Removable grouting casing for tunnel surrounding rock support

Abstract

The present invention discloses a detachable grouting sleeve for tunnel surrounding rock support, comprising a first end sleeve, a splicing sleeve, a tail sleeve and a second end sleeve, wherein the first end sleeve, the splicing sleeve and the second end sleeve are all provided with a grouting channel that is connected with the tail sleeve, the tail sleeve is provided with a grouting port, the grouting port is connected with the grouting channel, the first end sleeve, the splicing sleeve and the tail sleeve are sequentially connected to form a primary grouting sleeve, the second end sleeve and the tail sleeve are connected to form a secondary grouting sleeve, the first end sleeve is provided with a first connecting portion for connecting a second baffle in a main support structure, and the second end sleeve is provided with a second connecting portion for connecting a third baffle in the main support structure. The primary grouting sleeve and the secondary grouting sleeve of different lengths are formed by splicing different components, which can provide an application basis for applying multiple pre-tightening forces and strengthening the support effect at tunnel surrounding rocks of different depths.

Description

[Technical field]

[0001] The invention relates to the technical field of tunnel surrounding rock reinforcement, in particular to a detachable grouting sleeve used for tunnel surrounding rock support. [Background technology]

[0002] In the process of coal mining, due to the complexity and variability of surrounding rock conditions, support structures such as anchor rods and anchor cables play an important role in tunnel surrounding rock support, ensuring resource mining and the safety of machinery and personnel. The investigation found that the main support method for deep tunnel surrounding rock control at home and abroad is still the method of anchor rods and anchor cables combined with shotcrete support. Prestressed anchor rods can provide strong support force to shallow broken rock mass and maintain the stability of tunnel structure; prestressed anchor cables have good advantages in structural length and support strength, and have a large anchoring range. Both of them take active support as the support concept, which can give full play to the bearing capacity of surrounding rock, effectively control the violent deformation of rock mass to a certain extent, and provide a safe environment for coal mining. Compared with passive support methods, prestressed anchor rod (cable) support is significantly superior to passive support methods in terms of material cost, ease of operation and support effect.

[0003] However, as resource mining shifts to deeper areas, tunnels are buried deeper and deeper, surrounding rock stress continues to increase, and the support effect of ordinary anchor (cable) support technology becomes less and less obvious, or even fails. In the existing deep tunnel anchor (cable) support technology, local anchoring and local grouting are usually adopted, and preload is only applied once or not, which makes it difficult to provide differential support for rock masses at different depths. The difference in the mechanical structure of tunnel surrounding rocks under deep high stress is ignored, and the support effect is poor. [Summary of the invention]

[0004] The object of the present invention is to provide a detachable grouting sleeve used for tunnel surrounding rock support, which can provide an application basis for applying multiple pre-tightening forces and enhancing the support effect of tunnel surrounding rock at different depths by splicing different components to form the first-level grouting sleeve and the second-level grouting sleeve of different lengths.

[0005] The present invention provides the following technical solutions:

[0006] A detachable grouting casing used for tunnel surrounding rock support comprises a first end casing, a splicing casing, a tail casing and a second end casing, wherein the first end casing, the splicing casing and the second end casing are all provided with a grouting channel communicating with the tail casing, the tail casing is provided with a grouting port, the grouting port is communicated with the grouting channel, the first end casing, the splicing casing and the tail casing are sequentially connected to form a primary grouting casing, the second end casing and the tail casing are connected to form a secondary grouting casing, the first end casing is provided with a first connecting portion for connecting to a second baffle in a main support structure, and the second end casing is provided with a second connecting portion for connecting to a third baffle in the main support structure.

[0007] As described above, the detachable grouting casing used for tunnel surrounding rock support, the first end casing, the spliced ​​casing and the second end casing are all provided with a seepage channel communicating with the tail casing, and a piston assembly for feedback of grouting conditions is provided in the seepage channel.

[0008] As described above, the detachable grouting sleeve used for tunnel surrounding rock support, the first end sleeve is provided with a first connecting portion at one end thereof is provided with a first limiting boss protruding toward the inflow direction of the seepage channel, the seepage channel of the first end sleeve is provided with a first limiting baffle opposite to the first limiting boss, and the first limiting boss is provided with a first boss through hole connected to the seepage channel.

[0009] As described above, the detachable grouting sleeve used for tunnel surrounding rock support, the second end sleeve is provided with a second connecting portion at one end thereof is provided with a second limiting boss protruding toward the inflow direction of the seepage channel, the seepage channel of the tail sleeve is provided with a second limiting baffle, and the second limiting boss is provided with a second boss through hole connected to the seepage channel.

[0010] As described above, the detachable grouting sleeve used for tunnel surrounding rock support, the piston assembly includes a piston head and a piston rod, the piston head is arranged at one end of the piston rod and the diameter of the piston head is greater than the diameter of the piston rod.

[0011] As described above, the detachable grouting sleeve used for tunnel surrounding rock support, the piston rod in the first-level grouting sleeve includes a detachably connected spliced ​​piston rod and an anchor rod, and the piston rod in the second-level grouting sleeve is an anchor rod.

[0012] As described above, the detachable grouting sleeve used for tunnel surrounding rock support has four grouting channels and four grouting ports, the four grouting channels are evenly distributed along the circumference of the pipe wall, and the grouting direction of the grouting ports is perpendicular to the axial direction of the grouting channels.

[0013] As described above, in the detachable grouting sleeve used for tunnel surrounding rock support, the first connecting portion includes a first buckle provided on the outer surface of the sleeve at the first end.

[0014] As described above, in the detachable grouting sleeve used for tunnel surrounding rock support, the second connecting portion includes a second buckle and a limit baffle provided on the outer surface of the sleeve at the second end.

[0015] As described above, the detachable grouting sleeve used for tunnel surrounding rock support, the first end sleeve is provided with a first connecting buckle at the end away from the first connecting part, the second end sleeve is provided with a second connecting buckle at the end away from the second connecting part, the spliced ​​sleeve is provided with a third connecting buckle at one end, and a first connecting hole for connecting to the first connecting buckle at the other end, and the tail sleeve is provided with a second connecting hole connected to the second connecting buckle or the third connecting buckle.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. The detachable grouting sleeve used for tunnel surrounding rock support provided by the present invention is formed by sequentially connecting the first end sleeve, the splicing sleeve and the tail sleeve to form a primary grouting sleeve, and grouting and anchoring the deeper rock mass is performed, and the second end sleeve and the tail sleeve are connected to form a secondary grouting sleeve, and grouting and anchoring the shallow rock mass is performed. The primary grouting sleeve and the secondary grouting sleeve of different lengths are formed by splicing different parts, which can provide an application basis for applying multiple pre-tightening forces and strengthening the support effect at tunnel surrounding rocks of different depths; at the same time, its component structure is simple, the production and use costs are low, and different parts can be detached, spliced ​​and reused, and the scope of application is wide.

[0018] 2. The detachable grouting casing used for tunnel surrounding rock support provided by the present invention has a seepage channel that penetrates the tail casing on the first end casing, the spliced ​​casing and the second end casing. A piston assembly for feedback of grouting conditions is provided in the seepage channel. When the slurry is full, the slurry enters the seepage channel and pushes the piston assembly to move. The operator can easily and accurately know the time when the slurry is filled through the moving state of the piston assembly, thereby improving construction efficiency.

Brief Description of the Drawings

[0019] Figure 1 It is a structural schematic diagram of the foundation support structure of an embodiment of the present invention.

[0020] Figure 2 It is a structural schematic diagram of the combination of the foundation support structure and the primary grouting sleeve according to an embodiment of the present invention.

[0021] Figure 3 It is a structural schematic diagram of the combination of the foundation support structure and the secondary grouting sleeve according to an embodiment of the present invention.

[0022] Figure 4 It is a structural schematic diagram of the main support structure of an embodiment of the present invention.

[0023] Figure 5 It is a cross-sectional view of an anchor rod and an anchor cable anchor rod fixing assembly according to an embodiment of the present invention.

[0024] Figure 6 It is a three-dimensional diagram of the main support structure of an embodiment of the present invention.

[0025] Figure 7 Schematic diagram of the structure of the first baffle according to an embodiment of the present invention.

[0026] Figure 8 Schematic diagram of the structure of the third baffle according to an embodiment of the present invention.

[0027] Fig. 9 The structure of the second baffle of the embodiment of the present invention is shown in FIG. Figure 1 .

[0028] Fig.10 The structure of the second baffle of the embodiment of the present invention is shown in FIG. Figure 2 .

[0029] Fig.11 It is a cross-sectional view of a primary grouting sleeve according to an embodiment of the present invention.

[0030] Fig.12 The explosion of the primary grouting casing of the embodiment of the present invention Figure 1 .

[0031] Fig.13 The explosion of the primary grouting casing of the embodiment of the present invention Figure 2 .

[0032] Fig.14 It is a cross-sectional view of a secondary grouting sleeve according to an embodiment of the present invention.

[0033] Fig.15 The explosion of the secondary grouting casing of the embodiment of the present invention Figure 1 .

[0034] Fig.16 The explosion of the secondary grouting casing of the embodiment of the present invention Figure 2 . [Specific implementation method]

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Please refer to the attached Figure 1 To Attachment Fig.16 , this embodiment provides a tunnel surrounding rock support structure capable of applying pre-tightening force in a graded manner. The tunnel surrounding rock support structure capable of applying pre-tightening force in a graded manner comprises a main support structure applied to tunnel surrounding rock support and a detachable grouting sleeve applied to tunnel surrounding rock support. The tunnel surrounding rock support structure capable of applying pre-tightening force in a graded manner provided by the present invention adopts an adaptive support structure for surrounding rocks in different sections on the main support structure, and uses grouting sleeves of different lengths to perform grouting and anchoring on rock masses at different depths, thereby achieving differentiated support for rock masses with spatial differences and obtaining better support effects.

[0037] The main support structure used for tunnel surrounding rock support includes a main support structure 1, which includes a plurality of anchor cables 14 arranged side by side, and the plurality of anchor cables 14 are provided with a first baffle 11, a second baffle 12 and a third baffle 13 in sequence for dividing the surrounding rock through which the anchor cables 14 pass into four sections, and the four sections include a first section, a second section, a third section and a fourth section arranged in sequence for applying preload in stages; the first section is provided with a stirring anchor head 15 which is fixedly connected to the head end of the anchor cable 14 and is used for stirring the anchoring agent and for anchoring the head end of the anchor cable 14; the third section is provided with a plurality of reinforcement sections 16 which are connected to the second baffle 12 and the third baffle 13 and are arranged side by side with the anchor cables 14; the fourth section is provided with an anchor rod 17 and an anchor cable and anchor rod fixing assembly 18, the anchor rod 17 is arranged between the plurality of anchor cables 14, and the anchor cable and anchor rod fixing assembly 18 is arranged at the end of the anchor cable 14; by A first baffle 11, a second baffle 12 and a third baffle 13 are provided to divide the surrounding rock through which the anchor cable 14 passes into a first section, a second section, a third section and a fourth section which are provided in sequence and to which pre-tightening force can be applied in stages. In the first section, a support structure of a stirring anchor head 15 is adopted for anchoring support, so as to be applicable to anchoring support of deep intact rock masses; in the second section, an anchor cable 14 is adopted for support, so as to be applicable to anchoring support of relatively intact rock masses; in the third section, a support structure combining an anchor cable 14 with a reinforcement section 16 is adopted for support, so as to be applicable to anchoring support of relatively broken rock masses; in the fourth section, a support structure combining an anchor cable 14 with an anchor rod 17 is adopted for support, so as to be applicable to anchoring support of shallow broken rock masses; different support structures are adopted for different sections through the main support structure 1, so as to realize differentiated support for rock masses with spatial differences, which is more adaptable to anchoring of multi-layered rock masses, has high reliability, simple structure, convenient installation and good support effect.

[0038] The detachable grouting sleeve used for tunnel surrounding rock support includes a first end sleeve 21, a splicing sleeve 22, a tail sleeve 23 and a second end sleeve 31. The first end sleeve 21, the splicing sleeve 22 and the second end sleeve 31 are all provided with a grouting channel 24 that penetrates the tail sleeve 23. The tail sleeve 23 is provided with a grouting port 231, and the grouting port 231 is connected with the grouting channel 24. The first end sleeve 21, the splicing sleeve 22 and the tail sleeve 23 are connected in sequence to form the first-level grouting sleeve 2, and the second end sleeve 31 and the tail sleeve 23 are connected to form the second-level grouting sleeve 3. The first end sleeve 21 is provided with a first connecting portion 211 for connecting to the second baffle 12 in the main support structure, and the second end sleeve 31 is provided with a second connecting portion 311 for connecting to the third baffle 13 in the main support structure. The primary grouting sleeve 2 is detachably connected to the second baffle 12 for grouting the second section, and the secondary grouting sleeve 3 is detachably connected to the third baffle 13 for grouting the third section. The primary grouting sleeve 2 is formed by sequentially connecting the first end sleeve 21, the splicing sleeve 22 and the tail sleeve 23 to perform grouting and anchoring on the deeper rock mass, and the secondary grouting sleeve 3 is formed by connecting the second end sleeve 31 and the tail sleeve 23 to perform grouting and anchoring on the shallow rock mass. The primary grouting sleeve 2 and the secondary grouting sleeve 3 of different lengths are formed by splicing different components, which can provide an application basis for applying multiple pre-tightening forces to the surrounding rocks of the tunnels at different depths and strengthening the support effect; at the same time, its component structure is simple, the production and use costs are low, and the different components can be detachably spliced ​​and reused, and the scope of application is wide.

[0039] Furthermore, the first end casing 21, the splicing casing 22 and the second end casing 31 are all provided with a seepage channel 25 that is connected to the tail casing 23, and a piston assembly 26 for feedback of grouting conditions is provided in the seepage channel 25. When the slurry is full, the slurry enters the seepage channel 25 and pushes the piston assembly 26 to move. The operator can conveniently and accurately know the time when the slurry is full through the movement state of the piston assembly 26, thereby improving the construction efficiency.

[0040] Further, the piston assembly 26 includes a piston head 261 and a piston rod 262. The piston head 261 is disposed at one end of the piston rod 262 and the diameter of the piston head 261 is greater than the diameter of the piston rod 262. The diameter of the piston head 261 is equal to the diameter of the seepage channel 25, which can effectively prevent the slurry from entering the seepage channel 25. At the same time, the piston head 261 can move in the seepage channel 25 to feedback the grouting situation.

[0041] Further, the piston rod 262 in the primary grouting sleeve 2 includes a detachably connected spliced ​​piston rod 2621 and an anchor rod, and the piston rod 262 in the secondary grouting sleeve 3 is an anchor rod. The piston rod 262 in the primary grouting sleeve 2 can be composed of a spliced ​​piston rod 2621 of different lengths and an anchor rod, so as to be suitable for grouting of rock masses at different depths, and has a wide range of applications.

[0042] Furthermore, a first connection portion 211 is provided on the first end sleeve 21, one end of which is provided with a first limiting boss 212 protruding toward the inflow direction of the seepage channel 25, a first limiting baffle 213 is provided in the seepage channel 25 of the first end sleeve 21, and a first boss through hole 2121 communicating with the seepage channel 25 is provided on the first limiting boss 212. When forming the first-level grouting sleeve 2, the piston head 261 in the piston assembly 26 is placed between the first limiting boss 212 and the first limiting baffle 213 in the first end sleeve 21 to limit the movement of the piston assembly 26; during grouting, the piston head 261 is set behind the first limiting boss 212, thereby effectively limiting the piston head 261 from moving forward and disengaging from the first end sleeve 21; when the slurry is full, the slurry enters through the first boss through hole 2121 and pushes the piston head 261 to move backward, and stops moving when the piston head 261 contacts the first limiting baffle 213, thereby facilitating the operator to accurately judge the grouting situation and effectively blocking the slurry from entering the seepage channel 25.

[0043] Furthermore, the second end sleeve 31 is provided with a second connecting portion 311 at one end thereof and is provided with a second limiting boss 312 protruding toward the inflow direction of the seepage channel 25, the seepage channel 25 of the tail sleeve 23 is provided with a second limiting baffle 232, and the second limiting boss 312 is provided with a second boss through hole 3121 communicating with the seepage channel 25. When forming the secondary grouting sleeve 3, the piston head 261 in the piston assembly 26 is placed between the second limiting boss 312 in the second end sleeve 31 and the second limiting baffle 232 in the tail sleeve 23 to limit the movement stroke of the piston assembly 26; during grouting, the piston head 261 is set behind the second limiting boss 312, thereby effectively limiting the piston head 261 from moving forward and disengaging from the second end sleeve 31; when the slurry is full, the slurry enters through the second boss through hole 3121 and pushes the piston head 261 to move backward, and stops moving when the piston head 261 contacts the second limiting baffle 232, thereby facilitating the operator to accurately judge the grouting situation and effectively blocking the slurry from entering the seepage channel 25.

[0044] Furthermore, there are four grouting channels 24 and grouting ports 231, and the four grouting channels 24 are evenly distributed along the circumference of the pipe wall. The grouting direction of the grouting port 231 is perpendicular to the axial direction of the grouting channel 24, making the grouting operation more convenient. Compared with a single grouting port 231 and grouting channel 24, the grouting efficiency is higher, which is conducive to saving grouting time and accelerating the progress of the project.

[0045] Furthermore, the first connection part 211 includes a first buckle provided on the outer surface of the first end sleeve 21. When forming the primary grouting sleeve 2, the first connection part 211 is combined and fixed with the second baffle 12 in the main support structure 1 to perform grouting on the second section.

[0046] Furthermore, the second connection part 311 includes a second buckle 3111 and a limit baffle 3112 provided on the outer surface of the second end sleeve 31. When forming the secondary grouting sleeve 3, the second connection part 311 is fixedly combined with the third baffle 12 in the main support structure 1, wherein the second buckle 3111 is inserted into the third baffle 12, and the limit baffle 3112 is arranged on the rear end of the third baffle 12 to limit the forward movement of the secondary grouting sleeve 3, so that the connection between the secondary grouting sleeve 3 and the third baffle 12 is more stable and firm, which is conducive to smooth and stable grouting.

[0047] Further, the first end sleeve 21 is provided with a first connection buckle 214 at one end away from the first connection portion 211, the second end sleeve 31 is provided with a second connection buckle 313 at one end away from the second connection portion 311, the splicing sleeve 22 is provided with a third connection buckle 221 at one end, and a first connection hole 222 for connecting with the first connection buckle 214 at the other end, and the tail sleeve 23 is provided with a second connection hole 233 connected with the second connection buckle 313 or the third connection buckle 221. When forming the primary grouting sleeve 2, the first connection buckle 214 on the first end sleeve 21 is connected with the first connection hole 222 on the splicing sleeve 22, and the third connection buckle 221 on the splicing sleeve 22 is connected with the second connection hole 233 on the tail sleeve 23; when forming the secondary grouting sleeve 3, the second connection buckle 313 on the second end sleeve 31 is connected with the second connection hole 233 on the tail sleeve 23, which has a simple structure, a tight connection, and is easy to install.

[0048] Furthermore, the second baffle plate 12 is provided with a sleeve connecting groove 121 for connecting the primary grouting sleeve 2, and the sleeve connecting groove 121 is provided with a plurality of grouting through holes 124 that penetrate the second baffle plate 12 and are used for slurry to pass through. The second baffle plate 12 is provided with a clamping groove 122 that penetrates the sleeve connecting groove 121, and the side wall of the sleeve connecting groove 121 is provided with a first slideway 123 that is connected to the side wall of the clamping groove 122. When the primary grouting sleeve 2 is connected to the second baffle 12, one end of the primary grouting sleeve 2 enters the sleeve connecting groove 121. At the same time, the first connecting portion 211 on the primary grouting sleeve 2 is combined with the card slot 122, and the primary grouting sleeve 2 is rotated to make the grouting channel 24 of the primary grouting sleeve 2 face the grouting through hole 124 in the second baffle 12, so as to ensure that the slurry enters the second section from the grouting channel 24 of the primary grouting sleeve 2 through the grouting through hole 124 in the second baffle 12, so as to grout and anchor the second section, and at the same time make the connection between the primary grouting sleeve 2 and the second baffle 12 more stable.

[0049] Furthermore, a seepage flow hole 125 is provided in the casing connection groove 121, and a plurality of the grouting through holes 124 are evenly and equidistantly arranged along the outer periphery of the seepage flow hole 125. In this embodiment, the number of the grouting through holes 124 and the grouting channel 24 are both 4, and the grouting efficiency is higher compared with a single grouting channel 24 and a grouting through hole 124; at the same time, in this embodiment, a seepage flow hole 125 is provided on the second baffle 12, which is opposite to the seepage channel 25 in the primary grouting casing 2, which is conducive to providing a circulation channel for excess slurry to flow into the seepage channel 25.

[0050] Furthermore, the third baffle 13 is provided with a sleeve through hole 131 for allowing the primary grouting sleeve to pass through, and a clamping hole 132 that penetrates the sleeve through hole 131 and is used to connect the secondary grouting sleeve, and a second slideway 133 that is connected to the clamping hole 132 is provided on the side wall of the sleeve through hole 131. When the primary grouting sleeve 2 is connected to the second baffle 12, the primary grouting sleeve 2 passes through the sleeve through hole 131 in the third baffle 13, thereby being connected to the second baffle 12 at the front end; when the secondary grouting sleeve 3 is connected to the third baffle 13, one end of the secondary grouting sleeve 3 enters the sleeve through hole 131, and at the same time, the second buckle 3111 on the secondary grouting sleeve 3 is combined with the clamping hole 132, and the limiting baffle 3112 on the secondary grouting sleeve 3 is abutted against the rear end of the third baffle 13, and the secondary grouting sleeve 3 is rotated, so that the secondary grouting sleeve 3 forms a more stable connection with the third baffle 13, and the slurry enters the third section from the grouting channel 24 of the secondary grouting sleeve 3 to grout and anchor the third section.

[0051] Furthermore, the length of the first slideway 123 is one quarter of the circumference of the side wall of the sleeve connecting groove 121; the length of the second slideway 133 is one quarter of the circumference of the side wall of the sleeve through hole 131. Figure 8 and Fig. 9 As shown, the number of the card slots 122 and the first slide 123 in the second baffle 12 are both two, the number of the card holes 132 and the second slide 133 in the third baffle 13 are both two, and the two first slides 123 and the two second slides 133 are rotationally symmetrical. During construction operations, it is only necessary to rotate the first grouting sleeve 2 or the second grouting sleeve 3 90 degrees to achieve connection with the second baffle 12 or the third baffle 13. The structure is simple and the operation is convenient.

[0052] Furthermore, there are four anchor cables 14 and four reinforcement sections 16, which are arranged at intervals, and each anchor cable 14 is wound with four high-strength steel strands. By combining the anchor cables 14 with the reinforcement sections 16, and arranging the anchor cables 14 and the reinforcement sections 16 at intervals, the force is more uniform, which is conducive to achieving a better support effect.

[0053] Furthermore, the stirring anchor head 15 includes a stirring head baffle 151 and stirring rods 152 disposed at both ends of the stirring head baffle 151. Figure 6 As shown, the stirring rods 152 are evenly arranged at both ends of the stirring head baffle 151, which has a simple structure and a good stirring and anchoring effect.

[0054] Furthermore, the anchor rod 17 is a hollow structure and has a plurality of anchor rod through holes 171 for slurry to flow on the side wall. The end of the anchor rod 17 close to the third baffle 13 is provided with a piston 172, and the other end is provided with a slurry stopper 173. By combining the support of the anchor rod 17 and the anchor cable 14, a better support effect is achieved. In this embodiment, when the first-level grouting is performed on the second section, the anchor rod 17 is spliced ​​with the spliced ​​piston rod 2621 to form a piston rod 262 for the first-level grouting sleeve 2. When the second-level grouting is performed on the third section, the anchor rod 17 can be used as the piston rod 262, which is conducive to improving the utilization rate of the anchor rod.

[0055] Furthermore, the anchor cable and anchor bolt fixing assembly 18 comprises an anchor cable pad 181 and an anchor cable nut 182 for fixing the anchor cable 14, and an anchor cable pad 183 and an anchor cable nut 184 for fixing the anchor cable 17 are provided on the anchor cable pad 181, and an anchor cable nut groove 1831 for the anchor cable nut 182 to be embedded is provided on one end of the anchor cable pad 183 close to the anchor cable pad 181. The anchor cable pad 181 is provided with through holes for the anchor cable 14 and the anchor cable 17 to pass through respectively, and the anchor cable 14 is fixed by the anchor cable pad 181 and the anchor cable nut 182, and the anchor cable pad 183 is installed behind the anchor cable pad 181, so that the anchor cable 17 passes through the anchor cable pad 181 and the anchor cable pad 183 at the same time, enters the fourth section and supports together with the anchor cable 14, and finally the anchor cable 17 is fixed by the anchor bolt 184, so that the main support structure 1 is more stable and firm.

[0056] The tunnel surrounding rock support method capable of applying graded pre-tightening force using the tunnel surrounding rock support structure capable of applying graded pre-tightening force comprises the following steps:

[0057] Step 1: Drill a hole and divide the rock mass into the first section, the second section, the third section and the fourth section according to the rock mass fragmentation in the hole.

[0058] Among them, the first section is a deep complete rock mass, marked as X1 meters, the second section is a relatively complete rock mass, marked as X2 meters, the third section is a relatively broken rock mass, marked as X3 meters, and the fourth section is a shallow broken rock mass, marked as X4 meters. The length of the anchor cable and the relative positions of the first baffle 11, the second baffle 12 and the third baffle 13 on the anchor cable 14 are determined according to X1, X2, X3, and X4. The first baffle 11, the second baffle 12, the third baffle 13, and the stirring anchor head 15 are welded to the corresponding positions of the anchor cable 14 to form a foundation support structure.

[0059] Step 2: Anchoring of the first section: Place the anchoring agent into the first section, extend the foundation support structure along the channel, and rotate and stir to allow the stirring anchor head 15 at the head end of the foundation support structure to be fully mixed and bonded with the anchoring agent. After the anchoring agent solidifies, apply the first preload force to the anchor cable 14.

[0060] Step 3: Anchoring of the second section: Extend the first-level grouting sleeve along the hole and combine it with the second baffle 12 in the foundation support structure, grout the second section, and after the slurry solidifies, withdraw the first-level grouting sleeve 2 and apply a second pre-tightening force to the anchor cable 14. During grouting, when the piston head in the piston assembly 26 moves to the first limit baffle 213, stop grouting.

[0061] Step 4: Anchoring of the third section: extend the secondary grouting sleeve 3 along the channel and combine it with the third baffle 13 in the foundation support structure, fill the third section with slurry, and after the slurry solidifies, withdraw the secondary grouting sleeve 3 and apply a third pre-tightening force to the anchor cable 14; wherein, during grouting, stop grouting when the piston head in the piston assembly 26 moves to the second limit baffle 232.

[0062] Step 5: Anchoring of the fourth section: install the anchor pad 181 at the end of the anchor cable 14, place the anchoring agent along the channel to the rear end of the third baffle 13 in the foundation support structure, extend the anchor rod 17 along the anchor pad 181 and rotate and stir to make the end of the anchor rod 17 and the anchoring agent fully mixed and bonded, after the anchoring agent solidifies, install the anchor pad 183, fill the fourth section along the anchor rod 17 with slurry, after the slurry solidifies, apply the fourth preload to the anchor rod 17; combine the anchor rod 17 and the anchor cable anchor fixing assembly 18 with the foundation support structure to finally form the main support structure 1.

[0063] The tunnel surrounding rock support method with graded preload provided in the present embodiment divides the rock mass into four sections according to the spatial differences of the rock mass, and adopts different support structures and support methods for different sections, so as to achieve differentiated support for the rock mass with spatial differences. The present method not only adopts a support structure combining anchor rods and anchor cables, but also adopts a method combining anchoring with anchoring agent and grouting anchoring, which is more suitable for the construction environment of deep and high-stress tunnels, and is more reliable than the ordinary single anchoring support method of anchor rods or anchor cables and the single anchoring agent anchoring or grouting anchoring, and the anchoring effect is more obvious.

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A detachable grouting casing used for tunnel surrounding rock support, characterized by: The invention comprises a first end casing (21), a splicing casing (22), a tail casing (23) and a second end casing (31); the first end casing (21), the splicing casing (22) and the second end casing (31) are all provided with a grouting channel (24) which is in communication with the tail casing (23); the tail casing (23) is provided with a grouting port (231); the grouting port (231) is in communication with the grouting channel (24); the first end casing (21), the splicing casing (22) and the tail casing (23) are sequentially connected to form a primary grouting casing (2), the second end casing (31) and the tail casing (23) are connected to form a secondary grouting casing (3), the first end casing (21) is provided with a first connecting portion (211) for connecting to a second baffle in the main support structure, and the second end casing (31) is provided with a second connecting portion (311) for connecting to a third baffle in the main support structure; the main support structure comprises a plurality of anchor cables arranged side by side, and the plurality of anchor cables are provided with a first baffle, a second baffle and a third baffle in sequence for dividing the surrounding rock through which the anchor cables pass into four sections; The first end casing (21), the splicing casing (22) and the second end casing (31) are all provided with a seepage channel (25) that is in communication with the tail casing (23); the seepage channel (25) of the first end casing (21) and the seepage channel (25) of the second end casing (31) are provided with a piston assembly (26) for feedback of grouting conditions; The piston assembly (26) comprises a piston head (261) and a piston rod (262); the piston head (261) is arranged at one end of the piston rod (262) and the diameter of the piston head (261) is larger than the diameter of the piston rod (262); the diameter of the piston head (261) is equal to the diameter of the seepage channel (25); The first end sleeve (21) is provided with a first connection portion (211) at one end thereof, and is provided with a first limiting boss (212) protruding in the inflow direction of the seepage channel (25); the seepage channel (25) of the first end sleeve (21) is provided with a first limiting baffle (213) opposite to the first limiting boss (212); the first limiting boss (212) is provided with a first boss through hole (2121) communicating with the seepage channel (25); When forming the primary grouting sleeve (2), the piston head (261) in the piston assembly (26) is placed between the first limiting boss (212) and the first limiting baffle (213) in the first end sleeve (21) to limit the movement stroke of the piston assembly (26).

2. The detachable grouting sleeve for tunnel surrounding rock support according to claim 1 is characterized in that: The second end sleeve (31) is provided with a second connection portion (311) at one end thereof, and is provided with a second limiting boss (312) protruding in the inflow direction of the seepage channel (25); a second limiting baffle (232) is provided in the seepage channel (25) of the tail sleeve (23); and the second limiting boss (312) is provided with a second boss through hole (3121) communicating with the seepage channel (25); When forming the secondary grouting sleeve (3), the piston head (261) in the piston assembly (26) is placed between the second limiting boss (312) in the second end sleeve (31) and the second limiting baffle (232) in the tail sleeve (23) to limit the movement stroke of the piston assembly (26).

3. The detachable grouting sleeve for tunnel surrounding rock support according to claim 1 is characterized in that: The piston rod (262) in the primary grouting sleeve (2) comprises a detachably connected spliced ​​piston rod (2621) and an anchor rod, and the piston rod (262) in the secondary grouting sleeve (3) is an anchor rod.

4. The detachable grouting sleeve for tunnel surrounding rock support according to claim 1 is characterized in that: The number of the grouting channels (24) and the grouting ports (231) is four, the four grouting channels (24) are evenly distributed along the circumference of the pipe wall, and the grouting direction of the grouting ports (231) is perpendicular to the axial direction of the grouting channels (24).

5. The detachable grouting sleeve for tunnel surrounding rock support according to claim 1 is characterized in that: The first connecting portion (211) comprises a first buckle provided on the outer surface of the first end sleeve (21).

6. The detachable grouting sleeve for tunnel surrounding rock support according to claim 1 is characterized in that: The second connection portion (311) comprises a second buckle (3111) and a limit baffle (3112) provided on the outer surface of the second end sleeve (31).

7. The detachable grouting sleeve for tunnel surrounding rock support according to claim 1 is characterized in that: A first connection buckle (214) is provided on one end of the first end sleeve (21) away from the first connection portion (211), a second connection buckle (313) is provided on one end of the second end sleeve (31) away from the second connection portion (311), a third connection buckle (221) is provided on one end of the splicing sleeve (22), and a first connection hole (222) for connecting to the first connection buckle (214) is provided on the other end, and a second connection hole (233) for connecting to the second connection buckle (313) or the third connection buckle (221) is provided on the tail sleeve (23).

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