Drainage structure for single-hole double-track tunnel to pass through water-rich fault fracture zone
By designing a multi-layer drainage structure and filtering device in a single-hole double-line tunnel, the problem of drainage pipe blockage is solved, and efficient tunnel drainage and structural protection is achieved.
Patent Information
- Application Number
- CN202421016999.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-11
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-05-11
AI Technical Summary
During the drainage process of tunnel, existing drainage pipes will discharge sediment and other debris into the drainage ditch, blocking the drainage ditch and affecting the drainage effect, especially in the central drainage ditch setting, which is difficult to clean.
A drainage structure for single-hole double-line tunnel passing through the water-rich fault breaking zone, including blind ditch, side drain ditch, central drain ditch, drain pipe and water collection well. A filter device is provided at the upper end of the drain pipe, and the water collection well is in the water collection well. Backfill the graded gravel, and an iron sand mesh is installed at the lower end of the drain pipe to filter impurities. There is a roof plate that can be opened and closed at the top of the central drainage ditch for easy cleaning.
Improve the drainage efficiency and effect of tunnel ring and surrounding rock at the bottom of the tunnel, avoid damage to the tunnel arch, realize full drainage of tunnel ring upward, reduce water erosion on the tunnel structure, and ensure long-term smoothness of drainage ditch .
Smart Images
Figure CN222228617U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of tunnel drainage, in particular to a drainage structure used for a single-hole double-line tunnel passing through a water-rich fault fracture zone. Background Art
[0002] Traditional drainage measures in tunnel engineering usually use a combination of blind ditches and drainage ditches for drainage. In water-rich fault zones, due to the high groundwater level, it is also necessary to set up drainage pipes in the surrounding rock at the bottom of the tunnel. The water at the bottom of the tunnel is introduced into the drainage ditch through the drainage pipe to drain the groundwater under the tunnel invert. The combination of circumferential drainage and drainage under the invert can improve drainage efficiency and drainage effect. However, during the drainage process, the existing drainage pipes will discharge debris such as mud and sand into the drainage ditch, blocking the drainage ditch and affecting the drainage effect. Especially when a central drainage ditch is set, it is difficult to clean the central drainage ditch because a middle partition wall will be set on the central drainage ditch. Utility Model Content
[0003] The utility model aims to provide a drainage structure for a single-hole double-track tunnel crossing a water-rich fault fracture zone, thereby overcoming the disadvantage that the existing drainage pipe will discharge the mud and sand and other debris in the surrounding rock at the bottom of the tunnel into the drainage ditch along with the water flow, thereby blocking the drainage ditch and affecting the drainage effect.
[0004] To achieve the above-mentioned purpose, the utility model provides a drainage structure for a single-hole double-track tunnel crossing a water-rich fault fracture zone, comprising: a blind ditch, a plurality of the blind ditches are spaced apart along the length direction of the tunnel, each of the blind ditch is in an arch shape corresponding to the tunnel contour line, and each of the blind ditch is located between the primary lining and the surrounding rock; a side drainage ditch, one of the side drainage ditches is provided on each side of the tunnel bottom surface, the length of each of the side drainage ditch is distributed along the length direction of the tunnel, and each of the side drainage ditch is located on the inner side of the secondary lining; a first drainage pipe, each of the two ends of each of the blind ditch is connected to the corresponding side drainage ditch through one of the first drainage pipes; a central drainage ditch, which is arranged on the tunnel bottom surface and located on the tunnel centerline, and the length of the central drainage ditch is distributed along the length direction of the tunnel; a second drainage pipe, each of the side drainage ditches is connected to the central drainage ditch through the second drainage pipe; a first drainage pipe, each of the side drainage ditches is connected to the central drainage ditch through the second drainage pipe; The side drainage ditch is provided with a plurality of first drainage pipes distributed at intervals along its length direction, the upper end of each first drainage pipe is communicated with the corresponding side drainage ditch, and the upper end opening of the first drainage pipe is located in the middle and upper part of the corresponding side drainage ditch; second drainage pipe, the central drainage ditch is provided with a plurality of second drainage pipes distributed at intervals along its length direction, the upper end of each second drainage pipe is communicated with the central drainage ditch; wherein the upper end opening of the second drainage pipe is located in the middle and upper part of the central drainage ditch, and the upper end of the second drainage pipe is provided with a filtering device; and water collection wells, the surrounding rock at the bottom of the tunnel is provided with the water collection wells at the position corresponding to each first drainage pipe and at the position corresponding to each second drainage pipe, the lower end of each first drainage pipe and the lower end of each second drainage pipe are respectively downwardly penetrated through the second lining and the primary lining of the invert arch and extend downward into the corresponding water collection wells.
[0005] Preferably, in the above technical solution, the filtering device includes a filter chamber and a top cover, the filter chamber is provided at the top of the second drain pipe, the diameter of the filter chamber is larger than the outer diameter of the second drain pipe, and a filter net is provided between the filter chamber and the upper end opening of the second drain pipe; the top of the filter chamber is open, and the top opening of the filter chamber is provided with the openable and closable top cover, and the top cover is provided with a plurality of drainage holes distributed at intervals; wherein, the filter chamber is filled with filtering material.
[0006] Preferably, in the above technical solution, a middle partition wall is provided on the center line of the tunnel, and a reserved channel is provided on the middle partition wall at a position corresponding to each of the second drainage pipes, and an openable and closable top plate is provided on the top of the central drainage ditch at a position corresponding to each of the second drainage pipes.
[0007] Preferably, in the above technical solution, a plurality of water inlet holes distributed in a plum blossom shape and connected to the corresponding water collection wells are provided on the lower end side wall of the first drainage pipe; a plurality of water inlet holes distributed in a plum blossom shape and connected to the corresponding water collection wells are provided on the lower end side wall of the second drainage pipe.
[0008] Preferably, in the above technical solution, the lower end opening and the side wall water inlet holes of the first drain pipe are wrapped with iron sand mesh, and the lower end opening and the side wall water inlet holes of the second drain pipe are also wrapped with iron sand mesh.
[0009] Preferably, in the above technical solution, the water collection well is backfilled with graded crushed stone.
[0010] Preferably, the above technical solution also includes a water retaining plate, and a water retaining plate is provided between the surrounding rock at the bottom of the tunnel and the primary lining of the invert arch. The lower end of each of the first drainage pipes and the lower end of each of the second drainage pipes successively penetrate downward through the secondary lining of the invert arch, the primary lining of the invert arch and the water retaining plate and extend downward into the corresponding water collection well.
[0011] Preferably, in the above technical solution, an expansion water stop ring is provided between each of the first drain pipes and the water baffle plate, and between each of the second drain pipes and the water baffle plate.
[0012] Preferably, in the above technical solution, the inlet of the first drain pipe is connected to the middle of the side wall of the corresponding side drain ditch.
[0013] Preferably, in the above technical solution, a plastic film and an iron window screen are sequentially provided between the blind ditch and the primary lining from the outside to the inside.
[0014] Compared with the prior art, the utility model has the following beneficial effects:
[0015] 1. The drainage structure of the utility model can be used to combine drainage of the tunnel circumferentially and the surrounding rock at the bottom of the tunnel, which is particularly suitable for areas with high water levels in water-rich areas to improve drainage effects and efficiency. The structure in which a water collecting well, a first drainage pipe and two side drainage ditches are connected, combined with a structure in which a water collecting well, a second drainage pipe and a central drainage ditch are connected, can further improve the drainage efficiency and effect of the surrounding rock at the bottom of the tunnel, avoid damage to the tunnel invert, achieve full drainage of the tunnel circumferentially, and reduce water erosion of the tunnel structure. The central drainage ditch is not easy to clean, and a filtering device is provided at the upper end of the second drainage pipe. On the one hand, it can filter fine sand and gravel in the water to avoid clogging of the central drainage ditch after long-term use, thereby ensuring drainage effects. On the other hand, it can also reduce the impact of water and alleviate the impact of scouring on the central drainage ditch. The side drainage ditch is easy to clean, and a filtering device may not be provided at the top of the first drainage pipe.
[0016] 2. In the drainage structure of the utility model, a reserved channel is provided on the middle partition wall at a position corresponding to each second drain pipe, and an openable and closable top plate is provided on the top of the central drainage ditch at a position corresponding to each second drain pipe, so as to facilitate replacement and cleaning of the filter device on the second drain pipe, avoid blockage of the filter device, and ensure drainage effect.
[0017] 3. The water collection well of the utility model is backfilled with graded crushed stone to filter the coarse sand and slow down the flow, thereby performing primary filtration of the groundwater; the lower end opening and the water inlet holes of the side wall of the first drainage pipe are wrapped with iron sand mesh, and the lower end opening and the water inlet holes of the side wall of the second drainage pipe are wrapped with iron sand mesh, which can perform secondary filtration of the groundwater and avoid clogging the drainage pipe and the filtering device.
[0018] 4. The drainage structure of the utility model also includes a water retaining plate, which is arranged between the surrounding rock at the bottom of the tunnel and the primary lining of the invert arch, so as to separate the surrounding rock at the bottom of the tunnel and the primary lining of the invert arch and reduce the influence of groundwater on the tunnel structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 The utility model is a schematic structural diagram of a drainage structure for a single-hole double-line tunnel passing through a water-rich fault fracture zone.
[0020] Figure 2 The utility model is a schematic diagram of the connection structure between the drain pipe, the water retaining plate and the water collection well.
[0021] Figure 3 It is a structural schematic diagram of the second drain pipe according to the utility model.
[0022] Figure 4 It is a structural schematic diagram of a top cover provided on the second drain pipe according to the utility model.
[0023] Figure 5 According to the utility model Figure 4 Schematic diagram of the top view structure.
[0024] Description of main reference numerals:
[0025] 1-secondary lining, 2-blind ditch, 3-primary lining, 4-first drainage pipe, 5-water collection well, 6-second drainage pipe, 7-inverted arch primary lining, 8-inverted arch secondary lining, 9-central drainage ditch, 10-graded gravel, 11-second drainage pipe, 12-water retaining plate, 13-first drainage pipe, 14-side drainage ditch, 15-expansion water stop ring, 16-iron sand mesh, 17-filter material, 18-filter chamber, 19-water inlet hole, 20-drainage hole, 21-top cover. DETAILED DESCRIPTION
[0026] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation modes.
[0027] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.
[0028] Figures 1 to 5 A structural schematic diagram of a drainage structure for a single-hole double-track tunnel crossing a water-rich fault fracture zone according to a preferred embodiment of the utility model is shown, wherein the drainage structure includes a blind ditch 2, a side drainage ditch 14, a first drainage pipe 4, a central drainage ditch 9, a second drainage pipe 6, a first drainage pipe 13, a second drainage pipe 11 and a water collection well 5.
[0029] refer to Figures 1 to 5, multiple blind ditches 2 are distributed at intervals along the length direction of the tunnel, each blind ditch 2 is in an arch shape corresponding to the tunnel contour line, and each blind ditch 2 is located between the primary lining 3 and the surrounding rock to drain the surrounding rock of the tunnel. The blind ditch 2 is used for drainage. The drainage channel composed of the blind ditch 2 material can not only effectively remove moisture and prevent water accumulation inside the tunnel, but also act as a buffer layer to give play to the self-bearing role of the surrounding rock, so that the tunnel can be more stable and durable when subjected to external pressure. A side drainage ditch 14 is provided on each side of the bottom surface of the tunnel. The length of each side drainage ditch 14 is distributed along the length direction of the tunnel, and each side drainage ditch 14 is located on the inner side of the secondary lining 1. The two ends of each blind ditch 2 are connected to the corresponding side drainage ditch 14 through a first drainage pipe 4, so that the moisture in the blind ditch 2 is discharged into the side drainage ditch 14 through the first drainage pipe 4. The central drainage ditch 9 is arranged on the bottom surface of the tunnel and located on the center line of the tunnel. The length of the central drainage ditch 9 is distributed along the length direction of the tunnel. Each side drainage ditch 14 is connected to the central drainage ditch 9 through the second drainage pipe 6, so that the water in the side drainage ditch 14 is discharged into the central drainage ditch 9 through the second drainage pipe 6, thereby connecting the blind ditch 2, the side drainage ditch 14 and the central drainage ditch 9 into a whole, thereby improving the drainage effect. Each side drainage ditch 14 is provided with a plurality of first drainage pipes 13 distributed at intervals along its length direction, and the upper end of each first drainage pipe 13 is connected to the corresponding side drainage ditch 14, and the upper end opening of the first drainage pipe 13 is located in the middle and upper part of the corresponding side drainage ditch 14, so as to prevent the water in the side drainage ditch 14 from flowing into the water collection well 5 below through the first drainage pipe 13. Among them, the upper end opening of the first drainage pipe 13 is preferably located above the outlet of the first drainage pipe 4 and above the inlet of the second drainage pipe 6. The central drainage ditch 9 is provided with a plurality of second drainage pipes 11 distributed at intervals along its length direction, and the upper end of each second drainage pipe 11 is connected to the central drainage ditch 9. The upper opening of the second drainage pipe 11 is located in the middle and upper part of the central drainage ditch 9 to prevent the water in the central drainage ditch 9 from flowing into the water collection well 5 below through the first drainage pipe 13. The upper opening of the second drainage pipe 11 is preferably located above the outlet of the second drainage pipe 6. A filtering device is provided at the upper end of the second drainage pipe 11. On the one hand, it can filter fine sand and gravel in the water to prevent the central drainage ditch 9 from being blocked after long-term use and ensure the drainage effect; on the other hand, it can also reduce the impact of water and alleviate the impact of the scouring effect on the central drainage ditch 9. Since the side drainage ditch 14 is easy to clean, the filtering device may not be provided on the top of the first drainage pipe 13. The surrounding rock at the bottom of the tunnel is provided with a water collection well 5 at the position corresponding to each first drainage pipe 13 and at the position corresponding to each second drainage pipe 11. The lower end of each first drainage pipe 13 and the lower end of each second drainage pipe 11 successively penetrate the secondary lining 8 and the primary lining 7 of the inverted arch downward and extend downward into the corresponding water collection well 5.After the groundwater in the surrounding rock at the bottom of the tunnel flows into the water collection well 5, it will be discharged upward by the drainage pipe into the corresponding drainage ditch to achieve the purpose of draining the groundwater, thereby achieving the purpose of combined drainage of the tunnel circumferentially and the surrounding rock at the bottom of the tunnel, which is particularly suitable for areas with high water levels in water-rich areas, and can improve the drainage effect and drainage efficiency. The structure of the water collection well 5, the first drainage pipe 13 and the two side drainage ditches 14 connected, combined with the structure of the water collection well 5, the second drainage pipe 11 and the central drainage ditch 9 connected, can further improve the drainage efficiency and effect of the surrounding rock at the bottom of the tunnel, avoid damage to the tunnel invert, achieve full drainage of the tunnel circumferentially, and reduce water erosion of the tunnel structure.
[0030] refer to Figures 3 to 5 Preferably, the filtering device includes a filter chamber 18 and a top cover 21. The top of the second drain pipe 11 is provided with a filter chamber 18. The diameter of the filter chamber 18 is larger than the outer diameter of the second drain pipe 11, that is, the upper end of the second drain pipe 11 is in a T shape. A filter screen is provided between the filter chamber 18 and the upper end opening of the second drain pipe 11. The top of the filter chamber 18 is open, and a top cover 21 that can be opened and closed is provided at the top opening of the filter chamber 18. The top cover 21 is threadedly connected to the filter chamber 18; a plurality of drainage holes 20 are provided on the top cover 21. Among them, the filter chamber 18 is filled with a filter material 17 for filtering impurities in the water in the second drain pipe. When impurities block the filter material 17 and the filter screen, open the top cover 21, clean the filter screen and replace the filter material 17. The cleaning method is simple and convenient.
[0031] refer to Figure 1 Preferably, a middle partition wall is provided on the center line of the tunnel, and a reserved channel is provided on the middle partition wall at a position corresponding to each second drainage pipe 11, and an openable and closable top plate is provided on the top of the central drainage ditch 9 at a position corresponding to each second drainage pipe 11, so as to facilitate replacement and cleaning of the filtering device and ensure the drainage filtering buffer effect of the second drainage pipe 11.
[0032] refer to Figures 1 to 5 The lower end of the first drain pipe 13 and the lower end of the second drain pipe 11 can be an opening, or a structure in which an opening is combined with a water inlet hole 19 on the side wall for drainage. In order to improve the drainage effect, preferably, a plurality of water inlet holes 19 distributed in a plum blossom shape and connected to the corresponding water collection well 5 are provided on the lower end side wall of the first drain pipe 13; a plurality of water inlet holes 19 distributed in a plum blossom shape and connected to the corresponding water collection well 5 are provided on the lower end side wall of the second drain pipe 11 to improve the drainage effect. In order to prevent impurities from clogging the drain pipe and the drainage ditch, it is further preferred that the lower end opening of the first drain pipe 13 and the water inlet hole 19 on the side wall are wrapped with an iron sand mesh 16, and the lower end opening of the second drain pipe 11 and the water inlet hole 19 on the side wall are also wrapped with an iron sand mesh 16 to prevent sand and gravel from clogging the drainage hole, drain pipe and filter device, thereby ensuring the drainage effect.
[0033] refer to Figure 1 and Figure 2 Preferably, the water collection well 5 is backfilled with graded gravel 10 to filter the coarse sand and slow down the flow, thereby performing primary filtration on the groundwater and preventing impurities from clogging the drainage pipe and the filtering device.
[0034] refer to Figure 1 and Figure 2 Preferably, the drainage structure also includes a water retaining plate 12. A water retaining plate 12 is provided between the surrounding rock at the bottom of the tunnel and the primary lining 7 of the inverted arch. The lower end of each first drainage pipe 13 and the lower end of each second drainage pipe 11 successively penetrate downward through the secondary lining 8 of the inverted arch, the primary lining 7 of the inverted arch and the water retaining plate 12 and extend downward into the corresponding water collection well 5. The water retaining plate 12 can separate the surrounding rock at the bottom of the tunnel from the primary lining 7 of the inverted arch, thereby reducing the impact of groundwater on the tunnel structure. In order to prevent groundwater from flowing into the space between the water retaining plate 12 and the primary lining 7 of the inverted arch, it is further preferred that an expansion water stop ring 15 is provided between each first drainage pipe 13 and the water retaining plate 12, and between each second drainage pipe 11 and the water retaining plate 12, so as to seal the gap between the drainage pipe and the water retaining plate 12.
[0035] refer to Figure 1 In order to prevent the impurities in the side drain ditch 14 from flowing into the central drain ditch 9, a filter net may be provided at one end where the second drain pipe 6 is connected to the side drain ditch 14; or the inlet of the second drain pipe 6 connected to the side drain ditch 14 may be provided at the middle of the side wall of the side drain ditch 14. Preferably, the inlet of the first drain pipe 4 is connected to the middle of the side wall of the corresponding side drain ditch 14, and the impurities in the side drain ditch 14 are deposited at the bottom of the side drain ditch 14. The structure in which the inlet of the first drain pipe 4 is provided at the middle of the side wall of the side drain ditch 14 can prevent the impurities from flowing into the central drain ditch 9, thereby preventing the central drain ditch 9 from being blocked. The impurities deposited at the bottom of the side drain ditch 14 are easy to clean because the cover plate at the top of the side drain ditch 14 can be opened.
[0036] refer to Figure 1 Preferably, plastic film and iron window screen are arranged between the blind ditch 2 and the primary lining 3 from outside to inside. The plastic film can prevent moisture from penetrating into the primary lining 7 of the invert, and the structure of the iron sand mesh 16 can play a role in fixing the slurry during the initial spraying of concrete.
[0037] By adopting the drainage structure of the utility model, it is possible to combine drainage of the tunnel circumferentially and the surrounding rock at the bottom of the tunnel, thereby achieving full drainage of the tunnel circumferentially and reducing water erosion of the tunnel structure; a filtering device is provided at the upper end of the second drain pipe 11, which can filter out fine sand and gravel in the water on the one hand to avoid clogging of the central drainage ditch 9 after long-term use, thereby ensuring the drainage effect; on the other hand, it can also reduce the impact force of water and alleviate the influence of scouring on the central drainage ditch 9.
[0038] The foregoing description of specific exemplary embodiments of the utility model is for the purpose of illustration and illustration. These descriptions are not intended to limit the utility model to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the utility model and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the utility model and various different options and changes. The scope of the utility model is intended to be defined by the claims and their equivalents.
Claims
1. A drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone, characterized in that: include: Blind trenches, a plurality of which are spaced apart along the length of the tunnel, each of which is in an arch shape corresponding to the tunnel contour, and each of which is located between the primary lining and the surrounding rock; Side drainage ditches, each of which is provided on both sides of the tunnel bottom surface, the length of each side drainage ditch is distributed along the length direction of the tunnel, and each side drainage ditch is located on the inner side of the secondary lining; A first drainage pipe, wherein both ends of each blind ditch are connected to the corresponding side drainage ditch through a first drainage pipe; A central drainage ditch is arranged on the bottom surface of the tunnel and located on the center line of the tunnel, and the length of the central drainage ditch is distributed along the length direction of the tunnel; A second drain pipe, each of the side drains is connected to the central drain through the second drain pipe; A first drain pipe, each of the side drain ditch is provided with a plurality of the first drain pipes distributed at intervals along the length direction thereof, the upper end of each of the first drain pipes is communicated with the corresponding side drain ditch, and the upper end opening of the first drain pipe is located at the middle and upper part of the corresponding side drain ditch; A second drainage pipe, wherein the central drainage ditch is provided with a plurality of second drainage pipes distributed at intervals along its length direction, and the upper end of each second drainage pipe is connected to the central drainage ditch; wherein the upper end opening of the second drainage pipe is located in the middle and upper part of the central drainage ditch, and a filtering device is provided at the upper end of the second drainage pipe; and A water collection well is provided in the surrounding rock at the bottom of the tunnel at a position corresponding to each of the first drainage pipes and at a position corresponding to each of the second drainage pipes. The lower end of each of the first drainage pipes and the lower end of each of the second drainage pipes successively penetrate the secondary lining of the invert and the primary lining of the invert and extend downward into the corresponding water collection well.
2. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 1 is characterized in that: The filtering device comprises a filter chamber and a top cover. The filter chamber is provided at the top of the second drain pipe. The diameter of the filter chamber is larger than the outer diameter of the second drain pipe, and a filter net is provided between the filter chamber and the upper end opening of the second drain pipe. The top of the filter chamber is open, and the top opening of the filter chamber is provided with the openable and closable top cover, and the top cover is provided with a plurality of drain holes distributed at intervals. The filter chamber is filled with filtering material.
3. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 1 or 2, characterized in that: A middle partition wall is provided on the center line of the tunnel, and a reserved channel is provided on the middle partition wall at a position corresponding to each of the second drainage pipes, and an openable and closable top plate is provided on the top of the central drainage ditch at a position corresponding to each of the second drainage pipes.
4. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 1, characterized in that: The lower end side wall of the first drain pipe is provided with a plurality of water inlet holes distributed in a plum blossom shape and connected to the corresponding water collection well; the lower end side wall of the second drain pipe is provided with a plurality of water inlet holes distributed in a plum blossom shape and connected to the corresponding water collection well.
5. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 4 is characterized in that: The lower end opening and the side wall water inlet hole of the first drain pipe are both wrapped with iron sand mesh, and the lower end opening and the side wall water inlet hole of the second drain pipe are also wrapped with iron sand mesh.
6. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 1 or 5, characterized in that: The water collection well is backfilled with graded crushed stones.
7. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 1, characterized in that: It also includes a water retaining plate, which is arranged between the surrounding rock at the bottom of the tunnel and the primary lining of the invert arch. The lower end of each of the first drainage pipes and the lower end of each of the second drainage pipes successively penetrate downward through the secondary lining of the invert arch, the primary lining of the invert arch and the water retaining plate and extend downward into the corresponding water collection well.
8. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 7, characterized in that: An expansion water stop ring is provided between each of the first drain pipes and the water baffle plate, and between each of the second drain pipes and the water baffle plate.
9. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 1, characterized in that: The inlet of the first drain pipe is connected to the middle portion of the side wall of the corresponding side drain ditch.
10. The drainage structure for a single-hole double-line tunnel passing through a water-rich fault zone according to claim 1, characterized in that: A plastic film and an iron window screen are arranged in sequence from outside to inside between the blind ditch and the primary lining.