Prefabricated tunnel advanced grouting grout-stopping wall and using method

Abstract

The invention relates to an assembly type tunnel advanced grouting grout-stopping wall and a using method, the grout-stopping wall is of an arch structure on the whole, prefabricated grouting holes are distributed in the grout-stopping wall, the grout-stopping wall is divided into detachable i layers from a tunnel bottom plate to a tunnel top arch, i is larger than or equal to 1, the first layer makes contact with the tunnel bottom plate, the height of the first layer is b1, the second layer is located above the first layer, and the height of the second layer is b2, the third layer is arranged on the second layer, the height of the third layer is b3, and so on, the ith layer is arranged on the (i-1) th layer; every i layers of the grout stop wall can be divided into j detachable assembly plates. Each assembly plate is of a prefabricated reinforced concrete structure or a metal structure with certain strength, can be rapidly installed before tunnel grouting and is convenient to disassemble after grouting, the construction efficiency of a grouting wall in the tunnel advanced grouting process can be effectively improved, and the tunnel construction progress is guaranteed. Through simple maintenance or water stop rubber replacement, the water stop device can be used in next advance grouting construction and can be used for multiple times, and the tunnel construction cost can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and in particular to a prefabricated advanced grouting plugging wall for tunnels and its usage method. Background Art

[0002] During the tunnel excavation process, in sections such as encountering faults, fractured zones, fissure-developed zones, and large water inrusions, there may be risks of water inrush and mud burst, which are likely to cause significant property and personnel losses. To improve the safety of tunnel construction, it is necessary to conduct advanced grouting on the sections where there may be risks of water inrush and mud burst to reinforce the surrounding rock structure of the tunnel, improve the integrity and self-stability of the surrounding rock, and reduce the permeability of the surrounding rock. In the existing construction technology, generally, a concrete plugging wall is formed by on-site formwork pouring in the excavated section behind the tunnel face, and grouting reinforcement is carried out on the unexcavated section in front of the tunnel face behind the plugging wall, and then the plugging wall is gradually demolished. However, the on-site pouring of the plugging wall not only has a long construction period but also is relatively slow in later demolition, seriously restricting the tunnel construction progress. Summary of the Invention

[0003] In view of the disadvantages of the long construction period and low efficiency of on-site pouring and disassembly of the advanced grouting plugging wall in the existing tunnel construction process, the present invention proposes a prefabricated advanced grouting plugging wall for tunnels to effectively improve the construction efficiency of the plugging wall and ensure the tunnel construction progress.

[0004] The technical solution adopted by the present invention is: a prefabricated advanced grouting plugging wall for tunnels, characterized in that: the overall structure of the plugging wall is an arch shape, the distance between the center of the plugging wall and the tunnel face is m, the distances between the two wings and the tunnel face are s, s>m, m≥0, the length L of the plugging wall is determined according to its radius R and the tunnel diameter, and the thickness is n; the height of the plugging wall is h, and h is the tunnel height; n and R are determined by technicians according to the on-site conditions of the tunnel; the plugging wall is distributed with prefabricated grouting holes, and the grouting holes are sealed with lids or plugs and opened during grouting. The arrangement pattern and the spacing a of the grouting holes on the plugging wall, as well as the included angle α with the tunnel axis direction, are determined by technicians according to the advanced grouting construction plan and the on-site conditions of the tunnel; the plugging wall is divided into i detachable layers from the tunnel floor to the tunnel crown, i≥1; among them, the first layer is in contact with the tunnel floor, with a height of b1, the second layer is above the first layer, with a height of b2, the third layer is above the second layer, with a height of b3, and so on. The i-th layer is above the (i - 1)-th layer, with a height of bi; i and the height bi of each layer are determined by technicians according to the on-site conditions of the tunnel, b1, b2, b3... bi may be the same or different, and b1 + b2 + b3... + bi is the height h of the plugging wall; each i-th layer of the plugging wall can be divided into j detachable assembly plates, namely i-①, i-②, i-③... i-j, j≥1; the front view of each assembly plate is a rectangle, with a thickness of the thickness n of the plugging wall, a height of bi, and a width of d i-j ; d i-1, d i-2 , d i-3 …d i-j Same or different, d i-1 +d i-2 +d i-3 …+d i-j The length L of the grouting stop wall; j and the width d of each assembly plate i-j To be determined by technicians according to the site conditions of the tunnel

[0005] Preferably, when the number j of assembly plates in each i - layer is odd, the top view of the (j + 1) / 2 - th assembly plate is wedge - shaped, that is, the included angle γ between the contact surfaces of the (j + 1) / 2 - th assembly plate and its adjacent assembly plates with the tunnel driving direction is an acute angle; when the number j of assembly plates in each i - layer is even, the included angles γ between the contact surfaces of the j / 2 - th and the j / 2 - 1 - th, the j / 2 + 1 - th and the j / 2 + 2 - th assembly plates with the tunnel driving direction are acute angles; γ is determined by technicians according to the site conditions of the tunnel. The contact surfaces between the remaining assembly plates are all parallel to the tunnel driving direction

[0006] Preferably, each assembly plate of the assembled grouting stop wall is a precast reinforced concrete structure or a metal structure with a certain strength; when it is a metal structure, to reduce the weight of the assembly plate and the grouting stop wall, the assembly plate can be a hollow structure. Each assembly plate surface has a position identifier of the assembly plate in the assembled grouting stop wall to facilitate installation

[0007] Preferably, on one side where each assembly plate of the grouting stop wall contacts its adjacent assembly plate, or on one side contacting the tunnel floor, a layer of water - stop rubber with a thickness of e is provided to prevent the grouting slurry from leaking into the tunnel during the grouting process; the size of e is determined by technicians according to the maximum grouting pressure

[0008] Preferably, on one side where the assembly plate contacts its adjacent assembly plate, an internal bolt tube or bolt hole is provided, and the bolt hole is located on the side of the assembly plate away from the tunnel face. During the installation of adjacent assembly plates, the bolt L1 is inserted into the internal bolt tube from the bolt hole outside the assembly plate and enters the internal bolt tube of the adjacent assembly plate, so that the assembly plate is connected and fixed to its adjacent assembly plate. The length of the bolt L1 and the insertion angle β into the assembly plate are determined by technicians according to the structure of the assembled grouting stop wall and the assembly plate

[0009] Preferably, a layer of expandable rubber with a thickness of c is provided on the side of the i-①th and i-jth assembly plates of the prefabricated grout stop wall close to the tunnel wall in contact with the tunnel wall. The side of the expandable rubber away from the tunnel wall is an elastic plate that bulges towards the tunnel wall. The rubber and the elastic plate are fixedly connected to the assembly plate on the side of the assembly plate close to the tunnel face, and are connected to a movable plate on the side of the assembly plate away from the tunnel face. The movable plate is connected to the assembly plate by a rotating shaft, so that the movable plate can rotate towards the tunneling direction of the tunnel along the rotating shaft. A bolt L2 is provided on the movable plate. The bolt L2 is fixed to the assembly plate on the side close to the tunnel face, passes through the movable plate and protrudes on the side away from the tunnel face. Tightening the bolt can make the movable plate rotate towards the tunneling direction of the tunnel along the rotating shaft, so that the elastic plate and the expandable rubber connected to the movable plate expand and press against the tunnel wall, and the length of L2 is greater than n.

[0010] Preferably, during the installation of each assembly plate of the prefabricated grout stop wall, a release agent needs to be applied to the side of the assembly plate close to the tunnel face and the expandable rubber, or other alternative release methods can be selected to ensure effective separation between the side of the assembly plate close to the tunnel face and the grouting material.

[0011] A method for using a prefabricated advanced grouting grout stop wall for a tunnel as described above includes the following steps:

[0012] S1. Determine the radius R, length L, thickness n of the grout stop wall, and the spacing and arrangement of the advanced grouting holes in the grout stop wall according to the tunnel construction conditions and the advanced grouting construction plan.

[0013] S2. According to the parameters of the grout stop wall determined in S1, manufacture each assembly plate of the prefabricated advanced grouting grout stop wall for the tunnel, and mark the positions on each assembly plate to facilitate installation;

[0014] S3. Install the 1-①th to 1-jth assembly plates at the bottom layer in contact with the tunnel floor of the prefabricated advanced grouting grout stop wall for the tunnel in the tunnel in sequence, and connect two adjacent assembly plates with bolts, and tighten the bolt L1 to fix the two adjacent assembly plates; if j is 1, this step is omitted.

[0015] S4. Rotate the bolt L2 to make the movable plate on the side of the 1-①th and 1-jth assembly plates in contact with the tunnel wall rotate towards the advancing direction of the tunnel and squeeze the elastic plate and the expandable rubber, so that the expandable rubber expands and is in close contact with the tunnel wall, and further clamp the first layer of the prefabricated advanced grouting grout stop wall against the tunnel walls on both sides; and apply a release agent to the side of the assembly plate close to the tunnel face;

[0016] S5. Install the 2-① to 2-jth assembled plates of the second layer of the prefabricated advanced grouting plugging wall for tunnel in sequence, and connect the bolts between the first layer and the second layer of assembled plates to fix the second layer of assembled plates to the first layer; Rotate the bolt L2 on the 2-① and 2-jth assembled plates to make the movable plate on the side of the assembled plate in contact with the tunnel wall rotate towards the advancing direction of the tunnel and squeeze the expandable rubber, so that the expandable rubber expands and is in close contact with the tunnel wall, thereby clamping the second layer of the prefabricated advanced grouting plugging wall for tunnel to the tunnel walls on both sides; And apply a release agent on the side of the assembled plate close to the heading face;

[0017] S6. Repeat S4 and S5, and finally complete the installation of the prefabricated advanced grouting plugging wall for tunnel;

[0018] S7. Open the prefabricated grouting holes on the prefabricated advanced grouting plugging wall for tunnel and conduct grouting; After the grouting is completed, close the grouting holes and wait for the grouting liquid to solidify;

[0019] S8. Rotate the bolt L2 on the i-① and i-jth assembled plates of the uppermost i-th layer to make the movable plate on the side of the i-th layer of assembled plate in contact with the tunnel wall rotate in the direction opposite to the advancing direction of the tunnel, so that the elastic plate and the expandable rubber contract, and the i-th layer of assembled plate is separated from the tunnel wall;

[0020] S9. Remove the bolt L1 between two adjacent assembled plates of the i-th layer and the bolt between it and the (i - 1)-th layer of assembled plates in sequence, and remove each assembled plate of the i-th layer;

[0021] S10. Repeat S8 and S9, and finally complete the disassembly of the prefabricated advanced grouting plugging wall for tunnel;

[0022] S11. Repair each assembled plate of the prefabricated advanced grouting plugging wall for tunnel and use it for the next advanced grouting.

[0023] The beneficial effects obtained by the present invention are as follows:

[0024] 1. Each assembled plate in the prefabricated advanced grouting plugging wall for tunnel provided by the present invention is a prefabricated reinforced concrete structure or a metal structure with a certain strength, which can be quickly installed before tunnel grouting and is convenient to disassemble after grouting, effectively improving the construction efficiency of the plugging wall during the advanced grouting process of the tunnel and ensuring the tunnel construction progress;

[0025] 2. After being disassembled, the prefabricated advanced grouting plugging wall for tunnel provided by the present invention can be used in the next advanced grouting construction after simple repair or replacement of the waterstop rubber, and can be reused multiple times, effectively reducing the tunnel construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a top view schematic diagram of the plugging wall of the present invention in the tunnel;

[0027] Figure 2 Front view schematic diagram of the grout - stopping wall of the present invention in the tunnel

[0028] Figure 3 Structural schematic diagram of the assembly plate at the center position of the i - th layer of the grout - stopping wall of the present invention

[0029] Figure 4 Structural schematic diagram of the assembly plate in contact with the tunnel wall in the grout - stopping wall of the present invention

[0030] Figure 5 Structural schematic diagram of the assembly plate not in contact with the tunnel wall in the grout - stopping wall of the present invention

[0031] Figure 6 Schematic diagram of the arrangement of bolt pipes (or bolt holes) on the assembly plate

[0032] Figure 7 Schematic diagram of the installation of bolt L1 between two adjacent assembly plates in the grout - stopping wall of the present invention

[0033] Where: 1, tunnel face; 2, grout - stopping wall; 21, grouting hole; 3, tunnel wall; 31, tunnel floor; 4, water - stop rubber; 5, bolt pipe (or bolt hole); 6, expandable rubber; 61, elastic plate; 7, rotating shaft; 8, movable plate; 9, bolt L2; 10, assembly position mark; 11, bolt L1; m is the distance between the center of the grout - stopping wall and the tunnel face; s is the distance between the two wings of the grout - stopping wall and the tunnel face; n is the thickness of the grout - stopping wall; R is the radius of the grout - stopping wall; a is the row - spacing of the grouting holes; α is the angle between the grouting hole and the tunnel axis; bi is the height of the assembly plate; di - j is the width of the assembly plate; h is the height of the tunnel; e is the thickness of the water - stop rubber on the assembly plate; c is the thickness of the expandable rubber in the assembly plate in contact with the tunnel wall; L1 is the length of the bolt connecting two adjacent assembly plates; β is the angle at which the bolt connecting two adjacent assembly plates is inserted into the assembly plate; L2 is the length of the bolt connecting the movable plate in the assembly plate in contact with the tunnel wall Detailed implementation manners

[0034] Next, the technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention

[0035] As Figures 1-7 shown, the present invention provides an assembled advanced grouting grout - stopping wall for a tunnel. The assembled grout - stopping wall 2 is an arch - shaped structure overall ( Figure 1) The distance between the center of the grout stopping wall 2 and the heading face 1 is m, and the distances from the two wings to the heading face 1 are s. s is greater than m, and m is greater than or equal to 0. The length L of the grout stopping wall 2 is determined according to its radius R and the tunnel diameter, and the thickness is n; the height h of the grout stopping wall 2 is the tunnel height; n and R are determined by the technical personnel according to the on-site conditions of the tunnel.

[0036] The prefabricated grouting holes 21 are distributed on the assembled grout stopping wall 2 ( Figure 1 and Figure 2 ). The grouting holes 21 are sealed with lids or plugs and opened during grouting; the arrangement pattern, the spacing a between rows and columns, and the included angle α with the tunnel axis direction of the grouting holes 21 on the grout stopping wall 2 are determined by the technical personnel according to the advanced grouting construction plan and the on-site conditions of the tunnel.

[0037] The assembled grout stopping wall 2 is divided into i detachable layers from the tunnel floor 31 to the tunnel crown arch ( Figure 2 ), where i is greater than or equal to 1. Among them, the first layer is in contact with the tunnel floor 31, with a height of b1, the second layer is above the first layer, with a height of b2, the third layer is above the second layer, with a height of b3, and so on. The i-th layer is above the (i - 1)-th layer, with a height of bi; i and the height bi of each layer are determined by the technical personnel according to the on-site conditions of the tunnel. b1, b2, b3... bi can be the same or different, and b1 + b2 + b3... + bi is the height h of the grout stopping wall.

[0038] Each i-th layer of the assembled grout stopping wall 2 can be divided into j detachable assembly plates ( Figure 2 ), namely i-①, i-②, i-③... i-j, where j is greater than or equal to 1; the front view of each assembly plate is a rectangle, with a thickness of the thickness n of the grout stopping wall, a height of bi, and a width of d i-j ; d i-1 、d i-2 、d i-3 …d i-j can be the same or different, and d i-1 +d i-2 +d i-3 …+d i-j is the length L of the grout stopping wall; j and the width d of each assembly plate i-j are determined by the technical personnel according to the on-site conditions of the tunnel.

[0039] When the number j of the assembly plates of each i-th layer of the assembled grout stopping wall 2 is an odd number ( Figure 3), the top view of the ((j + 1) / 2)-th assembly plate is wedge-shaped, that is, the included angle γ between the contact surfaces of the ((j + 1) / 2)-th assembly plate and the two side assembly plates and the tunnel driving direction is an acute angle; when the number j of assembly plates in each i-th layer is even, the included angles γ between the contact surfaces of the j / 2-th and (j / 2 - 1)-th, and the (j / 2 + 1)-th and (j / 2 + 2)-th assembly plates and the tunnel driving direction are acute angles; γ is determined by the technical personnel according to the on-site conditions of the tunnel. The contact surfaces between the remaining assembly plates are all parallel to the tunnel driving direction.

[0040] Each assembly plate of the prefabricated grouting stop wall 2 is a precast reinforced concrete structure or a metal structure with a certain strength; when it is a metal structure, in order to reduce the weight of the assembly plate and the grouting stop wall, the assembly plate can be a hollow structure. There is a position identification of the assembly plate in the prefabricated grouting stop wall on the surface of each assembly plate to facilitate installation.

[0041] On one side where each assembly plate of the prefabricated grouting stop wall 2 contacts its adjacent assembly plate, or on one side contacting the tunnel floor, a layer of water-stop rubber 4 with a thickness of e is provided ( Figure 4 and Figure 6 ), to prevent the grouting slurry from leaking into the tunnel during the grouting process; the size of e is determined by the technical personnel according to the maximum grouting pressure.

[0042] An internal bolt pipe or bolt hole 5 is provided on one side where the assembly plate of the prefabricated grouting stop wall 2 contacts its adjacent assembly plate, and the bolt hole 5 is located on the side of the assembly plate away from the tunnel face 1 ( Figure 6 and Figure 7 ). During the installation of adjacent assembly plates, the bolt L1 is inserted into the internal bolt pipe from the bolt hole on the outside of the assembly plate and enters the internal bolt pipe of the adjacent assembly plate, so that the assembly plate is connected and fixed to its adjacent assembly plate ( Figure 7 ), and the length of the bolt L1 and the insertion angle β into the assembly plate are determined by the technical personnel according to the structure of the prefabricated grouting stop wall and the assembly plate.

[0043] On one side where the (i - ①)-th and (i - j)-th assembly plates of the prefabricated grouting stop wall 2 close to the tunnel wall 3 contact the tunnel wall 3, a layer of expandable rubber 6 with a thickness of c is provided ( Figure 5) On the side of the expandable rubber 6 away from the hole wall 1 is an elastic plate 61, which bulges towards the hole wall 1. The expandable rubber 6 and the elastic plate 61 are fixedly connected to the assembly plate on the side close to the tunnel face 1 of the assembly plate, and are connected to a movable plate 8 on the side of the assembly plate away from the tunnel face 1. The movable plate 8 is connected to the assembly plate through a rotating shaft 1, so that the movable plate 8 can rotate towards the tunnel excavation direction along the rotating shaft 7. Bolts L2 are arranged on the movable plate. The side of the bolts L2 close to the tunnel face 1 is fixed on the assembly plate, and the side away from the tunnel face 1 passes through the movable plate 8 and protrudes. Tightening the bolts 9 can make the movable plate 8 rotate towards the tunnel excavation direction along the rotating shaft 7, so that the elastic plate 61 and the expandable rubber 6 connected to the movable plate 8 expand and press tightly against the hole wall 31, and the length of L2 is greater than n.

[0044] During the installation of each assembly plate of the pre-grouting plugging wall 2, a release agent needs to be applied to the side of the assembly plate close to the tunnel face 1 and the expandable rubber 6, or other alternative release methods can be selected to ensure the effective separation of the side of the assembly plate close to the tunnel face 1 from the grouting material.

[0045] The usage method of the above-mentioned pre-grouting plugging wall for a tunnel includes the following steps:

[0046] (1) Technicians determine the radius R, length L, thickness n of the plugging wall, as well as the spacing a and arrangement pattern of the pre-grouting holes in the plugging wall according to the tunnel construction conditions and the pre-grouting construction plan;

[0047] (2) According to the parameters of the plugging wall determined by the technicians, each assembly plate of the pre-grouting plugging wall for a tunnel is manufactured, and position markings are made on each assembly plate to facilitate installation;

[0048] (3) Install the 1-① to 1-jth assembly plates at the bottom layer in contact with the tunnel floor of the pre-grouting plugging wall for a tunnel in the tunnel in sequence, and connect two adjacent assembly plates with bolts, and tighten the bolts L1 to fix the two adjacent assembly plates; if j is 1, this step is omitted;

[0049] (4) Rotate the bolts L2 to make the movable plates on the sides of the 1-① and 1-jth assembly plates in contact with the tunnel wall rotate towards the tunnel advancing direction and squeeze the elastic plate and the expandable rubber to expand, so that the expandable rubber expands and is in close contact with the hole wall, thereby clamping the first layer of the pre-grouting plugging wall for a tunnel tightly against the tunnel side walls; and apply a release agent to the side of the assembly plate close to the face.

[0050] (5) Install the 2-① to 2-jth assembly plates of the second layer of the prefabricated tunnel advanced grouting plugging wall in sequence, and connect the bolts between the first layer and the second layer of assembly plates to fix the second layer of assembly plates to the first layer; Rotate the bolt L2 on the 2-① and 2-jth assembly plates to rotate the movable plate on the side of the assembly plate in contact with the tunnel wall towards the advancing direction of the tunnel and squeeze the expandable rubber, so that the expandable rubber expands and is in close contact with the tunnel wall, and then the second layer of the prefabricated tunnel advanced grouting plugging wall is clamped to the tunnel walls on both sides; And apply a release agent on the side of the assembly plate close to the heading face;

[0051] (6) Repeat steps (4) and (5), and finally complete the installation of the prefabricated tunnel advanced grouting plugging wall;

[0052] (7) Open the grouting holes prefabricated on the prefabricated tunnel advanced grouting plugging wall for grouting; After the grouting is completed, close the grouting holes and wait for the grouting liquid to solidify;

[0053] (8) Rotate the bolt L2 on the i-① and i-jth assembly plates of the uppermost i-th layer to rotate the movable plate on the side of the i-th layer of assembly plate in contact with the tunnel wall in the direction opposite to the advancing direction of the tunnel, so that the elastic plate and the expandable rubber contract, and the i-th layer of assembly plate is separated from the tunnel wall;

[0054] (9) Remove the bolt L1 between the adjacent two assembly plates of the i-th layer and the bolt between it and the (i - 1)-th layer of assembly plate in sequence, and remove each assembly plate of the i-th layer;

[0055] (10) Repeat steps (8) and (9), and finally complete the disassembly of the prefabricated tunnel advanced grouting plugging wall;

[0056] (11) Inspect each assembly plate of the prefabricated tunnel advanced grouting plugging wall and use it for the next advanced grouting.

[0057] Here, it should be noted that the description of the above technical solution is exemplary, and this specification can be embodied in different forms and should not be construed as limited to the technical solutions described herein. On the contrary, providing these descriptions will make the disclosure of the present invention thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solution of the present invention is only limited by the scope of the claims.

[0058] Finally, it should be pointed out that the above embodiments are only relatively representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and there can be many variations. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention should be considered to fall within the protection scope of the present invention.

Claims

1. An assembled tunnel advance grouting stop wall, characterized in that: The grouting wall is an arch structure as a whole, with a distance of m between the center of the grouting wall and the tunnel face, and a distance of s between the two wings and the tunnel face, s is greater than m, and m is greater than or equal to 0; the grouting wall is distributed with prefabricated grouting holes, which are sealed with covers or plugs and opened during grouting; the grouting wall is divided into i detachable layers from the tunnel bottom plate to the tunnel top arch, where i is greater than or equal to 1; wherein the first layer is in contact with the tunnel bottom plate, with a height of b1, the second layer is above the first layer, with a height of b2, the third layer is above the second layer, with a height of b3, and so on, the i-th layer is above the i-1 layer, with a height of bi; b1, b2, b3…bi are the same or different, b1+b2+b3…+bi is the height h of the grouting wall; each i layer of the grouting wall can be divided into j detachable assembly plates, i-①, i-②, i-③…ij, respectively, with j greater than or equal to 1; the front view of each assembly plate is a rectangle, with a thickness of n being the thickness of the grouting wall, a height of bi, and a width of d i-j ;d i-1 d i-2 d i-3 …d i-j Same or different, i-1 +d i-2 +d i-3 …+d i-j The length L of the grouting wall.

2. The prefabricated tunnel advance grouting stop wall according to claim 1 is characterized in that: When the number j of assembly plates per i-layer is an odd number, the top view of the (j+1) / 2-th assembly plate is wedge-shaped, that is, the angle γ between the contact surface of the (j+1) / 2-th assembly plate and the assembly plates on both sides thereof and the tunnel excavation direction is an acute angle; when the number j of assembly plates per i-layer is an even number, the angle γ between the contact surface of the j / 2-th assembly plate and the j / 2-1-th assembly plate, and the contact surface of the j / 2+1-th assembly plate and the j / 2+2-th assembly plate and the tunnel excavation direction is an acute angle.

3. The prefabricated tunnel advance grouting stop wall according to claim 1 is characterized in that: Each assembly plate of the slurry stop wall is a prefabricated reinforced concrete structure or metal structure, and a position mark is provided on the surface of each assembly plate.

4. The prefabricated tunnel advance grouting stop wall according to claim 3 is characterized in that: Each assembly panel of the stop wall is a hollow metal structure.

5. The prefabricated tunnel advance grouting stop wall according to claim 1 is characterized in that: A layer of water-stop rubber with a thickness of e is provided on the side of each assembly plate in contact with its adjacent assembly plate, or on the side in contact with the tunnel bottom plate.

6. The prefabricated tunnel advance grouting stop wall according to claim 1 is characterized in that: An internal bolt tube or bolt hole is provided on the side of the assembly plate in contact with its adjacent assembly plate, and the bolt hole is located on the side of the assembly plate away from the tunnel face; during the installation of the adjacent assembly plates, the bolts are inserted into the internal bolt tube from the bolt holes on the outside of the assembly plate, and enter the internal bolt tube of the adjacent assembly plate, so that the assembly plate is connected and fixed to the adjacent assembly plate.

7. The prefabricated tunnel advance grouting stop wall according to claim 1 is characterized in that: A layer of expandable rubber with a thickness of c is arranged on the side where the i-①th and ijth assembly plates of the slurry-stopping wall contact the cave wall.

8. The prefabricated tunnel advance grouting stop wall according to claim 7 is characterized in that: An elastic plate is provided on the side of the expandable rubber away from the tunnel wall, and the elastic plate protrudes toward the tunnel wall; the expandable rubber and the elastic plate are fixedly connected to the mounting plate on the side of the mounting plate close to the tunnel face, and are connected to the movable plate on the side of the mounting plate away from the tunnel face; the movable plate is connected to the mounting plate through a rotating shaft, so that the movable plate can rotate along the rotating shaft in the tunnel excavation direction; bolts are provided on the movable plate, and the bolts are fixed to the mounting plate on the side close to the tunnel face, and pass through the movable plate on the side away from the tunnel face and are exposed, and tightening the bolts can make the movable plate rotate along the rotating shaft in the tunnel excavation direction, so that the elastic plate and the expandable rubber connected to the movable plate expand and press the tunnel wall.

9. The prefabricated tunnel advance grouting stop wall according to claim 7 is characterized in that: Apply release agent on the side of the assembly plate close to the tunnel face and on the expandable rubber.

10. A method for using the prefabricated tunnel advance grouting grouting stop wall according to any one of claims 1 to 9, comprising the following steps: S1. Determine the radius R, length L, thickness n of the stop wall, and the spacing a and arrangement of the advance grouting holes in the stop wall according to the tunnel construction conditions and the advance grouting construction plan. S2. According to the parameters of the stop wall determined in S1, each assembly plate of the prefabricated tunnel advance grouting stop wall is manufactured, and the position is marked on each assembly plate to facilitate installation; S3. Install the 1-① to 1-j assembly plates of the bottom layer where the prefabricated tunnel advance grouting stop wall contacts the tunnel bottom plate in sequence in the tunnel, connect two adjacent assembly plates with bolts, tighten the bolts L1 to fix the two adjacent assembly plates; if j is 1, omit this step. S4, turning the bolt L2 to make the movable plates on the side of the 1-① and 1-j assembly plates in contact with the tunnel wall rotate in the tunnel forward direction and squeeze the elastic plate and the expandable rubber, so that the expandable rubber expands and comes into close contact with the tunnel wall, thereby making the first layer of the prefabricated tunnel advance grouting stop wall clamp the tunnel walls on both sides; and applying a release agent on the side of the assembly plate close to the tunnel face; S5. Install the 2-① to 2-j assembly plates of the second layer of the prefabricated tunnel advance grouting stop wall in sequence, and connect the bolts between the 1st and 2nd assembly plates to fix the 2nd assembly plate to the 1st assembly plate; rotate the bolts L2 on the 2-① and 2-j assembly plates to rotate the movable plate on the side of the assembly plate in contact with the tunnel wall in the forward direction of the tunnel and squeeze the expandable rubber, so that the expandable rubber expands and is in close contact with the tunnel wall, thereby making the second layer of the prefabricated tunnel advance grouting stop wall clamp the tunnel walls on both sides; and apply a release agent on the side of the assembly plate close to the tunnel face; S6, repeat S4 and S5, and finally complete the installation of the prefabricated tunnel advance grouting stop wall; S7, opening the prefabricated grouting holes of the prefabricated tunnel advance grouting stop wall to perform grouting; after the grouting is completed, closing the grouting holes and waiting for the grouting liquid to solidify; S8, rotating the bolts L2 on the i-① and ij-th assembly plates of the i-th layer at the top, so that the movable plate on the side of the i-th assembly plate in contact with the tunnel wall rotates in the direction opposite to the tunnel advance direction, so that the elastic plate and the expandable rubber contract, so that the i-th assembly plate is separated from the tunnel wall; S9, remove the bolts L1 between two adjacent assembly plates of the i-th layer and the bolts between the assembly plates of the i-th layer and the i-1-th layer in sequence, and remove each assembly plate of the i-th layer; S10, repeat S8 and S9, and finally complete the dismantling of the prefabricated tunnel advance grouting stop wall; S11. Inspect and repair each assembly plate of the prefabricated tunnel advance grouting stop wall and use it for the next advance grouting.

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