Large-diameter assembled thin-walled steel plate pool and construction method thereof

Abstract

A large-diameter assembled thin-walled steel plate pool and a construction method thereof belong to the technical field of municipal water conservancy projects. The pool comprises a center column, an outer column, a surrounding wall steel plate and a cable. The outer column is evenly arranged around the center column, a half-circular surrounding wall steel plate is installed between adjacent outer columns to form the surrounding wall of the pool, the bottom end and the top end of the outer column are connected by a support rod, the outer columns are connected by a pull rod, the outer column and the center column are connected by a cable, an inner container is sleeved on the inner side of the surrounding wall and the ground inside the pool, and the inner container is placed on a fine sand cushion. The cable system transmits the radial horizontal thrust of the pool surrounding wall to the center column, which is balanced and counteracted in the horizontal direction. The structure reduces the horizontal lateral tension of the pool wall, significantly improves the vertical stiffness and horizontal overturning resistance of the thin-walled steel plate pool, improves the safety, and strengthens the convenience and economy. It can be widely used in water conservancy and municipal engineering.

Description

Technical Field

[0001] This invention belongs to the field of municipal water conservancy engineering technology, specifically relating to a large-diameter prefabricated thin-walled steel plate water tank and its construction method. Background Technology

[0002] Prefabricated thin-walled steel plate water tanks are a common type of water storage facility, widely used in water conservancy and agricultural irrigation. They are assembled on-site from prefabricated components, offering advantages such as simple and rapid construction, portability, and easy recycling. Furthermore, prefabricated thin-walled steel plate water tanks have lower requirements for engineering geological conditions, do not occupy permanent land, and possess good adaptability and economy, making them particularly suitable for temporary water conservancy projects.

[0003] However, existing prefabricated thin-walled steel plate water tanks have obvious technical defects in practical applications, mainly in the following aspects:

[0004] The existing thin-walled steel plate water tanks rely solely on a single cylindrical structure to bear the downward pressure from the upper structure and the horizontal thrust and tension forces. The structural design lacks an effective force transmission system to conduct and distribute the load. Small-diameter water tanks exhibit an overall tubular structure with excellent mechanical properties. However, as the tank diameter increases, the chord height per unit arc length of the tank wall decreases, and the wall shape gradually shifts from tubular to flat. Since the efficiency of a plate structure in bearing loads perpendicular to the plate surface is extremely low, and the thin-walled steel plate has poor bending resistance, the stress state of the tank wall deteriorates with increasing diameter, leading to a rapid decline in the marginal utility of increasing the steel plate wall thickness and strength.

[0005] Insufficient Performance: Existing thin-walled steel plate water tanks have low overall stiffness and weak resistance to deformation, both vertically and horizontally. They are highly susceptible to localized deformation or even complete overturning under unbalanced loads or external loads. The overall performance of thin-walled steel plate water tanks depends entirely on the properties of the tank wall material itself. In existing technologies, as the diameter of the water tank increases, the horizontal tensile force on the tank wall increases exponentially, easily leading to deformation or even cracking of the tank wall. To improve tensile strength, thicker and stronger steel plates must be used to construct large-diameter water tanks, drastically increasing costs. Moreover, due to the decreasing marginal utility of thicker steel plates, the performance improvement becomes less significant with larger diameters.

[0006] The trade-off between economy and safety: To enhance the stability and safety of water tanks, existing technologies typically require increasing the thickness of the tank walls or employing complex reinforcement measures. However, this leads to a significant increase in material costs, reducing the economic advantages of prefabricated water tanks. How to improve the safety and stability of water tanks while maintaining economic efficiency is a major challenge facing existing technologies.

[0007] Limited Scope of Application: Due to the aforementioned structural design flaws and limitations in material strength, the overall rigidity of large-diameter water tanks is difficult to improve effectively. This makes existing prefabricated thin-walled steel plate water tanks generally only suitable for low-water-level water storage projects, unable to meet the needs of large-diameter, deep-water-level water conservancy projects, greatly limiting their widespread application in water resource development, utilization, and management in large-scale municipal engineering, industry, agriculture, and ecological fields. Summary of the Invention

[0008] To address the aforementioned problems, this invention proposes a novel large-diameter prefabricated thin-walled steel plate water tank. Through innovative structural design and force transmission system, it significantly improves the overall rigidity and anti-overturning capacity of the water tank, overcomes the shortcomings of existing technologies, and expands the application scope of prefabricated thin-walled steel plate water tanks.

[0009] A large-diameter prefabricated thin-walled steel plate water tank, characterized by: a central column, outer columns, surrounding steel plates, cables, and a hydraulic membrane; the bottom of the central column is buried underground at a depth of 1 / 6 of its total height; a lightning rod is installed at the top of the central column; several anchors are circumferentially installed above ground at the top, upper, and bottom of the central column to anchor the cables; precast concrete rafts are evenly arranged circumferentially around the central column; outer columns are erected on the rafts, and the outer columns are steel-concrete truss beams made of structural steel with flat surfaces on both sides; a semi-circular section protruding outwards with a diameter equal to the line connecting the outer columns is installed between adjacent outer columns. The steel wall panels are bolted to the flat surface of the outer columns using clamps. The outer columns and the steel wall panels are connected sequentially with intervals to form the enclosure of the pool. Cables are installed at the bottom of the outer columns to connect to the bottom anchor of the central column, and cables are installed at the top of the outer columns to connect to the top anchor of the central column. The bottom and top of the outer columns, and adjacent outer columns are connected top-to-top with struts. Between the intermittent outer columns, tie rods are used for mutual support. The struts and tie rods combine to form a triangular support network between the bottom and top of the outer columns. Scissor bracing is installed on the inner side of the pool between adjacent outer columns. The scissor bracing is connected to the outer columns using connecting rods with flanges.

[0010] A hydraulic membrane is laid close to the inner side of the enclosure wall and the ground inside the pool, and spliced ​​together to form a whole water storage tank. The top edge of the hydraulic membrane on the inner side of the enclosure wall is fixedly connected to the top of the enclosure wall. A waterproof cloth is installed on the top of the pool, and the outer edge of the cap is connected to the top surface of the hydraulic membrane inside the enclosure wall. Several rainwater collection holes are opened along the edge of the cap. The cap is suspended from the cable by a rope. The central part of the cap is closed and connected to the central column. An opening is made in the hydraulic membrane at the central column and a flange is used to seal the connection with the central column. A water outlet pipe and a sludge discharge pipe are buried at the bottom of the pool. The pipe opening at the inner end of the pool is connected to the hydraulic membrane through a composite water tank joint, and the connection is flush with the bottom of the pool. The hydraulic membrane is placed on a fine sand cushion layer. The thickness of the fine sand cushion layer around the enclosure wall is greater than the thickness of the fine sand cushion layer in other locations.

[0011] The reservoir is constructed using a central column, outer columns, steel plates for the enclosure, cables, and a hydraulic membrane, forming a composite enclosure with an independent waterproof layer. The central column is embedded underground at its base. Cables transfer the outward radial thrust of the water from the surrounding walls to the central column, achieving symmetrical balance and mutual cancellation. The central column holds the outer columns in place, preventing the enclosure from overturning. The outer columns serve as supporting columns for the enclosure and also act as vertical stiffening beams, supporting the enclosure structure. The steel plates transfer the thrust on the enclosure to the cables; the steel plates on both sides are fixed to the outer columns, forming a small-radius semi-cylindrical surface; the outer columns and the steel plates are spaced apart and connected in sequence to form a composite enclosure structure for the entire pool; each pair of adjacent outer columns and the cylindrical surface of the steel plates between the columns constitutes an independent load unit; a hydraulic membrane is laid close to the inner side of the pool enclosure and the bottom of the pool, and the hydraulic membrane is spliced ​​into a whole in the pool to form an independent flexible waterproof layer to prevent the pool from leaking.

[0012] Furthermore, when the depth of the pool is greater than 20m, the external columns are configured as a vertical multi-layered structure.

[0013] Furthermore, when the diameter of the pool opening is greater than 10 times the width of an independent load unit of the enclosure wall, the cables adopt a connection method of first branching and then merging, specifically:

[0014] The external columns are divided into single-cable external columns and double-cable external columns, and the cables are divided into main cables and auxiliary cables;

[0015] Single-cable outer columns are arranged at equal intervals on a circle centered on the central column, and at least one double-cable outer column is arranged at equal intervals between the single-cable outer columns.

[0016] A main cable connected to the central column is installed on the outer column of a single cable. Two auxiliary cables with the same angle to the L line are installed on the outer column of a double cable. The auxiliary cables are connected to the main cables on both sides respectively, so that the resultant force of the double cables is consistent with the L line passing through the outer column of the double cable and the central column.

[0017] Furthermore, the portion of the cable located within the water body wraps around the buoy, balancing the cable's weight, keeping the cable horizontal, and reducing its sag.

[0018] A novel method for constructing a large-diameter prefabricated thin-walled steel plate water tank, characterized by the following steps:

[0019] S1. Based on the construction goals and site conditions, design the overall dimensions, water depth, and spacing of the external columns of the pool. Design the shape and specifications of the columns, external columns, wall steel plates, struts, tie rods, and raft slabs. Prefabricate the components according to the calculated quantities.

[0020] S2, clean the construction base of the water tank, level and compact it. The stability and bearing capacity of the central column and the outer column must meet the requirements. The raft foundation, as the expanded foundation of the outer column, must be able to bear the weight of the outer column, the steel plate of the enclosure wall, and the struts and tie rods. The settlement and deformation of the foundation in other locations must not endanger the foundation of the central column and the raft foundation.

[0021] S3, the central column is buried, the bottom circumferential anchor is at the same elevation as the bottom cable of the outer column, and the flange is at the same height as the hydraulic membrane at the bottom of the pool.

[0022] S4, pre-embed water outlet pipe and sludge discharge pipe, with the pipe opening at the same height as the bottom of the pool;

[0023] S5, install precast concrete raft slabs, erect external columns on the raft slabs, and erect supports and scaffolding to ensure the safety of the structure and assembly operations when erecting external columns and installing the enclosure.

[0024] S6. After the struts and tie rods are installed, lay the protective hydraulic fabric pad and the hydraulic membrane on the inner side of the enclosure. Then install the scissor bracing. After the enclosure is installed, set the cables. Connect the cables symmetrically in batches. After all the cables are connected, tighten them in a step-by-step symmetrical cycle. After the cables are tightened, remove the brackets and lay the fine sand pad at the bottom of the pool.

[0025] S7, Lay the hydraulic membrane at the bottom of the pool, weld the joints of the hydraulic membrane on the inner side of the enclosure and the hydraulic membrane at the bottom of the pool, and connect the flanges at the connection points of the hydraulic membrane with the central column, pipes and scissor bracing rods.

[0026] S8, the top of the water storage tank is sealed with a waterproof cloth and a lightning rod is installed.

[0027] The beneficial effects of this invention are as follows: The construction method of the large-diameter prefabricated thin-walled steel plate water tank, through innovative structural design, employs columns and cables to establish a force transmission system, transferring the radially radiating thrust of the water tank wall to the central column for symmetrical balance and mutual cancellation, forming an excellent self-balancing structure. By segmenting, the wall of the large-diameter water tank is divided into a composite wall composed of multiple small semi-cylindrical wall surfaces. In this structural form, each unit, consisting of a small semi-cylindrical wall and two external columns, constitutes an independent load-bearing unit. The radial horizontal thrust of this unit is transmitted to the central column via cables. The lateral thrusts are balanced and canceled out by the thrusts of adjacent units. Vertically, each unit forms a small-radius tubular structure with excellent vertical stiffness. With the support of the external columns, the vertical stiffness of the composite wall of the pool is further enhanced. The horizontal tensile stress borne by the steel plate of the wall is no longer transmitted between adjacent units, but is only related to the diameter of the wall of this unit. The diameter and water depth are the same, meaning that load units of the same specification have completely identical hydraulic load characteristics, construction materials, and structural shapes. By using different numbers of load units of the same specification, a series of large pools with different overall diameters can be formed. This method theoretically differentiates the limitation of material properties on the overall diameter of the pool, allowing the construction of large-diameter pools using materials with the same properties as the pools with the same diameter as the load units. The external columns are connected by struts, and the columns are connected by tie rods. The bottom and top of the columns form a triangular support grid, which, together with the scissor bracing on the facade, forms a stable three-dimensional support frame structure for the external columns of the pool.

[0028] This type of pool has high vertical stiffness, which is conducive to the construction of deep pools, optimizes the pool shape, reduces material consumption per unit volume, and reduces land occupation, thereby reducing costs. By using force transmission cables to centrally reinforce and improve the overturning resistance of the central column, the overturning resistance of the surrounding walls can be improved, reducing the scope of high-requirement engineering measures and further reducing costs. Currently, the unit cost of thin-walled steel plate pools can be reduced to less than 100 yuan, which is only 1 / 5 to 1 / 10 of that of conventional reinforced concrete pools.

[0029] The method described above has extremely simpler requirements regarding the topographic and geological conditions of the construction site compared to the requirements for reservoir basin topography and the impermeability of the underlying surface. Construction can proceed as long as the terrain is flat, has sufficient bearing capacity, and the soil fluidity is controllable. It is highly adaptable and can be built in deserts, riverbanks, shallow water areas of lakes and reservoirs, and urban areas. It can be constructed on a large scale in applications such as the expansion of shallow lakes and reservoirs and flood detention areas, seasonal riverbanks, and sponge city water storage and flood control. The water tanks are assembled on-site using prefabricated components, making construction simple, fast, and easy to move and recycle, meeting the modern engineering requirements for efficiency and environmental protection.

[0030] In summary, the method described above taps into the potential of thin-walled steel plate water tanks, improves the mechanical structure of the tank, enhances its resistance to damage, and improves safety. With the same performance materials and processes, safe and environmentally friendly large-diameter water tanks can be rapidly constructed, further enhancing their convenience and economy, greatly expanding their application scope, and facilitating their widespread promotion and safe use in water conservancy, municipal engineering, and other industrial, agricultural, and ecological fields. Attached Figure Description

[0031] Figure 1 This is a floor plan view of Example 1.

[0032] Figure 2 This is a partial plan view of Example 1.

[0033] Figure 3 This is a side sectional view of Example 1.

[0034] Figure 4 This is a schematic diagram of the combination of every two cables in Example 2.

[0035] Figure 5 This is a schematic diagram of the combination of every three cables in Example 2.

[0036] Figure 6 This is a partial side sectional view of Example 2.

[0037] Figure 7 This is a schematic diagram of the scissor bracing installation.

[0038] Figure 8 This is a detailed drawing of the connection between the hydraulic membrane and the steel plate of the enclosure.

[0039] Figure 9 This is a detailed drawing of the connection between the hydraulic membrane and the external column.

[0040] Figure 10 This is a schematic diagram of a connecting rod structure with a flange.

[0041] Among them: 1-Central column, 2-Cable, 21-Float, 3-Outer column, 31-Support rod, 32-Tie rod, 33-Scissor brace, 4-Hydraulic membrane, 41-Hydraulic fabric, 42-Flange, 43-Connecting rod, 5-Raft plate, 6-Enclosure steel plate, 61-Hydraulic fabric connecting plate, 62-Clamping plate, 63-Waterproof pad; 7-Fine sand cushion layer, 8-Anchor buckle, 9-Hanging rope, 10-Capping, 11-Rainwater collection hole, 12-Composite water tank connector, 13-Vertical pipe, 14-Outlet pipe, 15-Sludge discharge pipe, 16-Gate valve, 17-Lightning rod. Detailed Implementation

[0042] Example 1: A large-diameter prefabricated thin-walled steel plate water tank includes a central column 1, outer columns 3, surrounding steel plates 6, cables 2, and a hydraulic membrane 4. The bottom of the central column 1 is buried underground at a depth of 1 / 6 of its total height, and a lightning rod 17 is installed at the top of the central column 1. Several anchors 8 are circumferentially installed above ground at the top, upper, and bottom of the central column 1 to anchor the cables 2. Precast concrete raft slabs 5 are evenly arranged circumferentially around the central column 1, and outer columns 3 are erected on the raft slabs 5. The outer columns 3 are steel-concrete truss beams made of steel profiles, with flat surfaces on both sides. In this example, the water tank depth is greater than 20m, and the outer columns 3 are set as a vertical multi-layer structure. A semi-circular steel plate 6 protruding outwards, with the diameter of the line connecting the outer columns 3, is installed between adjacent outer columns 3. The steel plate 6 is fastened to the flat surface of the outer column 3 using clamps 62. The outer columns 3 and the steel plate 6 are connected to each other in a staggered manner to form the enclosure of the pool. A cable 2 is installed at the bottom of the outer column 3 and connected to the bottom anchor 8 of the central column 1. A cable 2 is installed at the top of the outer column 3 and connected to the top anchor 8 of the central column 1. The part of the cable 2 in the water wraps around the float, balances the weight of the cable 2, keeps the cable 2 in a horizontal position, and reduces sag.

[0043] The bottom and top of the outer columns 3 are connected by struts 31 to the top of each other. The outer columns 3 are connected by tie rods 32 to each other. The struts 31 and tie rods 32 are combined to form a triangular support network between the bottom and top of the outer columns 3. Scissor braces 33 are installed on the inner side of the pool between adjacent outer columns 3. The scissor braces 33 are connected to the outer columns 3 by connecting rods with flanges 42.

[0044] A hydraulic membrane 4 is laid close to the inner side of the enclosure wall and the ground inside the pool, and spliced ​​together to form an integral water storage tank. The top edge of the hydraulic membrane 4 on the inner side of the enclosure wall is fixedly connected to the top of the enclosure wall. A waterproof cloth cap 10 is installed on the top of the pool. The outer edge of the cap 10 is connected to the top surface of the hydraulic membrane 4 inside the enclosure wall. Several rainwater collection holes are opened along the edge of the cap 10. The cap 10 is suspended from the cable 2 by a hanging rope 9. The central part of the cap 10 is closed and connected to the central column 1. An opening is made at the hydraulic membrane 4 at the central column and sealed to the central column 1 using a flange 42. A water outlet pipe 14 and a sludge discharge pipe 15 are buried at the bottom of the pool. The pipe opening at the inner end of the pool is connected to the hydraulic membrane 4 through a composite water tank connector 12, and the connection is flush with the bottom of the pool. The hydraulic membrane 4 is placed on a fine sand cushion layer 7. The thickness of the fine sand cushion layer 7 around the enclosure wall is greater than the thickness of the fine sand cushion layer 7 at other locations.

[0045] A large-diameter prefabricated thin-walled steel plate water tank is constructed according to the following steps:

[0046] S1. Based on the construction goals and site conditions, design the overall dimensions, water depth, and spacing of the external columns of the water tank. Design the shape and specifications of the columns, external columns, wall steel plates, struts, tie rods, and raft slabs. Prefabricate the components according to the calculated quantities. This embodiment proposes to construct a water tank with a designed volume of 200,000 m³. 3 The design depth is 17.5m, the maximum span of the pool is 124.65m, and the height of the pool walls is 18m. The pool walls are divided into 36 semi-cylindrical wall units, each with a semi-cylindrical diameter of 10m. The central column is 24m long and buried at a depth of 4m. The walls are constructed of 3mm zinc-aluminum-magnesium steel plates, with a steel plate usage of approximately 10,200m³. 2 .

[0047] S2, clean the construction base surface of the water tank, level and compact it. The location, stability and bearing capacity of the central column 1 and the outer column 3 must meet the requirements. The raft slab 5, as the enlarged foundation of the outer column 3, must be able to bear the self-weight of the outer column 3, the wall steel plate 6 and the strut 31. If the settlement and deformation of the foundation in other locations endangers the foundation of the central column 3 and the raft slab 5, improvement measures such as replacement or mixing shall be taken.

[0048] S3, bury the central column 1 with a burial depth of not less than 1 / 6 of its total height, and install several anchors 8 in a circumferential manner at the top, upper part and bottom of the pool of the central column, and make the bottom circumferential anchors 8 have the same elevation as the bottom cable 2 of the outer column 3.

[0049] S4, pre-embed water outlet pipe 14 and mud discharge pipe 15, gate valve 16 is installed at the outer end of each pipe, and anti-mud and sand vertical pipe 13 is installed at the inner end of the water outlet pipe 14.

[0050] S5, with the central column 1 as the center, precast concrete raft slabs 5 are evenly placed in a circumferential direction. Supports and scaffolding are erected to ensure the safety of the structure and assembly operations. Outer columns 3 are erected on the raft slabs 5. The outer columns 3 are steel pipe concrete truss beams made of steel sections, with flat surfaces on both sides.

[0051] S6, the bottom and top ends of adjacent outer columns 3 are connected by struts 31, and the bottom and top ends of spaced outer columns 3 are connected by tie rods 32. The struts and tie rods are combined to form a triangular support network between the bottom and top of the outer columns. After the struts 31 and tie rods 32 are installed at the bottom and top of the outer columns 3, a hydraulic fabric 41 is laid on the inner side of the pool as a protective pad, and then a hydraulic membrane 4 is laid on the inner wall of the pool. Then, scissor braces 33 are installed between adjacent outer columns 3 on the inner side of the pool. The scissor braces 33 are connected to the outer columns 3 by connecting rods 43 with flanges 42. A semi-circular wall protruding outward with the diameter of the line connecting the outer columns is installed between adjacent outer columns 3. Steel plate 6, the enclosure steel plate 6 is fastened to the flat surface of the outer column 3 with clamps. The outer column 3 and the enclosure steel plate 6 are connected to each other in a staggered manner to form the enclosure of the water tank. The bottom end of the outer column 3 is equipped with a cable 2 connected to the bottom anchor 8 of the central column 1, and the top end of the outer column 3 is equipped with a cable 2 connected to the top anchor 8 of the central column 1. After all the cables 2 are connected, the cables 2 are tightened step by step in a symmetrical cycle. After the cables 2 are tightened, the brackets and scaffolding are disassembled and removed. A fine sand cushion layer 7 is laid at the bottom of the water tank so that the flange 42 on the central column 1 is at the same height as the water membrane 4 at the bottom of the water tank. The inner end of the water outlet pipe 14 and the sludge discharge pipe 15 is at the same height as the water membrane 4 at the bottom of the water tank.

[0052] S7, Lay the bottom water lining membrane 4 of the pool, weld the joint between the wall water lining membrane 4 and the bottom water lining membrane 4; use flange 42 to seal and connect the water lining membrane 4 and the central column 1; use composite water tank connector 12 to seal and connect the outlet pipe 14 and the water lining membrane 4, and add a vertical pipe 13 to the inner end of the outlet pipe; use composite water tank connector 12 to seal and connect the sludge discharge pipe 15 and the water lining membrane 4.

[0053] S8, a waterproof cloth cap 10 is installed at the top of the water storage tank. The outer edge of the cap 10 is connected to the top edge of the hydraulic membrane 4. The cap 10 is suspended from the cable 2 by the hanging rope 9. The inner side of the cap 10 is closed and connected to the anchor 8 at the top of the central column 1. Several rainwater collection holes 11 are opened at the low-lying area near the top of the water tank wall of the cap 10 to collect or drain rainwater and prevent water accumulation at the top of the cap 10. Finally, a lightning rod 17 is installed at the top of the central column 1.

[0054] Example 2: When the diameter of the pool is greater than 10 times the width of the independent load unit of the enclosure wall, there are many enclosure wall units and long cables. Some cables 2 are combined and set up, and a connection method of first branching and then merging is adopted.

[0055] Cable 2 adopts a bifurcation-then-merging connection method, dividing the outer column 3 into single-cable outer columns and double-cable outer columns, and cable 2 into main cables and auxiliary cables; the single-cable outer columns are evenly spaced on a circle centered on the central column 1, and a double-cable outer column is evenly spaced between the single-cable outer columns, such as... Figure 4As shown, or two equally spaced double-cable external columns are installed between single-cable external columns, such as... Figure 5 As shown;

[0056] A main cable connected to the central column 1 is installed on the outer column of the single cable. Two auxiliary cables with the same angle to the L line are installed on the outer column of the double cable. The auxiliary cables are connected to the main cables on both sides respectively, so that the resultant force of the double cables is consistent with the L line passing through the outer column of the double cable and the central column.

[0057] When the pool depth exceeds 20m, the outer column 3 is set in sections, and a layer of cable is added at the joint to connect it with the central column 1; the cable 2 located in the water covers the float 21 to increase buoyancy and reduce the sag of the cable 2.

[0058] The steel plates 6 of the enclosure wall and the steel plates of the enclosure wall and the outer columns 3 are sealed and bolted or welded with waterproof gaskets 63 to form a self-waterproof structure. On the inner side of the enclosure wall, along the edge of the fine sand cushion layer 7, a continuous closed hydraulic fabric connecting plate 61 is set. The edge of the hydraulic membrane 4 at the bottom of the pool is sealed and connected to the hydraulic fabric connecting plate 61 on the enclosure wall with waterproof gaskets 63 and clamps 62 to achieve overall waterproofing of the pool and eliminate the need for laying hydraulic membrane on the inner side of the enclosure wall.

[0059] The remaining structure and construction method are the same as in Example 1.

Claims

1. A large-diameter prefabricated thin-walled steel plate water tank, characterized in that: The enclosure consists of a central column, outer columns, steel plates, cables, and a hydraulic membrane. The bottom of the central column is buried underground to a depth of 1 / 6 of its total height. A lightning rod is installed at the top of the central column. Several anchors are installed circumferentially above ground level at the top, upper, and bottom of the central column. Precast concrete raft slabs are evenly arranged circumferentially around the central column. Outer columns, which are steel-concrete truss beams made of steel sections, are erected on the raft slabs and have flat surfaces on both sides. A semi-circular steel plate protruding outwards, with the diameter of the line connecting the outer columns, is installed between adjacent outer columns. The steel plate is secured with clamps. The outer columns and the surrounding steel plates are connected sequentially and alternately on the flat surface of the outer columns to form the enclosure of the pool. Cables are installed at the bottom of the outer columns to connect to the bottom anchor of the central column, and cables are installed at the top of the outer columns to connect to the top anchor of the central column. The bottom and top of the outer columns are connected to adjacent outer columns by struts, and tie rods are used between the spaced outer columns to pull each other. The struts and tie rods combine to form a triangular support network between the bottom and top of the outer columns. Scissor bracing is installed on the inner side of the pool between adjacent outer columns. The scissor bracing is connected to the outer columns by connecting rods with flanges. A hydraulic membrane is laid close to the inner side of the enclosure wall and the ground inside the pool, and spliced ​​together to form a whole water storage tank. The top edge of the hydraulic membrane on the inner side of the enclosure wall is fixedly connected to the top of the enclosure wall. A waterproof cloth is installed on the top of the pool, and the outer edge of the cap is connected to the top surface of the hydraulic membrane inside the enclosure wall. Several rainwater collection holes are opened along the edge of the cap. The cap is suspended from the cable by a rope. The central part of the cap is closed and connected to the central column. An opening is made in the hydraulic membrane at the central column and a flange is used to seal the connection with the central column. A water outlet pipe and a sludge discharge pipe are buried at the bottom of the pool. The pipe opening at the inner end of the pool is connected to the hydraulic membrane through a composite water tank joint, and the connection is flush with the bottom of the pool. The hydraulic membrane is placed on a fine sand cushion layer. The thickness of the fine sand cushion layer around the enclosure wall is greater than the thickness of the fine sand cushion layer in other locations. The reservoir is constructed using a central column, outer columns, steel plates for the enclosure, cables, and a hydraulic membrane, forming a composite enclosure with an independent waterproof layer. The central column is embedded underground at its base. Cables transfer the outward radial thrust of the water from the surrounding walls to the central column, achieving symmetrical balance and mutual cancellation. The central column holds the outer columns in place, preventing the enclosure from overturning. The outer columns serve as supporting columns for the enclosure and also act as vertical stiffening beams, supporting the enclosure structure. The steel plates transfer the thrust on the enclosure to the cables; the steel plates on both sides are fixed to the outer columns, forming a small-radius semi-cylindrical surface; the outer columns and the steel plates are spaced apart and connected in sequence to form a composite enclosure structure for the entire pool; each pair of adjacent outer columns and the cylindrical surface of the steel plates between the columns constitutes an independent load unit; a hydraulic membrane is laid close to the inner side of the pool enclosure and the bottom of the pool, and the hydraulic membrane is spliced ​​into a whole in the pool to form an independent flexible waterproof layer to prevent the pool from leaking.

2. The large-diameter prefabricated thin-walled steel plate water tank as described in claim 1, characterized in that... When the depth of the pool is greater than 20m, the external columns are set as a vertical multi-layer structure.

3. A large-diameter prefabricated thin-walled steel plate water tank as described in claim 1, characterized in that... The cable partially encloses the buoy within the water body.

4. The construction method of a large-diameter prefabricated thin-walled steel plate water tank as described in claim 1, characterized in that... Includes the following steps: S1. Based on the construction goals and site conditions, design the overall dimensions, water depth, and spacing of the external columns of the pool. Design the shape and specifications of the columns, external columns, wall steel plates, struts, tie rods, and raft slabs. Prefabricate the components according to the calculated quantities. S2, clean the construction base surface of the water tank, level and compact it. The stability and bearing capacity of the central column and the outer column must meet the requirements. The raft foundation, as the expanded foundation of the outer column, must be able to bear the weight of the outer column, the steel plate of the enclosure wall and the struts and tie rods. The settlement and deformation of the foundation in other locations must not endanger the foundation of the central column and the raft foundation. S3, the central column is buried, the bottom circumferential anchor is at the same elevation as the bottom cable of the outer column, and the flange is at the same height as the hydraulic membrane at the bottom of the pool. S4, pre-embed water outlet pipe and sludge discharge pipe, with the pipe opening at the same height as the bottom of the pool; S5, install precast concrete raft slabs, erect external columns on the raft slabs, and erect supports and scaffolding to ensure the safety of the structure and assembly operations when erecting external columns and installing the enclosure. S6. After the struts and tie rods are installed, lay the protective hydraulic fabric pad and the hydraulic membrane on the inner side of the enclosure. Then install the scissor bracing. After the enclosure is installed, set the cables. Connect the cables symmetrically in batches. After all the cables are connected, tighten them in a step-by-step symmetrical cycle. After the cables are tightened, remove the brackets and lay the fine sand pad at the bottom of the pool. S7, Lay the hydraulic membrane at the bottom of the pool, weld the joints of the hydraulic membrane on the inner side of the enclosure and the hydraulic membrane at the bottom of the pool, and connect the flanges at the connection points of the hydraulic membrane with the central column, pipes and scissor bracing rods. S8, the top of the water storage tank is sealed with a waterproof cloth and a lightning rod is installed.

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