Drilling, sealing and injecting integrated construction method for self-advancing anchor rod

Abstract

The invention discloses a drilling, sealing and injecting integrated construction method for a self-propelled anchor rod. A drilling machine and the self-propelled anchor rod are connected through a rod body connector; a drilling machine is used for providing driving force, meanwhile, a round nut is used for limiting a hexagonal nut, and torque is transmitted to a drill bit; the front-section spiral deslagging channel and the rear-section spiral deslagging channel are used for synchronously discharging slag and chips; the drilling machine is controlled to rotate reversely, the constant-torque pressing piece and the anti-shearing tray are compacted at the hole opening through the hexagonal nut, and the installation operation of the self-advancing anchor rod is completed until the pressing state is achieved; a grouting pump is used for enabling slurry to enter a slurry mixer through a grouting pipe, then the slurry is injected into the deep position of a hole through a grouting channel and a drill bit slurry outlet, in the process, a large threaded section of the middle section is used for conducting dense plugging on a hole gap, the pressure maintaining effect can be achieved, and effective plugging of the crack can be achieved; and when the grouting pressure is suddenly increased, the grouting pump is controlled to stop, the grouting operation is stopped, and then the slurry mixer is blocked. By means of the method, hole drilling, hole sealing and grouting operation can be integrally completed.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel support, and in particular relates to a self-advanced anchor drilling, sealing and injection integrated construction method. Background Art

[0002] Coal is one of the main energy sources in my country, and it has long occupied a large share in my country's primary energy consumption. In the process of coal mining, a series of tunnels need to be excavated. In order to ensure high-yield and efficient production in coal mines, the excavated tunnels need to be reliably and stably supported. Among the numerous tunnels, loose and broken surrounding rock tunnels account for a large proportion due to the influence of mining, geological structure and coal-forming environment. The support is difficult and costly. Under the existing technical conditions, the support method with grouting anchor as the core is mostly used to change the state of the loose and broken surrounding rock of the tunnel to make it a complete structure, so that the surrounding rock can have good supporting and bearing capacity. In the traditional grouting and anchoring construction process, it is often necessary to perform drilling operations first. After the drilling operations are completed, the grouting anchor rods are installed in the boreholes, and then the boreholes are sealed, and finally the grouting operations are performed. This method has a relatively cumbersome construction process and low construction efficiency. At the same time, due to the scattered processes, the quality controllability of drilling, installing anchor rods, sealing boreholes and grouting operations is poor, which not only cannot meet the current needs of efficient tunnel support, but also cannot meet the high-quality support requirements. In order to effectively overcome the above technical problems, it is urgent to provide a self-advanced anchor drilling, sealing and grouting integrated construction method to ensure the safe production of coal mines. Summary of the invention

[0003] In response to the above-mentioned problems of the prior art, the present invention provides an integrated construction method for self-advanced anchor drilling, sealing and grouting. The construction process of this method is simple and convenient. It can complete the drilling, sealing and grouting operations in an integrated manner, which can greatly simplify the construction process of anchor support and significantly improve the accuracy, efficiency and safety of anchor construction.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a self-advanced anchor drilling, sealing and grouting integrated construction method, which adopts a self-advanced anchor; the self-advanced anchor comprises a rod body, a PDC drill bit, an anti-shear tray, a fixed torque pressing plate, a hexagonal nut, a round nut and a slurry mixer; the axis of the rod body has an axially penetrating grouting channel, and its outer surface is a continuous thread structure, and is divided into a first section of corrugated thread segment, a middle section of large thread segment and a final section of corrugated thread segment from the head end to the end; the outer diameter of the first section of corrugated thread segment and the outer diameter of the final section of corrugated thread segment are both less than The outer diameter of the middle large thread section; a front spiral slag discharge channel is formed in the first wave thread section; a rear spiral slag discharge channel is formed in the middle large thread section; the PDC drill bit is installed at the head end of the rod body, and the head end of the PDC drill bit has a drill bit slurry outlet connected to the grouting channel; at the same time, the outer diameter of the PDC drill bit is larger than the outer diameter of the first wave thread section and smaller than the outer diameter of the middle large thread section; the part of the central anchor hole of the anti-shear tray is a tubular structure protruding axially and having a continuously tapered inner and outer diameters, and the inner diameter of the anchor hole is larger than the end section The outer diameter of the corrugated thread segment is smaller than the outer diameter of the middle large thread segment, and the anti-shear tray is slidably mounted on the outside of the last corrugated thread segment through the anchor hole; the fixed torsion pressure plate is a hollow flat-bottomed spherical crown, and a mounting hole is opened at the center of its top; the fixed torsion pressure plate is slidably mounted on the outside of the last corrugated thread segment through the mounting hole, and is closer to the end of the rod body than the anti-shear tray; the hexagonal nut is mounted on the outside of the last corrugated thread segment through threaded matching, and is closer to the end of the rod body than the fixed torsion pressure plate; the outer diameter of the circular nut is larger than the outer diameter of the rod body, The outer diameter of the circular nut is smaller than that of the hexagonal nut. The circular nut is coaxially fixed and welded to the end of the rod body, and its internal thread cavity is smoothly connected to the grouting channel. The main body of the slurry mixer is a rod-shaped structure, and an external thread structure matching the circular nut is arranged on the outer surface. An axially penetrating mixing chamber is arranged at the axis of the slurry mixer, and a cross partition frame for dividing the radial space of the mixing chamber is fixedly installed inside the mixing chamber. The slurry mixer is connected to the inside of the circular nut through threaded fitting, and its head end extends into the grouting channel.

[0005] The construction method includes the following steps:

[0006] Step 1: Select the intended construction location on the rock surface;

[0007] Step 2: prepare a machine rod connector and a drilling rig, wherein an inner hexagonal connecting hole is provided at the front axis of the machine rod connector, and an outer hexagonal connecting head is fixedly connected to the rear axis thereof, and the size of the inner hexagonal connecting hole is adapted to the size of the hexagonal nut, the depth of the inner hexagonal connecting hole is adapted to the length of the last wave thread section, and the size of the outer hexagonal connecting head is adapted to the size of the inner hexagonal mounting hole at the front end of the drilling rig;

[0008] Step 3: Insert the outer hexagonal connector of the machine rod connector into the inner hexagonal mounting hole on the drilling rig, and then put the hexagonal connector from the end of the rod body onto the outside of the hexagonal nut;

[0009] Step 4: Use the drill rig to drive the rod connector to rotate, and synchronously drive the hexagonal nut to rotate in a clockwise direction. When the hexagonal nut reaches the end of the rod body and abuts against the round nut, the round nut locks the hexagonal nut and transmits the torque acting on the hexagonal nut to the rod body and the PDC drill bit, thereby synchronously driving the rod body and the PDC drill bit to rotate at high speed;

[0010] Step 5: Use the high-speed rotating PDC drill bit to perform drilling operations. The high-efficiency cutting performance of the PDC drill bit is used to break up the large coal rock mass in the direction of travel. The slag and debris formed during the drilling process enter the front spiral slag discharge channel. Under the action of the clockwise rotation of the rod body, the slag and debris are taken out of the hole along the front spiral slag discharge channel. As the drilling operation continues, the rod body continues to penetrate deeper into the borehole, and the slag and debris are continuously discharged, thereby achieving preliminary drilling slag and chip removal operations. This process continues until the first wave thread section completely enters the hole.

[0011] Step 6: Reduce the rotation speed of the drill, continue to drive the middle large thread section slowly into the hole, and at the same time, use the slag and debris discharged from the front spiral slag discharge channel to enter the rear spiral slag discharge channel, and continue to be brought out of the hole along the rear spiral channel under the action of rotating the rod body in the clockwise direction, so as to realize the subsequent drilling slag and chip removal operations. After the middle large thread section completely enters the hole, perform step 7;

[0012] Step 7: Control the drilling rig to reverse, so that the machine rod connector synchronously drives the hexagonal nut to rotate in the opposite direction close to the hole. During the reverse rotation of the hexagonal nut, gradually push the fixed torque pressing plate in the direction of the anti-shear tray, and press the head end of the fixed torque pressing plate against the end of the anti-shear tray, and press the head end of the anti-shear tray against the wall surface outside the hole. Continue to apply torque to make the fixed torque pressing plate continue to deform until it reaches the set preload state when it reaches the flattened state, stop applying torque, remove the machine rod connector and the drilling rig from the self-feeding anchor rod, and complete the installation of the self-feeding anchor rod;

[0013] Step 8: Stir the slurry fully to ensure that the uniformity and fluidity of the slurry meet the grouting requirements; connect the pressure gauge to the grouting pipe, and then connect the two ends of the grouting pipe to the slurry outlet of the grouting pump and the end of the slurry mixer respectively;

[0014] Step 9: Use a grouting pump to allow the slurry to enter the mixing chamber of the slurry mixer through the grouting pipe. Under the action of the cross partition frame, the slurry is further mixed evenly in the mixing chamber, and then transported to the drill bit outlet through the grouting channel. Then, it enters the deep hole from the drill bit outlet. In this process, the outer edge of the middle large threaded section that is closely embedded in the hole wall is used to densely seal the hole gap, thereby playing a grouting pressure maintenance role during the grouting process. At the same time, the grouting amount is controlled according to the indication of the pressure gauge. Under the pressure maintenance effect, the continuously entering slurry first fills the entire hole, and then gradually enters the deep cracks to achieve effective sealing of the cracks;

[0015] When the grouting pressure displayed on the pressure gauge suddenly increases, control the grouting pump to stop, stop the grouting operation, remove the grouting pipe, and then seal the end of the slurry mixer.

[0016] Furthermore, in order to facilitate the limiting during the assembly process, the outer fixed sleeve at the end of the slurry mixer is provided with an annular limiting boss.

[0017] Furthermore, in order to reduce the manufacturing cost of the built-in mixer, the slurry mixer is made of nylon and is integrally manufactured by injection molding.

[0018] Furthermore, in order to ensure the overall bearing strength of the anchor rod and to ensure the later support effect, the lengths of the first wave thread section, the middle large thread section and the last wave thread section account for 3 / 5, 1 / 5 and 1 / 5 of the rod length respectively.

[0019] Furthermore, in order to improve the drilling efficiency, the drill bit is a three-wing drill bit.

[0020] Furthermore, in order to achieve stress homogenization and ensure the support effect during long-term use, the edge parts of the anti-shear tray and the anchor hole parts are transitionally connected through a variable diameter section, and 5 to 8 longitudinal ribs are evenly arranged on the circumference of the variable diameter section.

[0021] In the present invention, for the self-advancing anchor rod adopted, the outer diameter of the drill bit fixedly installed at the head end of the rod body is larger than the outer diameter of the first section of the corrugated thread section and smaller than the outer diameter of the middle section of the large thread section. In this way, during the drilling process, the drill bit can be used to form a hole diameter larger than the outer diameter of the first section of the corrugated thread section, thereby effectively reducing the friction and resistance between the first section of the corrugated thread section and the hole wall when advancing, thereby reducing the stress strength of the first section of the corrugated thread section, so that the rod body strength of the first section of the corrugated thread section can be guaranteed. At the same time, the high cutting performance of the drill bit can be fully utilized to quickly crush the coal rock into small particles, and the annular gap between the first section of the corrugated thread section and the hole wall can be used to timely transport the slag and debris to the position of the middle section of the large thread section, thereby improving the slag and chip removal efficiency, effectively preventing the drill from getting stuck due to untimely slag or chip removal, and ensuring the continuity and efficiency of drilling. At the same time, the outer edge surface of the middle large thread section is fully embedded with the hole wall, which has the effect of densely sealing the hole. In this way, during the pumping grouting process, the middle large thread section can be used to effectively seal the slurry to prevent the leakage of slurry, and can play a role in maintaining pressure, which is conducive to the continuous injection of slurry to extend more efficiently to the depth of the surrounding rock cracks, which can significantly improve the filling effect, thereby achieving a more effective reinforcement effect. A front section spiral slag discharge channel is formed in the first section of the corrugated thread section. During the initial drilling process, the front section spiral slag discharge channel can be used to discharge the generated slag and debris in time. In the middle large thread section, a rear section spiral slag discharge channel is formed. During the subsequent drilling process, the rear section spiral slag discharge channel can be used to receive the slag and debris discharged by the front section spiral slag discharge channel and bring it out of the hole mouth, so that the cooperation of the front and rear section spiral slag discharge channels can achieve continuous slag and chip removal operations during the entire drilling process. The drill bit is provided with a grouting port connected to the grouting channel in the rod body, so that subsequent grouting operations can be conveniently performed after the drilling operation is completed. The anchor hole of the anti-shear tray is a continuously tapered tubular structure, and the diameter of the anchor hole is larger than the outer diameter of the last wave thread section, so that the rod body can have a certain swinging free space during construction, so that the angle of the anchor hole can be adjusted to match the bending angle of the rod body by rotating the tray during the drilling process, thereby leaving a certain amount of activity space for the rod body, which can effectively reduce the shear force of the anti-shear tray on the rod body and effectively protect the rod body; at the same time, this structure can evenly spread the stress borne by the anchor hole part to the edges around the anti-shear tray during the support process, and act on the rock surface at the hole mouth, thereby increasing the bearing capacity of the anti-shear tray and achieving stress homogenization. Since the fixed-torsion pressure plate can reach a flattened state under the action of a set pre-tightening pressure, a fixed-torsion pressure plate is provided on one side of the end of the anti-shear tray, so that it can be intuitively judged whether the applied pre-tightening force reaches the set pre-tightening pressure, thereby being able to intuitively judge the state of the pre-tightening force, which is conducive to simplifying the construction process.A circular nut is fixedly welded at the end of the rod body, and the threaded cavity of the circular nut is smoothly connected with the grouting channel of the rod body. At the same time, a hexagonal nut is arranged between the fixed torque pressure plate and the circular nut. On the one hand, the circular nut can be used as a limit block of the hexagonal nut, thereby limiting the retreat stroke of the hexagonal nut, thereby locking the retreat stroke of the hexagonal nut. In this way, when the drilling rig provides a clockwise driving force and drives the hexagonal nut to rotate through the machine rod connecting head, the circular nut can resist and limit the retreat stroke of the hexagonal nut, and can limit the continuous action. The torque acts on the rod body and the drill bit, so that the drilling operation can be realized. In addition, after the anchoring of the rod body is completed, the reverse drilling rig can be used to drive the hexagonal nut to reverse, so as to realize the pre-tightening function of the fixed torque pressing plate and the anti-shear tray by using the hexagonal nut. This design method realizes the dual functions of the forward drilling and reverse pre-tightening of the drilling rig, which not only reduces the operation process of the intermediate links, but also significantly improves the construction efficiency and ensures the stability and reliability of the anchor installation process; on the other hand, the built-in mixer with an external thread structure can be inserted into the inner side of the end of the rod body through thread matching. The interior of the built-in mixer is provided with a mixing chamber, and a separation grid is provided in the mixing chamber. The synergistic effect of the separation grid and the grouting pressure can be fully utilized in the grouting process to crush the large particles again, and the mixed slurry can be mixed twice, so that the slurry is mixed more fully, which greatly increases the permeability of the slurry. In the case of preventing slurry blockage, it is also beneficial to fill the slurry into deeper cracks. The use of the self-advanced anchor rod can realize drilling, hole sealing and hole grouting reinforcement operations in an integrated manner, which not only effectively solves the slurry blocking problem in the surrounding rock grouting reinforcement, but also effectively reduces the shear force of the tray on the rod body. At the same time, it can intuitively judge whether the preload force meets the required requirements, effectively ensure the strength and support effect of the support, and provide reliable technical guarantee for the stable control of the surrounding rock. The front end of the machine rod connector is provided with an inner hexagonal connection hole and the rear end is provided with an outer hexagonal connection head. It is convenient to put the front end of the machine rod connector on the outside of the hexagonal nut through the inner hexagonal connection hole. At the same time, it is convenient to use the outer hexagonal connection head to insert the rear end of the machine rod connector into the inner hexagonal joint at the front end of the drilling rig. In this way, it is convenient to use the machine rod connector to quickly realize a reliable connection between the drilling rig and the rod body. On this basis, as long as the drilling rig is started, the self-advanced anchor rod can be efficiently driven to rotate, and the stability and reliability during the driving process can be effectively ensured. During the initial driving process, the drill is driven to rotate clockwise, and the locking function of the round nut on the hexagonal nut's retreat stroke can be used to transmit torque to the rod body and PDC drill bit, thereby achieving efficient drilling operations. At the end of drilling, the drill is driven to rotate in the opposite direction, and the hexagonal nut can be pushed toward the hole, thereby pressing the fixed torque pressing plate and the anti-shear tray at the hole, and the set preload can be applied. At the same time, during the application of the preload, it is only necessary to observe the state change of the fixed torque pressing plate to determine whether the set preload state has been reached.Therefore, the present invention can realize the drilling and pre-tightening operations only by reversing the drilling rig, which effectively improves the construction efficiency of the support construction. After the first section of the corrugated thread section is completely drilled in, the rotation speed of the drilling rig is reduced to continue to drive the rod body, which can ensure that the force on the rod body is relatively uniform during the drilling process using the middle section of the large thread section, which can avoid the damage to the rod body and obtain a higher quality drilled hole. During the entire drilling process, the real-time slag removal operation of the front section spiral slag removal channel and the rear section spiral slag removal channel can ensure the smooth progress of the drilling process and help improve the drilling efficiency. After the drilling process is completed, the drilling rig and the hexagonal connector are directly removed, and the grouting device is connected to the end of the slurry mixer to directly carry out the grouting operation. During the grouting process, the outer edge of the large threaded section in the middle section is directly used to densely seal the hole gap, which can effectively maintain the pressure. This changes the slurry sealing method in the traditional anchor grouting function, and there is no need to carry out a separate sealing operation process, which simplifies the construction process and further improves the construction efficiency. After the grouting is completed, the end of the slurry mixer can be directly sealed to complete the entire operation.

[0022] The construction process of this method is simple and convenient. It can complete the drilling, sealing and grouting operations in an integrated manner, which greatly simplifies the construction process of anchor support and can significantly improve the accuracy, efficiency and safety of anchor construction. The use of this method for construction can effectively improve the construction efficiency of support construction. At the same time, it can significantly improve the support effect. It has a wide range of applicability and is easy to be used in large-scale applications in various types of engineering support. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the state of construction using a drilling rig and a self-advancing anchor rod in the present invention;

[0024] Figure 2 It is a structural schematic diagram of the self-advancing anchor rod in the present invention;

[0025] Figure 3 It is a structural schematic diagram of the drill bit in the present invention;

[0026] Figure 4 It is a structural schematic diagram of the anti-shear tray in the present invention;

[0027] Figure 5 It is a schematic diagram of the structure of the fixed-torsion pressing sheet in the present invention;

[0028] Figure 6 It is a structural schematic diagram of a slurry mixer in the present invention;

[0029] Figure 7 It is a structural schematic diagram of the machine rod connecting head in the present invention;

[0030] Figure 8 It is a state schematic diagram of the grouting operation in the present invention.

[0031] In the figure: 1. rod body; 1-1. first section of corrugated thread section; 1-2. middle section of large thread section; 1-3. last section of corrugated thread section; 2. PDC drill bit; 2-1. drill bit slurry outlet; 3. anti-shear tray; 3-1. anchor hole; 4. fixed torque pressing plate; 5. hexagonal nut; 6. round nut; 7. slurry mixer; 7-1. cross partition frame; 7-2. annular limit boss; 8. pressure gauge; 9. drilling rig; 10. grouting pump; 11. machine rod connector; 11-1. inner hexagonal connecting hole; 11-2. outer hexagonal connecting head; 12. grouting pipe. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings.

[0033] like Figures 1 to 8As shown, the present invention provides a self-advanced anchor drilling, sealing and grouting integrated construction method, which adopts a self-advanced anchor; the self-advanced anchor comprises a rod body 1, a PDC drill bit 2, an anti-shear tray 3, a fixed torque pressing plate 4, a hexagonal nut 5, a round nut 6 and a slurry mixer 7; the axis of the rod body 1 has an axially through grouting channel, and its outer surface is a continuous thread structure, and is divided into a first section wave thread segment 1-1, a middle section large thread segment 1-2 and a terminal section wave thread segment 1-3 from the head end to the end; the outer diameter of the first section wave thread segment 1-1 and the outer diameter of the terminal section wave thread segment 1-3 are both smaller than the middle section large thread segment The outer diameter of the segment 1-2; a front-stage spiral slag discharge channel is formed in the first wave thread segment 1-1; a rear-stage spiral slag discharge channel is formed in the middle large thread segment 1-2; the PDC drill bit 2 is installed at the head end of the rod body 1, and the head end of the PDC drill bit 2 has a drill bit slurry outlet 2-1 connected to the grouting channel; at the same time, the outer diameter of the PDC drill bit 2 is larger than the outer diameter of the first wave thread segment 1-1 and smaller than the outer diameter of the middle large thread segment 1-2; the part of the central anchor hole 3-1 of the anti-shear tray 3 is a tubular structure protruding axially and having a continuously tapered inner and outer diameters, and the inner diameter of the anchor hole 3-1 ... The outer diameter of the last wave thread section 1-3 is smaller than the outer diameter of the middle large thread section 1-2, and the anti-shear tray 3 is slidably mounted on the outside of the last wave thread section 1-3 through the anchor hole 3-1; the fixed torque pressing plate 4 is a hollow flat-bottomed spherical crown, and a mounting hole is opened at the center of its top; the fixed torque pressing plate 4 is slidably mounted on the outside of the last wave thread section 1-3 through the mounting hole, and it is closer to the end of the rod body 1 than the anti-shear tray 3; the hexagonal nut 5 is mounted on the outside of the last wave thread section 1-3 through thread matching, and it is closer to the end of the rod body 1 than the fixed torque pressing plate 4; the outer diameter of the circular nut 6 The diameter of the slurry mixer 7 is larger than the outer diameter of the rod body 1 and smaller than the outer diameter of the hexagonal nut 5. The circular nut 6 is coaxially fixedly welded to the end of the rod body 1, and its internal thread cavity is smoothly connected with the grouting channel; the main body of the slurry mixer 7 is a rod-shaped structure, and an external thread structure matched with the circular nut 6 is arranged on the outer surface; an axially penetrating mixing chamber is arranged at the axis center of the slurry mixer 7, and a cross partition frame 7-1 for dividing the radial space of the mixing chamber is fixedly installed inside the mixing chamber; the slurry mixer 7 is connected to the inside of the circular nut 6 by threaded fitting, and its head end extends into the grouting channel;

[0034] The construction method includes the following steps:

[0035] Step 1: Select the intended construction location on the rock surface;

[0036] Step 2: Prepare a machine rod connector 11 and a drill 9, wherein an inner hexagonal connecting hole 11-1 is provided at the front axis of the machine rod connector 11, and an outer hexagonal connecting head 11-2 is fixedly connected to the rear axis thereof, and the size of the inner hexagonal connecting hole 11-1 is adapted to the size of the hexagonal nut 5, the depth of the inner hexagonal connecting hole 11-1 is adapted to the length of the last wave thread section 1-3, and the size of the outer hexagonal connecting head 11-2 is adapted to the size of the inner hexagonal mounting hole at the front end of the drill 9;

[0037] Step 3: Insert the outer hexagonal connector 11-2 of the machine rod connector 11 into the inner hexagonal mounting hole on the drilling machine 9, and then insert the hexagonal connector 11 from the end of the rod body 1 onto the outside of the hexagonal nut 5;

[0038] Step 4: Use the drilling rig 9 to drive the rod connector 11 to rotate, and synchronously drive the hexagonal nut 5 to rotate in the clockwise direction. When the hexagonal nut 5 reaches the end of the rod body 1 and abuts against the round nut 6, the round nut 6 performs rear limit locking on the hexagonal nut 5, and transmits the torque acting on the hexagonal nut 5 to the rod body 1 and the PDC drill bit 2, thereby synchronously driving the rod body 1 and the PDC drill bit 2 to rotate at a high speed;

[0039] Step 5: Use the high-speed rotating PDC drill bit 2 to perform drilling operations. The large coal rock mass in the traveling direction is crushed by the efficient cutting performance of the PDC drill bit 2. The slag and debris formed during the drilling process enter the front spiral slag discharge channel. Under the action of the clockwise rotation of the rod body 1, the slag and debris are brought out of the hole along the front spiral slag discharge channel. As the drilling operation continues, the rod body 1 continues to penetrate deeper into the borehole, and the slag and debris are continuously discharged, thereby achieving preliminary drilling slag and chip removal operations. This process continues until the first wave thread section 1-1 completely enters the hole.

[0040] Step 6: Reduce the rotation speed of the drilling machine 9, continue to drive the middle large thread section 1-2 slowly into the hole, and at the same time, use the slag and debris discharged from the front spiral slag discharge channel to enter the rear spiral slag discharge channel, and under the action of the clockwise rotation of the rod body 1, the slag and debris are taken out of the hole along the rear spiral slag discharge channel to achieve subsequent drilling slag and chip removal operations, and execute step 7 after the middle large thread section 1-2 completely enters the hole.

[0041] Step 7: Control the drilling rig 9 to reverse, so that the machine rod connector 11 synchronously drives the hexagonal nut 5 to rotate in the opposite direction toward the hole. During the reverse rotation of the hexagonal nut 5, gradually push the fixed torque pressing plate 4 in the direction of the anti-shear tray 3, and make the head end of the fixed torque pressing plate 4 pressed against the end of the anti-shear tray 3, and make the head end of the anti-shear tray 3 pressed against the wall surface outside the hole. Continue to apply torque to make the fixed torque pressing plate 4 continue to deform until it reaches the set preload state when it reaches the flattened state, stop applying torque, remove the machine rod connector 11 and the drilling rig 9 from the self-feeding anchor rod, and complete the installation of the self-feeding anchor rod.

[0042] Step 8: fully stir the slurry to ensure that the uniformity and fluidity of the slurry meet the grouting requirements; connect the pressure gauge 8 to the grouting pipe 12, and then connect the two ends of the grouting pipe 12 to the slurry outlet of the grouting pump 10 and the end of the slurry mixer 7 respectively;

[0043] Step nine: Use the grouting pump 10 to make the slurry enter the mixing chamber of the slurry mixer 7 through the grouting pipe 12. Under the action of the cross partition frame 7-1, the slurry is further mixed evenly in the mixing chamber, and then transported to the drill bit slurry outlet 2-1 through the grouting channel. Then, it enters the deep hole from the drill bit slurry outlet 2-1. In this process, the outer edge of the middle large threaded section 1-2 that is closely embedded in the hole wall is used to densely seal the hole gap, thereby playing a grouting pressure-maintaining role during the grouting process. At the same time, the grouting amount is controlled according to the indication of the pressure gauge. Under the pressure-maintaining effect, the continuously entering slurry first fills the entire hole, and then gradually enters the deep cracks to achieve effective sealing of the cracks;

[0044] When the grouting pressure displayed on the pressure gauge 8 suddenly increases, the grouting pump 10 is controlled to stop, the grouting operation is stopped, the grouting pipe 12 is removed, and the end of the slurry mixer 7 is blocked.

[0045] In order to facilitate the limiting during the assembly process, the end of the slurry mixer 7 is externally fixed with an annular limiting boss 7-2.

[0046] In order to reduce the manufacturing cost of the built-in mixer, the slurry mixer 7 is made of nylon and is made in one piece by injection molding.

[0047] In order to ensure the overall bearing strength of the anchor rod and to ensure the subsequent support effect, the lengths of the first wave thread section 1-1, the middle large thread section 1-2 and the last wave thread section 1-3 are 3 / 5, 1 / 5 and 1 / 5 of the length of the rod body 1 respectively.

[0048] In order to improve the drilling efficiency, the drill bit 2 is a three-wing drill bit.

[0049] In order to achieve stress homogenization and ensure the supporting effect during long-term use, the edge parts of the anti-shear tray 3 and the anchor hole 3-1 are transitionally connected through a reducing section, and 5 to 8 longitudinal ribs are evenly arranged on the circumference of the reducing section.

[0050] In the present invention, for the self-advancing anchor rod adopted, the outer diameter of the drill bit fixedly installed at the head end of the rod body is larger than the outer diameter of the first section of the corrugated thread section and smaller than the outer diameter of the middle section of the large thread section. In this way, during the drilling process, the drill bit can be used to form a hole diameter larger than the outer diameter of the first section of the corrugated thread section, thereby effectively reducing the friction and resistance between the first section of the corrugated thread section and the hole wall when advancing, thereby reducing the stress strength of the first section of the corrugated thread section, so that the rod body strength of the first section of the corrugated thread section can be guaranteed. At the same time, the high cutting performance of the drill bit can be fully utilized to quickly crush the coal rock into small particles, and the annular gap between the first section of the corrugated thread section and the hole wall can be used to timely transport the slag and debris to the position of the middle section of the large thread section, thereby improving the slag and chip removal efficiency, effectively preventing the drill from getting stuck due to untimely slag or chip removal, and ensuring the continuity and efficiency of drilling. At the same time, the outer edge surface of the middle large thread section is fully embedded with the hole wall, which has the effect of densely sealing the hole. In this way, during the pumping grouting process, the middle large thread section can be used to effectively seal the slurry to prevent the leakage of slurry, and can play a role in maintaining pressure, which is conducive to the continuous injection of slurry to extend more efficiently to the depth of the surrounding rock cracks, which can significantly improve the filling effect, thereby achieving a more effective reinforcement effect. A front section spiral slag discharge channel is formed in the first section of the corrugated thread section. During the initial drilling process, the front section spiral slag discharge channel can be used to discharge the generated slag and debris in time. In the middle large thread section, a rear section spiral slag discharge channel is formed. During the subsequent drilling process, the rear section spiral slag discharge channel can be used to receive the slag and debris discharged by the front section spiral slag discharge channel and bring it out of the hole mouth, so that the cooperation of the front and rear section spiral slag discharge channels can achieve continuous slag and chip removal operations during the entire drilling process. The drill bit is provided with a grouting port connected to the grouting channel in the rod body, so that subsequent grouting operations can be conveniently performed after the drilling operation is completed. The anchor hole of the anti-shear tray is a continuously tapered tubular structure, and the diameter of the anchor hole is larger than the outer diameter of the last wave thread section, so that the rod body can have a certain swinging free space during construction, so that the angle of the anchor hole can be adjusted to match the bending angle of the rod body by rotating the tray during the drilling process, thereby leaving a certain amount of activity space for the rod body, which can effectively reduce the shear force of the anti-shear tray on the rod body and effectively protect the rod body; at the same time, this structure can evenly spread the stress borne by the anchor hole part to the edges around the anti-shear tray during the support process, and act on the rock surface at the hole mouth, thereby increasing the bearing capacity of the anti-shear tray and achieving stress homogenization. Since the fixed-torsion pressure plate can reach a flattened state under the action of a set pre-tightening pressure, a fixed-torsion pressure plate is provided on one side of the end of the anti-shear tray, so that it can be intuitively judged whether the applied pre-tightening force reaches the set pre-tightening pressure, thereby being able to intuitively judge the state of the pre-tightening force, which is conducive to simplifying the construction process.A circular nut is fixedly welded at the end of the rod body, and the threaded cavity of the circular nut is smoothly connected with the grouting channel of the rod body. At the same time, a hexagonal nut is arranged between the fixed torque pressure plate and the circular nut. On the one hand, the circular nut can be used as a limit block of the hexagonal nut, thereby limiting the retreat stroke of the hexagonal nut, thereby locking the retreat stroke of the hexagonal nut. In this way, when the drilling rig provides a clockwise driving force and drives the hexagonal nut to rotate through the machine rod connecting head, the circular nut can resist and limit the retreat stroke of the hexagonal nut, and can limit the continuous action. The torque acts on the rod body and the drill bit, so that the drilling operation can be realized. In addition, after the anchoring of the rod body is completed, the reverse drilling rig can be used to drive the hexagonal nut to reverse, so as to realize the pre-tightening function of the fixed torque pressing plate and the anti-shear tray by using the hexagonal nut. This design method realizes the dual functions of the forward drilling and reverse pre-tightening of the drilling rig, which not only reduces the operation process of the intermediate links, but also significantly improves the construction efficiency and ensures the stability and reliability of the anchor installation process; on the other hand, the built-in mixer with an external thread structure can be inserted into the inner side of the end of the rod body through thread matching. The interior of the built-in mixer is provided with a mixing chamber, and a separation grid is provided in the mixing chamber. The synergistic effect of the separation grid and the grouting pressure can be fully utilized in the grouting process to crush the large particles again, and the mixed slurry can be mixed twice, so that the slurry is mixed more fully, which greatly increases the permeability of the slurry. In the case of preventing slurry blockage, it is also beneficial to fill the slurry into deeper cracks. The use of the self-advanced anchor rod can realize drilling, hole sealing and hole grouting reinforcement operations in an integrated manner, which not only effectively solves the slurry blocking problem in the surrounding rock grouting reinforcement, but also effectively reduces the shear force of the tray on the rod body. At the same time, it can intuitively judge whether the preload force meets the required requirements, effectively ensure the strength and support effect of the support, and provide reliable technical guarantee for the stable control of the surrounding rock. The front end of the machine rod connector is provided with an inner hexagonal connection hole and the rear end is provided with an outer hexagonal connection head. It is convenient to put the front end of the machine rod connector on the outside of the hexagonal nut through the inner hexagonal connection hole. At the same time, it is convenient to use the outer hexagonal connection head to insert the rear end of the machine rod connector into the inner hexagonal joint at the front end of the drilling rig. In this way, it is convenient to use the machine rod connector to quickly realize a reliable connection between the drilling rig and the rod body. On this basis, as long as the drilling rig is started, the self-advanced anchor rod can be efficiently driven to rotate, and the stability and reliability during the driving process can be effectively ensured. During the initial driving process, the drill is driven to rotate clockwise, and the locking function of the round nut on the hexagonal nut's retreat stroke can be used to transmit torque to the rod body and PDC drill bit, thereby achieving efficient drilling operations. At the end of drilling, the drill is driven to rotate in the opposite direction, and the hexagonal nut can be pushed toward the hole, thereby pressing the fixed torque pressing plate and the anti-shear tray at the hole, and the set preload can be applied. At the same time, during the application of the preload, it is only necessary to observe the state change of the fixed torque pressing plate to determine whether the set preload state has been reached.Therefore, the present invention can realize the drilling and pre-tightening operations only by reversing the drilling rig, which effectively improves the construction efficiency of the support construction. After the first section of the corrugated thread section is completely drilled in, the rotation speed of the drilling rig is reduced to continue to drive the rod body, which can ensure that the force on the rod body is relatively uniform during the drilling operation using the middle section of the large thread section, which can avoid the damage to the rod body and obtain a higher quality drill hole. During the entire drilling process, the slag removal operation through the front section spiral slag removal channel and the rear section spiral slag removal channel can ensure the smooth progress of the drilling process and help improve the drilling efficiency. After the drilling process is completed, the drilling rig and the hexagonal connector are directly removed, and the grouting device is connected to the end of the slurry mixer to directly carry out the grouting operation. During the grouting process, the outer edge of the large threaded section in the middle section is directly used to densely seal the hole gap, which can effectively maintain the pressure. This changes the slurry sealing method in the traditional anchor grouting function, and there is no need to carry out a separate sealing operation process, which simplifies the construction process and further improves the construction efficiency. After the grouting is completed, the end of the slurry mixer can be directly sealed to complete the entire operation.

[0051] The construction process of this method is simple and convenient. It can complete the drilling, sealing and grouting operations in an integrated manner, which greatly simplifies the construction process of anchor support and can significantly improve the accuracy, efficiency and safety of anchor construction. The use of this method for construction can effectively improve the construction efficiency of support construction. At the same time, it can significantly improve the support effect. It has a wide range of applicability and is easy to be used in large-scale applications in various types of engineering support.

Claims

1. A self-advancing anchor rod drilling, sealing and grouting integrated construction method, using a self-advancing anchor rod; the self-advancing anchor rod comprises a rod body (1), a PDC drill bit (2), an anti-shear tray (3), a fixed torque pressing plate (4), a hexagonal nut (5), a round nut (6) and a slurry mixer (7); the axis of the rod body (1) has an axially through-going grouting channel, the outer surface of which is a continuous thread structure, and is divided into a first wave thread section (1-1), a middle large thread section (1-2) and a terminal wave thread section (1-3) from the head end to the tail end; the outer diameter of the first wave thread section (1-1) and the outer diameter of the terminal wave thread section (1-3) are both smaller than the outer diameter of the middle large thread section (1- 2); a front-stage spiral slag discharge channel is formed in the first-stage wave thread section (1-1); and a rear-stage spiral slag discharge channel is formed in the middle-stage large thread section (1-2); the PDC drill bit (2) is installed at the head end of the rod body (1), and the head end of the PDC drill bit (2) has a drill bit grouting port (2-1) connected to the grouting channel; at the same time, the outer diameter of the PDC drill bit (2) is larger than the outer diameter of the first-stage wave thread section (1-1) and smaller than the outer diameter of the middle-stage large thread section (1-2); the portion of the central anchor hole (3-1) of the anti-shear tray (3) is a tubular structure protruding in the axial direction and having a continuously tapered inner and outer diameters, and the inner diameter of the anchor hole (3-1) is larger than the outer diameter of the end portion. The outer diameter of the first wave thread section (1-3) is smaller than the outer diameter of the middle large thread section (1-2); the anti-shear tray (3) is slidably mounted on the outside of the last wave thread section (1-3) through the anchor hole (3-1); the fixed torque pressing plate (4) is in the shape of a hollow flat-bottomed spherical crown, and a mounting hole is provided at the center of its top; the fixed torque pressing plate (4) is slidably mounted on the outside of the last wave thread section (1-3) through the mounting hole, and is closer to the end of the rod body (1) than the anti-shear tray (3); the hexagonal nut (5) is mounted on the outside of the last wave thread section (1-3) through threaded matching, and is closer to the end of the rod body (1) than the fixed torque pressing plate (4); the circular nut ( The outer diameter of the circular nut (6) is larger than the outer diameter of the rod body (1) and smaller than the outer diameter of the hexagonal nut (5); the circular nut (6) is coaxially fixedly welded to the end of the rod body (1), and its internal thread cavity is smoothly connected to the grouting channel; the main body of the slurry mixer (7) is a rod-shaped structure, and an external thread structure matching the circular nut (6) is arranged on the outer surface; an axially penetrating mixing chamber is arranged at the axis of the slurry mixer (7), and a cross partition frame (7-1) for dividing the radial space of the mixing chamber is fixedly installed inside the mixing chamber; the slurry mixer (7) is connected to the inside of the circular nut (6) by threaded fitting, and its head end extends into the grouting channel; It is characterized in that The following steps are involved: Step 1: Select the intended construction location on the rock surface; Step 2: prepare a machine rod connector (11) and a drilling machine (9), wherein the front end axis of the machine rod connector (11) is provided with an inner hexagonal connecting hole (11-1), and the rear end axis thereof is fixedly connected with an outer hexagonal connecting head (11-2), and the size of the inner hexagonal connecting hole (11-1) is adapted to the size of the hexagonal nut (5), the depth of the inner hexagonal connecting hole (11-1) is adapted to the length of the last wave thread section (1-3), and the size of the outer hexagonal connecting head (11-2) is adapted to the size of the inner hexagonal mounting hole at the front end of the drilling machine (9); Step 3: Insert the outer hexagonal connector (11-2) of the machine rod connector (11) into the inner hexagonal mounting hole on the drilling machine (9), and then insert the hexagonal connector (11) from the end of the rod body (1) onto the outside of the hexagonal nut (5); Step 4: Use the drilling rig (9) to drive the rod connector (11) to rotate, and synchronously drive the hexagonal nut (5) to rotate in the clockwise direction. When the hexagonal nut (5) reaches the end of the rod body (1) and contacts the round nut (6), the round nut (6) performs rear limit locking on the hexagonal nut (5), and transmits the torque acting on the hexagonal nut (5) to the rod body (1) and the PDC drill bit (2), thereby synchronously driving the rod body (1) and the PDC drill bit (2) to rotate at a high speed. Step 5: Use the high-speed rotating PDC drill bit (2) to perform drilling operations. The high-efficiency cutting performance of the PDC drill bit (2) is used to break up the large coal rock mass in the direction of travel. The slag and debris formed during the drilling process enter the front spiral slag discharge channel. Under the action of the clockwise rotation of the rod body (1), the slag and debris are brought out of the hole along the front spiral slag discharge channel. As the drilling operation continues, the rod body (1) continues to penetrate deeper into the borehole, and the slag and debris are continuously discharged, thereby achieving preliminary drilling slag and chip removal operations. This process continues until the first wave thread section (1-1) completely enters the hole. Step 6: Reduce the rotation speed of the drilling machine (9), continue to drive the middle large thread section (1-2) slowly into the hole, and at the same time, use the slag and debris discharged from the front spiral slag discharge channel to enter the rear spiral slag discharge channel, and under the action of rotating the rod body (1) in the clockwise direction, continue to be brought out of the hole along the rear spiral channel, so as to achieve subsequent drilling slag and chip removal operations. After the middle large thread section (1-2) completely enters the hole, execute step 7; Step 7: Control the drilling rig (9) to reverse, so that the machine rod connector (11) synchronously drives the hexagonal nut (5) to rotate in the opposite direction toward the hole opening. During the reverse rotation of the hexagonal nut (5), the fixed torque pressing plate (4) is gradually pushed in the direction of the anti-shear tray (3), and the head end of the fixed torque pressing plate (4) is pressed against the end of the anti-shear tray (3), and the head end of the anti-shear tray (3) is pressed against the wall surface outside the hole opening. The torque is continuously applied to cause the fixed torque pressing plate (4) to continue to deform until the set preload state is reached when the flattening state is reached. Stop applying the torque, remove the machine rod connector (11) and the drilling rig (9) from the self-feeding anchor rod, and complete the installation operation of the self-feeding anchor rod. Step 8: Fully stir the slurry to ensure that the uniformity and fluidity of the slurry meet the grouting requirements; connect the pressure gauge (8) to the grouting pipe (12), and then connect the two ends of the grouting pipe (12) to the slurry outlet of the grouting pump (10) and the end of the slurry mixer (7) respectively; Step nine: using a grouting pump (10) to allow the slurry to enter the mixing chamber of the slurry mixer (7) through the grouting pipe (12). Under the action of the cross partition frame (7-1), the slurry is further mixed evenly in the mixing chamber and then transported to the drill bit slurry outlet (2-1) through the grouting channel. Then, the slurry enters the deep hole from the drill bit slurry outlet (2-1). In this process, the outer edge of the middle large threaded section (1-2) that is closely embedded in the hole wall is used to tightly seal the hole gap, thereby playing a grouting pressure-maintaining role during the grouting process. At the same time, the grouting amount is controlled according to the indication of the pressure gauge (8). Under the pressure-maintaining effect, the continuously entering slurry first fills the entire hole, and then gradually enters the deep cracks, thereby achieving effective sealing of the cracks. When the grouting pressure displayed on the pressure gauge (8) suddenly increases, the grouting pump (10) is controlled to stop, the grouting operation is stopped, the grouting pipe (12) is removed, and the end of the slurry mixer (7) is blocked.

2. A self-advanced anchor drilling and sealing and injection integrated construction method according to claim 1, characterized in that: The outer end of the slurry mixer (7) is fixedly sleeved with an annular limiting boss (7-2).

3. The self-advanced anchor drilling and sealing and injection integrated construction method according to claim 1 is characterized in that: The slurry mixer (7) is made of nylon and is integrally manufactured by injection molding.

4. A self-advanced anchor drilling and sealing and injection integrated construction method according to claim 1 or 2, characterized in that: The lengths of the first wave thread section (1-1), the middle large thread section (1-2) and the last wave thread section (1-3) account for 3 / 5, 1 / 5 and 1 / 5 of the length of the rod body (1) respectively.

5. The self-advanced anchor drilling and sealing and injection integrated construction method according to claim 3 is characterized in that: The drill bit (2) is a three-wing drill bit.

6. A self-advanced anchor drilling and sealing and injection integrated construction method according to claim 4, characterized in that: The edge portions of the anti-shear tray (3) and the anchor hole (3-1) thereof are transitionally connected via a diameter-reducing section, and 5 to 8 longitudinal ribs are evenly arranged in the circumferential direction of the diameter-reducing section.

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