Prefabricated hollow pile foundation and method for firstly exploding and expanding and then grouting

Abstract

The prefabricated hollow pile foundation comprises a flexible bag, a steel pile tip and a blasting material, and the top of the flexible bag is connected with the bottom of a prefabricated hollow pile through a one-way check valve; a valve port of the one-way check valve is connected with a grouting pipe in the prefabricated hollow pile; a steel pile tip is installed at the bottom of the flexible bag, and blasting materials are embedded in the flexible bag. The blasting material is detonated after pile sinking, the flexible bag expands and extrudes the soil body at the pile end, then the structure filler is poured into the flexible bag to complete foundation grouting, the blasting principle is adopted, the soil layer at the pile end is compacted while the pile end is expanded, the bearing capacity of the pile end is greatly improved, and pile settlement is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of construction, and in particular to a prefabricated hollow pile foundation and a method for blasting and expanding before grouting. 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 method of blasting and then grouting which uses the blasting principle to expand the pile end and compact the soil layer at the pile end, greatly improve the bearing capacity of the pile end and reduce pile settlement.

[0004] To achieve the above-mentioned purpose, the present invention proposes a prefabricated hollow pile foundation, including a flexible bag, a steel pile tip and blasting materials. The top of the flexible bag is connected to the bottom of the prefabricated hollow pile through a one-way check valve; the valve port of the one-way check valve is connected to the grouting pipe in the prefabricated hollow pile; the bottom of the flexible bag is equipped with a steel pile tip, and blasting materials are pre-buried inside the flexible bag. Through the blasting principle, the flexible bag after the pile is sunk is expanded by explosion, and grouting is poured into the flexible bag to improve the pile end bearing capacity and reduce pile settlement.

[0005] Furthermore, the flexible bag is compressed between the steel pile tip and the one-way check valve in a folded state, taking up less space before explosion and expansion, and is easy to transport.

[0006] The one-way check valve is an end plate, and the middle part of the end plate is the check valve body.

[0007] Furthermore, the one-way check valve is fixed to the bottom of the prefabricated hollow pile by bolts or welding.

[0008] Furthermore, a rubber sealing ring is provided between the one-way check valve and the prefabricated hollow pile.

[0009] Furthermore, uniformly distributed steel nails are sewn or bonded on the surface of the flexible bag.

[0010] The present invention also proposes a method of first blasting and then grouting for a prefabricated hollow pile foundation. After the prefabricated hollow pile is sunk, the blasting material is detonated, the flexible bag expands and squeezes the soil at the pile end, and then the structural filler is poured into the flexible bag after the explosion through the grouting pipe in the prefabricated hollow pile.

[0011] Compared with the prior art, the advantages of the present invention are:

[0012] 1. Blasting principle: expanding the pile end and compacting the soil layer at the pile end, greatly improving the bearing capacity of the pile end and reducing pile settlement.

[0013] 2. The construction method is convenient, the construction speed is fast, and labor is saved.

[0014] 3. The container is easy to make, can be mass-produced, and can be reliably connected to prefabricated hollow piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a perspective view of the appearance of a prefabricated hollow pile foundation in an embodiment of the present invention;

[0016] Figure 2 is a cross-sectional view of a prefabricated hollow pile foundation in an embodiment of the present invention;

[0017] Figure 3 is a perspective view of the appearance of the flexible bag in a folded state in an embodiment of the present invention;

[0018] Figure 4 It is a perspective view of the flexible bag in the exploded state and after grouting in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] 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.

[0020] 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 an blasting material 3. The top of the flexible bag 22 is connected to the bottom of the prefabricated hollow pile 1 through a one-way check valve 21; the valve port of the one-way check valve 21 is connected to the grouting pipe in the prefabricated hollow pile 1; the steel pile tip 23 is installed at the bottom of the flexible bag 22, and the blasting material 3 is pre-buried inside the flexible bag 22.

[0021] The present invention also proposes a method for grouting after blasting for a prefabricated hollow pile foundation, in which after the prefabricated hollow pile 1 is sunk, the blasting material 3 is detonated, the flexible bag 22 expands and squeezes the soil at the pile end, and then the structural filler 4 is poured into the expanded flexible bag 22 through the grouting pipe in the prefabricated hollow pile 1. After the flexible bag 22 is blasted after the pile is sunk, grouting is poured into the flexible bag 22 to improve the bearing capacity of the pile end and reduce the pile settlement.

[0022] 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 before explosion expansion and the explosion expansion state after pile sinking. In the initial state, the flexible bag 22 is folded and compressed between the steel pile tip 23 and the one-way check valve 21, which occupies less space before explosion expansion and is easy to transport.

[0023] The one-way check valve 21 is an end plate, the middle of the end plate is the check valve body, and has a valve port. The end plate is fixed to the bottom of the prefabricated hollow pile 1 by bolts, and in other embodiments, it can also be connected by welding.

[0024] In this embodiment, a rubber sealing ring 25 is provided between the one-way check valve 21 and the prefabricated hollow pile 1 to prevent the structural filler 4 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 the explosion, 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.

[0025] 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 and other materials. In this embodiment, the blasting material 3 can be a gas explosion, and in other embodiments, it can also be a blasting charge. In this embodiment, the grouting structural filler 4 is cement mortar, and in other embodiments, it can also be fine stone concrete, preferably fine stone concrete mixed with an accelerating setting agent and a micro-expansion agent.

[0026] 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 blasting materials. The top of the flexible bag is connected to the bottom of the prefabricated hollow pile through a one-way check valve; the valve port of the one-way check valve 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 the blasting material is pre-buried in 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 one-way check valve.

3. The prefabricated hollow pile foundation according to claim 1, characterized in that: The one-way check valve is an end plate, and the middle part of the end plate is the check valve body.

4. The prefabricated hollow pile foundation according to claim 3, characterized in that: The one-way check valve is fixed to the bottom of the prefabricated hollow pile by bolts or welding.

5. The prefabricated hollow pile foundation according to claim 3, characterized in that: A rubber sealing ring is provided between the one-way check valve and the prefabricated hollow pile.

6. 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.

7. A method for blasting expansion followed by grouting of a prefabricated hollow pile foundation, using the prefabricated hollow pile foundation as claimed in any one of claims 1 to 6, characterized in that: After the prefabricated hollow pile is sunk, the blasting material is detonated, the flexible bag expands and squeezes the soil at the pile end, and then the structural filler is poured into the expanded flexible bag through the grouting pipe in the prefabricated hollow pile.

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