Cast-in-place pile pulling-out device under low clearance condition
By setting up steel anchors inside the cast-injected piles and cutting soil with high-pressure rotary spray piles, the problem of difficulty in safely and quickly pulling out the cast-injected piles under low clearance conditions is solved, and safe and fast pulling out and structural safety are achieved.
Patent Information
- Application Number
- CN202421711180.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2034-07-19
AI Technical Summary
Under low clearance conditions, it is difficult for the prior art to remove drilled piles safely and quickly without affecting the current structure.
A cast-injection pile removal device under low clearance conditions was designed. By installing steel anchors inside the current cast-injection pile, a firm anchor pull rod is formed, and the soil is cut by high-pressure rotary spray piles, reducing friction resistance, and filling the cavity with preset grouting pipes to ensure structural safety.
It has achieved safe and rapid removal of the current cast-in-place piles under low clearance conditions, reducing disturbances to the soil, and ensuring the safety of the current structure.
Smart Images
Figure CN223017624U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of cast-in-place pile extraction construction, in particular to a cast-in-place pile extraction device under low clearance conditions. Background Technique
[0002] With the continuous development of urban underground space, new underground projects often encounter obstacles such as abandoned bored cast-in-place piles left by previous engineering construction, such as temporary column piles under existing bridges, tunnels, and box culverts. When a new underground project passes through the range of these piles, it is necessary to extract and clear the bored cast-in-place piles under low clearance conditions, and ensure that the existing structure is not affected during the construction process. When extracting the pile, generally, a hoop can be used to hold the pile head to extract the pile, or the internal steel bars of the bored cast-in-place pile can be used as anchor tie rods to extract the pile. However, once the pile head concrete is damaged, the hoop will loosen and fall off; moreover, the internal steel bars of the cast-in-place pile are generally not all full-length steel bars, and it is not easy to confirm its full-length steel bars. Therefore, the internal steel bars of the bored cast-in-place pile cannot be used as anchor tie rods to extract the pile. Summary of the Invention
[0003] The technical problem to be solved by the utility model is to provide a cast-in-place pile extraction device under low clearance conditions in view of the above-mentioned prior art deficiencies.
[0004] The technical solution of the utility model to solve the above technical problem is as follows: A cast-in-place pile extraction device under low clearance conditions includes an existing cast-in-place pile, a steel section, and two hydraulic jacking mechanisms arranged under the underground structure floor slab. At least two anchor rod drill holes are arranged in the existing cast-in-place pile, steel bar anchor rods are arranged in the anchor rod drill holes, high-pressure jet grouting piles are arranged on the outer side of the existing cast-in-place pile, and two preset grouting pipes are symmetrically arranged along the length direction of the existing cast-in-place pile in the high-pressure jet grouting piles. The top of the steel bar anchor rod extends out of the underground structure floor slab, and a steel bar lifting ring is arranged at the top of the steel bar anchor rod. The steel section penetrates through the two steel bar lifting rings, and the two hydraulic jacking mechanisms are respectively arranged between the corresponding ends of the steel section and the underground structure floor slab.
[0005] The beneficial effect of the utility model is: The cast-in-place pile extraction device under low clearance conditions of the utility model forms a firm and reliable anchor tie rod for pile extraction by arranging steel bar anchor rods inside the existing cast-in-place pile, and can safely and quickly extract the existing cast-in-place pile under low clearance conditions such as under a bridge or inside an underground structure. The high-pressure water sprayed by the high-pressure jet grouting pile cuts the outer soil of the existing cast-in-place pile, reducing the frictional resistance between the pile and the soil, and can reduce the disturbance of the soil during the pile extraction process. The cavity formed under the pile can be filled while extracting the pile through the preset grouting pipe, which can ensure the safety of the existing structure.
[0006] On the basis of the above technical solution, the utility model can also be improved as follows:
[0007] Further: The anchor rod boreholes are symmetrically distributed along the central axis of the existing cast-in-place pile, and the length of the anchor rod boreholes is equal to the length of the existing cast-in-place pile.
[0008] The beneficial effect of the above further solution is that by symmetrically distributing the anchor rod boreholes along the central axis of the existing cast-in-place pile, the existing cast-in-place pile can be ensured to be more evenly stressed when pulling out the pile.
[0009] Further: The inner wall of the anchor rod borehole and the outer wall of the steel bar anchor rod are filled with cement mortar and form an integral body after curing.
[0010] The beneficial effect of the above further solution is that by filling the inner wall of the anchor rod borehole and the outer wall of the steel bar anchor rod with cement mortar, the two can form an integral body after curing. In this way, it can be used as an anchor tie rod to conveniently pull up the existing cast-in-place pile when pulling out the pile.
[0011] Further: The steel bar anchor rod is made of threaded steel, the bottom of the steel bar anchor rod is at the same elevation as the bottom of the anchor rod borehole, and the top height of the steel bar anchor rod is equal to the upper end height of the hydraulic jacking mechanism.
[0012] The beneficial effect of the above further solution is that by using threaded steel, the friction between the existing cast-in-place pile and the steel bar anchor rod can be increased. By arranging the steel bar anchor rod throughout the anchor rod borehole and connecting the upper end to the section steel, it is convenient to determine its position and also convenient for the steel bar anchor rod to pull up the existing cast-in-place pile.
[0013] Further: The high-pressure jet grouting piles surround the outside of the existing cast-in-place pile and are arranged in a biting manner, and the bottom and top of the high-pressure jet grouting piles are respectively flush with the bottom and top of the existing cast-in-place pile.
[0014] The beneficial effect of the above further solution is that by arranging the high-pressure jet grouting piles in a biting manner and arranging them throughout the existing cast-in-place pile, it is ensured that the soil around the existing cast-in-place pile is completely cut by the high-pressure jet grouting piles, reducing the frictional resistance during pile pulling.
[0015] Further: One end of the preset grouting pipe extends from the pile hole formed in the high-pressure jet grouting pile to the bottom of the existing cast-in-place pile.
[0016] The beneficial effect of the above further solution is that by extending one end of the preset grouting pipe from the pile hole formed in the high-pressure jet grouting pile to the bottom of the existing cast-in-place pile, it is convenient for the cavity left when the existing cast-in-place pile is pulled up to be filled with cement mortar sprayed by the preset grouting pipe in time, thus ensuring the safety of the existing structure.
[0017] Further: The steel bar lifting rings and the hydraulic jacking mechanisms located on both sides of the profiled steel are symmetrically arranged along the center of the profiled steel.
[0018] The beneficial effect of the above further solution is that by symmetrically arranging the steel bar lifting rings and the hydraulic jacking mechanisms on both sides of the profiled steel, the force can be made more uniform and symmetric when the existing cast-in-place pile is pulled up. Description of the Drawings
[0019] Figure 1 It is a schematic structural sectional view of a device for pulling out a cast-in-place pile under low headroom conditions according to an embodiment of the present invention;
[0020] Figure 2 It is a schematic structural plan view of a device for pulling out a cast-in-place pile under low headroom conditions according to an embodiment of the present invention.
[0021] In the drawings, the list of components represented by each reference numeral is as follows:
[0022] 1. Underground structure floor slab, 2. Existing cast-in-place pile, 3. Anchor rod hole, 4. Steel bar anchor rod, 5. High-pressure jet grouting pile, 6. Preset grouting pipe, 7. Steel bar lifting ring, 8. Profiled steel, 9. Hydraulic jacking mechanism. Detailed Embodiment
[0023] The principles and features of the present invention will be described below with reference to the drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.
[0024] As Figure 1 and Figure 2 shown, a device for pulling out a cast-in-place pile under low headroom conditions includes an existing cast-in-place pile 2, a profiled steel 8, and two hydraulic jacking mechanisms 9 arranged below the underground structure floor slab 1. At least two anchor rod holes 3 are provided in the existing cast-in-place pile 2, steel bar anchor rods 4 are provided in the anchor rod holes 3, high-pressure jet grouting piles 5 are provided on the outer side of the existing cast-in-place pile 2, two preset grouting pipes 6 are symmetrically arranged along the length direction of the existing cast-in-place pile 2 in the high-pressure jet grouting piles 5, the top of the steel bar anchor rod 4 extends out of the underground structure floor slab 1, and a steel bar lifting ring 7 is provided at the top of the steel bar anchor rod 4. The profiled steel 8 passes through the two steel bar lifting rings 7, and the two hydraulic jacking mechanisms 9 are respectively arranged between the corresponding ends of the profiled steel 8 and the underground structure floor slab 1.
[0025] The device for pulling out cast-in-place piles under low headroom conditions of the present utility model forms a firm and reliable anchor rod for pulling out piles by arranging steel bar anchor rods 4 inside the existing cast-in-place pile 2, and can safely and quickly pull out the existing cast-in-place pile 2 under low headroom conditions such as under a bridge or inside an underground structure. The high-pressure water sprayed by the high-pressure jet grouting pile 5 cuts the outer soil of the existing cast-in-place pile 2, reducing the frictional resistance between the pile and the soil, and can reduce the disturbance to the soil during the pile pulling process. Through the preset grouting pipe 6, the cavity formed under the pile can be filled while pulling out the pile, which can ensure the safety of the existing structure.
[0026] In one or more embodiments of the present utility model, the anchor rod drill holes 3 are symmetrically distributed along the central axis of the existing cast-in-place pile 2, and the length of the anchor rod drill holes 3 is equal to the length of the existing cast-in-place pile 2. By symmetrically distributing the anchor rod drill holes 3 along the central axis of the existing cast-in-place pile 2, the existing cast-in-place pile 2 can be ensured to be more evenly stressed during pile pulling. In practice, the diameter of the anchor rod drill hole is 80 mm - 100 mm.
[0027] Optionally, in one or more embodiments of the present utility model, the inner wall of the anchor rod drill hole 3 and the outer wall of the steel bar anchor rod 4 are filled with cement mortar and form an integral body after curing. By filling the inner wall of the anchor rod drill hole 3 and the outer wall of the steel bar anchor rod 4 with cement mortar, the two can form an integral body after curing. In this way, during pile pulling, it can be used as an anchor rod to conveniently pull up the existing cast-in-place pile 2.
[0028] In one or more embodiments of the present utility model, the steel bar anchor rod 4 is a deformed bar, and the bottom of the steel bar anchor rod 4 is at the same elevation as the bottom of the anchor rod drill hole 3, and the top height of the steel bar anchor rod 4 is equal to the upper end height of the hydraulic jacking mechanism 9. By using a deformed bar, the frictional force between the existing cast-in-place pile 2 and the steel bar anchor rod 4 can be increased. By arranging the steel bar anchor rod 4 throughout the anchor rod drill hole 3 and connecting the upper end to the section steel 8, it is convenient to determine its position and also convenient for the steel bar anchor rod 4 to pull up the existing cast-in-place pile 2. In practice, the steel bar anchor rod 4 is a deformed bar with a diameter of 28 mm - 32 mm.
[0029] In one or more embodiments of the present utility model, the high-pressure jet grouting piles 5 surround the outside of the existing cast-in-place pile 2 and are arranged in a bite manner, and the bottom and top of the high-pressure jet grouting piles 5 are respectively flush with the bottom and top of the existing cast-in-place pile 2. By arranging the high-pressure jet grouting piles in a bite manner and arranging them along the entire length of the existing cast-in-place pile, it is ensured that the soil around the existing cast-in-place pile is completely cut by the high-pressure jet grouting piles, reducing the frictional resistance during pile extraction. In practice, the pile diameter of the high-pressure jet grouting piles 5 is 600 mm, and the bite between two adjacent high-pressure jet grouting piles 5 is 0.1 m - 0.2 m. The pile body is closely attached to the existing cast-in-place pile 2, and both the top and bottom of the pile are flush with the existing cast-in-place pile 2.
[0030] In one or more embodiments of the present utility model, a water outlet for discharging and cutting the soil outside the existing cast-in-place pile 2 with high-pressure water is provided at the bottom of the jet grouting pipe for the construction of the high-pressure jet grouting piles 5. By providing a water outlet at the bottom of the high-pressure jet grouting piles 5, it is convenient to discharge high-pressure water through the water outlet and cut the soil outside the existing cast-in-place pile 2, thereby reducing the frictional force between the existing cast-in-place pile 2 and the soil and reducing the disturbance to the soil during pile extraction.
[0031] It should be particularly noted that in practice, in order to minimize the large-scale disturbance to the soil, the grouting pressure of the high-pressure jet grouting piles 5 is not greater than 20 MPa.
[0032] In one or more embodiments of the present utility model, one end of the preset grouting pipe 6 extends from the pile hole formed in the high-pressure jet grouting pile 5 to the bottom of the existing cast-in-place pile 2. By extending one end of the preset grouting pipe 6 from the pile hole formed in the high-pressure jet grouting pile 5 to the bottom of the existing cast-in-place pile 2, it is convenient to fill the cavity left when the existing cast-in-place pile 2 is pulled up with the cement mortar sprayed by the preset grouting pipe 6 in time, thereby ensuring the safety of the existing structure.
[0033] Optionally, in one or more embodiments of the present utility model, the steel bar lifting rings 7 and the hydraulic jacking mechanism 9 located on both sides of the steel section 9 are symmetrically arranged along the center of the steel section 9. By symmetrically arranging the steel bar lifting rings 7 and the hydraulic jacking mechanism 9 on both sides of the steel section 9, the force is more uniform and symmetric when the existing cast-in-place pile 2 is pulled up.
[0034] In the embodiment of the present utility model, the hydraulic jacking mechanism 9 adopts an existing hydraulic jack, and the one-time jacking stroke of the hydraulic jack should be determined according to the net clear height, generally not greater than 50 cm.
[0035] The construction of the device for extracting cast-in-place piles under low headroom conditions of the present utility model specifically includes the following steps:
[0036] ① Determine the exact position of the existing cast-in-place pile 2, cut the underground structure floor slab 1 to expose the pile head of the existing cast-in-place pile 2;
[0037] ② Use a drilling rig to drill a hole in the pile body of the existing cast-in-place pile 2 to the pile bottom to form an anchor rod hole 3. Ensure the verticality during drilling to prevent the anchor rod hole 3 from deviating from the pile body;
[0038] ③ Lower a steel bar anchor rod 4 into the anchor rod hole 3 and inject cement mortar for curing to form an anchor rod. A steel bar lifting ring 7 is welded to the top of the steel bar anchor rod 4;
[0039] ④ Use the high-pressure water sprayed by the high-pressure jet grouting pile 5 to cut the soil outside the existing cast-in-place pile 2;
[0040] ⑤ Pass the section steel 8 through the steel bar lifting ring 7 and install a hydraulic jacking mechanism 9 to ensure reliable connection between the hydraulic jacking mechanism 9 and the section steel 8;
[0041] ⑥ Start the hydraulic jacking mechanisms 9 on both sides simultaneously for pile pulling construction;
[0042] ⑦ After each jacking and pile pulling stroke is completed, break and clean the pulled part of the pile body, then lower the height of the steel bar lifting ring 7 and continue the next jacking and pile pulling.
[0043] ⑧ While pulling the pile, use the preset grouting pipe 6 to grout and fill the cavity formed under the existing cast-in-place pile 2 until the pile pulling is completed;
[0044] ⑨ Complete the pile pulling construction and restore the underground structure floor slab 1.
[0045] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A bored pile extraction device under low headroom conditions, characterized in that: The invention comprises an existing cast-in-place pile (2), a steel bar (8) and two hydraulic jacking mechanisms (9) arranged at the bottom of an underground structure bottom plate (1); at least two anchor rod holes (3) are arranged in the existing cast-in-place pile (2); a steel bar anchor rod (4) is arranged in the anchor rod hole (3); a high-pressure rotary jet pile (5) is arranged outside the existing cast-in-place pile (2); two preset grouting pipes (6) are symmetrically arranged in the high-pressure rotary jet pile (5) along the length direction of the existing cast-in-place pile (2); the top of the steel bar anchor rod (4) protrudes out of the underground structure bottom plate (1); a steel bar hanging ring (7) is arranged at the top of the steel bar anchor rod (4); the steel bar (8) passes through the two steel bar hanging rings (7); and the two hydraulic jacking mechanisms (9) are respectively arranged between the corresponding ends of the steel bar (8) and the underground structure bottom plate (1).
2. The device for removing bored piles under low clearance conditions according to claim 1 is characterized in that: The anchor rod drilling holes (3) are symmetrically distributed along the central axis of the existing cast-in-place pile (2), and the length of the anchor rod drilling holes (3) is equal to the length of the existing cast-in-place pile (2).
3. The device for removing bored piles under low clearance conditions according to claim 2 is characterized in that: Cement mortar is filled between the inner wall of the anchor rod drilling hole (3) and the outer wall of the steel bar anchor rod (4), and they form a whole after curing.
4. The device for removing bored piles under low clearance conditions according to claim 3 is characterized in that: The steel bar anchor rod (4) is made of threaded steel bar, and the bottom of the steel bar anchor rod (4) is equal to the bottom elevation of the anchor rod drill hole (3), and the top height of the steel bar anchor rod (4) is equal to the upper end height of the hydraulic jacking mechanism (9).
5. The device for removing cast-in-place piles under low clearance conditions according to claim 3 is characterized in that: The high-pressure jet grouting pile (5) surrounds the outer side of the existing cast-in-place pile (2) and is arranged in an interlocking manner, and the pile bottom and pile top of the high-pressure jet grouting pile (5) are respectively arranged flush with the pile bottom and pile top of the existing cast-in-place pile (2).
6. The device for removing bored piles under low clearance conditions according to claim 1, characterized in that: One end of the preset grouting pipe (6) extends from the pile hole formed in the high-pressure jet grouting pile (5) to the bottom of the existing cast-in-place pile (2).
7. The device for removing cast-in-place piles under low headroom conditions according to any one of claims 1 to 6, characterized in that: The steel bar lifting rings (7) and the hydraulic lifting mechanism (9) located on both sides of the steel section (9) are symmetrically arranged along the center of the steel section (9).