Tunnel portal drainage device and drainage method

Abstract

This invention relates to the field of tunnel engineering drainage technology, and discloses a tunnel entrance drainage device and method, including a water collection component, a diversion and storage component, a drainage energy dissipation component, an ecological irrigation component, an open-cut channel, and a portal wall. The open-cut channel is arranged along the tunnel axial direction; the water collection component is arranged on the open-cut channel; the portal wall is arranged along the tunnel axial direction and embedded in the mountain, and the portal wall has several end wall notches; the drainage energy dissipation component is arranged along the tunnel axial direction and includes an energy dissipation staircase and an energy dissipation pool; the diversion and storage component includes a water collection and diversion device and a water storage device, one end of the water collection and diversion device is connected to the energy dissipation pool, and the other end of the water collection and diversion device is connected to the water storage device; the ecological irrigation component is connected to the water storage device so that water in the water storage device enters the ecological irrigation component to irrigate the slope vegetation layer.

Description

Technical Field

[0001] This invention relates to the field of drainage technology in tunnel engineering, and in particular to a drainage device and method for tunnel entrances. Background Technology

[0002] Mountain tunnel projects often face the threat of flash flood erosion at the tunnel entrance. After heavy rain, the mountain slopes are rapidly flooded, forming sudden floods. If the drainage capacity is insufficient, the flood can easily backflow into the tunnel or erode the tunnel entrance structure, seriously affecting the operational safety of the tunnel project.

[0003] Currently, tunnel entrance drainage designs mostly adopt ring-shaped intercepting ditches or partial diversion schemes. However, ring-shaped intercepting ditches have limited interception capacity and are difficult to cope with large-scale flash floods. Large-scale diversion projects have problems such as large engineering volume, high cost, and significant disturbance to the topography. Moreover, drainage designs focus solely on rapid outflow, neglecting the potential value of rainwater resources. Ecological protection of slopes around tunnel entrances, such as hydroseeding and vegetation bags, often suffer from vegetation degradation and exposed slopes due to water shortages during the dry season or prolonged periods of low rainfall, which exacerbates the risk of soil erosion. The drainage system and the slope ecological maintenance system are independent of each other and fail to form a synergistic effect. Summary of the Invention

[0004] To overcome at least one of the defects described in the prior art, the present invention provides a tunnel entrance drainage device and drainage method that can effectively intercept and dissipate mountain torrents, ensuring the safe operation of the tunnel; it can also recycle rainwater resources, solve the problem of water shortage for slope vegetation during the dry season, and inhibit soil erosion; it does not require large-scale ditch modification, reducing engineering work and costs, and taking into account safety, economy and ecology.

[0005] In a first aspect, this application provides a tunnel portal drainage device, including a water collection component, a diversion and storage component, a drainage and energy dissipation component, an ecological irrigation component, an open-cut channel, and a portal wall, wherein... The open-cut channel is set along the axial direction of the tunnel; The water collection component is disposed on the open channel, and the water collection component includes a plurality of water collection pits; The portal wall is set along the tunnel axis and embedded in the mountain, and is arranged in sequence with the open tunnel. Several end wall notches are opened on the portal wall, and the end wall notches are set one-to-one with the water collection pit. The drainage energy dissipation component is arranged along the tunnel axial direction. The drainage energy dissipation component includes an energy dissipation staircase and an energy dissipation pool. The water inlet end of the energy dissipation staircase is connected to the end wall gap, and the water outlet end of the energy dissipation staircase is connected to the water inlet end of the energy dissipation pool. The diversion and storage component includes a water collection and diversion device and a water storage device. One end of the water collection and diversion device is connected to the energy dissipation tank, and the other end of the water collection and diversion device is connected to the water storage device. The ecological irrigation component is connected to the water storage device so that water from the water storage device enters the ecological irrigation component to irrigate the slope vegetation layer.

[0006] In one embodiment, the open channel includes a first open channel, a second open channel, and an ecological infiltration layer, wherein, The first open-cut channel is made of sand-free large-pore concrete. Several water collection pits are arranged linearly along the first open-cut channel. A core-extractable permeable pipe is installed in the first open-cut channel. The core-extractable permeable pipe passes through the portal wall and extends to the outside of the tunnel so that the seepage water can be discharged out of the tunnel through the core-extractable permeable pipe. The second open-cut channel is arranged sequentially with the first open-cut channel. The second open-cut channel is located on the side of the first open-cut channel away from the portal wall. A water-sealing layer is provided on the second open-cut channel. The water-sealing layer is made of rock and soil material and is used to reduce surface water leakage. The ecological infiltration layer is set on the ground surface around the outer perimeter of the first open tunnel, and the bottom surface of the ecological infiltration layer is connected to the sand-free large-pore concrete.

[0007] In one embodiment, the ecological infiltration layer includes a greening layer, a permeable substrate layer, and a drainage layer, wherein, The drainage layer is connected to the sand-free large-pore concrete, and the drainage layer is used to collect the infiltrated water after being filtered by the permeable matrix layer. The permeable matrix layer is disposed on the top surface of the drainage layer; The greening layer is set on the top surface of the permeable substrate layer.

[0008] In one embodiment, the interior of the portal wall is provided with integral reinforcement, which includes a plurality of equally spaced steel bars, and the bottom of the portal wall is provided with a micropile foundation.

[0009] In one embodiment, the drainage energy dissipation assembly further includes a buttress wall, a water-retaining plate, and a handrail, wherein, The buttress walls are located on both sides of the energy-dissipating staircase; The handrail is located at the top of the buttress wall; The water baffle is installed on both sides of the energy dissipation staircase, and the height of the water baffle is higher than the height of the buttress wall. The water baffle is located on the outside of the buttress wall and is used to adjust the height of the water flow section inside the energy dissipation staircase.

[0010] In one embodiment, the water collection and diversion device includes a valve assembly, a channel assembly, and a filter and sedimentation assembly, wherein, The channel assembly includes a connecting channel and an outlet channel. One end of the connecting channel is connected to the energy dissipation pool and the other end is connected to the water storage device. One end of the outlet channel is connected to the energy dissipation pool and the other end is connected to the external drainage system of the tunnel. The valve assembly includes a first diversion valve and a second diversion valve. The first diversion valve is disposed on the connection channel and is used to control the opening or closing of the connection channel. The second diversion valve is disposed on the outlet channel and is used to control the opening or closing of the outlet channel. The filter and sedimentation assembly is disposed on the connection channel and is used to filter impurities flowing to the water storage device.

[0011] In one embodiment, the filtration and sedimentation assembly includes a coarse filter layer, a fine filter layer, a water collection layer, and a stainless steel filter screen. The coarse filter layer, the fine filter layer, and the water collection layer are sequentially arranged within the connecting channel. The coarse filter layer is used to intercept large-diameter suspended solids and retain silt and sand, and the coarse filter layer is filled with volcanic rock. The fine filter layer is used to adsorb fine particulate matter, and the fine filter layer is filled with maifan stone filter media. The water collection layer is used to collect filtered water and is made of quartz sand. The stainless steel filter screen is disposed within the connecting channel, and is disposed between the coarse filter layer and the fine filter layer, and between the fine filter layer and the water collection layer.

[0012] In one embodiment, the ecological irrigation component includes a main irrigation pipe and a drip irrigation pipe, wherein, The irrigation main pipe is connected to the outlet of the water storage device, and an anti-backflow device is provided between the irrigation main pipe and the water storage device; The drip irrigation pipe is connected to the main irrigation pipe and is laid in the vegetation layer of the slope. The drip irrigation pipe has multiple evenly distributed water outlet holes.

[0013] In one embodiment, the top of the energy dissipation pool is provided with an opening, and the opening is provided with an openable cover.

[0014] Secondly, this application provides a tunnel entrance drainage method, applied to the aforementioned tunnel entrance drainage device, comprising the following steps: S1: Collects floodwater through a drainage pit; S2: Real-time monitoring of water flow and water level in the collection pit, comparing the monitored water flow with the preset water flow threshold, and comparing the water level in the collection pit with the preset water level threshold; S3: When the monitored water flow is less than the water flow threshold or the water level in the water collection pit is less than the water level threshold, the floodwater seeps into the sand-free large-pore concrete through the ecological infiltration layer, and then is led out of the tunnel through the core-extractable permeable pipe to achieve ecological absorption and underground drainage. S4: When the monitored water flow exceeds the water flow threshold or the water level in the water collection pit exceeds the water level threshold, the floodwaters are collected in the water collection pit through the open tunnel channel, and then enter the energy dissipation staircase. The water flow dissipates energy step by step along the energy dissipation staircase and then flows into the energy dissipation pool. Finally, the floodwaters are discharged into the drainage system outside the tunnel through the outlet ditch. At the same time, the floodwaters seep into the sand-free large-pore concrete through the ecological infiltration layer and are then led out of the tunnel through the core-extractable permeable pipe, realizing ecological absorption and underground infiltration and drainage. S5: When the flood water quality meets the irrigation requirements and the water storage equipment is not full, open the first diversion valve to allow some floodwater to enter the water storage equipment; when the flood water quality does not meet the requirements or the water storage equipment is full, close the first diversion valve and open the second diversion valve to allow the floodwater to be discharged through the outlet ditch to the drainage system outside the tunnel. S6: Water seepage irrigation is implemented on the slope vegetation layer through the main irrigation pipe and seepage pipe to achieve the recycling of flood resources. In summary, the tunnel entrance drainage device and method provided by this invention have the following advantages over existing technologies:

[0015] (1) By combining the water collection pit with the open tunnel channel, the flood can be quickly collected, avoiding the disorderly scouring of the tunnel entrance by the slope confluence; the energy dissipation steps and energy dissipation pool of the drainage energy dissipation components can dissipate the energy of the mountain torrent step by step, reduce the scouring force of the water flow, prevent the water flow from damaging the tunnel entrance structure, and avoid the problem of insufficient energy dissipation; the diversion and storage components can realize the diversion and storage of floods, providing a basis for the recycling of flood resources; and the ecological irrigation components are combined with the irrigation of slope vegetation, solving the problem of water shortage and degradation of slope vegetation in the dry season and the exposure of the slope surface; the whole does not require large-scale ditch modification, the amount of engineering is small, the disturbance to the topography is small, and the economy and environmental protection are taken into account, effectively ensuring the safety of tunnel operation; (2) The first open-cut trench uses sand-free, large-pore concrete with a core-extractable permeable pipe to achieve rapid drainage of seepage water, avoid the accumulation of seepage water and damage to the tunnel structure, and facilitate later maintenance; the second open-cut trench is equipped with a water-sealing layer to effectively reduce surface water leakage, reduce the risk of seepage inside the tunnel, and ensure the stability of the tunnel structure; the ecological infiltration layer is connected to the first open-cut trench to achieve surface water infiltration and purification, reduce surface runoff pressure, replenish groundwater, and provide a certain amount of water for slope vegetation, further enhancing the ecological maintenance effect; the combination of sand-free, large-pore concrete and core-extractable permeable pipe improves the efficiency and reliability of seepage water drainage; (3) The rainwater is transported to the water storage equipment and discharged to the drainage system outside the tunnel through the connecting channel and the outlet ditch of the water collection and diversion device, forming a two-way diversion path; the first diversion valve and the second diversion valve can be flexibly switched according to the actual situation to achieve precise control of water storage and discharge, and avoid the overflow of water storage equipment or waste of water resources; the filter and sedimentation component filters the floodwater flowing to the water storage equipment, removes impurities, prevents the water storage equipment from being blocked, ensures the water quality of the stored water, provides water source for subsequent ecological irrigation, and extends the service life of the water storage equipment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic plan view of the tunnel entrance of a tunnel entrance drainage device according to an embodiment of this application; Figure 2 This is a schematic diagram of the tunnel entrance elevation of a tunnel entrance drainage device according to an embodiment of this application; Figure 3 This is a side view of the tunnel entrance of a tunnel entrance drainage device according to an embodiment of this application; Figure 4 This is a schematic plan view of the tunnel portal wall of a tunnel entrance drainage device according to an embodiment of this application; Figure 5 This is a schematic diagram showing the connection between the ecological irrigation components and the energy dissipation pool of a tunnel entrance drainage device according to an embodiment of this application; The meanings of the reference numerals in the attached diagrams are as follows: 1. Sump; 2. First open-cut channel; 3. Second open-cut channel; 4. Ecological infiltration layer; 5. Outlet; 6. Platform retaining wall; 7. Buttress wall; 8. Energy dissipation staircase; 9. Energy dissipation pool; 10. First diversion valve; 11. Outlet ditch; 12. Portal wall; 13. Cut slope; 14. Debris dumping platform; 15. Road surface; 16. Tunnel; 17. Mountain; 18. Ditch behind the wall; 9. End wall notch; 20. Cover plate; 21. Core-extractable permeable pipe; 22. Sand-free large-pore concrete; 23. Green layer; 24. Water sealing layer; 25. Water retaining plate; 26. Overall reinforcement; 27. Micropile foundation; 28. Open channel trench; 29. ​​Water collection and diversion device; 30. Second diversion valve; 31. Connecting channel; 32. Filter and sedimentation assembly; 33. Water storage equipment; 34. Irrigation main pipe; 35. Drip irrigation pipe. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0020] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention 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. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0021] Furthermore, the terms "first" and "second" are used 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 as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0024] In one embodiment, see Figures 1-5 As shown, the present invention discloses a drainage device for the entrance of tunnel 16, including a water collection component, a diversion and storage component, a drainage and energy dissipation component, an ecological irrigation component, a tunnel channel 28, and a tunnel entrance wall 12.

[0025] Specifically, the open channel 28 is set along the axial direction of the tunnel 16. The open channel 28 is a trough-shaped structure formed by excavation of the tunnel 16 entrance section. It is located in front of the tunnel entrance wall 12, i.e., outside the tunnel 16. The open channel 28 is consistent with the terrain of the tunnel 16 entrance and the slope of the mountain 17, making the most of the natural terrain for flood collection and reducing the disturbance to the original terrain. The flood collects along the axial direction of the tunnel 16 to the open channel 28, which is consistent with the axial direction of the tunnel 16. The water flow path is the shortest and the resistance is the least, avoiding the formation of eddies or overflows in the tunnel entrance area.

[0026] In some embodiments, the open-cut channel 28 includes a first open-cut channel 2, a second open-cut channel 3, and an ecological infiltration layer 4. The first open-cut channel 2 is made of sand-free large-pore concrete 22, which has good permeability and can collect seepage water from the mountain 17 for a long time, reducing the earth pressure acting on the tunnel 16. The second open-cut channel 3 is arranged sequentially with the first open-cut channel 2, and is located behind the first open-cut channel 2, i.e., on the side of the first open-cut channel 2 away from the tunnel entrance wall 12. A water-sealing layer 24 is provided on the second open-cut channel 3. The water-sealing layer 24 is made of rock and soil material and is used to reduce surface water seepage. The rock and soil material is made of concrete or clay and fills the second open-cut channel 3 to prevent surface water infiltration and reduce the impact on the tunnel 16 structure. The static water pressure of the structure; the ecological infiltration layer 4 is set on the surface of the outer periphery of the first open channel 2. The bottom surface of the ecological infiltration layer 4 is connected to the sand-free large-pore concrete 22. This design of the ecological infiltration layer 4 just covers the necessary path of flood from the road cut slope 13 to the open channel 28, which can intercept and absorb the slope runoff to the maximum extent and avoid the flood directly scouring the open channel 28. The surface of the outer periphery of the first open channel 2 is usually the transition area between the mountain slope 17 and the open channel 28. The ecological infiltration layer 4 is set here to conform to the topographic elevation difference, so that the flood flows into the ecological infiltration layer 4 naturally under the action of gravity without additional energy consumption, and does not occupy the internal space of the open channel 28, ensuring that the open channel 28 has enough space to collect floods and realize the functions of peripheral absorption and core confluence. Specifically, the water collection component is installed on the open channel 28. The water collection component includes several water collection pits 1, which are arranged linearly along the first open channel 2. There are three water collection pits 1, located in the middle and on both sides of the first open channel 2, respectively. A wall-backed ditch 18 is provided between two adjacent water collection pits 1, which can effectively collect floods from different directions in the open channel 28 and then fall into the water collection pits 1 after being collected by the wall-backed ditch 18, thus avoiding the disorderly flow of floods in the open channel 28 or direct impact on the portal wall 12.

[0027] Specifically, the ecological infiltration layer 4 includes a greening layer 23, a permeable matrix layer, and a drainage layer. The ecological infiltration layer 4 is used to preferentially absorb and purify small-flow floodwater and seepage. The drainage layer is connected to the sand-free, large-pore concrete 22 and is used to collect infiltrated water filtered by the permeable matrix layer. The permeable matrix layer is located on the top surface of the drainage layer. The greening layer 23 is located on the top surface of the permeable matrix layer. The greening layer 23 is the surface layer, planted with vegetation. Through the interception of vegetation branches and leaves and the soil stabilization by roots, the surface runoff pattern is slowed down. It forms and prevents soil erosion on slopes; the permeable matrix layer uses improved soil and functional fillers to physically intercept, chemically adsorb and biodegrade infiltrated floodwater, achieving water purification and temporary storage; the drainage layer quickly collects the purified water and evenly guides it to the 22 layers of sand-free large-pore concrete, forming a continuous treatment of surface interception, permeable matrix layer purification, drainage layer guidance and underground infiltration; it enables small-scale floods and seepage water to be preferentially absorbed through ecological pathways, which not only reduces the burden on the engineering drainage system, but also improves the quality of effluent water through ecological filtration.

[0028] In some embodiments, the portal wall 12 is arranged along the axial direction of the tunnel 16 and embedded in the mountain 17. The two sides of the portal wall 12 are embedded within the stable mountain 17, forming an integral load-bearing structure with the mountain 17, effectively resisting the enormous earth and water pressure during flood discharge. The portal wall 12 and the open-cut channel 28 are arranged sequentially, ensuring a tight connection between the portal wall 12 and the open-cut channel 28. Several end wall notches 19 are provided on the portal wall 12, each corresponding to a water collection pit 1. Since there are three water collection pits 1, then... There are also three end wall gaps 19, which are located in the middle and on both sides of the portal wall 12. The end wall gaps 19 are set up one-to-one with the water collection pits 1, so that the floodwater collected in the open channel 28 can directly and orderly enter the back of the portal wall 12 through the end wall gaps 19, avoiding the floodwater from stagnating, overflowing or impacting the wall in the portal wall 12. The corresponding layout of multiple water collection pits 1 and multiple end wall gaps 19 forms a multi-point diversion drainage pattern, which can evenly distribute the flood discharge channel according to the water volume of different areas, thereby improving drainage efficiency.

[0029] Multiple overflow outlets are provided at each water collection pit 1 or end wall opening. This design allows mountain floods from different directions to converge in the open tunnel 28 area and then enter the drainage and energy dissipation components behind the tunnel portal wall 12 through the end wall opening.

[0030] It should also be noted that a core-extraction permeable pipe 21 is installed inside the first open-cut trench 2, i.e., the sand-free large-pore concrete 22. The core-extraction permeable pipe 21 passes through the portal wall 12 and extends to the outside of the tunnel 16, so that seepage water can be discharged outside the tunnel 16 through the core-extraction permeable pipe 21. As a highly permeable medium, the sand-free large-pore concrete 22 can collect seepage water from the mountain 17 and floodwater infiltrating through the ecological infiltration layer 4 for a long time, forming a stable underground seepage field, effectively reducing the impact on the portal wall 12 and the tunnel. The water pressure on the structure of tunnel 16 is controlled by the core-extractable permeable pipe 21, which penetrates into the sand-free large-pore concrete 22. Gravity is used to orderly guide the collected underground seepage water out of tunnel 16, avoiding the adverse effects on the structure caused by the accumulation of seepage water at the bottom of the open tunnel trough 28. Some floodwater flows into the rock and soil around tunnel 16 through the mountain 17 and part of the water-sealing layer 24. After seeping into the sand-free large-pore concrete 22 behind the portal wall 12, it is collected and then drained out of tunnel 16 by the core-extractable permeable pipe 21.

[0031] The portal wall 12 is internally reinforced with integral reinforcement 26, which includes several equally spaced steel bars. The integral reinforcement 26 enhances the overall structural strength and crack resistance of the portal wall 12. When the soil pressure and water pressure behind the wall act together during flood discharge, the steel bars bear the tensile stress, effectively preventing the wall from cracking under bending moment. The bottom of the portal wall 12 is provided with micropile foundation 27, which effectively avoids the adverse effects of uneven settlement on the portal wall 12.

[0032] In some embodiments, the drainage energy dissipation assembly is arranged along the axial direction of the tunnel 16. The drainage energy dissipation assembly includes an energy dissipation staircase 8 and an energy dissipation pool 9. The water inlet end of the energy dissipation staircase 8 is connected to the end wall gap 19, and the water outlet end of the energy dissipation staircase 8 is connected to the water inlet end of the energy dissipation pool 9. The energy dissipation staircase 8 is directly connected to the end wall gap 19, so that the flood overflowing from the collection pit 1 directly enters the energy dissipation system of the energy dissipation staircase 8, avoiding the disorderly scouring of the flood at the portal wall 12. The energy dissipation staircase 8 is arranged along the axial direction of the tunnel 16, and the energy dissipation staircase 8 is in a stepped shape. The staircase descends in sequence, using its stepped structure to allow the high-speed floodwater to fall step by step along the staircase. Through water jumps and water flow impacts, the kinetic energy is gradually dissipated, significantly reducing the water flow velocity and the impact force on downstream structures. After the initial energy dissipation by the energy dissipation staircase 8, the floodwater flows into the energy dissipation pool 9 for secondary energy dissipation and buffering. At the same time, the energy dissipation staircase 8 does not occupy additional space, and the staircase itself also serves as a maintenance passage. It can be used as a passage for maintenance personnel to enter the entrance of tunnel 16 for inspection and maintenance, realizing the functions of drainage energy dissipation and maintenance passage.

[0033] It should also be noted that since there are three end wall gaps 19 and three water collection pits 1, there are also three energy dissipation stairs 8. Moreover, the three energy dissipation stairs 8 are set one-to-one with the three end wall gaps 19 to ensure that the floodwater at each end wall gap 19 is received by the energy dissipation stairs 8 in a timely manner.

[0034] It should also be noted that platform retaining walls 6 are installed at the energy dissipation stairs 8 on both sides to provide lateral restraint to the backfill soil and ensure the stability of the backfill platform during operation. At the same time, the platform retaining walls 6 physically isolate the backfill soil from the energy dissipation stairs 8 on both sides to prevent the backfill soil from flowing into the energy dissipation stairs 8 area and ensure that the drainage channels of the energy dissipation stairs 8 are unobstructed.

[0035] The energy dissipation pool 9 has an opening at the top, and an openable cover 20 is provided at the opening. The cover 20 can expose the interior of the energy dissipation pool 9, making it easy to clean and maintain the interior.

[0036] The drainage energy dissipation components also include buttress walls 7, water-retaining plates 25, and handrails. The buttress walls 7 are located on both sides of each energy dissipation staircase 8. The handrails are located on the top of each buttress wall 7. The handrails provide safe and reliable passage assistance for maintenance personnel, meeting the pedestrian needs for maintenance and dredging during operation. The water-retaining plates 25 are located on both sides of the energy dissipation staircase 8, with a height higher than the buttress walls 7 and situated on the outer side of the buttress walls 7. The water-retaining plates 25 are used to adjust the height of the water flow section within the energy dissipation staircase 8. Their location on both sides of the energy dissipation staircase 8 and on the outer side of the buttress walls 7, with a height higher than the buttress walls 7, creates a controllable water-retaining boundary on both sides of the staircase, achieving a dynamic balance between energy dissipation effect and flood discharge capacity.

[0037] It should also be noted that a road surface 15 is laid at the entrance of tunnel 16. A debris platform 14 is set on one side of the road surface 15, and a road cutting slope 13 is set on one side of the debris platform 14. The debris platform 14 is set between the road surface 15 and the road cutting slope 13 to form a physical isolation zone. When local rockfalls, soil debris or small landslides occur on the road cutting slope 13, the debris platform 14 can intercept and buffer the falling objects to prevent them from rolling directly onto the road surface 15 and affecting traffic safety, thereby reducing the direct threat of slope geological disasters to the operational safety of tunnel 16.

[0038] In some embodiments, the diversion and storage component includes a water collection and diversion device 29 and a water storage device 33. One end of the water collection and diversion device 29 is connected to the energy dissipation pool 9, and the other end of the water collection and diversion device 29 is connected to the water storage device 33. Through the water collection and diversion device 29, a channel for drainage, diversion, and storage is constructed, so that the floodwater after being buffered by the energy dissipation pool 9 can be flexibly distributed according to actual needs. When the floodwater quality meets the irrigation requirements and the water storage device 33 is not full, part of the floodwater is guided into the water storage device 33 for regulation and storage, realizing the resource utilization of floodwater. When the water quality does not meet the standards or the water storage device 33 is full, the floodwater is directly discharged to the drainage system outside the tunnel 16 through the outlet ditch 11, ensuring that flood discharge safety is given priority. This avoids the impact of blind water storage on flood discharge safety and makes full use of rainwater resources to provide water for slope irrigation during the dry season, realizing flood control safety and ecological maintenance. The water collection and diversion device 29 is set after the energy dissipation pool 9, utilizing the deceleration and buffering effect of the energy dissipation pool 9 to make the water flow entering the diversion device more stable.

[0039] Specifically, the water collection and diversion device 29 includes a valve assembly, a channel assembly, and a filter and sedimentation assembly 32. The channel assembly includes a connecting channel 31 and a discharge ditch 11. One end of the connecting channel 31 is connected to the energy dissipation tank 9, and the other end is connected to the water storage device 33. One end of the discharge ditch 11 is connected to the energy dissipation tank 9, and the other end is connected to the external drainage system of the tunnel 16. The connecting channel 31 and the discharge ditch 11 are set independently, forming a structure in parallel for the water storage channel and the flood discharge channel. By setting the connecting channel 31, floodwater can be introduced into the water storage device 33. By setting the discharge ditch 11, excess water or water that does not meet the water quality requirements can be directly discharged. This design makes the water storage function and the flood discharge function independently designed, avoiding interference between diversion and flood discharge, and ensuring that flood discharge safety is given priority. The valve assembly includes a first diversion valve 10. The first diversion valve 10 is located on the connecting channel 31 and is used to control the opening or closing of the connecting channel 31. The second diversion valve 30 is located on the outlet ditch 11 and is used to control the opening or closing of the outlet ditch 11. The first diversion valve 10 and the second diversion valve 30 are controlled independently and work together. When the flood water quality meets the irrigation requirements and the water storage equipment 33 is not full, the first diversion valve 10 is opened and the second diversion valve 30 is closed, so that all the water flows into the water storage equipment 33. When the water quality does not meet the standards or the water storage equipment 33 is overflowing, the first diversion valve 10 is closed and the second diversion valve 30 is opened, so that all the water flows out through the outlet ditch 11. When partial diversion is required, the water volume can be distributed on demand by adjusting the opening ratio of the first diversion valve 10 and the second diversion valve 30. The independent control of the first diversion valve 10 and the second diversion valve 30 allows the diversion strategy to be finely adjusted according to various factors such as flood water quality, the status of the water storage equipment 33, and irrigation needs. The filter and sedimentation assembly 32 is installed on the connecting channel 31 and is used to filter impurities flowing to the water storage equipment 33. The water flowing to the water storage equipment 33 is filtered and purified, effectively intercepting suspended particles, silt, and some pollutants in the flood, preventing impurities from entering the water storage equipment 33 and causing siltation and water quality deterioration.

[0040] It should also be noted that both the first diversion valve 10 and the second diversion valve 30 are electric butterfly valves. The electric butterfly valves can be opened at any angle from 0° to 90°. By adjusting the opening ratio, the amount of water entering the water storage equipment 33 and the external drainage system of the tunnel 16 can be precisely controlled to meet the fine-tuning requirements of partial diversion and on-demand distribution.

[0041] It should also be noted that the external drainage system of Tunnel 16 includes one or more of the following: natural gullies, rivers, low-lying areas, drainage canals, culverts, and drainage pipe networks. This design allows for the safe discharge of floodwaters.

[0042] Among them, the water storage device 33 is an underground water storage tank or a ground water storage ditch, and the water storage device 33 is equipped with an inspection hole to inspect the inside of the water storage device 33.

[0043] The filtration and sedimentation assembly 32 includes a coarse filter layer, a fine filter layer, a water collection layer, and a stainless steel filter screen. The coarse filter layer, fine filter layer, and water collection layer are sequentially arranged within the connecting channel 31. The coarse filter layer is used to intercept large-diameter suspended solids and retain silt. It is filled with volcanic rock material with a particle size of 30mm-50mm for pre-filtering. The volcanic rock material is hard, erosion-resistant, and can withstand flood impacts without easily breaking, maintaining long-term stable filtration performance. The fine filter layer is used to adsorb fine particulate matter. It is filled with maifanite filter media with a particle size of 8mm-20mm. To achieve deep adsorption, and because maifanite can slowly release trace elements such as calcium, magnesium, iron, and silicon, it has a certain regulating effect on the pH value of the water, making the effluent water quality more suitable for slope vegetation irrigation; the water collection layer is used to collect the filtered water. The water collection layer is made of quartz sand with a particle size of 3-7mm, which is used for end collection; the stainless steel filter screen is set in the connecting channel 31, and the stainless steel filter screen is set between the coarse filter layer and the fine filter layer, and between the fine filter layer and the water collection layer. By setting the stainless steel filter screen, the filter media can be prevented from mixing, and the fine filter media can be prevented from falling into the lower layer under the action of gravity or water flow, so as to maintain the independent function of each layer.

[0044] In some embodiments, the filter grit chamber 32 may also use only a gravel reverse filter layer to achieve the filtration effect.

[0045] In some embodiments, the ecological irrigation component is connected to the water storage device 33 so that the water in the water storage device 33 enters the ecological irrigation component to irrigate the slope vegetation layer; a complete closed loop of drainage, water storage and water use is constructed, which can transform the originally discharged flood into a stable water source for the slope vegetation during the dry season or non-flood season, and realize the synergistic unity of flood control safety and ecological maintenance.

[0046] Specifically, the ecological irrigation component includes an irrigation main pipe 34 and a seepage pipe 35. The irrigation main pipe 34 is connected to the outlet of the water storage device 33, and an anti-backflow device is installed between the irrigation main pipe 34 and the water storage device 33. The seepage pipe 35 is connected to the irrigation main pipe and is laid in the vegetation layer of the slope. Multiple evenly distributed water outlet holes 5 are opened on the seepage pipe 35. Water in the water storage device 33 is transported to each irrigation area through the irrigation main pipe 34. The seepage pipe 35 is connected to the irrigation main pipe 34 and distributed along the vegetation layer of the slope to achieve seepage irrigation of the vegetation layer of the slope. Moreover, by setting up an anti-backflow device, the irrigation water is prevented from flowing back into the water storage device 33 due to siphon or gravity when the water supply is stopped. This effectively avoids the backflow of soil particles, microorganisms or root exudates remaining in the irrigation main pipe 34 into the water storage device 33, ensuring that the water quality in the water storage device 33 is not polluted.

[0047] The backflow prevention device is a one-way valve, which prevents water in the irrigation main pipe 34 from flowing back into the water storage device 33. The one-way opening and closing mechanism of the valve ensures that water can only flow from the water storage device 33 to the irrigation main pipe 34, fundamentally eliminating the possibility of backflow of contaminants. Irrigation can be started and stopped according to soil moisture content, season, or manual instructions. A washable filter and maintenance valve are installed between the water storage device 33 and the ecological irrigation components for easy maintenance during operation.

[0048] Based on the same inventive concept, this application also provides a drainage method for the 16th tunnel entrance, comprising the following steps: S1: Collects floodwaters through drainage pit 1; S2: Real-time monitoring of water flow and water level in sink 1, comparing the monitored water flow with the preset water flow threshold, and comparing the water level in sink 1 with the preset water level threshold.

[0049] It should also be noted that the water catchment threshold is further divided into the first water catchment threshold Q1 and the second water catchment threshold Q2, and the water level threshold is further divided into the first water level threshold h1 and the second water level threshold h2. The monitored water flow rate Q is compared with the first water catchment threshold Q1 and the second water catchment threshold Q2, and the water level h of the water catchment pit 1 is compared with the first water level threshold h1 and the second water level threshold h2.

[0050] S3: When the monitored water flow is less than the water flow threshold or the water level in the water collection pit 1 is less than the water level threshold, the floodwater seeps into the sand-free large-pore concrete 22 through the ecological infiltration layer 4, and then is led out of the tunnel 16 through the core-extractable permeable pipe 21, realizing ecological absorption and underground drainage.

[0051] S4: When the monitored water flow exceeds the water flow threshold or the water level in the water collection pit 1 exceeds the water level threshold, the floodwaters are collected in the water collection pit 1 through the open channel 28, and then enter the energy dissipation staircase 8. The water flow dissipates energy step by step along the energy dissipation staircase 8 and then flows into the energy dissipation pool 9, and then is discharged to the drainage system outside the tunnel 16 through the outlet ditch. At the same time, the floodwaters seep into the sand-free large-pore concrete 22 through the ecological infiltration layer 4, and then are led out of the tunnel 16 through the core-extractable permeable pipe 21, realizing ecological absorption and underground infiltration and drainage.

[0052] Specifically, when the water flow rate Q is less than Q1 or the water level h of the water collection pit 1 is less than h1, the flood is small in scale and is absorbed by the ecological infiltration layer 4 of the open channel 28 and the sand-free large-pore concrete 22 drainage layer. When Q1≤Q≤Q2 or h1≤h≤h2, the flood is of medium scale. Part of the flood is absorbed by the ecological infiltration layer 4 and the sand-free large-pore concrete 22 drainage layer of the open channel 28. Another part of the flood is collected in the water collection pit 1 through the open channel 28, and then enters the energy dissipation step 8. The water flow dissipates energy step by step along the energy dissipation step 8 and then flows into the energy dissipation pool 9, and then is discharged to the external drainage system of the tunnel 16 through the outlet ditch.

[0053] When Q > Q2 or h > h2, the flood level is large. The floodwaters are collected in the collection pit 1 through the open channel 28, and then enter the energy dissipation staircase 8. The water flow dissipates energy step by step along the energy dissipation staircase 8 and then flows into the energy dissipation pool 9. Finally, it is discharged to the drainage system outside the tunnel 16 through the outlet ditch. At the same time, the floodwaters seep into the sand-free large-pore concrete 22 through the ecological infiltration layer 4, and then are led out of the tunnel 16 through the core-extractable permeable pipe 21, realizing ecological absorption and underground infiltration and drainage.

[0054] The first catchment threshold Q1, the second catchment threshold Q2, the first water level threshold h1, and the second water level threshold h2 are calculated based on the catchment area A above the tunnel entrance, the runoff coefficient φ, and the rainfall intensity i. The specific formula is Q=φ·i·A. Preferably, Q1 is 0.05~0.30m³ / s, Q2 is 0.30~1.50m³ / s, h1 is 0.15~0.30m, and h2 is 0.60~1.20m. The above values ​​can be modified in combination with engineering examples, topography, and safety level.

[0055] S5: When the flood water quality meets the irrigation requirements and the water storage equipment 33 is not full, the first diversion valve 10 is opened to allow some floodwater to enter the water storage equipment 33; when the flood water quality does not meet the requirements or the water storage equipment is full, the first diversion valve 10 is closed and the second diversion valve 30 is opened to allow the floodwater to be discharged through the outlet ditch 11 to the external drainage system of the tunnel 16.

[0056] S6: The slope vegetation layer is irrigated by the irrigation main pipe 34 and the seepage irrigation pipe 35 to realize the recycling of flood resources.

[0057] 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, improvements, etc., 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 device for tunnel entrances, characterized in that, It includes water collection components, diversion and storage components, drainage and energy dissipation components, ecological irrigation components, open channel trough (28), and portal wall (12), among which, The open-cut channel (28) is set along the axial direction of the tunnel (16); The water collection component is disposed on the open channel (28), and the water collection component includes a plurality of water collection pits (1); The portal wall (12) is set along the axial direction of the tunnel (16) and embedded in the mountain (17), and is arranged in sequence with the open tunnel (28). Several end wall notches (19) are opened on the portal wall (12), and the end wall notches (19) are set one-to-one with the water collection pit (1). The drainage energy dissipation component is arranged along the axial direction of the tunnel (16). The drainage energy dissipation component includes an energy dissipation staircase (8) and an energy dissipation pool (9). The water inlet end of the energy dissipation staircase (8) is connected to the end wall gap (19), and the water outlet end of the energy dissipation staircase (8) is connected to the water inlet end of the energy dissipation pool (9). The diversion and storage component includes a water collection and diversion device (29) and a water storage device (33). One end of the water collection and diversion device (29) is connected to the energy dissipation pool (9), and the other end of the water collection and diversion device (29) is connected to the water storage device (33). The ecological irrigation component is connected to the water storage device (33) so that the water in the water storage device (33) enters the ecological irrigation component to irrigate the slope vegetation layer.

2. The tunnel entrance drainage device according to claim 1, characterized in that, The open channel (28) includes a first open channel (2), a second open channel (3), and an ecological infiltration layer (4), wherein, The first open-cut channel (2) is made of sand-free large-pore concrete (22). Several water collection pits (1) are arranged linearly along the first open-cut channel (2). A core-extractable permeable pipe (21) is installed in the first open-cut channel (2). The core-extractable permeable pipe (21) passes through the portal wall (12) and extends to the outside of the tunnel (16) so that the seepage water can be discharged outside the tunnel (16) through the core-extractable permeable pipe (21). The second open channel (3) and the first open channel (2) are arranged in sequence. The second open channel (3) is located on the side of the first open channel (2) away from the portal wall (12). A water sealing layer (24) is provided on the second open channel (3). The water sealing layer (24) is made of rock and soil material. The water sealing layer (24) is used to reduce surface water leakage. The ecological infiltration layer (4) is set on the ground surface around the first open channel (2), and the bottom surface of the ecological infiltration layer (4) is connected to the sand-free macroporous concrete (22).

3. A tunnel entrance drainage device according to claim 2, characterized in that, The ecological infiltration layer (4) includes a greening layer (23), a permeable substrate layer, and a drainage layer, wherein, The drainage layer is connected to the sand-free macroporous concrete (22), and the drainage layer is used to collect the infiltrated water after being filtered by the permeable matrix layer; The permeable matrix layer is disposed on the top surface of the drainage layer; The greening layer (23) is set on the top surface of the permeable matrix layer.

4. A drainage device for the entrance of a tunnel (16) according to claim 1, characterized in that, The interior of the portal wall (12) is provided with integral reinforcement (26), which includes several equally spaced steel bars, and the bottom of the portal wall (12) is provided with micro pile foundation (27).

5. A tunnel entrance drainage device according to claim 1, characterized in that, The drainage and energy dissipation components also include buttresses (7), baffles (25), and handrails, wherein, The buttress wall (7) is located on both sides of the energy dissipation staircase (8); The handrail is located at the top of the buttress wall (7); The water baffle (25) is disposed on both sides of the energy dissipation staircase (8), and the height of the water baffle (25) is higher than the height of the buttress wall (7), and the water baffle (25) is located outside the buttress wall (7). The water baffle (25) is used to adjust the height of the water passage section in the energy dissipation staircase (8).

6. A tunnel entrance drainage device according to claim 1, characterized in that, The water collection and diversion device (29) includes a valve assembly, a channel assembly, and a filter and sedimentation assembly (32), wherein, The channel assembly includes a connecting channel (31) and an outlet ditch (11). One end of the connecting channel (31) is connected to the energy dissipation pool (9), and the other end is connected to the water storage device (33). One end of the outlet ditch (11) is connected to the energy dissipation pool (9), and the other end is connected to the external drainage system of the tunnel. The valve assembly includes a first diversion valve (10) and a second diversion valve (30). The first diversion valve (10) is disposed on the connecting channel (31) and is used to control the opening or closing of the connecting channel (31). The second diversion valve (30) is disposed on the outlet channel (11) and is used to control the opening or closing of the outlet channel (11). The filter and sedimentation assembly (32) is disposed on the connection channel (31) and is used to filter impurities flowing to the water storage device (33).

7. A tunnel entrance drainage device according to claim 6, characterized in that, The filter and sedimentation assembly (32) includes a coarse filter layer, a fine filter layer, a water collection layer, and a stainless steel filter screen. The coarse filter layer, the fine filter layer, and the water collection layer are sequentially arranged within the connecting channel (31). The coarse filter layer is used to intercept large-diameter suspended solids and retain silt and sand, and the coarse filter layer is filled with volcanic rock material; The fine filter layer is used to adsorb fine particulate matter, and the fine filter layer is filled with maifan stone filter media. The water collection layer is used to collect filtered water and is made of quartz sand. The stainless steel filter screen is disposed in the connecting channel (31), and the stainless steel filter screen is disposed between the coarse filter layer and the fine filter layer, and between the fine filter layer and the water collection layer.

8. A tunnel entrance drainage device according to claim 1, characterized in that, The ecological irrigation component includes an irrigation main pipe (34) and a drip irrigation pipe (35), wherein, The irrigation main pipe (34) is connected to the outlet of the water storage device (33), and an anti-backflow device is provided between the irrigation main pipe (34) and the water storage device (33); The drip irrigation pipe (35) is connected to the main irrigation pipe (34). The drip irrigation pipe (35) is laid in the vegetation layer of the slope. The drip irrigation pipe (35) has multiple evenly distributed water outlet holes (5).

9. A tunnel entrance drainage device according to claim 1, characterized in that, The top of the energy dissipation pool (9) is provided with an opening, and an openable cover plate (20) is provided at the opening.

10. A method for drainage at a tunnel entrance, applied to a tunnel entrance drainage device as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Collect floodwaters through a drainage pit (1); S2: Real-time monitoring of the water flow and the water level of the water collection pit (1), and comparing the monitored water flow with the preset water collection threshold, and comparing the water level of the water collection pit (1) with the preset water level threshold; S3: When the monitored water flow is less than the water flow threshold or the water level in the water collection pit (1) is less than the water level threshold, the floodwater seeps into the sand-free large-pore concrete (22) through the ecological infiltration layer (4), and then is led out of the tunnel (16) through the core-extractable permeable pipe (21) to achieve ecological absorption and underground drainage. S4: When the monitored water flow rate is greater than the water flow threshold or the water level in the water collection pit (1) is greater than the water level threshold, the floodwaters are collected in the water collection pit (1) through the open channel (28), and then enter the energy dissipation staircase (8). The water flow is dissipated step by step along the energy dissipation staircase (8) and then flows into the energy dissipation pool (9), and then is discharged to the drainage system outside the tunnel (16) through the outlet ditch. At the same time, the floodwaters seep into the sand-free large-pore concrete (22) through the ecological infiltration layer (4), and then are led out of the tunnel (16) through the core-extractable permeable pipe (21), realizing ecological absorption and underground infiltration and drainage. S5: When the flood water quality meets the irrigation requirements and the water storage equipment (33) is not full, the first diversion valve (10) is opened to allow some floodwater to enter the water storage equipment (33); when the flood water quality does not meet the requirements or the water storage equipment is full, the first diversion valve (10) is closed and the second diversion valve (30) is opened to allow the floodwater to be discharged to the drainage system outside the tunnel through the outlet ditch (11); S6: The slope vegetation layer is irrigated by the irrigation main pipe (34) and the seepage irrigation pipe (35) to realize the recycling of flood resources.

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