A rotary digging combined drill rod for reducing negative pressure at the bottom of a pile when drilling is lifted and a construction method of rotary drilling

Abstract

This invention discloses a rotary drilling rig combination drill rod and a rotary drilling construction method for reducing negative pressure at the pile bottom during drilling. It includes a rotary platform and an operating room (including an internal pressure monitor), as well as a drilling lubrication mechanism, a drilling and slag removal mechanism, and a lifting device. The drilling lubrication mechanism includes an inner multi-hole drill bit, an inner drill rod, and an inner drill rod power unit. The inner drill rod power unit is located at the upper end of the inner drill rod and is connected to the lifting device. The drilling and slag removal mechanism includes an outer drill rod bucket, an outer drill rod, and an outer drill rod power unit. The outer drill rod is connected to the lifting device, and the outer drill rod power unit is located at the upper end of the outer drill rod. The outer and inner drill rods are connected in a through-hole configuration, with the inner drill rod placed inside the outer drill rod cavity. This invention reduces the impact of negative pressure at the pile bottom on shield deformation during the construction of cast-in-place piles in subway protection zones, adjacent to existing subway tunnel sections. It minimizes the impact of construction on existing tunnel sections and ensures normal and safe operation within the existing tunnel sections during construction.

Description

Technical Field

[0001] This invention relates to the field of building engineering technology, and in particular to a rotary drilling combination drill rod for reducing negative pressure at the pile bottom during drilling and a rotary drilling construction method. Background Technology

[0002] In accordance with comprehensive urban development planning, the construction of infrastructure such as surface roads and underground roads is based on the conditions of surface transportation and building functions, and the overall planning of underground space functional layout, development scale, construction priorities, pedestrian and vehicular traffic facilities and municipal pipeline facilities. This is to avoid restrictions on the development and construction of underground space after the land is developed. Therefore, urban municipal engineering often faces multi-layered vertical intersecting structures. The construction of other structures over existing subway tunnel sections has also become a common project in urban municipal construction. In particular, the construction environment near the tunnel section is complex and difficult. How to protect the safety of the existing tunnel section to the greatest extent during construction is particularly important. The displacement and deformation of the existing subway shield are very sensitive to operation, and ensuring the safety of subway operation cannot be neglected. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a rotary drilling combined drill rod that reduces negative pressure at the pile bottom during drilling. The drill rod includes a rotary platform and an operating room (containing an underground pressure monitor), as well as a lubrication mechanism, a drilling and slag removal mechanism, and a lifting device. The lubrication mechanism includes an inner multi-hole drill bit, an inner drill rod, and an inner drill rod power unit. The inner drill rod power unit is located at the upper end of the inner drill rod and is connected to the lifting device. The drilling and slag removal mechanism includes an outer drill rod bucket, an outer drill rod, and an outer drill rod power unit. The outer drill rod is connected to the lifting device, and the outer drill rod power unit is located at the upper end of the outer drill rod. The outer drill rod and the inner drill rod are in a through-hole configuration, with the inner drill rod placed inside the outer drill rod cavity.

[0004] Preferably, the inner drill rod is provided with a high-pressure air pipeline, an exhaust pipeline, a spare pipeline, and a pressure sensor circuit pipe. The inner drill rod and the inner multi-hole drill rod bit are bolted together. The lower end of the inner multi-hole drill rod bit is laterally arranged with a high-pressure air jet hole, a pressure detection port, and an anti-backflow tongue hole.

[0005] Preferably, the outer drill rod bucket has a bucket-shaped structure, and the outer drill rod bucket is equipped with a double-headed double-spiral bottom door. Cutting teeth for cutting soil layers are arranged on the outside of the bottom door. A full bucket pressure sensor is arranged on the inner top surface of the outer drill rod bucket to monitor the capacity of the slag and soil in the bucket.

[0006] Preferably, an air compressor is provided on the rotary platform, and the output end of the air compressor is connected to the high-pressure air pipeline inside the inner drill rod.

[0007] Preferably, the lifting device includes a mast, a luffing mechanism, a first winch, a second winch, and a fixed pulley block. The first and second winches are both arranged on the slewing platform. The mast is arranged at the front of the slewing platform. The luffing mechanism is connected to the mast, and the end of the luffing mechanism is fixed on the slewing platform. The fixed pulley block is arranged in the mast slide rail groove for passing steel wire ropes. The first winch pulls the inner drill rod through the first steel wire rope, and the second winch pulls the outer drill rod through the second steel wire rope.

[0008] Preferably, the front section of the mast is provided with a slide rail groove along the height direction, and the inner drill rod power unit and the outer drill rod power unit are both located in the slide rail groove and slide up and down, with the inner drill rod power unit located at the upper end of the outer drill rod power unit.

[0009] A construction method includes the following steps:

[0010] Step 1: Assemble the rotary drilling rig assembly;

[0011] Step 2: Start the rotary drilling rig, adjust the drilling mechanism at the designated location, and lock the rotary platform.

[0012] Step 3: Lower the outer drill pipe bucket using the lifting device and the external drill pipe power unit, drive it to rotate and cut downwards, rotate clockwise to allow drill cuttings to enter the outer drill pipe bucket;

[0013] Step 4: Drill cuttings enter the outer drill pipe bucket. Once the bucket is full, drive the outer drill pipe bucket counterclockwise and close the bottom door of the outer drill pipe bucket.

[0014] Step 5: Drive the lifting device and the inner multi-hole drill rod and drill bit to rotate and descend, and extend the lower end of the outer drill rod and drill bit through the outer drill rod bucket and spray air;

[0015] Step Six: Simultaneously lift the inner and outer drill rods along the mast slide rails to the outside of the hole for slag removal;

[0016] Step 7: Repeat steps 2 through 6 to complete the drilling operation.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] Within the subway protection zone, when constructing cast-in-place piles near existing subway tunnel sections, the impact of negative pressure at the pile bottom generated during construction on the shield deformation should be reduced. The impact of construction on existing tunnel sections should be minimized to ensure normal operation within those sections during construction. Under complex and challenging construction conditions, the impact on existing urban tunnel sections should be reduced to the greatest extent possible, effectively guaranteeing safety, quality, and schedule during construction. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal drill rod of the present invention;

[0022] Figure 3 This is a schematic diagram of the drill bit with internal multi-hole drill rod of the present invention;

[0023] Figure 4 This is a schematic diagram of the elevation of the external drill pipe bucket of the present invention;

[0024] Figure 5 This is a schematic diagram of the bottom surface of the drill bucket of the external drill rod barrel of the present invention;

[0025] Figure 6 This is a schematic diagram of the control system of the present invention;

[0026] Figure 7 This is a flowchart of the construction process of the present invention.

[0027] In the diagram, 1: mast; 2: internal drill rod power unit; 3: mast slide rail; 4: internal drill rod; 5: external drill rod power unit; 6: second wire rope; 7: first wire rope; 8: external drill rod; 9: luffing mechanism; 10: air pipe; 11: operator's cab; 12: second winch; 13: first winch; 14: air compressor; 15: slewing platform; 17: external drill rod bucket; 18: internal multi-hole drill rod drill bit; 19: high-pressure air pipeline; 20: exhaust pipeline; 21: spare pipeline; 22: pressure sensor wiring pipe; 23: anti-backflow tongue; 24: double spiral bottom door; 25: bucket teeth; 26: pressure sensor. Detailed Implementation

[0028] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the embodiments described.

[0029] Reference Figures 1 to 7This invention discloses a rotary drilling combined drill rod for reducing negative pressure at the pile bottom during drilling, comprising a rotary platform 15 and an operating room 11 (including an underground pressure monitor), as well as a lubrication mechanism, a drilling and slag removal mechanism, and a lifting device. The lubrication mechanism includes an inner multi-hole drill bit 18, an inner drill rod 4, and an inner drill rod power unit 2. The inner drill rod power unit is located at the upper end of the inner drill rod and is connected to the lifting device. The drilling and slag removal mechanism includes an outer drill rod bucket 17, an outer drill rod 8, and an outer drill rod power unit 5. The outer drill rod is connected to the lifting device and is located at the upper end of the outer drill rod. The outer drill rod and the inner drill rod are in a through-hole configuration, with the inner drill rod placed inside the outer drill rod cavity. This invention effectively combines the functions of lubrication and slag removal onto a single drill rod through the combination of the inner and outer drill rods, facilitating construction.

[0030] In this invention, the inner drill rod is provided with a high-pressure air pipeline 19, an exhaust pipeline 20, a spare pipeline 21, and a pressure sensor line pipe 22. The inner drill rod and the inner multi-hole drill rod bit are bolted together. The lower end of the inner multi-hole drill rod bit is laterally arranged with a high-pressure air jet hole, a pressure detection port, and an anti-backflow tongue hole. The anti-backflow tongue 23 is a spring device to prevent pipeline blockage. When air is injected, the tongue moves down with the pressure and returns to its original position after the injection is completed.

[0031] In addition, the outer drill rod bucket has a bucket-shaped structure and is equipped with a double-headed double-spiral bottom door 24. The bucket teeth 25 for cutting soil layers are arranged on the outside of the bottom door. A full bucket pressure sensor 26 is arranged on the top surface of the outer drill rod bucket to monitor the capacity of the slag in the bucket. The drilling operation is carried out according to the advance and the feedback from the full bucket pressure sensor to the terminal in the control room.

[0032] Secondly, an air compressor 14 is provided on the rotary platform. The output end of the air compressor is connected to the high-pressure air pipeline inside the inner drill rod through an air pipe 10 to provide the air required by the lubrication mechanism.

[0033] The lifting device of the present invention includes a mast 1, a luffing mechanism 9, a first winch 13, a second winch 12, and a fixed pulley block. The first winch and the second winch are both arranged on a rotating platform. The mast is arranged in the front part of the rotating platform. The luffing mechanism is connected to the mast, and the end of the luffing mechanism is fixed on the rotating platform. The fixed pulley block is arranged in the groove of the mast slide rail 3 for passing steel wire ropes. The first winch pulls the inner drill rod through the first steel wire rope 7, and the second winch pulls the outer drill rod through the second steel wire rope 6. The front section of the mast is provided with a slide rail groove along the height direction. The inner drill rod power device and the outer drill rod power device are both located in the slide rail groove and slide up and down. The inner drill rod power device is located at the upper end of the outer drill rod power device.

[0034] This invention also provides a rotary drilling construction method for reducing the negative pressure at the pile bottom during drilling rig lifting near a subway shield tunnel, comprising the following steps:

[0035] Step 1: Assemble the rotary drilling rig assembly;

[0036] Step 2: Start the rotary drilling rig, adjust the drilling mechanism at the designated location, and lock the rotary platform.

[0037] Step 3: Lower the outer drill pipe bucket using the lifting device and the external drill pipe power unit, drive it to rotate and cut downwards, rotate clockwise to allow drill cuttings to enter the outer drill pipe bucket;

[0038] Step 4: Drill cuttings enter the outer drill pipe bucket. Once the bucket is full, drive the outer drill pipe bucket counterclockwise and close the bottom door of the outer drill pipe bucket.

[0039] Step 5: Drive the lifting device and the inner multi-hole drill rod and drill bit to rotate and descend, and extend the lower end of the outer drill rod and drill bit through the outer drill rod bucket and spray air;

[0040] Step Six: Simultaneously lift the inner and outer drill rods along the mast slide rails to the outside of the hole for slag removal;

[0041] Step 7: Repeat steps 2 through 6 to complete the drilling operation.

[0042] In step four, once the drill cuttings in the drill bucket reach a certain amount, the full-bucket pressure sensor on the top surface of the drill bucket and the drilling progress will send signals back to the terminal in the control room. The control room will then issue a command to stop drilling and close the bottom door of the drill bucket counterclockwise.

[0043] In step five, the inner multi-hole drill bit passes through the outer drill bit bucket and extends beyond its lower end. The outer drill bit bucket has pre-drilled inlet and outlet holes for the inner multi-hole drill bit at the top and bottom. The pressure and radius of the injected air are controlled using a drill rod lateral pressure measuring instrument. A spring-loaded anti-backflow tongue prevents pipe blockage; the tongue descends with pressure during air injection and returns to its original position after injection is complete.

[0044] In step five, the negative pressure at the pile bottom is obtained by inputting soil parameters (internal friction angle, cohesion, compression modulus, water content, etc.) to establish a Plaxis two-dimensional / three-dimensional finite element model of the existing shield tunnel-soil layer. This model simulates the pile head insertion and extraction process during pile driving, and the negative pressure at the pile head contact surface and the resulting deformation of the surrounding structure and soil can be obtained.

[0045] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A rotary auger combination drill rod for reducing negative pressure at the bottom of the pile when the drill is lifted, comprising a rotary platform and an operating chamber, characterized in that: It also includes a drilling lubrication mechanism, a drilling and slag removal mechanism, and a lifting device. The drilling lubrication mechanism includes an inner multi-hole drill bit, an inner drill rod, and an inner drill rod power unit. The inner drill rod power unit is located at the upper end of the inner drill rod, and the inner drill rod is connected to the lifting device. The drilling and slag removal mechanism includes an outer drill rod bucket, an outer drill rod, and an outer drill rod power unit. The outer drill rod is connected to the lifting device, and the outer drill rod power unit is located at the upper end of the outer drill rod. The outer drill rod and the inner drill rod are in a through-hole configuration, and the inner drill rod is placed inside the outer drill rod cavity. The inner drill rod is equipped with a high-pressure air pipeline, an exhaust pipeline, a spare pipeline, and a pressure sensor circuit pipe. The inner drill rod and the inner multi-hole drill rod bit are bolted together. The lower end of the inner multi-hole drill rod bit is laterally arranged with a high-pressure air jet hole, a pressure detection port, and an anti-backflow tongue. The outer drill rod bucket has a bucket-shaped structure and is equipped with a double-headed double-spiral bottom door. Cutting teeth for cutting soil layers are arranged on the outside of the bottom door. A full bucket pressure sensor is arranged on the inner top surface of the outer drill rod bucket to monitor the capacity of the slag and soil in the bucket. An air compressor is installed on the rotary platform, and the output end of the air compressor is connected to the high-pressure air pipeline inside the inner drill pipe.

2. The rotary-digging combined drill pipe for reducing the negative pressure at the bottom of the pile during the extraction of the drill pipe according to claim 1, characterized in that: The lifting device includes a mast, a luffing mechanism, a first winch, a second winch, and a fixed pulley block. The first and second winches are both arranged on the slewing platform. The mast is arranged at the front of the slewing platform. The luffing mechanism is connected to the mast, and the end of the luffing mechanism is fixed to the slewing platform. The fixed pulley block is arranged in the mast slide rail groove for passing steel wire ropes. The first winch pulls the inner drill rod through the first steel wire rope, and the second winch pulls the outer drill rod through the second steel wire rope.

3. The rotary-digging combined drill pipe for reducing the negative pressure at the bottom of the pile during the extraction of the drill pipe, according to claim 2, characterized in that: The front section of the mast is provided with a slide rail groove along the height direction. The inner drill rod power device and the outer drill rod power device are both located in the slide rail groove and slide up and down. The inner drill rod power device is located at the upper end of the outer drill rod power device.

4. A construction method, employing the rotary drilling rig combination as described in any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Assemble the rotary drilling rig assembly; Step 2: Start the rotary drilling rig, adjust the drilling mechanism at the designated location, and lock the rotary platform; Step 3: Lower the outer drill pipe bucket using the lifting device and the external drill pipe power unit, drive it to rotate and cut downwards, rotate clockwise to allow drill cuttings to enter the outer drill pipe bucket; Step 4: Drill cuttings enter the outer drill pipe bucket. Once the bucket is full, drive the outer drill pipe bucket counterclockwise and close the bottom door of the outer drill pipe bucket. Step 5: Drive the lifting device and the inner multi-hole drill rod and drill bit to rotate and descend, and extend the lower end of the outer drill rod and drill bit through the outer drill rod bucket and spray air; Step Six: Simultaneously lift the inner and outer drill rods along the mast slide rails to the outside of the hole for slag removal; Step 7: Repeat steps 2 through 6 to complete the drilling operation.

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