Double-layer waterproof structure of super-large underground excavation cave warehouse tunnel engineering

Abstract

The utility model relates to a kind of super large tunneling hole warehouse tunnel engineering double-layer waterproof structure, including initial support, secondary lining, and the composite waterproof layer being set between initial support and secondary lining, the composite waterproof layer includes buffer layer, primary waterproof layer, secondary waterproof layer, the buffer layer is fixed in the outer surface of initial support, buffer layer and initial support between laying have anti-clogging drainage blind pipe network;Flow guide unit is equipped in the drainage blind pipe network, the primary waterproof layer is fixed on the side of buffer layer far from initial support;The secondary waterproof layer is fixedly bonded on the side of primary waterproof layer far from initial support by adhesive layer, forms double-layer waterproof system.The utility model forms double waterproof barrier, effectively blocks groundwater penetration, improves waterproof reliability;Three-dimensional drainage system is set between waterproof layer and initial support, moisture invading waterproof layer is promptly discharged, prevent water extrusion, block external water intrusion concrete lining structure.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, specifically to a double-layer waterproof structure for ultra-large underground tunnel projects. Background Technology

[0002] Tunnels are engineering structures buried underground, representing a form of human utilization of underground space. Based on their function, tunnels can be mainly classified as traffic tunnels, hydraulic tunnels, and municipal tunnels. Lining refers to the permanent support structure constructed around the tunnel body using reinforced concrete and other materials to prevent deformation or collapse of the surrounding rock. Waterproofing of the lining is primarily achieved through secondary lining and initial support, as well as a waterproof layer between the secondary lining and initial support. The construction of tunnels disrupts the original water system balance of the mountain, turning the tunnel into a conduit for groundwater accumulation near the mountain it passes through. When a tunnel connects with aquifers, waterproofing treatment is necessary.

[0003] Patent "CN214887124U" discloses a waterproof structure for tunnel lining. Specifically, this solution involves installing drainage pipes within drainage channels in the foundation slab. These pipes are anchored within the initial support's sprayed layer via inserts, allowing water to drain from behind the waterproof layer and preventing seepage. However, this solution uses a single-layer waterproofing method, which suffers from numerous joints and susceptibility to damage, making it difficult to meet the high standard of zero leakage required for tunnel structures.

[0004] Therefore, it is necessary to study a double-layer waterproof structure for ultra-large underground tunnel projects. Utility Model Content

[0005] Therefore, the purpose of this utility model is to provide a double-layer waterproof structure for ultra-large underground tunnel projects, which effectively solves the problems of multiple joints and easy damage in traditional single-layer waterproofing lining, making it difficult to meet the high standard requirement of zero leakage in tunnel structures.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is: a double-layer waterproof structure for ultra-large underground tunnel projects, including initial support, secondary lining, and a composite waterproof layer disposed between the initial support and the secondary lining. The composite waterproof layer includes a buffer layer, a primary waterproof layer, and a secondary waterproof layer. The buffer layer is fixed to the outer surface of the initial support. A drainage blind pipe network to prevent clogging is laid between the buffer layer and the initial support. The output end of the drainage blind pipe network is connected to the central drainage ditch inside the tunnel. A flow guiding unit is provided in the drainage blind pipe network. The flow guiding unit includes a support fixed inside the pipe and a central shaft rotatably mounted on the support. Flow guiding blades are fixed at intervals on the central shaft. The primary waterproof layer is fixed on the buffer layer on the side away from the initial support. An adhesive layer is provided on one side surface of the secondary waterproof layer. The secondary waterproof layer is fixedly bonded to the primary waterproof layer on the side away from the initial support by the adhesive layer, and the secondary waterproof layer and the primary waterproof layer are laid in a staggered manner to form a double-layer waterproof system.

[0007] Furthermore, the buffer layer is a non-woven geotextile, which is smoothly fixed to the initial support base layer by nails with thermoplastic washers.

[0008] Furthermore, the primary waterproof layer is a 1.5mm thick EVA waterproof board, and the secondary waterproof layer is a 1.5mm thick self-adhesive HDPE self-adhesive film.

[0009] Furthermore, the primary waterproof layer is fixed to the buffer layer outside the initial support by using a hot air gun to heat-melt a thermoplastic washer.

[0010] Furthermore, the drainage blind pipe network includes circumferential drainage blind pipes, longitudinal drainage blind pipes, and transverse drainage blind pipes. The circumferential drainage blind pipes are arranged circumferentially along the arc surface of the initial support. The longitudinal drainage blind pipes are arranged longitudinally along the low sidewalls on both sides of the tunnel. The transverse drainage blind pipes are located below the invert arch. The longitudinal drainage blind pipes are connected to the transverse drainage blind pipes and the circumferential drainage blind pipes by two T-joints. The output end of the transverse drainage blind pipes is connected to the central drainage ditch.

[0011] Furthermore, the transverse drainage blind pipe is provided with a flow guiding unit, and the flow guiding blades are spaced apart near the two end openings of the transverse drainage blind pipe.

[0012] Furthermore, geotextile is wrapped around each drainage blind pipe to prevent pollutants from entering the perforated gaps of the blind pipe and causing blockage.

[0013] The beneficial effects of the above technical solution are as follows: The double-layer waterproof structure for ultra-large underground tunnel projects provided by this utility model has the following advantages: 1. Double-layer protection, high reliability: Two layers of waterproof boards are laid in a staggered manner to form a double waterproof barrier, effectively blocking groundwater infiltration and improving waterproof reliability; a three-dimensional drainage system is set between the waterproof layer and the initial support to remove water that has invaded the waterproof layer in time, prevent water compression, and block external water from invading the concrete lining structure.

[0014] 2. Tight joint treatment, no leakage risk: The joints of the waterproof membrane are treated with hot melt welding technology to ensure that the joints are tight and seamless, eliminating the risk of leakage.

[0015] 3. Strong adaptability and wide range of applications: It is suitable for waterproofing projects of cave structures under various geological conditions, especially for cave projects with high waterproofing requirements. Its operation process is simple, construction is convenient, and construction safety and quality are relatively reliable.

[0016] 4. Comprehensive collection and targeted drainage: A network of blind drainage pipes is used to cover the entire area of ​​the tunnel arch, low side walls, and invert arch. All blind pipes are wrapped with geotextile to filter out mud, sand, and gravel carried by seepage water and prevent them from entering the gaps in the pipe holes. A flow guiding unit is also installed in the horizontal blind drainage pipes. The water flow drives the blades to rotate, maintaining smooth drainage and ensuring drainage quality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the waterproof structure of this utility model. Figure 2 for Figure 1 Enlarged structural diagram at point A; Figure 3 This is a schematic diagram of the planar connection structure of a drainage blind pipe network; Figure 4 for Figure 1 Enlarged structural diagram at point B; Figure 5 This is a schematic diagram of the implementation structure of the flow guiding unit.

[0018] Reference numerals: 1-Initial support, 2-Composite waterproof layer, 21-Buffer layer, 22-Primary waterproof layer, 23-Secondary waterproof layer, 3-Secondary lining, 4-Central drainage ditch, 5-Drainage blind pipe network, 51-Circumferential drainage blind pipe, 52-Longitudinal drainage blind pipe, 53-Transverse drainage blind pipe, 6-Flow guiding unit, 61-Support, 62-Central shaft, 63-Flow guiding blade. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1: This example aims to provide a double-layer waterproof structure for ultra-large underground tunnel projects, mainly to solve the problems of numerous joints and easy damage in traditional single-layer waterproofing liner installations, which make it difficult to meet the high-standard waterproofing requirements of underground tunnel structures. Figure 1-5 As shown, the double-layer waterproof structure for the ultra-large underground tunnel project provided in this embodiment includes an initial support 1, a secondary lining 3, and a composite waterproof layer 2 disposed between the initial support 1 and the secondary lining 3. The composite waterproof layer 2 includes a buffer layer 21, a primary waterproof layer 22, and a secondary waterproof layer 23. The buffer layer 21 is fixed to the outer surface of the initial support 1. The primary waterproof layer 22 is fixed to the buffer layer 21 on the side away from the initial support 1. An adhesive layer is provided on one side surface of the secondary waterproof layer 23. The secondary waterproof layer 23 is fixedly bonded to the primary waterproof layer 22 on the side away from the initial support 1 by the adhesive layer. The secondary waterproof layer 23 and the primary waterproof layer 22 are laid in a staggered manner to form a double-layer waterproof system.

[0020] Specifically, such as Figure 4 As shown, in this embodiment, the buffer layer 21 is a non-woven geotextile, which is smoothly fixed to the base layer of the initial support 1 by nails with thermoplastic washers. The primary waterproof layer 22 is a 1.5mm thick EVA waterproof board, and the secondary waterproof layer 23 is a 1.5mm thick self-adhesive HDPE self-adhesive film. During construction, the primary waterproof layer 22 and the secondary waterproof layer 23 are laid in a staggered manner, and the overlap seams of the roll material are sealed with a hot air gun, thereby forming a double waterproof barrier to effectively block groundwater infiltration and improve waterproof reliability.

[0021] Furthermore, a network of blind drainage pipes 5 to prevent clogging is laid between the buffer layer 21 and the initial support 1, such as... Figure 3 As shown, the drainage blind pipe network 5 includes a circumferential drainage blind pipe 51, a longitudinal drainage blind pipe 52, and a transverse drainage blind pipe 53. The circumferential drainage blind pipe 51 is laid out circumferentially along the arc surface of the initial support 1. The longitudinal drainage blind pipe 52 is laid longitudinally along the low sidewalls on both sides of the tunnel. The transverse drainage blind pipe 53 is located below the invert arch. The longitudinal drainage blind pipe 52 is connected to the transverse drainage blind pipe 53 and the circumferential drainage blind pipe 51 by two T-joints. The output end of the transverse drainage blind pipe 53 is connected to the central drainage ditch 4.

[0022] During the initial support construction of the invert arch, a central drainage ditch 4 is installed at the bottom center of the invert arch. The drainage ditch uses reinforced concrete socket pipes with an inner diameter of 50cm. After the drainage ditch is completed, a transverse drainage blind pipe 53 is installed. The transverse drainage blind pipe 53 is connected to the central drainage ditch 4 using a φ100 double-wall perforated corrugated pipe. After the arch wall base surface is treated, circumferential and longitudinal drainage blind pipes 52 are installed. The longitudinal drainage blind pipe 52 uses a φ100 PE double-wall perforated corrugated pipe, and the circumferential drainage blind pipe 51 uses a φ100 semi-circular drainage pipe. The pipe connections are made using tees.

[0023] In addition, to prevent silt and sand from accumulating and clogging the transverse drainage blind pipe 53, this embodiment also provides a flow guiding unit 6 near the openings at both ends of the transverse drainage blind pipe 53, such as... Figure 5 As shown, in this embodiment, the flow guiding unit 6 includes a bracket 61 fixed inside the pipe and a central shaft 62 rotatably mounted on the bracket 61. Flow guiding blades 63 are fixed at intervals on the central shaft 62. With this configuration, when water flows through the transverse drainage blind pipe 53, the water flow impacts the flow guiding blades 63 fixed on the central shaft 62. The force exerted by the water flow on the blades creates a torque, driving the central shaft 62 to rotate around the bracket 61. This causes the flow guiding blades 63 to agitate the water flow and settled sediment particles in the pipe, preventing them from accumulating into a thick silt layer. The rotating blades also lift the bottom sediment, causing it to re-enter the water flow, be carried away by subsequent water flow, and discharged from the pipe. This achieves an automatic sludge removal function, effectively preventing sediment deposition and blockage.

[0024] Working principle explanation: The double-layer waterproof structure for the ultra-large mined tunnel project provided in this embodiment, in actual application, firstly, the base surface of the initial support 1 is treated, and exposed anchor heads, steel pipe heads and other protrusions on the base surface are removed to prevent them from puncturing the waterproof layer; then, after the base surface treatment meets the requirements for waterproof working base surface, the three-dimensional drainage network is constructed. Geotextile is first wrapped around each drainage blind pipe to prevent pollutants from entering the perforated gaps of the blind pipe and causing pipe blockage; then, the longitudinal drainage blind pipes 52 are set along the two low side walls and installed according to the design requirements. Double-wall perforated corrugated pipes are installed along the longitudinal direction of the tunnel. Nail guns are used to fix the pipes to the base surface by nailing nails on the left and right fixing bands of the blind pipes. The longitudinal drainage blind pipe 52 is connected to the transverse drainage blind pipe 53 and the circumferential drainage blind pipe 51 by two T-joints. The output end of the transverse drainage blind pipe 53 is connected to the central drainage ditch 4. Before the construction of the transverse drainage pipe, ensure that the guide unit 6 is fixed inside the pipe. The reserved water guide end is wrapped with geotextile to prevent blockage. When the secondary lining 3 is constructed for drainage, it is connected into a ring. The semi-circular drainage pipe needs to extend 1.5m above the low side wall.

[0025] After the drainage pipes are laid out, a non-woven geotextile buffer layer 21 is laid. During the construction of the buffer layer 21, the longitudinal centerline is first marked on the top of the tunnel arch, and sufficient allowance is left according to the unevenness of the base surface. A waterproof platform is used to lay the non-woven geotextile from the arch to the side walls on both sides. While laying, the non-woven geotextile is fixed to the base surface smoothly and straight using nails with thermoplastic washers (the spacing of the washers is controlled by cross-shaped equidistant control clamps or lines drawn on the non-woven geotextile). The geotextile is arranged in a quincunx pattern, fixed in rows on the left, right, top, and bottom. Additional fixing points are added where the base surface is uneven to ensure that the buffer layer 21 is in close contact with the base surface. Hot melt washers are used to fix the non-woven geotextile at the overlap.

[0026] Next, the composite waterproof layer 2 is laid. The primary waterproof layer 22 is laid from one side wall to the other. The waterproof membrane is firmly welded, with the lower waterproof membrane overlapping the upper one. The tightness of the laying should be moderate, leaving a margin to ensure that the surface of the waterproof membrane adheres closely to the base surface after the concrete is poured. The waterproof membrane is fixed by hot-melt thermoplastic gaskets using a hot air gun. Before welding, a test weld is performed on a plastic sheet to control the welding temperature and speed. The joints are treated first. The overlap joints between the waterproof membranes use double welds to ensure full welds and that the overlap length meets the specifications. After the EVA waterproof membrane is completed, the secondary waterproof layer 23 is constructed after a 30-minute interval. The secondary waterproof layer 23 is bonded and fixed to the primary waterproof layer 22, and the two layers should be staggered by 1 meter. The overlap joints of the membrane are sealed with a hot air gun, thus forming a two-layer waterproof system.

[0027] The double-layer waterproof structure provided in this embodiment for ultra-large underground tunnel projects utilizes the complementary flexibility of EVA and the puncture resistance of HDPE. Combined with overlaps sealed by a hot air gun, this creates a dual waterproof barrier of physical isolation and enhanced sealing, significantly reducing the risk of groundwater infiltration. The design of the diversion unit ensures that water flows into the transverse drainage blind pipe, actively guiding seepage and preventing the formation of water pockets or cavities, further protecting the waterproofing and lining structure. This achieves a high-reliability, long-life, and low-risk waterproofing goal, effectively meeting the waterproofing requirements of the tunnel structure.

[0028] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A double-layer waterproof structure of a super-large underground excavation cave warehouse tunnel project, characterized in that: It includes an initial support (1), a secondary lining (3), and a composite waterproof layer (2) disposed between the initial support (1) and the secondary lining (3). The composite waterproof layer (2) includes a buffer layer (21), a primary waterproof layer (22), and a secondary waterproof layer (23). The buffer layer (21) is fixed to the outer surface of the initial support (1). A drainage blind pipe network (5) to prevent blockage is laid between the buffer layer (21) and the initial support (1); the output end of the drainage blind pipe network (5) is connected to the central drainage ditch (4) in the tunnel, and a flow guiding unit (6) is provided in the drainage blind pipe network (5). The flow guiding unit (6) includes a bracket (61) fixed in the pipe and a central shaft (62) rotatably installed on the bracket (61). A flow guiding blade (63) is fixed at intervals on the central shaft (62); the primary waterproof layer (22) is fixed on the buffer layer (21) on the side away from the initial support (1); an adhesive layer is provided on one side surface of the secondary waterproof layer (23). The secondary waterproof layer (23) is fixedly bonded to the primary waterproof layer (22) on the side away from the initial support (1) by the adhesive layer, and the secondary waterproof layer (23) and the primary waterproof layer (22) are laid in a staggered manner to form a double-layer waterproof system. ​ 2. The double-layer waterproof structure of the super-large underground excavation cavern project according to claim 1, characterized in that: The buffer layer (21) is a non-woven geotextile, which is smoothly fixed to the base layer of the initial support (1) by nails with thermoplastic washers.

3. The double-layer waterproof structure of the super-large underground excavation cavern project according to claim 1, characterized in that: The primary waterproof layer (22) is a 1.5mm thick EVA waterproof board, and the secondary waterproof layer (23) is a 1.5mm thick self-adhesive HDPE self-adhesive film.

4. The double-layer waterproof structure of the super-large underground excavation cavern project according to claim 3, characterized in that: The primary waterproof layer (22) is fixed to the buffer layer (21) outside the initial support (1) by using a hot air gun to heat melt thermoplastic gaskets.

5. The double-layer waterproof structure for ultra-large underground tunnel projects according to claim 1, characterized in that: The drainage blind pipe network includes a circumferential drainage blind pipe (51), a longitudinal drainage blind pipe (52), and a transverse drainage blind pipe (53). The circumferential drainage blind pipe (51) is laid out circumferentially along the arc surface of the initial support (1). The longitudinal drainage blind pipe (52) is laid longitudinally along the low side walls on both sides of the tunnel. The transverse drainage blind pipe (53) is located below the invert arch. The longitudinal drainage blind pipe (52) is connected to the transverse drainage blind pipe and the circumferential drainage blind pipe by two T-joints. The output end of the transverse drainage blind pipe (53) is connected to the central drainage ditch (4).

6. The double-layer waterproof structure of the super-large underground excavation cavern project according to claim 5, characterized in that: The transverse drainage blind pipe (53) is provided with a flow guiding unit (6), and the flow guiding blades (63) are spaced apart at the two ends of the transverse drainage blind pipe (53).

7. The double-layer waterproof structure of the super-large underground excavation cavern project according to claim 5, characterized in that: Each drainage blind pipe is wrapped with geotextile to prevent pollutants from entering the perforated gaps of the blind pipe and causing blockage.

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