Prefabricated hollow pile foundation and high-pressure grouting method thereof

Abstract

The invention provides a prefabricated hollow pile foundation and a high-pressure grouting method thereof. The prefabricated hollow pile foundation comprises a flexible bag, a steel pile tip and a connecting plate, and the top of the flexible bag is connected with the bottom of a prefabricated hollow pile through the connecting plate; a grouting port valve port in the middle of the connecting plate is connected with a grouting pipe in the prefabricated hollow pile; and a steel pile tip is mounted at the bottom of the flexible bag. After pile sinking, through high-pressure grouting, the flexible bag expands and extrudes a soil body at the pile end, the pile end is expanded, meanwhile, a soil layer at the pile end is compacted, the bearing capacity of the pile end is greatly improved, pile settlement is reduced, meanwhile, the grouting amount is controllable, and the bearing capacity of the pile is controllable.

Description

Technical Field

[0001] The invention relates to the technical field of construction, and in particular to a prefabricated hollow pile foundation and a high-pressure grouting method thereof. Background Art

[0002] Post-grouting technology for precast piles is a technology developed in recent years. It uses the cavity in the middle of precast hollow piles (pipe piles or hollow square piles) to embed grouting pipes, which can greatly improve the bearing capacity of the soil layer at the pile end and near the pile end, thereby greatly improving the bearing capacity of a single pile and reducing pile foundation settlement. However, it has disadvantages such as difficult to control the quality of grouting and long construction time. The technology of ramming carrier piles in precast hollow piles uses the cavity in the pile core for carrier construction, which can also greatly improve the bearing capacity of a single pile and reduce pile foundation settlement. The quality is easy to control, but the construction of the carrier is slow. Each pile needs to be rammed 200 to 300 times, and the construction time of each carrier is about 2 hours. It requires more working hours and is time-consuming and labor-intensive. Summary of the invention

[0003] The purpose of the present invention is to provide a prefabricated hollow pile foundation and a high-pressure grouting method thereof, which can expand the pile end by high-pressure grouting while compacting the soil layer at the pile end, thereby greatly improving the bearing capacity of the pile end and reducing pile settlement.

[0004] To achieve the above-mentioned purpose, the present invention proposes a prefabricated hollow pile foundation, comprising a flexible bag, a steel pile tip and a connecting plate, wherein the top of the flexible bag is connected to the bottom of the prefabricated hollow pile through the connecting plate; the grouting port valve port in the middle of the connecting plate is connected to the grouting pipe in the prefabricated hollow pile; the steel pile tip is installed at the bottom of the flexible bag, and based on the high-pressure grouting method, the flexible bag is expanded after the pile is sunk, thereby improving the bearing capacity of the pile end and reducing the pile settlement.

[0005] Furthermore, the flexible bag is compressed between the connecting plate and the one-way check valve in a folded state, so that less space is occupied for pile sinking, which is convenient for transportation.

[0006] Furthermore, the connecting plate is fixed to the bottom of the prefabricated hollow pile by bolts or welding.

[0007] Furthermore, a rubber sealing ring is provided between the connecting plate and the prefabricated hollow pile.

[0008] Furthermore, uniformly distributed steel nails are sewn or bonded on the surface of the flexible bag.

[0009] The present invention also provides a high-pressure grouting method for a prefabricated hollow pile foundation. After the prefabricated hollow pile is sunk, high-pressure grouting is performed into the flexible bag through a grouting pipe, and the flexible bag expands and squeezes the soil at the pile end.

[0010] Compared with the prior art, the advantages of the present invention are:

[0011] 1. The present invention adopts a high-pressure grouting method to expand the pile end and compact the soil layer at the pile end, thereby greatly improving the bearing capacity of the pile end and reducing pile settlement. At the same time, the grouting volume is controllable and the bearing capacity of the pile is controllable.

[0012] 2. The high-pressure grouting construction method of the present invention is convenient, has a fast construction speed, and saves labor.

[0013] 3. The foundation of the present invention is simple to manufacture, can be mass-produced, and can be reliably connected with prefabricated hollow piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a perspective view of the appearance of a prefabricated hollow pile foundation in an embodiment of the present invention;

[0015] Figure 2 is a cross-sectional view of a prefabricated hollow pile foundation in an embodiment of the present invention;

[0016] Figure 3 is a perspective view of the appearance of the flexible bag in a folded state in an embodiment of the present invention;

[0017] Figure 4 It is a perspective view of the flexible bag in the expanded state and after grouting in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further described below.

[0019] like Figure 1 and Figure 2 As shown, the present invention proposes a prefabricated hollow pile foundation, which consists of a flexible bag 22, a steel pile tip 23 and a connecting plate 21. The top of the flexible bag 22 is connected to the bottom of the prefabricated hollow pile 1 through the connecting plate 21; the central grouting hole of the connecting plate 21 is connected to the grouting pipe 3 in the prefabricated hollow pile 1; and the steel pile tip 23 is installed at the bottom of the flexible bag 22.

[0020] The present invention also proposes a high-pressure grouting method for a prefabricated hollow pile foundation, wherein a prefabricated hollow pile 1 is sunk and then a structural filler 4 is grouted under high pressure. After grouting, the flexible bag 22 expands and squeezes the soil at the pile end, thereby increasing the bearing capacity of the pile end and reducing pile settlement.

[0021] In this embodiment, if Figure 3 and Figure 4 As shown, the prefabricated hollow pile foundation 2 is mainly in two states: the initial state of pile sinking and the expanded state after pile sinking. In the initial state, the flexible bag 22 is folded and compressed between the steel pile tip 23 and the connecting plate 21, which takes up less space before pile sinking and is easy to transport.

[0022] The connecting plate 21 is an end plate with a grouting hole in the middle. The end plate is fixed to the bottom of the prefabricated hollow pile 1 by bolts. In other embodiments, welding can also be used for connection.

[0023] In this embodiment, a rubber sealing ring 25 is provided between the connecting plate 21 and the prefabricated hollow pile 1 to prevent the structural filler from leaking out of the bag during grouting. Figure 4 As shown, the surface of the flexible bag 22 is sewn with uniformly distributed steel nails 24, and after expansion, the steel nails 24 are inserted into the soil layer, thereby ensuring the firmness of the connection between the prefabricated hollow pile foundation 2 and the end pile soil layer, greatly improving the pile end bearing capacity and reducing pile settlement.

[0024] In this embodiment, the flexible bag 22 is polyester fiber, and in other embodiments, the flexible bag 22 can also be nylon, polyurethane, polyurethane fabric, polyamide, rubber, etc. In this embodiment, the structural filler of the grouting is cement mortar, and in other embodiments, it can also be fine stone concrete, preferably fine stone concrete mixed with accelerating setting agent and micro expansion agent.

[0025] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.

Claims

1. A prefabricated hollow pile foundation, characterized in that: It includes a flexible bag, a steel pile tip and a connecting plate. The top of the flexible bag is connected to the bottom of the prefabricated hollow pile through the connecting plate. The grouting port valve in the middle of the connecting plate is connected to the grouting pipe in the prefabricated hollow pile. The steel pile tip is installed at the bottom of the flexible bag.

2. The prefabricated hollow pile foundation according to claim 1, characterized in that: In an initial state, the flexible bag is in a folded state and compressed between the steel pile tip and the connecting plate.

3. The prefabricated hollow pile foundation according to claim 1, characterized in that: The connecting plate is fixed to the bottom of the prefabricated hollow pile by bolts or welding.

4. The prefabricated hollow pile foundation according to claim 1, characterized in that: A rubber sealing ring is provided between the connecting plate and the prefabricated hollow pile.

5. The prefabricated hollow pile foundation according to claim 1, characterized in that: The surface of the flexible bag is sewn or bonded with uniformly distributed steel nails.

6. A high-pressure grouting method for a prefabricated hollow pile foundation, using the prefabricated hollow pile foundation as claimed in any one of claims 1 to 5, characterized in that: After the prefabricated hollow pile is sunk, high-pressure grouting is injected into the flexible bag through the grouting pipe, and the flexible bag expands and squeezes the soil at the pile end.

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