Tunnel lining waterproof structure suitable for corrosive environment and construction method of tunnel lining waterproof structure

Abstract

The invention provides a tunnel lining waterproof structure suitable for a corrosive environment and a construction method thereof.The tunnel lining waterproof structure comprises a primary supporting layer, a drainage layer, a water-resisting layer and a secondary lining layer which are sequentially arranged from outside to inside, the primary supporting layer is arranged on the surface of tunnel rock soil, and the drainage layer is fixed to the base face of the primary supporting layer through a fixing piece; the water-resisting layer comprises a first waterproof layer, a corrosion-resistant concrete layer and a second waterproof layer, and the corrosion-resistant concrete layer is arranged between the first waterproof layer and the second waterproof layer; the first waterproof layer is composed of a waterproof plate or a polyethylene film and a non-woven geotextile, and is arranged on the outer surface of the drainage layer; by means of the lining structure, the waterproof and drainage performance of the tunnel can be greatly improved, the corrosion resistance of the lining structure can be improved, and the structural strength and stability of the tunnel are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel lining construction, and in particular to a tunnel lining waterproof structure suitable for use in a corrosive environment and a construction method thereof. Background Art

[0002] Tunnels are an important type of transportation infrastructure. During tunnel construction, in order to enhance its structural stability and waterproof performance, a composite lining structure is usually adopted, including primary support and secondary lining. In order to prevent groundwater from leaking into the tunnel, a waterproof board is usually applied between the primary support and the secondary lining. However, when the tunnel passes through a stratum with high levels of corrosive substances such as sulfates and chlorides, these corrosive substances react physically and chemically with steel bars and concrete, causing damage and corrosion to the concrete lining, which in turn quickly reduces the overall durability of the tunnel structure, seriously affecting the construction and subsequent operational safety of the tunnel.

[0003] At present, the anti-corrosion property of tunnel lining mainly relies on adding corrosion resistant agents to the initial support shotcrete, laying waterproof boards to isolate water, and improving the density of concrete to reduce the permeability of harmful substances such as sulfate ions and chloride ions, thereby preventing them from corroding steel bars and concrete. However, when groundwater is fully developed, existing anti-corrosion technologies often cannot effectively solve the problem of groundwater carrying harmful substances such as sulfate ions and chloride ions into the tunnel. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems in the prior art and provide a tunnel lining waterproof structure and a construction method thereof which can effectively prevent erosion by corrosive substances and infiltration of groundwater.

[0005] To achieve the above object, the present invention proposes a tunnel lining waterproof structure suitable for use in a corrosive environment, comprising an initial support layer, a drainage layer, a water-proof layer and a secondary lining layer arranged in sequence from the outside to the inside:

[0006] The initial support layer is arranged on the tunnel rock and soil surface, and the drainage layer is fixed on the base surface of the initial support layer by means of fixing parts;

[0007] The waterproof layer includes a first waterproof layer, a corrosion-resistant concrete layer and a second waterproof layer, and the corrosion-resistant concrete layer is arranged between the first waterproof layer and the second waterproof layer;

[0008] The first waterproof layer is composed of a waterproof board or a polyethylene film and a non-woven geotextile, and is arranged on the outer surface of the drainage layer.

[0009] Furthermore, the fixing device is a threaded anchor rod, which is arranged in a plum blossom shape on the rock and soil surface of the tunnel, and passes through the initial support layer and the drainage layer in sequence. A metal ring and a nut are sleeved on the end close to the first waterproof layer, and are tightened and fixed by the nut; the end of the threaded anchor rod close to the first waterproof layer is also coated with sealing paste around the periphery to prevent groundwater from seeping into the tunnel lining through the gap.

[0010] Furthermore, the initial support layer includes a primary sprayed concrete layer, a steel frame support and a re-sprayed concrete layer arranged in sequence from the outside to the inside: the thickness of the primary sprayed concrete layer is greater than 60 mm, the thickness of the re-sprayed concrete layer is greater than 40 mm, the steel frame support is a grid steel frame, and the grid steel frame includes epoxy-coated steel bars and epoxy-coated steel plates. Threaded anchor rods penetrate the initial support layer, and the anchor rods, steel frames, steel bars, etc. are all coated with epoxy resin.

[0011] Furthermore, the thickness of the drainage layer is 15-20mm. The drainage layer is a drainage board with multiple boss structures, which has high-strength impact resistance and pressure resistance; one side of the drainage board with multiple bosses is in close contact with the surface of the initial support layer, and a three-dimensional drainage space is formed between the multiple bosses, so that it has excellent water collection and drainage capabilities, and can effectively collect tunnel seepage and quickly drain it; due to its light weight, it is easy for construction workers to install, and the load imposed on the initial lining of the tunnel is small, thereby avoiding damage to the tunnel structure.

[0012] The drainage board is fixed to the base surface of the initial support layer through the fixing member. The drainage layer can drain the corrosive groundwater around the tunnel, effectively avoiding the accumulation of groundwater, thereby reducing the corrosion of the tunnel structure.

[0013] Furthermore, the first waterproof layer is located between the drainage layer and the corrosion-resistant concrete layer. When the first waterproof layer is composed of a waterproof board, the waterproof board adopts an EVA waterproof membrane with a thickness of 1.5-2 mm. The waterproof board is hung on the outer surface of the drainage layer through a hot-melt pad. The hot-melt pad is sleeved on the anchor rod and arranged in a plum blossom shape on the outer surface of the drainage layer.

[0014] Furthermore, when the first waterproof layer is composed of a polyethylene film and a non-woven geotextile, the thickness of the polyethylene film is in the range of 0.5-1 mm; the density of the non-woven geotextile is in the range of 250-350 g / m 2 The polyethylene film is bonded to the surface of the drainage layer through a 0.2-0.5 mm thick adhesive layer; after the threaded anchor penetrates the drainage layer, it passes through the polyethylene film and the non-woven geotextile in turn, so that the drainage layer, polyethylene film and non-woven geotextile are fixed on the initial support layer through the threaded anchor.

[0015] Furthermore, the fixings (threaded anchor rods) are arranged in a plum blossom shape at intervals of 1m, the diameter of the fixings is 30mm, and the number of the fixings needs to be controlled within a certain range to ensure the fixing effect of the fixings on the drainage layer, hot-melt gasket or polyethylene film, and non-woven geotextile, and to avoid the risk of water seepage caused by too many fixings.

[0016] Furthermore, the second waterproof layer is located between the corrosion-resistant concrete layer and the secondary lining layer; the second waterproof layer adopts a polymer spray film waterproof material to form a spray-type waterproof structure; the thickness of the second waterproof layer ranges from 2 to 3 mm.

[0017] Furthermore, the wear-resistant concrete layer can be made by the method disclosed in Chinese patent CN112047684 B "A corrosion-resistant and anti-seepage concrete material and its preparation method", and the concrete has the advantages of good impermeability and corrosion resistance.

[0018] Furthermore, the polymer spray film waterproof material can be made by the method disclosed in Chinese patent CN113004468 B "A spray film waterproof material with excellent comprehensive performance", and the spray film waterproof material has the advantages of convenient construction, environmental protection, good mechanical properties and waterproof performance.

[0019] The waterproof layer composed of the first waterproof layer, the corrosion-resistant concrete layer and the second waterproof layer can effectively inhibit the flow of groundwater into the tunnel, thereby preventing the corrosion of the secondary lining steel bars by sulfate ions, chloride ions, etc. The corrosion-resistant concrete layer does not have steel bars, so it is not afraid of corrosion, and can effectively ensure the stability of the waterproof layer, avoid the formation of water seepage channels, and ensure the waterproof effect, durability and structural stability of the tunnel.

[0020] Furthermore, the thickness of the secondary lining layer ranges from 350 to 450 mm; the secondary lining layer uses low-heat concrete with a strength grade of C35-C40, and the steel bars use epoxy resin coated steel bars, which are tied or connected by sleeves. The use of low-heat concrete helps to avoid concrete cracks caused by the high hydration heat generated when high-grade concrete is poured. In addition, the use of low-water and shrinkage compensation technology is also an important strategy, that is, using low-heat cement instead of ordinary cement and adding a high ratio of mineral admixtures to further reduce the hydration heat, thereby avoiding the generation of concrete cracks and improving the concrete's impermeability. At the same time, in order to effectively protect the secondary lining steel bars, avoid welding methods to avoid damaging the epoxy coating.

[0021] The present invention also proposes a construction method for a tunnel lining waterproof structure suitable for use in a corrosive environment, comprising the following steps:

[0022] S1: A steel frame support structure coated with epoxy resin is set up on the rock and soil surface of the excavated tunnel, and a number of threaded anchor rods are arranged in a plum blossom shape, with one end of the thread facing away from the rock and soil surface. The surface of the anchor rods is coated with epoxy resin, and concrete is sprayed to form the initial support layer structure of the tunnel;

[0023] S2: installing a drainage board on the outer surface of the initial support layer so that one side of the drainage board having a plurality of bosses is in close contact with the surface of the initial support structure of the tunnel to form a drainage layer, and the threaded anchor rod passes through the drainage board;

[0024] S3: If the first waterproof layer is composed of a waterproof board, a hot-melt washer is inserted into the threaded anchor rod, and after adjusting the position, a sealing paste is applied, and then a metal ring and a nut are inserted into the anchor rod, and the nut is tightened to fix the hot-melt washer, and the waterproof board is hung through the hot-melt washer;

[0025] S4: If the first waterproof layer is composed of a polyethylene film and a non-woven geotextile, apply a rubber layer on the surface of the drainage board, lay the polyethylene film and the non-woven geotextile in sequence, the threaded anchor rod passes through the polyethylene film and the non-woven geotextile in sequence, and apply sealing paste around the threaded anchor rod, then insert a metal ring and a nut on the anchor rod, and tighten the nut to fix the drainage board, the polyethylene film and the non-woven geotextile.

[0026] S5: spraying corrosion-resistant concrete on the surface of the waterproof board or the non-woven geotextile to form a corrosion-resistant concrete layer;

[0027] S6: spraying a polymer spray film waterproof material on the surface of the corrosion-resistant concrete layer to form a second waterproof layer;

[0028] S7: applying concrete on the surface of the second waterproof layer to form a tunnel secondary lining layer structure, thereby completing the construction of the tunnel lining structure.

[0029] Furthermore, in step S1, the strength grade of the shotcrete is C25-C30; and the spacing between the threaded anchor rods is set to 1 m.

[0030] Compared with the prior art, the advantages of the present invention are:

[0031] 1. Compared with the problem of tunnel lining corrosion protection in the prior art that is difficult to adapt to strata containing high content of corrosive substances such as sulfates and chlorides due to reliance on corrosion resistant agents and methods of increasing concrete density, the present invention sequentially arranges an initial support layer, a drainage layer, a waterproof layer and a secondary lining layer, so that the formed lining structure effectively prevents the erosion of corrosive substances and the infiltration of groundwater through the waterproof layer, and utilizes the drainage layer to significantly improve the drainage capacity of the tunnel, avoiding the accumulation of corrosive groundwater in the surrounding area, thereby reducing the corrosion and penetration of groundwater to the tunnel lining, ensuring the integrity and safety of the tunnel structure, extending the service life of the tunnel and reducing maintenance costs.

[0032] 2. The present invention effectively inhibits the flow of groundwater into the tunnel through the tunnel water barrier structure composed of the first waterproof layer, the corrosion-resistant concrete layer and the second waterproof layer, thereby preventing the corrosion of sulfate ions, chloride ions and the like on the secondary lining.

[0033] 3. The present invention uses a corrosion-resistant concrete layer without steel bars, is not afraid of corrosion, can effectively ensure the stability of the waterproof layer, avoid the formation of water seepage channels, and ensure the waterproof effect, durability and structural stability of the tunnel.

[0034] 4. The present invention adopts a drainage board with multiple bosses as the drainage layer, and a three-dimensional drainage space is formed between the multiple bosses, so that it has excellent water collection and drainage capabilities, can effectively collect tunnel seepage and quickly drain it out, and effectively avoid groundwater accumulation by discharging corrosive groundwater around the tunnel, thereby reducing corrosion to the tunnel structure; in addition, due to its light weight, it is easy for construction workers to install, and the load imposed on the primary lining of the tunnel is small, thereby avoiding damage to the tunnel structure.

[0035] 5. The present invention not only improves the corrosion resistance and water-proof and drainage capabilities of the tunnel structure, but also enhances the durability of the structure, thereby hopefully reducing the cost of the later operation of the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of a tunnel lining waterproof structure suitable for use in a corrosive environment, as proposed in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of laying the first waterproof layer in Example 1 of the present invention;

[0038] Figure 3 This is a schematic diagram of laying the first waterproof layer in Example 2 of the present invention;

[0039] Figure 4 For the present invention, the fixing member layout plan 1. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further described below.

[0041] Example 1

[0042] This embodiment 1 proposes a tunnel lining waterproof structure suitable for use in a corrosive environment, such as Figure 1 As shown, the lining waterproof structure includes an initial support layer 1, a drainage layer 2, a waterproof layer, a secondary lining layer 6 and a fixing member 7 which are arranged in sequence from the outside to the inside, wherein the initial support layer 1 is arranged on the tunnel rock surface, and the drainage layer 2 is fixed to the base surface of the initial support layer 1 by the fixing member 7; the waterproof layer is arranged on the outer surface of the drainage layer, and the waterproof layer includes a first waterproof layer 3, a corrosion-resistant concrete layer 4 and a second waterproof layer 5, and the corrosion-resistant concrete layer 4 is arranged between the first waterproof layer 3 and the second waterproof layer 5; the secondary lining layer 6 is arranged on the outer surface of the second waterproof layer.

[0043] In Example 1, Figure 2 As shown, the fixing member 7 is a threaded anchor rod 11, which is arranged in a plum blossom shape on the surface of the tunnel rock soil, and passes through the initial support layer 1 and the drainage layer 2 in sequence. A metal ring 13 and a nut 16 are sleeved on the end close to the first waterproof layer 3, and are tightened and fixed by the nut 16; at the same time, the end of the threaded anchor rod 11 close to the first waterproof layer 3 is also coated with a sealing paste 12 around it to prevent groundwater from seeping into the tunnel lining from the gap. In addition, the diameter of the threaded anchor rod 11 is 30mm, and its arrangement is as follows Figure 4 As shown, the threaded anchor rods 11 are arranged in a quincuncial shape at intervals of 1 m.

[0044] In Example 1, the initial support layer 1 includes a primary sprayed concrete layer, a steel frame support, and a re-sprayed concrete layer arranged in sequence from the outside to the inside: wherein the thickness of the primary sprayed concrete layer is 80 mm, the thickness of the re-sprayed concrete layer is 50 mm, and the steel frame support is a grid steel frame, which includes epoxy-coated steel bars and epoxy-coated steel plates. The threaded anchor rod 11 penetrates the initial support layer 1, and at the same time, the anchor rod 11, the steel frame, the steel bars, etc. are all coated with epoxy resin.

[0045] In Example 1, the thickness of the drainage layer 2 is 20 mm. The drainage layer adopts a drainage board with multiple boss structures, which has high-strength impact resistance and pressure resistance. The side of the drainage board with multiple bosses is close to the surface of the initial support layer 1, and a three-dimensional drainage space is formed between the multiple bosses, so that it has excellent water collection and drainage capabilities, and can effectively collect tunnel seepage and quickly drain it out. Due to its light weight, it is easy for construction workers to install, and the load imposed on the initial lining of the tunnel is small, thereby avoiding damage to the tunnel structure.

[0046] The drainage board is fixed to the base surface of the initial support layer 1 through a threaded anchor rod 11. Through the drainage layer 2, corrosive groundwater around the tunnel can be discharged, effectively avoiding groundwater accumulation, thereby reducing corrosion to the tunnel structure.

[0047] In Example 1, the waterproof layer includes a first waterproof layer 3, a corrosion-resistant concrete layer 4, and a second waterproof layer 5, wherein the first waterproof layer 3 is arranged between the drainage layer 2 and the corrosion-resistant concrete layer 4. Figure 2 As shown, the first waterproof layer 3 is composed of a waterproof board 9, which adopts a 2mm thick EVA waterproof membrane and is hung on the outer surface of the drainage board through a hot-melt pad 10. The hot-melt pad 10 is sleeved on a threaded anchor rod 11 and arranged in a plum blossom shape on the outer surface of the drainage board.

[0048] In addition, the wear-resistant concrete layer 4 is made by the method disclosed in Chinese patent CN112047684 B "A Corrosion-Resistant and Seepage-Proofing Concrete Material and Preparation Method Thereof", and the concrete has the advantages of good impermeability and corrosion resistance.

[0049] The second waterproof layer 5 is located between the corrosion-resistant concrete layer 4 and the secondary lining layer 6; the thickness of the second waterproof layer 5 is 3 mm, and it adopts a single-component polymer spray waterproof material to form a spray-type waterproof structure. In this embodiment 1, the polymer spray waterproof material can be made by the method disclosed in Chinese patent CN113004468 B "A spray waterproof material with excellent comprehensive performance". The spray waterproof material has the advantages of convenient construction, environmental protection, good mechanical properties and waterproof performance.

[0050] The waterproof layer composed of the first waterproof layer 3, the corrosion-resistant concrete layer 4 and the second waterproof layer 5 can effectively inhibit the flow of groundwater into the tunnel, thereby preventing the corrosion of the secondary lining steel bars by sulfate ions, chloride ions, etc. Since the corrosion-resistant concrete layer does not have steel bars, it is not afraid of corrosion, and can effectively ensure the stability of the waterproof layer, avoid the formation of water seepage channels, and ensure the waterproof effect, durability and structural stability of the tunnel.

[0051] In this embodiment 1, the thickness of the secondary lining layer 6 is 400 mm; the secondary lining layer 6 adopts low-heat concrete with a strength grade of C40, and the steel bars adopt epoxy resin coated steel bars. At the same time, in order to effectively protect the secondary lining steel bars and avoid using welding methods to avoid damaging the epoxy coating, the steel bars are connected by binding or sleeves.

[0052] The specific construction method of the tunnel lining waterproof structure suitable for use in a corrosive environment proposed in the above-mentioned embodiment 1 is as follows:

[0053] S1: A steel frame support structure coated with epoxy resin is set up on the surface of the tunnel rock and soil after excavation, and a number of threaded anchor rods 11 are arranged in a plum blossom shape. The threaded end of the anchor rod is facing away from the rock and soil surface, and the surface of the anchor rod 11 is coated with epoxy resin, and concrete is sprayed to form the initial support layer 1 structure of the tunnel; wherein the strength grade of the sprayed concrete is C30;

[0054] S2: Pass the drain board with multiple bosses through the threaded anchor rod 11 and install it on the outer surface of the initial support layer 1, so that the side of the drain board with multiple bosses is close to the structural surface of the initial support layer 1 of the tunnel to form a drainage layer 2. At this time, the threaded anchor rod 11 penetrates the drain board;

[0055] S3: Use the waterproof board 9 as the first waterproof layer 3, insert the hot-melt gasket 10 on the threaded anchor rod 11, adjust the position, apply the sealing paste 12 around the end of the anchor rod 11 close to the hot-melt gasket 10, then insert the metal ring 13 and the nut 16 on the anchor rod 11, tighten the nut 16 to fix the hot-melt gasket 10, and finally hang the waterproof board 9 through the hot-melt gasket 10;

[0056] S4: spraying corrosion-resistant concrete on the surface of the waterproof board 9 to form a corrosion-resistant concrete layer 4;

[0057] S5: spraying a polymer spray film waterproof material on the surface of the corrosion-resistant concrete layer 4 to form a second waterproof layer 5;

[0058] S6: Concrete is applied on the surface of the second waterproof layer 5 to form a tunnel secondary lining layer structure 6, thereby completing the construction of the tunnel lining waterproof structure of Example 1.

[0059] Example 2

[0060] Example 2 proposes a tunnel lining waterproof structure suitable for use in a corrosive environment. The difference between Example 2 and Example 1 is that the structure of the first waterproof layer 3 is different.

[0061] In Example 2, the first waterproof layer 3 is composed of a polyethylene film 14 and a non-woven geotextile 15, wherein the thickness of the polyethylene film 14 is 1 mm; the density of the non-woven geotextile 15 is 300 g / m 2 The polyethylene film 14 is bonded to the surface of the drainage layer 2 through a 0.3 mm thick adhesive layer; Figure 3 As shown, after the threaded anchor rod 11 passes through the drainage layer 2, it passes through the polyethylene film 14 and the non-woven geotextile 15 in sequence, and fixes the drainage board, the polyethylene film 14 and the non-woven geotextile 15 on the base surface of the initial support layer 1.

[0062] The specific construction method of the tunnel lining waterproof structure suitable for use in a corrosive environment proposed in the above-mentioned embodiment 2 is as follows:

[0063] S1: A steel frame support structure coated with epoxy resin is set up on the surface of the tunnel rock and soil after excavation, and a number of threaded anchor rods 11 are arranged in a plum blossom shape. The threaded end of the anchor rod is facing away from the rock and soil surface, and the surface of the anchor rod 11 is coated with epoxy resin, and concrete is sprayed to form the initial support layer 1 structure of the tunnel; wherein the strength grade of the sprayed concrete is C30;

[0064] S2: Pass the drain board with multiple bosses through the threaded anchor rod 11 and install it on the outer surface of the initial support layer 1, so that the side of the drain board with multiple bosses is close to the structural surface of the initial support layer 1 of the tunnel to form a drainage layer 2. At this time, the threaded anchor rod 11 penetrates the drain board;

[0065] S3: Use the polyethylene film 14 and the non-woven geotextile 15 as the first waterproof layer 3, apply a rubber layer on the surface of the drainage board, lay the polyethylene film 14 and the non-woven geotextile 15 in sequence, pass the threaded anchor rod through the polyethylene film 14 and the non-woven geotextile 15 in sequence, and apply sealing paste 12 around the end of the threaded anchor rod 11 close to the first waterproof layer 3, then put the metal ring 13 and the nut 16 on the anchor rod 11, and tighten the nut 16 to fix the drainage board, the polyethylene film 14 and the non-woven geotextile 15.

[0066] S4: spraying corrosion-resistant concrete on the surface of the non-woven geotextile 15 to form a corrosion-resistant concrete layer 4;

[0067] S5: spraying a polymer spray film waterproof material on the surface of the corrosion-resistant concrete layer 4 to form a second waterproof layer 5;

[0068] S6: Concrete is applied on the surface of the second waterproof layer 5 to form a tunnel secondary lining layer structure 6, thereby completing the construction of the tunnel lining waterproof structure of Example 2.

[0069] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.

Claims

1. A tunnel lining waterproof structure suitable for use in a corrosive environment, characterized in that: It includes the initial support layer, drainage layer, waterproof layer and secondary lining layer which are arranged from the outside to the inside: The initial support layer is arranged on the tunnel rock and soil surface, and the drainage layer is fixed on the base surface of the initial support layer by means of fixing parts; The waterproof layer includes a first waterproof layer, a corrosion-resistant concrete layer and a second waterproof layer, and the corrosion-resistant concrete layer is arranged between the first waterproof layer and the second waterproof layer; The first waterproof layer is composed of a waterproof board or a polyethylene film and a non-woven geotextile, and is arranged on the outer surface of the drainage layer.

2. The tunnel lining waterproof structure suitable for use in a corrosive environment according to claim 1, characterized in that: The fixing device is a threaded anchor rod, which is arranged in a plum blossom shape on the tunnel rock surface, passes through the initial support layer and the drainage layer in sequence, and is sleeved with a metal ring and a nut at one end close to the first waterproof layer, and is tightened and fixed by the nut; the threaded anchor rod is also coated with sealing paste around one end close to the first waterproof layer.

3. The tunnel lining waterproof structure suitable for use in a corrosive environment according to claim 1, characterized in that: The initial support layer includes a primary sprayed concrete layer, a steel frame support and a re-sprayed concrete layer arranged in sequence from the outside to the inside: the thickness of the primary sprayed concrete layer is greater than 60 mm, the thickness of the re-sprayed concrete layer is greater than 40 mm, the steel frame support is a grid steel frame, and the grid steel frame includes epoxy-coated steel bars and epoxy-coated steel plates.

4. The tunnel lining waterproof structure suitable for use in a corrosive environment according to claim 1, characterized in that: The drainage layer is a drainage board with a plurality of boss structures. The side of the drainage board with the plurality of bosses is in close contact with the surface of the initial support layer. The drainage board is fixed to the base surface of the initial support layer through the fixing piece.

5. The tunnel lining waterproof structure suitable for use in a corrosive environment according to claim 2, characterized in that: When the first waterproof layer is composed of a waterproof board, the waterproof board adopts an EVA waterproof membrane with a thickness of 1.5-2 mm. The waterproof board is hung on the outer surface of the drainage layer through a hot-melt pad. The hot-melt pad is sleeved on the anchor rod and arranged in a plum blossom shape on the outer surface of the drainage layer.

6. The tunnel lining waterproof structure suitable for use in a corrosive environment according to claim 2, characterized in that: When the first waterproof layer is composed of a polyethylene film and a non-woven geotextile, the thickness of the polyethylene film is in the range of 0.5-1 mm; the density of the non-woven geotextile is in the range of 250-350 g / m 2 The polyethylene film is bonded to the surface of the drainage layer through a 0.2-0.5 mm thick adhesive layer; after the thread penetrates the drainage layer, it passes through the polyethylene film and the non-woven geotextile in turn, so that the drainage layer, polyethylene film and non-woven geotextile are fixed to the initial support layer through threaded anchor rods.

7. The tunnel lining waterproof structure suitable for use in a corrosive environment according to claim 1, characterized in that: The second waterproof layer is located between the corrosion-resistant concrete layer and the secondary lining layer; the second waterproof layer adopts a polymer spray film waterproof material to form a spray-type waterproof structure; the thickness of the second waterproof layer ranges from 2 to 3 mm.

8. The tunnel lining waterproof structure suitable for use in a corrosive environment according to claim 1, characterized in that: The thickness of the secondary lining layer ranges from 350 to 450 mm; the secondary lining layer adopts low-heat concrete with a strength grade of C35-C40; the steel bars adopt epoxy resin coated steel bars, and the steel bars are tied or connected by sleeves.

9. A construction method for a tunnel lining waterproof structure suitable for use in a corrosive environment as claimed in any one of claims 1 to 8, characterized in that: The steps include: S1: A steel frame support structure coated with epoxy resin is set up on the rock and soil surface of the excavated tunnel, and a number of threaded anchor rods are arranged in a plum blossom shape, with one end of the thread facing away from the rock and soil surface. The surface of the anchor rods is coated with epoxy resin, and concrete is sprayed to form the initial support layer structure of the tunnel; S2: installing a drainage board on the outer surface of the initial support layer so that one side of the drainage board having a plurality of bosses is in close contact with the surface of the initial support structure of the tunnel to form a drainage layer, and the threaded anchor rod passes through the drainage board; S3: If the first waterproof layer is composed of a waterproof board, a hot-melt washer is inserted into the threaded anchor rod, and after adjusting the position, a sealing paste is applied, and then a metal ring and a nut are inserted into the anchor rod, and the nut is tightened to fix the hot-melt washer, and the waterproof board is hung through the hot-melt washer; S4: If the first waterproof layer is composed of a polyethylene film and a non-woven geotextile, apply a rubber layer on the surface of the drainage board, lay the polyethylene film and the non-woven geotextile in sequence, the threaded anchor rod passes through the polyethylene film and the non-woven geotextile, and apply sealing paste around the threaded anchor rod, then insert a metal ring and a nut on the anchor rod, and tighten the nut to fix the drainage board, the polyethylene film and the non-woven geotextile layer. S5: spraying corrosion-resistant concrete on the surface of the waterproof board or the non-woven geotextile to form a corrosion-resistant concrete layer; S6: spraying a polymer spray film waterproof material on the surface of the corrosion-resistant concrete layer to form a second waterproof layer; S7: applying concrete on the surface of the second waterproof layer to form a tunnel secondary lining layer structure, thereby completing the construction of the tunnel lining structure.

10. The construction method of the tunnel lining waterproof structure suitable for use in a corrosive environment according to claim 9, characterized in that: In step S1, the strength grade of the shotcrete is C25-C30; and the spacing between the threaded anchor rods is set to 1 m.

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