Rock bolt installation method and rock bolt installation device

Abstract

This method can significantly improve the efficiency of the series of operations that involves injecting an anchoring material into a borehole formed in the natural ground and then driving a rock bolt into the borehole so that it is fixed by the anchoring material. [Solution] A rock bolt installation method comprising a first step of pressing a hollow rock bolt (10) with its tip blocked and a discharge hole (16) formed near the tip against the back of a borehole (104) formed in the natural ground (101); and a second step of injecting an anchoring material (100) from the rear end opening (13) of the hollow rock bolt (10) toward the tip while maintaining the hollow rock bolt (10) pressed against the back of the borehole (104), discharging the anchoring material (100) into the borehole (104) from the discharge hole (16), and confirming the return of the anchoring material (100) from the mouth of the borehole (104).

Description

[Technical Field]

[0001] The present invention relates to a rock bolt installation method and a rock bolt installation device for installing rock bolts so that they are fixed in place using an anchoring material injected into a borehole. [Background technology]

[0002] Conventionally, when fixing an anchoring-type rock bolt for tunnel support in a borehole with an anchoring material, for example, the following procedure is performed: a borehole 208 is formed by drilling a natural ground 201 on which sprayed concrete 202 has been formed using a drifter 205, a drilling rod 206, and a drilling bit 207 on a guide shell 204 (see Figures 8(a) and (b)); an injection pipe 209 of an anchoring material 210 is manually inserted into the borehole 208 to inject the anchoring material 210 into the borehole 208 (see Figures 8(c) and (d)); after the injection pipe 209 is removed from the borehole 208, a rock bolt 211 is inserted into the borehole 208 and cast (see Figures 8(d) and (e)); and a bearing plate 212 and a nut 213 are attached to the protruding part of the rock bolt 211 protruding from the natural ground 201.

[0003] Patent document 1 proposes that in the installation procedure for this rock bolt 211, an injection pipe delivery device is attached to a drifter and the rotational driving force of the drifter is used to move the injection pipe back and forth, thereby mechanizing the work of inserting the injection pipe of the fixing material into the borehole and injecting the fixing material.

[0004] Furthermore, Patent Document 2 proposes that a rock bolting device that switches between injecting an anchoring material and casting a rock bolt be attached to a guide shell, the rock bolting device be used to insert the injection pipe into the borehole, the injection pipe be retracted while injecting the anchoring material, and the injection pipe be removed from the borehole, and the rock bolting device be used to cast a rock bolt into the borehole after the anchoring material has been injected, thereby mechanizing the insertion and removal of the injection pipe into the borehole and the insertion of the rock bolt into the borehole. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-83654 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-144349 Summary of the Invention [Problem to be solved by the invention]

[0006] While the devices in Patent Documents 1 and 2 mechanize part of the series of operations from injecting an anchoring material into a borehole to driving a rock bolt, and thus can improve the efficiency of the work to a certain extent, both require the insertion of an anchoring material injection pipe into the borehole, removal of the pipe, and then the insertion of the rock bolt into the borehole, so it is difficult to say that the efficiency of the work has been sufficiently improved. Therefore, there is a need to improve the efficiency of the series of operations from injecting an anchoring material into a borehole and driving a rock bolt into the borehole so that the anchoring material will fix the bolt.

[0007] The present invention has been proposed in consideration of the above-mentioned problems, and aims to provide a rock bolt installation method and rock bolt installation device that can significantly improve the efficiency of the series of operations that involve injecting an anchoring material into a borehole formed in the natural ground and then driving the rock bolt into the borehole so that it is fixed by the anchoring material. [Means for solving the problem]

[0008] The rock bolt installation method of the present invention is characterized by comprising a first step of pressing a hollow rock bolt with a closed tip and a discharge hole formed near the tip against the back of a borehole formed in the natural ground, and a second step of injecting an anchoring material from the rear end opening of the hollow rock bolt toward the tip while maintaining the hollow rock bolt pressed against the back of the borehole, discharging the anchoring material into the borehole from the discharge hole, and confirming the return of the anchoring material from the mouth of the borehole. According to this method, the hollow rock bolt is pressed against the deep end of the borehole, and an anchoring material is injected into the borehole through the hollow rock bolt, thereby securing the hollow rock bolt pressed against the deep end of the borehole with the anchoring material. This allows the hollow rock bolt to be secured in place with the anchoring material and driven into the borehole without the need to insert and remove an injection pipe. This significantly improves the efficiency of the process of injecting the anchoring material into a borehole formed in the natural ground and then driving the rock bolt into the borehole. Furthermore, since the hollow rock bolt can be secured in place with the anchoring material while being maintained pressed against the deep end of the borehole, the hollow rock bolt can be reliably secured in the appropriate position relative to the borehole. Furthermore, since the anchoring material is injected while the hollow rock bolt is maintained pressed against the deep end of the borehole, proper injection of the anchoring material into the borehole can be reliably confirmed by checking the return of the anchoring material.

[0009] The rock bolt installation method of the present invention is characterized in that, in the first step, the fitting portion provided on the outer periphery near the rear end of the hollow rock bolt and the fitting portion of the connector are fitted into each other in the axial direction of the hollow rock bolt, thereby removably fitting the hollow rock bolt and the connector, and the hollow rock bolt is pressed against the inner side of the borehole via the connector, and in the second step, an anchoring material is supplied to the rear end opening of the hollow rock bolt via the hollow portion of the connector. With this, by fitting the fitting portion of the hollow rock bolt into the fitted portion of the connector in the axial direction of the hollow rock bolt, the hollow rock bolt can be pressed against the back of the borehole via the connector, thereby maintaining the fitted and fixed state between the hollow rock bolt and the connector.In addition, an anchoring material can be smoothly supplied to the rear end opening of the hollow rock bolt through the hollow portion of the connector, which maintains the fitted and fixed state with the hollow rock bolt.

[0010] The rock bolt installation method of the present invention is characterized in that in the first step, a support plate inserted onto the hollow rock bolt is pressed against the periphery of the mouth of the borehole, and in the second step, an anchoring material is injected while maintaining the support plate pressed against the periphery of the mouth of the borehole. This allows the anchoring material to be injected while keeping the support plate pressed against the mouth of the borehole, making it possible to properly inject the anchoring material without using a packer to block the area near the mouth of the borehole.

[0011] The rock bolt driving device of the present invention is characterized by comprising: a pressing mechanism that presses a hollow rock bolt, which has a closed tip and a discharge hole formed near the tip, against the back side of a borehole formed in the ground; a connecting body having an engaged portion into which an engaging portion provided on the outer periphery near the rear end of the hollow rock bolt is removably fitted in the axial direction of the hollow rock bolt; and a hollow portion that communicates with the engaged portion and into which an anchoring material supply pipe that supplies anchoring material to the rear end opening of the hollow rock bolt is fitted; and a transmission mechanism that transmits the pressing force of the pressing mechanism to the connecting body. According to this system, the hollow rock bolt is pressed against the inner side of the borehole by the pressing mechanism via the connector and transmission mechanism, and then an anchoring material is injected into the borehole via the hollow rock bolt, thereby securing the hollow rock bolt pressed against the inner side of the borehole with the anchoring material. This allows the rock bolt to be secured in the borehole with the anchoring material without inserting and removing an injection pipe into the borehole. This significantly improves the efficiency of the process of injecting the anchoring material into a borehole formed in the natural ground and then driving the rock bolt into the borehole. Furthermore, since the hollow rock bolt can be secured in the appropriate position relative to the borehole with the anchoring material while maintaining the hollow rock bolt pressed against the inner side of the borehole, the hollow rock bolt can be reliably secured in the appropriate position relative to the borehole. Furthermore, by injecting the anchoring material while maintaining the hollow rock bolt pressed against the inner side of the borehole, proper injection of the anchoring material into the borehole can be confirmed reliably by checking the return of the anchoring material.

[0012] The rock bolt driving device of the present invention is characterized in that a spherical portion is provided at the rear end of the connecting body, a spherical seat that receives the spherical portion is provided on the receiving material of the connecting body of the transmission mechanism, the fixing material supply pipe is inserted into a through hole in the receiving material that opens at the spherical seat, the fixing material supply pipe is fitted into the hollow portion of the connecting body that opens at the spherical portion, and a tilting control part is provided to control the tilting of the spherical portion and the spherical seat. This allows the tilting of the spherical portion and the spherical seat, and the tilting control portion that moderately controls this tilting, to adapt to cases where the pressing direction of the pressing mechanism is slightly tilted relative to the axial direction of the borehole or the axis of the hollow rock bolt, and allows the hollow rock bolt to be reliably pressed against the deep side of the borehole.

[0013] The lock bolt driving device of the present invention is characterized in that the tilt regulating portion elastically biases the spherical portion so as to press it against the spherical seat. With this, the tilting control portion elastically biases the spherical portion against the spherical seat, thereby allowing the connecting body and the receiving material of the transmission mechanism to be stably abutted at all times without placing any extra load on the hollow lock bolt. [Effects of the Invention]

[0014] According to the present invention, the efficiency of the series of operations of injecting an anchoring material into a borehole formed in the natural ground and driving a rock bolt into the borehole so that it is fixed by the anchoring material can be greatly improved. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an explanatory diagram showing an embodiment of a rock bolt driving device according to the present invention and a hollow rock bolt to be driven into the natural ground. [Figure 2] A plan view showing a connector, a transmission mechanism, an anchoring material supply pipe, and a portion of a hollow rock bolt in an embodiment of a rock bolt driving device. [Figure 3] A side view showing a connector, a transmission mechanism, an anchoring material supply pipe, and a portion of a hollow rock bolt in an embodiment of a rock bolt driving device. [Figure 4] 1 is a perspective view showing a connector, a transmission mechanism, an anchoring material supply pipe, and a portion of a hollow rock bolt in an embodiment of a rock bolt driving device. FIG. [Figure 5] (a) is a side view showing the connector and the fixing material supply pipe in the rock bolt driving device of the embodiment, (b) is a side view showing the transmission mechanism other than the hollow rod in the same rock bolt driving device, (c) is a side view showing the hollow rod in the same rock bolt driving device, (d) is a side view showing the bolt with a compression spring in the same rock bolt driving device, (e) is a view from the arrow A in Figure (a) of the same figure, (f) is a view from the arrow B in Figure (b) of the same figure, and (g) is a view from the arrow C in Figure (b) of the same figure. [Figure 6] (a) is a partial cross-sectional view of an embodiment of a rock bolt driving device with a hollow rock bolt fitted into the connector, and (b) is a cross-sectional explanatory view illustrating the tilting of the connector in the embodiment of the rock bolt driving device. [Figure 7] 1(a) to 1(e) are process diagrams illustrating the construction procedure of a rock bolt construction method according to an embodiment of the present invention. [Figure 8] (a) to (e) are process diagrams illustrating the installation procedure for conventional anchoring material-fixed rock bolts. DETAILED DESCRIPTION OF THE INVENTION

[0016] [Rock bolt installation method and rock bolt installation device according to the embodiment] A rock bolt installation method and rock bolt driving device 1 according to an embodiment of the present invention are used, for example, when driving a hollow rock bolt 10 into the natural ground 101 of a tunnel T shown in Figure 1. Shotcrete 102 is poured into the surrounding wall of the natural ground 101 of the tunnel T in Figure 1, and the hollow rock bolt 10 is inserted through the shotcrete 102 into a borehole 104 formed in the natural ground 101, and an anchoring material 100 is injected into the borehole 104 so that the hollow rock bolt 10 is fixed in place by the anchoring material 100 (see Figure 7).

[0017] As shown in Figures 1 to 7, the rock bolt driving device 1 comprises a guide shell 3 supported by the boom 2 of a drill jumbo, and a drifter 4 mounted on the guide shell 3 and having a centralizer 31 at its tip, which is movable along the extension direction of the guide shell 3, and the drifter 4 corresponds to a pressing mechanism that presses the hollow rock bolt 10 against the inner side of the borehole 104. Furthermore, the rock bolt driving device 1 comprises a connector 5 connected to the hollow rock bolt 10, and a transmission mechanism 6 that transmits the pressing force of the drifter 4, which corresponds to the pressing mechanism, to the connector 5.

[0018] The connector 5 has a generally cylindrical tubular portion 51 located on the front side, a generally disk-shaped flange portion 52 located on the rear side, and a small-diameter tubular portion 53 formed in a cylindrical shape with an outer diameter smaller than that of the tubular portion 51 and located between the tubular portion 51 and the flange portion 52. A fitted portion 54 is formed inside the tubular portion 51 so as to open at the front end, and a fitting portion 11 provided on the outer periphery near the rear end of the hollow lock bolt 10 is removably fitted into the fitted portion 54 in the axial direction of the hollow lock bolt 10. In the illustrated example, the fitting portion 11 is a hexagonal nut provided on the outside of the peripheral wall 12 of the hollow lock bolt 10, and the fitted portion 54 is formed in the shape of a hexagonal hole into which the hexagonal nut fits.

[0019] A cylindrical hollow portion 55 that communicates with the fitted portion 54 is formed toward the rear of the inside of the tubular portion 51, and the hollow portion 55 is formed with a diameter and length that allow the peripheral wall 12 that protrudes rearward from the fitting portion 11 of the hollow lock bolt 10 to be inserted therein. Furthermore, a cylindrical hollow portion 56 is formed in the part of the inside of the tubular portion 51 rearward of the hollow portion 55, the small-diameter tubular portion 53, and the flange portion 52 so as to communicate from the hollow portion 55 to the rear end of the flange portion 52. In this embodiment, a spherical portion 57 is provided at the rear end of the flange portion 52, which is the rear end of the connector 5, and the hollow portion 56 is formed so as to communicate from the hollow portion 55 to the rear end of the spherical portion 57, and is open at approximately the center of the spherical portion 57.

[0020] The hollow portion 56 is formed with a diameter corresponding to the outer diameter of the fixing material supply pipe 7 that supplies fixing material 100 such as mortar, and the fixing material supply pipe 7 is fitted into the hollow portion 56. The fixing material 100 supplied from the fixing material supply pipe 7 is supplied so as to be discharged into the hollow portion 55 that communicates with the fitted portion 54 or into the hollow portion 56 that is continuous with the hollow portion 55, and the fixing material 100 is supplied to the rear end opening 13 of the part of the hollow rock bolt 10 inserted into the hollow portion 55 and to the interior 14 of the hollow rock bolt 10.

[0021] The transmission mechanism 6 has a disk-shaped receiving material 61 having an outer diameter that corresponds approximately to that of the flange portion 52, a disk-shaped transmission plate 62 having an outer diameter that corresponds approximately to that of the receiving material 61 and arranged at a distance behind the receiving material 61, an attachment shaft 63 that is fixed to the transmission plate 62 so as to protrude rearward from approximately the center of the transmission plate 62, and a plurality of transmission shafts 64 that are arranged at predetermined intervals around the circumferential direction of the receiving material 61 and are fixed to the receiving material 61 so as to protrude rearward from the receiving material 61. Each transmission shaft 64 is provided so as to bridge the receiving material 61 and the transmission plate 62, and is fixed to the transmission plate 62 with a bolt and nut.

[0022] An insertion hole 611 is formed in the receiving member 61 at a midpoint between the transmission shafts 64 in the circumferential direction, and an insertion hole 521 is also formed in a position corresponding to the insertion hole 611 in the flange portion 52 of the connecting body 5 that abuts against the receiving member 61. A shaft portion 651 of a compression spring bolt 65 is inserted into the insertion hole 521 of the flange portion 52 and the insertion hole 611 of the receiving member 61, which are arranged at corresponding positions, and a compression spring 652 of a coil spring is fitted onto the shaft portion 651 that protrudes to the rear side of the receiving member 61, and a nut 653 that prevents the compression spring 652 from falling off is screwed onto the shaft portion 651.

[0023] A spherical seat 612 that receives the spherical portion 57 formed on the flange portion 52 of the connecting body 5 is provided approximately in the center of the front surface of the receiving material 61, and the flange portion 52 abuts against the receiving material 61 so that the spherical portion 57 is received by the spherical seat 612. The compression spring bolt 65 elastically biases the spherical portion 57 of the flange portion 52 so as to press it against the spherical seat 612 of the receiving material 61, and also regulates tilting due to sliding between the spherical portion 57 and the spherical seat 612, and the compression spring bolt 65 corresponds to a tilting regulation portion.

[0024] A through hole 613 that opens at the spherical seat 612 is formed approximately in the center of the receiving material 61, and the fixing material supply pipe 7 is introduced to the rear side of the receiving material 61 through the gap between the transmission shafts 64, and the fixing material supply pipe 7 is inserted into the through hole 613 of the receiving material 61, and the fixing material supply pipe 7 that leads out from the through hole 613 is introduced into the hollow portion 56 of the connecting body 5 that opens at the spherical portion 57, and the fixing material supply pipe 7 is fitted into the hollow portion 56.

[0025] The front portion of a substantially cylindrical hollow rod 66 is fitted onto the mounting shaft 63 of the transmission mechanism 6, and the rear portion of the hollow rod 66 is fitted onto the shank rod of the drifter 4. The interior of the hollow portion 55 of the connector 5 and the interior of the hollow rod 66 may be connected by a water washing hose 67, and the fixing material 100 remaining inside the connector 5 may be washed away using water supplied from the drifter 4.

[0026] The hollow rock bolt 10 in the illustrated example that is driven by the rock bolt driving device 1 has a rope thread formed over the entire length of the peripheral wall 12, and a hexagonal nut that corresponds to the fitting part 11 is provided on the outside of the peripheral wall 12 and is threaded onto the rope thread. A tip cone 15 is fixed to the tip of the hollow rock bolt 10, and the tip of the hollow rock bolt 10 or the tip of the interior 14 of the hollow rock bolt 10 is closed by the tip cone 15. A discharge hole 16 is formed near the tip of the hollow rock bolt 10 to discharge an anchoring material 100 from the interior 14 of the hollow rock bolt 10 to the outside or into a borehole 104.

[0027] The hollow rock bolt 10 driven into the natural ground 101 is fully fixed to the hole wall of the borehole 104 with the anchoring material 100, and a bearing plate 17 is extrapolated to the part of the hollow rock bolt 10 protruding outward from the borehole 104 and is placed at the mouth of the borehole 104. Furthermore, a nut, which is a fitting part 11, is screwed onto the part of the hollow rock bolt 10 protruding outward from the borehole 104 via the bearing plate 17, and by tightening it, the axial force of the hollow rock bolt 101 resists deformation of the natural ground, and the hollow rock bolt 10 fixed to the natural ground 101 by the anchoring material 100 forms a natural ground arch around the tunnel T, and the stress of the natural ground 101 is distributed to the shotcrete 102 via the bearing plate 17.

[0028] When the rock bolt installation method of this embodiment is performed using the rock bolt driving device 1, first, a drilling rod 81 having a drilling bit 82 is attached to the drifter 4, and the drilling bit 82 is used to drill a borehole 104 in the natural ground 101 so as to penetrate the lining concrete 103 and the shotcrete 102 (see Figures 7(a) and 7(b)). After the borehole 104 is formed, the drilling rod 81 is removed from the drifter 4.

[0029] Next, the rock bolt driving device 1 is attached to the drifter 4 via the hollow rod 66, and the fitting portion 11 of the hollow rock bolt 10 is fitted into the fitted portion 54 of the connector 5 in the axial direction of the hollow rock bolt 10, so that the hollow rock bolt 10 and the connector 5 are detachably fitted together, and the hollow rock bolt 10 is positioned so that the vicinity of its tip is gripped by the centralizer 31. A support plate 17 such as each washer is extrapolated onto the hollow rock bolt 10 in front of the centralizer 31, and the support plate 17 is held by a member installed on the centralizer 31 or in its vicinity (see Figure 7(b) and Figure 6).

[0030] Then, the guide shell 3 is advanced toward the natural ground 101, and the bearing plate 17 is pressed against the area around the mouth of the borehole 104 or the lining concrete 103, and the drifter 4 is advanced toward the natural ground 101 on the guide shell 3, and the hollow rock bolt 10 is pressed against the inner side of the borehole 104 (see Figure 7(c)). As the drifter 4 advances, the axial engagement of the hollow rock bolt 10 between the fitting portion 11 of the hollow rock bolt 10 and the fitted portion 54 of the connector 5 is strengthened, and the hollow rock bolt 10 is pressed against the inner side of the borehole 104 via the connector 5.

[0031] Also, at this time, even if the axis of the hollow rock bolt 10 is inclined at an angle α relative to the forward direction of the drifter 4 (see Figure 6(b)), the tilting caused by the sliding between the spherical portion 57 of the connecting body 5 and the spherical seat 612 of the receiving material 61 and the regulation of the tilting between the spherical portion 57 and the spherical seat 612 by the compression spring-equipped bolt 65 can change the pressing direction caused by the forward movement of the drifter 4 to the axial direction of the hollow rock bolt 10, and the hollow rock bolt 10 can be pressed against the back side of the borehole 104.

[0032] After the hollow rock bolt 10 has been pressed toward the back of the hole, while maintaining the support plate 17 pressed against the mouth of the borehole 104 and the hollow rock bolt 10 pressed toward the back of the borehole 104, a fixing material 100 such as mortar is supplied to the fixing material supply pipe 7 using the pump P, and the fixing material 100 is supplied to the rear end opening 13 of the hollow rock bolt 10 through the hollow portions 56, 55 of the connector 5, and the fixing material 100 is injected from the rear end opening 13 of the hollow rock bolt 10 toward the tip side (see Figure 7(d) and Figure 6).

[0033] The anchoring material 100 injected into the interior 14 of the hollow rock bolt 10 from the rear end opening 13 is discharged to the outside of the hollow rock bolt 10 from the discharge hole 16 near the tip of the hollow rock bolt 10, and then into the borehole 104. The return of the anchoring material 100 from the opening of the borehole 104 confirms that the anchoring material 100 has been properly injected and filled into the borehole 104 (see Figure 7(e)). After the anchoring material 100 has been properly filled into the borehole 104, the drifter 4 and guide shell 3 are retracted, and the casting is completed.

[0034] According to this embodiment, while the hollow rock bolt 10 is pressed against the deep side of the borehole 104, an anchoring material 100 such as mortar is injected into the borehole 104 through the hollow rock bolt 10, and the hollow rock bolt 10 pressed against the deep side of the hole can be fixed by the anchoring material 100. Therefore, the hollow rock bolt 10 can be fixed by the anchoring material 100 and driven into the borehole 104 without inserting and removing an injection pipe into the borehole 104. This significantly improves the efficiency of the series of operations from injecting the anchoring material 100 into the borehole 104 formed in the natural ground 101 and driving the rock bolt into the borehole 104 so that it is fixed by the anchoring material 100. Furthermore, since the hollow rock bolt 10 can be fixed by the anchoring material 100 while maintaining the state of being pressed against the deep side of the hole, the hollow rock bolt 10 can be reliably fixed in an appropriate position relative to the borehole 104. Furthermore, since the fixing material 100 is injected while the hollow rock bolt 10 is kept pressed against the inner side of the hole, proper injection of the fixing material 100 into the borehole 104 can be reliably confirmed by checking the return of the fixing material 100.

[0035] Furthermore, by fitting the fitting portion 11 of the hollow rock bolt 10 into the fitted portion 54 of the connecting body 5 in the axial direction of the hollow rock bolt 10, the hollow rock bolt 10 can be pressed against the back of the borehole 104 via the connecting body 5, thereby maintaining the fitted and fixed state between the hollow rock bolt 10 and the connecting body 5. Furthermore, the fixing material 100 can be smoothly supplied to the rear end opening 13 of the hollow rock bolt 10 via the hollow portion 55 of the connecting body 5, which maintains the fitted and fixed state with the hollow rock bolt 10.

[0036] Furthermore, by injecting the fixing material 100 while keeping the support plate 17 pressed against the mouth of the borehole 104, the fixing material 100 can be injected properly without using a packer to block the area near the mouth of the borehole 104.

[0037] In addition, the tilting of the spherical portion 57 and the spherical seat 612 and the spring-loaded bolt 65, which corresponds to a tilting control section that moderately controls this tilting, allow the hollow rock bolt 10 to be reliably pressed against the inner side of the borehole 104 when the pressing direction of the drifter 4 is slightly tilted relative to the axial direction of the borehole 104 or the axis of the hollow rock bolt 10.

[0038] Furthermore, the spring-loaded bolt 65, which corresponds to the tilting control section, elastically biases the spherical section 57 to press it against the spherical seat 612, thereby allowing the connecting body 5 and the receiving material 61 of the transmission mechanism 6 to be in constant stable contact without placing any extra load on the hollow lock bolt 10.

[0039] [Scope of the invention disclosed herein] The inventions disclosed in this specification include, in addition to the individual inventions and embodiments listed as inventions, those specified by changing partial contents of these to other contents disclosed in this specification, those specified by adding other contents disclosed in this specification to these contents, or those specified by deleting partial contents of these to the extent that partial effects are obtained and creating a generic concept.The inventions disclosed in this specification also include the following contents and modifications.

[0040] The hollow rock bolts installed in the present invention are not limited to the hollow rock bolt 10 in the above example, but may be any suitable type within the scope of the spirit of the present invention, and may, for example, have threads other than rope threads formed on the peripheral wall, or may have no threads formed on the peripheral wall, or may have their tip closed by a structure other than that for fixing the tip cone 15.

[0041] The rock bolt driving device of the present invention can also be configured as a rock bolt driving device that does not have a tilting mechanism using the spherical portion 57 and spherical seat 612 or a tilt regulating unit that moderately regulates this tilting, and a method of installing a rock bolt using this rock bolt driving device is also included in the present invention. Furthermore, the tilt regulating unit that regulates the tilting of the spherical portion and spherical seat in the rock bolt driving device of the present invention and constantly urges the spherical portion to press against the spherical seat can be any suitable unit within the scope of its applicability other than to bolt 65 with compression spring, and for example, it is possible to configure it so that a torsion spring or the like is used instead of compression spring 652, which is a coil spring.

[0042] In addition, in the above embodiment, in order to ensure reliable transmission of the pressing force from the drifter 4 to the receiving material 61, prevent interference between the transmission shaft 64 and the compression spring bolt 65, and ensure space for introducing the fixing material supply pipe 7, the transmission mechanism 6 is configured to have three transmission shafts 64 and three compression spring bolts 65 arranged circumferentially around the receiving material 61, but the number of transmission shafts 64 and three compression spring bolts 65 arranged circumferentially around the receiving material 61 can be any number within an applicable range. [Industrial Applicability]

[0043] The present invention can be used when injecting an anchoring material into a borehole in the natural ground and driving a rock bolt so that the bolt is fixed by the anchoring material. [Explanation of symbols]

[0044] 1...Rock bolt driving device 2...Boom 3...Guide shell 31...Centralizer 4...Drifter 5...Connector 51...Cylindrical portion 52...Flange portion 521...Through hole 53...Small diameter cylindrical portion 54...Engaged portion 55, 56...Hollow portion 57...Spherical portion 6...Transmission mechanism 61...Receiving material 611...Through hole 612...Spherical seat 613...Through hole 62...Transmission plate 63...Mounting shaft 64...Transmission shaft 65...Bolt with compression spring 651...Shaft portion 652...Compression spring 653...Nut 66...Hollow rod 67...Flushing hose 7...Fixing material supply pipe 81...Drilling rod 82...Drilling bit 10...Hollow rock bolt 11...Engaging portion 12...Surrounding wall 13...Rear end opening 14...Interior 15...Tip cone 16...Discharge hole 17...Support plate 100...Anchor 101...Natural ground 102...Sprayed concrete 104...Borehole 201...Natural ground 202...Sprayed concrete 204...Guide shell 205...Drifter 206...Drilling rod 207...Drilling bit 208...Borehole 209...Injection pipe 210...Anchor 211...Rock bolt 212...Support plate 213...Nut T...Tunnel P...Pump α...Inclination angle of the axis of the hollow rock bolt

Claims

1. a first step of pressing a hollow rock bolt having a closed tip and a discharge hole formed near the tip against a deep side of a borehole formed in the natural ground; a second step of injecting an anchoring material from the rear end opening of the hollow rock bolt toward the tip end while maintaining the hollow rock bolt pressed against the deep end of the borehole, discharging the anchoring material into the borehole from the discharge hole, and confirming the return of the anchoring material from the mouth of the borehole.

2. In the first step, the hollow rock bolt and the connecting body are detachably fitted together by fitting a fitting portion provided on the outer periphery near the rear end of the hollow rock bolt into a fitted portion of a connecting body in the axial direction of the hollow rock bolt, and the hollow rock bolt is pressed against the inner side of the borehole via the connecting body, 2. The method for installing a rock bolt according to claim 1, wherein in the second step, an anchoring material is supplied to the rear end opening of the hollow rock bolt through the hollow portion of the connector.

3. In the first step, a bearing plate fitted onto the hollow rock bolt is pressed against the mouth of the borehole, 3. A rock bolt installation method according to claim 1, wherein in the second step, the fixing material is injected while maintaining the bearing plate pressed against the periphery of the mouth of the borehole.

4. a pressing mechanism that presses a hollow rock bolt, the tip of which is closed and the discharge hole formed near the tip, against the inner side of a borehole formed in the natural ground; a connector having a fitted portion into which a fitting portion provided on the outer periphery near the rear end of the hollow lock bolt is detachably fitted in the axial direction of the hollow lock bolt, and a hollow portion into which an anchoring material supply pipe that communicates with the fitted portion and supplies an anchoring material to the rear end opening of the hollow lock bolt is fitted; A rock bolt driving device characterized by comprising a transmission mechanism that transmits the pressing force of the pressing mechanism to the connecting body.

5. A spherical portion is provided at the rear end of the connecting body, a spherical seat that receives the spherical portion is provided on a receiving member of the connecting body of the transmission mechanism, The fixing material supply pipe is inserted into the through hole of the receiving material that opens at the spherical seat, and the fixing material supply pipe is fitted into the hollow portion of the connecting body that opens at the spherical portion, 5. The rock bolt driving device according to claim 4, further comprising a tilt regulating portion that regulates tilting of the spherical portion and the spherical seat.

6. 6. The rock bolt driving device according to claim 5, wherein the tilt regulating portion elastically biases the spherical portion so as to press it against the spherical seat.

Images