A high torque mixing drill and construction method thereof

Abstract

The invention discloses a high torque mixing drilling rig and a construction method thereof, which belongs to the technical field of pile foundation construction, and includes a pile frame, a chassis, a vertical rotary power system, a circumferential rotary power system, a rotary drive, a rotary pressure plate, a drill rod, a drill bit, a chain, a solidified material pumping system, and a high pressure gas supply system; a stopper is provided on the drill rod; the pile frame and the chassis are connected by bolts, the rotary drive is connected to the pile frame by a slide rail, the rotary pressure plate is connected to the vertical rotary power system by a chain, the rotary pressure plate is connected to the drill rod by a flange, the drill rod is connected to the drill bit by a flange, and the solidified material pumping system and the high pressure gas supply system are connected to the drill rod by a high pressure hose. The invention reduces the center of gravity of the drilling rig by placing the power head downward, prevents the drilling rig from tilting forward during the construction process, and achieves the purpose of drilling, lifting the drill and transmitting torque at the same time by only setting one power head, thereby reducing the construction process, improving the construction efficiency, and saving the cost.

Description

Technical Field

[0001] The invention relates to the technical field of pile foundation construction, and in particular to a high-torque mixing drill and a construction method thereof. Background Art

[0002] The construction of high-rise buildings, railways or bridges requires piling, and pile holes need to be drilled for piling. Depending on the geology, pile poles are poured into the holes after drilling, which are called cast-in-place piles, or cement slurry is sprayed into the holes while drilling, and the pile poles are cast in place, which are called mixing piles. Whether it is a cast-in-place pile or a mixing pile, an engineering drill will be used. The core component of the engineering drill is the power head. The main function of the power head is to transmit the torque and speed generated by the power component to the drill tool, so as to achieve continuous drilling and crushing of rocks and gravel by the drill tool. With the vigorous development of the construction industry, the use of engineering drills has become more and more widespread, and higher requirements have been placed on the power head that provides power to the drill tool.

[0003] At present, conventional power heads on the market have complex equipment structures, large volumes, low power, low working efficiency, and inconvenient transportation. In addition, the power head is generally installed on the top of the drilling rig, and gradually lowers with the penetration of the drill rod. The power head is heavy, causing the center of gravity of the drilling rig to tilt forward and move upward, resulting in greater danger during the construction of the drilling rig. In addition, there is also a method of dividing the power head into two parts, one part is responsible for the downward pressure and lifting force at the upper part, and the other part is responsible for providing torque at the lower part, but this structure is relatively complex, the construction process is cumbersome, and the equipment loss is serious. Therefore, in order to solve the above problems, the present invention proposes a high-torque mixing drilling rig and a construction method thereof. Summary of the invention

[0004] In view of the above technical problems existing in the prior art, the present invention proposes a high-torque mixing drill and a construction method thereof, which overcomes the shortcomings of the prior art. By placing the power head downward, the center of gravity of the drill is lowered, preventing the drill from tilting forward during the construction process. By setting only one power head, the purpose of drilling, lifting and transmitting torque can be achieved simultaneously, which reduces the construction process, improves the construction efficiency and saves costs.

[0005] A high-torque mixing drill, characterized in that it includes a pile frame, a chassis, a vertical rotary power system, a circumferential rotary power system, a rotary drive, a rotary pressure plate, a drill rod, a drill bit, a chain, a solidified material pumping system, and a high-pressure gas supply system; the drill rod is provided with a stopper; the rotary drive includes a slide rail, a bracket, a hydraulic motor, a rotary sleeve, a rotary support, a gear, and a key block; the pile frame and the chassis are connected by bolts, the vertical rotary power system and the circumferential rotary power system are both installed on the chassis, the rotary drive is connected to the pile frame through a slide rail, and the rotary pressure plate is connected to the vertical rotary drive through a chain. The rotary force system is connected, the rotary pressure plate is connected to the drill pipe through a flange, the drill pipe is connected to the drill bit through a flange, the solidifying material pumping system and the high-pressure gas supply system are connected to the drill pipe through a high-pressure hose; the slide rail is connected to the bracket through bolts, the hydraulic motor is connected to the bracket through bolts, the hydraulic motor and the gear are driven by bite, the gear is connected to the rotary sleeve through bolts, the gear is connected to the outer ring of the slewing bearing through bolts, the inner ring of the slewing bearing is connected to the bracket through bolts, the rotary sleeve is provided with a keyway, and the key block and the rotary sleeve are connected by a key.

[0006] Preferably, the number of the key slots is at least three, in particular, the number of the key slots is six, and in the cross section, the angle between two adjacent key slots is 60°.

[0007] Preferably, the key block is a rectangular parallelepiped structure, the height of the key block protruding from the rotary sleeve is 4cm-8cm, and the length of the key block is 10cm-15cm.

[0008] Preferably, at least three rows of stoppers are welded on the surface of the drill rod, the three rows of stoppers are evenly distributed along the drill rod, each row of stoppers are distributed in a left-right staggered manner, the depth of each stopper is 3cm-7cm, and the length of each stopper is 15cm-20cm.

[0009] Preferably, there are two hydraulic motors, and the cross-section of the slide rail is a 3 / 5 ring.

[0010] Preferably, the drill rod is composed of an initial drill rod and an external drill rod. If an additional drill rod is to be added, the drill rod is a combination of the initial drill rod and the external drill rod. If no additional drill rod is needed, the drill rod is only the initial drill rod. The diameter range of the initial drill rod and the external drill rod is 80-50mm, and the drill rods are connected by pin connection. The pile frame includes a light pile frame and a load-bearing pile frame. The light pile frame is located above the load-bearing pile frame, and the height of the light pile frame is 1-4 times the height of the load-bearing pile frame.

[0011] A construction method of a high torque mixing drill, characterized in that a high torque mixing drill is used for construction, and the specific construction steps are as follows:

[0012] Step 1: Start the drilling rig, put it in place according to the design requirements, adjust the pile frame and chassis, ensure that the drilling rig is in a horizontal state and the drill rod is in a vertical state, and test run the drilling rig for 5-10 minutes;

[0013] Step 2: Adjust the position of the key block in the slewing drive so that it is located within the initial drill rod light circular track, start the vertical slewing power system, and move the slewing drive upward to the top of the load-bearing pile frame;

[0014] Step 3: Start the annular rotary power system, drive the rotary sleeve to rotate forward through the hydraulic motor, slowly drive the initial drill rod upward through the rotary pressure plate, so that the key block in the rotary drive enters the stopper of the initial drill rod, and then drives the initial drill rod and drill bit to rotate forward, start the vertical rotary power system, so that the rotary drive moves downward, and then drives the initial drill rod and drill bit to move downward, and at the same time start the solidification material pumping system and the high-pressure gas supply system to mix the solidification material into the soil through the drill bit;

[0015] Step 4: When the rotary drive drives the initial drill rod to move downward to the bottom of the bearing pile frame, turn off the circumferential rotary power system, the vertical rotary power system, the solidifying material pumping system, and the high-pressure gas supply system, and repeat steps 3, 4, and the above process of this step until the top of the initial drill rod is 3-5m away from the ground;

[0016] Step 5: If it is necessary to add an external drill rod, turn off the annular rotary power system, the vertical rotary power system, the solidified material pumping system, and the high-pressure gas supply system, release the locking device between the rotary pressure plate and the initial drill rod, lift the rotary pressure plate upward to the set height, connect the upper and lower parts of the external drill rod to the rotary pressure plate and the initial drill rod respectively, and lock them. Similarly, repeat steps 2 to 4 and the above process of this step until all external drill rods are added. When all external drill rods are added or no external drill rods are needed, continue to drive the initial drill rod, drill bit or external drill rod to rotate and move downward through the rotary drive until stirring reaches the set depth;

[0017] Step 6: Adjust the circumferential rotary power system and the vertical rotary power system to make the rotary sleeve rotate in the opposite direction, and slowly drive the initial drill rod upward through the rotary pressure plate, so that the key block in the rotary drive enters the stopper of the initial drill rod, so that the rotary drive drives the initial drill rod, the drill bit or the external drill rod to move upward and rotate in the opposite direction, and the curing agent mixing system and the high-pressure gas supply system continue to pump the curing agent and high-pressure gas into the soil through the drill bit;

[0018] Step 7: If an external drill rod has been added, when the lower end of the first external drill rod is lifted to a height of 0.5-2.0m above the ground, close the annular rotary power system, vertical rotary power system, solidified material pumping system, and high-pressure gas supply system, adjust the position of the key block in the rotary drive so that it is located within the initial drill rod light circular track, move the rotary drive downward to the upper part of the next drill rod, start the annular rotary power system, drive the rotary sleeve to rotate in the opposite direction through the hydraulic motor, and slowly drive the initial drill rod upward through the rotary pressure plate, so that the key block in the rotary drive enters the stop of the next drill rod, and then close the annular rotary power system, release the connection between the first external drill rod and the rotary pressure plate and the next drill rod, Remove the drill rod section, then move the rotary pressure plate downward to connect with the next drill rod section and lock it, open the annular rotary power system and the vertical rotary power system to make the rotary sleeve rotate in the opposite direction, so that the rotary drive drives the initial drill rod, the drill bit or the external drill rod to move upward and rotate in the opposite direction, and at the same time open the solidifying material pumping system and the high-pressure gas supply system, and repeat the above process of this step to remove the next external drill rod until all external drill rods are removed, so that the initial drill rod and the drill bit are retained on the pile frame or no external drill rod is added, and the initial drill rod and the drill bit are continuously lifted, and finally, after the drill bit is completely separated from the soil, the annular rotary power system, the vertical rotary power system, the solidifying material pumping system, and the high-pressure gas supply system are closed;

[0019] Step 8: Level the site near the mixing pile and move the drilling rig to construct the next mixing pile;

[0020] Step 9: Repeat steps 1 to 8 until the construction is completed.

[0021] Preferably, the number of key blocks in the rotary drive can be adjusted according to demand. When the maximum stirring torque is less than 2000 N·m, the number of key blocks is not less than 3, and when the maximum stirring torque is greater than 2000 N·m, the number of key blocks is not less than 6.

[0022] Preferably, the rotary drive drives the initial drill rod to be lifted above the ground. If the drill rod has an inclination angle greater than 5 degrees relative to the vertical direction for no less than 5 times during the continuous 5m lifting process, the original key block should be removed and replaced with a new unworn key block.

[0023] Preferably, the stop surfaces of the initial drill rod and the additional drill rod are evenly sprayed with dispersant or lubricating oil before and during the mixing construction, and the amount of dispersant or lubricating oil on each section of the initial drill rod or the additional drill rod is not less than 1000 mL.

[0024] Beneficial technical effects brought by the present invention:

[0025] By placing the power head downward, the center of gravity of the drilling rig is lowered to prevent the drilling rig from tilting forward during construction. By setting up only one power head, the purpose of drilling, lifting the drill and transmitting torque can be achieved simultaneously, which reduces the construction process, improves construction efficiency and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a structural schematic diagram of a high-torque mixing drill and a drilling rig in a construction method thereof.

[0027] Figure 2 The present invention is a cross-sectional schematic diagram of a high-torque mixing drill and a rotary drive in a construction method thereof.

[0028] Figure 3 The present invention provides a top view of a high-torque mixing drill and a rotary drive in a construction method thereof.

[0029] Figure 4 The present invention is a side view of a high-torque mixing drill and a rotary drive in a construction method thereof.

[0030] Among them, 1-pile frame, 2-chassis, 3-rotary drive, 4-rotary pressure plate, 5-drill rod, 6-drill bit, 7-chain, 8-stop, 31-slide rail, 32-bracket, 33-hydraulic motor, 34-rotary sleeve, 35-rotary support, 36-gear, 37-key block. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0032] like Figures 1 to 4As shown, a high-torque mixing drilling rig is characterized in that it includes a pile frame 1, a chassis 2, a vertical rotary power system, a circumferential rotary power system, a rotary drive 3, a rotary pressure plate 4, a drill rod 5, a drill bit 6, a chain 7, a solidified material pumping system, and a high-pressure gas supply system; the drill rod 5 is provided with a stop 8; the rotary drive 3 includes a slide rail 31, a bracket 32, a hydraulic motor 33, a rotary sleeve 34, a rotary support 35, a gear 36, and a key block 37; the pile frame 1 and the chassis 2 are connected by bolts, the vertical rotary power system and the circumferential rotary power system are both installed on the chassis 2, the rotary drive 3 is connected to the pile frame 1 through a slide rail 31, and the rotary pressure plate 4 is connected to the The vertical rotary power system is connected, the rotary pressure plate 4 is connected to the drill rod 5 through a flange, the drill rod 5 is connected to the drill bit 6 through a flange, and the solidifying material pumping system and the high-pressure gas supply system are connected to the drill rod 5 through a high-pressure hose; the slide rail 31 is connected to the bracket 32 ​​through bolts, the hydraulic motor 33 is connected to the bracket 32 ​​through bolts, the hydraulic motor 33 and the gear 36 are driven by bite, the gear 36 is connected to the rotary sleeve 34 through bolts, the gear 36 is connected to the outer ring of the rotary bearing through bolts, the inner ring of the rotary bearing is connected to the bracket 32 ​​through bolts, the rotary sleeve 34 is provided with a keyway, and the key block 37 is connected to the rotary sleeve 34 through a key.

[0033] Preferably, the number of the key slots is at least three, in particular, the number of the key slots is six, and in the cross section, the angle between two adjacent key slots is 60°.

[0034] Preferably, the key block 37 is a rectangular parallelepiped structure, the height of the key block 37 protruding from the rotating sleeve 34 is 4 cm-8 cm, and the length of the key block 37 is 10 cm-15 cm.

[0035] Preferably, at least three rows of stoppers 8 are welded on the surface of the drill rod 5, and the three rows of stoppers 8 are evenly distributed along the drill rod 5. Each row of stoppers 8 is distributed in a left-right staggered manner, the depth of each stopper 8 is 3cm-7cm, and the length of each stopper 8 is 15cm-20cm.

[0036] Preferably, there are two hydraulic motors 33, and the cross section of the slide rail 31 is a 3 / 5 ring.

[0037] Preferably, the drill rod 5 is composed of an initial drill rod and an external drill rod. If the drill rod 5 is to be added, the drill rod 5 is a combination of the initial drill rod and the external drill rod. If the drill rod 5 is not needed, the drill rod 5 is only the initial drill rod. The diameter range of the initial drill rod and the external drill rod is 80-50mm, and the drill rods 5 are connected by pin connection. The pile frame 1 includes a light pile frame and a load-bearing pile frame. The light pile frame is located above the load-bearing pile frame, and the height of the light pile frame is 1-4 times the height of the load-bearing pile frame.

[0038] A construction method of a high torque mixing drill, characterized in that the high torque mixing drill according to claim 1 is used for construction, and the specific construction steps are as follows:

[0039] Step 1: Start the drilling rig, put it in place according to the design requirements, adjust the pile frame 1 and the chassis 2, ensure that the drilling rig is in a horizontal state and the drill rod 5 is in a vertical state, and test run the drilling rig for 5-10 minutes;

[0040] Step 2: adjust the position of the key block 37 in the rotary drive 3 so that it is located within the initial drill rod light circular track, start the vertical rotary power system, and move the rotary drive 3 upward to the top of the load-bearing pile frame;

[0041] Step 3: Start the annular rotary power system, drive the rotary sleeve 34 to rotate forward through the hydraulic motor 33, slowly drive the initial drill rod upward through the rotary pressure plate 4, so that the key block 37 in the rotary drive 3 enters the stop 8 of the initial drill rod, and then drives the initial drill rod and the drill bit 6 to rotate forward, start the vertical rotary power system, so that the rotary drive 3 moves downward, and then drives the initial drill rod and the drill bit 6 to move downward, and at the same time start the solidification material pumping system and the high-pressure gas supply system to mix the solidification material into the soil through the drill bit 6;

[0042] Step 4: When the rotary drive 3 drives the initial drill rod to move downward to the bottom of the bearing pile frame, the circumferential rotary power system, the vertical rotary power system, the solidifying material pumping system, and the high-pressure gas supply system are turned off, and steps 3, 4, and the above process of this step are repeated until the top of the initial drill rod is 3-5m away from the ground;

[0043] Step 5: If it is necessary to add an external drill rod, turn off the annular rotary power system, the vertical rotary power system, the solidified material pumping system, and the high-pressure gas supply system, release the locking device between the rotary pressure plate 4 and the initial drill rod, lift the rotary pressure plate 4 to the set height, connect the upper and lower parts of the external drill rod to the rotary pressure plate 4 and the initial drill rod respectively, and lock them. Similarly, repeat steps 2 to 4 and the above process of this step until all external drill rods are added. When all external drill rods are added or no external drill rods are needed, continue to drive the initial drill rod, the drill bit 6 or the external drill rod to rotate and move downward through the rotary drive 3 until stirring reaches the set depth;

[0044] Step 6: Adjust the annular rotary power system and the vertical rotary power system to make the rotary sleeve 34 rotate in the opposite direction, and slowly drive the initial drill rod upward through the rotary pressure plate 4, so that the key block 37 in the rotary drive 3 enters the stop 8 of the initial drill rod 5, so that the rotary drive 3 drives the initial drill rod, the drill bit 6 or the external drill rod to move upward and rotate in the opposite direction, and the curing agent mixing system and the high-pressure gas supply system continue to pump the curing agent and high-pressure gas into the soil through the drill bit 6;

[0045] Step 7: If an external drill rod has been added, when the lower end of the first external drill rod section is lifted to a height of 0.5-2.0m above the ground, the annular rotary power system, the vertical rotary power system, the solidified material pumping system, and the high-pressure gas supply system are closed, and the position of the key block 37 in the rotary drive 3 is adjusted so that it is located within the initial drill rod light circular track. After the rotary drive 3 is moved downward to the upper part of the next drill rod section 5, the annular rotary power system is started, and the rotary sleeve 34 is driven to rotate in the opposite direction by the hydraulic motor 33, and the initial drill rod is slowly driven upward by the rotary pressure plate 4, so that the key block 37 in the rotary drive 3 enters the stop 8 of the next drill rod section 5, and then the annular rotary power system is closed, and the upper first external drill rod section and the rotary pressure plate 4 and the next drill rod section 5 are released. After the drill rod 5 is connected, the drill bit 6 is removed, and then the rotary pressure plate 4 moves downward to connect with the next drill rod 5 and locks it. The annular rotary power system and the vertical rotary power system are opened to make the rotary sleeve 34 rotate in the opposite direction, so that the rotary drive 3 drives the initial drill rod, the drill bit 6 or the external drill rod to move upward and rotate in the opposite direction. At the same time, the solidifying material pumping system and the high-pressure gas supply system are opened. The above process of this step is repeated to disassemble the next external drill rod until all the external drill rods are disassembled, so that the initial drill rod and the drill bit 6 are retained on the pile frame 1 or no external drill rod is added. The initial drill rod and the drill bit 6 are continuously lifted. Finally, after the drill bit 6 is completely separated from the soil, the annular rotary power system, the vertical rotary power system, the solidifying material pumping system, and the high-pressure gas supply system are closed.

[0046] Step 8: Level the site near the mixing pile and move the drilling rig to construct the next mixing pile;

[0047] Step 9: Repeat steps 1 to 8 until the construction is completed.

[0048] Preferably, the number of key blocks 37 in the rotary drive 3 can be adjusted according to demand. When the maximum stirring torque is less than 2000 N·m, the number of key blocks 37 is not less than 3, and when the maximum stirring torque is greater than 2000 N·m, the number of key blocks 37 is not less than 6.

[0049] Preferably, the rotary drive 3 drives the initial drill rod to be lifted above the ground. If the drill rod 5 has an inclination angle greater than 5 degrees relative to the vertical direction for no less than 5 times during the continuous 5m lifting process, the original key block 37 should be removed and replaced with a new unworn key block 37.

[0050] Preferably, the surface of the stopper 8 of the initial drill rod and the additional drill rod is evenly sprayed with dispersant or lubricating oil before and during the mixing construction, and the amount of dispersant or lubricating oil on each section of the initial drill rod or the additional drill rod is not less than 1000 mL.

[0051] The present invention discloses a high-torque mixing drill and a construction method thereof. By placing a power head downward, the center of gravity of the drill is lowered to prevent the drill from tilting forward during the construction process. By only setting one power head, the purpose of drilling, lifting the drill and transmitting torque simultaneously is achieved, thereby reducing the construction procedures, improving the construction efficiency and saving the cost.

[0052] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention also fall within the protection scope of the present invention.

[0053] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention also fall within the protection scope of the present invention.

Claims

1. A high torque mixing drill, characterized in that: It includes a pile frame, a chassis, a vertical rotary power system, a circumferential rotary power system, a rotary drive, a rotary pressure plate, a drill rod, a drill bit, a chain, a solidified material pumping system, and a high-pressure gas supply system; the drill rod is provided with a stopper; the rotary drive includes a slide rail, a bracket, a hydraulic motor, a rotary sleeve, a rotary support, a gear, and a key block; the pile frame and the chassis are connected by bolts, the vertical rotary power system and the circumferential rotary power system are both installed on the chassis, the rotary drive is connected to the pile frame through a slide rail, and the rotary pressure plate is connected to the vertical rotary power system through a chain. The rotary pressure plate is connected to the drill pipe through a flange, the drill pipe is connected to the drill bit through a flange, and the solidified material pumping system and the high-pressure gas supply system are connected to the drill pipe through a high-pressure hose; the slide rail is connected to the bracket through bolts, the hydraulic motor is connected to the bracket through bolts, the hydraulic motor and the gear are driven by bite, the gear is connected to the rotary sleeve through bolts, the gear is connected to the outer ring of the rotary bearing through bolts, the inner ring of the rotary bearing is connected to the bracket through bolts, the rotary sleeve is provided with a keyway, and the key block is connected to the rotary sleeve through a key; The drill rod is composed of an initial drill rod and an external drill rod. If an additional drill rod is required, the drill rod is a combination of the initial drill rod and the external drill rod. If no additional drill rod is required, the drill rod is only the initial drill rod. The diameter range of the initial drill rod and the external drill rod is 5cm-8cm, and the drill rods are connected by pin connection. The pile frame includes a light pile frame and a load-bearing pile frame. The light pile frame is located above the load-bearing pile frame, and the height of the light pile frame is 1-4 times the height of the load-bearing pile frame.

2. A high torque mixing drill according to claim 1, characterized in that: The number of the keyways is at least three.

3. A high torque mixing drill according to claim 1, characterized in that: The key block is a rectangular parallelepiped structure, the height of the key block protruding from the rotary sleeve is 4cm-8cm, and the length of the key block is 10cm-15cm.

4. A high torque mixing drill according to claim 1, characterized in that: At least three rows of stoppers are welded on the surface of the drill rod, and the three rows of stoppers are evenly distributed along the drill rod. Each row of stoppers is distributed in a left-right staggered manner. The depth of each stopper is 3cm-7cm, and the length of each stopper is 15cm-20cm.

5. A high torque mixing drill according to claim 1, characterized in that: There are two hydraulic motors, and the cross section of the slide rail is a 3 / 5 ring.

6. A construction method of a high torque mixing drill, characterized in that: The high torque mixing drill described in claim 1 is used for construction, and the specific construction steps are as follows: Step 1: Start the drilling rig, put it in place according to the design requirements, adjust the pile frame and chassis, ensure that the drilling rig is in a horizontal state and the drill rod is in a vertical state, and test run the drilling rig for 5-10 minutes; Step 2: Adjust the position of the key block in the slewing drive so that it is located within the initial drill rod light circular track, start the vertical slewing power system, and move the slewing drive upward to the top of the load-bearing pile frame; Step 3: Start the annular rotary power system, drive the rotary sleeve to rotate forward through the hydraulic motor, slowly drive the initial drill rod upward through the rotary pressure plate, so that the key block in the rotary drive enters the stopper of the initial drill rod, and then drives the initial drill rod and drill bit to rotate forward, start the vertical rotary power system, so that the rotary drive moves downward, and then drives the initial drill rod and drill bit to move downward, and at the same time start the solidification material pumping system and the high-pressure gas supply system to mix the solidification material into the soil through the drill bit; Step 4: When the rotary drive drives the initial drill rod to move downward to the bottom of the bearing pile frame, turn off the circumferential rotary power system, vertical rotary power system, solidifying material pumping system, and high-pressure gas supply system, and repeat steps 3 and 4 until the top of the initial drill rod is 3-5m away from the ground; Step 5: If it is necessary to add an external drill rod, turn off the annular rotary power system, the vertical rotary power system, the solidified material pumping system, and the high-pressure gas supply system, release the locking device between the rotary pressure plate and the initial drill rod, lift the rotary pressure plate upward to the set height, connect the upper and lower parts of the external drill rod to the rotary pressure plate and the initial drill rod respectively, and lock them, repeat steps 2 to 4 and the above process of this step until all external drill rods are added. When all external drill rods are added or no external drill rods are needed, continue to drive the initial drill rod, drill bit or external drill rod to rotate and move downward through the rotary drive until stirring reaches the set depth; Step 6: Adjust the circumferential rotary power system and the vertical rotary power system to make the rotary sleeve rotate in the opposite direction, and slowly drive the initial drill rod upward through the rotary pressure plate, so that the key block in the rotary drive enters the stopper of the initial drill rod, so that the rotary drive drives the initial drill rod, the drill bit or the external drill rod to move upward and rotate in the opposite direction, and the curing agent mixing system and the high-pressure gas supply system continue to pump the curing agent and high-pressure gas into the soil through the drill bit; Step 7: If an external drill rod has been added, when the lower end of the first external drill rod is lifted to a height of 0.5-2.0m above the ground, close the annular rotary power system, the vertical rotary power system, the solidified material pumping system, and the high-pressure gas supply system, adjust the position of the key block in the rotary drive so that it is located in the initial drill rod light circular track, move the rotary drive downward to the upper part of the next drill rod, start the annular rotary power system, drive the rotary sleeve to rotate in the opposite direction through the hydraulic motor, and slowly drive the initial drill rod upward through the rotary pressure plate, so that the key block in the rotary drive enters the stop of the next drill rod, and then close the annular rotary power system, release the connection between the first external drill rod and the rotary pressure plate, and the next drill rod. Then, remove the drill rod section, then move the rotary pressure plate downward to connect with the next drill rod section and lock it, open the annular rotary power system and the vertical rotary power system to make the rotary sleeve rotate in the opposite direction, so that the rotary drive drives the initial drill rod, the drill bit or the external drill rod to move upward and rotate in the opposite direction, and at the same time open the solidifying material pumping system and the high-pressure gas supply system, remove the next external drill rod and repeat the above process of this step until all external drill rods are removed, so that the initial drill rod and the drill bit are retained on the pile frame or no external drill rod is added, and the initial drill rod and the drill bit are continuously lifted, and finally, after the drill bit is completely separated from the soil, the annular rotary power system, the vertical rotary power system, the solidifying material pumping system, and the high-pressure gas supply system are closed; Step 8: Level the site near the mixing pile and move the drilling rig to construct the next mixing pile; Step 9: Repeat steps 1 to 8 until the construction is completed.

7. According to the construction method of a high-torque mixing drilling rig described in claim 6, the number of key blocks in the rotary drive can be adjusted according to demand. When the maximum mixing torque is less than 2000N·m, the number of key blocks is not less than 3, and when the maximum mixing torque is greater than 2000N·m, the number of key blocks is not less than 6.

8. According to the construction method of a high-torque mixing drilling rig described in claim 6, the rotary drive drives the initial drill rod to be lifted above the ground. If the drill rod has an inclination angle greater than 5 degrees relative to the vertical direction for no less than 5 times during the continuous 5m lifting process, the original key block should be removed and replaced with a new, unworn key block.

9. According to the construction method of a high-torque mixing drilling rig described in claim 6, the stop surfaces of the initial drill rod and the additional drill rod are evenly sprayed with dispersant or lubricating oil before and during the mixing construction, and the amount of dispersant or lubricating oil on each section of the initial drill rod or the additional drill rod is not less than 1000 mL.

Images