MJS construction method pile drill bit structure and construction method thereof

Abstract

The invention discloses an MJS construction method pile drill bit structure which comprises a multi-hole drill rod which is vertically lowered until the lower end of the multi-hole drill rod descends to a set position of an area to be reinforced. A spray hole A and a spray hole B are formed in the lower end of the porous drill rod, the spray hole A is located above the spray hole B, and the interior of the porous drill rod is hollow. The slurry pipe is inserted into the porous drill rod, the space, except the slurry pipe, in the porous drill rod is filled with bentonite slurry, and one end of the slurry pipe extends into the slurry box; the sludge discharge valve is mounted at the bottom of the slurry pipe; wherein the bentonite slurry is sprayed into the to-be-reinforced area through the spraying hole B, and the cement slurry is sprayed into the to-be-reinforced area through the mud discharging valve and the spraying hole A in sequence. By designing the double spraying holes and the mud discharging valve, the problems that a traditional MJS construction method is uneven in pile forming and poor in quality are solved, soil body cutting and pile body filling are effectively completed while all-dimensional micro-disturbance high-pressure jet grouting construction is conducted, and a series of problems such as unstable pile body quality and insufficient pile diameter are avoided.

Description

Technical Field

[0001] The present invention relates to the field of MJS construction pile drill bits, and more specifically, to a MJS construction pile multi-hole drill bit structure and a construction method. Background Art

[0002] With the accelerated development of the domestic underground transportation network, urban subway construction has inevitably entered the prosperous areas of the city. Construction in the complex environment of various underground pipelines requires corresponding reinforcement measures. The MJS technology, which uses a unique porous grouting pipe and front-end suction and drainage system, can efficiently manipulate and maintain the pressure level inside the formation, ensure the stability of deep mud discharge operations, and reduce the risk of surface deformation that may be caused during construction.

[0003] During the construction process, due to the complexity of geological conditions, the existing MJS technology, when encountering deep silty clay and water-rich fine sand formations, the single high-pressure jet grouting process is difficult to form a stable pile diameter and quality, resulting in major safety accidents. Summary of the invention

[0004] In order to achieve these purposes and other advantages according to the present invention, a preferred embodiment of the present invention provides a MJS pile drill bit structure, comprising:

[0005] A porous drill rod is lowered vertically until its lower end descends to a set position of the area to be reinforced; a spray hole A and a spray hole B are arranged at the lower end of the porous drill rod, wherein the spray hole A and the spray hole B are arranged at intervals along the length direction of the porous drill hole, the spray hole A is located above the spray hole B, and the porous drill rod is hollow inside;

[0006] A slurry pipe is inserted into the porous drill pipe, the space in the porous drill pipe except the slurry pipe is filled with bentonite slurry, one end of the slurry pipe extends into a mud box, and the mud box contains cement slurry;

[0007] Mud discharge valve, which is installed at the bottom of the slurry pipe;

[0008] The bentonite slurry is sprayed into the area to be reinforced through the spray hole B, and the cement slurry is sprayed into the area to be reinforced through the mud discharge valve and the spray hole A in sequence.

[0009] According to another technical solution of the present invention, the MJS method pile drill bit structure further includes:

[0010] A pressure sensor, which is used to monitor the ground pressure in the area to be reinforced in real time;

[0011] A central control system is connected to the pressure detection device and the mud discharge valve.

[0012] According to another technical solution of the present invention, the spray hole A is located on the side wall of the porous drill rod close to the bottom of the porous drill rod.

[0013] According to another technical solution of the present invention, the pressure sensor is located on the side wall of the porous drill pipe close to the spray hole A, the pressure sensor is located above the spray hole A, and the distance between the pressure sensor and the spray hole A is not less than 100 mm.

[0014] According to another technical solution of the present invention, the mud discharge valve is located on the side wall of the porous drill pipe close to the pressure sensor, and the mud discharge valve is located above the pressure sensor 3, and the distance between the mud discharge valve and the pressure sensor is not less than 500 mm.

[0015] According to another technical solution of the present invention, the spray hole B is located on the side wall of the porous drill pipe close to the mud discharge valve, and the spray hole B is located above the mud discharge valve, and the distance between the spray hole B and the mud discharge valve is not less than 400 mm.

[0016] According to another technical solution of the present invention, the mud discharge valve, the spray hole A, the pressure sensor, and the spray hole B are located on the same straight line, and the straight line is parallel to the axis of the porous drill pipe.

[0017] According to another technical solution of the present invention, the pressure of the slurry pipe is controlled at 25-40 MPa.

[0018] On the other hand, the technical solution of the present invention also provides a construction method of the MJS construction method pile drill bit structure, comprising the following steps:

[0019] The porous drill rod is lowered to the set position of the area to be reinforced, rotated, and gradually moved upward. At the same time, the spray hole B sprays bentonite slurry to the area to be reinforced to cut the soil and lubricate the hole wall, and at the same time, the spray hole A sprays cement slurry to the area to be reinforced to reinforce the soil to form a stable cement-based reinforcement body. Among them, the central control system opens and closes the mud discharge valve according to the underground pressure to force slurry discharge and regulate the disturbance of the construction to the surrounding environment.

[0020] The present invention includes at least the following beneficial effects: the present invention effectively solves the problems of uneven pile formation and poor quality in the traditional MJS method by designing a double spray hole + mud discharge valve structure, and by improving the drill bit structure, while performing all-round micro-disturbance high-pressure jet grouting construction, effectively completes soil cutting and pile filling, avoids a series of problems such as unstable pile quality and insufficient pile diameter, thereby improving the universal applicability of MJS in construction in all strata and ensuring construction quality.

[0021] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the MJS method pile drill bit structure in the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0024] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0025] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0026] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0027] like Figure 1 As shown, a preferred embodiment of the present invention provides a MJS construction method pile drill bit structure, comprising:

[0028] A porous drill rod 1 is lowered vertically until its lower end descends to a set position of the area to be reinforced; a spray hole A2 and a spray hole B5 are arranged at the lower end of the porous drill rod 1, wherein the spray hole A2 and the spray hole B5 are arranged at intervals along the length direction of the porous drill hole, the spray hole A2 is located above the spray hole B5, and the porous drill rod is hollow inside;

[0029] A slurry pipe 6 is inserted into the porous drill pipe 1. The space in the porous drill pipe 1 except the slurry pipe 6 is filled with bentonite slurry. One end of the slurry pipe 6 extends into a mud box 7. The mud box contains cement slurry.

[0030] A mud discharge valve 4, which is installed at the bottom of the slurry pipe 6;

[0031] In the above technical solution, the bentonite slurry is sprayed into the area to be reinforced through the spray hole B to cut the soil and lubricate the hole wall, and the cement slurry is sprayed into the area to be reinforced through the mud discharge valve and the spray hole A in turn to reinforce the soil to form a stable cement-based reinforcement body. While carrying out all-round micro-disturbance high-pressure jet grouting construction, the soil cutting and pile filling are effectively completed, avoiding a series of problems such as unstable pile quality and insufficient pile diameter, thereby improving the universal applicability of MJS in all strata construction and ensuring construction quality.

[0032] Another technical solution of the present invention also includes:

[0033] A pressure sensor 3, which is used to monitor the ground pressure in the area to be reinforced in real time;

[0034] A central control system is connected to the pressure detection device and the mud discharge valve.

[0035] In the above technical solution, when the pressure sensor detects that the ground pressure exceeds the preset value, the central control system controls the mud discharge valve to open and force slurry discharge to avoid a series of safety problems such as subsequent spraying due to excessive ground pressure.

[0036] In another technical solution of the present invention, the spray hole A is located on the side wall of the porous drill rod near the bottom of the porous drill rod.

[0037] The pressure sensor 3 is located on the side wall of the porous drill pipe near the spray hole A. The pressure sensor 3 is located above the spray hole A, and the distance between the pressure sensor 3 and the spray hole A is not less than 100 mm.

[0038] In the above technical solution, a certain distance must be maintained between the pressure sensor 3 and the spray hole A, and this distance cannot be less than 100 mm. After the cement slurry is sprayed out from the spray hole A at high pressure, it will be reflected and rebounded after being blocked by the soil layer. The pressure sensor 3 within the reflection and rebound range can monitor the slurry pressure in real time. If the distance between the two is too small, after the cement slurry is sprayed out from the spray hole A at high pressure, its surrounding environment will be in a negative pressure environment. The pressure sensor is in this negative pressure environment, and it cannot normally contact the rebounded cement slurry on a large scale, which will cause the problem of inaccurate monitoring by the pressure sensor.

[0039] In another technical solution of the present invention, the mud discharge valve 4 is located on the side wall of the porous drill pipe close to the pressure sensor, and the mud discharge valve 4 is located above the pressure sensor 3, and the distance between the mud discharge valve 4 and the pressure sensor 3 is not less than 500 mm.

[0040] The spray hole B is located on the side wall of the porous drill pipe near the mud discharge valve, and the spray hole B is located above the mud discharge valve, and the distance between the spray hole B and the mud discharge valve is not less than 400 mm. This is also to ensure that the mud discharge valve and the spray hole B do not cause errors in the induction of the pressure sensor, and to ensure the monitoring accuracy of the pressure sensor.

[0041] In another technical solution of the present invention, the mud discharge valve, the spray hole A, the pressure sensor, and the spray hole B are located on the same straight line, and the straight line is parallel to the axis of the porous drill pipe.

[0042] In the above technical solution, if the mud discharge valve, the spray hole A, the pressure sensor, and the spray hole B are not in a straight line and are skewed, it will cause inaccurate pressure monitoring by the pressure sensor.

[0043] In another technical solution of the present invention, the pressure of the slurry pipe is controlled at 25-40 MPa.

[0044] On the other hand, the technical solution of the present invention also provides a construction method of an MJS method pile drill bit structure, comprising the following steps:

[0045] The porous drill rod is lowered to the set position of the area to be reinforced, rotated, and gradually moved upward. At the same time, the spray hole B sprays bentonite slurry to the area to be reinforced to cut the soil and lubricate the hole wall, and at the same time, the spray hole A sprays cement slurry to the area to be reinforced to reinforce the soil to form a stable cement-based reinforcement body. Among them, the central control system opens and closes the mud discharge valve according to the underground pressure to force slurry discharge and regulate the disturbance of the construction to the surrounding environment.

[0046] The present invention effectively solves the problems of uneven pile formation and poor quality of the traditional MJS method by designing a double spray hole + mud discharge valve structure. By improving the drill bit structure, the present invention effectively completes the cutting of soil and filling of pile bodies while carrying out all-round micro-disturbance high-pressure jet grouting construction, avoiding a series of problems such as unstable pile quality and insufficient pile diameter, thereby improving the universal applicability of MJS in all strata construction and ensuring construction quality.

[0047] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. An MJS pile drill bit structure, characterized in that: include: A porous drill rod is lowered vertically until its lower end descends to a set position of the area to be reinforced; a spray hole A and a spray hole B are arranged at the lower end of the porous drill rod, wherein the spray hole A and the spray hole B are arranged at intervals along the length direction of the porous drill hole, the spray hole A is located above the spray hole B, and the porous drill rod is hollow inside; A slurry pipe is inserted into the porous drill pipe, the space in the porous drill pipe except the slurry pipe is filled with bentonite slurry, one end of the slurry pipe extends into a mud box, and the mud box contains cement slurry; Mud discharge valve, which is installed at the bottom of the slurry pipe; The bentonite slurry is sprayed into the area to be reinforced through the spray hole B, and the cement slurry is sprayed into the area to be reinforced through the mud discharge valve and the spray hole A in sequence.

2. The MJS pile drill bit structure according to claim 1, characterized in that: Also includes: A pressure sensor, which is used to monitor the ground pressure in the area to be reinforced in real time; A central control system is connected to the pressure detection device and the mud discharge valve.

3. The MJS pile drill bit structure according to claim 1, characterized in that: The spray hole A is located on the side wall of the porous drill rod near the bottom of the porous drill rod.

4. The MJS pile drill bit structure according to claim 2, characterized in that: The pressure sensor is located on the side wall of the porous drill pipe near the spray hole A. The pressure sensor is located above the spray hole A, and the distance between the pressure sensor and the spray hole A is not less than 100 mm.

5. The MJS pile drill bit structure according to claim 4, characterized in that: The mud discharge valve is located on the side wall of the porous drill pipe close to the pressure sensor, and the mud discharge valve is located above the pressure sensor 3, and the distance between the mud discharge valve and the pressure sensor is not less than 500 mm.

6. The MJS pile drill bit structure according to claim 5, characterized in that: The spray hole B is located on the side wall of the porous drill pipe close to the mud discharge valve, and the spray hole B is located above the mud discharge valve. The distance between the spray hole B and the mud discharge valve is not less than 400 mm.

7. The MJS pile drill bit structure according to claim 6, characterized in that: The mud discharge valve, the spray hole A, the pressure sensor, and the spray hole B are located on the same straight line, and the straight line is parallel to the axis of the porous drill rod.

8. The MJS pile drill bit structure according to claim 1, characterized in that: The pressure of the slurry pipe is controlled at 25-40MPa.

9. The construction method of the MJS construction pile drill bit structure according to any one of claims 1 to 7, characterized in that: The following steps are involved: The porous drill rod is lowered to the set position of the area to be reinforced, rotated, and gradually moved upward. At the same time, the spray hole B sprays bentonite slurry to the area to be reinforced to cut the soil and lubricate the hole wall, and at the same time, the spray hole A sprays cement slurry to the area to be reinforced to reinforce the soil to form a stable cement-based reinforcement body. Among them, the central control system opens and closes the mud discharge valve according to the underground pressure to force slurry discharge and regulate the disturbance of the construction to the surrounding environment.

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