Roadway advance support device and roadway advance reinforcing method

Abstract

The application provides a roadway advanced support device and a roadway advanced reinforcement method, the support device comprises a support arch, the support arch comprises an upper support and a lower vertical support, the lower vertical supports are arranged below the two sides of the upper support; a cavity outer anchor rod is inserted into the upper support; an inner anchor rod is inserted into the cavity outer anchor rod; a column foot hole is arranged at the bottom of the lower vertical support, and a column foot connecting rod is inserted into the column foot hole; the advanced reinforcement method realizes the advanced support of the next roadway section through multiple steps; the inner anchor rod with a grouting through hole is inserted into the cavity outer anchor rod, the advanced grouting and the advanced support before the blasting and excavation of the next roadway section are realized, the lower pressure of the surrounding rock of the newly excavated roadway section is conducted to the surrounding rock of the roadway section with the installed support arch as the fulcrum and the anchor rod as the lever, the force balance is realized, and the stability of the advanced support roadway section is maintained.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel reinforcement construction, and more specifically, relates to a tunnel advance support device and a tunnel advance reinforcement method. Background Art

[0002] It is very difficult to excavate and support tunnels in surrounding rock with unstable roofs or developed joints and fissures. This type of surrounding rock has poor self-stabilization ability and short self-stabilization time, making both self-support and advance support difficult. Traditional advance support methods mostly involve inserting anchor rods or anchor cables obliquely upward into the unstable rock mass to tightly connect the unstable rock mass with the stable rock mass. This advance support method is less effective for surrounding rock with developed joints and fissures, especially for the surrounding rock at the foot of the oblique anchor rod, which has almost no protection and poses a great safety hazard. In addition, this method often requires a very long anchor rod or anchor cable, which also increases the support cost. Moreover, most existing support methods separate advance support and the support of the tunnel itself into two support methods or modes. The support of a section of the tunnel often requires multiple machines and multiple professional operators, which reduces support efficiency and is not conducive to the coordination and unification of tunnel support work. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a support device and a method for advance reinforcement that can be easily operated in unstable or well-jointed rock tunnels, is efficient and economical, and can not only provide good support for the current tunnel section, but also provide effective advance support for the next tunnel section.

[0004] To achieve the above object, the present invention adopts the following technical solution: a tunnel advance support device, comprising a support arch frame, the support arch frame comprising an upper support and a lower vertical support, and lower vertical supports are provided on both sides below the upper support;

[0005] The upper bracket is composed of an arc-shaped bracket section at the top and straight bracket sections at the lower ends of both sides of the arc-shaped bracket section; the arc-shaped bracket section and the straight bracket section are respectively provided with a No. 1 circular hole and a No. 2 circular hole, each of which is inserted with an external cavity anchor rod; the internal anchor rod is inserted into the internal cavity anchor rod located in the No. 1 circular hole;

[0006] A No. 3 round hole is opened on the lower vertical bracket, and a cavity outer anchor rod is inserted into the No. 3 round hole; a column foot hole is opened at the bottom of the lower vertical bracket, and a column foot connecting rod is inserted into the column foot hole.

[0007] Furthermore, both ends of the inner anchor rod are open and the interior is hollow, and the surface of the inner anchor rod is provided with staggered grouting holes, which are communicated with the internal cavity of the inner anchor rod.

[0008] Furthermore, a long bolt is provided between the lower vertical support and the straight support section, and an adjusting nut is sleeved on the long bolt. When the adjusting nut is turned, the adjusting nut rises along the long screw rod to lift the upper support upward, and the upper support moves upward to tighten the tunnel roof to play a supporting role.

[0009] A tunnel advance reinforcement method comprises the following steps:

[0010] S1. Support the tunnel section: First, determine the positions of two sets of support arches in the tunnel section that has been excavated but not yet supported. Place two sets of four column foot pads at the corners of the locations where the support arches are pre-installed. Install a lower vertical support on each column foot pad, for a total of two sets of four lower vertical supports.

[0011] Install two right-angle washers with right angles on both sides at the upper end of each set of lower vertical supports and the lower end of the corresponding upper supports to be installed. Use short screw and nut sets to fix the right-angle washers to the ends of the upper supports and lower vertical supports respectively.

[0012] A long screw is provided between the lower ends of both sides of the upper bracket and the corresponding lower vertical brackets. An adjusting nut is sleeved on the long screw, and the adjusting nut is first screwed to a lower position on the long screw;

[0013] Use a large nut to securely connect the lower end of the long screw to the right-angle washer at the end of the lower vertical bracket; insert the upper end of the long screw into the bolt hole of the right-angle washer at the end of the upper bracket;

[0014] Twist the adjusting nut to move it upward along the long screw rod. The adjusting nut rises along the long screw rod and gradually lifts up the upper bracket, so that the upper bracket presses against the tunnel roof to play a supporting role.

[0015] After the upper support is tightened against the tunnel roof, a large nut is put on the upper end of the long screw, and the large nut is tightened to fix the upper end of the long screw with the right-angle gasket at the end of the upper support, thus completing the assembly of the support arch;

[0016] Then, insert the column foot connecting rod into the column foot hole at the bottom of the lower vertical support, and connect the front and rear support arch frames from the bottom;

[0017] S2. Perform advance support for the next tunnel section: insert an external anchor rod into the No. 1 circular hole of the upper support arch installed in this tunnel section, and connect the front and rear support arches from the top;

[0018] The rock mass to be blasted is positioned for advanced support drilling. After positioning, the rock drill drills grouting holes on the rock wall of the rock mass to be blasted according to the positioning position;

[0019] Then, an inner anchor rod with grouting holes distributed on the surface and hollow inside is inserted into the outer anchor rod of the cavity. The front end of the inner anchor rod is flush with the front end of the outer anchor rod, and the rear end of the inner anchor rod penetrates into the grouting hole on the rock wall. Then, a grouting machine injects grouting material from the front end of the inner anchor rod into the grouting hole on the rock wall to seal the surrounding rock cracks. Under the advanced support of the inner anchor rod and the self-stabilization protection of the closed surrounding rock, blasting and slag removal of the next tunnel section are carried out. After the slag removal is completed, the installation of the column foot gasket, lower vertical bracket, right-angle gasket and long screw of the next tunnel section is started.

[0020] S3. Complete the support work of the current tunnel section: After the column foot gaskets, lower vertical brackets, right-angle gaskets, and long screws of the next tunnel section are installed, move the inner anchor rod toward the current tunnel section, retract the inner anchor rod into the cavity outer anchor rod of the current tunnel section, and make the front end of the inner anchor rod enter the cavity outer anchor rod at the corresponding position in the previous tunnel section, thereby connecting the cavity outer anchor rod of the current tunnel section with the cavity outer anchor rod of the previous tunnel section;

[0021] Insert the external anchor rod into the No. 2 circular hole of the straight support section of the upper support, insert the external anchor rod into the No. 3 circular hole of the lower vertical support, and connect the front and rear sets of support arches from the side to complete the support work of this tunnel section.

[0022] S4. Support the next tunnel section: repeat the operation in step S1 to install the upper bracket in the next tunnel section; repeat the operations in steps S2 and S3 to perform advance support on the tunnel section located behind the next tunnel section and complete the support work of the next tunnel section.

[0023] Furthermore, in order to ensure the smooth completion of the tunnel advance reinforcement work, the tunnel blasting is required to have a blasting footage of the length of two tunnel sections, and the length of a single tunnel section is about 1-2m.

[0024] Furthermore, in order to ensure the safety of tunnel installation as much as possible, the support work of this tunnel section overlaps with the support work of the next tunnel section in time. Specifically, the blasting and slag removal of the next tunnel section is carried out under the advanced support protection of the inner anchor rod of this tunnel section; after the slag removal is completed, the column foot gaskets, right-angle arch frames, right-angle gaskets and long screws of the next tunnel section are installed under the advanced support protection of the inner anchor rod of this tunnel section; after the above support work of the next tunnel section is completed, the inner anchor rod of this tunnel section is retracted into the outer anchor rod of the cavity to a certain distance, so that the inner anchor rod returns to the current tunnel section, and the advanced support is completed;

[0025] The upper support is quickly installed in the next tunnel section, and the advance support work of the subsequent tunnel section is quickly carried out under the protection of the upper support.

[0026] Furthermore, the length of the anchor rod outside the cavity is approximately the length of two tunnel sections; the inner anchor rod is approximately 20%-40% longer than the anchor rod outside the cavity; and the outer diameter of the inner anchor rod is the same as the inner diameter of the anchor rod outside the cavity.

[0027] Furthermore, the column foot connecting rod includes a cavity portion and a solid portion; the outer diameter of the cavity portion is approximately the diameter of the column foot hole, and the length of the cavity portion is approximately the length of two tunnel sections;

[0028] The outer diameter of the solid portion is the same as the inner diameter of the cavity portion, and the length of the solid portion is approximately the length of one tunnel section.

[0029] Furthermore, the length of the lower vertical support is about 1m; the length of the long screw is about 0.5-0.8m;

[0030] The single side length of the right-angle gasket is about 10 cm, and each side has at least two circular holes with a diameter of about 2 cm; the straight bracket section and the lower vertical bracket are also provided with at least two circular holes with a diameter of about 2 cm at the end, which facilitates the short screw and nut set to tighten and fix the right-angle gasket to the straight bracket section and the lower vertical bracket respectively.

[0031] Furthermore, the grouting material is a silicate-modified polyurethane material, which can quickly generate high-strength polymers after grouting, and quickly cement the original loose and discontinuous rock mass into a continuous and complete load-bearing body.

[0032] Compared with the prior art, the tunnel advance support device and tunnel advance reinforcement method of the present invention have the following beneficial effects:

[0033] 1. The advance support device and tunnel advance reinforcement method of the present invention can support both the current tunnel section and the next tunnel section, thus achieving coordinated support of the current tunnel section and the next tunnel section.

[0034] 2. The advance support device and tunnel advance reinforcement method of the present invention can adjust the height of the upper support according to the specific height of the tunnel section. Compared with the fixed arch support in the prior art, the present invention can make the upper support close to the tunnel roof, thereby enhancing the support effect of the support device.

[0035] 3. The advance support device and tunnel advance reinforcement method of the present invention connects each set of support arches into a whole by using the column foot connecting rods at the bottom of the lower vertical support and the cavity external anchor rods and internal anchor rods at the top of the upper support. This can fully exert the support function of the entire support arch group and enhance the ability to resist surrounding rock pressure and deformation.

[0036] 4. The advance support device and advance tunnel reinforcement method of the present invention, when performing advance support on the next tunnel section, uses the inner anchor rod to bear the pressure from the upper surrounding rock, and transmits the pressure along the anchor rod outside the cavity to the support arch installed in the current tunnel section, and then transmits it to the surrounding rock at the top of the current tunnel section. The support arch serves as a fulcrum and the anchor rod serves as a lever, so that the downward pressure of the surrounding rock of the newly excavated tunnel section is borne by the surrounding rock of the tunnel section where the support arch is installed, thereby balancing the surrounding rock pressure of different sections and maintaining the stability of the advance supported tunnel section.

[0037] 5. The silicate-modified polyurethane polymer material grouting used in the advance support device and the tunnel advance reinforcement method of the present invention has high solidification strength. The compressive and shear strengths of the surrounding rock after sealing are higher than those of the original rock, which can effectively ensure the stability of the surrounding rock at the top of the tunnel; the reaction time is short, which does not delay the support construction period, and does not produce any toxic and harmful substances, and does not react with water. It is a new type of grouting material that is efficient, environmentally friendly and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 This is a front view of the tunnel advance support device after installation of the present invention.

[0040] Figure 2 This is a top view of the tunnel advance support device of the present invention after the tunnel section support is installed.

[0041] Figure 3 The top view of the tunnel advance support device of the present invention completing the advance support of the next tunnel section.

[0042] Figure 4 This is a partial schematic diagram of the installation of the long screw and right-angle gasket of the tunnel advance support device of the present invention.

[0043] Figure 5 It is a schematic structural diagram of the cavity outer anchor rod and inner anchor rod of the tunnel advance support device of the present invention.

[0044] Figure 6 It is a structural schematic diagram of the column foot connecting rod of the tunnel advance support device of the present invention.

[0045] Figure 7 It is a structural schematic diagram of the right-angle gasket of the tunnel advance support device of the present invention.

[0046] Explanation of symbols in the figure:

[0047] 1. Upper bracket; 2. Lower vertical bracket; 3. Column foot gasket; 4. Right-angle gasket; 5. Short screw and nut set; 6. Long bolt; 7. Long screw; 8. Cavity external anchor rod; 9. Internal anchor rod; 10. Column foot connecting rod;

[0048] 11. Arc-shaped bracket section; 12. Straight bracket section; 13. Round hole No. 1; 14. Round hole No. 2;

[0049] 21. No. 3 circular hole; 22. Column foot hole; 41. Bolt hole; 61. Adjusting nut; 91. Grouting hole; 92. Rock mass to be blasted; 101. Cavity; 102. Solid part. DETAILED DESCRIPTION

[0050] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] like Figure 1 As shown, a tunnel advance support device includes a support arch frame, the support arch frame includes an upper support 1 and a lower vertical support 2, and lower vertical supports are provided on both sides below the upper support;

[0052] The upper support 1 is composed of an arc-shaped support section 11 at the top and straight support sections 12 at the lower ends of both sides of the arc-shaped support section; a first circular hole 13 and a second circular hole 14 are respectively formed on the arc-shaped support section and the straight support section, and an outer cavity anchor rod 8 is inserted into each of the first and second circular holes; an inner anchor rod 9 is inserted into the inner cavity anchor rod located in the first circular hole;

[0053] A third circular hole 21 is provided on the lower vertical support 2 , into which the outer cavity anchor rod 8 is inserted; a column foot hole 22 is provided at the bottom of the lower vertical support 2 , into which the column foot connecting rod 10 is inserted.

[0054] like Figure 4 As shown, a long bolt 6 is provided between the lower vertical support 2 and the straight support section 12, and an adjusting nut 61 is sleeved on the long bolt 6. When the adjusting nut 61 is screwed, the adjusting nut rises along the long screw rod 7 to lift the upper support 1 upward, and the upper support 1 moves upward to press against the tunnel roof to play a supporting role.

[0055] like Figure 1-Figure 7 As shown, a tunnel advance reinforcement method includes the following steps:

[0056] S1. Support the tunnel section: first determine the positions of two groups of support arches in the tunnel section that has been excavated but not yet supported, and place two groups of four column foot gaskets at the corners of the positions where the support arches are pre-installed. Install a lower vertical bracket 2 on each column foot gasket 3, for a total of two groups of four lower vertical brackets; the length of the lower vertical bracket 2 is about 1m; the column foot gasket is used to increase the bottom force-bearing area of ​​the support device.

[0057] Two right-angled washers 4, each with right angles, are installed at the top and bottom of each set of lower vertical supports and the corresponding lower end of the upper support 1 to be installed. These washers are secured to the ends of the upper and lower vertical supports, respectively, using short screw and nut assemblies 5. Each side of each washers 4 is approximately 10 cm long and has at least two circular holes with a diameter of approximately 2 cm on each side. The ends of the straight support segments 12 and lower vertical support 2 also have at least two circular holes with a diameter of approximately 2 cm, allowing the short screw and nut assemblies to tighten and secure the washers 4 to the straight support segments 12 and lower vertical support 2, respectively.

[0058] A long screw rod 7 is provided between the lower ends of both sides of the upper bracket 1 and the corresponding lower vertical bracket 2. The length of the long screw rod 7 is about 0.5-0.8m. An adjusting nut 61 is sleeved on the long screw rod 7, and the adjusting nut is first screwed to a lower position on the long screw rod 7.

[0059] The lower end of the long screw rod 7 is fixedly connected to the right-angle washer at the end of the lower vertical bracket with a large nut; the upper end of the long screw rod 7 is inserted into the bolt hole of the right-angle washer at the end of the upper bracket.

[0060] The adjusting nut 61 is screwed to move upward along the long screw 7. The adjusting nut 61 rises along the long screw 7 and gradually lifts the upper bracket 1 upward, thereby making the upper bracket 1 press against the tunnel roof to play a supporting role.

[0061] After the upper bracket 1 is tightened against the tunnel roof, a large nut is put on the upper end of the long screw 7, and the large nut is tightened to fix the upper end of the long screw 7 to the right-angle gasket at the end of the upper bracket, thereby completing the assembly of the support arch.

[0062] Then, the column foot connecting rod 10 is inserted into the column foot hole 22 at the bottom of the lower vertical support, and the column foot connecting rod 10 connects the front and rear support arch frames from the bottom.

[0063] The column base connector 10 consists of a hollow portion 101 and a solid portion 102. The outer diameter of the hollow portion is approximately the diameter of the column base hole 22, and its length is approximately the length of two tunnel sections. The outer diameter of the solid portion is the same as its inner diameter, and its length is approximately the length of one tunnel section. The hollow portions of the column base connectors for adjacent tunnel sections are connected end to end, with the ends of the solid portions inserted into adjacent hollow portions, connecting the support arches from the bottom.

[0064] S2. Perform advance support on the next tunnel section: insert the cavity outer anchor rod 8 into the No. 1 circular hole 13 of the upper bracket of the support arch installed in this tunnel section, and connect the front and rear groups of support arches from the top.

[0065] The rock mass to be blasted 92 is positioned for advanced support drilling. After positioning, a rock drill drills grouting holes on the rock wall of the rock mass to be blasted according to the positioning position.

[0066] Then, an inner anchor rod 9 with grouting holes 91 distributed on the surface and hollow inside is inserted into the outer anchor rod 8 in the cavity. The front end of the inner anchor rod is flush with the front end of the outer anchor rod, and the rear end of the inner anchor rod penetrates into the grouting hole on the rock wall. Then, a grouting machine injects grouting material from the front end of the inner anchor rod into the grouting hole on the rock wall to seal the surrounding rock cracks.

[0067] The grouting material is a polymer, primarily composed of silicate-modified polyurethane. After grouting, it rapidly forms a high-strength aggregate, rapidly cementing the previously loose, discontinuous rock mass into a continuous, complete, load-bearing structure. The grouting results in higher compressive and shear strengths than the original rock, ensuring the stability of the surrounding rock at the top of the tunnel.

[0068] The inner anchor rod 9 is open at both ends and hollow inside. Grouting holes 91 are arranged in a staggered pattern on the surface of the inner anchor rod 9, and the grouting holes 91 are connected to the inner cavity of the inner anchor rod. When the grouting machine injects grout into the grouting hole in the rock wall through the inner anchor rod, the grouting material does not accumulate only at the rear end of the inner anchor rod. Instead, the grouting material is evenly injected into the grouting hole in the rock wall through the staggered and staggered grouting holes on the inner anchor rod, without any dead angles. This makes the grouting of the grouting hole more uniform, covers a larger area, and achieves better grouting effect.

[0069] The outer anchor rod of the cavity is approximately the length of two tunnel sections; the inner anchor rod is longer than the outer anchor rod, approximately 20%-40% longer than the outer anchor rod of the cavity. The outer diameter of the inner anchor rod is the same as the inner diameter of the outer anchor rod of the cavity. Through the mechanical design of the inner and outer diameter tolerances of the outer and inner anchor rods, the inner anchor rod can move relative to the outer anchor rod, but the gap between the two cannot allow grouting material to flow into the outer anchor rod.

[0070] The inner anchor rods bear the pressure from the upper surrounding rock, and the blasting and slag removal of the next tunnel section are carried out under the advance support of the inner anchor rods and the self-stabilization protection of the closed surrounding rock; to ensure the smooth completion of the tunnel advance reinforcement work, the tunnel blasting is required to be the length of two tunnel sections at a time, and the length of a single tunnel section is about 1-2m.

[0071] After the slag is discharged, the installation of the column foot gasket, lower vertical bracket, right-angle gasket and long screw 7 of the next tunnel section begins.

[0072] S3. Complete the support work of the current tunnel section: After the column foot gasket, lower vertical bracket, right-angle gasket and long screw 7 of the next tunnel section are installed, move the inner anchor rod 9 toward the current tunnel section, retract the inner anchor rod into the cavity outer anchor rod of the current tunnel section, and make the front end of the inner anchor rod enter the cavity outer anchor rod of the corresponding position in the previous tunnel section, thereby connecting the cavity outer anchor rod of the current tunnel section with the cavity outer anchor rod of the previous tunnel section;

[0073] Insert the external anchor rod into the No. 2 circular hole 14 of the straight support section of the upper support, and insert the external anchor rod into the No. 3 circular hole 21 of the lower vertical support, and connect the front and rear groups of support arch frames from the side to avoid side deformation of the support device; the support work of this tunnel section is completed.

[0074] S4. Support the next tunnel section: repeat the operation in step S1 to install the upper bracket in the next tunnel section; repeat the operations in steps S2 and S3 to perform advance support on the tunnel section located behind the next tunnel section and complete the support work of the next tunnel section.

[0075] In order to ensure the safety of tunnel installation as much as possible, the support work of this tunnel section overlaps with the support work of the next tunnel section in time. Specifically, the blasting and slag removal of the next tunnel section is carried out under the advance support protection of the inner anchor rod of this tunnel section; after the slag removal is completed, the column foot gasket, right-angle arch frame, right-angle gasket and long screw 7 of the next tunnel section are installed under the advance support protection of the inner anchor rod of this tunnel section; after the above support work of the next tunnel section is completed, the inner anchor rod of this tunnel section is retracted to a certain distance inside the outer anchor rod of the cavity, so that the inner anchor rod returns to this tunnel section, and the advance support is completed; the upper bracket is quickly installed in the next tunnel section, and the advance support work of the subsequent tunnel section is quickly carried out under the protection of the upper bracket.

[0076] The present invention can solve the problems of poor support effect, high support cost and low support efficiency when performing advance support for tunnel excavation in surrounding rocks with unstable roofs or developed joints and fissures. By inserting the outer anchor rod of the cavity and the inner anchor rod with grouting holes into the No. 1 circular hole 13 of the arc-shaped support section, advance grouting and advance support before blasting and excavation of the next tunnel section are achieved. At the same time, the support arch is used as a fulcrum and the anchor rod is used as a lever to transmit the downward pressure of the surrounding rock of the newly excavated tunnel section to the surrounding rock of the tunnel section where the support arch has been installed, so as to balance the force and maintain the stability of the advance supported tunnel section. A set of support devices realizes the support of the current tunnel section and the advance support of the next tunnel section. The straight inner anchor rod is used for advance support, which shortens the anchor rod length requirement. The inner anchor rod is provided with staggered grouting holes to increase the grouting range. The present invention has ingenious conception, good supporting effect, low supporting cost and simple supporting work, thereby ensuring the efficiency of the supporting work.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A tunnel advance reinforcement method, implemented using a tunnel advance support device, characterized by: The tunnel advance support device comprises a support arch frame, the support arch frame comprises an upper support (1) and a lower vertical support (2), and the lower vertical supports are provided below both sides of the upper support; The upper bracket (1) is composed of an arc-shaped bracket section (11) located at the top and straight bracket sections (12) located at the lower ends of both sides of the arc-shaped bracket section; the arc-shaped bracket section and the straight bracket section are respectively provided with a No. 1 circular hole (13) and a No. 2 circular hole (14), and the No. 1 circular hole and the No. 2 circular hole are both inserted with a cavity outer anchor rod (8); the inner portion of the cavity outer anchor rod located in the No. 1 circular hole is inserted with an inner anchor rod (9); The lower vertical bracket (2) is provided with a third circular hole (21), into which the outer anchor rod (8) of the cavity is inserted; the bottom of the lower vertical bracket (2) is provided with a column foot hole (22), into which a column foot connecting rod (10) is inserted; The inner anchor rod (9) is open at both ends and hollow inside, and the surface of the inner anchor rod (9) is provided with staggered grouting holes (91), and the grouting holes (91) are connected to the inner cavity of the inner anchor rod; A long bolt (6) is provided between the lower vertical support (2) and the straight support section (12), and an adjusting nut (61) is sleeved on the long bolt (6). When the adjusting nut (61) is screwed, the adjusting nut rises along the long screw rod (7) to lift the upper support (1), and the upper support (1) moves upward to press against the tunnel roof to provide support. The tunnel advance reinforcement method comprises the following steps: S1. Support the tunnel section: first determine the positions of two sets of support arches in the tunnel section that has been excavated but not yet supported, place two sets of four column foot pads at the corners of the positions where the support arches are pre-installed, and install a lower vertical support (2) on each column foot pad (3), for a total of two sets of four lower vertical supports; Two right-angled washers (4) with right angles on both sides are installed at the upper end of each set of lower vertical supports and the lower end of the upper support (1) to be installed at the corresponding position, and the right-angled washers are fixed to the ends of the upper support and the lower vertical support respectively using short screw nut groups (5); A long screw rod (7) is provided between the lower ends of both sides of the upper support (1) and the lower vertical support (2) corresponding to the position thereof. An adjusting nut (61) is sleeved on the long screw rod (7), and the adjusting nut is first screwed to a lower position on the long screw rod (7); The lower end of the long screw rod (7) is fixedly connected to the right-angled washer at the end of the lower vertical bracket with a large nut; the upper end of the long screw rod (7) is inserted into the bolt hole of the right-angled washer at the end of the upper bracket; The adjusting nut (61) is screwed to move upward along the long screw (7), and the adjusting nut (61) rises along the long screw (7) and gradually lifts the upper bracket (1) upward, thereby making the upper bracket (1) press against the tunnel roof to play a supporting role; After the upper support (1) is tightened against the tunnel roof, a large nut is put on the upper end of the long screw (7), and the large nut is tightened to fix the upper end of the long screw (7) to the right-angled gasket at the end of the upper support, thereby completing the assembly of the support arch; Then, a column foot connecting rod (10) is inserted into the column foot hole (22) at the bottom of the lower vertical bracket, and the column foot connecting rod (10) connects the front and rear support arch frames from the bottom; S2. Perform advance support on the next tunnel section: insert the cavity outer anchor rod (8) into the No. 1 circular hole (13) of the upper bracket of the support arch installed in the tunnel section, and connect the front and rear sets of support arches from the top; Performing advanced support drilling positioning on the rock mass to be blasted (92), and after positioning, drilling a grouting hole on the rock wall of the rock mass to be blasted according to the positioning position by a rock drilling rig; Then, an inner anchor rod (9) with grouting holes (91) distributed on the surface and hollow inside is inserted into the inner cavity outer anchor rod (8), the front end of the inner anchor rod is flush with the front end of the outer anchor rod, and the rear end of the inner anchor rod is deep into the grouting hole on the rock wall, and then a grouting machine is used to inject grouting material from the front end of the inner anchor rod into the grouting hole on the rock wall to seal the surrounding rock cracks; under the advanced support of the inner anchor rod and the self-stabilization protection of the closed surrounding rock, the blasting and slag removal of the next tunnel section is carried out, and after the slag removal is completed, the installation work of the column foot gasket, the lower vertical bracket, the right-angle gasket and the long screw (7) of the next tunnel section is started; S3, completing the support work of the current tunnel section: after the column foot gasket, lower vertical bracket, right-angle gasket and long screw (7) of the next tunnel section are installed, the inner anchor rod (9) is moved in the direction of the current tunnel section, the inner anchor rod is retracted into the cavity outer anchor rod of the current tunnel section, and the front end of the inner anchor rod is made to enter the cavity outer anchor rod of the corresponding position in the previous tunnel section, thereby connecting the cavity outer anchor rod of the current tunnel section with the cavity outer anchor rod of the previous tunnel section; Insert the cavity external anchor rod into the No. 2 circular hole (14) of the straight support section of the upper support, insert the cavity external anchor rod into the No. 3 circular hole (21) of the lower vertical support, and connect the front and rear sets of support arches from the side, thus completing the support work of this tunnel section; S4. Support the next tunnel section: repeat the operation in step S1 to install the upper bracket in the next tunnel section; repeat the operations in steps S2 and S3 to perform advance support on the tunnel section located behind the next tunnel section and complete the support work of the next tunnel section.

2. The method for advanced roadway reinforcement according to claim 1, characterized in that: In order to ensure the smooth completion of the tunnel advance reinforcement work, the tunnel blasting is required to have a blasting footage of the length of two tunnel sections, and the length of a single tunnel section is 1-2m.

3. The tunnel advance reinforcement method according to claim 1, characterized in that: In order to ensure the safety of the tunnel installation as much as possible, the support work of this tunnel section overlaps with the support work of the next tunnel section in time. Specifically, the blasting and slag removal of the next tunnel section is carried out under the advanced support protection of the inner anchor rod of this tunnel section; after the slag removal is completed, the column foot gasket, right-angle arch frame, right-angle gasket and long screw (7) of the next tunnel section are installed under the advanced support protection of the inner anchor rod of this tunnel section; after the above support work of the next tunnel section is completed, the inner anchor rod of this tunnel section is retracted to a certain distance inside the outer anchor rod of the cavity, so that the inner anchor rod returns to this tunnel section, and the advanced support is completed; The upper support is quickly installed in the next tunnel section, and the advance support work of the subsequent tunnel section is quickly carried out under the protection of the upper support.

4. The method for advanced roadway reinforcement according to claim 1, characterized in that: The length of the anchor rod outside the cavity is the length of two tunnel sections; the inner anchor rod is 20%-40% longer than the anchor rod outside the cavity; the outer diameter of the inner anchor rod is the same as the inner diameter of the anchor rod outside the cavity.

5. The method for advanced roadway reinforcement according to claim 1, characterized in that: The column foot connecting rod (10) comprises a cavity portion (101) and a solid portion (102); the outer diameter of the cavity portion is the aperture of the column foot hole (22), and the length of the cavity portion is the length of two tunnel sections; The outer diameter of the solid part is the same as the inner diameter of the cavity part, and the length of the solid part is the length of one tunnel section.

6. The method for advanced roadway reinforcement according to claim 1, characterized in that: The length of the lower vertical support (2) is 1 m; the length of the long screw (7) is 0.5-0.8 m; The length of a single side of the right-angled gasket (4) is 10 cm, and each side has at least two circular holes with a diameter of 2 cm; the straight bracket section (12) and the lower vertical bracket (2) are also provided with at least two circular holes with a diameter of 2 cm at the end, so as to facilitate the short screw and nut assembly to tighten and fix the right-angled gasket (4) to the straight bracket section (12) and the lower vertical bracket (2) respectively.

7. The method for advanced roadway reinforcement according to claim 1, characterized in that: The grouting material is silicate-modified polyurethane material, which can quickly generate high-strength polymers after grouting, and quickly cement the original loose and discontinuous rock mass into a continuous and complete load-bearing body.

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