A method of protecting and a protection structure for a tunnel substrate

Abstract

The application relates to a tunnel base protection method and a protection structure, which comprises the following steps: pouring prefabricated rapid-setting concrete slurry into a slurry-out area of a tunnel base surface to form a blocking layer; the blocking layer covers the surface of the slurry-out area; pouring prefabricated waterproof concrete slurry on the side, away from the tunnel base, of the blocking layer to form a waterproof layer; the edge of the waterproof layer exceeds the edge of the blocking layer; laying a reinforcing plate on the side, away from the waterproof layer, of the reinforcing plate and fixing the reinforcing plate to the tunnel base; pouring prefabricated sandstone concrete slurry on the side, away from the waterproof layer, of the reinforcing plate at least once to form at least one protection layer; and the edge of the protection layer exceeds the edge of the reinforcing plate, which can improve the reliability of the whole protection structure, effectively prevent slurry from seeping out, and guarantee the stability of the tunnel base structure.

Description

Technical Field

[0001] This application relates to the field of tunnel protection construction technology, and in particular to a method and structure for protecting the tunnel foundation. Background Technology

[0002] When constructing railway tunnels in water-rich areas, grout outlets may form in the tunnel foundation. These outlets can spew out mud and slurry, severely impacting the stability and normal use of the tunnel lining structure. Due to the uncertainties inherent in tunnel geotechnical engineering, effective design and construction control in water-rich areas is often impossible. Grout outlets are typically managed through a combination of prevention and control measures to ensure tunnel safety. However, existing methods are ineffective at sealing these outlets, resulting in limited prevention capabilities. Summary of the Invention

[0003] Therefore, it is necessary to provide a method and structure for protecting tunnel foundations to address the problem of poor prevention and control of grout outlets in existing tunnel foundations.

[0004] Firstly, a method for protecting a tunnel foundation is provided, the method comprising:

[0005] Precast quick-setting concrete grout is injected into the grout outlet area on the surface of the tunnel foundation to form a plugging layer; the plugging layer covers the surface of the grout outlet area.

[0006] A precast waterproof concrete grout is poured on the side of the plugging layer away from the tunnel foundation to form a waterproof layer; the edge of the waterproof layer extends beyond the edge of the plugging layer.

[0007] A reinforcing plate is laid on the side of the waterproof layer away from the blocking layer, and the reinforcing plate is fixed to the tunnel base;

[0008] At least one precast sand and gravel concrete grout is poured on the side of the reinforcing plate away from the waterproof layer to form at least one protective layer; the edge of the protective layer extends beyond the edge of the reinforcing plate.

[0009] In one embodiment, the step of laying a reinforcing plate on the side of the waterproof layer away from the blocking layer and fixing the reinforcing plate to the tunnel base includes:

[0010] Multiple reinforcement holes are drilled along the outer periphery of the waterproof layer at a location on the surface of the tunnel base corresponding to the outer side of the waterproof layer.

[0011] Expansive concrete grout is injected into each of the reinforcement holes, and one end of the pre-placed fixing column is inserted into the expansive concrete grout.

[0012] After the expansive concrete grout has solidified, the prefabricated reinforcing plate is laid on the side of the waterproof layer away from the blocking layer, and the reinforcing plate is fixed to the end of the fixing column away from the expansive concrete grout.

[0013] In one embodiment, the distance between the reinforcing hole and the edge of the slurry outlet area is greater than or equal to 2m;

[0014] The expansive concrete slurry comprises 0.5 to 2 parts of expansive agent, 4 to 6 parts of cement, and 5 to 7 parts of water.

[0015] In one embodiment, the step of pouring precast sand and gravel concrete grout at least once on the side of the reinforcing plate away from the waterproof layer to form at least one protective layer includes:

[0016] At least once, precast sand and gravel concrete grout is poured on the side of the reinforcing plate away from the waterproof layer;

[0017] After the sand and gravel concrete slurry reaches the preset solidification state, the sand and gravel concrete slurry is compacted to obtain at least one protective layer.

[0018] In one embodiment, the injection of precast quick-setting concrete grout into the grout-causing area on the surface of the tunnel foundation to form a plugging layer includes:

[0019] Determine the grout discharge area on the tunnel foundation surface;

[0020] Precast quick-setting concrete grout is injected into the grout outlet area until the grout outlet area meets the grout stopping condition;

[0021] After the concrete slurry reaches the preset solidification state, a blocking layer is obtained.

[0022] In one embodiment, the method further includes at least one of the following:

[0023] The thickness of the waterproof layer ranges from 5cm to 10cm;

[0024] The thickness of the protective layer is greater than or equal to 20cm.

[0025] In one embodiment, the method further includes at least one of the following:

[0026] The quick-setting concrete slurry comprises 2-4 parts quick-setting agent, 4-6 parts cement, and 4-6 parts water;

[0027] The waterproof concrete slurry comprises 1-3 parts waterproofing agent, 2-4 parts cement, and 3-5 parts water;

[0028] The sand and gravel concrete slurry comprises 2-4 parts fine sand, 3-5 parts cement, and 4-6 parts water.

[0029] Secondly, a protective structure for a tunnel foundation is provided, the protective structure comprising:

[0030] A blocking layer is formed on the surface of the tunnel base and covers the slurry discharge area on the surface of the tunnel base;

[0031] A waterproof layer is formed on the side of the plugging layer away from the tunnel base, and the edge of the waterproof layer extends outward beyond the edge of the plugging layer;

[0032] The reinforcement layer includes a reinforcement plate and multiple fixing columns. The reinforcement plate is laid on the side of the waterproof layer away from the blocking layer. The edge of the reinforcement plate forms an installation area that extends beyond the waterproof layer. The multiple fixing columns are distributed along the outer periphery of the slurry discharge area. One end of the fixing column is fixed to the tunnel foundation, and the end of the fixing column away from the tunnel foundation is fixed to the installation area.

[0033] A protective layer is formed on the side of the reinforcing layer away from the waterproof layer, and the edge of the protective layer extends outward beyond the edge of the reinforcing layer.

[0034] In one embodiment, a reinforcement hole is formed in the tunnel base corresponding to the position of the fixing column. The end of the reinforcement hole near the surface of the tunnel base has a first width, and the end of the reinforcement hole away from the surface of the tunnel base has a second width. The first width is less than or equal to the second width. The reinforcement hole is filled with expansive concrete grout, and the corresponding end of the fixing column is fixed in the reinforcement hole by the expansive concrete grout.

[0035] In one embodiment, the fixing column includes a pre-embedded section, a connecting section, and an anti-detachment section connected in sequence. The pre-embedded section is fixed in the reinforcement hole by the expansive concrete grout, and the diameter of the connecting section is smaller than the diameter of the anti-detachment section.

[0036] The reinforcing plate is provided with a clearance groove at the position corresponding to the installation area and a limiting groove arranged circumferentially next to the clearance groove. The limiting groove is connected to the clearance groove. The size of the clearance groove is adapted to the diameter of the anti-detachment section, and the size of the limiting groove is adapted to the diameter of the connecting section, so that the anti-detachment section passes through the clearance groove and the connecting section is limited in the limiting groove by moving the reinforcing plate.

[0037] The aforementioned method and structure for protecting the tunnel foundation involves injecting precast quick-setting concrete grout into the grout outlet area on the surface of the tunnel foundation to form a plugging layer; the plugging layer covers the surface of the grout outlet area; precast waterproof concrete grout is poured on the side of the plugging layer away from the tunnel foundation to form a waterproof layer; the edge of the waterproof layer extends beyond the edge of the plugging layer; a reinforcing plate is laid on the side of the waterproof layer away from the plugging layer and fixed to the tunnel foundation; precast sand and gravel concrete grout is poured at least once on the side of the reinforcing plate away from the waterproof layer to form at least one protective layer; the edge of the protective layer extends beyond the edge of the reinforcing plate. In the grouting area, a blocking layer is formed by injecting quick-setting concrete grout. Then, a waterproof layer and at least one protective layer are poured in sequence. A reinforcing plate is laid between the waterproof layer and the protective layer. This effectively prevents the grout from continuing to seep out, ensuring the stability of the tunnel foundation structure. At the same time, the edge of the waterproof layer extends beyond the blocking layer, which can further block the seepage of grout and groundwater. The reinforcing plate is placed between the waterproof layer and the blocking layer, and a protective layer is set outside the reinforcing plate. On the one hand, the reinforcing plate and the protective layer can effectively reduce the possibility of the blocking layer being washed away by the mud in the grouting area. On the other hand, the waterproof layer can effectively prevent the mud in the grouting area from coming into contact with the reinforcing plate after it is washed out of the blocking layer, preventing the reinforcing plate from rusting and corroding, thereby improving the reliability of the entire protective structure. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the protective structure of the tunnel foundation in one embodiment of this application.

[0039] Figure 2 This is a schematic diagram of the protective structure of the tunnel foundation in another embodiment of this application.

[0040] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0041] Figure 4 This is a structural schematic diagram of the reinforcing plate.

[0042] Figure 5 This is a flowchart of a method for protecting the tunnel foundation according to an embodiment of this application.

[0043] Instruction manual illustrations and reference numerals:

[0044] Tunnel base 10, grout discharge area 20, reinforcement hole 30, plugging layer 100, waterproof layer 200, reinforcement layer 300, reinforcement plate 310, clearance groove 311, limiting groove 312, fixing column 320, pre-embedded section 321, connecting section 322, anti-detachment section 323, protective layer 400. Detailed Implementation

[0045] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0046] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0047] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0049] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0050] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0051] like Figure 1 As shown, Figure 1 A schematic diagram of a protective structure for a tunnel foundation according to an embodiment of this application is shown. The protective structure for a tunnel foundation provided in an embodiment of this application includes a blocking layer 100, a waterproof layer 200, a reinforcing layer 300, and a protective layer 400. The blocking layer 100, the waterproof layer 200, the reinforcing layer 300, and the protective layer 400 are stacked sequentially to form a multi-layer protective structure on the slurry discharge area 20 of the tunnel foundation 10, so as to reduce the risk of slurry heave and mud discharge in the tunnel foundation 10 again.

[0052] A blocking layer 100 is formed on the surface of the tunnel base 10 and covers the slurry discharge area 20 on the surface of the tunnel base 10; a waterproof layer 200 is formed on the side of the blocking layer 100 away from the tunnel base 10, and the edge of the waterproof layer 200 extends outward beyond the edge of the blocking layer 100; a reinforcing layer 300 includes a reinforcing plate 310 and a plurality of fixing posts 320, the reinforcing plate 310 is laid on the side of the waterproof layer 200 away from the blocking layer 100, the edge of the reinforcing plate 310 forms an installation area that extends beyond the waterproof layer 200, the plurality of fixing posts 320 are distributed along the outer periphery of the slurry discharge area 20, one end of the fixing post 320 is fixed to the tunnel base 10, and the end of the fixing post 320 away from the tunnel base 10 is fixed to the installation area; a protective layer 400 is formed on the side of the reinforcing layer 300 away from the waterproof layer 200, and the edge of the protective layer 400 extends outward beyond the edge of the reinforcing layer 300.

[0053] The slurry seepage area 20 can be the area on the surface of the tunnel foundation 10 where slurry seeps out. The slurry seepage area 20 may be due to pores or cracks in the strata beneath the tunnel foundation 10, or insufficient waterproofing of the foundation structure, causing groundwater or other liquids carrying mud and other substances to seep to the surface of the tunnel foundation 10. In practice, the location and extent of the seepage in the slurry seepage area 20 can be determined through on-site observation and detection equipment (such as ground-penetrating radar, infrared thermal imagers, etc.).

[0054] A blocking layer 100 is formed on the slurry outlet area 20 to seal the area and prevent further seepage of mud. Specifically, pre-cast quick-setting concrete grout can be used to inject the slurry outlet area 20, and the blocking layer 100 is formed after the grout solidifies, thus sealing the area. In some embodiments, the surface of the blocking layer 100 away from the tunnel foundation 10 can be flush with the ground surface, i.e., flush with the opening or edge of the slurry outlet area 20. In other embodiments, during the forming process, the surface of the blocking layer 100 away from the tunnel foundation 10 can extend beyond the ground surface, and the edge of the blocking layer 100 can extend outward beyond the opening or edge of the slurry outlet area 20 to enhance the sealing effect against mud seepage, prevent slurry overflow, and ensure structural stability.

[0055] A waterproof layer 200 is formed on the side of the plugging layer 100 away from the slurry outlet area 20, which can further block the penetration of slurry and groundwater to achieve waterproofing of the plugging layer 100. Specifically, pre-prepared waterproof concrete slurry can be poured onto the side of the plugging layer 100 away from the slurry outlet area 20, and after the waterproof concrete slurry solidifies, the waterproof layer 200 is formed, covering the plugging layer 100 to achieve waterproofing. In some embodiments, the thickness of the waterproof layer 200 ranges from 5cm to 10cm, for example, 5cm, 6cm, 8cm, 10cm, or any value between these values, to ensure that the waterproof layer 200 has good waterproof performance and durability; the edge of the waterproof layer 200 can extend beyond the edge of the plugging layer 100 by a certain distance to avoid leakage due to inadequate edge sealing.

[0056] The reinforcing layer 300 is formed between the waterproof layer 200 and at least one protective layer 400. On the one hand, the reinforcing layer 300 can form a barrier above the waterproof layer 200 and the plugging layer 100 to reduce the risk of the plugging layer 100 and the waterproof layer 200 being washed away by the mud in the slurry outlet area 20, thereby further enhancing the barrier effect of the plugging layer 100 and the waterproof layer 200 against the mud. On the other hand, the reinforcing layer 300 can also support the protective layer 400 to ensure the overall structural strength of the protective structure. Furthermore, the reinforcing layer 300 can also disperse the force exerted by the protective layer 400 on the waterproof layer 200, the plugging layer 100, and the tunnel foundation 10 to balance the stress on the waterproof layer 200 and the plugging layer 100, thereby improving the overall lifespan and reliability of the protective structure. The reinforcement layer 300 includes a reinforcement plate 310 and multiple fixing columns 320. The reinforcement plate 310 is laid flat on the side of the waterproof layer 200 away from the blocking layer 100. The fixing columns 320 can be inserted through the reinforcement plate 310 to fix the reinforcement plate 310 to the tunnel foundation 10. This allows the corresponding side of the reinforcement plate 310 to fit tightly against the side of the waterproof layer 200 away from the blocking layer 100, thereby enhancing the stability of the waterproof layer 200. This prevents the waterproof layer 200 from separating from the tunnel foundation 10 and the blocking layer 100 due to external pressure or deformation, and also reduces the risk of mud washing away the blocking layer 100 and the waterproof layer 200 again, thus effectively ensuring the waterproof performance of the tunnel. In some embodiments, the reinforcement plate 310 can be implemented using a reinforcing steel plate, a reinforcing iron plate, or other plate-like structures with a certain structural strength.

[0057] In specific implementation, the edge of the reinforcing plate 310 extends beyond the edge of the waterproof layer 200, forming an installation area at the edge of the reinforcing plate 310. Multiple fixing posts 320 are distributed along the outer periphery of the slurry discharge area 20, and each fixing post 320 is correspondingly inserted into the reinforcing plate 310. One end of the fixing post 320 can be fixed to the tunnel base 10, while the end of the fixing post 320 away from the tunnel base 10 can be fixed to the installation area, ensuring stable installation of the reinforcing plate 310. Optionally, after the fixing posts 320 are installed, the distance between the projection of the center of each fixing post 320 onto the plane of the tunnel base 10 and the projection of the edge of the slurry discharge area 20 onto the plane of the tunnel base 10 is greater than or equal to 2m, such as 2m, 3m, 4m, or any value between these values. This ensures that the connection point between the fixing post 320 and the tunnel base 10 has sufficient distance from the edge of the slurry discharge area 20 to prevent the connection point from transmitting external forces to the edge of the slurry discharge area 20 during operation, thus preventing further expansion of the slurry discharge area 20.

[0058] At least one protective layer 400 is formed on the side of the reinforcing layer 300 away from the waterproof layer 200, such as including one protective layer 400 or two or three layers of protective layers 400 stacked together. In specific implementation, taking one protective layer 400 as an example, pre-made sand and gravel concrete grout can be poured into the side of the reinforcing plate 310 away from the waterproof layer 200. After the sand and gravel concrete grout has solidified to the preset solidification state, it is compacted. After the sand and gravel concrete grout has completely solidified, the protective layer 400 is formed to seal the blocking layer 100, the waterproof layer 200 and the reinforcing layer 300. When multiple protective layers 400 are set, the protective layers 400 can be formed layer by layer until the expected number of layers is reached. During the pouring and compaction process, the protective layer 400 can be evenly transferred to the waterproof layer 200 and the blocking layer 100 through the reinforcing plate 310, thereby compressing the waterproof layer 200 and the blocking layer 100 as a whole. This increases the structural density of the blocking layer 100 and the waterproof layer 200, further enhancing their sealing effect on the slurry outlet area 20 and reducing the risk of slurry outlet area 20 erupting again. In some embodiments, the thickness of the protective layer 400 is greater than or equal to 20 cm, such as 20 cm, 25 cm, 30 cm, or any value between these values, to ensure that the protective layer 400 has sufficient strength and durability, thus effectively resisting the erosion and damage of the external environment. The edge of the protective layer 400 can extend beyond the edge of the reinforcing layer 300 to completely seal the blocking layer 100, the waterproof layer 200, and the reinforcing layer 300, thereby further increasing the sealing effect of the protective structure.

[0059] The protective structure of the tunnel foundation in this embodiment comprises a blocking layer 100, a waterproof layer 200, a reinforcing layer 300, and at least one protective layer 400 stacked on the slurry outlet area 20. A reinforcing plate 310 is disposed between the waterproof layer 200 and the blocking layer 100, and a protective layer 400 is disposed outside the reinforcing plate 310. On the one hand, the reinforcing plate 310 and the protective layer 400 can effectively reduce the possibility of the blocking layer 100 being dispersed by the mud in the slurry outlet area 20. On the other hand, the waterproof layer 200 can effectively prevent the mud in the slurry outlet area 20 from contacting the reinforcing plate 310 after it flows out of the blocking layer 100, thus preventing the reinforcing plate 310 from rusting and corroding, thereby improving the reliability of the entire protective structure.

[0060] In one embodiment, such as Figure 2 and Figure 3As shown, a reinforcement hole 30 is formed in the tunnel base 10 at the position corresponding to the fixed column 320. The end of the reinforcement hole 30 near the surface of the tunnel base 10 has a first width, and the end of the reinforcement hole 30 away from the surface of the tunnel base 10 has a second width. The first width is less than or equal to the second width. The reinforcement hole 30 is filled with expansive concrete grout, and the corresponding end of the fixed column 320 is fixed in the reinforcement hole 30 by the expansive concrete grout.

[0061] The reinforcement hole 30 can be drilled in the tunnel foundation 10 using drilling equipment. Specifically, the reinforcement hole 30 can be drilled in the tunnel foundation 10 at a position more than 2m away from the edge of the grout outlet area 20 to accommodate and fix the corresponding fixing column 320. When drilling the reinforcement hole 30, the end of the reinforcement hole 30 closer to the surface of the tunnel foundation 10 is drilled smaller than the end farther from the surface of the tunnel foundation 10. That is, as shown in the figure, the reinforcement hole 30 has a trapezoidal structure that is smaller at the top and larger at the bottom. In this way, when the expansion concrete grout is filled into the reinforcement hole 30 to install the fixing column 320, after the expansion concrete grout has solidified, the inner wall of the reinforcement hole 30 can increase the tensile strength of the expansion concrete grout under external force, thereby increasing the installation strength of the fixing column 320. In other embodiments, the reinforcing hole 30 can also be configured with a multi-layered protrusion structure, that is, the inner wall of the reinforcing hole 30 is configured with a structure of alternating widths of different sizes, that is, the inner wall of the reinforcing hole 30 can be divided into multiple segments, and the cross-sectional view of each segment in the illustrated position can be configured as a trapezoidal structure to further increase the tensile strength of the expansive concrete grout under external force.

[0062] In an optional embodiment, the end of the fixing column 320 that is inserted into the expansive concrete grout can also be configured to resemble or be similar to the structure of the reinforcement hole 30. That is, the fixing column 320 can be configured with a larger size at one end near the bottom of the reinforcement hole 30 and a smaller size at the other end or in the middle. When the corresponding end of the fixing column 320 is inserted into the expansive concrete grout, it can be wrapped by the expansive concrete grout. After the expansive concrete grout solidifies, when the fixing column 320 receives an outward pull-out force, the pull-out force will be transmitted to the expansive concrete grout, so that the expansive concrete grout can form a barrier on the outer wall surface of the fixing column 320, thereby increasing the pull-out resistance of the fixing column 320. At the same time, under the pull-out force of the fixing column 320, the expansive concrete grout will also transmit the pull-out force to the side wall of the reinforcement hole 30, so that the side wall of the reinforcement hole 30 can form a barrier on the expansive concrete grout, thereby increasing the pull-out resistance of the expansive concrete grout. Thus, since the end of the fixed column 320 away from the reinforcement hole 30 is fixed to the reinforcement plate 310, when the reinforcement plate 310 is subjected to external force, the force can be transmitted step by step to the fixed column 320, the expansive concrete grout and the reinforcement hole 30. Through the multi-level pull-out resistance of the fixed column 320, the expansive concrete grout and the reinforcement hole 30, the reinforcement plate 310 can be prevented from separating from the fixed column 320, which is conducive to enhancing the overall structural strength and reliability of the protective structure.

[0063] In an optional embodiment, the reinforcing holes 30 can also be configured as columnar structures with uniform dimensions throughout the inner wall. The reinforcing holes 30 can be inclined, so that the fixing columns 320 can be inserted into the expansive concrete grout within the reinforcing holes 30 at an angle to increase the pull-out resistance of the fixing columns 320. Specifically, the inclination direction of the multiple reinforcing holes 30 can be radial, from the lower inside to the upper outside. Thus, when the reinforcing plate 310 is subjected to an oblique external force, for example, when the reinforcing plate 310 is subjected to a pull force to the upper left, except for the fixing column 320 corresponding to the upper left position, since the inclination direction of the fixing columns 320 and the reinforcing holes 30 at other positions is different from the inclination direction of the fixing column 320 corresponding to the upper left position, the fixing columns 320 at other positions can provide a reverse pull-out resistance to prevent the reinforcing plate 310 from detaching from the fixing columns 320.

[0064] In one embodiment, such as Figure 3 As shown, the fixed column 320 includes a pre-embedded section 321, a connecting section 322, and an anti-detachment section 323 connected in sequence. The pre-embedded section 321 is fixed in the reinforcement hole 30 by expanding concrete grout. The diameter of the connecting section 322 is smaller than the diameter of the anti-detachment section 323.

[0065] The embedded section 321 can be pre-embedded in the reinforcement hole 30 using expansive concrete grout. Specifically, after filling the reinforcement hole 30 with expansive concrete grout, the embedded section 321 of the fixing column 320 can be vertically or inclinedly inserted into the grout. Once the expansive concrete grout has solidified, the embedded section 321 will be fixed in the reinforcement hole 30. In an optional embodiment, the embedded section 321 can be configured with a smaller diameter at the end closer to the connecting section 322 and a larger diameter at the end farther from the connecting section 322, to improve the overall pull-out resistance of the fixing column 320 in conjunction with the expansive concrete grout. The anti-detachment section 323 is used to connect to the reinforcement plate 310. Specifically, the anti-detachment section 323 can be connected to the reinforcement plate 310 using bolts, clamping structures, etc.

[0066] In an optional embodiment, the fixing column 320 can be configured as a spindle-shaped structure, with the embedded section 321 and the anti-detachment section 323 being larger in size, while the connecting section 322 is smaller in size. This creates a fixing column 320 that is larger at both ends and smaller in the middle. After the embedded section 321 is inlaid with expansive concrete grout and the protective layer 400 is poured on top of the reinforcing plate 310, including the anti-detachment section 323, the expansive concrete grout can exert a downward restraining effect on the embedded section 321, while the protective layer 400 can exert an upward restraining effect on the anti-detachment section 323. This allows the expansive concrete grout and the protective layer 400 to exert a lateral force on the fixing column 320 as a whole, making the connection between the fixing column 320 and the expansive concrete grout and the protective layer 400 more stable and less prone to deformation.

[0067] Furthermore, such as Figure 4 As shown, the reinforcing plate 310 is provided with a clearance groove 311 at the position corresponding to the installation area and a limiting groove 312 arranged circumferentially next to the clearance groove 311. The limiting groove 312 is connected to the clearance groove 311. The size of the clearance groove 311 is adapted to the diameter of the anti-detachment section 323, and the size of the limiting groove 312 is adapted to the diameter of the connecting section 322, so that the anti-detachment section 323 passes through the clearance groove 311 and the connecting section 322 is limited in the limiting groove 312 by moving the reinforcing plate 310.

[0068] The reinforcing plate 310 can be circular, rectangular, or other polygonal structures, depending on the shape of the slurry outlet area 20. Taking a circular reinforcing plate 310 as an example, the size of the clearance groove 311 is adapted to the diameter of the anti-detachment section 323. The clearance groove 311 can be the same as or slightly larger than the diameter of the anti-detachment section 323. Similarly, the size of the limiting groove 312 is adapted to the diameter of the connecting section 322. The limiting groove 312 can be the same as or slightly larger than the diameter of the connecting section 322, but smaller than the diameter of the anti-detachment section 323. The diameter of the anti-detachment section 323 is such that it can pass through the clearance groove 311, allowing the reinforcing plate 310 to move after the connecting section 322 and the clearance groove 311 are at the same height. This allows the connecting section 322 to slide sideways into the limiting groove 312. Once the connecting section 322 is in place, because the size of the limiting groove 312 is smaller than the diameter of the anti-detachment section 323, the end of the anti-detachment section 323 near the connecting section 322 can abut against the corresponding surface of the reinforcing plate 310, preventing the reinforcing plate 310 from falling off the fixing post 320. Furthermore, the size of the clearance groove 311 can be slightly larger than the diameter of the anti-detachment section 323, and the size of the limiting groove 312 can be slightly larger than the diameter of the connecting section 322. This provides sufficient operating space during the assembly of the fixing plate and the fixing post 320, avoiding assembly difficulties or damage to components due to excessive tightness, while ensuring a stable and flexible connection after assembly.

[0069] Furthermore, since the relief groove 311 and the limiting groove 312 are set through the reinforcing plate 310, when the protective layer 400 is poured, the sand and gravel concrete slurry can flow into the relief groove 311 and the limiting groove 312, and after the sand and gravel concrete slurry solidifies, it forms an integral protective layer 400, which can further increase the positional reliability of the reinforcing plate 310 and prevent the reinforcing plate 310 from loosening.

[0070] In one example embodiment, such as Figure 5 As shown, a method for protecting a tunnel foundation is provided, which involves forming a protective structure as described in the above embodiment on the grout outlet region 20 of the surface of the tunnel foundation 10. The method of this embodiment includes steps 502 to 508, wherein:

[0071] Step 502: Inject precast quick-setting concrete grout into the grout outlet area 20 on the surface of the tunnel base 10 to form a plugging layer 100.

[0072] For example, the specific location of the grouting area 20 is determined on the surface of the tunnel foundation 10. For instance, the location and extent of the grouting area 20 can be determined with the assistance of on-site observation and detection equipment (such as ground-penetrating radar, infrared thermal imager, etc.). Then, pre-prepared quick-setting concrete grout is injected into the grouting area 20. After the quick-setting concrete grout solidifies, a blocking layer 100 is formed on the surface of the grouting area 20.

[0073] In an optional embodiment, the quick-setting concrete grout can be pre-prepared. The quick-setting concrete grout may include a quick-setting agent, cement, and water mixed in a certain proportion to allow for rapid solidification in a short time. Specifically, the quick-setting concrete grout may contain 2-4 parts quick-setting agent, 4-6 parts cement, and 4-6 parts water, by weight, so that after being poured into the grout outlet area 20, the quick-setting concrete grout can quickly fill the leakage channels, forming a plugging layer 100 to prevent further leakage. For example, when the quick-setting agent is 3 parts, the cement is 5 parts, and the water is 5 parts, the pre-prepared quick-setting concrete grout has good fluidity and quick-setting properties, achieving a grout-stopping effect in a short time.

[0074] Step 504: Pour precast waterproof concrete grout on the side of the blocking layer 100 away from the tunnel foundation 10 to form a waterproof layer 200.

[0075] For example, pre-made waterproof concrete grout is poured on the side of the plugging layer 100 away from the tunnel foundation 10, so that the waterproof concrete grout flows on the plugging layer 100 and flows outward a certain distance from the edge of the plugging layer 100, so that the waterproof concrete grout can completely cover the plugging layer 100. After the waterproof concrete grout solidifies, a waterproof layer 200 can be formed on the side of the plugging layer 100 away from the grout outlet area 20.

[0076] In an optional embodiment, the waterproof concrete grout can be pre-prepared. The waterproof concrete grout may comprise a waterproofing agent, cement, and water mixed in a specific ratio to form a waterproof layer 200 on the side of the plugging layer 100 away from the tunnel foundation 10. Specifically, the waterproof concrete grout may comprise 1-3 parts waterproofing agent, 2-4 parts cement, and 3-5 parts water, by weight, to improve the overall impermeability of the waterproof concrete grout and reduce the penetration of water and other liquids. For example, when the waterproofing agent is 2 parts, the cement is 3 parts, and the water is 4 parts, the waterproof concrete grout exhibits good waterproofing and workability.

[0077] In an optional embodiment, the thickness of the waterproof layer 200 is in the range of 5cm to 10cm, such as 5cm, 6cm, 8cm, 10cm or any value between these values, to ensure that the waterproof layer 200 can have good waterproof performance and durability; and the edge of the waterproof layer 200 can extend beyond the edge of the blocking layer 100 by a certain distance to avoid leakage due to poor edge sealing.

[0078] Step 506: Lay a reinforcing plate 310 on the side of the waterproof layer 200 away from the blocking layer 100, and fix the reinforcing plate 310 to the tunnel base 10.

[0079] For example, a reinforcing plate 310 is laid on the side of the solidified waterproof layer 200 away from the blocking layer 100, and the edge area of ​​the reinforcing plate 310 extending beyond the waterproof layer 200 is fixed to the tunnel base 10. For example, bolts or screws can be used to fix the reinforcing plate 310 to the tunnel base 10, or a snap-fit ​​structure can be used to fix the reinforcing plate 310 to the tunnel base 10.

[0080] In an optional embodiment, the reinforcing plate 310 can be implemented using a reinforcing steel plate, a reinforcing iron plate, or other plate-like structures with a certain structural strength. The specific structure of the reinforcing plate 310 can be found in the descriptions of the above embodiments, and will not be repeated in this embodiment.

[0081] Step 508: At least one precast sand and gravel concrete grout is poured on the side of the reinforcing plate 310 away from the waterproof layer 200 to form at least one protective layer 400; the edge of the protective layer 400 extends beyond the edge of the reinforcing plate 310.

[0082] For example, pre-prepared sand and gravel concrete grout is poured on the side of the reinforcing slab 310 away from the waterproof layer 200. The grout flows outwards from the edge of the reinforcing slab 310 a certain distance, completely covering it. After the grout solidifies, a protective layer 400 is formed on the side of the reinforcing slab 310 away from the waterproof layer 200. Depending on specific protection requirements, sand and gravel concrete grout can be repeatedly poured onto the formed protective layer 400 to create multiple protective layers 400.

[0083] In an optional embodiment, the aggregate concrete grout can be pre-prepared. The aggregate concrete grout may comprise fine sand, cement, and water mixed in a certain proportion to form a protective layer 400 on the side of the reinforcing slab 310 away from the waterproof layer 200. Specifically, the aggregate concrete grout may comprise 2-4 parts fine sand, 3-5 parts cement, and 4-6 parts water, by weight, to improve the overall structural strength of the aggregate concrete grout and enhance the protective performance of the protective layer 400. For example, when the fine sand content is 3 parts, the cement content is 4 parts, and the water content is 5 parts, the aggregate concrete grout exhibits better structural and workability properties.

[0084] In an optional embodiment, the thickness of the protective layer 400 is greater than or equal to 20 cm, such as 20 cm, 25 cm, 30 cm, or any value between these values, to ensure that the protective layer 400 has sufficient strength and durability to effectively resist erosion and damage from the external environment. The edge of the protective layer 400 may extend beyond the edge of the reinforcing layer 300 to completely seal the blocking layer 100, the waterproof layer 200, and the reinforcing layer 300, thereby further increasing the sealing effect of the protective structure. In specific implementation, when pouring multiple protective layers 400, the thickness of each protective layer 400 can be the same or different. Specifically, the amount of sand and gravel concrete grout used can be determined according to the protection requirements to obtain multiple protective layers 400 of different thicknesses.

[0085] The aforementioned method and structure for protecting the tunnel foundation involves injecting precast quick-setting concrete grout into the grout outlet area 20 on the surface of the tunnel foundation 10 to form a blocking layer 100; the blocking layer 100 covers the surface of the grout outlet area 20; precast waterproof concrete grout is poured on the side of the blocking layer 100 away from the tunnel foundation 10 to form a waterproof layer 200; the edge of the waterproof layer 200 extends beyond the edge of the blocking layer 100; a reinforcing plate 310 is laid on the side of the waterproof layer 200 away from the blocking layer 100 and fixed to the tunnel foundation 10; precast sand and gravel concrete grout is poured at least once on the side of the reinforcing plate 310 away from the waterproof layer 200 to form at least one protective layer 400; the edge of the protective layer 400 extends beyond the edge of the reinforcing plate 310. A blocking layer 100 is formed by injecting quick-setting concrete grout, followed by the sequential pouring of a waterproof layer 200 and at least one protective layer 400. A reinforcing plate 310 is laid between the waterproof layer 200 and the protective layer 400. This effectively prevents the grout from continuing to seep out, ensuring the structural stability of the tunnel foundation 10. Furthermore, the edge of the waterproof layer 200 extends beyond the blocking layer 100, further blocking the infiltration of grout and groundwater. The reinforcing plate 310 is positioned between the waterproof layer 200 and the blocking layer 100, with the protective layer 400 placed outside the reinforcing plate 310. On one hand, the reinforcing plate 310 and the protective layer 400 effectively reduce the possibility of the blocking layer 100 being dispersed by the mud in the grout outlet area 20. On the other hand, the waterproof layer 200 effectively prevents the mud in the grout outlet area 20 from contacting the reinforcing plate 310 after it flows out of the blocking layer 100, preventing the reinforcing plate 310 from rusting and corroding, thereby improving the reliability of the entire protective structure.

[0086] In one embodiment, in step 502, precast quick-setting concrete grout is injected into the grout outlet area 20 on the surface of the tunnel foundation 10 to form a plugging layer 100, including:

[0087] Determine the grouting area 20 on the surface of the tunnel foundation 10; inject precast quick-setting concrete grout into the grouting area 20 until the grouting area 20 meets the grouting stop condition; after the concrete grout reaches the preset solidification state, the plugging layer 100 is obtained.

[0088] For example, the surface of the tunnel foundation 10 can be inspected to determine the specific grouting area 20. Then, quick-setting agent, cement and water are mixed in the preset proportions to form quick-setting concrete grout. The quick-setting concrete grout is then injected into the grouting area 20 until the grouting area 20 no longer emits mud or grout. After that, the injection of quick-setting concrete grout is stopped, and the quick-setting concrete grout is allowed to solidify to the preset solidification state. If the quick-setting concrete grout has reached the preset solidification state, the strength is tested or the appearance is observed to determine whether the quick-setting concrete grout has reached the preset solidification state. If the quick-setting concrete grout has reached the preset solidification state, the blockage layer 100 is obtained.

[0089] In one optional embodiment, when determining the slurry outburst area 20, construction personnel can determine a general area based on experience, and then extend it outward by a certain distance (e.g., 30cm, 50cm, etc.) to obtain the slurry outburst area 20. This ensures that the slurry outburst area 20 fully covers the potentially leaking or reinforced areas, avoiding incomplete treatment due to insufficient area definition, and also improving the reliability and safety of construction. In other embodiments, ground-penetrating radar or infrared thermal imagers can also be used to detect the slurry outburst location of the tunnel foundation 10 to determine the specific slurry outburst area 20.

[0090] In one embodiment, step 506 involves laying a reinforcing plate 310 on the side of the waterproof layer 200 away from the blocking layer 100 and fixing the reinforcing plate 310 to the tunnel base 10, including:

[0091] At a location on the surface of the tunnel foundation 10 corresponding to the outer side of the waterproof layer 200, multiple reinforcement holes 30 are drilled along the outer periphery of the waterproof layer 200; expansive concrete grout is injected into each reinforcement hole 30, and one end of a pre-installed fixing column 320 is inserted into the expansive concrete grout; after the expansive concrete grout has solidified, a prefabricated reinforcement plate 310 is laid on the side of the waterproof layer 200 away from the blocking layer 100, and the reinforcement plate 310 is fixed to the end of the fixing column 320 away from the expansive concrete grout.

[0092] The tunnel base 10 has a reinforcement hole 30 at the location corresponding to the fixing column 320. The end of the reinforcement hole 30 near the surface of the tunnel base 10 has a first width, and the end of the reinforcement hole 30 away from the surface of the tunnel base 10 has a second width. The first width is less than or equal to the second width. The reinforcement hole 30 is filled with expansive concrete grout, and the corresponding end of the fixing column 320 is fixed in the reinforcement hole 30 by the expansive concrete grout. The fixing column 320 includes a pre-embedded section 321, a connecting section 322, and an anti-detachment section 323 connected in sequence. The pre-embedded section 321 is fixed in the reinforcement hole 30 by the expansive concrete grout, and the diameter of the connecting section 322 is smaller than the diameter of the anti-detachment section 323. The reinforcing plate 310 has a clearance groove 311 at a position corresponding to the installation area and a limiting groove 312 arranged circumferentially beside the clearance groove 311. The limiting groove 312 communicates with the clearance groove 311. The size of the clearance groove 311 is adapted to the diameter of the anti-detachment section 323, and the size of the limiting groove 312 is adapted to the diameter of the connecting section 322, so that the anti-detachment section 323 passes through the clearance groove 311 and the connecting section 322 is limited within the limiting groove 312 by moving the reinforcing plate 310. The specific structure of the reinforcing plate 310 and the fixing post 320 can be referred to the description in the above embodiment, and will not be repeated in this embodiment.

[0093] For example, a reinforcing plate 310 of appropriate size is selected according to the size of the waterproof layer 200 or the grout discharge area 20, and a clearance groove 311 and a limiting groove 312 are drilled on the reinforcing plate 310. At the same time, according to the position of the clearance groove 311 and the limiting groove 312 on the reinforcing plate 310, a reinforcing hole 30 corresponding to the position of the clearance groove 311 or the limiting groove 312 is drilled along the outer periphery of the waterproof layer 200 on the surface of the tunnel foundation 10 at the position corresponding to the outer side of the waterproof layer 200. Then, expansive concrete grout is injected into the reinforcement holes 30, and the pre-embedded section 321 of the pre-placed fixing column 320 is inserted vertically or obliquely into the expansive concrete grout. After the expansive concrete grout solidifies, the reinforcement plate 310 is placed above the waterproof layer 200, and the relief groove 311 is aligned with the anti-detachment section 323 of the fixing column 320. The reinforcement plate 310 is then laid on the side of the waterproof layer 200 away from the blocking layer 100, so that the anti-detachment section 323 passes through the relief groove 311. The reinforcement plate 310 is then rotated so that the connecting section 322 enters the limiting groove 312 to fix the reinforcement plate 310. In some other embodiments, bolts can also be used to further fix the fixing column 320.

[0094] In an optional embodiment, the expansive concrete grout can be pre-prepared. The expansive concrete grout may include an expansive agent, cement, and water mixed in a certain proportion to pre-embed the embedded section 321 of the fixing column 320 within the reinforcing hole 30, thereby fixing the fixing column 320. Specifically, the expansive concrete grout may contain 0.5-2 parts of expansive agent, 4-6 parts of cement, and 5-7 parts of water, by weight, to ensure that the expansive concrete grout expands appropriately during the hardening process, filling the gap between the fixing column 320 and the reinforcing hole 30 and enhancing the bonding strength. For example, when the expansive agent is 1 part, the cement is 5 parts, and the water is 6 parts, the expansive concrete grout has good expansion performance and structural stability, effectively preventing the fixing column 320 from loosening.

[0095] In an optional embodiment, the distance between the reinforcing hole 30 and the edge of the slurry outlet area 20 is greater than or equal to 2m (i.e., the distance between the center of the fixing column 320 and the edge of the slurry outlet area 20 is greater than or equal to 2m), such as 2m, 3m, 4m or any value between these values, so that when drilling the reinforcing hole 30, it can be at a sufficient distance from the edge of the slurry outlet area 20 to prevent the reinforcing hole 30 from transmitting external forces to the edge of the slurry outlet area 20 during the drilling process, thereby causing the slurry outlet area 20 to expand further.

[0096] In one embodiment, in step 508, at least one precast aggregate concrete grout is poured on the side of the reinforcing plate 310 away from the waterproof layer 200 to form at least one protective layer 400, including:

[0097] At least one precast sand and gravel concrete grout is poured on the side of the reinforcing plate 310 away from the waterproof layer 200; after the sand and gravel concrete grout reaches the preset solidification state, the sand and gravel concrete grout is compacted to obtain at least one protective layer 400.

[0098] For example, taking a protective layer 400 as an example, fine sand, cement and water are mixed in a preset ratio to obtain a sand and gravel concrete slurry. Then, the sand and gravel concrete slurry is poured onto the side of the reinforcing plate 310 away from the waterproof layer 200. After the sand and gravel concrete slurry solidifies to the preset solidification state, if the sand and gravel concrete slurry no longer flows actively without external force, a road roller is used to compact the sand and gravel concrete slurry. During the compaction process, the blocking layer 100, the waterproof layer 200 and the reinforcing plate 310 can be squeezed again. After the sand and gravel concrete slurry is completely solidified, the protective layer 400 is obtained.

[0099] In other embodiments, if it is necessary to cast multiple protective layers 400, the above steps can be repeated to form the protective layers 400 layer by layer.

[0100] The following section uses specific examples to illustrate methods for protecting tunnel foundations.

[0101] In one application example, the method for protecting the tunnel foundation includes the following steps:

[0102] S11. On the tunnel foundation 10, identify the slurry discharge area 20 where mud and slurry are seeping out. Use pre-prepared quick-setting concrete grout to grout the slurry discharge area 20 until the continuous slurry discharge from the slurry discharge area 20 stops. After the quick-setting concrete grout has completely solidified, a plugging layer 100 is formed. The quick-setting concrete grout is made by mixing quick-setting agent, cement, and water, wherein the quick-setting agent is 3 parts, cement is 5 parts, and water is 5 parts.

[0103] S12. Apply waterproof concrete grout to the side of the plugging layer 100 away from the grout outlet area 20 to form a waterproof layer 200 with a thickness of 5 cm. The waterproof concrete grout is made by mixing waterproofing agent, cement, and water, wherein the waterproofing agent is 2 parts, the cement is 3 parts, and the water is 4 parts.

[0104] S13. Drill reinforcement holes 30 around the outer perimeter of the waterproof layer 200, inject expansive concrete grout into the reinforcement holes 30, and insert fixing columns 320. When drilling reinforcement holes 30, the distance between the reinforcement holes 30 and the edge of the grout outlet area 20 is 2m. The expansive concrete grout is made by mixing an expansive agent, cement, and water, wherein the expansive agent is 1 part, the cement is 5 parts, and the water is 6 parts.

[0105] S14. After the expansive concrete grout has solidified, place the reinforcing plate 310 on the side of the waterproof layer 200 away from the blocking layer 100. Bolt holes are provided on the reinforcing plate 310. The fixing column 320 is passed through the bolt holes and tightened with nuts.

[0106] S15. Pour a 20cm thick layer of sand and gravel concrete grout on the side of the fixed column 320 and the reinforcing plate 310 away from the waterproof layer 200. The sand and gravel concrete grout is made of fine sand, cement, and water, with 3 parts fine sand, 4 parts cement, and 5 parts water. After 1 hour, use a road roller to compact the sand and gravel concrete grout to form the first protective layer 400.

[0107] S16. On the side of the first protective layer 400 away from the reinforcing plate 310, pour a 20cm thick layer of sand and gravel concrete grout. The composition of the sand and gravel concrete grout is the same as in step S15. One hour later, use a road roller to compact the sand and gravel concrete grout to form the second protective layer 400.

[0108] S17. On the side of the second protective layer 400 away from the first protective layer 400, pour a 20cm thick layer of sand and gravel concrete grout. The composition of the sand and gravel concrete grout is the same as in step S15. One hour later, use a road roller to compact the sand and gravel concrete grout to form the third protective layer 400, thus completing the protection treatment for the mudslide at the tunnel foundation 10.

[0109] In another application example, the method for protecting the tunnel foundation includes the following steps:

[0110] S21. On the tunnel foundation 10, identify the slurry discharge area 20 where mud and slurry are seeping out. Use pre-prepared quick-setting concrete grout to grout the slurry discharge area 20 until the continuous slurry discharge from the slurry discharge area 20 stops. After the quick-setting concrete grout has completely solidified, a plugging layer 100 is formed. The quick-setting concrete grout is made by mixing quick-setting agent, cement, and water, wherein the quick-setting agent is 3 parts, cement is 5 parts, and water is 5 parts.

[0111] S22. Apply waterproof concrete grout to the side of the plugging layer 100 away from the grout outlet area 20 to form a waterproof layer 200 with a thickness of 8 cm. The waterproof concrete grout is made by mixing waterproofing agent, cement, and water, wherein the waterproofing agent is 2 parts, the cement is 3 parts, and the water is 4 parts.

[0112] S23. Drill reinforcement holes 30 around the outer perimeter of the waterproof layer 200, inject expansive concrete grout into the reinforcement holes 30, and insert fixing columns 320. When drilling reinforcement holes 30, the distance between the reinforcement holes 30 and the edge of the grout outlet area 20 is 3m. The expansive concrete grout is made by mixing an expansive agent, cement, and water, wherein the expansive agent is 1 part, the cement is 5 parts, and the water is 6 parts.

[0113] S24. After the expansive concrete grout has solidified, place a reinforcing plate 310 on the side of the waterproof layer 200 away from the blocking layer 100. Bolt holes are provided on the reinforcing plate 310. The fixing column 320 is passed through the bolt holes and tightened with nuts.

[0114] S25. Pour a 25cm thick layer of sand and gravel concrete grout on the side of the fixed column 320 and the reinforcing plate 310 away from the waterproof layer 200. The sand and gravel concrete grout is made of fine sand, cement, and water, with 3 parts fine sand, 4 parts cement, and 5 parts water. After 1 hour, use a road roller to compact the sand and gravel concrete grout to form the first protective layer 400.

[0115] S26. On the side of the first protective layer 400 away from the reinforcing plate 310, pour a 25cm thick layer of sand and gravel concrete grout. The composition of the sand and gravel concrete grout is the same as in step S25. One hour later, use a road roller to compact the sand and gravel concrete grout to form the second protective layer 400.

[0116] S27. On the side of the second protective layer 400 away from the first protective layer 400, pour a 25cm thick layer of sand and gravel concrete grout. The composition of the sand and gravel concrete grout is the same as in step S25. One hour later, use a road roller to compact the sand and gravel concrete grout to form the third protective layer 400, thus completing the protection treatment for the mudslide at the tunnel foundation 10.

[0117] In yet another application example, the method for protecting the tunnel foundation includes the following steps:

[0118] S31. On the tunnel foundation 10, identify the slurry discharge area 20 where mud and sludge are seeping out. Use pre-prepared quick-setting concrete grout to grout the slurry discharge area 20 until the continuous slurry discharge from the slurry discharge area 20 stops. After the quick-setting concrete grout has completely solidified, a plugging layer 100 is formed. The quick-setting concrete grout is made by mixing quick-setting agent, cement, and water, wherein the quick-setting agent is 3 parts, cement is 5 parts, and water is 5 parts.

[0119] S32. Apply waterproof concrete grout to the side of the plugging layer 100 away from the grout outlet area 20 to form a waterproof layer 200 with a thickness of 10cm. The waterproof concrete grout is made by mixing waterproofing agent, cement, and water, wherein the waterproofing agent is 2 parts, the cement is 3 parts, and the water is 4 parts.

[0120] S33. Drill reinforcement holes 30 around the outer perimeter of the waterproof layer 200, inject expansive concrete grout into the reinforcement holes 30, and insert fixing columns 320; when drilling reinforcement holes 30, the distance between the reinforcement holes 30 and the edge of the grout outlet area 20 is 4m. The expansive concrete grout is made by mixing expansive agent, cement, and water, wherein the expansive agent is 1 part, the cement is 5 parts, and the water is 6 parts.

[0121] S34. After the expansive concrete grout has solidified, place a reinforcing plate 310 on the side of the waterproof layer 200 away from the blocking layer 100. Bolt holes are provided on the reinforcing plate 310. The fixing column 320 is passed through the bolt holes and tightened with nuts.

[0122] S35. Pour a 30cm thick layer of sand and gravel concrete grout on the side of the fixed column 320 and the reinforcing plate 310 away from the waterproof layer 200. The sand and gravel concrete grout is made of fine sand, cement, and water, with 3 parts fine sand, 4 parts cement, and 5 parts water. After 1 hour, use a road roller to compact the sand and gravel concrete grout to form the first protective layer 400.

[0123] S36. On the side of the first protective layer 400 away from the reinforcing plate 310, pour a 30cm thick layer of sand and gravel concrete grout. The composition of the sand and gravel concrete grout is the same as in step S35. One hour later, use a road roller to compact the sand and gravel concrete grout to form the second protective layer 400.

[0124] S37. On the side of the second protective layer 400 away from the first protective layer 400, pour a 30cm thick layer of sand and gravel concrete grout. The composition of the sand and gravel concrete grout is the same as in step S35. One hour later, use a road roller to compact the sand and gravel concrete grout to form the third protective layer 400, thus completing the protection treatment for the mudslide at the tunnel foundation 10.

[0125] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for protecting the foundation of a tunnel, characterized in that, The method includes: Precast quick-setting concrete grout is injected into the grout outlet area on the surface of the tunnel foundation to form a plugging layer; the plugging layer covers the surface of the grout outlet area. A precast waterproof concrete grout is poured on the side of the plugging layer away from the tunnel foundation to form a waterproof layer; the edge of the waterproof layer extends beyond the edge of the plugging layer. A reinforcing plate is laid on the side of the waterproof layer away from the blocking layer, and the reinforcing plate is fixed to the tunnel base; At least one precast sand and gravel concrete grout is poured on the side of the reinforcing plate away from the waterproof layer to form at least one protective layer; the edge of the protective layer extends beyond the edge of the reinforcing plate.

2. The method according to claim 1, characterized in that, The step of laying a reinforcing plate on the side of the waterproof layer away from the blocking layer and fixing the reinforcing plate to the tunnel foundation includes: Multiple reinforcement holes are drilled along the outer periphery of the waterproof layer at a location on the surface of the tunnel base corresponding to the outer side of the waterproof layer. Expansive concrete grout is injected into each of the reinforcement holes, and one end of the pre-placed fixing column is inserted into the expansive concrete grout. After the expansive concrete grout has solidified, the prefabricated reinforcing plate is laid on the side of the waterproof layer away from the blocking layer, and the reinforcing plate is fixed to the end of the fixing column away from the expansive concrete grout.

3. The method according to claim 2, characterized in that, The distance between the reinforcement hole and the edge of the slurry outlet area is greater than or equal to 2m; The expansive concrete slurry comprises 0.5 to 2 parts of expansive agent, 4 to 6 parts of cement, and 5 to 7 parts of water.

4. The method according to claim 1, characterized in that, The process of pouring precast sand and gravel concrete grout at least once on the side of the reinforcing plate away from the waterproof layer to form at least one protective layer includes: At least once, precast sand and gravel concrete grout is poured on the side of the reinforcing plate away from the waterproof layer; After the sand and gravel concrete slurry reaches the preset solidification state, the sand and gravel concrete slurry is compacted to obtain at least one protective layer.

5. The method according to claim 1, characterized in that, The process of injecting precast quick-setting concrete grout into the grout-producing area on the surface of the tunnel foundation to form a plugging layer includes: Determine the grout discharge area on the tunnel foundation surface; Precast quick-setting concrete grout is injected into the grout outlet area until the grout outlet area meets the grout stopping condition; After the concrete slurry reaches the preset solidification state, a blocking layer is obtained.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes at least one of the following: The thickness of the waterproof layer ranges from 5cm to 10cm; The thickness of the protective layer is greater than or equal to 20cm.

7. The method according to any one of claims 1 to 5, characterized in that, The method further includes at least one of the following: The quick-setting concrete slurry comprises 2-4 parts quick-setting agent, 4-6 parts cement, and 4-6 parts water; The waterproof concrete slurry comprises 1-3 parts waterproofing agent, 2-4 parts cement, and 3-5 parts water; The sand and gravel concrete slurry comprises 2-4 parts fine sand, 3-5 parts cement, and 4-6 parts water.

8. A protective structure for a tunnel foundation, characterized in that, The protective structure includes: A blocking layer is formed on the surface of the tunnel base and covers the slurry discharge area on the surface of the tunnel base; A waterproof layer is formed on the side of the plugging layer away from the tunnel base, and the edge of the waterproof layer extends outward beyond the edge of the plugging layer; The reinforcement layer includes a reinforcement plate and multiple fixing columns. The reinforcement plate is laid on the side of the waterproof layer away from the blocking layer. The edge of the reinforcement plate forms an installation area that extends beyond the waterproof layer. The multiple fixing columns are distributed along the outer periphery of the slurry discharge area. One end of the fixing column is fixed to the tunnel foundation, and the end of the fixing column away from the tunnel foundation is fixed to the installation area. A protective layer is formed on the side of the reinforcing layer away from the waterproof layer, and the edge of the protective layer extends outward beyond the edge of the reinforcing layer.

9. The protective structure according to claim 8, characterized in that, A reinforcement hole is formed in the tunnel base corresponding to the position of the fixed column. The end of the reinforcement hole near the surface of the tunnel base has a first width, and the end of the reinforcement hole away from the surface of the tunnel base has a second width. The first width is less than or equal to the second width. The reinforcement hole is filled with expansive concrete grout, and the corresponding end of the fixed column is fixed in the reinforcement hole by the expansive concrete grout.

10. The structure according to claim 9, characterized in that, The fixed column includes a pre-embedded section, a connecting section, and an anti-detachment section connected in sequence. The pre-embedded section is fixed in the reinforcement hole by the expansive concrete grout. The diameter of the connecting section is smaller than the diameter of the anti-detachment section. The reinforcing plate is provided with a clearance groove at the position corresponding to the installation area and a limiting groove arranged circumferentially next to the clearance groove. The limiting groove is connected to the clearance groove. The size of the clearance groove is adapted to the diameter of the anti-detachment section, and the size of the limiting groove is adapted to the diameter of the connecting section, so that the anti-detachment section passes through the clearance groove and the connecting section is limited in the limiting groove by moving the reinforcing plate.

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