Underwater concrete non-demolition assembly type water-permeable formwork

Abstract

The utility model relates to water conservancy engineering technical field especially suitable for the underwater concrete pouring scene such as revetment, dam repair etc. The utility model provides a kind of underwater concrete dismantling-free assembly type water-permeable formwork, including three prism frame, reinforcing bar and water-permeable panel. Water-permeable panel is composed of grid support frame, galvanized steel wire net and water-permeable formwork cloth, and is sequentially attached to the inside of frame. Adjacent frame is connected by U-shaped buckle, and formwork bottom is anchored to base structure by anchor bolt. The first layer formwork bottom is leveled with mold bag concrete. The formwork structure is simple, light in weight, easy to hoist and assemble underwater. Water-permeable panel discharges accumulated water and air, avoids grout leakage, forms dense hardening layer on concrete surface. The dismantling-free design has protection and reinforcement functions, eliminates formwork removal safety hazard. It significantly reduces cost, shortens construction period, and can still be stably installed under deep water area, high flow rate and complex terrain conditions.

Description

Technical Field

[0001] This utility model relates to the field of water conservancy engineering technology, specifically to an underwater concrete permeable formwork that can be assembled without dismantling. Background Technology

[0002] In the fields of water conservancy and waterway engineering, underwater concrete pouring is a key technical step in projects such as bank protection, dam repair, river regulation, and marine pile foundation protection. However, existing underwater concrete formwork technologies have many shortcomings and are difficult to meet the construction needs in deep water areas, high current velocities, and complex terrain conditions. Currently, common underwater formwork mainly includes combined steel formwork, standardized large steel formwork, and formwork bags. Combined steel formwork is difficult to assemble underwater, has a complex support structure, requires divers to work for long periods of time, and carries high safety risks. Furthermore, the bottom of the formwork has poor contact with uneven riverbeds, easily leading to grout leakage or the formation of holes. Demolding requires underwater cutting operations, relies on large lifting equipment, and results in high construction costs. While standardized large steel formwork has high strength and rigidity, its manufacturing process is complex, its size and weight are large, it requires sophisticated lifting equipment, has harsh on-site operating conditions, and has high material and manufacturing costs. It is also difficult to install underwater and is not suitable for complex terrain conditions. Concrete-filled formwork, relying on natural overlap between components, suffers from weak bonding, making it unsuitable for forming large-volume concrete structures. Its insufficient shear strength and inability to adapt to complex geometries limit its application. Existing combined steel formwork requires underwater dismantling, relying on large equipment. Currently, there is a lack of a non-dismantling formwork system that can adapt to complex underwater terrain while offering convenient construction and low safety risks. Therefore, there is an urgent need to optimize formwork structure and construction techniques to address these issues.

[0003] Furthermore, the underwater environment places higher demands on the durability and corrosion resistance of formwork materials. Traditional formwork is prone to performance degradation due to corrosion and aging during long-term underwater use, affecting the safety and service life of the structure. Simultaneously, during underwater concrete pouring, factors such as water flow impact, lateral pressure, and topographical undulations make the stability, shear strength, and overall stiffness of the formwork critical design challenges. How to improve the construction efficiency, durability, and economy of formwork through reasonable structural design and material selection, while ensuring the surface quality and overall performance of concrete, is a core issue that urgently needs to be addressed in current underwater concrete formwork technology. This invention aims to provide a simple, convenient, and non-removable permeable formwork system to overcome the shortcomings of existing technologies and meet the construction needs in deep water areas, high flow velocities, and complex terrain conditions. Utility Model Content

[0004] This utility model provides an underwater concrete permeable formwork that can be assembled without dismantling, which solves the problems of difficult assembly, high safety risks, and the need for dismantling of existing underwater formwork.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] This utility model provides an underwater concrete permeable formwork that can be assembled without dismantling, comprising a triangular prism frame, multiple reinforcing steel bars set within the triangular prism frame, and a permeable panel set on the triangular prism frame; the permeable panel includes a grid support frame, a galvanized steel wire mesh, and a permeable formwork fabric for concrete engineering, which are sequentially attached. The grid support frame is welded to the inner corner of the triangular prism frame, the galvanized steel wire mesh is tied to the backwater side of the grid support frame, and the permeable formwork fabric for concrete engineering is lined to the backwater side of the galvanized steel wire mesh, with its bottom extending towards the backwater side to form a reverse edge; multiple triangular prism frames are provided, and adjacent triangular prism frames are assembled and connected by connectors, with their bottoms anchored to the base structure by fasteners.

[0007] Preferably, the triangular prism frame consists of a front support column, side connecting beams, a bottom anchor beam, and a rear support column; two front support columns and one rear support column are arranged parallel to each other to form the three longitudinal sides of the triangular prism; the ends of the two side connecting beams and the bottom anchor beam are welded together to form a triangular planar frame, and the two sets of triangular planar frames serve as the two end faces of the triangular prism, with their apexes welded to the upper and lower ends of the three support columns, together forming a closed frame structure; adjacent triangular prism frames are assembled and connected by connectors on the side connecting beams and the bottom anchor beam; the front support column, side connecting beams, bottom anchor beam, and rear support column are all angle steel, with the inside corners facing inward.

[0008] Preferably, the reinforcing bars include bottom cross bars and side diagonal bars; the bottom cross bars are arranged in an X-shape along the diagonal of the quadrilateral plane formed by the front support column, the bottom anchor beam, and the rear support column; the side diagonal bars are symmetrically arranged in the triangular planar frames on the left and right sides, with their ends welded to one of the side connecting beams and the bottom anchor beam respectively; four side diagonal bars are arranged parallel and inclined in one side of the triangular planar frame, and the four side diagonal bars are evenly distributed along the length of the bottom anchor beam; the reinforcing bars are made of threaded steel.

[0009] Preferably, the grid support frame is made of threaded steel bars with a diameter of 19-21 mm welded to the inner corner of the triangular prism frame, with the horizontal spacing of the threaded steel bars being 19-21 cm and the vertical spacing being 29-31 cm.

[0010] Preferably, the galvanized steel wire mesh has a wire diameter of 0.5-0.7 mm and a mesh size of 3×3 mm. It is tied to the back surface of the mesh support frame with double-strand tie wire. The tying points are distributed along the nodes of the threaded steel bars, and the overlap width of adjacent galvanized steel wire meshes is ≥15 cm.

[0011] Preferably, the permeable formwork fabric for concrete engineering has a thickness of 1-3 mm, is made of polypropylene fiber, and is pasted onto the back side of the galvanized steel wire mesh. The bottom of the permeable formwork fabric extends 10-14 cm towards the back side to form a reverse-edge structure; the permeability coefficient of the permeable formwork fabric is ≥0.4×10⁻⁶. -3 cm / s, longitudinal tensile strength ≥80kN / m.

[0012] Preferably, the connector is a U-shaped buckle, which is staggered along the height of the triangular prism frame, with adjacent U-shaped buckles facing opposite directions.

[0013] Preferably, the fastener is an anchor expansion bolt with an anchoring depth ≥300 mm; the anchor expansion bolt passes through the preset holes in the front support column, the bottom anchor beam and the rear support column respectively, to anchor the triangular prism frame to the base structure.

[0014] Preferably, the triangular prism frame has multiple layers. The bottom of the first layer of the triangular prism frame is leveled with geotextile concrete. The geotextile concrete has external dimensions of 0.3×0.3×0.2 meters and is made of high-strength woven polypropylene fabric.

[0015] Preferably, a non-standard component frame is also included; the non-standard component frame is set according to the requirements of the corner or irregular part of the project, its structural form is adapted to the triangular prism frame, it is assembled and connected with adjacent triangular prism frames or other non-standard component frames through connectors, and is anchored to the base structure through fasteners to adapt to the construction requirements of complex geometry.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. This utility model utilizes a permeable panel constructed from a triangular prism frame, sequentially fitted with a mesh support frame, galvanized steel wire mesh, and permeable formwork fabric for concrete engineering. Through the permeability and capillary action of the permeable panel, it effectively drains water and air accumulated during concrete pouring, preventing air bubble accumulation and grout leakage. This results in a dense, hardened layer on the concrete surface, improving surface quality and structural durability. Simultaneously, the non-removable design allows the formwork to form a permanent reinforcement layer after concrete pouring, sharing the load with the internal concrete and eliminating the safety risks of underwater demolding, thus providing both protection and reinforcement. The reverse-edge structure further prevents cement grout loss, enhancing the grout leakage prevention effect.

[0018] 2. The triangular prism frame of this utility model consists of a front support column, side connecting beams, a bottom anchoring beam, and a rear support column. It is constructed using angle steel welded together to form a closed frame structure with inward-facing internal corners, enhancing the overall rigidity and resistance to water flow impact. Adjacent frames are connected by U-shaped clips, and the bottom of the formwork is anchored to the base structure using expansion bolts. This design facilitates easy assembly, ensures a secure connection, and allows for rapid construction in complex underwater terrain conditions.

[0019] 3. The reinforcing steel bars of this utility model include bottom cross steel bars and side diagonal steel bars. The bottom cross steel bars are distributed in an X shape in the quadrilateral plane, and the side diagonal steel bars are symmetrically arranged at equal intervals in the triangular plane frame, forming a stable triangular and X-shaped force system, which significantly improves the shear strength and overturning stability of the formwork, and ensures the structural safety of the formwork in deep water areas and high flow velocity environments.

[0020] 4. The grid support frame of this utility model is welded with threaded steel bars of a specific diameter at a certain interval, providing solid support for the galvanized steel wire mesh and the permeable formwork fabric for concrete engineering; the galvanized steel wire mesh is tied to the back surface of the grid support frame with double-strand tie wire, with an overlap width of ≥15 cm, ensuring the stability and integrity of the steel wire mesh; the bottom of the permeable formwork fabric for concrete engineering extends to form a reverse edge structure, further preventing grout leakage, and multiple protections improve the reliability of the formwork.

[0021] 5. The connectors of this utility model adopt U-shaped buckles, which are staggered along the height of the frame and adjacent buckles face opposite directions, enhancing the tightness and stability of the connection between adjacent frames; the fasteners adopt anchor expansion bolts with an anchoring depth of ≥300 mm, ensuring a firm connection between the bottom of the formwork and the base structure, effectively resisting water flow impact and concrete lateral pressure.

[0022] 6. This utility model uses geotextile concrete for leveling at the bottom of the first-layer triangular prism frame. The geotextile concrete has specific dimensions and material, which can effectively fill the uneven gaps in the riverbed, providing a solid and flat installation foundation for the formwork, further preventing grout leakage and the formation of voids, and improving construction quality. Geotextile concrete leveling provides a flat installation foundation for the formwork, avoiding grout leakage and structural voids caused by bottom gaps.

[0023] 7. This utility model also includes a non-standard frame, which can be set according to the needs of the corners or irregular parts of the project. Its structure is compatible with the triangular prism frame. It can be assembled and connected with the adjacent frame through connectors, which can adapt to the construction needs of complex geometric shapes and expand the application range of the template.

[0024] 8. This utility model has a simple overall structure, uses less material, and is lightweight, making it easy to hoist and assemble underwater. It reduces the difficulty and safety risks for divers, eliminates the need for complex supports and large hoisting equipment, significantly reduces construction costs, and shortens the construction period. It has high practical value and promising prospects in the fields of water conservancy and water transport engineering. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the triangular prism frame of this utility model.

[0026] Figure 2 This is a schematic diagram showing the assembly effect of this utility model in actual application.

[0027] Figure 3 This is a cross-sectional schematic diagram showing the assembly effect of this utility model in actual application.

[0028] Figure 4 This is a schematic diagram of the layered structure of the permeable panel of this utility model.

[0029] In the above figures, the component names corresponding to the reference numerals are as follows:

[0030] 1. Triangular prism frame; 2. Non-standard component frame; 3. Mortar concrete; 4. Front support column; 5. Side connecting beam; 6. Bottom anchor beam; 7. Rear support column; 8. Bottom cross reinforcement; 9. Side diagonal reinforcement; 10. Grid support frame; 11. Galvanized steel wire mesh; 12. Permeable formwork fabric for concrete engineering. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings.

[0032] Example

[0033] Please refer to Figure 1-4 This utility model provides an underwater concrete permeable formwork that can be assembled without dismantling, which is particularly suitable for underwater concrete pouring scenarios such as bank protection, dam repair, river regulation, and marine pile foundation protection in water conservancy and waterway engineering fields. It is especially suitable for deep water areas, high flow velocities, and complex terrain conditions. The overall structure of the underwater concrete permeable formwork consists of a triangular prism frame 1, a non-standard component frame 2, a formwork concrete bag 3, a front support column 4, a side connecting beam 5, a bottom anchor beam 6, a rear support column 7, bottom cross reinforcement bars 8, side diagonal reinforcement bars 9, a mesh support frame 10, galvanized steel wire mesh 11, and permeable formwork fabric for concrete engineering 12.

[0034] Specifically, the triangular prism frame 1 is made of 50×50×4mm angle steel, cut and welded according to the design dimensions. The specific structure includes two front support columns 4, two rear support columns 7, a bottom anchor beam 6, and side connecting beams 5. The two front support columns 4 and one rear support column 7 are arranged parallel to each other, forming the three longitudinal sides of the triangular prism. Two sets of triangular planar frames are enclosed by the side connecting beams 5 and the bottom anchor beams 6, serving as the two end faces of the triangular prism. Their apexes are welded to the upper and lower ends of the three support columns, forming a stable closed frame structure. All internal corners are set inwards to enhance the frame rigidity and reduce water flow resistance.

[0035] Reinforcement is applied to the sides and bottom of frame 1. The bottom intersecting reinforcing bars 8 are made of Φ20mm threaded steel and are positioned within the quadrilateral plane formed by the front support column 4, the bottom anchor beam 6, and the rear support column 7, distributed in an X-shape along the diagonal. The intersections are fixed by through-hole plug welding. The side diagonal bracing bars 9 are also made of Φ20mm threaded steel and are symmetrically arranged within the triangular plane frames on both sides. Four side diagonal bracing bars 9 are parallel and inclined within one side of the triangular plane frame, evenly spaced along the length of the bottom anchor beam 6. The two ends of the side diagonal bracing bars 9 are welded to the side connecting beam 5 and the bottom anchor beam 6, respectively, forming a stable triangular load-bearing system. All welded parts are welded using manual arc welding (SMAW). Main welds, such as the angle steel internal corner connections, use equilateral fillet welds with a weld leg size of 4mm, continuously full-scale welded. Connections between the reinforcing bars and the frame use lap fillet welds with a weld leg size of 5mm, and a double-sided weld length ≥10d (d is the diameter of the reinforcing bar 20mm, i.e., ≥100mm). After welding, all welds must be sandblasted to remove rust and reach the Sa2.5 standard. The surface roughness should be controlled within the range of 50-80μm. Two coats of epoxy zinc-rich primer should be applied with a dry film thickness of ≥120μm to enhance underwater corrosion resistance.

[0036] Non-standard frame 2 is designed and manufactured according to the needs of corners or irregular parts of the project, and its structural form is compatible with the triangular prism frame 1. The dimensional adjustment of non-standard frame 2 must meet the requirements of overall rigidity and construction feasibility. The length of a single piece should be ≤6m and the height should be ≤4.5m. If it exceeds this range, it should be assembled in sections. For the formwork at the curve, it is advisable to adopt a gradient design with a preferred arc radius ≥18.8m. A smooth curve is achieved by splicing standard formwork less than 200mm wide. The single section of the broken line should be controlled within 1.5m, and the flatness error of the concrete surface should be ≤4mm. The gradient slope of the variable cross section should be ≤1:3. The formwork joints should be adjusted with wedge-shaped wooden strips. When the gap is >0.5mm, self-adhesive sealing strips should be pasted to prevent grout leakage. Non-standard frame 2 is assembled and connected to triangular prism frame 1 or other non-standard frame 2 through U-shaped buckles and anchored to the base structure with anchor expansion bolts to adapt to the construction needs of complex geometries.

[0037] A mesh support frame 10 is welded to the inner corner of the triangular prism frame 1. Threaded steel bars with a diameter of 20mm are used, with a preferred horizontal spacing of 20cm and a preferred vertical spacing of 30cm, forming a uniformly distributed support network. Galvanized steel wire mesh 11 is selected with a diameter of 0.6mm and a mesh size of 3×3mm. It is tied to the backwater side of the mesh support frame 10 (i.e., the side facing the concrete pouring) using double-strand binding wire. The binding points are distributed along the nodes of the threaded steel bars. The overlap width of adjacent galvanized steel wire mesh 11 is ≥15cm to ensure a tight fit with the support frame. The galvanized steel wire mesh 11 is hot-dip galvanized, with a single-sided zinc layer thickness ≥65μm (total thickness ≥130μm on both sides) and a zinc coating weight ≥90g / m². 2 It meets the durability requirements for underwater environments for more than 15 years.

[0038] The preferred thickness of the permeable formwork fabric for concrete engineering is 2mm, and the material is polypropylene fiber with a permeability coefficient ≥0.4×10⁻⁶. -3 The permeable template fabric has a tensile strength of ≥80kN / m (cm / s), longitudinal tensile strength ≥80kN / m, transverse tensile strength ≥60kN / m, and elongation ≤30%. It is pasted onto the back surface of the galvanized steel wire mesh 11, with the bottom extending 10cm towards the back surface to form a reverse edge. It is temporarily fixed to the bottom anchoring beam 6 with tie wire to prevent displacement of the template fabric during pouring. The overlap width between the permeable template fabric 12 and the galvanized steel wire mesh 11 is also ≥15cm, exceeding the industry standard of 10cm, reducing the risk of edge peeling. The microporous structure (pore size ≤0.1mm) of the permeable template fabric 12 forms capillary channels with the galvanized steel wire mesh 11, allowing water to drain through osmotic pressure difference.

[0039] The side connecting beams 5 and bottom anchoring beams 6 of the triangular prism frame 1 are drilled with holes at intervals of ≤300mm to accommodate Φ12mm U-shaped clips. The U-shaped clips are staggered along the height of the frame, with adjacent clips facing opposite directions to distribute connection stress and enhance overall stability. The bottom anchoring beams 6 and rear support columns 7 are drilled with holes at intervals of ≤500mm to accommodate anchor expansion bolts, with an anchoring depth of ≥300mm to ensure the stability of the formwork under complex terrain conditions.

[0040] The riverbed is generally uneven, so before installing the first layer of triangular prism frame, the bottom needs to be leveled using formwork concrete. The formwork dimensions are 0.3m × 0.3m × 0.2m, and the material is 450g / m³. 2High-strength woven polypropylene fabric with a longitudinal tensile strength of 80kN / m, a transverse tensile strength of 60kN / m, and an elongation of 30%. The formwork bags are filled with dry-mixed mortar of the same grade as the concrete, with 3% of the cement content added as an expansion agent to compensate for setting shrinkage and prevent voids. During construction, divers lay the formwork bags in alternating layers along the water flow direction and shoreline, using tools to press them tightly against the riverbed, with an overlap of ≥10cm between adjacent bags. After laying the formwork bags, the maximum gap between the bottom surface and the riverbed surface should not exceed 50mm to ensure leveling. The first layer of formwork is installed 7 days after the concrete in the formwork bags has solidified to form a flat base.

[0041] Secure the formwork lifting rings with wire ropes, and after the truck crane slowly lifts it into the water, divers adjust the verticality to assist in positioning. Divers use Φ12mm U-shaped clips to connect and fix adjacent formwork sections, assembling the formwork into a whole. During installation, the clips are staggered, one facing forward and one backward. Anchor expansion bolts pass through the pre-drilled holes in the front support column 4, the bottom anchor beam 6, and the rear support column 7, anchoring the triangular prism frame 1 to the base structure. The formwork concrete bag 3 has external dimensions of 0.3×0.3×0.2 meters and is made of high-strength woven polypropylene fabric, providing a solid, flat, and sealed installation foundation for the first layer of formwork, effectively preventing grout leakage or foundation hole formation during pouring.

[0042] The pouring height is consistent with the formwork height (3m / layer). Underwater tremie pipe pouring is used for self-compacting, non-dispersible concrete. The tremie pipe depth is controlled at 1-2m, and the concrete rising speed is ≤0.5m / h to ensure full filling of the self-compacting concrete. No vibration is required; the permeable panels automatically drain internal water and air. The galvanized steel wire mesh 11 in the permeable panels works synergistically with the permeable formwork fabric 12 for concrete engineering to drain internal moisture and air from the concrete, preventing air bubble accumulation and cement paste loss. This results in a dense, hardened layer on the concrete surface, significantly improving the concrete's compressive strength and durability.

[0043] The following quality control points must be strictly controlled during construction:

[0044] 1. The overlap width between the galvanized steel wire mesh 11 and the permeable formwork fabric 12 for concrete engineering shall not be less than 15cm, and shall be fixed by double-strand binding wire at intervals to prevent grout leakage;

[0045] 2. After the concrete leveling blocks are laid, the maximum gap between the bottom surface and the riverbed surface should not exceed 50mm;

[0046] 3. The allowable deviation of verticality after template assembly shall not exceed 1% of the template height, and the allowable deviation of planar position shall not exceed 30mm;

[0047] 4. The bottom of the formwork panel extends towards the backwater side to form a reverse edge, preventing grout leakage during the pouring process;

[0048] 5. The overall shear strength of the assembled template must meet the design requirements to ensure structural stability.

[0049] Durability protection measures: The surface of the template frame is sandblasted to Sa2.5 standard, with a roughness controlled within the range of 50-80μm, and then coated with two coats of epoxy zinc-rich primer, with a dry film thickness ≥120μm, to enhance underwater corrosion resistance. Reinforcing steel bars are epoxy-coated steel bars with a coating thickness of 200-300μm and a pinhole count ≤1 / m. 2 The adhesion is ≥70MPa. The permeable template fabric adopts a composite structure of polyester filament nonwoven fabric and polyvinyl chloride coating, with a base fabric weight ≥200g / m². 2 The PVC coating thickness is ≥0.15mm, and the tensile strength retention rate after UV aging test is ≥88%, and the elongation attenuation is ≤10%, meeting the requirements for long-term use.

[0050] Example Verification: This utility model template was applied in a riverbank protection project with a construction water depth of 5-8m, a riverbed slope of 1:0.5, a riverbed rock surface undulation of up to 2m, and a flow velocity of 1.2m / s. Compared with traditional steel templates, construction efficiency was increased by 60% (single template assembly time reduced from 4 hours to 1.5 hours), the honeycomb surface pitting rate of concrete decreased from 12% to 2%, the compressive strength compliance rate reached 100%, the formwork removal process was saved, no underwater safety accidents occurred, and the overall cost was reduced by 35%. After completion, the project withstood three floods (peak flow velocity 3.0m / s) without structural damage. Through practical application verification, this utility model template demonstrates significant advantages in construction efficiency, concrete quality, cost control, and structural durability, fully meeting the construction needs of deep water areas, high flow velocities, and complex terrain conditions.

[0051] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A permeable underwater concrete formwork that requires no dismantling and can be assembled, characterized in that: It includes a triangular prism frame (1), multiple reinforcing steel bars set in the triangular prism frame (1), and a permeable panel set on the triangular prism frame (1). The permeable panel includes a grid support frame (10), a galvanized steel wire mesh (11), and a permeable formwork fabric (12) for concrete engineering, which are attached in sequence. The grid support frame (10) is welded to the inner corner of the triangular prism frame (1). The galvanized steel wire mesh (11) is tied to the back surface of the grid support frame (10). The permeable formwork fabric (12) for concrete engineering is lined to the back surface of the galvanized steel wire mesh (11), and the bottom extends towards the back surface to form a reverse edge. Multiple triangular prism frames (1) are provided, and adjacent triangular prism frames (1) are assembled and connected by connectors, and the bottom is anchored to the base structure by fasteners.

2. The underwater concrete non-removable assembly permeable formwork according to claim 1, characterized in that: The triangular prism frame (1) is composed of a front support column (4), a side connecting beam (5), a bottom anchor beam (6), and a rear support column (7). Two front support columns (4) and one rear support column (7) are arranged in parallel to form the three longitudinal sides of the triangular prism. The ends of the two side connecting beams (5) and the bottom anchor beam (6) are welded together to form a triangular planar frame. The two sets of triangular planar frames serve as the two end faces of the triangular prism, and their apex angles are welded to the upper and lower ends of the three support columns to form a closed frame structure. Adjacent triangular prism frames (1) are assembled and connected by connectors on the side connecting beams (5) and the bottom anchor beams (6). The front support column (4), the side connecting beams (5), the bottom anchor beams (6), and the rear support column (7) are all angle steel with the inside corners facing inward.

3. The underwater concrete non-removable assembly permeable formwork according to claim 2, characterized in that: The reinforcing steel bars include bottom cross steel bars (8) and side diagonal steel bars (9); the bottom cross steel bars (8) are arranged in the quadrilateral plane formed by the front support column (4), the bottom anchor beam (6) and the rear support column (7), and are distributed in an X-shape along the diagonal of the quadrilateral plane; the side diagonal steel bars (9) are symmetrically arranged in the triangular plane frame on the left and right sides, and their two ends are respectively welded to one of the side connecting beams (5) and the bottom anchor beam (6). Four side diagonal steel bars (9) are arranged parallel and inclined in one side of the triangular plane frame, and the four side diagonal steel bars (9) are distributed at equal intervals along the length direction of the bottom anchor beam (6); the reinforcing steel bars are made of threaded steel.

4. The underwater concrete non-removable assembly permeable formwork according to claim 1, characterized in that: The grid support frame (10) is made of threaded steel bars with a diameter of 19-21 mm welded to the inner corner of the triangular prism frame (1). The horizontal spacing of the threaded steel bars is 19-21 cm and the vertical spacing is 29-31 cm.

5. The underwater concrete non-removable assembly permeable formwork according to claim 4, characterized in that: The galvanized steel wire mesh (11) has a wire diameter of 0.5-0.7 mm and a mesh size of 3×3 mm. It is tied to the back surface of the mesh support frame (10) with double-strand tie wire. The tying points are distributed along the nodes of the threaded steel bars. The overlap width of adjacent galvanized steel wire mesh (11) is ≥15 cm.

6. The underwater concrete non-removable assembly permeable formwork according to claim 5, characterized in that: The permeable formwork fabric (12) for concrete engineering is 1-3 mm thick and made of polypropylene fiber. It is pasted onto the back side of the galvanized steel wire mesh (11). The bottom of the permeable formwork fabric (12) extends 10-14 cm towards the back side to form a reverse edge structure. The permeability coefficient of the permeable formwork fabric (12) for concrete engineering is ≥0.4×10⁻⁶. -3 cm / s, longitudinal tensile strength ≥80kN / m.

7. The underwater concrete non-removable assembly permeable formwork according to claim 1, characterized in that: The connector is a U-shaped buckle, which is staggered along the height of the triangular prism frame (1), with adjacent U-shaped buckles facing opposite directions.

8. The underwater concrete non-removable assembly permeable formwork according to claim 1, characterized in that: The fastener is an anchor expansion bolt, and the anchoring depth of the anchor expansion bolt is ≥300 mm. The anchor expansion bolt passes through the preset holes of the front support column (4), the bottom anchor beam (6) and the rear support column (7) respectively, and anchors the triangular prism frame (1) to the base structure.

9. The underwater concrete non-removable assembly permeable formwork according to claim 1, characterized in that: The triangular prism frame (1) has multiple layers. The bottom of the first layer of the triangular prism frame is leveled with molded concrete (3). The external dimensions of the molded concrete (3) are 0.3×0.3×0.2 meters, and the material is high-strength woven polypropylene cloth.

10. The underwater concrete non-removable assembly permeable formwork according to claim 2, characterized in that: It also includes a non-standard component frame (2); the non-standard component frame (2) is set according to the requirements of the corner or irregular part of the project. Its structural form is adapted to the triangular prism frame (1). It is assembled and connected with the adjacent triangular prism frame (1) or other non-standard component frames (2) through connectors, and is anchored to the base structure through fasteners to adapt to the construction requirements of complex geometry.

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