protective sleeve 16 includes a cylindrical body with an open upper end, and a through hole coaxially opened at the bottom end of the cylindrical body, such as... Figure 5 As shown, the inner diameter of the through hole is the same as the outer diameter of the waterproof pipe 7, and several pre-embedded steel bars 17 are welded radially on the outer wall where the top of the cylinder is located.

[0038] Based on the above embodiments, this embodiment discloses the construction content of a rotary drilling and grouting pile construction device for karst caves, such as... Figure 1-9 As shown, it includes the following:

[0039] The data of the karst cave at the construction site is detected by the detection equipment. The data of the karst cave includes at least the location, height and span of karst cave 1.

[0040] Rotary drilling was carried out to form pile hole 2, with the lower end of pile hole 2 being 3 meters lower than the bottom of the karst cave 1 at the junction with the pile hole;

[0041] Drainage should be carried out in pile hole 2;

[0042] The mold protection device is hoisted into the pile hole 2 as a whole, so that the steel protective pipe 5 is positioned to be close to or in contact with the inner wall of the pile hole 2, with the bottom end of the steel protective pipe 5 abutting against the bottom of the pile hole 2.

[0043] like Figure 2 As shown, ground personnel control the electric telescopic device to move synchronously, so that the valve tube 6 forms a complete pipe; then, with the cooperation of the lifting equipment, the steel cage 3 with the waterproof pipe 7 pre-clamped is lowered with the inner wall of the pipe as the guide hole, so that the second limiting ring 9 contacts the bottom of the pile hole 2.

[0044] like Figure 2 As shown, a support 12 is erected on the ground around the pile hole 2, and an auxiliary hanging rod 32 is fixed by the support 12 to keep the steel cage 3 in its current position; the first guide pipe is inserted through the inner hole 103 of the first limiting ring to pour the cast-in-place pile as a whole. During this process, the valve tube 6 protects the outer wall of the waterproof tube 7 to ensure that it can withstand the force of the concrete during pouring.

[0045] like Figure 3 As shown, after the cast-in-place pile is formed, the electrically controlled expansion device retracts, and the valve tube 6 is decomposed into 2 to more arc-shaped plates 61. The arc-shaped plates 61 move towards the steel protective pipe 5 side due to the retraction of the electrically controlled expansion device. Then, the mold protection device is lifted upward by the lifting equipment so that the bottom of the mold protection device is 2.5 meters away from the bottom of the pile hole.

[0046] Insert a second conduit into the gap between the arc plate 61 and the waterproof pipe 7. Insert the second conduit into the annular space 13 between the bottom of the mold protection device and the bottom of the pile hole. According to the capacity of the annular space 13, inject self-compacting concrete grout. After the self-compacting grout is formed, it forms the bottom pile cap 15 of the cast-in-place pile.

[0047] Remove the support 12, lift out the mold protection device as a whole, open an annular groove on the outer periphery of the upper end of the pile hole 2, insert the molded protective sleeve 16 into the top of the pile hole, the outer wall of the molded protective sleeve 16 fits the inner wall of the pile hole 2, the through hole is fitted with the outer wall of the waterproof pipe 7, and the pre-embedded steel bar 17 is welded to the steel cage of the top support 18 in the annular groove.

[0048] Concrete 19 is poured into the molded casing 16 and the annular groove to form the top bearing platform 18, and the auxiliary hanger 32 at the top of the cast-in-place pile is cut off.

Claims

1. A rotary drilling and grouting pile construction device for karst caves, characterized in that: The system includes a steel cage, a waterproof pipe, and a mold protection device. The top of the steel cage is connected to a first limiting ring, and the bottom is welded to a second limiting ring. A waterproof pipe is coaxially connected between the first and second limiting rings and located on the outer periphery of the steel cage. The mold protection device includes a steel protective tube and a valve tube. The valve tube is formed by joining two or more arc-shaped plates. The inner diameter of the joined valve tube is the same as the outer diameter of the waterproof tube. The valve tube is located inside the steel protective tube. The inner wall of the steel protective tube is provided with a pushing mechanism that is connected to the outer wall of each arc-shaped plate. The waterproof tube is located inside the valve tube. When the pushing mechanism pushes the valve tube into a complete tube, the inner wall of the valve tube fits against the outer wall of the waterproof tube.

2. The rotary drilling and grouting pile construction device for karst caves as described in claim 1, characterized in that: The first limiting ring is an inverted "convex" structure. The upper end of the waterproof pipe is engaged with the small diameter section of the inverted "convex" structure. The outer wall of the waterproof pipe is flush with the outer wall of the large diameter section of the inverted "convex" structure. Several connecting holes are evenly distributed around the axis on the first limiting ring. The inner hole of the first limiting ring is used to pass through the first conduit for pouring concrete.

3. The rotary drilling and grouting pile construction device for karst caves as described in claim 2, characterized in that: The steel cage includes several longitudinal bars arranged along the longitudinal direction and evenly distributed around the axis of the steel cage, and several annular steel bars are evenly welded between the inner walls of the longitudinal bars along the height direction. The longitudinal ribs are aligned with the connecting holes one by one. The top of the longitudinal ribs passes through the connecting holes and is coaxially welded with an auxiliary lifting rod. The top of the outer wall of the longitudinal ribs is provided with external threads and screwed with a limiting nut for limiting the position of the first limiting ring. The auxiliary lifting rod is used to connect the lifting equipment.

4. The rotary drilling and grouting pile construction device for karst caves as described in claim 3, characterized in that: The second limiting ring is an upright "convex" shaped structure and is coaxial with the reinforcing cage. The top of the upright "convex" shaped structure is welded to the bottom of the longitudinal reinforcement. The lower end of the waterproof pipe is snapped into the small diameter section of the upright "convex" shaped structure. The outer surface of the waterproof pipe is flush with the outer surface of the large diameter section of the upright "convex" shaped structure.

5. The rotary drilling and grouting pile construction device for karst caves as described in claim 4, characterized in that: The waterproof pipe is a rubber pipe, PVC pipe, or PE pipe.

6. The rotary drilling and grouting pile construction device for karst caves as described in claim 5, characterized in that: The length of the steel protective pipe is the same as the height of the pile hole of the cast-in-place pile, the length of the valve tube is the same as the length of the waterproof pipe, and the jacking mechanism includes one or more electrically controlled telescopic devices located at the upper and lower ends of the arc plate. One end of the electrically controlled telescopic device is hinged to the inner wall of the steel protective pipe, and the other end is hinged to the outer wall of the arc-shaped plate. The axis of the electrically controlled telescopic mechanism intersects with the axis of the valve tube. The inner wall of the arc-shaped plate is provided with an elastic buffer layer.

7. The rotary drilling and grouting pile construction device for karst caves as described in claim 6, characterized in that: It also includes a top support molded protective cylinder, which includes a cylinder with an open upper end, a through hole coaxially opened at the bottom end of the cylinder, the inner diameter of the through hole being the same as the outer diameter of the waterproof pipe, and several pre-embedded steel bars welded radially on the outer wall where the top of the cylinder is located.

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