High-pressure water channel prefabricated reinforced concrete sandwich steel plate lining structure and construction method thereof

Abstract

The application discloses a prefabricated reinforced concrete sandwich steel plate lining structure of a high-pressure water channel and a construction method thereof. The prefabricated reinforced concrete sandwich steel plate lining structure of the high-pressure water channel comprises a steel plate, a reinforcing steel bar, a reinforced concrete cylinder shell, a gasket, surrounding rock, a horn, a reserved groove, a horn reserved hole, a water passage and a ring-shaped water hole. The gasket is a semi-cavity body made of elastic material and is arranged on the outer side of the steel plate and the reinforced concrete cylinder shell. The gasket can be filled with water to expand under the environment of high internal water pressure, so that the reinforced concrete cylinder shells on both sides are tightly pressed. The horn and the steel plate are in an integral structure and are used for hoisting and transporting the prefabricated lining. The construction method comprises the following steps: manufacturing key components, assembling before pouring, pouring the reinforced concrete cylinder shell, installing the gasket and grouting. The application can realize the purpose of quickly and safely lining the structures such as the vertical shaft of the pumped storage power station high-pressure water channel, guarantees the safety of the high-pressure water channel in the whole life cycle and accelerates the construction speed of the high-pressure water channel.

Description

TECHNICAL FIELD

[0001] The present application relates to a prefabricated steel reinforced concrete sandwich steel plate lining structure of high pressure water channel and a construction method thereof, in particular to the rapid construction of a hydraulic tunnel lining under the operation environment of high internal water pressure of a vertical shaft of a pumped storage power station. BACKGROUND

[0002] At present, the design type of the upper reservoir from the intake of the pumped storage power station mainly includes the upper tunnel, inclined (vertical) shaft, middle tunnel, inclined (vertical) shaft and lower tunnel, which is difficult to be quickly developed in the construction process due to the limitation of topographic conditions, construction organization conditions and the like, especially the limitation of access conditions, which leads to the fact that some projects cannot be quickly constructed. How to optimize the original design scheme and ensure the construction speed of the pumped storage power station is a technical problem to be solved. Therefore, a prefabricated steel reinforced concrete sandwich steel plate lining structure of high pressure water channel and a construction method thereof are proposed, which can optimize the arrangement type of the original design of the upper tunnel, inclined (vertical) shaft, middle tunnel, inclined (vertical) shaft and lower tunnel into the type of the upper tunnel, vertical shaft and lower tunnel. By prefabricating a high pressure water channel steel reinforced concrete sandwich steel plate lining structure, the structure is hoisted from the top of the hole into the excavated vertical shaft, and through the method of post-contact grouting, the proposed high pressure water channel steel reinforced concrete sandwich steel plate lining structure is in close contact with the surrounding rock, so as to achieve the purpose of jointly bearing the load of the high pressure water channel under different working conditions, which can effectively increase the construction speed and safety of the vertical shaft structure of the pumped storage high pressure water channel. SUMMARY

[0003] The present application aims to provide a prefabricated steel reinforced concrete sandwich steel plate lining structure of high pressure water channel and a construction method thereof, which can realize the purpose of rapid and safe lining of the vertical shaft structure of the pumped storage power station high pressure water channel, ensure the safety of the high pressure water channel during the entire life cycle, and speed up the construction speed of the high pressure water channel, so as to solve the problems proposed in the above background technology.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0005] The application relates to a prefabricated steel reinforced concrete sandwich steel plate lining structure of a high-pressure water channel, characterized in that the lining structure comprises a steel plate, a steel bar, a steel reinforced concrete cylinder shell, a gasket, surrounding rock, a horn on the steel plate and a reserved groove, a horn reserved hole on the gasket, a water passing channel and a ring-shaped water passing hole; the steel plate is arranged at the middle part of the steel reinforced concrete cylinder shell, and one side of the steel plate is provided with a horn; the horn passes through the horn reserved hole on the gasket and is hidden in the reserved groove of the steel plate of another section of the prefabricated steel reinforced concrete sandwich steel plate lining structure during installation of the lining structure, and the size of the reserved groove meets the requirement of the horn entering; the steel bar comprises longitudinal steel bars and ring-shaped steel bars and is arranged in the steel reinforced concrete cylinder shells on both sides of the steel plate; the gasket is arranged on one side of the steel plate and the steel reinforced concrete cylinder shell, the gasket is provided with a horn reserved hole, the size of the horn reserved hole meets the requirement of the horn passing through, the gasket is provided with the water passing channel and the ring-shaped water passing hole, the ring-shaped water passing hole is distributed along 360 degrees in the ring direction in the gasket and is distributed along the radial direction in the table fold line segment, the water passing channel is distributed along the ring direction of the gasket at equal intervals with an interval of 90 degrees and is communicated with the ring-shaped water passing hole; the gasket is made of elastic material and can produce elastic deformation under pressure; after the prefabricated lining structure is installed, the water channel is filled with water, the water body in the water channel fills the ring-shaped water passing hole through the water passing channel, the ring-shaped water passing hole can expand under the water body pressure and tightly extrude the steel reinforced concrete cylinder shell; the surrounding rock is connected with the outer side of the steel reinforced concrete cylinder shell through a grouting layer.

[0006] Further, the inner and outer surfaces of the steel plate can be smooth curved surfaces, and a certain thickness of steel ribs can be arranged at equal intervals on the inner and outer surfaces to increase the friction and engagement force between the steel plate and the steel reinforced concrete cylinder shell, prevent the steel plate from falling off the steel reinforced concrete cylinder shell during installation and lifting and enable the steel plate and the steel reinforced concrete cylinder shell to jointly bear during operation of the high-pressure water channel.

[0007] Further, the thickness of the steel plate can be determined according to the bearing condition of the prefabricated steel reinforced concrete sandwich steel plate lining structure.

[0008] Further, the horn and the steel plate are an integral structure and can be formed by welding or cutting reservation; the reserved groove is cut on the steel plate.

[0009] Further, the upper and lower side surfaces of the steel reinforced concrete cylinder shell are corresponding concave-convex surfaces and are consistent with the shape of the gasket, so that the steel reinforced concrete cylinder shell and the gasket can be mutually attached, and the steel reinforced concrete cylinder shell is generated by using a regular shape mold during pouring and prefabrication.

[0010] Further, the longitudinal steel bars and the ring-shaped steel bars are distributed in the steel reinforced concrete cylinder shell, and the diameters and spacing arrangements of the steel bars can be determined according to the bearing load.

[0011] Further, the shape of the gasket is consistent with the shape of the upper and lower side surfaces of the steel reinforced concrete cylinder shell, so that the gasket and the steel reinforced concrete cylinder shell can be mutually attached.

[0012] The application further provides a construction method of the prefabricated steel reinforced concrete sandwich steel plate lining structure of a high-pressure water channel.

[0013] Step 1: prefabricating key components, comprising:

[0014] a) erecting a shed structure in a prefabrication factory, and respectively arranging a prefabrication room, a steel plate and steel bar processing room, a curing room and a finished product room. According to the size requirements such as the diameter and thickness of the shaft lining, the steel plate is formed by underground material, coiling and welding in the prefabrication factory, the steel ribs are welded to the inner and outer surfaces of the steel plate, the whole structure is formed by welding or cutting the reserved ear of the cow and the steel plate, and the reserved groove is cut on the steel plate;

[0015] b) according to the diameter of the shaft lining, the corresponding length of the longitudinal steel bars and the circumferential steel bars are processed in advance in the steel bar processing factory. The surface of the steel bars should be treated clean during processing, the size of various steel bars should meet the size of the drawing and meet the specification requirements, and the processed steel bars are numbered;

[0016] c) the required gaskets are processed in advance according to the design hole diameter. The gaskets are made of elastic material and have a water passage and a ring-shaped water hole;

[0017] Step 2: assembly and preparation before pouring:

[0018] a) according to the design hole diameter, the steel reinforced concrete forming mold is prepared in advance. In order to ensure that the upper and lower side surfaces of the cylinder are corresponding concave-convex surfaces, are consistent with the shape of the gasket and can be mutually attached, the upper and lower side molds should also use custom regular shape molds; the above molds are cleaned and coated with a release agent;

[0019] b) erecting the forming mold by erecting the forming mold and the inner and outer support bent frames in the prefabrication site, fixing the prefabricated steel plate at the corresponding position of the mold, and fixing the prefabricated longitudinal steel bars and circumferential steel bars after binding them to the corresponding positions on both sides of the steel plate;

[0020] c) after the positioning and assembly of the steel plate and the steel bars are completed, in order to ensure that the thickness of the protective layer meets the requirements, 3cm thick cushion blocks are arranged on the inner and outer steel bars, in order to prevent the leakage of concrete during the pouring process and affect the forming quality, the interface of the mold is fixed firmly by bolts, and paper adhesive tape is pasted between the joint position and the forming mold.

[0021] Step 3: pouring concrete and removing and curing the mold:

[0022] a) pouring the steel reinforced concrete cylinder shell: the concrete is supplied by a mixing system, transported to the construction site by a concrete tank truck, and unloaded into the mold by a pump. The concrete pouring requires to be completed at one time, in order to ensure that the concrete is poured densely, the insertion type vibrating rod is used, and the rod is inserted quickly and taken out slowly, and the surface is observed to see if there are any bubbles overflowing;

[0023] b) After the concrete is vibrated and compacted, the upper side should be leveled to ensure smooth docking of the cylinder shell;

[0024] c) After the concrete is poured, it should be watered and maintained in time to ensure the quality of the concrete surface forming and no cracking phenomenon;

[0025] d) After the standard strength is maintained, the formwork is removed in order, and the outer surface of the cylinder shell is cleaned to make it smooth and smooth. It is strictly forbidden to hammer the mold with heavy objects; at the same time, the mold surface should be cleaned in time, and the deformed position of the mold should be repaired; the surface temperature and the ambient temperature should not differ by more than 20℃ when the formwork is removed.

[0026] Step 4: Bonding gasket: Bond the prefabricated gasket with the top surface of the steel plate and reinforced concrete cylinder shell with high-strength adhesive. To ensure the quality of bonding, a bonding test should be conducted in advance to select the appropriate high-strength adhesive;

[0027] Step 5: Pile protection: After the above steps are completed, the prefabricated reinforced concrete cylinder shell is stored in the finished product room and stacked according to the hoisting sequence and pouring sequence.

[0028] Step 6: On-site installation and grouting:

[0029] a) A prefabricated steel reinforced concrete sandwich steel plate lining structure for high-pressure waterways is hoisted into a transport vehicle and transported to the shaft wellhead platform. A 100t crane is used in the shaft, and manual hoist is used to assist the hoisting of the finished product to the wellhead platform, and the shaft hoisting system is used to slowly hoist it into the excavated shaft; ensure that the various hoist connections are reliable during hoisting, and protect the cylinder structure from bumps to ensure the appearance quality. Before hoisting, a test hoisting should be conducted. After the test hoisting is normal, the formal hoisting can be carried out.

[0030] b) When the prefabricated lining structure approaches the working surface, the installation workers should use the rope to assist the positioning to ensure that the lining structure has consistent elevation and consistent gap. After installation, the flatness should be detected.

[0031] c) A φ25mm contact grouting iron pipe is pre-embedded between the lining structure and the surrounding rock. The iron pipe is led to the outside of the lining structure. After the hoisting is completed, the end is sealed with a formwork, and a thick slurry with a water-cement ratio of 0.5:1 and a grouting pressure of 0.5MPa is used to fill between the lining structure and the surrounding rock, ensuring that the lining structure and the surrounding rock are in close contact and jointly bear the load during the high-pressure waterway process.

[0032] Compared with the prior art, the present application has the advantages that the present application is a prefabricated structure, simple in structure, reasonable in design, efficient in transportation and construction, can realize rapid and safe construction of lining structure in a high internal water pressure environment without affecting the entire life cycle of the high pressure water channel, and can meet the needs of different types of projects by adjusting the thickness of the steel plate, the diameter and spacing arrangement of the steel bars, and giving different support force values. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a lining structure diagram in the present application.

[0034] Figure 2 It is a fixed relative position diagram of the steel plate and the steel bars before concrete pouring in the present application.

[0035] Figure 3 It is an upper structure diagram of the steel plate and the reinforced concrete cylinder shell in the present application.

[0036] Figure 4 It is an internal structure diagram of the gasket in the present application.

[0037] Figure 5 It is a cross section diagram of the prefabricated lining structure in the present application.

[0038] Figure 6 It is an example diagram of the prefabricated lining structure in the present application.

[0039] Among them, 1-steel plate; 2-steel bar; 3-reinforced concrete cylinder shell; 4-gasket; 5-surrounding rock; 101-ox ear; 102-reserved groove; 201-longitudinal steel bar; 202-circumferential steel bar; 401-ox ear reserved hole; 402-water passage; 403-annular water hole. DETAILED DESCRIPTION

[0040] The technical solutions of the present application will be described clearly and completely below by combining the embodiments of the present application and the drawings. It should be understood that the embodiments described below are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained without creative labor are within the scope of protection of the present application.

[0041] As shown in Figures 1-6 , a prefabricated reinforced concrete sandwich steel plate lining structure for a high pressure water channel of the present application comprises a steel plate 1, a steel bar 2, a reinforced concrete cylinder shell 3, a gasket 4, surrounding rock 5, an ox ear 101, a reserved groove 102, a longitudinal steel bar 201, a circumferential steel bar 202, an ox ear reserved hole 401, a water passage 402, and an annular water hole 403.

[0042] As shown in Figure 1 , Figure 2 ,Figure 3 and Figure 5 As shown in the drawings, the steel plate 1 is arranged at the middle part of the reinforced concrete cylinder 3, and one side of the steel plate 1 is provided with a horn 101; the horn 101 passes through a horn reserved hole 401 on the gasket 4, and is hidden in a reserved groove 102 of the steel plate 1 of another section of the prefabricated reinforced concrete sandwich steel plate lining structure during installation of the lining structure, the size of the reserved groove 102 meets the requirement of the horn 101 entering; the inner and outer surfaces of the steel plate 1 can be smooth curved surfaces, in order to increase the friction and engagement force between the steel plate 1 and the reinforced concrete cylinder 3, the inner and outer surfaces can be provided with steel ribs at equal intervals and a certain thickness, so as to prevent the steel plate 1 from falling off the reinforced concrete cylinder 3 during installation and hoisting, and the steel plate 1 and the reinforced concrete cylinder 3 jointly bear during operation of the high-pressure water channel; the thickness of the steel plate 1 can be determined according to the bearing condition of the prefabricated reinforced concrete sandwich steel plate lining structure; the horn 101 and the steel plate 1 are an integral structure, and can be formed by welding or cutting reservation; the reserved groove 102 is cut on the steel plate 1.

[0043] As shown in the drawings, Figure 1 , Figure 2 , Figure 3 and Figure 5 The steel bars 2 have longitudinal steel bars 201 and circumferential steel bars 202, which are arranged in the reinforced concrete cylinder 3 on both sides of the steel plate 1.

[0044] As shown in the drawings, Figure 1 , Figure 3 , Figure 5 and Figure 6 The upper and lower surfaces of the reinforced concrete cylinder 3 are corresponding concave-convex surfaces, which are consistent with the shape of the gasket 4 and can be attached to each other, and are generated by using a regular-shaped template during pouring and prefabrication of the reinforced concrete cylinder 3; the longitudinal steel bars 201 and the circumferential steel bars 202 are distributed in the reinforced concrete cylinder 3, and the diameter and spacing of the steel bars can be determined according to the bearing load.

[0045] As shown in the drawings, Figure 1 , Figure 4 , Figure 5 and Figure 6As shown, the gasket 4 is disposed on one side of the steel plate 1 and the reinforced concrete shell 3. The gasket 4 is provided with a bull's ear pre-reserved hole 401. The size of the bull's ear pre-reserved hole 401 meets the requirement that the bull's ear 101 passes through. The gasket 4 is provided with a water passage 402 and an annular water passage hole 403. The annular water passage hole 403 is distributed in a 360° range along the inner circumference of the gasket and in a radial distribution on the broken line segment of the platform. The water passage 402 is distributed at equal intervals of 90° along the circumference of the gasket 4 and is connected to the annular water passage hole 403. The gasket 4 is an elastic material and can produce a certain elastic deformation under pressure. The shape of the gasket 4 is consistent with the shape of the upper and lower surfaces of the reinforced concrete shell 3 and can fit together. After the prefabricated lining structure is installed, when the high-pressure water channel is filled with water, the water in the water channel fills the annular water passage hole 403 through the water passage 402. The annular water passage hole 403 can expand under the water pressure and tightly compress the reinforced concrete shell 3.

[0046] like Figure 6 As shown, the surrounding rock 5 is connected to the outside of the reinforced concrete shell 3 through a grouting layer.

[0047] The present invention discloses a construction method for a precast reinforced concrete sandwich steel plate lining structure for high-pressure waterways, comprising the following construction steps:

[0048] Step 1: Prefabricate key components, including:

[0049] a) A prefabrication plant is constructed with a shed structure, including a prefabrication room, a steel plate and rebar processing room, a curing room, and a finished product room. Based on the dimensional requirements of the shaft lining diameter and thickness, materials are prepared, rolled, and welded into steel plates at the prefabrication plant. Steel ribs are welded to the inner and outer surfaces of the steel plates, and the ribs are pre-formed into the steel plates through welding or cutting to create an integral structure. Pre-cut grooves are also created on the steel plates.

[0050] b) Based on the diameter of the shaft lining, longitudinal and circumferential reinforcing bars of the corresponding length should be pre-processed at the steel bar processing plant. During processing, the surface of the reinforcing bars should be cleaned, and the dimensions of various reinforcing bars should conform to the dimensions in the drawings and meet the requirements of the specifications. The processed reinforcing bars should be numbered.

[0051] c) The required gaskets are pre-processed according to the designed hole diameter. The gaskets are made of elastic material and have water passages and annular water passage holes.

[0052] Step 2: Assembly and preparation work before pouring:

[0053] a) Prepare reinforced concrete formwork in advance according to the designed opening diameter. To ensure that the upper and lower surfaces of the cylinder are corresponding concave and convex surfaces, and that they match the shape of the gasket and fit together, the upper and lower formwork should also use customized regular-shaped formwork; clean the above formwork and apply release agent;

[0054] b) Setting up the forming template and inner and outer support frames to form the mold at the precast site, fixing the precast steel plate at the corresponding position of the mold, and fixing the precast longitudinal and circumferential steel bars at the corresponding positions on both sides of the steel plate after binding;

[0055] c) After the steel plate and steel bar positioning and assembly are completed, in order to ensure that the thickness of the protective layer meets the requirements, 3cm-thick cushion blocks are used on the inner and outer steel bars, and bolts are used to firmly fix the mold joints to prevent leakage during concrete pouring and affect the forming quality, and paper adhesive tape is pasted between the joints and the forming template.

[0056] Step 3: Pouring concrete and removing the mold for maintenance:

[0057] a) Pouring reinforced concrete cylinder shell: The concrete is supplied by the mixing system and transported to the construction site by concrete tank trucks. The concrete is unloaded into the mold by cooperating with the concrete pump. The concrete pouring requires to be completed at one time, and the insertion type vibrating rod is used to ensure the compactness of the concrete, and the rod is inserted quickly and withdrawn slowly, and the surface is observed to ensure that there is no bubble overflow;

[0058] b) After the concrete is vibrated and compacted, the upper side should be finished to have concave and convex surfaces to ensure smooth jointing of the cylinder shell;

[0059] c) After the concrete pouring is completed, the concrete should be watered in time to ensure the surface forming quality and prevent cracking;

[0060] d) After the maintenance reaches the standard strength, the mold is removed in sequence, and the cylinder shell surface is cleaned to be smooth and flat, and heavy hammering of the mold is strictly prohibited; at the same time, the mold surface should be cleaned in time, and the deformed position of the mold should be repaired; the surface temperature should not differ from the ambient temperature by more than 20℃ when the mold is removed.

[0061] Step 4: Bonding gasket: The precast gasket is bonded to the top surface of the steel plate and reinforced concrete cylinder shell using high-strength adhesive. To ensure the bonding quality, a bonding test should be conducted in advance to select appropriate high-strength adhesive;

[0062] Step 5: Stacking protection: After the above steps are completed, the precast reinforced concrete cylinder shell is stored in the finished product room and stacked according to the hoisting sequence and pouring sequence.

[0063] Step 6: On-site installation and grouting:

[0064] a) A high-pressure waterway precast reinforced concrete sandwich steel plate lining structure is hoisted into a transport vehicle and transported to the shaft head platform. A 100t crane is used in the shaft, and manual chain hoists are used to assist the hoisting of the finished product to the shaft head platform, and the shaft hoisting system is used to slowly hoist the finished product into the excavated shaft. During hoisting, it should be ensured that the various hoisting connections are reliable, and the cylinder structure should be protected from bumps to ensure the appearance quality. Before hoisting, a trial hoisting should be conducted, and after the trial hoisting is normal, the formal hoisting can be conducted.

[0065] b) When the prefabricated lining structure is close to the working surface, the installers should use guide ropes to assist in positioning to ensure that the lining structure has consistent elevation and gaps. After installation, a flatness test should be carried out.

[0066] c) A φ25mm contact grouting iron pipe is pre-embedded between the lining structure and the surrounding rock. The iron pipe is led to the outside of the lining structure. After the hoisting is completed, the end is sealed with a template. Then, a thick grout with a water-cement ratio of 0.5:1 and a grouting pressure of 0.5MPa is used to fill the space between the lining structure and the surrounding rock to ensure that the lining structure and the surrounding rock are in close contact and jointly bear the load during the high-pressure waterway process.

[0067] Furthermore, this specification should be considered as a whole, and the above-described embodiments are not the only independent technical solutions of this invention. The technical solutions in the embodiments can be appropriately combined and adjusted to form other embodiments that can be understood by those skilled in the art.

Claims

1. A precast reinforced concrete sandwich steel plate lining structure for high-pressure water channels, characterized in that: The structure includes a steel plate (1), reinforcing bars (2), a reinforced concrete shell (3), a gasket (4), surrounding rock (5), a swivel (101) and a pre-reserved groove (102) on the steel plate (1), and a swivel pre-reserved hole (401), a water passage (402), and an annular water passage hole (403) on the gasket (4). The steel plate (1) is located in the middle of the reinforced concrete shell (3), and a swivel (101) is provided on one side of the steel plate (1). The reinforcing bars (2) include longitudinal reinforcing bars (201) and circumferential reinforcing bars. The reinforcing bars (202) are set inside the reinforced concrete shells (3) on both sides of the steel plate (1); the gaskets (4) are set on one side of the steel plate (1) and the reinforced concrete shells (3), and the gaskets (4) are provided with bull's ear reserved holes (401). The bull's ear (101) passes through the bull's ear reserved holes (401) on the gaskets (4) and is hidden in the reserved groove (102) of the steel plate (1) of another precast reinforced concrete sandwich steel plate lining structure when the lining structure is installed. The reserved groove (102) is sized to accommodate the bull's ear ( 101) Enter; The gasket (4) is provided with a water passage (402) and an annular water passage (403). The annular water passage (403) is distributed in the 360° range along the inner ring of the gasket and in the radial direction on the broken line segment of the platform. The water passage (402) is distributed at equal intervals of 90° along the circumferential direction of the gasket (4) and is connected to the annular water passage (403). The gasket (4) is an elastic material that can produce a certain elastic deformation under pressure. After the prefabricated lining structure is installed, when the high-pressure waterway is filled with water, the water in the waterway flows through. The water passage (402) is filled with annular water passage holes (403). The annular water passage holes (403) can expand under the action of water pressure and tightly squeeze the reinforced concrete shell (3). The surrounding rock (5) is connected to the outside of the reinforced concrete shell (3) through a grouting layer. The inner and outer surfaces of the steel plate (1) are smooth curved surfaces. Steel ribs of a certain thickness are set at equal intervals on the inner and outer surfaces to prevent them from falling off the reinforced concrete shell (3) during installation and lifting. During the operation of the high-pressure waterway, the steel plate (1) and the reinforced concrete shell (3) jointly bear the load.

2. The precast reinforced concrete sandwich steel plate lining structure for high-pressure waterways according to claim 1, characterized in that: The bull's ear (101) and the steel plate (1) are an integral structure, formed by welding or cutting; the reserved groove (102) is formed by cutting on the steel plate (1).

3. The precast reinforced concrete sandwich steel plate lining structure for high-pressure waterways according to claim 1, characterized in that: The upper and lower surfaces of the reinforced concrete shell (3) are corresponding concave and convex surfaces, which are consistent with the shape of the gasket (4) and can fit together. The shell (3) is generated by using a regular-shaped template during the casting and prefabrication process.

4. A construction method for a precast reinforced concrete sandwich steel plate lining structure for high-pressure waterways according to any one of claims 1-3, characterized in that, The construction steps include the following: S1: Prefabricated key components, including: a) A shed structure is erected in the prefabrication plant, with a prefabrication room, a steel plate and steel bar processing room, a curing room and a finished product room respectively; according to the dimensional requirements such as the diameter and thickness of the shaft lining, the materials are prepared, rolled and welded into steel plates (1) in the prefabrication plant, the steel ribs are welded to the inner and outer surfaces of the steel plates, and the bull ears (101) are pre-reserved with the steel plates (1) by welding or cutting to form an integral structure; and a reserved groove (102) is cut on the steel plates (1). b) Based on the diameter of the shaft lining, longitudinal steel bars (201) and circumferential steel bars (202) of the corresponding length should be pre-processed at the steel bar processing plant. During processing, the surface of the steel bars should be cleaned, and the dimensions of various steel bars should conform to the dimensions in the drawings and meet the requirements of the specifications. The processed steel bars should be numbered. c) The required gasket (4) is pre-processed according to the designed hole diameter. The gasket is made of elastic material and has a water passage (402) and an annular water passage hole (403). S2: Assembly and preparation work before pouring: a) Prepare reinforced concrete templates in advance according to the designed hole diameter; in order to ensure that the upper and lower surfaces of the cylinder are corresponding concave and convex surfaces and that they are consistent with the shape of the gasket (4) and can fit together, the upper and lower templates should also adopt customized regular shape templates; clean the templates and apply release agent. b) Set up a prefabrication template and internal and external support frame at the prefabrication site to form a mold, fix the prefabricated steel plate (1) in the corresponding position of the mold, and tie the prefabricated longitudinal steel bar (201) and circumferential steel bar (202) to the corresponding positions on both sides of the steel plate (1). c) After the steel plate and reinforcing bar are positioned and assembled, in order to ensure that the protective layer thickness meets the requirements, 3cm thick pads are placed on the inner and outer reinforcing bars. To prevent grout leakage during concrete pouring from affecting the molding quality, bolts are used to secure the mold interface. Paper tape is pasted at the joint position and the gap between the mold template. S3: Concrete pouring and formwork removal / curing: a) Pouring reinforced concrete shell (3): Concrete is supplied centrally by the mixing system and transported to the construction site by concrete mixer truck. The concrete is then unloaded into the mold by the overhead pump. Concrete pouring is required to be completed in one go. To ensure that the concrete is poured densely, an immersion vibrator is used. The vibrator is inserted quickly and removed slowly. Once no more air bubbles are observed on the surface, it is ready. b) After the concrete is vibrated and compacted, the upper side should be rounded to form an uneven surface to ensure smooth connection of the shell. c) After the concrete is poured, it should be watered and cured in time to ensure the quality of the concrete surface and to prevent cracking. d) After curing to the standard strength, remove the templates in sequence and clean the outer surface of the cylinder shell to make it flat and smooth. It is strictly forbidden to hammer the mold with heavy objects. At the same time, the surface of the mold should be cleaned in time and the deformed parts of the mold should be repaired. The surface temperature should not differ from the ambient temperature by more than 20°C when removing the mold. S4: Bonding gasket: The prefabricated gasket (4) is bonded to the top surface of the steel plate (1) and the reinforced concrete shell (3) using a high-strength adhesive. To ensure the bonding quality, a bonding test should be conducted in advance to select a suitable high-strength adhesive. S5: Stacking and protection: After the above steps are completed, the precast reinforced concrete shell (3) is stored in the finished product room and stacked in sections according to the hoisting sequence and pouring sequence; S6: On-site installation and grouting: a) A precast reinforced concrete sandwich steel plate lining structure for a high-pressure waterway is hoisted into a transport vehicle and transported to the shaft opening platform. Inside the shaft, a 100t crane is used, with manual hoists assisting in hoisting the finished product to the shaft opening platform. The shaft lifting system is then used to slowly lower it into the excavated shaft. During hoisting, it is essential to ensure reliable connections of all lifting tools and to protect the cylindrical structure from impacts to maintain its appearance quality. A trial hoisting should be conducted before the actual hoisting, and only after the trial hoisting is successful can the formal hoisting proceed. b) When the prefabricated lining structure is close to the working surface, the installers should use guide ropes to assist in positioning to ensure that the lining structure has consistent elevation and gaps. After installation, a flatness test should be carried out. c) A φ25mm contact grouting iron pipe is pre-embedded between the lining structure and the surrounding rock. The iron pipe is led to the outside of the lining structure. After the hoisting is completed, the end is sealed with a template. Then, a thick grout with a water-cement ratio of 0.5:1 and a grouting pressure of 0.5MPa is used to fill the space between the lining structure and the surrounding rock to ensure that the lining structure and the surrounding rock are in close contact and jointly bear the load during the high-pressure waterway process.

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