Device for expanding pile head through dry operation pore-forming

Abstract

The utility model discloses a dry operation hole-forming pile head expanding device, and belongs to the technical field of foundation treatment engineering. Comprising a regulating valve, a high-pressure air chamber, a material suction pipeline and a base, a plurality of gas spraying holes are formed in the side wall of the high-pressure gas chamber from top to bottom; the top of the high-pressure air chamber is connected with an air compressor; the bottom end of the material suction pipeline penetrates out of the bottom of the high-pressure air chamber, and the top end of the material suction pipeline penetrates out of the top of the high-pressure air chamber. The top end of the suction pipeline is connected with a vacuum pump suction machine; a material suction opening is formed in the bottom end of the material suction pipeline; the bottom of the suction port is connected with a base; the adjusting valve is arranged on the outer wall of the high-pressure air chamber and used for opening and closing the multiple air spraying holes; the utility model has the characteristics that the pile head can be conveniently expanded, and loose soil at the pile end can be timely cleaned; the problems that an existing pile head is poor in expansion safety, and virtual soil is difficult to discharge are solved.

Description

Technical Field

[0001] This utility model belongs to the field of foundation treatment engineering technology, specifically a device for dry drilling to enlarge pile heads. Background Technology

[0002] Dry-work pile foundation construction refers to a method of pile foundation construction in soil with a low groundwater level or no groundwater within the drilling depth, without the need for mud slurry for wall protection. Dry-work pile head enlargement, also known as borehole enlargement, is a common construction method in civil engineering, aiming to increase the pile's bearing capacity by widening the pile base. Enlarging the pile head's bearing area significantly increases the end resistance and is more conducive to the utilization of lateral resistance, thereby improving the overall bearing capacity of a single pile. In engineering practice, various techniques for enlarging pile heads have been proposed, such as rammed piles, spur piles, and manually excavated piles with enlarged bases.

[0003] In engineering practice, soil layers that can be constructed using dry drilling methods are generally those with good compaction and verticality. When using the ramming and expansion method to enlarge the pile head, the pile head size may not meet the design requirements due to the relatively dense soil layer at the pile tip, or it may require greater costs. In addition, the diameter of internally rammed cast-in-place piles is generally not large, resulting in less flexibility.

[0004] Currently, the most common method for enlarging pile heads in dry drilling operations is borehole reaming. This involves drilling the pile hole to a predetermined depth using a constant-diameter drilling method, then replacing it with a reaming drill bit. The reaming cutting edge of the drill bit is spread and rotated to cut the strata, thereby enlarging the bottom of the hole. Afterward, a reinforcing cage is placed in the hole, and concrete is poured in to form an enlarged-base pile, thus achieving a greater bearing capacity.

[0005] However, regardless of the device or method used for drilling and enlarging the pile head, traditional dry-work pile foundation construction often involves a significant amount of loose soil at the pile tip, requiring manual operation, which is highly unsafe. Furthermore, dry-work drilling presents challenges in effectively cleaning the loose soil at the pile bottom and enlarging the pile head. Explosive enlargement piles, which involve placing explosives at the bottom of the hole to create an enlarged pile head, are obviously less safe and environmentally friendly, and since explosives are controlled substances, they are rarely used now. During recompaction pile construction, the quality and size of the enlarged head are influenced by numerous factors, resulting in significant variations in the pile foundation's bearing capacity, as the bearing stratum at the pile tip is typically dense soil. Utility Model Content

[0006] This utility model overcomes the shortcomings of the prior art and proposes a device for dry drilling to enlarge pile heads;

[0007] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0008] A device for dry drilling to enlarge pile heads includes a regulating valve, a high-pressure air chamber, a suction pipe, and a base. The high-pressure air chamber has multiple air jet holes arranged from top to bottom on its side wall. An air compressor is connected to the top of the high-pressure air chamber. The bottom end of the suction pipe extends from the bottom of the high-pressure air chamber, and the top end extends from the top of the high-pressure air chamber. A vacuum pump is connected to the top end of the suction pipe. A suction port is provided at the bottom end of the suction pipe. The base is connected to the bottom of the suction port. The regulating valve is located on the outer wall of the high-pressure air chamber and is used to open and close the multiple air jet holes.

[0009] Furthermore, the high-pressure air chamber has a cylindrical structure; the jet holes are evenly distributed on the side wall of the high-pressure air chamber.

[0010] Furthermore, the regulating valve has a cylindrical sleeve structure, and the inner wall of the regulating valve is slidably connected to the outer wall of the high-pressure gas chamber.

[0011] Furthermore, a telescopic motor is connected to the top of the regulating valve.

[0012] Furthermore, the bottom end of the suction pipe is connected to four symmetrically arranged suction ports; the base is located between the four suction ports.

[0013] Furthermore, the base has a conical cylindrical structure.

[0014] The beneficial effects of this utility model compared to the prior art are as follows:

[0015] 1. This utility model is simple and lightweight, and can expand the pile head while cleaning the loose soil at the pile bottom, ensuring the quality of pile formation and achieving the purpose of improving the bearing capacity of the pile foundation and saving investment.

[0016] 2. This utility model features convenient pile head enlargement and timely removal of loose soil at the pile tip. Compared to manual pile head enlargement and manual bottom cleaning, it offers greater safety; it is also safer and more environmentally friendly than blast pile enlargement; since the bearing layer at the pile tip is generally a dense soil layer, this utility model achieves the required dimensions more easily and at a lower cost than rammed pile enlargement. This device utilizes controlled high-pressure fine airflow to impact the sidewalls, while the central tube simultaneously removes soil particles, ensuring pile quality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the dry drilling and pile head enlargement device described in this utility model;

[0018] Figure label:

[0019] 1. Regulating valve; 2. High-pressure air chamber; 3. Suction pipe; 4. Base; 5. Air jet; 6. Suction port; 7. Air compressor; 8. Vacuum pump suction machine. Detailed Implementation

[0020] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, this utility model will be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit it. The technical solution of this utility model will be described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0021] See Figure 1 This embodiment proposes a device for dry drilling to enlarge pile heads, including a regulating valve 1, a high-pressure air chamber 2, a suction pipe 3, and a base 4. In this embodiment, the high-pressure air chamber 2 is a cylindrical structure. Multiple air jet holes 5 are provided on the side wall of the high-pressure air chamber 2 from the middle to the bottom. The air jet holes 5 are evenly distributed on the side wall of the high-pressure air chamber 2. An air compressor 7 is connected to the top of the high-pressure air chamber 2. With the air compressor 7 and the air jet holes 5, high-pressure air can be injected into the high-pressure air chamber 2 by the air compressor 7. The high-pressure air is ejected through the air jet holes 5, and the high-pressure airflow can then impact the soil on the side of the pile to achieve pile head enlargement.

[0022] The regulating valve 1 is mounted on the outer wall of the high-pressure air chamber 2 and is used to open and close multiple jet holes 5. In this embodiment, the regulating valve 1 is a cylindrical sleeve structure, and a telescopic motor is connected to the top of the regulating valve 1. The inner wall of the regulating valve 1 is slidably sealed to the outer wall of the high-pressure air chamber 2, which can be achieved by placing a rubber gasket on the inner wall of the regulating valve 1 to form a seal. As the regulating valve 1 is gradually raised, the number of jet holes 5 that open increases, and the impact force of the high-pressure airflow increases; as the regulating valve 1 is gradually pushed down, the number of jet holes 5 that open decreases, and the impact force of the high-pressure airflow decreases.

[0023] The bottom end of the suction pipe 3 extends out from the bottom of the high-pressure air chamber 2, and the top end of the suction pipe 3 extends out from the top of the high-pressure air chamber 2; a vacuum pump suction machine 8 is connected to the top end of the suction pipe 3; a suction port 6 is provided at the bottom end of the suction pipe 3; a base 4 is connected to the bottom of the suction port 6.

[0024] In this embodiment, the bottom end of the suction pipe 3 is connected to four symmetrically arranged suction ports 6; the base 4 is a conical cylindrical structure, and the base 4 is located between the four suction ports 6. The conical cylindrical base 4 is fixed to the bottom of the hole, making the structure more stable and preventing it from shaking due to the impact of airflow; when it is necessary to clean the loose soil in the hole, the vacuum pump suction machine 8 is turned on, and the loose soil is sucked into the suction pipe 3 through the suction ports 6 and discharged.

[0025] The working principle of the device for dry drilling and enlarging pile heads proposed in this embodiment is as follows:

[0026] The geological conditions of a certain project are as follows: no groundwater was found, all layers of foundation soil are soil, a rotary drilling rig is used to form the hole, the pile diameter is 800mm, it is necessary to enlarge the pile head to improve the bearing capacity, the diameter of the enlarged bottom end is 1200mm, and the side height of the enlarged bottom end is 600mm.

[0027] During construction, a rotary drilling rig is first used to drill a hole to the bottom of the pile. Then, this device is lowered to the bottom of the pile, its position is adjusted, the base 4 is fixed, the air pressure of the air compressor 7 is adjusted, and the regulating valve 1 is gradually raised. The high-pressure airflow impacts the soil on the side of the pile. After a while, the vacuum pump suction machine 8 is turned on. The soil particles are sucked out of the ground through the suction port 6 and the suction pipe 3 using the air pressure difference, thus completing the hole cleaning.

[0028] As the regulating valve 1 is slowly raised, from low to high, more airflow is ejected from the jet hole 5. The downward-spraying airflow impacts the soil on the side of the pile, causing the soil to fall and form a cone, thus completing the base enlargement. Ultimately, the design requirements are met.

[0029] By enlarging the pile head, the end resistance of the pile foundation bearing capacity increased by (0.6). 2 / 0.4 2 =2.25 times, the effect is obvious.

[0030] At the start of construction, a field test is required. First, dig a shallow pile with a diameter of 800mm, place the device inside, turn on the air compressor 7, and set the air pressure level to (0.5~1.0MPa). Then, open the regulating valve 1 and slowly adjust the opening of the jet nozzle 5, observing and recording the progress of soil particles falling. Once a certain amount of soil particles has been collected, turn on the vacuum pump suction machine 8 to suck the soil particles away. At this point, adjust the regulating valve 1 again, which will involve more jet nozzles 5 and increase the area affected by the high-pressure airflow, resulting in more soil particles falling. Repeat this process to gradually form the pile head.

[0031] The above description is a further detailed explanation of the present invention in conjunction with specific preferred embodiments. It should not be considered that the specific embodiments of the present invention are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the present invention, and all such deductions or substitutions should be considered to fall within the scope of patent protection determined by the submitted claims.

Claims

1. A device for dry drilling to enlarge pile heads, characterized in that, The system includes a regulating valve (1), a high-pressure air chamber (2), a suction pipe (3), and a base (4); the side wall of the high-pressure air chamber (2) is provided with multiple air jet holes (5) from top to bottom; an air compressor (7) is connected to the top of the high-pressure air chamber (2); the bottom end of the suction pipe (3) extends out from the bottom of the high-pressure air chamber (2), and the top end of the suction pipe (3) extends out from the top of the high-pressure air chamber (2); a vacuum pump suction machine (8) is connected to the top end of the suction pipe (3); a suction port (6) is provided at the bottom end of the suction pipe (3); the bottom of the suction port (6) is connected to the base (4); the regulating valve (1) is located on the outer wall of the high-pressure air chamber (2) and is used to open and close multiple air jet holes (5).

2. The device for dry drilling and enlarging pile heads according to claim 1, characterized in that, The high-pressure air chamber (2) is a cylindrical structure; the jet holes (5) are evenly distributed on the side wall of the high-pressure air chamber (2).

3. The device for dry drilling and enlarging pile heads according to claim 2, characterized in that, The regulating valve (1) is a cylindrical sleeve structure, and the inner wall of the regulating valve (1) is in a sealed sliding connection with the outer wall of the high-pressure air chamber (2).

4. The device for dry drilling and enlarging pile heads according to claim 3, characterized in that, The top of the regulating valve (1) is connected to a telescopic motor.

5. The device for dry drilling and enlarging pile heads according to claim 1, characterized in that, The bottom end of the suction pipe (3) is connected to four symmetrically arranged suction ports (6); the base (4) is located between the four suction ports (6).

6. The device for dry drilling and enlarging pile heads according to claim 5, characterized in that, The base (4) is a conical cylindrical structure.

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