A drainage and waterproofing system for existing mountain tunnel sprayed sections

Abstract

This invention provides a drainage and waterproofing system for existing mountain tunnel sprayed sections. Several system drainage holes are evenly arranged on the tunnel wall of the seepage section, perpendicular to the tunnel's axis. Several drainage pipes are inserted one-to-one into each system drainage hole, and the gap between the outer wall of the drainage pipe and the opening of the system drainage hole is sealed. Several permeable pipes are arranged in a ring at equal intervals on the inner wall of the tunnel. Each drainage pipe is connected to the permeable pipes via a direct connection or a connecting pipe. Both ends of the permeable pipes extend to drainage channels to collect seepage water and guide it into the drainage channels. Two drainage channels are respectively set on both sides of the tunnel arch bottom to drain seepage water. A waterproof layer is laid on the inner wall surface of the tunnel and covers the permeable pipes and connecting pipes. The sealing layer is a reinforced concrete layer, sealed outside the waterproof layer. This system is suitable for drainage and waterproofing in mountain tunnels, ensuring tunnel durability and extending tunnel life.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, specifically to a drainage and waterproofing system for the sprayed section of an existing mountain tunnel. Background Technology

[0002] Existing tunnel waterproofing and drainage measures consist of "blocking, diverting, and draining." A publicly disclosed invention patent, "A Construction Method for Leakage Prevention and Control in Existing Tunnels (CN 118187941A)," relates to the field of municipal secondary lining tunnel treatment technology, and includes construction steps such as plugging, diverting, and draining. Pluging involves filling expansion joints with sealant and grouting material, installing water-stop strips, grouting for sealing, and applying waterproof coating to the surface. Diverting involves installing diversion channels at the expansion joints on the tunnel walls and roof. Draining involves cutting a groove below the safety passage door in the central partition wall, burying water pipes, connecting the butterfly-shaped side ditch of the central wall to the drainage ditch inside the safety passage of the central partition wall through the water pipes, draining water into a rainwater well through the drainage ditch, and finally draining the water out through a pump in the rainwater well. The Shenzhen pumped storage power station's traffic tunnel seepage control project addresses the seepage characteristics by adopting a comprehensive approach to tunnel leakage management, prioritizing drainage while combining prevention, drainage, blocking, and interception. This involves using sunshades to cover the seepage surface and employing stainless steel seepage canopies to intercept and collect the seepage before diverting it to drainage ditches on both sides of the tunnel via drainage pipes. However, this project employs temporary drainage and waterproofing measures, which have two drawbacks: potential for future problems and a lack of permanent waterproofing, plus the need to encroach on the tunnel's construction boundary.

[0003] The Kayan Highway Tunnel is located in the southwest, with a considerable burial depth and abundant groundwater. Localized seepage is severe, and the overall integrity of the surrounding rock is poor, causing groundwater to seep into the tunnel through fissures. Furthermore, the high calcium ion content in the groundwater leads to oxidation, forming a crystalline layer on the road surface, causing slippage and severely impacting driving safety. The surrounding rock is primarily characterized by an inlaid, fragmented structure or layered distribution. Existing technologies, such as adding internal waterproofing (e.g., applying waterproof coatings), grooving, pre-burying blind pipes for drainage, cement grouting, high-elasticity nano-waterproofing material grouting, and pre-grouting to seal fissures, fail to achieve the goal of unobstructed and permanent drainage of fissure water.

[0004] The above-mentioned projects have all adopted unique treatment methods to meet construction needs based on their terrain characteristics. Although they share a common basic concept, they are not universally applicable at the operational level. In mountainous terrain, the internal structure of the mountain is intricate and complex, and the seepage points are scattered and have many branches, which is a current challenge for mountain tunnels.

[0005] This application seeks to develop a drainage and waterproofing system suitable for the sprayed section of mountain tunnels, in order to meet the terrain requirements of mountain tunnels. Utility Model Content

[0006] The purpose of this utility model is to address the shortcomings of existing technologies by providing a drainage and waterproofing system for existing mountain tunnel sprayed sections, which includes buried pipe drainage, internal waterproofing and seepage prevention, and external curing and sealing to ensure waterproofing capabilities, thereby ensuring the durability and safety of the tunnel.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is: an existing mountain tunnel spraying section waterproofing and drainage system, including several system drainage holes, several drainage pipes, several connecting pipes, several permeable pipes, two drainage channels, a waterproof layer and a sealing layer. Several drainage holes of the system are evenly arranged on the tunnel wall of the seepage section of the tunnel, perpendicular to the tunnel axis; Several drain pipes are inserted into the drain holes of each system in a corresponding manner, and the gap between the outer wall of the drain pipe and the opening of the drain hole of the system is sealed. Several permeable pipes are arranged in a ring at equal intervals on the inner wall of the tunnel. Each drainage pipe is connected to the permeable pipe by a direct connection or by a connecting pipe. Both ends of the permeable pipe extend to the drainage ditch to collect the seepage water from the drainage pipe and guide it into the drainage ditch. The two drainage channels are respectively located on both sides of the tunnel arch bottom to drain seepage water. The waterproof layer is laid on the inner wall surface of the tunnel and covers the permeable pipe and connecting pipe; The sealing layer is a reinforced concrete layer with wire mesh, which is sealed outside the waterproof layer.

[0008] Preferably, the depth of the drainage hole in the system is ≥300cm.

[0009] Preferably, in severely water-seeping sections of the tunnel, randomly located drainage holes are also provided. Drainage pipes are installed in the random drainage holes, and the gap between the outer wall of the drainage pipe and the opening of the random drainage hole is sealed. The random drainage holes are connected to adjacent permeable pipes through connecting pipes.

[0010] Preferably, the waterproof layer includes a non-woven geotextile and a waterproof membrane. The non-woven geotextile is laid on the inner wall surface of the tunnel, and the waterproof membrane is fixed to the inner wall of the tunnel by steel arch ribs or bridge expansion bolts and anchor plates.

[0011] Preferably, the location where the expansion bolts of the cable tray penetrate the waterproof membrane is sealed with polyurethane expansion sealant and a shotcrete sealing layer.

[0012] Preferably, the reinforcing steel bars in the reinforced concrete mesh are φ6mm steel bars, and the mesh size is 15cm x 15cm.

[0013] Preferably, the permeable pipe is fixed to the inner wall of the tunnel by stainless steel strips and nails.

[0014] Preferably, the drain pipe is a Φ25 HDPE drain pipe with a length of L≥60cm.

[0015] Preferably, the joints of the drain pipe, connecting pipe and permeable pipe are sealed by wrapping and filling with non-woven fabric.

[0016] Preferably, the nonwoven geotextile has a strength of 15 kN / m, and the waterproofing membrane is a 1.5 mm EVA composite waterproofing membrane.

[0017] This utility model has substantial features and advancements compared to existing technologies. Specifically, targeting the characteristics of mountainous terrain, this utility model constructs a system of drainage holes in seepage sections, buries drainage pipes for drainage, and collects seepage water through connecting pipes and permeable pipes before introducing it into a drainage ditch for discharge, thus achieving the purpose of drainage through buried pipes. Then, a waterproof layer is laid on the inner wall of the tunnel for waterproofing, and the outermost layer is sealed and cured with reinforced concrete mesh. While ensuring tunnel safety and quality, this utility model effectively solves the waterproofing problem of mountain highway tunnels in a safe, fast, efficient, and high-quality manner, improving the tunnel's waterproofing capacity and ensuring its durability and safety.

[0018] Furthermore, in areas with high permeability, random drainage holes are added to enhance drainage capacity; at the expansion bolts of the cable tray in the waterproof layer, waterproofing treatment is strengthened to prevent water seepage caused by construction. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an existing drainage and waterproofing system for sprayed sections of mountain tunnels, as described in this utility model.

[0020] Figure 2 This is a partial cross-sectional view of an existing mountain tunnel spraying section waterproofing and drainage system according to this utility model.

[0021] Figure 3 This is a schematic diagram of the installation of the permeable pipe in this utility model.

[0022] Figure 4 This is a schematic diagram of the waterproofing treatment at the expansion bolts of the cable tray in this utility model.

[0023] In the diagram: 1. System drainage hole; 2. Drainage pipe; 3. Connecting pipe; 4. Permeable pipe; 5. Drainage ditch; 6. Waterproof layer; 7. Sealing layer; 8. Polyurethane expansion sealant and shot ramming sealing layer; 41. Stainless steel strip; 42. Nail. Detailed Implementation

[0024] The technical solution of this utility model will be further described in detail below through specific embodiments.

[0025] like Figures 1-4As shown, an existing mountain tunnel sprayed section waterproofing and drainage system includes several system drainage holes 1, several drainage pipes 2, several connecting pipes 3, several permeable pipes 4, two drainage channels 5, a waterproof layer 6, and a sealing layer 7.

[0026] Several system drainage holes 1 are evenly arranged on the tunnel wall of the seepage section of the tunnel, perpendicular to the tunnel axis. The depth of the system drainage holes 1 is ≥300cm. In this embodiment, its diameter is 36mm.

[0027] In areas with severe water seepage, additional random drainage holes can be added to enhance drainage capacity through a dense network of holes.

[0028] Several drainage pipes 2 are inserted one-to-one into each system drainage hole 1 and random drainage holes, and the gap between the outer wall of the drainage pipe and the opening of the system drainage hole is sealed. The sealing method can be concrete pouring. The port of the drainage pipe 2 can be wrapped with filter cloth to avoid pipe blockage.

[0029] Several permeable pipes 4 are arranged in a ring at equal intervals on the inner wall of the tunnel. Each drainage pipe 2 is connected to the permeable pipe 4 by direct connection or by connecting pipe 3. Both ends of the permeable pipe 4 extend to the drainage ditch 5 to collect the seepage water from the drainage pipe 2 and guide it into the drainage ditch 5. The joints of the drainage pipe 2, connecting pipe 3 and permeable pipe 4 are sealed by wrapping and filling with non-woven fabric.

[0030] In this embodiment, the drainage pipe is a Φ25HDPE drainage pipe with an L≥60cm, and the permeable pipe is a 50mm flexible permeable pipe. The permeable pipe 4 is fixed to the inner wall of the tunnel by a stainless steel strip 41 and a nail 42.

[0031] The two drainage channels 5 are respectively set on both sides of the tunnel arch bottom to drain seepage water.

[0032] The waterproof layer 6 is laid on the inner wall surface of the tunnel and covers the permeable pipe 4 and connecting pipe 3. In this embodiment, the waterproof layer 6 includes a non-woven geotextile and a waterproof membrane. The non-woven geotextile is laid on the inner wall surface of the tunnel, and the waterproof membrane is fixed to the inner wall of the tunnel by steel arch ribs or bridge expansion bolts and anchor plates. The non-woven geotextile is 15kN / m thick, and the waterproof membrane is a 1.5mm EVA composite waterproof membrane. At the location of the bridge expansion bolts, where the waterproof membrane penetrates, polyurethane expansion sealant and a shotcrete sealing layer 8 are sealed.

[0033] The sealing layer 7 is a reinforced concrete layer with wire mesh, which is sealed outside the waterproof layer. The reinforcing bars of the wire mesh concrete are φ6mm steel bars, and the mesh size is 15cm x 15cm.

[0034] The construction process is as follows: 1) Construction of system drainage holes and random drainage holes Add Φ36 system drainage holes to the seepage section, L=300cm@3mX3m, and add random drainage holes to the sections with severe local seepage. Insert L=60cm, Φ25HDPE drainage pipes into the system and random drainage holes.

[0035] 2) Construction of connecting pipes and circumferential drainage pipes The system drainage pipes and random drainage pipes are connected to the circumferential Φ50 flexible permeable pipes via plastic elbows and plastic tees using Φ25 HDPE connecting pipes, diverting accumulated water to the longitudinal drainage channels on both sides of the tunnel arch bottom for discharge outside the tunnel. The joints of the drainage pipes or flexible hoses are wrapped with non-woven fabric and then tightly sealed to the tee or elbow.

[0036] The Φ50 flexible permeable pipe is installed in a full-section circumferential manner. The circumferential drainage hose is made of stainless steel strips @1m-2x50x300 (mm), and cement nails are symmetrically driven in at 30cm intervals to secure it.

[0037] 3) Laying of non-woven geotextile and waterproof membrane After the drainage system was constructed, a non-woven geotextile and a waterproof membrane were laid across the entire outer section of the existing support layer in the seepage section. The non-woven geotextile used was 15kN / m, and the waterproof membrane was a 1.5mm EVA composite waterproof membrane, fixed using φ22 steel arch ribs, cable tray expansion bolts, and anchor plates. The longitudinal reinforcement of the steel arch ribs was 2φ22@15cm, and the transverse reinforcement was φ16@30cm. A 15cmx15cmx3cm water-stop rubber sheet was added between the anchor plates and the waterproof membrane. Special waterproofing treatment was applied to the penetration points of the cable tray embedded parts and waterproof membrane fixing anchors, with polyurethane expansion sealant applied at the penetration points, and then sealed with shotcrete after curing.

[0038] 4) Apply wire mesh and spray concrete for curing and sealing. Lay Φ6 reinforcing steel mesh @15cmX15cm on the outside of the waterproof membrane, and then spray 16cm thick C25 concrete to seal it.

[0039] Finally, it should be noted that: the preferred embodiments of this patent have been described in detail above, but this patent is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this patent.

Claims

1. A waterproofing and drainage treatment system for a sprayed section of an existing mountain tunnel, characterized by: It includes several system drainage holes, several drainage pipes, several connecting pipes, several permeable pipes, two drainage channels, a waterproof layer, and a sealing layer; Several drainage holes of the system are evenly arranged on the tunnel wall of the seepage section of the tunnel, perpendicular to the tunnel axis; Several drain pipes are inserted into the drain holes of each system in a corresponding manner, and the gap between the outer wall of the drain pipe and the opening of the drain hole of the system is sealed. Several permeable pipes are arranged in a ring at equal intervals on the inner wall of the tunnel. Each drainage pipe is connected to the permeable pipe by a direct connection or by a connecting pipe. Both ends of the permeable pipe extend to the drainage ditch to collect the seepage water from the drainage pipe and guide it into the drainage ditch. The two drainage channels are respectively located on both sides of the tunnel arch bottom to drain seepage water. The waterproof layer is laid on the inner wall surface of the tunnel and covers the permeable pipe and connecting pipe; The sealing layer is a reinforced concrete layer with wire mesh, which is sealed outside the waterproof layer.

2. The waterproofing and drainage treatment system for the sprayed section of an existing mountain tunnel according to claim 1, characterized in that: The depth of the drainage hole in the system is ≥300cm.

3. The waterproofing and drainage treatment system for the sprayed section of an existing mountain tunnel according to claim 1, characterized in that: In severely water-seeping sections of the tunnel, randomly located drainage holes are also installed. Drainage pipes are installed in the drainage holes, and the gap between the outer wall of the drainage pipe and the opening of the drainage hole is sealed. The drainage holes are connected to adjacent permeable pipes through connecting pipes.

4. The waterproofing and drainage treatment system for the sprayed section of an existing mountain tunnel according to claim 1, characterized in that: The waterproof layer includes a non-woven geotextile and a waterproof membrane. The non-woven geotextile is laid on the inner wall surface of the tunnel, and the waterproof membrane is fixed to the inner wall of the tunnel by steel arch ribs or bridge expansion bolts and anchor plates.

5. The waterproofing and drainage treatment system for the sprayed section of an existing mountain tunnel according to claim 4, characterized in that: At the expansion bolts of the cable tray, the area penetrating the waterproof membrane is sealed with polyurethane expansion sealant and a shotcrete sealing layer.

6. The waterproofing and drainage treatment system for the sprayed section of an existing mountainous tunnel according to claim 5, characterized in that: The reinforcing steel bars used in the concrete mesh are φ6mm steel bars, and the mesh size is 15cm x 15cm.

7. The waterproofing and drainage treatment system for the sprayed section of an existing mountain tunnel according to claim 1, characterized in that: The permeable pipe is fixed to the inner wall of the tunnel by stainless steel strips and nails.

8. The waterproofing and drainage treatment system for the sprayed section of an existing mountain tunnel according to claim 1, characterized in that: The drainage pipe is a Φ25 HDPE drainage pipe with a length of L≥60cm.

9. The waterproofing and drainage treatment system for the sprayed section of an existing mountain tunnel according to claim 1, characterized in that: The joints of the drainage pipe, connecting pipe, and permeable pipe are sealed by wrapping and filling with non-woven fabric.

10. The waterproofing and drainage treatment system for the sprayed section of an existing mountain tunnel according to claim 4, characterized in that: The nonwoven geotextile uses 15kN / m, and the waterproofing membrane uses 1.5mm EVA composite waterproofing membrane.

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