A method for constructing a high-pressure water-rich fault zone tunnel advance construction grout wall

Abstract

The application provides a construction method of a high-pressure water-rich fault zone tunnel advanced construction grout stopping wall, comprising the following steps: calculating the thickness of the grout stopping wall; demarcating a free surface, and forming a pouring space between the free surface and a roadway cross section; opening a first drill hole group and a second drill hole group on the roadway cross section; stacking a first sandbag pile in the pouring space, inserting a drainage steel pipe into the drill hole with the first sandbag pile as a support; forming a filling space between the first sandbag pile and the roadway cross section, and filling a gravel layer into the filling space; erecting a first steel mesh and a second steel mesh in the pouring space to divide the pouring space into a first pouring area, a second pouring area and a third pouring area; arranging an auxiliary pipe group in the pouring space; and pouring concrete into the first pouring area, the second pouring area and the third pouring area in sequence to form the grout stopping wall. Preferably, the thickness of the grout stopping wall is calculated to improve the compression resistance of the grout stopping wall; and the concrete is poured in the pouring space to improve the overall compression strength of the grout stopping wall and ensure the construction safety.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to a method for constructing a grout-stopping wall for advanced construction in a high-pressure, water-rich fault zone tunnel. Background Technology

[0002] With the continuous development of transportation engineering, many railway and highway tunnels need to traverse various complex geological conditions during construction. For tunnel construction in areas with numerous high-pressure, water-rich fault zones, the stability support of the working face requires extremely high stability standards.

[0003] Full-face pre-curtain grouting is a common technique used in tunnel construction under complex geological conditions, particularly when crossing high-pressure, water-rich fault zones. Due to the high grouting pressure and large water inflow at the working face, a grout stop wall needs to be constructed before grouting. This is to prevent backflow of high-pressure grout during grouting and to prevent water and mud inrush disasters during construction.

[0004] In the construction of existing grout-stopping walls, bagged cement is typically piled up at the bottom of the working face of the roadway, and concrete is filled into the space enclosed by the bagged cement to block the water inflow at the working face of the roadway. However, the grout-stopping wall formed by this construction method can only withstand a small amount of grouting pressure and water inflow pressure, making it difficult to ensure construction safety. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for constructing a grout-stopping wall in advance construction of tunnels in high-pressure, water-rich fault zones. This method addresses the technical problem that existing technologies, which involve piling up bagged cement at the bottom of the tunnel face and filling the space enclosed by the bagged cement with concrete to form a grout-stopping wall, have relatively low grouting and water inflow pressure resistance, making it difficult to ensure construction safety.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] A method for constructing a grout-stopping wall for advanced construction of tunnels in high-pressure, water-rich fault zones includes the following steps:

[0008] The thickness of the grout-stopping wall is calculated based on the grouting pressure, the dimensions of the tunnel cross-section, and the axial compressive strength of the concrete.

[0009] A free surface is defined with the tunnel cross-section as the starting point and the thickness of the grout-stopping wall as the distance, and a pouring space is formed between the free surface and the tunnel cross-section;

[0010] A first borehole group and a second borehole group are formed from top to bottom on the cross section of the roadway. The first borehole group forms a first height with the bottom of the cross section of the roadway, and the second borehole group forms a second height with the bottom of the roadway. Both the first borehole group and the second borehole group include a number of evenly spaced boreholes.

[0011] A first sandbag pile is built in the pouring space. A third height is formed between the top of the first sandbag pile and the bottom of the tunnel section. With the first sandbag pile as support, a drainage steel pipe is inserted into the borehole. One end of the drainage steel pipe is inserted into the borehole, and the other end of the drainage steel pipe passes through the free surface and protrudes out of the pouring space.

[0012] A filling space is formed between the first sandbag pile and the tunnel cross-section. A layer of crushed stone is filled into the filling space, and a second sandbag pile is laid on top of the crushed stone layer.

[0013] A first steel mesh and a second steel mesh are erected within the pouring space. The first steel mesh is located on top of the second sandbag pile, and the second steel mesh abuts against the side of the first sandbag pile facing away from the gravel layer, so as to divide the pouring space from the tunnel section toward the free face into a first pouring area, a second pouring area and a third pouring area.

[0014] An auxiliary pipe assembly is installed within the pouring space, with one end of the auxiliary pipe assembly abutting the roadway cross section and the other end of the auxiliary pipe assembly abutting the free surface.

[0015] Concrete is poured sequentially in the first pouring area, the second pouring area, and the third pouring area to form a grout-stopping wall within the pouring space.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The thickness of the grout-stopping wall is calculated based on the grouting pressure, the axial compressive strength of the concrete, and the dimensions of the roadway cross-section. When designing the thickness of the grout-stopping wall, factors such as the grouting pressure are preferably considered, thus improving the compressive strength of the grout-stopping wall. After determining the thickness of the grout-stopping wall, by setting the crushed stone layer within the filling space, water from the strata can be induced into the crushed stone layer, and the water can be discharged through the drainage steel pipe passing through the crushed stone layer, alleviating the problem of inconvenient construction due to large water inflow in water-rich working faces, and simultaneously relieving water pressure. Pouring the concrete within the pouring space further improves the overall compressive strength of the grout-stopping wall, ensuring construction safety. By setting the auxiliary pipe within the pouring space, it is convenient to guide the drilling direction of the grouting holes, and the hole wall of the grouting hole is directly made of the concrete.

[0017] Furthermore, the formula for calculating the thickness of the grout-stopping wall is as follows:

[0018]

[0019] Where B represents the thickness of the grout-stopping wall, k represents the safety factor, p represents the grouting pressure, S represents the area of ​​the tunnel cross-section, b represents the width of the tunnel cross-section, h represents the height of the tunnel cross-section, and σ c It represents the axial compressive strength of concrete.

[0020] Furthermore, the first height is 38cm to 42cm, the second height is 18cm to 22cm, the diameter of the drill hole is 100mm to 120mm, and the depth of the drill hole is 1m to 2m.

[0021] Furthermore, the step of piling a first sandbag pile within the pouring space, forming a third height between the top of the first sandbag pile and the bottom of the tunnel section, and inserting a drainage steel pipe into the borehole using the first sandbag pile as support, specifically involves:

[0022] A first sandbag pile is constructed within the pouring space along the width of the tunnel cross-section.

[0023] When the height of the first sandbag pile reaches the second height, a drainage steel pipe is inserted into the borehole in the second borehole group;

[0024] When the height of the first sandbag pile reaches the first height, the drainage steel pipe is inserted into the hole in the first drilling group;

[0025] Continue piling up the first sandbag pile until a third height is formed between the top of the first sandbag pile and the bottom of the tunnel section.

[0026] Furthermore, the third height is 60cm to 100cm, and several drainage holes are opened on the side wall of the end of the drainage steel pipe near the cross-section of the roadway. The several drainage holes are evenly distributed around the drainage steel pipe. The diameter of the drainage steel pipe is 100mm to 120mm, and the diameter of the drainage holes is 5mm to 12mm.

[0027] Furthermore, after the steps of forming a filling space between the first sandbag pile and the tunnel cross-section, filling the filling space with a layer of crushed stone, and laying a second sandbag pile on top of the crushed stone layer, the method further includes:

[0028] A layer of fine sand is laid on the second sandbag pile.

[0029] Furthermore, the auxiliary pipe group includes a central auxiliary pipe, a first pipe group, and a second pipe group arranged sequentially from the inside out. The first pipe group includes a plurality of first inclined pipes arranged around the central auxiliary pipe, and the second pipe group includes a plurality of second inclined pipes arranged around the central auxiliary pipe. The central auxiliary pipe is parallel to the axis of the roadway cross section. The first inclined pipe and the central auxiliary pipe form a first deflection angle, and the second inclined pipe and the central auxiliary pipe form a second deflection angle.

[0030] Furthermore, the first deflection angle is 5° to 10°, and the second deflection angle is 10° to 20°.

[0031] Furthermore, the concrete is formed by mixing water, cement, NF-F composite admixture, BTS-1001 CSA high-performance expansive agent, polyvinyl alcohol fiber, imitation steel fiber, sand, and gravel. The mixing ratio of the water, cement, NF-F composite admixture, BTS-1001 CSA high-performance expansive agent, polyvinyl alcohol fiber, imitation steel fiber, sand, and gravel is 166.1:410.0:130.0:32.8:1.1:5.0:616.0:1095.1.

[0032] Furthermore, after the step of defining the free surface with the tunnel cross-section as the starting point and the thickness of the grout-stopping wall as the distance, and forming a pouring space between the free surface and the tunnel cross-section, the method further includes:

[0033] Several anchor bolts are inserted along the outer edge of the tunnel cross section, and a first interval is formed between adjacent anchor bolts. Attached Figure Description

[0034] Figure 1 This is a flowchart illustrating the construction method of the grout-stopping wall for the advanced construction of a tunnel in a high-pressure water-rich fault zone, as described in this invention.

[0035] Figure 2 This is a schematic diagram of the structure of the anchor bolt inserted into the tunnel section in the construction method of the grout-stopping wall for the advanced construction of tunnels in high-pressure water-rich fault zones in an embodiment of the present invention.

[0036] Figure 3 This is a schematic cross-sectional view of the grout-stopping wall after pouring in the construction method of the grout-stopping wall for the advanced construction of tunnels in high-pressure water-rich fault zones in an embodiment of the present invention.

[0037] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0038] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0039] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] Please see Figure 1 The method for constructing the grout-stopping wall for advanced construction of tunnels in high-pressure water-rich fault zones according to embodiments of the present invention includes the following steps:

[0042] S10: Calculate the thickness of the grout-stopping wall based on the grouting pressure, the dimensions of the tunnel cross-section, and the axial compressive strength of the concrete;

[0043] The formula for calculating the thickness of the grout-stopping wall is as follows:

[0044]

[0045] Where B represents the thickness of the grout-stopping wall, k represents the safety factor, p represents the grouting pressure, S represents the area of ​​the tunnel cross-section, b represents the width of the tunnel cross-section, h represents the height of the tunnel cross-section, and σ c It represents the axial compressive strength of concrete.

[0046] The thickness of the grout-stopping wall is calculated based on the grouting pressure, the axial compressive strength of the concrete, and the dimensions of the tunnel cross-section. When designing the thickness of the grout-stopping wall, factors such as the grouting pressure are preferably considered, thereby improving the compressive strength of the grout-stopping wall.

[0047] S20: A free surface is defined with the tunnel section as the starting point and the thickness of the grout-stopping wall as the distance, and a pouring space is formed between the free surface and the tunnel section;

[0048] Understandably, the free face 2 and the tunnel section 1 are parallel to each other, and the distance from the free face 2 to the tunnel section 1 is the thickness of the grout-stopping wall. The grout-stopping wall is formed by pouring concrete 11 within the pouring space.

[0049] Please see Figure 2 After step S20, the method further includes: inserting a plurality of anchor bolts along the outer edge of the roadway cross section, with a first interval between adjacent anchor bolts.

[0050] The anchor bolt 3 partially passes through the roadway section 1 and is inserted into the roadway, meaning the anchor bolt 3 is perpendicular to the roadway section 1. The first interval distance is 0.8m to 1.2m; in this embodiment, the first interval distance is 1m. The diameter of the anchor bolt 3 is 20mm to 25mm; in this embodiment, the diameter of the anchor bolt 3 is 22mm. The length of the anchor bolt 3 is 1.5m to 3.0m; in this embodiment, the length of the anchor bolt 3 is 2.5m. The length of the anchor bolt 3 can be adjusted according to the degree of fracture of the surrounding rock in the roadway. By inserting the anchor bolt 3, the roadway support can be made more stable under poor construction conditions, ensuring the safety of the grout stop wall construction and reducing the possibility of roof collapse and sidewall spalling during construction.

[0051] S30: A first borehole group and a second borehole group are opened from top to bottom on the cross section of the roadway. The first borehole group forms a first height with the bottom of the cross section of the roadway, and the second borehole group forms a second height with the bottom of the roadway. Both the first borehole group and the second borehole group include a number of evenly distributed boreholes.

[0052] Preferably, the first height is 38cm to 42cm, and the second height is 18cm to 22cm. In this embodiment, the first height is 40cm and the second height is 20cm. The diameter of the drill hole is 100mm to 120mm. In this embodiment, the diameter of the drill hole is 110mm. The depth of the drill hole is 1m to 2m. In this embodiment, the depth of the drill hole is 1.5m.

[0053] S40: A first sandbag pile is built in the pouring space, and a third height is formed between the top of the first sandbag pile and the bottom of the tunnel section. With the first sandbag pile as support, a drainage steel pipe is inserted into the borehole. One end of the drainage steel pipe is inserted into the borehole, and the other end of the drainage steel pipe passes through the free surface and protrudes out of the pouring space.

[0054] The first sandbag pile 4 is piled up at a preset distance from the tunnel section 1. The preset distance is 1.5m to 2.0m. In this embodiment, the preset distance is 1.8m.

[0055] Specifically, the step of piling a first sandbag pile within the pouring space, forming a third height between the top of the first sandbag pile and the bottom of the tunnel cross-section, and inserting a drainage steel pipe into the borehole using the first sandbag pile as support, is as follows:

[0056] A first sandbag pile is constructed within the pouring space along the width of the tunnel cross-section.

[0057] When the height of the first sandbag pile reaches the second height, a drainage steel pipe is inserted into the borehole in the second borehole group;

[0058] That is, when the first sandbag pile 4 is piled up to the second height, one end of the drainage steel pipe 5 is inserted into the hole in the second drilling group. The drainage steel pipe 5 is kept suspended by the support of the first sandbag pile 4. By continuing to pile up the first sandbag pile 4, the first sandbag pile 4 and the hole cooperate with each other to make the drainage steel pipe 5 inserted into the second drilling group achieve a stable structure.

[0059] When the height of the first sandbag pile reaches the first height, the drainage steel pipe is inserted into the hole in the first drilling group;

[0060] The insertion and fixing methods in this step are the same as in the previous step, so they will not be repeated here.

[0061] Continue piling up the first sandbag pile until a third height is formed between the top of the first sandbag pile and the bottom of the tunnel section.

[0062] The third height is 60cm to 100cm, and in this embodiment, the third height is 80cm.

[0063] S50: A filling space is formed between the first sandbag pile and the tunnel section, a layer of crushed stone is filled into the filling space, and a second sandbag pile is laid on top of the crushed stone layer;

[0064] The drainage steel pipe 5 has several drainage holes on its sidewall near one end of the roadway section 1. These drainage holes are evenly distributed around the drainage steel pipe 5. The diameter of the drainage steel pipe 5 is 100mm–120mm, and the diameter of the drainage holes is 5mm–12mm. In this embodiment, the diameter of the drainage steel pipe 5 is 110mm, and the diameter of the drainage holes is 8mm. Preferably, the drainage holes are located within the filling space. By setting the crushed stone layer 8 within the filling space, ground water can be induced into the crushed stone layer 8, and the water can be discharged through the drainage steel pipe 5 passing through the crushed stone layer 8. This alleviates the problem of inconvenient construction due to large water inflow in the water-rich working face and also relieves the water pressure. By setting the second sandbag pile, it can be prevented that concrete 11 will flow into the crushed stone layer 8 and block the drainage steel pipe 5 during subsequent concrete pouring.

[0065] Furthermore, a high-pressure ball valve 6 is screwed to one end of the drainage pipe away from the tunnel section 1. By excavating a water collection pit 7 corresponding to the position of the high-pressure ball valve 6 on the ground, the water in the stratum can be drained into the water collection pit 7. A water pump is installed in the water collection pit 7 to complete the pumping.

[0066] The crushed stone layer 8 is formed by the accumulation of several crushed stones, the particle size of which is 10mm to 50mm. In this embodiment, the particle size of the crushed stones is 30mm.

[0067] After step S50, the method further includes: laying a layer of fine sand on the second sandbag pile.

[0068] The fine sand layer is formed by the accumulation of fine sand, and its thickness is 50mm to 100mm. In this embodiment, the thickness of the fine sand layer is 80mm. By setting the fine sand layer, the gaps between the second sandbag piles can be filled to form a flat surface. At the same time, it can also block the gaps between the second sandbag piles, further preventing concrete 11 from entering the crushed stone layer 8.

[0069] S60: A first steel mesh and a second steel mesh are erected in the pouring space. The first steel mesh is located on top of the second sandbag pile, and the second steel mesh abuts against the side of the first sandbag pile facing away from the gravel layer, so as to divide the pouring space from the tunnel section to the free face into a first pouring area, a second pouring area and a third pouring area.

[0070] Both the first reinforcing mesh 91 and the second reinforcing mesh 92 are parallel to the tunnel section 1. Preferably, the distance between the first reinforcing mesh 91 and the tunnel section 1 is 0.75m to 1m. In this embodiment, the distance between the first reinforcing mesh 91 and the tunnel section 1 is 0.9m. By setting the first reinforcing mesh 91 and the second reinforcing mesh 92, the situation where concrete 11 spills due to excessive distance between them during the pouring process from the tunnel section 1 to the free face 2 can be avoided.

[0071] S70: An auxiliary pipe assembly is installed in the pouring space, one end of the auxiliary pipe assembly abutting the roadway cross section, and the other end of the auxiliary pipe assembly abutting the free surface;

[0072] The auxiliary pipe assembly 10 serves to guide the drilling direction of the grouting holes after the concrete 11 is poured and the grout-stopping wall is formed. The auxiliary pipe assembly 10 includes a central auxiliary pipe, a first pipe assembly, and a second pipe assembly arranged sequentially from the inside out. The first pipe assembly includes several first inclined pipes surrounding the central auxiliary pipe, and the second pipe assembly includes several second inclined pipes surrounding the central auxiliary pipe. The central auxiliary pipe is parallel to the axis of the roadway section 1. A first angle is formed between the first inclined pipe and the central auxiliary pipe, and a second angle is formed between the second inclined pipe and the central auxiliary pipe. The first angle is 5°–10°, and the second angle is 10°–20°. In this embodiment, the first angle is 8°, and the second angle is 12°. The lengths of the central auxiliary pipe, the first inclined pipe, and the second inclined pipe can be adjusted according to the thickness of the grout-stopping wall. It is understood that the central auxiliary pipe, the first inclined pipe, and the second inclined pipe are all made of PVC.

[0073] S80: Concrete is poured sequentially in the first pouring area, the second pouring area and the third pouring area to form a grout-stopping wall in the pouring space.

[0074] Preferably, a rectangular opening is provided on the second reinforcing mesh 92 so that construction workers can pass through the second reinforcing mesh 92 to carry out construction within the second pouring area when pouring concrete 11 into the first pouring area. Pouring the concrete 11 within the pouring space to form the grout-stopping wall can further improve the overall compressive strength of the grout-stopping wall and ensure construction safety.

[0075] Preferably, the concrete 11 is formed by mixing water, cement, NF-F composite admixture, BTS-1001 type CSA high-performance expansive agent, polyvinyl alcohol fiber, imitation steel fiber, sand, and gravel. The mixing ratio of the water, cement, NF-F composite admixture, BTS-1001 type CSA high-performance expansive agent, polyvinyl alcohol fiber, imitation steel fiber, sand, and gravel is 166.1:410.0:130.0:32.8:1.1:5.0:616.0:1095.1. The concrete 11 formed by mixing the components and proportions in this way can achieve the best compressive strength, further improve the stability of the grout-stopping wall, and ensure construction safety. The grout-stopping wall is as follows: Figure 3 As shown. After the construction of the grout-stopping wall is completed, a hole is drilled along the auxiliary pipe assembly 10 using a drill bit. During the drilling process, the drill bit will crush the auxiliary pipe assembly 10 to form a grouting pipe, and the fragments of the auxiliary pipe assembly 10 will be discharged from the grouting pipe. The wall of the grouting pipe is directly composed of the concrete 11.

[0076] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0077] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for constructing a grout-stopping wall for advanced construction of tunnels in high-pressure, water-rich fault zones, characterized in that, Includes the following steps: The thickness of the grout-stopping wall is calculated based on the grouting pressure, the dimensions of the tunnel cross-section, and the axial compressive strength of the concrete. A free surface is defined with the tunnel cross-section as the starting point and the thickness of the grout-stopping wall as the distance, and a pouring space is formed between the free surface and the tunnel cross-section; A first borehole group and a second borehole group are formed from top to bottom on the cross-section of the tunnel. The first borehole group forms a first height with the bottom of the tunnel cross-section, and the second borehole group forms a second height with the bottom of the tunnel. Both the first borehole group and the second borehole group include a plurality of evenly spaced boreholes. The first height is 38cm~42cm, the second height is 18cm~22cm, the diameter of the borehole is 100mm~120mm, and the depth of the borehole is 1m~2m. A first sandbag pile is constructed within the pouring space. A third height is formed between the top of the first sandbag pile and the bottom of the tunnel section. Using the first sandbag pile as support, a drainage steel pipe is inserted into the borehole. One end of the drainage steel pipe is inserted into the borehole, and the other end of the drainage steel pipe passes through the free surface and protrudes outside the pouring space. The third height is 60cm to 100cm. Several drainage holes are opened on the side wall of the drainage steel pipe near the tunnel section. The drainage holes are evenly distributed around the drainage steel pipe. The diameter of the drainage steel pipe is 100mm to 120mm, and the diameter of the drainage holes is 5mm to 12mm. A filling space is formed between the first sandbag pile and the tunnel section. A layer of crushed stone is filled into the filling space, and a second sandbag pile is laid on top of the crushed stone layer. A first steel mesh and a second steel mesh are erected within the pouring space. The first steel mesh is located on top of the second sandbag pile, and the second steel mesh abuts against the side of the first sandbag pile facing away from the gravel layer, so as to divide the pouring space from the tunnel section toward the free face into a first pouring area, a second pouring area and a third pouring area. An auxiliary pipe assembly is installed within the pouring space. One end of the auxiliary pipe assembly abuts against the roadway cross-section, and the other end of the auxiliary pipe assembly abuts against the free surface. The auxiliary pipe assembly includes a central auxiliary pipe, a first pipe assembly, and a second pipe assembly arranged sequentially from the inside out. The first pipe assembly includes several first inclined pipes arranged around the central auxiliary pipe, and the second pipe assembly includes several second inclined pipes arranged around the central auxiliary pipe. The central auxiliary pipe is parallel to the axis of the roadway cross-section. A first angle is formed between the first inclined pipe and the central auxiliary pipe, and a second angle is formed between the second inclined pipe and the central auxiliary pipe. The first angle is 5°~10°, and the second angle is 10°~20°. Concrete is poured sequentially in the first pouring area, the second pouring area, and the third pouring area to form a grout-stopping wall within the pouring space.

2. The method for constructing the grout-stopping wall for advanced construction of tunnels in high-pressure water-rich fault zones according to claim 1, characterized in that, The formula for calculating the thickness of the grout-stopping wall is as follows: ， in, Indicates the thickness of the grout-stopping wall. Indicates the safety factor. Indicates the grouting pressure. This represents the area of ​​the tunnel's cross-section. Indicates the width of the tunnel cross-section. Indicates the height of the tunnel cross section. It represents the axial compressive strength of concrete.

3. The method for constructing the grout-stopping wall for advanced construction of tunnels in high-pressure water-rich fault zones according to claim 1, characterized in that, The specific steps of constructing a first sandbag pile within the pouring space, forming a third height between the top of the first sandbag pile and the bottom of the tunnel cross-section, and inserting a drainage steel pipe into the borehole using the first sandbag pile as support, are as follows: A first sandbag pile is constructed within the pouring space along the width of the tunnel cross-section. When the height of the first sandbag pile reaches the second height, a drainage steel pipe is inserted into the borehole in the second borehole group; When the height of the first sandbag pile reaches the first height, the drainage steel pipe is inserted into the hole in the first drilling group; Continue piling up the first sandbag pile until a third height is formed between the top of the first sandbag pile and the bottom of the tunnel section.

4. The method for constructing the grout-stopping wall for advanced construction of tunnels in high-pressure water-rich fault zones according to claim 1, characterized in that, After the steps of forming a filling space between the first sandbag pile and the tunnel cross-section, filling the filling space with a layer of crushed stone, and laying a second sandbag pile on top of the crushed stone layer, the method further includes: A layer of fine sand is laid on the second sandbag pile.

5. The method for constructing a grout-stopping wall for advanced construction of tunnels in high-pressure, water-rich fault zones according to claim 1, characterized in that, The concrete is formed by mixing water, cement, NF-F composite admixture, BTS-1001 CSA high-performance expansive agent, polyvinyl alcohol fiber, imitation steel fiber, sand, and gravel. The mixing ratio of water, cement, NF-F composite admixture, BTS-1001 CSA high-performance expansive agent, polyvinyl alcohol fiber, imitation steel fiber, sand, and gravel is 166.1:410.0:130.0:32.8:1.1:5.0:616.0:1095.

1.

6. The method for constructing the grout-stopping wall for advanced construction of tunnels in high-pressure water-rich fault zones according to claim 1, characterized in that, After the step of defining the free face with the tunnel cross-section as the starting point and the thickness of the grout-stopping wall as the distance, and forming a pouring space between the free face and the tunnel cross-section, the method further includes: Several anchor bolts are inserted along the outer edge of the tunnel cross section, and a first interval is formed between adjacent anchor bolts.

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