Blasting prefabricated friction pile

Abstract

The utility model belongs to the technical field of pile foundation engineering construction, and particularly relates to a blasting prefabricated friction pile which comprises a pile cap, a pile body and a pile tip, an annular groove is formed in the pile body, an annular steel hoop is sleeved on the periphery of the annular groove, a flange ring is arranged outside the annular steel hoop, a gunpowder ring is wrapped on the periphery of the annular steel hoop, and an annular hoop is wrapped on the periphery of the gunpowder ring. A grouting hole is formed in the pile cap, the grouting hole downwards penetrates through the pile body to the upper surface of the annular groove in the bottommost end, a grouting pipe is fixed in the grouting hole, a detonating cord penetrates through the grouting pipe, and the detonating cord is connected with the gunpowder ring. By means of micro blasting and grouting treatment on the annular local portion of the pile body, a side supplementing annular grouting cavity is formed around the friction pile body, the friction force between the friction pile and soil is improved, the strength and rigidity of the soil around the pile body can be improved, deformation and sinking of the pile are reduced, and the side friction resistance of a single pile is improved; and the distance between the adjacent piles can be increased, and the construction cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of pile foundation engineering construction, in particular to a blasting prefabricated friction pile. Background Art

[0002] In the field of pile foundation construction technology, friction piles, also known as side resistance piles, are a commonly used foundation bearing structure. Friction piles use the side resistance of the soil to bear the load of the building, and transfer the load to the soil through friction, thereby achieving the purpose of increasing the bearing capacity and stabilizing the building. Friction piles are easy to construct and relatively low in cost, but they also have their own defects and shortcomings in the actual construction process. When the length of the prefabricated friction pile exceeds a certain range, under the action of the pile top load, the upper part of the pile will soften due to the large relative displacement of the pile and soil, causing the lateral friction resistance around the pile body to soften, resulting in a gradual decrease in the upper bearing capacity of the foundation pile. With the increase in the settlement of the pile top, the pile will fail due to the excessive settlement of its top under the premise that the overall bearing capacity meets the requirements. At this time, the upper bearing capacity of the pile reaches the limit value or enters the softening bearing stage, while the friction around the lower part of the pile has not yet been fully exerted. Therefore, it is urgent to invent a new structural form that can increase the friction of existing prefabricated friction piles, so that the pile top settlement can fully utilize the pile body friction of the prefabricated friction pile to improve the vertical load bearing capacity while meeting the deformation requirements of the superstructure, thereby reducing the project cost, ensuring structural safety and saving social resources. Summary of the invention

[0003] The problem to be solved by the present invention is to overcome the shortcomings of the background technology and provide a blasting prefabricated friction pile.

[0004] The present invention is achieved through the following technical solutions:

[0005] A blasting prefabricated friction pile comprises a pile cap, a pile body and a pile tip, wherein the pile body is provided with a plurality of annular grooves from top to bottom, an annular steel hoop is sleeved on the outer circumference of the annular groove, flange rings are provided on the upper and lower end faces of the annular steel hoop, a gunpowder ring is wrapped around the outer circumference of the annular steel hoop, an annular clamp is wrapped around the outer circumference of the gunpowder ring, and the outer diameter of the annular clamp is equal to the outer diameter of the pile body; a plurality of grouting holes are evenly arranged around the pile cap, the grouting holes penetrate downward through the pile body to the upper surface of the annular groove at the bottom, reserved holes corresponding to the grouting holes are provided on the flange ring, a grouting pipe is fixed in the grouting hole, a detonating line is passed through the grouting pipe, and the detonating line is connected to the gunpowder ring.

[0006] Preferably, there are four grouting holes.

[0007] Preferably, the annular steel hoop has a thickness of 0.5-1.5 mm.

[0008] Preferably, the annular hoop is an aluminum ring.

[0009] Preferably, the bottom end of the grouting pipe is welded to the reserved hole of the upper flange ring of the annular steel hoop at the bottom.

[0010] The present invention aims at the defects and shortcomings of the existing prefabricated friction piles. By performing local micro-annular blasting and grouting treatment on the pile body, a side-filling annular grouting cavity is formed around the friction pile body, thereby improving the friction between the friction pile and the soil. It can not only improve the strength and rigidity of the soil around the pile body, reduce the deformation and sinking of the pile, and increase the lateral friction resistance of a single pile, but also increase the spacing between adjacent piles and reduce construction costs. The larger the distance between adjacent piles, the smaller the mutual influence, thereby reducing the pile group effect. Therefore, the friction piles of the present invention can shorten the pile body length of the friction pile and save engineering costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the structure after blasting of this embodiment;

[0012] Figure 2 This is a schematic diagram of the pile body and pile tip structure of this embodiment;

[0013] Figure 3 This is a schematic diagram of the structure of the annular steel hoop in this embodiment;

[0014] Figure 4 This is a schematic diagram of the powder ring structure of this embodiment;

[0015] Figure 5 This is a schematic diagram of the annular hoop structure of this embodiment;

[0016] Figure 6 This is a schematic diagram of the cross-sectional structure of this embodiment;

[0017] Figure 7 This is a schematic diagram of the upper cross-sectional structure of this embodiment;

[0018] Figure 8 This is a schematic diagram of the grouting pipe and the annular steel hoop structure of this embodiment;

[0019] Fig. 9 It is a schematic diagram of the local structure of this embodiment;

[0020] Fig.10 This is a schematic diagram of the overall structure of this embodiment after installation.

[0021] In the figure, 1 is pile cap, 2 is pile body, 3 is pile tip, 4 is annular groove, 5 is annular steel hoop, 6 is flange ring, 7 is gunpowder ring, 8 is annular clamp, 9 is grouting hole, 10 is reserved hole, 11 is grouting pipe, and 12 is detonating wire. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0023] The prefabricated friction pile of this embodiment includes three parts: a pile cap 1, a pile body 2 and a pile tip 3. The present invention improves the pile body 2, and a plurality of annular grooves 4 are provided on the pile body 2 from top to bottom. Depending on the situation, only one annular groove 4 can be provided, or multiple annular grooves 4 can be provided. The diameter of the pile body 2 at the annular groove 4 is relatively small, and an annular steel hoop 5 is sleeved on the outer periphery of the annular groove 4. The upper end face and the lower end face of the annular steel hoop 5 are both provided with flange rings 6 outwardly. The annular steel hoop 5 is used to protect the pile body 2 when the gunpowder explodes. Therefore, the annular steel hoop 5 is made of steel, and the thickness of the annular steel hoop 5 is preferably 0.5-1.5 mm. A gunpowder ring 7 is wrapped around the outer periphery of the annular steel hoop 5, and the gunpowder ring 7 makes the gunpowder into an annular body. An annular hoop 8 is wrapped around the outer periphery of the gunpowder ring 7, and the outer diameter of the annular hoop 8 is equal to the outer diameter of the pile body 2. The material hardness of the annular hoop 8 is less than the material hardness of the annular steel hoop 5, and at the same time, the gunpowder can be exploded. Therefore, the annular hoop 8 of this embodiment is preferably an aluminum ring.

[0024] A plurality of grouting holes 9 are evenly arranged around the upper surface of the pile cap 1. In this embodiment, four grouting holes 9 are arranged. The grouting holes 9 penetrate the pile body 2 downward to the upper surface of the annular groove 4 at the bottom. The grouting holes 9 are disconnected at the annular groove 4, that is, there is no grouting hole 9 on the pile body 2 at the annular groove 4. A reserved hole 10 corresponding to the grouting hole 9 is arranged on the flange ring 6 of the annular steel hoop 5. The reserved hole 10 is aligned and connected with the grouting hole 9. A grouting pipe 11 is fixed in the grouting hole 9. There is no grouting pipe 11 at the annular groove 4, that is, the grouting pipe 11 is disconnected at the annular groove 4 and divided into sections. The grouting pipe 11 is connected with the reserved hole 10. The bottom end of the lowest section of the grouting pipe 11 is welded to the reserved hole 10 of the upper flange ring 6 of the lowest annular steel hoop 5, and is aligned and connected with the reserved hole 10. The upper end of the grouting pipe 11 is not higher than the upper surface of the pile cap 1. Generally, the upper end of the grouting pipe 11 is flush with the pile cap 1. A detonating wire 12 is passed through the grouting pipe 11 from top to bottom, and the detonating wire 12 connects the powder rings 7 in each annular groove 4, so as to connect the powder rings 7 in series.

[0025] During construction, the prefabricated friction pile is pressed to the designed elevation through the pile driver, and then the detonating wire 12 is ignited. When the detonating wire 12 burns to the gunpowder ring 7 at the annular groove 4, the gunpowder ring 7 is detonated. The detonating wire 12 detonates all the gunpowder rings 7 downward in sequence. The gunpowder ring 7 explodes the annular clamp 8 and simultaneously blasts an annular space around the annular groove 4. Then the grouting machine is connected to the grouting pipe 11, and the grouting machine is used to grout the annular space to form an annular grouting cavity. The formed grouting cavity can not only improve the strength and stiffness of the soil around the pile body 2, but also reduce the deformation and sinking of the pile, thereby improving the lateral friction resistance of the pile body 2.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A blasting prefabricated friction pile, comprising a pile cap (1), a pile body (2) and a pile tip (3), characterized in that: The pile body (2) is provided with a plurality of annular grooves (4) from top to bottom, an annular steel hoop (5) is sleeved on the outer circumference of the annular groove (4), the upper end surface and the lower end surface of the annular steel hoop (5) are both provided with flange rings (6), a gunpowder ring (7) is wrapped around the outer circumference of the annular steel hoop (5), and an annular hoop (8) is wrapped around the outer circumference of the gunpowder ring (7), and the outer diameter of the annular hoop (8) is equal to the outer diameter of the pile body (2); a plurality of grouting holes (9) are evenly arranged around the pile cap (1), the grouting holes (9) penetrate downwardly through the pile body (2) to the upper surface of the annular groove (4) at the bottom, a reserved hole (10) corresponding to the grouting hole (9) is provided on the flange ring (6), a grouting pipe (11) is fixed in the grouting hole (9), a detonating wire (12) is passed through the grouting pipe (11), and the detonating wire (12) is connected to the gunpowder ring (7).

2. The blasting prefabricated friction pile according to claim 1, characterized in that: There are four grouting holes (9).

3. The blasting prefabricated friction pile according to claim 1, characterized in that: The annular steel hoop (5) has a thickness of 0.5-1.5 mm.

4. The blasting prefabricated friction pile according to claim 1, characterized in that: The annular hoop (8) is an aluminum ring.

5. The blasting prefabricated friction pile according to claim 1, characterized in that: The bottom end of the grouting pipe (11) is welded to the reserved hole (10) of the upper flange ring (6) of the annular steel hoop (5) at the bottom.

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