Drainage anchor rod, slope drainage system and method for treating slope drainage of under-crossing slope tunnel

Abstract

The application provides a drainage anchor rod, a slope drainage system and a slope drainage treatment method for a tunnel passing through a slope, and belongs to the technical field of tunnel slope treatment, and comprises an anchor rod body and a drainage inner pipe; the anchor rod body is provided with a central hole arranged in the axial direction, and a plurality of water permeable holes in communication with the central hole are further arranged on the anchor rod body; the drainage inner pipe is supported in the anchor rod body through an inner pipe framework, and a plurality of drainage holes in communication with the central hole are arranged on the drainage inner pipe; a plurality of drainage anchor rods, drainage branch pipes corresponding to each row of drainage anchor rods, and drainage main pipes corresponding to both sides of the tunnel bottom; during construction, the lengthened drainage anchor rod is driven into the surrounding rock near the sliding surface at the selected position; and the ordinary drainage anchor rod and the ordinary anchor rod are alternately arranged. The slope treatment method provided by the application integrates anchoring and drainage, ensures the stability of the slope, and ensures the safety of the tunnel; the effective combination of slope drainage and anchoring can reduce the construction process, reduce the construction cost and shorten the construction period.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tunnel slope treatment, and particularly relates to a drainage anchor rod, a slope drainage system, and a slope treatment method for realizing slope drainage of a tunnel passing through a slope. BACKGROUND

[0002] A bias tunnel is formed due to asymmetric terrain or geological stratum factors, causing asymmetric loads on both sides of the tunnel structure. When the tunnel entrance is located on an unstable hillside with poor terrain conditions, and the soil layer thickness on both sides of the tunnel top is seriously inconsistent, it is a bias phenomenon. If not properly handled, the tunnel may crack and collapse in severe cases. When the pressure on one side of the tunnel is too high, the stress on the tunnel structure is uneven, and local stress concentration and excessive deformation may lead to shear failure of the tunnel structure.

[0003] In the scenario of a tunnel passing through a slope, especially when the volume of the tunnel and the slope is close, effective treatment of the slope is of great significance to the stability and safety of the tunnel.

[0004] The principle of slope prevention is prevention first and treatment second. At present, there are mainly the following methods for slope treatment:

[0005] Drainage: An annular water interception ditch is set on the perimeter of the landslide area, a platform drainage ditch and a drainage hole are set on the landslide slope, forming an organic whole, and the surface water infiltration is minimized to lower the underground water level and reduce the influence of underground water on the physical and mechanical properties of rock-soil mass.

[0006] Slope anchoring: A rod made of metal, wood, polymer or other materials is driven into a pre-drilled hole in the surface rock mass or surrounding rock mass of the chamber, and the surrounding rock and stable rock mass are combined together by the special structure of the head, rod body and tail plate (which can also be omitted) or relying on the bonding effect to produce a suspension effect, a composite beam effect, a reinforcement effect to achieve the purpose of support.

[0007] Mechanical balance method: such as setting retaining walls, anti-slide piles, slope reduction, and other measures.

[0008] The slope treatment and protection has certain effect on common tunnel slope, but tunnel underpass slope treatment is different from common slope, and the special points are as follows: (1) the existence of tunnel structure changes the internal mechanical properties of the slope, and the effectiveness of the traditional slope treatment method of setting anti-slide piles and the like is difficult to measure for different engineering conditions; (2) the existing common slope treatment means separates drainage and anchoring, thereby increasing the construction cost; (3) for the slope underpass described in the patent, the existence of the tunnel can help the slope, and the drainage and anchoring can be combined; (4) the existence of the tunnel under the slope makes the traditional slope treatment structures such as anti-slide piles, anchor rods and retaining walls possibly unable to reach the design depth; (5) for the slope with a bias pressure tunnel, the construction of the deep drainage pipeline by the open cut method can disturb the soil, destroy the slope stability and increase the construction risk. SUMMARY

[0009] The embodiment of the present application provides a drainage anchor rod, a slope drainage system and a tunnel slope drainage treatment method underpassing a slope, which integrates drainage and anchoring, and aims at reliably and effectively treating the drainage of the tunnel underpassing the slope.

[0010] To achieve the above object, the technical scheme adopted by the present application is as follows: a drainage anchor rod is provided, comprising:

[0011] an anchor rod body having a central hole arranged in the axial direction, and a plurality of water permeable holes communicating with the central hole are further arranged on the anchor rod body; and

[0012] a drainage inner pipe supported in the anchor rod body through an inner pipe framework, and a plurality of drainage holes communicating with the central hole are arranged on the drainage inner pipe.

[0013] In combination with the first aspect, in a possible implementation manner, a fiber mesh for filtration is coated on the outer wall of the drainage inner pipe.

[0014] In combination with the first aspect, in a possible implementation manner, a bottom is arranged on the inner port of the drainage inner pipe, the outer end of the drainage inner pipe extends out of the anchor rod body, and has a radially expanded connecting pipe section.

[0015] In combination with the first aspect, in a possible implementation manner, the anchor rod body comprises an anchoring head, an anchor rod outer pipe and an anchor rod connecting piece connected in sequence, the inner end of the drainage inner pipe abuts against the inner end face of the anchoring head, and the outer end of the drainage inner pipe is radially expanded and threadedly connected with the anchor rod connecting piece.

[0016] In combination with the first aspect, in a possible implementation manner, a waterproof rubber ring is arranged in the anchor rod connecting piece, and a connecting hole is further arranged around the anchor rod connecting piece.

[0017] With reference to the first aspect, in a possible implementation manner, the anchor rod body further comprises a waterproof rubber plug, which is sleeved on one end of the anchor rod outer tube connected with the anchor rod connector.

[0018] With reference to the first aspect, in a possible implementation manner, the waterproof rubber plug is in a conical structure.

[0019] With reference to the first aspect, in a possible implementation manner, the anchor rod body is provided with annular grooves and annular ridges alternately along the axial direction, and the annular grooves and the annular ridges are both provided with the water permeable holes.

[0020] The second aspect, the embodiment of the present application further provides a slope drainage system of a tunnel passing through a slope, comprising:

[0021] A plurality of the drainage anchor rods, the drainage anchor rods are arranged in multiple rows along the length direction of the tunnel, and the drainage anchor rods in each row are arranged in a fan shape along the radial direction of the tunnel;

[0022] A drainage branch pipe corresponding to each row of the drainage anchor rods, the drainage branch pipe is in an arch structure and is arranged in the tunnel in a random shape, and the drainage inner tube of each drainage anchor rod is connected to the drainage branch pipe; and

[0023] A drainage main pipe corresponding to both sides of the bottom of the tunnel, both ends of each drainage branch pipe are connected to the drainage main pipe in parallel.

[0024] The third aspect, the embodiment of the present application further provides a slope drainage treatment method of a tunnel passing through a slope, based on the slope drainage system of the tunnel passing through the slope, the method comprises:

[0025] Determining a potential sliding surface of the slope after the tunnel passes through by using a numerical simulation technology;

[0026] Determining the length and arrangement position of the lengthened drainage anchor rod and the ordinary drainage anchor rod according to the distance between the sliding surface and the anchor point of the anchor rod;

[0027] After the initial lining layer of the tunnel is hardened, the lengthened drainage anchor rod is driven into the surrounding rock near the sliding surface at the selected position; at the same time, the ordinary drainage anchor rod and the ordinary anchor rod are arranged alternately;

[0028] Fixing the lengthened drainage anchor rod, the ordinary drainage anchor rod and the ordinary anchor rod on the initial lining layer;

[0029] Filling the water permeable aggregate into the lengthened drainage anchor rod and the ordinary drainage anchor rod and sealing and compacting;

[0030] Filling the water permeable aggregate into the lengthened drainage anchor rod and the ordinary drainage anchor rod and sealing and compacting;

[0031] Installing the drainage branch pipe, and fixing the drainage branch pipe on the initial lining layer at a certain interval;

[0032] Multiple protective supports are evenly distributed around the outer edge of each drainage branch pipe to protect it.

[0033] A main drainage pipe is laid on both sides of the bottom of the tunnel, and the branch drainage pipes are connected to the main drainage pipe;

[0034] Geotextile was laid for secondary tunnel lining.

[0035] The slope treatment method for slope drainage using an underpass tunnel provided by this invention has the following advantages compared with the prior art: It utilizes drainage anchors, which have both anchoring and drainage functions, to combine the self-anchoring and waterproofing structure of the specially constructed underpass tunnel. This process drains the slope, lowers the groundwater level inside the slope, and achieves the purpose of slope treatment. It integrates tunnel and slope drainage, ensuring slope stability and tunnel safety. The effective combination of slope drainage and anchoring also reduces construction procedures, lowers construction costs, is highly efficient and convenient, shortens the construction period, and has strong overall integrity.

[0036] During slope treatment construction, extended drainage anchors are designed based on the depth and location of the potential sliding surface of the underpass slope. Ordinary drainage anchors and regular anchors can be installed in other locations. In this way, the combination of extended drainage anchors, ordinary drainage anchors and regular anchors can achieve slope drainage at different depths. It can also utilize the strength of ordinary anchors to improve the reliability of the drainage system anchorage, thereby improving the effectiveness and stability of the slope drainage treatment of the underpass slope tunnel. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a drainage anchor provided in an embodiment of the present invention;

[0038] Figure 2 This is a partial structural schematic diagram of the anchor bolt outer tube provided in an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the main structure of the anchor bolt connector provided in an embodiment of the present invention;

[0040] Figure 4 for Figure 3 Cross-sectional view of the provided anchor bolt connector;

[0041] Figure 5 For along Figure 1 Sectional view of the middle AA line;

[0042] Figure 6 This is a schematic diagram of the drainage inner pipe used in an embodiment of the present invention;

[0043] Figure 7 A diagram showing the arrangement of drainage anchors provided in an embodiment of the present invention;

[0044] Figure 8 This is a schematic diagram of the structure of the protective bracket provided in an embodiment of the present invention;

[0045] Explanation of reference numerals in the attached figures:

[0046] 1. Anchor head; 2. Anchor bolt outer tube; 21. Annular concave groove; 22. Annular convex groove; 23. Water-permeable hole; 3. Waterproof rubber plug; 4. Anchor bolt connector; 41. Connecting hole; 42. Waterproof rubber gasket; 43. Waterproof rubber ring; 5. Drainage inner pipe; 51. Connecting pipe section; 52. Conical transition section; 53. Drainage hole; 6. Inner pipe skeleton; 61. Support rod; 62. Circular ring; 7. Permeable aggregate; 8. Drainage branch pipe; 9. Protective bracket; 91. Arc-shaped bracket; 92. Connecting plate; 93. Connecting rod; 10. Drainage main pipe. Detailed Implementation

[0047] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0048] Please refer to the following: Figures 1 to 6 The drainage anchor provided by the present invention will now be described. The drainage anchor includes: an anchor body and a drainage inner pipe 5; the anchor body has a central hole arranged along the axial direction, and the anchor body is also provided with a plurality of water-permeable holes 23 communicating with the central hole; the drainage inner pipe 5 is supported in the anchor body by an inner pipe skeleton 6, and the drainage inner pipe 5 is provided with a plurality of drainage holes 53 communicating with the central hole.

[0049] Compared with existing technologies, the drainage anchor provided in this embodiment utilizes the self-anchoring and drainage functions of the drainage anchor to combine self-anchoring with waterproofing structure for tunnels with special structures underpass slopes. This process drains the slope, lowers the groundwater level inside the slope, and achieves the purpose of slope control. It realizes the integration of tunnel and slope drainage, ensuring the stability of the slope and the safety of the tunnel, while reducing construction risks. The effective combination of slope drainage and anchoring also reduces construction procedures, lowers construction costs, is highly efficient and convenient, shortens the construction period, and has strong overall integrity.

[0050] Water is a crucial factor affecting slope stability. Studies have found that when the rate of water level decline within the slope lags behind that outside, outward seepage is a significant cause of slope instability. Furthermore, the anti-sliding force provided by the soil and rock mass below the waterline gradually decreases as the water level in the foundation pit rises. Therefore, comprehensive landslide prevention and control schemes, encompassing drainage and support, can improve the stability of such slopes. This embodiment proposes a better approach to managing tunnels under slopes by altering the conditions for slope slippage and improving the properties of the sliding surface, particularly by changing the slope's water content.

[0051] Among them, such as Figure 1 and Figure 2 As shown, the permeable holes 23 on the anchor bolt body are evenly distributed, and the drainage holes 53 on the drainage inner pipe 5 are evenly distributed. These two types of holes can be circular, elongated, or polygonal, without limitation. Water in the surrounding rock enters the drainage inner pipe 5 through the permeable holes 23 and drainage holes 53, and then flows from the drainage inner pipe 5 along the drainage branch pipe 8 and out of the drainage main pipe 10.

[0052] In some embodiments, to prevent gravel in the rock strata from entering the inner drainage pipe 5 through the drainage hole 53 and causing long-term blockage of the drainage pipe, a fiber mesh for filtration is wrapped around the outer wall of the inner drainage pipe 5 to achieve a filtration effect. This embodiment is not shown in the figure.

[0053] Optionally, such as Figure 5 and Figure 6 As shown, the inner tube skeleton 6 includes a ring 62 and multiple support rods 61 radially connected to the ring 62. Multiple inner tube skeletons 6 are evenly arranged along the axial direction of the anchor rod body to support the drainage inner tube 5 and improve the strength of the anchor rod. The drainage inner tube 5 passes through the ring 62 and its inner end abuts against the anchor head 1.

[0054] In some embodiments, such as Figure 1 and Figure 6 As shown, the inner port of the drainage inner pipe 5 is sealed, and the outer end of the drainage inner pipe 5 extends out of the anchor rod body and has a radially expanding connecting pipe section 51. The sealing of the inner port of the drainage inner pipe 5 can also be achieved by directly sealing the end face of the anchoring end of the anchor rod body, which can prevent sand and gravel from entering from the inner end of the drainage inner pipe 5 and ensure that water enters the drainage inner pipe 5 through the drainage hole 53 via the fiber mesh. At the same time, the outer end of the drainage inner pipe 5 extends out of the anchor rod body, which facilitates the guidance and discharge of drainage and also facilitates the connection of the drainage inner pipe 5 to the drainage system.

[0055] Optionally, such as Figure 6 As shown, a tapered transition section 52 can be provided at the outer end of the inner drainage pipe 5 to connect to the radially expanding connecting pipe section 51. The connecting pipe section 51 is a round pipe to facilitate connection to the drainage system.

[0056] In some embodiments, such as Figures 1 to 3As shown, the anchor bolt body includes an anchor head 1, an outer anchor pipe 2, and an anchor bolt connector 4 connected in sequence. The inner end of the drainage inner pipe 5 abuts against the inner end face of the anchor head 1, and the outer end of the drainage inner pipe 5 expands radially and is threadedly connected to the anchor bolt connector 4. The anchor head 1 can be a drill bit, which facilitates the anchor bolt being driven into the surrounding rock; the outer anchor pipe 2 is gripped tightly against the inner wall of the anchor hole to ensure reliable anchor bolt fixation; the anchor bolt connector 4 is flange-shaped, which facilitates fixation to the inner wall of the tunnel. At the same time, the anchor bolt connector 4 also serves as a seal to block the anchor hole, ultimately exposing the outer end of the drainage inner pipe 5.

[0057] In some embodiments, such as Figure 4 As shown, the anchor bolt connector 4 has a waterproof rubber ring 43 inside, and connection holes 41 are also provided around the anchor bolt connector 4. The waterproof rubber ring between the anchor bolt connector 4 and the drainage inner pipe 5 serves to seal between the anchor bolt outer pipe 2 and the drainage inner pipe 5; the connection holes 41 facilitate fixing the anchor bolt to the inner wall of the tunnel. Regarding the setting of the waterproof rubber ring, generally an annular groove is set on the outer wall of the drainage inner pipe, and the waterproof rubber ring is partially embedded in the annular groove. At the same time, corresponding annular grooves can be set on the inner wall of the anchor bolt connector or the corresponding anchor bolt outer pipe to achieve the positioning of the waterproof rubber ring. No example is given in the figure.

[0058] As another implementation of the anchor bolt body, such as Figure 1 As shown, the anchor bolt connector and the outer anchor bolt tube are separate structures. That is, the anchor bolt connector and the outer anchor bolt tube are not fixedly connected, but rather connected to the drainage inner pipe via a screw thread. When anchoring the drainage anchor bolt, first drive the outer anchor bolt tube into the anchor hole, then insert the drainage inner pipe into the inner pipe frame, and then insert the waterproof plug into the outer end of the outer anchor bolt tube, sealing the anchor hole. Then, put on the anchor bolt connector and rotate it inward until the anchor bolt connector squeezes the waterproof plug and contacts the tunnel wall.

[0059] Note that the waterproof plug has a certain length reserved outward so that the anchor bolt connector can be pressed against to form an elastic seal.

[0060] At this time, as Figure 4 As shown, a waterproof gasket 42 can also be installed between the anchor bolt connector 4 and the tunnel wall to improve the sealing effect; the waterproof rubber ring 43 can also be fitted into the groove on the side of the anchor bolt connector 4 facing the waterproof rubber plug. After the anchor bolt connector 4 is installed in place, the waterproof rubber ring 43 and the waterproof rubber plug 3 will make contact through compression, achieving a better sealing effect. The anchor bolt connector is as follows... Figure 4 As shown. It should be noted that the waterproof gasket and waterproof rubber ring may not be classified as anchor bolt connectors. In other words, the anchor bolt connection assembly includes anchor bolt connectors, waterproof gaskets, and waterproof rubber rings. Therefore, the issue of component classification does not constitute a limitation on this embodiment.

[0061] like Figure 1As shown, based on the above embodiments, the anchor bolt body provided in this embodiment also includes a waterproof plug 3, which is fitted onto the end where the anchor bolt outer tube 2 connects to the anchor bolt connector 4. The waterproof plug 3 ensures a sealed connection between the anchor bolt body and the anchor hole.

[0062] Optionally, such as Figure 1 As shown, the waterproof rubber stopper 3 has a conical structure to achieve a tight seal.

[0063] As an improved implementation method for the anchor bolt body, such as Figure 1 and Figure 2 As shown, the anchor bolt body is provided with alternating annular concave patterns 21 and annular convex patterns 22 along the axial direction, and both the annular concave patterns 21 and the annular convex patterns 22 are provided with water-permeable holes 23. The annular concave patterns 21 and annular convex patterns 22 are designed to increase the water-cutting area, improve the gripping force of the anchor bolt body, and enhance the reliability of the anchoring.

[0064] To further improve the holding power of the anchor bolt, such as Figure 2 As shown, the annular concave pattern 21 has multiple raised friction ribs along its circumference. The cross-sections of the annular concave pattern 21 and the annular raised pattern 22 are arc-shaped.

[0065] Regarding the shape of the permeable holes 23, optionally, round holes are provided on the annular concave ridges 21, and oblong holes are provided on the annular convex ridges 22. The combination of different hole shapes improves water permeability.

[0066] The drainage anchor bolt provided in this embodiment has an anodized outer tube 2 to enhance its corrosion resistance. The drainage inner tube 5 is made of PVC, with an artificial fiber mesh attached to its outer side and supported by an inner tube skeleton 6. The artificial fiber mesh serves to guide water and prevent aggregate from sliding down, while the inner tube skeleton 6 supports the drainage inner tube 5.

[0067] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0068] Based on the same inventive concept, such as Figure 7 As shown in the figure, this application embodiment also provides a slope drainage system for a tunnel passing under a slope, including: multiple drainage anchors, drainage branch pipes 8 corresponding to each row of drainage anchors, and drainage main pipes 10 corresponding to both sides of the bottom of the tunnel.

[0069] The drainage anchors are arranged in multiple rows along the length of the tunnel, and each row of drainage anchors is arranged radially along the tunnel. The drainage branch pipe 8 corresponding to each row of drainage anchors has an arched structure and is set in the tunnel according to the shape. The drainage inner pipe 5 of each drainage anchor is connected to the drainage branch pipe 8. The two ends of each drainage branch pipe 8 are connected in parallel to the drainage main pipe 10 on both sides of the bottom of the tunnel.

[0070] Water collected through the permeable hole 23 of the outer pipe 2 of the anchor bolt enters the inner drainage pipe 5, and flows through the branch drainage pipe 8 into the main drainage pipe 10 for discharge.

[0071] As an optional implementation method, such as Figure 7 and Figure 8 As shown, multiple protective supports 9 are evenly distributed around the outer circumference of each drainage branch pipe 8 to protect it. These protective supports 9 can be made of plastic, which is not easy to rust and is flexible and easy to bend. The drainage branch pipes 8 and the main drainage pipe 10 can also be made of PVC, which is not easy to rust and is durable.

[0072] This invention also provides a method for slope drainage treatment of tunnels passing under slopes. Based on the slope drainage system of the tunnel, the method mainly includes four steps: design of the length and placement of drainage anchors; installation of drainage anchors; laying of the drainage system; and laying of the overall waterproof geotextile.

[0073] like Figure 7 As shown, the detailed process flow is as follows:

[0074] Step one, the design of the length and placement of the drainage anchor bolts, is carried out during the tunnel design phase. Its purpose is to determine the placement of ordinary drainage anchor bolts and extended drainage anchor bolts.

[0075] Specifically, a finite element model of the tunnel and slope is first established, and numerical simulation technology is used to determine the potential sliding surface of the slope after the tunnel passes under it. The length and placement of the extended drainage anchor and the ordinary drainage anchor are determined based on the distance between the sliding surface and the anchor point.

[0076] Step two, the installation of drainage anchor bolts, is carried out simultaneously with the installation of anchor bolts after the initial lining of the tunnel is completed.

[0077] The process can be summarized into four steps: positioning, pipe installation, filling, and fixing. Positioning involves marking the installation location of the drainage anchors according to the design. Pipe installation involves driving the specially treated drainage anchors into the surrounding rock. Filling involves filling the driven drainage anchors with permeable aggregate 7 and sealing and compacting it. Fixing involves fixing the drainage anchors filled with aggregate onto the initial support layer, i.e., the initial lining layer, to stabilize the drainage anchors. A waterproof rubber plug 3 and an anchor connector 4 are installed at the fixing end.

[0078] The specific procedure is as follows: After the initial lining layer of the tunnel hardens, extended drainage anchors are driven into the surrounding rock near the sliding surface at the selected location; at the same time, ordinary drainage anchors and ordinary anchors are laid alternately.

[0079] The extended drainage anchor, ordinary drainage anchor, and ordinary anchor are fixed to the primary lining layer.

[0080] Inject water into the extended drainage anchor bolts and ordinary drainage anchor bolts until water flows out;

[0081] Fill the extended drainage anchor bolts and ordinary drainage anchor bolts with permeable aggregate 7 and seal and compact it.

[0082] Among them, the permeable aggregate 7 is made of single-grade coarse sand and mixed with a small amount of super absorbent polymer material to make permeable mortar. After the assembly is completed, water only needs to be injected into the drainage pipe 5 to realize its later filling and water collection functions. Compared with the traditional grouting process, the high-pressure grouting step is not required, which simplifies the construction process.

[0083] Step 3: Install drainage branch pipe 8 and drainage main pipe 10.

[0084] Step 8, laying drainage branch pipes, is carried out after the drainage anchor bolts are installed. Each level of drainage branch pipe 8 is installed on the outer end of the drainage anchor bolts, and simultaneously, the main drainage pipe 10 is laid, with one main drainage pipe 10 on each side of the tunnel. Each level of drainage branch pipe 8 is then connected in parallel to the main drainage pipe 10. The drainage branch pipes 8 are fixed to the primary lining layer at regular intervals using pipe clamps. After this step is completed, the drainage system is finished.

[0085] Specifically, multiple protective supports 9 are evenly distributed circumferentially around the outer edge of each drainage branch pipe 8 to protect the drainage branch pipe 8 and prevent pipe deformation caused by secondary lining. The protective supports 9 are fixed to the primary lining layer and include parallel arc-shaped supports 91 and connecting rods 93 connecting the arc-shaped supports 91 to improve support strength. The arc-shaped supports 91 are connected together to improve overall integrity. Connecting plates 92 can also be installed at both ends of the arc-shaped supports 91, and the arc-shaped supports 91 are then fixed to the primary lining layer through the connecting plates 92. Heat-shrink gaskets are installed on the protective supports 9 to compensate for displacement changes caused by thermal expansion and contraction.

[0086] Step four: Lay geotextile for secondary tunnel lining.

[0087] The integral geotextile laying is a step in the tunnel waterproofing process. This method lays the geotextile waterproof layer outside the drainage system, isolating slope seepage water and slope drainage together outside the main tunnel structure, thus achieving integrated slope drainage and anchoring. The geotextile is laid along the undulations of the protective support 9 and the primary lining layer to ensure that the protective support 9 protects the drainage inner pipe 5.

[0088] The slope drainage treatment method provided by this invention involves designing extended drainage anchors based on the depth and location of the potential sliding surface of the underpass slope during slope treatment construction. Ordinary drainage anchors and regular anchors can be installed at other locations. In this way, the combination of extended drainage anchors, ordinary drainage anchors, and regular anchors can achieve slope drainage at different depth levels. It can also utilize the strength of ordinary anchors to improve the reliability of the drainage system's anchorage, thereby improving the effectiveness and stability of slope drainage treatment for underpass tunnels.

[0089] The treatment method provided by this invention utilizes the self-anchoring and drainage functions of drainage anchors. It combines self-anchoring with a waterproof structure for specially constructed underpass slope tunnels to drain the slope, lowering the internal groundwater level and achieving the goal of slope treatment. This integrates tunnel and slope drainage, ensuring slope stability and the safety of tunnel construction and operation. The effective combination of slope drainage and anchoring also reduces construction procedures, lowers construction costs, and is highly efficient, convenient, and shortens the construction period.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A drainage anchor bolt, characterized in that, include: The anchor bolt body has a central hole arranged along the axial direction, and the anchor bolt body is also provided with a plurality of water-permeable holes (23) communicating with the central hole; and The drainage inner pipe (5) is supported in the anchor rod body by the inner pipe skeleton (6), and the drainage inner pipe (5) is provided with a plurality of drainage holes (53) that are connected to the central hole; The anchor body includes an anchor head (1), an anchor outer tube (2), and an anchor connector (4) connected in sequence. The inner end of the drainage inner tube (5) abuts against the inner end face of the anchor head (1), and the outer end of the drainage inner tube (5) expands radially and is threadedly connected to the anchor connector (4). The space between the outer pipe (2) of the anchor bolt and the inner pipe (5) is filled with permeable aggregate (7) and then sealed and compacted. The anchor body is provided with alternating annular concave patterns (21) and annular convex patterns (22) along the axial direction, and the annular concave patterns (21) and annular convex patterns (22) are provided with water-permeable holes (23); The annular concave pattern (21) has multiple raised friction ribs along its circumferential direction; wherein the cross-sections of the annular concave pattern (21) and the annular convex pattern (22) are arc-shaped structures. The inner tube skeleton (6) includes a ring (62) and a plurality of support rods (61) radially connected to the ring (62). A plurality of inner tube skeletons (6) are uniformly arranged along the axial direction of the anchor body to support the drainage inner tube (5) and improve the strength of the anchor. The drainage inner tube (5) passes through the ring (62) and its inner end abuts against the top anchor head (1). A slope treatment method employing the aforementioned drainage anchor bolts and utilizing an underpass tunnel to achieve slope drainage includes: Numerical simulation techniques were used to determine the potential sliding surface of the slope after the tunnel passes under it. The length and placement of the extended drainage anchor and the ordinary drainage anchor are determined based on the distance between the sliding surface and the anchor point. After the initial lining layer of the tunnel hardens, extended drainage anchors are driven into the surrounding rock near the sliding surface at selected locations; at the same time, ordinary drainage anchors are laid alternately with ordinary anchors. The extended drainage anchor, ordinary drainage anchor, and ordinary anchor are fixed to the primary lining layer. Inject water into the extended drainage anchor bolts and ordinary drainage anchor bolts until water flows out; Fill the extended drainage anchor bolts and ordinary drainage anchor bolts with permeable aggregate (7) and seal and compact them; Install drainage branch pipes (8) and fix the drainage branch pipes (8) on the primary lining layer at regular intervals; Multiple protective supports (9) are evenly distributed around the outer edge of each drainage branch pipe (8) to protect the drainage branch pipe (8); Drainage main pipes (10) are laid on both sides of the bottom of the tunnel, and drainage branch pipes (8) are connected to drainage main pipes (10); Geotextile was laid for secondary tunnel lining.

2. The drainage anchor bolt as described in claim 1, characterized in that, The outer wall of the drain inner pipe (5) is covered with a fiber mesh for filtration.

3. The drainage anchor bolt as described in claim 1, characterized in that, The inner port of the drainage inner pipe (5) is sealed, the outer end of the drainage inner pipe (5) extends out of the anchor rod body, and has a radially expanding connecting pipe section (51).

4. The drainage anchor bolt as described in claim 1, characterized in that, The anchor bolt connector (4) is provided with a waterproof rubber ring, and the anchor bolt connector (4) is also provided with connection holes (41) around its perimeter.

5. The drainage anchor bolt as described in claim 1, characterized in that, The anchor body also includes a waterproof rubber plug (3), which is fitted onto the end of the anchor outer tube (2) that connects to the anchor connector (4).

6. The drainage anchor bolt as described in claim 5, characterized in that, The waterproof rubber plug (3) has a conical structure.

7. A slope drainage system for a tunnel passing under a slope, characterized in that, include: Multiple drainage anchors as described in any one of claims 1-6, wherein the drainage anchors are arranged in multiple rows along the length of the tunnel, and the drainage anchors in each row are arranged radially along the tunnel. Corresponding to each row of drainage anchors, the drainage branch pipe (8) has an arched structure and is installed within the tunnel in a conformal manner. The drainage inner pipe (5) of each drainage anchor is connected to the drainage branch pipe (8); and Corresponding to the main drainage pipes (10) on both sides of the bottom of the tunnel, the two ends of each of the drainage branch pipes (8) are connected in parallel to the main drainage pipes (10).

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