Prestressed anchor cable with controllable elongation, supporting equipment and supporting method

Abstract

The invention discloses an elongation-controllable pre-stressed anchor cable, supporting equipment and a supporting method.The elongation-controllable pre-stressed anchor cable comprises a screw rod, a tray, a taper sleeve, a connecting pipe and a shaft sleeve, the upper end of the connecting pipe is connected with a connecting sleeve II, the lower end of the connecting pipe is connected with a connecting sleeve I, the connecting sleeve I is connected with the screw rod, the tray is installed on the screw rod, and a taper hole is formed in the lower end of the connecting pipe; the upper end of the shaft sleeve is provided with a counter bore used for installing a steel strand, and the lower end of the shaft sleeve penetrates through the connecting sleeve II and the connecting pipe and then is connected with the taper sleeve. The screw rod, the connecting sleeve I, the connecting pipe and the connecting sleeve II are connected into a whole, the taper sleeve and the shaft sleeve are connected into a whole, and when rock mass changes, the taper sleeve and the shaft sleeve slide along the inner wall of the connecting pipe together. When large deformation of surrounding rock occurs, the length of the anchor cable is automatically prolonged through a sliding mechanism between the shaft sleeve and the connecting pipe, the anchor cable is prevented from being broken due to excessive stretching, and the problem that the anchor cable is broken due to large deformation of the surrounding rock of a roadway can be effectively solved.

Description

Technical Field

[0001] The invention relates to a prestressed anchor cable with controllable elongation, supporting equipment and supporting method, and belongs to the field of coal mine tunnel support. Background Art

[0002] In coal mining, the stability of the tunnel is the key to ensuring production safety. Anchor cables are widely used in support under complex geological conditions because they can effectively control tunnel deformation and improve support effect and safety.

[0003] In deep mining environments, the nonlinear large deformation characteristics of the surrounding rock make it difficult for traditional anchor cables to meet support requirements due to insufficient elongation. The anchor cables may break, resulting in support failure, which increases construction risks and costs. In addition, traditional anchor cables are prone to breakage or relaxation when subjected to surrounding rock deformation pressure for a long time because they cannot maintain stable prestress. During installation and adjustment, it often takes a long time and complex procedures. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a prestressed anchor cable with controllable elongation, a supporting device and a supporting method, which can effectively deal with the problem of anchor cable breaking due to large deformation of tunnel surrounding rock.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts a controllable elongation prestressed anchor cable, comprising a screw, a tray, a cone sleeve, a connecting pipe and a sleeve, wherein the upper end of the connecting pipe is connected to the connecting sleeve II, the lower end of the connecting pipe is connected to the connecting sleeve I, the connecting sleeve I is connected to the screw, the tray is installed on the screw, the lower end of the connecting pipe is provided with a cone hole, a cone sleeve is installed in the cone hole, the upper end of the sleeve is provided with a countersunk hole for installing a steel strand, and the lower end of the sleeve is connected to the cone sleeve after passing through the connecting sleeve II and the connecting pipe;

[0006] The screw, connecting sleeve I, connecting pipe and connecting sleeve II are connected as a whole, and the cone sleeve and shaft sleeve are connected as a whole. When the rock mass changes, the cone sleeve and the shaft sleeve slide together along the inner wall of the connecting pipe.

[0007] As an improvement, the upper and lower ends of the connecting pipe are respectively processed with external threads and the lower end is provided with the tapered hole, the taper of the tapered hole is consistent with the taper of the outer circle of the tapered sleeve, and the inner hole of the tapered sleeve is a threaded hole;

[0008] The lower end of the sleeve is processed with an external thread, and the lower end of the sleeve passes through the connecting sleeve II and the connecting pipe and is connected to the internal threaded hole of the tapered sleeve; the upper and lower ends of the connecting sleeve I are respectively processed with threaded holes, the upper threaded hole is connected to the connecting pipe, and the lower threaded hole is connected to the screw.

[0009] As an improvement, the lower end of the screw rod is connected to a ball nut, and one end of the internal thread hole of the ball nut is connected to a plunger.

[0010] As an improvement, the maximum elongation is the difference between the length of the connecting pipe and the length of the vertical section of the tapered sleeve.

[0011] In the second aspect of the present invention, there is also provided a support device for a large-deformation roadway, including:

[0012] The controllable elongation prestressed anchor cable as described above;

[0013] A stirrer, including a drill rig connecting sleeve, a triangular plate, and a nut connector. The upper end of the drill rig connecting sleeve is connected to the nut connector, the nut connector is connected to the ball nut, the lower end of the drill rig connecting sleeve is connected to the drill rig, the triangular plate is installed on the drill rig connecting sleeve. When the stirrer works, it drives the ball nut to rotate, and at the same time also drives the connecting sleeve Ⅰ, the connecting pipe, the shaft sleeve, the tapered sleeve, and the steel strand to rotate;

[0014] A prestress installer for tensioning the steel strand.

[0015] As an improvement, the stirrer includes:

[0016] A drill rig connecting sleeve, the outer circle of its upper end is provided with threads, and the lower end is a regular polygon structure for connecting the drill rig;

[0017] A triangular plate, with a rotating seat installed in the middle. Guide rod sleeves are respectively provided at the three corners of the triangular plate to form a triangular support structure. The triangular plate, the rotating seat, and the guide rod sleeves form an integral body;

[0018] A nut connector, with an inner hole provided at its upper end for installing the ball nut, and a threaded hole at its lower end for threaded connection with the drill rig connecting sleeve. The nut connector is installed in the hole of the rotating seat, and the outer circle of the nut connector and the inner hole of the rotating seat cooperate to form a shaft and hole for installing a bearing.

[0019] As an improvement, a bushing is installed in the guide rod sleeve, a push rod is installed in the guide rod sleeve and the bushing, and a spring is installed on the push rod for forming a three-point elastic support for the support.

[0020] As an improvement, the prestress installer includes an outer cylinder, a piston, a housing, and a spherical pad;

[0021] The upper end of the outer cylinder is connected to the housing, and the lower end is connected to the cover plate. The inner cavity of the outer cylinder is a cylinder, and a return spring and a piston are installed for making the piston perform reciprocating linear motion. A hole for the inner sleeve to pass through is provided in the piston. One end of the inner sleeve is connected to the screw rod in the controllable elongation prestressed anchor cable, and the other end is used to abut against the end face of the piston. When the piston moves, it drives the inner sleeve to move together;

[0022] The upper and lower end faces of the spherical pad are both spherical surfaces, which are respectively in contact with the lower spherical surface of the tray in the prestressed anchor cable with controllable elongation and the upper spherical surface of the outer shell.

[0023] As an improvement, the prestressed installer further includes a gear I and a gear II. The gear I is an external gear with a polygonal inner hole at the upper end and a through inner hole at the lower end. The gear II is an external gear and meshes with the gear I. The upper inner hole of the gear II is a cylinder for installing a small shaft, and the lower end is for installing a ratchet wrench.

[0024] In the third aspect of the present invention, there is also provided a support method for the support equipment for large-deformation roadways, including the following steps:

[0025] S1. Drilling holes with a drill;

[0026] S2. Put the anchoring agent into the bolt hole, and push one end of the prestressed anchor cable with controllable elongation against the anchoring agent and push it into the bolt hole;

[0027] S3. Place the tray;

[0028] S4. Assemble the ball head nut onto the screw rod at the lower end of the prestressed anchor cable with controllable elongation;

[0029] S5. Insert the ball head nut into the agitator;

[0030] S6. Start the bolt drill. The agitator rotates to drive the ball head nut and the prestressed anchor cable with controllable elongation to rotate. At this time, the anchoring agent also rotates synchronously and continuously collides with the rock wall to generate friction, and pierces the outer packaging of the anchoring agent. The anchoring agent flows out of the packaging, and the agitator continuously rotates to stir the anchoring agent;

[0031] S7. Wait for a period of time for the anchoring agent to solidify, and the steel strand rod body solidifies with the surrounding rock;

[0032] S8. Start the drill. The agitator rotates to drive the ball head nut to rotate. When the torque transmitted by the drill is greater than the resistance of the plunger in the ball head nut, the plunger is automatically pushed out, and the ball head nut moves along the axis of the screw rod until it reaches the concave socket of the tray, and the screw rod is locked to achieve rapid installation;

[0033] S9. Tighten again. Connect the screw rod at the lower end of the ball head nut to the prestressed installer. The hydraulic oil pump starts to inject oil into the prestressed installer. The high-pressure oil enters the cavity of the cylinder body from the oil inlet hole. Since the oil pressure at the upper end of the piston is greater than the spring force at the lower end, the oil pressure pushes the piston to move downward along the inner wall of the outer cylinder, and the inner sleeve moves downward synchronously with the piston, and the steel strand also moves downward for tensile movement to achieve prestress tensioning.

[0034] Compared with the prior art, when large deformation occurs in the surrounding rock, the present invention realizes the automatic elongation of the anchor cable length through the sliding mechanism between the bushing and the connecting pipe, preventing the anchor cable from breaking due to excessive stretching, and can effectively cope with the problem of anchor cable breakage caused by large deformation of the roadway surrounding rock; by connecting the ball head nut with the agitator, the mixing of the anchoring agent and rapid support can be realized; the prestressed installer can be used to perform secondary tensioning on the anchor cable, and at the same time, the prestress can be adjusted by changing the specifications of the prestressed installer to adapt to different support requirements and geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a schematic structural diagram of the controllable elongation prestressed anchor cable of the present invention;

[0037] Figure 2 It is a three-dimensional structural diagram of the agitator of the present invention;

[0038] Figure 3 It is a sectional view of the agitator of the present invention;

[0039] Figure 4 It is a three-dimensional structural diagram of the prestressed installer of the present invention;

[0040] Figure 5 It is a sectional view of the prestressed installer of the present invention;

[0041] Figure 6 It is a schematic diagram of the maximum elongation of the controllable elongation prestressed anchor cable of the present invention;

[0042] Figure 7 It is a working principle diagram of the agitator of the present invention;

[0043] Figure 8 It is a working principle diagram of the prestressed installer of the present invention;

[0044] In the figure: 100, controllable elongation prestressed anchor cable, 1001, plunger, 1002, ball head nut, 1003, screw rod, 1004, tray, 1005, connecting sleeve I, 1006, tapered sleeve, 1007, connecting pipe, 1008, bushing, 1009, connecting sleeve II, 1010, steel strand;

[0045] 200. Agitator, 2001. Drill rig connecting sleeve, 2002. Triangular plate, 2003. Rotating seat, 2004. Bearing, 2005. Retaining ring Ⅰ, 2006. Nut connector, 2007. Spring, 2008. Ejector rod, 2009. Guide rod sleeve, 2010. Bushing;

[0046] 300. Prestressed installer, 3001. Ratchet wrench, 3002. Cover plate, 3003. Return spring, 3004. Gear Ⅱ, 3005. Outer cylinder, 3006. Piston, 3007. Inner sleeve, 3008. Small shaft, 3009. Outer shell, 3010. Gear Ⅰ, 3011. Spherical washer. Detailed implementation manners

[0047] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the technical solutions of this application will be described in detail below through the accompanying drawings and specific embodiments. It should be understood that the specific features in the embodiments of this application and the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. Without conflict, the technical features in the embodiments of this application and the embodiments can be combined with each other.

[0048] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation on the protected content of the present invention.

[0049] As Figure 1 shown, a controllable elongation prestressed anchor cable includes a screw rod 1003, a tray 1004, a tapered sleeve 1006, a connecting pipe 1007 and a bushing 1008. The upper end of the connecting pipe 1007 is connected to a connecting sleeve Ⅱ 1009, and the lower end of the connecting pipe 1007 is connected to a connecting sleeve Ⅰ 1005. The connecting sleeve Ⅰ 1005 is connected to the screw rod 1003. The tray 1004 is installed on the screw rod 1003. A tapered hole is provided at the lower end of the connecting pipe 1007, and a tapered sleeve 1006 is installed in the tapered hole. A counterbore for installing a steel strand 1010 is provided at the upper end of the bushing 1008. The lower end of the bushing 1008 passes through the connecting sleeve II 1009 and the connecting pipe 1007 and then is connected to the tapered sleeve 1006;

[0050] The screw rod 1003, the connecting sleeve Ⅰ 1005, the connecting pipe 1007 and the connecting sleeve II 1009 are connected as a whole, and the tapered sleeve 1006 and the bushing 1008 are connected as a whole. When the rock mass changes, the tapered sleeve 1006 and the bushing 1008 slide along the inner wall of the connecting pipe 1007 together.

[0051] As one of the embodiments, as Figure 1 shown, external threads are respectively machined at the upper and lower ends of the connecting pipe 1007, and the tapered hole is provided at the lower end. The taper of the tapered hole is consistent with the taper of the outer circle of the tapered sleeve 1006, and the inner hole of the tapered sleeve 1006 is a threaded hole;

[0052] External threads are machined at the lower end of the bushing 1008. The lower end of the bushing 1008 passes through the connecting sleeve II 1009 and the connecting pipe 1007 and is connected to the internal threaded hole of the tapered sleeve 1006; threaded holes are respectively machined at the upper and lower ends of the connecting sleeve I 1005. The upper threaded hole is connected to the connecting pipe 1007, and the lower threaded hole is connected to the screw rod 1003.

[0053] As one of the embodiments, as Figure 1 shown, the lower end of the screw rod 1003 is connected to the ball head nut 1002, and one end of the internal threaded hole of the ball head nut 1002 is connected to the plunger 1001.

[0054] As one of the embodiments, as Figure 1 shown, the maximum elongation of the controllable elongation prestressed anchor cable 100 is the difference between the length of the connecting pipe 1007 and the vertical section length of the tapered sleeve 1006, that is, the length of the L section in Figure 1 . The I-I section is located above the vertical section of the tapered sleeve, and the II-II section is located at the upper end of the connecting pipe 1007.

[0055] It should be noted that the working principle of the controllable elongation prestressed anchor cable 100 is as follows:

[0056] The controllable elongation prestressed anchor cable 100 is seamlessly connected by the screw rod 1003, the connecting sleeve I 1005, the tapered sleeve 1006, the connecting pipe 1007, the bushing 1008, the connecting sleeve II 1009, and the steel strand 1010. Through the combination formed with the ball head nut 1002 and the high-strength prestressed tray 1004 after the rapid support is completed, the deformation of the surrounding rock is effectively controlled. When the tension generated by the deformation of the surrounding rock reaches the breaking force of the anchor cable, due to the tension of the surrounding rock being greater than the friction force between the combined body of the tapered sleeve 1006 and the bushing 1008 and the connecting pipe 1007, the combined body of the tapered sleeve 1006 and the bushing 1008 slides in the connecting pipe 1007, and the controllable elongation prestressed anchor cable 100 elongates; as the tension of the surrounding rock continuously increases, the tapered sleeve 1006 continuously moves upward, and the overlapping part in the connecting pipe 1007 continuously decreases until it reaches the uppermost end and enters the connecting sleeve II 1009, as Figure 6 shown, and its maximum elongation is the length of the L section in Figure 1 . During this process, the length of the controllable elongation prestressed anchor cable 100 continuously increases, the cross-sectional area of the roadway continuously decreases, and the anchor cable does not reach the maximum breaking force, so the support effect is still reliable and the safety production is guaranteed.

[0057] In the second aspect of the present invention, as Figures 1-8 shown, there is also provided a support device for a large-deformation roadway, including:

[0058] The controllable elongation prestressed anchor cable 100 described above;

[0059] A stirrer 200, including a drill rig connecting sleeve 2001, a triangular plate 2002 and a nut connector 2006. The upper end of the drill rig connecting sleeve 2001 is connected to the nut connector 2006, the nut connector 2006 is connected to the ball nut 1002, the lower end of the drill rig connecting sleeve 2001 is connected to the drill rig, the triangular plate 2002 is installed on the drill rig connecting sleeve 2001. When the stirrer 200 works, it drives the ball nut 1002 to rotate, and at the same time also drives the connecting sleeve Ⅰ 1005, the connecting pipe 1007, the bushing 1008, the tapered sleeve 1006 and the steel strand 1010 to rotate;

[0060] A prestress installer 300 for tensioning the steel strand 1010.

[0061] As one kind of the embodiments, as Figure 2 、 Figure 3 shown, the stirrer 200 includes a drill rig connecting sleeve 2001, a triangular plate 2002 and a nut connector 2006;

[0062] The outer circle of the upper end of the drill rig connecting sleeve 2001 is provided with threads, and the lower end is a regular polygon structure for connecting the drill rig;

[0063] The middle of the triangular plate 2002 is provided with a hole for installing the rotating seat 2003. Each of the three corners of the triangular plate 2002 is provided with a hole for placing the guide rod sleeve 2009 to form a triangular support structure. The triangular plate 2002, the rotating seat 2003 and the guide rod sleeve 2009 form an integral body;

[0064] The upper end of the nut connector 2006 is provided with a regular polygon inner hole for installing the ball nut 1002 during work, and the lower end inner hole is a threaded hole for connecting with the threads at the upper end of the drill rig connecting sleeve 2001. The outer shape of the nut connector 2006 is a cylinder, and it is installed in the hole of the rotating seat 2003. The outer circle of the nut connector 2006 and the inner hole of the rotating seat 2003 cooperate to form the shaft and hole for installing the bearing 2004, and the bearings 2004 are spaced by a retaining ring Ⅰ 2005.

[0065] As one kind of the embodiments, as Figure 2 、 Figure 3As shown in the figure, a bushing 2010 is installed inside the guide rod sleeve 2009. A ejector rod 2008 is installed inside the guide rod sleeve 2009 and the bushing 2010. A spring 2007 is installed on the ejector rod 2008 to form a three-point elastic support for the support. The head of the ejector rod 2008 is spherical to form a surface contact with the support. When encountering uneven surrounding rock, the height can be automatically adjusted by the elastic force of the spring 2007; the ball head nut 1002 is inserted into the polygonal hole of the nut connector 2006 of the agitator 200 during operation, and the polygon at the lower end of the drill rig connecting sleeve 2001 is inserted into the hole of the rock bolt drill rig; when the agitator 200 is working, it drives the ball head nut 1002 to rotate, and at the same time also drives the rotation of the parts combination such as the connecting sleeve I 1005, the connecting pipe 1007, the bushing 1008, the tapered sleeve 1006, and the steel strand 1010.

[0066] It should be noted that the working principle of the agitator 200 is as follows:

[0067] The spherical head of the ejector rod 2008 part supports on the protruding lower bottom surface of the tray 1004. The ball head nut 1002 is inserted into the polygonal hole of the nut connector 2006, and the outer polygon of the drill rig connecting sleeve 2001 is inserted into the polygonal sleeve of the drill rig. Due to the installation of the plunger 1001 at the end of the ball head nut 1002, it can only be assembled to the end of the screw rod 1003. Start the rock bolt drill rig. The rock bolt drill rig drives the nut connector 2006 and the ball head nut 1002 to rotate, and the agitator 200 also follows to make a rotational movement, and at the same time drives the controllable elongation prestressed anchor cable 100 to rotate. Due to the continuous friction between the anchoring agent at the top of the anchor cable and the rock wall, the packaging bag of the anchoring agent is damaged, and the anchoring agent flows out of the package. The agitator 200 continues to rotate, and the anchor cable continuously rotates and advances until the bottom of the hole, so that the anchoring agent is evenly stirred. When the controllable elongation prestressed anchor cable 100 is anchored, start the drill rig again. When the output torque of the agitator is greater than the torque of the plunger 1001, the plunger 1001 automatically opens, and the ball head nut 1002 continues to move upward along the axis of the screw rod 1003 until it reaches the tray 1004, thereby locking the anchor cable to achieve the purpose of rapid support. At this time, the requirement of the pre-tightening force of the anchor cable has not been reached, and secondary tensioning is required.

[0068] As one of the embodiments, as Figure 4 、 Figure 5 shown, the prestressed installer 300 includes an outer cylinder 3005, a piston 3006, a housing 3009, and a spherical pad 3011;

[0069] The upper end face of the outer cylinder 3005 has an external thread for connecting with the internal thread at the lower end of the outer shell 3009, and the lower end face has a flange for connecting with the cover plate 3002. The inner cavity of the outer cylinder 3005 is a cylinder for the piston 3006 to perform reciprocating linear motion along it. There is a hole in the middle of the piston 3006 for the inner sleeve 3007 to pass through; one end of the inner hole of the inner sleeve 3007 is threaded and is used to connect with the screw rod 1003 in the controllable elongation prestressed anchor cable 100 during operation, and the cylinder at the other end is slightly larger and is used to abut against the end face of the piston 3006. When the piston 3006 moves, it drives the inner sleeve 3007 to move together;

[0070] The upper and lower end faces of the spherical washer 3011 are both spherical surfaces, which are respectively abutted against the lower spherical surface of the tray 1004 and the upper spherical surface of the outer shell 3009 in the controllable elongation prestressed anchor cable 100. By setting the spherical washer 3011, the axis of the prestress installer 300 and the tray 1004 can be kept relatively perpendicular, avoiding the deformation and bending of the connecting pipe 1007 in the controllable elongation prestressed anchor cable 100 and causing stress concentration.

[0071] As one of the embodiments, as Figure 4 、 Figure 5 shown, the prestress installer 300 further includes a gear I 3010 and a gear II 3004. The gear I 3010 is an external gear with a polygonal inner hole at the upper end and the inner hole at the lower end is communicated with it. The gear II 3004 is an external gear and meshes with the gear I 3010. The upper end inner hole of the gear II 3004 is a cylinder for installing the small shaft 3008, and the lower end is used for installing the ratchet wrench 3001.

[0072] It should be noted that the principle of the prestress installer 300 is as follows:

[0073] The upper spherical surface of the spherical washer 3011 abuts against the bottom surface of the tray 1004, and the lower spherical surface abuts against the spherical surface of the outer shell 3009. The inner sleeve 3007 is firmly connected with the screw rod 1003. Open the oil inlet valve. As the oil is continuously supplied, the oil pressure above the piston 3006 is greater than the spring force below, pushing the piston 3006 to move downward along the inner wall of the outer cylinder 3005, playing a tensioning role on the steel strand 1010, and the screw rod 1003 is stretched by a certain distance; rotate the ratchet wrench 3001, the gear II 3004 drives the gear I 3010 to rotate, and the ball head nut 1002 moves upward along the axis direction of the screw rod 1003, and the upward movement distance is the tensioning distance of the anchor cable. Close the valve. At this time, the elastic force of the return spring 3003 is greater than the force above the piston 3006, and the piston 3006 resets. In this way, the piston 3006 moves repeatedly, and the anchor cable is tensioned.

[0074] In the third aspect of the present invention, as Figures 1-8As shown, a support method for the support equipment for large-deformation roadways is also provided, including the following steps:

[0075] S1. Drilling holes with a drill;

[0076] S2. Put the anchoring agent into the bolt hole, and push one end of the prestressed anchor cable 100 with controllable elongation against the anchoring agent and push it into the bolt hole;

[0077] S3. Place the tray 1004;

[0078] S4. Assemble the ball head nut 1002 onto the screw rod 1003 at the lower end of the prestressed anchor cable 100 with controllable elongation;

[0079] S5. Insert the ball head nut 1002 into the agitator 200;

[0080] S6. Start the bolt drill, the agitator 200 rotates to drive the ball head nut 1002 and the prestressed anchor cable 100 with controllable elongation to rotate. At this time, the anchoring agent also rotates along with it and continuously collides with the rock wall to generate friction, and punctures the outer package of the anchoring agent, and the anchoring agent flows out from the package. The continuous rotation of the agitator 200 realizes the rapid, efficient, safe and uniform mixing of the anchoring agent;

[0081] S7. Stop for a period of time until the anchoring agent solidifies, and the steel strand rod body solidifies with the surrounding rock;

[0082] S8. Start the drill, the agitator 200 rotates to drive the ball head nut 1002 to rotate. At this time, since the upper end of the anchor cable has been anchored and cannot rotate, the torque transmitted by the drill is greater than the resistance of the plunger 1001 in the ball head nut 1002, and the plunger 1001 is automatically pushed out. The ball head nut 1002 moves along the axis of the screw rod 1003 until it reaches the concave nest of the tray 1004, and the screw rod is locked to achieve rapid installation; it should be noted that the pre-tightening force of the anchor cable during the initial locking depends on the torque of the drill;

[0083] S9. Secondary fastening: Connect the screw rod 1003 at the lower end of the ball head nut 1002 to the prestressing installer 300. The hydraulic oil pump starts to inject oil into the prestressing installer 300. The high-pressure oil enters the cavity of the cylinder block through the oil inlet hole. Since the oil inlet pressure at the upper end of the piston 3006 is greater than the spring force at the lower end, the oil pressure pushes the piston 3006 to move downward along the inner wall of the outer cylinder 3005. Because the shoulder of the inner sleeve 3007 abuts against the piston 3006 and the inner sleeve 3007 and the piston 3006 are fixed together by screws along the circumference, the inner sleeve 3007 also moves downward simultaneously with the piston 3006. Since the internal thread of the inner sleeve 3007 and the external thread of the screw rod 1003 are already integrated, the steel strand 1010 also moves downward in a tensile motion, thus achieving the purpose of prestress tensioning. Additionally, the distance that the ball head nut 1002 moves upward along the axis of the screw rod 1003 is the distance of anchor cable tensioning. The magnitude of the anchor cable pre-tightening force depends on the specification of the prestressing installer 300.

[0084] The present invention is applicable to the field of underground engineering support under large deformation and complex geological conditions. Especially in mine roadways, it can effectively address the problem of anchor cable breakage caused by large deformation of roadway surrounding rock. By using a ball head nut, a high-strength prestressed tray, and a prestressing installer to perform secondary tensioning on the anchor cable, the prestress can be adjusted simultaneously to adapt to different support requirements and geological conditions. For underground engineering projects such as mine roadways with high requirements for safety and construction speed, the present invention provides a reliable and economical solution, ensuring efficient support effects can still be achieved under complex conditions, reducing long-term maintenance costs, and improving economic benefits.

[0085] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0086] In addition, those skilled in the art can understand that although some embodiments described herein include certain features contained in other embodiments rather than other features, the combination of features of different embodiments also means being within the protection scope of the present invention and forms different embodiments. For example, in the above embodiments, those skilled in the art can use them in a combined manner according to the known technical solutions and the technical problems to be solved by this application.

[0087] The above are only the preferred embodiments of the present invention, and there is no limitation to the present invention in any form. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art of this patent, without departing from the scope of the technical solution of the present invention, can make some changes or modifications using the technical content prompted above into equivalent embodiments of equivalent changes. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A prestressed anchor cable with controllable elongation, characterized in that: It includes a screw, a tray, a taper sleeve, a connecting pipe and a sleeve. The upper end of the connecting pipe is connected to the connecting sleeve II, the lower end of the connecting pipe is connected to the connecting sleeve I, the connecting sleeve I is connected to the screw, the tray is installed on the screw, the lower end of the connecting pipe is provided with a taper hole, the taper sleeve is installed in the taper hole, the upper end of the sleeve is provided with a countersunk hole for installing the steel strand, and the lower end of the sleeve is connected to the taper sleeve after passing through the connecting sleeve II and the connecting pipe; The screw, connecting sleeve I, connecting pipe and connecting sleeve II are connected as a whole, and the cone sleeve and shaft sleeve are connected as a whole. When the rock mass changes, the cone sleeve and the shaft sleeve slide together along the inner wall of the connecting pipe.

2. The prestressed anchor cable with controllable elongation according to claim 1, characterized in that: The upper and lower ends of the connecting pipe are respectively processed with external threads and the lower end is provided with the tapered hole, the taper of the tapered hole is consistent with the taper of the outer circle of the tapered sleeve, and the inner hole of the tapered sleeve is a threaded hole; The lower end of the sleeve is processed with an external thread, and the lower end of the sleeve passes through the connecting sleeve II and the connecting pipe and is connected to the internal threaded hole of the tapered sleeve; the upper and lower ends of the connecting sleeve I are respectively processed with threaded holes, the upper threaded hole is connected to the connecting pipe, and the lower threaded hole is connected to the screw.

3. The prestressed anchor cable with controllable elongation according to claim 1, characterized in that: The lower end of the screw rod is connected with the ball nut, and one end of the internal thread hole of the ball nut is connected with the plunger.

4. The prestressed anchor cable with controllable elongation according to claim 1, characterized in that: The maximum elongation is the difference between the length of the connecting pipe and the length of the vertical section of the cone sleeve.

5. A support device for a large deformation tunnel, characterized in that: include: The prestressed anchor cable with controllable elongation as claimed in any one of claims 1 to 4; The stirrer comprises a drilling rig connection sleeve, a triangular plate and a nut connector. The upper end of the drilling rig connection sleeve is connected to the nut connector, the nut connector is connected to the ball nut, the lower end of the drilling rig connection sleeve is connected to the drilling rig, and the triangular plate is installed on the drilling rig connection sleeve. When the stirrer is working, it drives the ball nut to rotate, and also drives the connection sleeve I, the connection pipe, the shaft sleeve, the cone sleeve, and the steel strand to rotate; Prestressing installer, used for tensioning steel strands.

6. A support device for a large deformation tunnel according to claim 5, characterized in that: The agitator comprises: The drilling rig connecting sleeve has a threaded upper outer circle and a regular polygonal structure at the lower end, and is used to connect the drilling rig; A triangular plate, in which a rotating seat is installed in the middle, and guide rod sleeves are respectively provided on the three corners of the triangular plate to form a triangular support structure, and the triangular plate, the rotating seat and the guide rod sleeve form a whole; The nut connector has an inner hole at its upper end for installing the ball nut, and the inner hole at its lower end is a threaded hole for threaded connection with the drilling rig connecting sleeve. The nut connector is installed in the hole of the rotating seat, and the outer circle of the nut connector cooperates with the inner hole of the rotating seat to form a shaft and hole for installing the bearing.

7. A support device for a large deformation tunnel according to claim 6, characterized in that: A bushing is installed in the guide rod sleeve, a push rod is installed in the guide rod sleeve and the bushing, and a spring is installed on the push rod to form a three-point elastic support for the support.

8. The support equipment for a large deformation tunnel according to claim 5, characterized in that: The prestressed installer comprises an outer cylinder, a piston, an outer shell and a spherical pad; The upper end of the outer cylinder is connected to the outer shell, and the lower end is connected to the cover plate. The inner cavity of the outer cylinder is a cylinder, and a reset spring and a piston are installed to make the piston reciprocate linearly. A hole for the inner sleeve to pass through is provided in the piston. One end of the inner sleeve is connected to the screw in the controllable elongation prestressed anchor cable, and the other end is used to abut against the end face of the piston. When the piston moves, the inner sleeve is driven to move together. The upper and lower end surfaces of the spherical pad are both spherical surfaces, which are respectively in contact with the lower spherical surface of the tray in the controllable elongation prestressed anchor cable and the upper spherical surface of the shell.

9. A support device for a large deformation tunnel according to claim 8, characterized in that: The prestressed installer also includes gear I and gear II. Gear I is an external gear with a polygonal inner hole at the upper end and an inner hole at the lower end that penetrates the gear. Gear II is an external gear and meshes with gear I. The inner hole at the upper end of gear II is a cylinder for installing a small shaft, and the lower end is used to install a ratchet wrench.

10. A supporting method for a supporting device for a large deformation tunnel according to any one of claims 5 to 9, characterized in that: The following steps are involved: S1, drilling with drilling rig; S2. Put the anchoring agent into the anchor hole, and push one end of the controllable elongation prestressed anchor cable against the anchoring agent and into the anchor hole; S3, place the pallet; S4, assembling the ball nut onto the screw rod at the lower end of the controllable elongation prestressed anchor cable; S5, insert the ball nut into the agitator; S6, start the anchor drilling rig, the agitator rotates to drive the ball head nut and the prestressed anchor cable with controllable elongation to rotate, at this time the anchor also rotates synchronously and continuously collides and rubs against the rock wall, and punctures the outer package of the anchor, the anchor flows out of the package, and the agitator rotates continuously to stir the anchor; S7, stop for a while to wait for the anchoring agent to solidify, and the steel strand rod body and the surrounding rock to solidify together; S8, start the drilling rig, the agitator rotates to drive the ball nut to rotate, and when the torque delivered by the drilling rig is greater than the plunger resistance in the ball nut, the plunger is automatically ejected, and the ball nut moves along the axis of the screw until it reaches the recess of the tray, and the locking screw is quickly installed; S9, secondary tightening, connect the screw at the lower end of the ball head nut with the prestressed installer, and the hydraulic oil pump starts to inject oil into the prestressed installer. The high-pressure oil enters the cavity of the cylinder body from the oil inlet hole. Since the oil inlet pressure at the upper end of the piston is greater than the spring force at the lower end, the oil pressure pushes the piston to move downward along the inner wall of the outer cylinder, and the inner sleeve moves downward synchronously with the piston. At the same time, the steel strand stretches downward to achieve prestressing.

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