Composite pipe pile with drainage consolidation function
By adopting a composite pipe pile structure in soft soil areas, combined with guide rings, sand piles and drainage pipes, the problem of difficulty in achieving drainage consolidation in deep soft soil during the pre-pressure period is solved, and effective drainage consolidation and settlement control is achieved.
Patent Information
- Application Number
- CN202411743746.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-30
- Publication Date
- 2025-02-18
AI Technical Summary
In soft soil areas, it is difficult for the existing technology to effectively achieve drainage consolidation of deep soft soil during the pre-pressure period, resulting in the necessity of designing pre-pressure period being questioned, especially when the length of the pipe pile is not enough to cover all soft soil layers. .
A composite pipe pile structure is adopted, including pipe pile body, guide ring, sand pile and drain pipe. The guide ring and sand pile are used in conjunction to promote the drainage and consolidation of deep soft soil; the drainage pipe is connected through sand piles and pile caps to achieve drainage of the foundation.
Without increasing the length of the pipe pile, composite pipe piles can effectively promote the drainage and consolidation of deep soft soil, reduce post-work settlement, and improve the settlement control effect.
Smart Images
Figure CN119465913A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of composite foundation treatment in soft soil areas, and in particular to a composite pipe pile with drainage and consolidation functions. Background Art
[0002] At present, high-grade highways built in soft soil areas will have a period of static pressure from the completion of roadbed filling to the beginning of road paving, which can generally be up to 6 months. For sections of roads that have implemented pipe pile composite foundations, the soil layer at the depth of the pipe piles cannot be compressed during the preloading period, and the soft soil deeper below the pipe piles is difficult to achieve the expected drainage and consolidation effect due to the lack of drainage channels, resulting in doubts about the necessity of the design preloading period. Therefore, under the conditions of deep soft soil, especially when the length of the pipe piles cannot cover all the soft soil layers, whether a smooth drainage and consolidation channel can be retained for the deep soft soil below the pile end, or even whether vacuuming can be used to promote drainage, is the key to improving the preloading effect and reducing the post-construction settlement of the roadbed. Therefore, there is an urgent need for a method that can combine sand well preloading and pipe pile composite foundation technology to make full use of the idle period of roadbed loading and realize preloading and consolidation of deep soft soil. Summary of the invention
[0003] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and to provide a method that can combine sand well preloading and pipe pile composite foundation technology, fully utilize the idle period of roadbed loading, and achieve preloading and consolidation of deep soft soil.
[0004] To achieve the above object, the present invention is implemented through the following technical solutions:
[0005] A composite pipe pile with drainage and consolidation functions comprises a pipe pile body, a guide ring is arranged at the pile end at the bottom of the pipe pile body, a pile cap is fixedly arranged at the pile top of the pipe pile body, and a drainage pipe is passed through the pile cap and the pipe pile body; the lower part of the guide ring extends downward in a cone shape to form a ring knife-shaped tip; a sand pile extending downward from the inside of the pile end is arranged at the pile end; the lower end of the drainage pipe is inserted into the sand pile and is evenly provided with perforations, the lower end of the drainage pipe is wrapped with geotextile, and the upper end of the drainage pipe passes through the pile cap.
[0006] Furthermore, the upper portion of the guide ring extends into the pile end and is in close contact with the inner wall of the pile end, and the thickness of the top portion of the guide ring extending into the pile end gradually decreases.
[0007] Furthermore, the pile cap is cast-in-place reinforced concrete, a steel bar structure is arranged inside the pile cap, the steel bar extends downward into the pile body of the pipe pile and is welded with a circular steel plate.
[0008] Furthermore, the top of the sand pile is not less than 0.5m higher than the pile end.
[0009] Furthermore, an elbow and a threaded interface are provided at the upper end of the drainage pipe, 10 cm above the lowest point of the pile cap, and a protective cover covering the elbow is provided on the pile cap.
[0010] Furthermore, the drainage pipe is inserted into the top of the sand pile by no less than 1 m.
[0011] Compared with the prior art, the present invention has the following beneficial effects:
[0012] The present invention promotes drainage and consolidation of deep soft soil below the pipe piles with sand piles without increasing the length of the pipe piles, and uses the pipe piles as drainage channels to drain the foundation. The composite pipe piles composed of the pipe pile body and the sand piles can strictly limit the post-construction settlement of the pipe pile depth range, and under the pre-compression measures at the top of the pile, effectively promote the drainage and consolidation of the soil layer corresponding to the sand pile depth range, thereby reducing the post-construction settlement of the soil layer within the sand pile range. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a structural schematic diagram of the present invention;
[0014] Figure 2 It is a schematic diagram of the pile end structure of the pipe pile body in the present invention.
[0015] Reference numerals:
[0016] 1-pile body, 2-pile end, 3-pile top, 4-guide ring, 5-sand pile, 6-drainage pipe, 7-pile cap, 8-rebar, 9-round steel plate, 10-protective cover. DETAILED DESCRIPTION
[0017] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.
[0018] like Figure 1 and Figure 2 As shown, a composite pipe pile with drainage and consolidation functions includes a pipe pile body 1, a pile end 2 at the bottom of the pipe pile body 1 is provided with a guide ring 4, a pile cap 7 is fixedly provided at the pile top 3 on the top of the pipe pile body 1, and a drainage pipe 6 is passed through the pile cap 7 and the pipe pile body 1; the lower part of the guide ring 4 extends downward in a cone shape to form a ring knife-shaped tip; the pile end 2 is provided with a sand pile 5 extending downward from the inside of the pile end 2; the lower end of the drainage pipe 6 is inserted into the sand pile 5 and is evenly provided with perforations, the lower end of the drainage pipe 6 is wrapped with geotextile, and the upper end of the drainage pipe 6 passes through the pile cap 7.
[0019] The upper part of the guide ring 4 extends into the pile end 2 and is in close contact with the inner wall of the pile end 2. The thickness of the top of the guide ring 4 extending into the pile end 2 gradually decreases, so that the top of the guide ring 4 is wedge-shaped. Its function is to guide the positioning of the long spiral drill bit, ensure that the center point and verticality of the drill hole are consistent with the pile body 1, reduce the possibility of the drill bit colliding with the inner wall of the pile body 1, and protect the pile body 1. The lower part of the guide ring 4 extends downward in a cone shape to form a ring knife-shaped tip, which serves as a pile tip to reduce the resistance of the pile into the soil. Depending on the needs of the soil layer, its thickness can also be gradually reduced downward.
[0020] The pile cap 7 is cast-in-place reinforced concrete, and a steel bar 8 structure is arranged inside the pile cap 7. The steel bar 8 extends downward into the pile body 1 and is welded with a circular steel plate 9. The circular steel plate 9 deep inside the pile body 1 can be used as a plugging end of the cast-in-place concrete.
[0021] like Figure 1 As shown, after the pipe pile body 1 is in place, the present invention uses a long spiral method to drill a hole from the pile end 2 downward through the inside of the pipe pile body 1, and the diameter of the drill bit should be slightly smaller than the inner diameter of the guide ring 4. After the hole is formed, sand is poured into the hole to form a sand pile 5. The top of the sand pile 5 is not less than 0.5m higher than the pile end 2, so that the pipe pile body 1 and the sand pile 5 are connected as a whole. From the pile end 2 downward, the effective length of the sand pile 5 is L2.
[0022] During the preloading period, the backfill at the pile top 3 and the preloading load are partially transferred to the pile end 2 through the rigid pipe pile body 1, acting on the original soft soil around the sand pile 5. With the support of the drainage channel formed by the sand pile 5 and the drainage pipe 6, the soft soil corresponding to the L2 range is drained and consolidated, and the water is discharged from the drainage outlet at the pile top 3 under the action of the super void pressure. The pipe pile body 1 is a precast concrete pipe pile, and the types include but are not limited to prestressed concrete pipe piles, prestressed thin-walled concrete pipe piles, prestressed high-strength concrete pipe piles, etc. The pipe pile body 1 is constructed by static pressure or hammering technology, and the pile is sunk to a predetermined depth. There are two drainage outlets for the pipe pile: direct discharge inside the drainage cushion layer and external discharge through the pipeline. The drainage pipe outlet can directly drain water into the cushion layer and flow freely out of the roadbed through the drainage cushion layer. Multiple piles can also be connected in series, extending to the outside of the roadbed through a transverse pipeline, and can be connected to a vacuum exhaust device to achieve a vacuum preloading effect.
[0023] The composite pipe pile composed of the pipe pile body 1 and the sand pile 5 can strictly limit the post-construction settlement of the pipe pile depth range, and under the pre-loading measure of the pile top, effectively promote the drainage and consolidation of the soil layer corresponding to the sand pile depth range L2, thereby reducing the post-construction settlement of the L2 soil layer. Compared with the pipe piles of L1+L2 length, the composite pipe pile has obvious cost advantages, and compared with the pipe piles of L1 length, the composite pipe pile has a significantly better settlement control effect.
[0024] The upper end of the drainage pipe 6 is provided with an elbow and a threaded interface at a position 10 cm above the pile cap 7 for external drainage equipment. The pile cap 7 is provided with a protective cover 10 covering the elbow. The protective cover 10 can prevent the elbow of the drainage pipe 6 from being damaged by the compaction of the cushion layer above the pile cap 7. The protective cover 10 is made of a bent steel plate and is pre-buried on the pile cap 9, with a depth of no more than 40 mm in the concrete of the pile cap 9. The drainage pipe 6 is inserted into the top of the sand pile 5 for no less than 1 m, so that the water inlet is surrounded by sand and soil, ensuring that the water in the surrounding soft soil can penetrate smoothly into the water inlet through the sand and soil.
[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A composite pipe pile with drainage and consolidation functions, comprising a pipe pile body (1), characterized in that: The pile end (2) at the bottom of the pipe pile body (1) is provided with a guide ring (4), the pile top (3) at the top of the pipe pile body (1) is fixedly provided with a pile cap (7), and the pile cap (7) and the pipe pile body (1) are jointly provided with a drainage pipe (6); the lower part of the guide ring (4) extends downward in a cone shape to form a ring knife-shaped tip; the pile end (2) is provided with a sand pile (5) extending downward from the inside of the pile end (2); the lower end of the drainage pipe (6) is inserted into the sand pile (5) and is evenly provided with perforations, the lower end of the drainage pipe (6) is wrapped with geotextile, and the upper end of the drainage pipe (6) passes through the pile cap (7).
2. The composite pipe pile with drainage and consolidation function according to claim 1, characterized in that: The upper part of the guide ring (4) extends into the pile end (2) and is in close contact with the inner wall of the pile end (2), and the thickness of the top of the guide ring (4) extending into the pile end (2) gradually decreases.
3. The composite pipe pile with drainage and consolidation function according to claim 1, characterized in that: The pile cap (7) is cast-in-place reinforced concrete. A steel bar (8) structure is arranged inside the pile cap (7). The steel bar (8) extends downward into the pile body (1) and is welded with a circular steel plate (9).
4. The composite pipe pile with drainage and consolidation function according to claim 1, characterized in that: The top of the sand pile (5) is not less than 0.5 m higher than the pile end (2).
5. The composite pipe pile with drainage and consolidation function according to claim 1, characterized in that: The upper end of the drainage pipe (6) is provided with an elbow and a threaded interface at a position 10 cm higher than the pile cap (7), and a protective cover (10) covering the elbow is provided on the pile cap (7).
6. The composite pipe pile with drainage and consolidation function according to claim 5, characterized in that: The drainage pipe (6) is inserted into the top of the sand pile (5) by no less than 1 m.