A water conveyance tunnel lining structure capable of withstanding high internal and external water pressure and a construction method thereof

Abstract

The present invention provides a lining structure and construction method of a water conveyance tunnel that can withstand high internal and external water pressures. The structure includes an outer lining layer and an inner lining layer, wherein the inner lining layer is composed of a first lining, a high-strength force-transmitting water-permeable grille and a second lining; wherein the outer lining layer is arranged on the inner wall of the water conveyance tunnel; the first lining is arranged on the inner wall of the outer lining layer, and grouting is performed between the outer lining layer and the first lining to form a grouting layer, wherein the grouting layer and the outer lining layer form an integrated outer lining layer; the high-strength force-transmitting water-permeable grille is arranged on the inner wall of the first lining; and the second lining is arranged on the inner wall of the high-strength force-transmitting water-permeable grille. The lining structure of the water conveyance tunnel provided by the present invention strictly controls the excessive internal and external water pressures that the lining may withstand within an allowable range, avoids the risk of internal water seepage caused by tensile cracking of the lining, and eliminates the hidden danger of lining buckling deformation and instability caused by high external water pressure during the emptying period, thereby fundamentally solving the safety problem of the operation of the tunnel lining structure with high internal and external water pressures.

Description

Technical Field

[0001] The invention belongs to the field of water conservancy and hydropower, and relates to a water conveyance tunnel lining structure and a construction method, and specifically to a water conveyance tunnel lining structure and a construction method capable of withstanding high internal and external water pressures. Background Art

[0002] With the economic and social development of my country, the demand for electricity and the difference between peak and valley power consumption continue to increase, users' requirements for power supply quality continue to increase, and the large-scale development of random and intermittent new energy, as well as the demand for emergency backup and phase adjustment, have increased, which has put forward higher requirements for the development of hydropower stations. In recent years, pumped storage power stations, as power stations with high flexibility, have the functions of peak load adjustment, phase adjustment and backup of conventional power stations, and can also convert low-cost electricity into high-yield peak load electricity, thereby achieving effective utilization of energy.

[0003] The mechanism of hydroelectric power generation is to guide the water stored in the dam to the generator through tunnel pipes, such as Figure 1 As shown in the figure, the potential energy is converted into kinetic energy and then into electrical energy. Usually, this type of tunnel has the characteristics of high internal and external water pressure. Especially in the pumped storage power station project, the operating head has developed from 500m to 800m or even higher. The high internal and external water pressure water diversion tunnel is the key control "throat" project of the pumped storage power station. Its safe operation is related to the entire project construction and even the safety of life and property of the surrounding people. The water diversion tunnel is generally a thin-walled steel pipe attached inside the tunnel. The steel pipe must not only withstand the high internal water pressure during the filling period, the high external water pressure of the mountain water during the emptying period, and the deformation load of the surrounding rock. At present, when the traditional thin-walled steel pipe is emptied, the thin-walled steel pipe may be buckled and deformed due to the external water pressure of the mountain, which causes great trouble to the construction and safe operation of the pumped storage power station. Therefore, when designing the water diversion steel pipe, in addition to considering the internal water pressure, it is also necessary to consider the damage under the external water pressure during the emptying, and in order to prevent disasters such as landslides, it is also necessary to consider the structural type that avoids the infiltration of internal water. In order to improve the ability of water diversion tunnels to resist external water pressure, on the one hand, it is possible to consider increasing the ability to withstand external water pressure by influencing the design through the reinforcement height and spacing; on the other hand, the ability to withstand external pressure can be increased by increasing the thickness of the steel pipe, but this will result in an over-design relative to the internal pressure, which is uneconomical and wasteful.

[0004] Therefore, it is necessary to develop an economical and applicable lining structure type for the water diversion tunnel of a new pumped-storage power station that can withstand high internal and external water pressures based on the actual geological structure and structural mechanics mechanism, to achieve a structural design that can reasonably withstand internal and external water pressures, and to strictly control the excessive internal and external water pressures that the lining may withstand within the allowable range, to avoid the risk of internal water seepage caused by tensile cracking of the lining, and at the same time to eliminate the hidden danger of lining buckling, deformation and instability caused by high external water pressure during the discharge period, to fundamentally solve the safety problems of the operation of tunnel lining structures with high internal and external water pressures, and to provide scientific and technological support for breaking through the technical bottleneck of the pumped-storage power station industry and promoting the healthy and rapid development of the industry. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a water conveyance tunnel lining structure that can withstand high internal and external water pressures. The water conveyance tunnel lining structure strictly controls the excessive internal and external water pressures that the lining may withstand within an allowable range, avoiding the risk of internal water seepage caused by tensile cracking of the lining, and at the same time eliminating the hidden danger of lining buckling, deformation and instability caused by high external water pressure during the draining period, thereby fundamentally solving the safety problem of the operation of tunnel lining structures with high internal and external water pressures.

[0006] Another object of the present invention is to provide a construction method for the above-mentioned water conveyance tunnel lining structure that can withstand high internal and external water pressures.

[0007] In order to achieve the above-mentioned object, the present invention provides a water conveyance tunnel lining structure capable of withstanding high internal and external water pressure, comprising an outer lining layer and an inner lining layer, wherein the inner lining layer is composed of a first lining, a high-strength force-transmitting permeable grid and a second lining;

[0008] Wherein, the outer lining layer is arranged on the inner wall of the water conveyance tunnel;

[0009] The first inner lining is arranged on the inner wall of the outer lining layer, and grouting is performed between the outer lining layer and the first inner lining to form a grouting layer, wherein the grouting layer and the outer lining layer form an integrated outer lining layer;

[0010] The high-strength force-transmitting water-permeable grille is arranged on the inner wall of the first lining;

[0011] A second lining is arranged on the inner wall of the high-strength force-transmitting water-permeable grille.

[0012] Preferably, the outer lining layer is concrete or concrete segments.

[0013] Preferably, the first lining is a steel liner, a stiffening rib steel cylinder, a PVC pipe, a reinforced ring steel cylinder or a carbon fiber composite steel cylinder.

[0014] Preferably, the second lining is plain concrete, prestressed concrete, reinforced concrete, or concrete segments.

[0015] Preferably, the high-strength force-transmitting permeable grid is a fiberglass grid or a high-strength steel geogrid.

[0016] Preferably, the second lining is penetrated by a plurality of water valves.

[0017] Preferably, the inner wall of the second lining is provided with a roughness-reducing coating, a plurality of water valves are penetrated through the second lining and the roughness-reducing coating, and the roughness-reducing coating is an organic silicon coating or a fluorocarbon paint coating.

[0018] Preferably, the inner wall of the second lining is provided with an impermeable coating, and the impermeable coating is a polyurea elastomer coating.

[0019] The present invention also provides a construction method for the above-mentioned water conveyance tunnel lining structure capable of withstanding high internal and external water pressures, comprising the following steps:

[0020] 1) Excavate the tunnel by TBM or NATM blasting, and then drive anchors into the tunnel surrounding rock to reinforce the surrounding rock;

[0021] In the water conveyance tunnel project, anchor rods are first used to reinforce the surrounding rock of the water conveyance tunnel before construction, and then the subsequent lining structure construction is carried out. Driving the anchor rods deeper can play a role in reinforcing the surrounding rock of the tunnel.

[0022] 2) Cast or spray concrete, or install concrete segments on the surrounding rock to form an outer lining layer;

[0023] 3) installing a first inner lining, and then grouting between the first inner lining and the outer lining layer, and bonding the outer lining layer and the grouting layer to form an integrated outer lining;

[0024] 4) Lay high-strength force-transmitting water-permeable grid on the inner wall of the first lining;

[0025] 5) Lay the second lining on the inner wall of the high-strength force-transmitting permeable grille.

[0026] Furthermore, step 6) is added to set or prefabricate a plurality of water valves on the second liner;

[0027] Or, step 6) coating the inner wall of the inner lining layer with a roughness reduction coating, and then arranging or prefabricating a plurality of water valves on the second inner lining and the roughness reduction coating;

[0028] Or, step 6) coating an impermeable layer on the inner wall of the second lining.

[0029] The present invention is characterized in that:

[0030] After the first lining is installed, the present invention grouts between the outer lining layer and the first lining so that the outer lining layer and the grouting layer formed by the grouting are bonded into an integrated lining, thereby avoiding the generation of a gap between the first lining and the outer lining that causes the inner lining to move.

[0031] When the second lining is a well-cast concrete structure with a smooth surface and no potholes, it is possible to choose not to apply the roughness-reducing coating. When the inner lining layer is made of pipe segments or shotcrete, due to the low surface smoothness, there will be potholes, such as at the joints of the pipe segments, so a roughness-reducing coating is required to prevent the erosion of high-speed water flow from damaging the structure of the concrete or pipe segments.

[0032] In order to solve the buckling and deformation damage of the lining structure of the water conveyance tunnel caused by high internal and external water pressure, the existing technology needs to increase the wall thickness of the steel pipe to 40-80mm when using steel materials (steel pipes) as the inner lining, of which 40mm is located at a higher elevation (near the water storage dam end, where the external water pressure is lower), and 80mm is located at a lower elevation (near the generator end, where the external water pressure is higher), so that the steel material can withstand high internal and external water pressures. However, when the internal and external water pressures are unbalanced, the huge water pressure difference will still cause the steel material to buckle and deform, thereby affecting the safety and stability of the concrete structure of the inner lining layer. The present invention transmits the supporting function of the second lining to the steel pipe by setting a high-strength force-transmitting permeable grid to prevent the steel pipe from buckling and deforming, thereby reducing the thickness of the steel liner.

[0033] The present invention can further provide a water valve capable of bidirectional water flow in the second inner lining layer, so that when a water pressure difference is generated between the internal and external water pressures, the internal water can flow into the high-strength force-transmitting water-permeable grille through the water valve or flow from the high-strength force-transmitting water-permeable grille into the inner lining layer, thereby making the internal water pressure and the external water pressure of the second lining almost balanced, and avoiding a large pressure difference from damaging the concrete of the second lining.

[0034] In the structure of the present invention, the concrete supports the steel pipe through the high-strength force transmission grid, thereby preventing the steel pipe from deforming and buckling.

[0035] The beneficial effects of the present invention are:

[0036] The present invention provides a water conveyance tunnel lining structure that can withstand high internal and external water pressures. The water conveyance tunnel lining structure strictly controls the high internal and external water pressures that the lining may withstand within an allowable range, avoiding the risk of internal water leakage caused by tensile cracking of the lining, and eliminating the hidden danger of lining buckling deformation and instability caused by high external water pressure during the emptying period, fundamentally solving the safety problem of the operation of the tunnel lining structure with high internal and external water pressures. At the same time, the above structure can reduce the thickness of the inner lining steel pipe (from 40-80mm to 10-40mm), reduce the amount of steel used, reduce the cost of raw materials and transportation costs, and reduce the difficulty of construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the existing tunnel pipeline that guides water stored in the dam to the generator.

[0038] Figure 2A schematic diagram of a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures according to a preferred embodiment of the present invention.

[0039] Figure 3 A schematic diagram of a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures according to another preferred embodiment of the present invention.

[0040] Figure 4 A schematic diagram of a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures according to a third preferred embodiment of the present invention.

[0041] Figure 5 A schematic diagram of a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures according to a fourth preferred embodiment of the present invention.

[0042] Reference numerals

[0043] 1: outer lining layer; 2: first inner lining; 3: high-strength force-transmitting permeable grille; 4: second inner lining; 5: grouting layer; 6: surrounding rock; 7: anchor rod; 8: water valve; 9: roughness reduction coating; 10: anti-seepage coating. DETAILED DESCRIPTION

[0044] The embodiments of the present invention will be described in detail and comprehensively below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0045] Setting means that if it is poured concrete, the concrete can be opened up with tools after pouring and the water valve can be installed; prefabrication means that if the lining is prefabricated in a factory or other place other than the construction site, the water valve can be reserved in advance.

[0046] TBM is a full-section tunnel boring machine. Hard rock TBM uses the cutters on the rotating cutter disc to squeeze and shear the rocks. The bucket teeth on the rotating cutter disc pick up the slag, which falls into the main machine belt conveyor and is transported backwards. The slag is then transported out of the tunnel by a traction slag truck or a tunnel continuous belt conveyor.

[0047] NATM is the abbreviation of New Austrian Tunneling Method (NATM). NATM is a construction method based on tunnel engineering experience and rock mechanics theory, combining anchors and shotcrete as the main support means. After many practices and theoretical studies in some countries, it obtained patents and was officially named in the 1960s. NATM is indispensable in underground engineering, and NATM has almost become a basic method for building tunnels in areas with weak and broken surrounding rocks.

[0048] Since concrete of different grades has different compressive strength and different application scope in engineering, concrete of grades C25-C50 is mostly used in water conservancy projects, but concrete of different grades will also affect the project cost. In order to ensure the safety of the lining structure of the water diversion tunnel, different grades of concrete will also affect the lining structure during the lining construction when selecting concrete, and the construction method will also have an impact on the lining structure.

[0049] The raw materials used in the present invention are all commercially available commodities, and the processes not described in detail are all conventional processes in the art.

[0050] Example 1

[0051] This embodiment provides a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures, comprising an outer lining layer 1 and an inner lining layer;

[0052] The inner lining layer is composed of a first inner lining 2, a high-strength force-transmitting water-permeable grid 3 and a second inner lining 4;

[0053] Wherein, the outer lining layer 1 is arranged on the inner wall of the water conveyance tunnel;

[0054] The first inner lining 2 is arranged on the inner wall of the outer lining layer 1, and grouting is performed between the outer lining layer 1 and the first inner lining 2 to form a grouting layer 5, and the grouting layer and the outer lining layer form an integrated outer lining layer;

[0055] The high-strength force-transmitting water-permeable grille 3 is arranged on the inner wall of the first lining 2;

[0056] A second lining 4 is arranged on the inner wall of the high-strength force-transmitting water-permeable grille 3 .

[0057] In this embodiment, the outer lining layer uses sprayed concrete, the first lining uses a steel liner, the high-strength force-transmitting permeable grille uses a glass fiber reinforced plastic grille, and the second lining uses prestressed concrete.

[0058] The construction method is:

[0059] 1) A tunnel is excavated by TBM, and then anchor bolts 7 are driven into the tunnel surrounding rock 6 to reinforce the surrounding rock 6;

[0060] In water transfer tunnel projects, it is usually necessary to reinforce the surrounding rock of the water transfer tunnel with anchor rods before construction, and then carry out the subsequent lining structure construction.

[0061] 2) pouring or spraying concrete on the surrounding rock to form an outer lining layer 1;

[0062] 3) installing the first inner lining 2, and then grouting between the first inner lining 2 and the outer lining layer 1, so as to bond the outer lining layer 1 and the grouting layer 5 into an integrated outer lining;

[0063] 4) Laying a high-strength force-transmitting water-permeable grid 3 on the inner wall of the first lining 2;

[0064] 5) Lay the second lining 4 on the inner wall of the high-strength force-transmitting permeable grid 3 .

[0065] When the second lining uses prestressed concrete with excellent construction performance, it can achieve good anti-buckling deformation and anti-seepage effects.

[0066] When the structure of this embodiment is adopted, the second lining directly bears the internal water pressure, and the first lining does not directly bear the internal water pressure. At the same time, since the first lining is supported by the second lining through the high-strength force-transmitting water-permeable grille, the thickness of the first lining can be reduced to about 20mm-40mm when it is a steel liner.

[0067] Example 2

[0068] This embodiment provides a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures, comprising an outer lining layer 1 and an inner lining layer;

[0069] The inner lining layer is composed of a first inner lining 2, a high-strength force-transmitting water-permeable grid 3 and a second inner lining 4;

[0070] Wherein, the outer lining layer 1 is arranged on the inner wall of the water conveyance tunnel;

[0071] The first inner lining 2 is arranged on the inner wall of the outer lining layer 1, and grouting is performed between the outer lining layer 1 and the first inner lining 2 to form a grouting layer 5, and the grouting layer and the outer lining layer form an integrated outer lining layer;

[0072] The high-strength force-transmitting water-permeable grille 3 is arranged on the inner wall of the first lining 2;

[0073] A second lining 4 is provided on the inner wall of the high-strength force-transmitting water-permeable grille 3;

[0074] A plurality of water valves 8 are provided through the second lining 4 .

[0075] In this embodiment, the outer lining layer is a pasted pipe segment, the first lining is a reinforced steel cylinder ring, the high-strength force-transmitting permeable grille is a fiberglass grille, and the second lining is reinforced concrete.

[0076] The construction method is:

[0077] 1) Excavating a tunnel by NATM blasting, and then driving anchor bolts 7 into the tunnel surrounding rock 6 to reinforce the surrounding rock 6;

[0078] In water transfer tunnel projects, it is usually necessary to reinforce the surrounding rock of the water transfer tunnel with anchor rods before construction, and then carry out the subsequent lining structure construction.

[0079] 2) pouring or spraying concrete on the surrounding rock to form an outer lining layer 1;

[0080] 3) installing the first inner lining 2, and then grouting between the first inner lining 2 and the outer lining layer 1, so as to bond the outer lining layer 1 and the grouting layer 5 into an integrated outer lining;

[0081] 4) Laying a high-strength force-transmitting water-permeable grid 3 on the inner wall of the first lining 2;

[0082] 5) Laying the second lining 4 on the inner wall of the high-strength force-transmitting water-permeable grille 3;

[0083] 6) Multiple water valves 8 are provided on the second lining 4

[0084] In this embodiment, when the first liner is made of steel cylinder, the steel cylinder can be prevented from buckling because it is supported by the second liner through the high-strength force-transmitting water-permeable grille; at the same time, water forms a dynamic balance in the high-strength force-transmitting water-permeable grille and the second liner, that is, when the second liner is in a water-filled state, the water inside the second liner flows into the water-permeable grille to protect the second liner from being damaged by the internal water pressure; when the second liner is not in a water-filled state, the water in the high-strength force-transmitting water-permeable grille flows into the liner, and the high-strength force-transmitting water-permeable grille does not have to be in a water storage state all the time. This arrangement allows the second liner to be protected by water pressure balance when it is made of a material with lower strength such as plain concrete.

[0085] The number of water valves is designed according to the actual stress conditions of the pipeline. Generally, they are set in places where the pipeline is subjected to greater tensile stress, i.e., at the top and bottom of the lining.

[0086] When the structure of this embodiment is adopted, the safety of the second liner is improved due to the water pressure balance on both sides of the second liner, and the thickness of the steel cylinder supported by the second liner through the high-strength force-transmitting permeable grille can be reduced to 10-30mm.

[0087] Example 3

[0088] This embodiment provides a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures, comprising an outer lining layer 1 and an inner lining layer;

[0089] The inner lining layer is composed of a first inner lining 2, a high-strength force-transmitting water-permeable grid 3 and a second inner lining 4;

[0090] Wherein, the outer lining layer 1 is arranged on the inner wall of the water conveyance tunnel;

[0091] The first inner lining 2 is arranged on the inner wall of the outer lining layer 1, and grouting is performed between the outer lining layer 1 and the first inner lining 2 to form a grouting layer 5, and the grouting layer and the outer lining layer form an integrated outer lining layer;

[0092] The high-strength force-transmitting water-permeable grille 3 is arranged on the inner wall of the first lining 2;

[0093] A second lining 4 is arranged on the inner wall of the high-strength force-transmitting water-permeable grille 3 .

[0094] The inner wall of the second lining is provided with a roughness reduction coating 9, and a plurality of water valves 8 are provided through the second lining 4 and the roughness reduction coating 9.

[0095] In this embodiment, the outer lining layer is sprayed concrete, the first inner lining layer is a stiffening rib steel tube, the high-strength force-transmitting permeable grid is a high-strength steel-plastic geogrid, the second inner lining is plain concrete, and the roughness-reducing coating is an organic silicon coating.

[0096] The construction method is:

[0097] 1) Excavating a tunnel by NATM blasting, and then driving anchor bolts 7 into the tunnel surrounding rock 6 to reinforce the surrounding rock 6;

[0098] In water transfer tunnel projects, it is usually necessary to reinforce the surrounding rock of the water transfer tunnel with anchor rods before construction, and then carry out the subsequent lining structure construction.

[0099] 2) pouring or spraying concrete on the surrounding rock to form an outer lining layer 1;

[0100] 3) installing the first inner lining 2, and then grouting between the first inner lining 2 and the outer lining layer 1, so as to bond the outer lining layer 1 and the grouting layer 5 into an integrated outer lining;

[0101] 4) Laying a high-strength force-transmitting water-permeable grid 3 on the inner wall of the first lining 2;

[0102] 5) Laying the second lining 4 on the inner wall of the high-strength force-transmitting water-permeable grille 3;

[0103] 6) A roughness-reducing coating 9 is coated on the inner wall of the inner lining layer, and then a plurality of water valves 8 are prefabricated on the second inner lining layer and the roughness-reducing coating.

[0104] Compared with Example 2, this embodiment adds a roughness reduction coating to solve the problem that the inner wall of the second inner lining is not smooth when using shotcrete or laying concrete segments. The rough inner wall will block the water flow, and the water flow pressure at the blocked point will increase, causing scouring and damage to the second inner lining, affecting the safety of the entire lining structure. At the same time, similar to Example 2, when the first inner lining is a steel cylinder, this embodiment can reduce the thickness of the steel cylinder to 10-30mm.

[0105] Example 4

[0106] This embodiment provides a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures, comprising an outer lining layer 1 and an inner lining layer;

[0107] The inner lining layer is composed of a first inner lining 2, a high-strength force-transmitting water-permeable grid 3 and a second inner lining 4;

[0108] Wherein, the outer lining layer 1 is arranged on the inner wall of the water conveyance tunnel;

[0109] The first inner lining 2 is arranged on the inner wall of the outer lining layer 1, and grouting is performed between the outer lining layer 1 and the first inner lining 2 to form a grouting layer 5, and the grouting layer and the outer lining layer form an integrated outer lining layer;

[0110] The high-strength force-transmitting water-permeable grille 3 is arranged on the inner wall of the first lining 2;

[0111] A second lining 4 is arranged on the inner wall of the high-strength force-transmitting water-permeable grille 3 .

[0112] An impermeable coating 10 is provided on the inner wall of the second lining 4 .

[0113] In this embodiment, the outer lining layer is sprayed concrete, the first inner lining layer is a steel liner, the high-strength force-transmitting permeable grille is a fiberglass grille, the second inner lining is prestressed concrete, and the anti-seepage coating is a polyurea elastomer coating.

[0114] The construction method is:

[0115] 1) Excavating a tunnel by NATM blasting, and then driving anchor bolts 7 into the tunnel surrounding rock 6 to reinforce the surrounding rock 6;

[0116] In water transfer tunnel projects, it is usually necessary to reinforce the surrounding rock of the water transfer tunnel with anchor rods before construction, and then carry out the subsequent lining structure construction.

[0117] 2) pouring or spraying concrete on the surrounding rock to form an outer lining layer 1;

[0118] 3) installing the first inner lining 2, and then grouting between the first inner lining 2 and the outer lining layer 1, so as to bond the outer lining layer 1 and the grouting layer 5 into an integrated outer lining;

[0119] 4) Laying a high-strength force-transmitting water-permeable grid 3 on the inner wall of the first lining 2;

[0120] 5) Laying the second lining 4 on the inner wall of the high-strength force-transmitting water-permeable grille 3;

[0121] 6) Coating an impermeable layer on the inner wall of the second lining.

[0122] When the structure of this embodiment is adopted, the second lining directly bears the internal water pressure, and no water valve is set. The first lining does not directly bear the internal water pressure. At the same time, since the steel cylinder is supported by the second lining through the high-strength force-transmitting and permeable grille, the thickness of the first lining can be reduced to about 1mm-20mm when it is a steel lining.

[0123] It can be seen from the above embodiments that the present invention provides a water conveyance tunnel lining structure that can withstand high internal and external water pressures. The water conveyance tunnel lining structure strictly controls the excessive internal and external water pressures that the lining may withstand within an allowable range, thereby avoiding the risk of internal water seepage caused by tensile cracking of the lining, and at the same time eliminating the hidden danger of lining buckling, deformation and instability caused by high external water pressure during the draining period, thereby fundamentally solving the safety problem of the operation of tunnel lining structures with high internal and external water pressures.

Claims

1. A water conveyance tunnel lining structure capable of withstanding high internal and external water pressures, comprising an outer lining layer and an inner lining layer, characterized in that: The inner lining layer is composed of a first inner lining, a high-strength force-transmitting water-permeable grid and a second inner lining; Wherein, the outer lining layer is arranged on the inner wall of the water conveyance tunnel; The first inner lining is arranged on the inner wall of the outer lining layer, and grouting is performed between the outer lining layer and the first inner lining to form a grouting layer, wherein the grouting layer and the outer lining layer form an integrated outer lining layer; The high-strength force-transmitting water-permeable grille is arranged on the inner wall of the first lining; A second lining is arranged on the inner wall of the high-strength force-transmitting water-permeable grille; a plurality of water valves are passed through the second lining; The first lining is a steel liner, a stiffening rib steel cylinder, a reinforced ring steel cylinder or a carbon fiber composite steel cylinder; The second lining is plain concrete, reinforced concrete, or concrete segments.

2. The water conveyance tunnel lining structure capable of withstanding high internal and external water pressures as claimed in claim 1, characterized in that: The outer lining layer is concrete or concrete segments.

3. The water conveyance tunnel lining structure capable of withstanding high internal and external water pressures as claimed in claim 1, characterized in that: The high-strength force-transmitting permeable grid is a glass fiber reinforced plastic grid or a high-strength steel plastic geogrid.

4. The water conveyance tunnel lining structure capable of withstanding high internal and external water pressures according to any one of claims 1 to 3, characterized in that: The inner wall of the second lining is provided with a roughness reduction coating, and a plurality of water valves are arranged through the second lining and the roughness reduction coating. The roughness reduction coating is an organic silicon coating or a fluorocarbon paint.

5. The construction method of a water conveyance tunnel lining structure capable of withstanding high internal and external water pressures according to any one of claims 1 to 3, characterized in that: The following steps are involved: 1) Dig out the tunnel by TBM or NATM blasting, and then drive anchors into the tunnel surrounding rock to reinforce the surrounding rock; 2) Cast or spray concrete on the surrounding rock, or install concrete segments to form an outer lining layer; 3) installing a first inner lining, and then grouting between the first inner lining and the outer lining layer, so as to bond the outer lining layer and the grouting layer into an integrated outer lining; 4) Lay high-strength force-transmitting water-permeable grid on the inner wall of the first lining; 5) Lay the second lining on the inner wall of the high-strength force-transmitting permeable grille; 6) A plurality of water valves are arranged or prefabricated in the second lining.

6. The construction method of the water conveyance tunnel lining structure capable of withstanding high internal and external water pressures as claimed in claim 5, characterized in that: Step 6) coating the inner wall of the second liner with a roughness reduction coating, and then arranging or prefabricating a plurality of water valves on the second liner and the roughness reduction coating.

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