A method for reinforcing the formwork of a caisson cutting edge

Abstract

This invention relates to the field of caisson construction technology and discloses a method for reinforcing the formwork of the cutting edge of a caisson, comprising the following steps: S1, construction preparation: according to the caisson design drawings, the diagonal bracing at the inner chamfer of the cutting edge is refined, fabricated in sections, and conventional materials are prepared; S2, foundation layer construction: first, the positioning lines of the foundation layer and the positioning holes of the diagonal bracing are located on the construction site. After the bearing capacity and flatness meet the requirements, the foundation layer is constructed; S3, diagonal bracing installation; S4, reinforcement and formwork installation; S5, concrete pouring and curing; S6, formwork removal and diagonal bracing removal. Using multi-layer bamboo plywood as formwork provides a smooth surface, light weight, and easy handling and installation, improving appearance quality and reducing labor intensity. Furthermore, after shaping, it conforms to the shape of the caisson, preventing grout leakage. The staggered joints allow the formwork to interlock, enabling coordinated stress distribution during pouring, enhancing the stability of the formwork system, reducing deformation, and ensuring the quality of concrete pouring and construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of caisson construction technology, specifically a method for reinforcing the cutting edge formwork of a caisson. Background Technology

[0002] In caisson construction, the reinforcement of the formwork at the cutting edge is extremely critical. As a special underground structure, the cutting edge of the caisson must withstand the large lateral pressure and vertical load from the soil. It is the cornerstone for ensuring the stability and accuracy of the caisson structure. A stable formwork can effectively resist the huge pressure and lateral force during concrete pouring, prevent the formwork from deforming or shifting, and thus ensure that the dimensions of the caisson cutting edge are accurate, the shape is regular, and it meets the design requirements. In the current caisson construction process, the installation of the cutting edge formwork usually adopts techniques such as brick formwork masonry and formwork block assembly.

[0003] However, current technology suffers from problems such as low formwork turnover rate during caisson construction, and long construction cycles for brick formwork and mortar strength to reach design requirements. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for reinforcing the formwork of caisson cutting edges, solving the problems of low formwork turnover rate, long brick formwork construction cycle, and long cycle for mortar strength to reach design requirements.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for reinforcing the formwork of a caisson cutting edge, comprising the following steps:

[0006] S1. Construction preparation: According to the caisson design drawings, the inclined support body at the inner chamfer of the cutting edge is further refined, and it is manufactured in sections and conventional materials are prepared.

[0007] S2. Subbase construction: First, locate the subbase edge line and the positioning holes of the inclined bracing on the construction site. After the bearing capacity and flatness meet the requirements, the subbase construction will proceed.

[0008] S3. Installation of diagonal bracing: Locate the inner and outer edges of the caisson cutting edge, then install the diagonal bracing piece by piece according to the positioning lines, and fill the contact surface between the diagonal bracing and the caisson pad layer with thick sponge double-sided tape.

[0009] S4. Reinforcing steel and formwork installation: Multi-layer bamboo plywood is used for the formwork. It is shaped and processed according to the inner and outer wall dimensions and curvature of the caisson. The square caisson side wall formwork is assembled by staggered splicing of upper and lower layers.

[0010] S5. Concrete pouring and curing: Before pouring concrete, check the centerline position of the caisson and the reserved and embedded positions, and inspect the reinforcement and joints of the formwork, remove debris, and then use an immersion vibrator to assist in the concrete pouring. After pouring, curing is carried out.

[0011] S6. Formwork and diagonal bracing removal: Conduct a pressure test. When the concrete strength reaches 2.5MPa, remove the side formwork that does not bear the weight of the concrete. When the concrete reaches 75% of the design strength, remove the formwork and diagonal bracing or pour the next section of concrete.

[0012] Preferably, the inclined support in S1 includes an outer steel plate, an inner high-strength polystyrene filler, and a positioning rod. The positioning rod is used to position the plain round steel bars welded under the inclined support, and the welding angle is consistent with the angle of the inclined support. The groove of the caisson bottom plate uses a straight support including an outer bamboo plywood, an inner high-strength polystyrene filler, and is fixed to the inner template with screws. The conventional materials include templates, three-section tie bolts, plain round steel bars, steel pipes, and auxiliary materials required for construction.

[0013] Preferably, the positioning hole in S2 is a pre-embedded PVC pipe pre-reserved hole, and the construction width of the cushion layer is 50cm on each side of the well wall, and the thickness is 25-30cm.

[0014] Preferably, when installing the positioning rod in the diagonal brace of S3, the sponge double-sided tape is fully wrapped around it, the diagonal brace 1 is filled with 1mm-2mm thick sponge double-sided tape, the thickness of the sponge double-sided tape between the diagonal brace and the caisson pad layer is 2-3mm, the diagonal brace and the tie bolt contact point are made of detachable tie bolts, and the contact point is sealed with waterproof tape.

[0015] Preferably, the steps for installing reinforcing bars and formwork in S4 include:

[0016] S01. Install the inner template of the caisson and the straight support at the groove of the bottom plate, and apply release agent;

[0017] S02. Install the wedge at the bottom of the cutting edge and the reinforcing bar at the bottom of the cutting edge;

[0018] S03. The bottom wedge of the cutting edge is welded and fixed to the bottom steel bar;

[0019] S04. Continue tying the upper reinforcing bars to the height required for the first pouring;

[0020] S05. Install the outer template and apply release agent, install tie rods and protective layer pads, and the tie rod spacing, main and secondary rib spacing and specifications need to be determined according to the design calculation;

[0021] S06. Conduct a comprehensive inspection and acceptance of the template installation quality.

[0022] Preferably, in step S5, the concrete pouring is carried out according to the principle of "from low to high, symmetrical layering", with the layer thickness controlled at about 30cm. The displacement spacing of the immersion vibrator does not exceed 1.5 times the effective radius of the vibrator, and it maintains a distance of 5-10cm from the side formwork. The depth of insertion into the lower layer of concrete is 5-10cm, and the vibration duration of each vibration point is 20-30s. After the concrete pouring is completed, curing is carried out in a timely manner. The curing is carried out by moist curing at 15-35℃ and by heat preservation curing at -5-15℃.

[0023] Preferably, the concrete strength in S6 is determined by both rebound testing and test block strength testing. The diagonal brace is removed after its bottom surface is pried open with a crowbar. The template and the straight brace are fixed and not removed. Cleaning and maintenance are carried out after the template, diagonal brace and straight brace are removed.

[0024] This invention provides a method for reinforcing the formwork of the cutting edge of a caisson. It has the following beneficial effects:

[0025] 1. This invention uses multi-layer bamboo plywood as templates, which has a smooth surface, is lightweight, and is easy to handle and install. It can improve the appearance quality and reduce labor intensity. At the same time, after shaping, it can match the shape of the caisson, prevent grout leakage, and the staggered splicing makes the templates interlock, so that they can share the force during pouring, enhance the stability of the template system, reduce deformation, and ensure the quality of concrete pouring and construction efficiency.

[0026] 2. The positioning rods of the inclined bracing body of this invention are fully wrapped with double-sided sponge tape. At the same time, the surfaces between the inclined bracing bodies and the contact surfaces with the padding layer are filled with double-sided sponge tape of a specific thickness. This can effectively fill the gaps, prevent grout leakage during concrete pouring, and ensure the quality of concrete pouring and structural integrity. Furthermore, the disconnectable tie bolts and waterproof tape sealing treatment at the contact points with the inclined bracing body achieve effective support for the formwork, ensuring the stability and waterproofness of the connections of various components during construction, and ensuring the smooth progress of caisson construction and structural quality.

[0027] 3. This invention uses a low-to-high, symmetrical layering principle and controls the layer thickness to pour concrete, which allows the concrete to rise evenly and be under balanced stress, avoiding deformation of the formwork due to uneven stress, ensuring the quality of the caisson structure. In addition, by using an immersion vibrator with adjustable displacement spacing, distance from the side formwork, insertion depth into the lower layer, and vibration duration, the concrete can be fully vibrated, expelling air and air bubbles, making it dense and free of voids, and improving strength and durability. Attached Figure Description

[0028] Figure 1 This is a flowchart of a construction method for reinforcing the cutting edge formwork of a caisson according to the present invention;

[0029] Figure 2 This is a flowchart illustrating the reinforcement and formwork installation steps of a caisson cutting edge formwork reinforcement construction method according to the present invention.

[0030] Figure 3 This is a schematic diagram of the installation of the inclined support body in a method for reinforcing the formwork of a caisson cutting edge according to the present invention;

[0031] Figure 4 This is a schematic diagram of the formwork installation for a method of reinforcing the cutting edge formwork of a caisson according to the present invention;

[0032] Figure 5 This is a schematic diagram of the casting and molding process of a caisson cutting edge template reinforcement construction method according to the present invention.

[0033] Figure 6 This is a partial structural diagram of the inclined support body in a method for reinforcing the formwork of a caisson cutting edge according to the present invention.

[0034] Among them, 1. diagonal bracing; 11. steel plate; 12. polystyrene filler; 13. positioning rod; 2. padding layer; 3. template. Detailed Implementation

[0035] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please see the appendix Figure 1 - Appendix Figure 6 This invention provides a method for reinforcing the formwork of a caisson cutting edge, comprising the following steps:

[0037] S1. Construction preparation: According to the caisson design drawings, the inclined support body 1 at the inner chamfer of the cutting edge is further developed, and it is manufactured in sections and conventional materials are prepared.

[0038] S2, Subbase 2 Construction: First, locate the edge line of subbase 2 and the positioning holes of the inclined brace 1 on the construction site. After the bearing capacity and flatness meet the requirements, subbase 2 construction will proceed.

[0039] S3. Installation of diagonal bracing 1: Locate the inner and outer edges of the caisson cutting edge, then install the diagonal bracing 1 piece by piece according to the positioning lines, and fill the contact surface between the diagonal bracing and the caisson pad layer 2 with thick sponge double-sided tape.

[0040] S4. Reinforcing steel and formwork 3 installation: Formwork 3 is made of multi-layer bamboo plywood, which is shaped and processed according to the inner and outer wall dimensions and curvature of the caisson. The square caisson side wall formwork 3 is assembled by staggered splicing of upper and lower layers.

[0041] S5. Concrete pouring and curing: Before pouring concrete, check the centerline position of the caisson and the reserved and embedded positions, and inspect the reinforcement and joints of formwork 3, remove debris, and then use an immersion vibrator to assist in the concrete pouring, and carry out curing after the pouring is completed.

[0042] S6. Removal of Formwork 3 and Diagonal Bracing: Conduct a pressure test. When the concrete strength reaches 2.5MPa, remove the side formwork that does not bear the weight of the concrete. When the concrete reaches 75% of the design strength, remove Formwork 3 and Diagonal Bracing or pour the next section of concrete.

[0043] Specifically, through detailed design in S1, the shape and size of the outer steel plate 11 of the diagonal brace 1 can be precisely designed according to the specific shape, size and stress characteristics of the inner chamfer of the caisson cutting edge, so that it fits perfectly with the chamfer, thereby achieving the best support effect, effectively preventing the cutting edge formwork 3 from deforming during the concrete pouring process, and ensuring the structural accuracy of the caisson cutting edge.

[0044] The edge line of the positioning pad 2 in S2 can determine the accurate position of the caisson on the construction site, providing a benchmark for the subsequent construction of the caisson, ensuring that the position of the caisson meets the design requirements, and avoiding positional deviations that affect the layout and functionality of the entire project. The accurate pre-reservation of the positioning holes of the inclined brace 1 ensures the accurate installation of the inclined brace 1, enabling the inclined brace 1 to be installed according to the design position, thereby effectively playing its supporting role on the cutting edge template 3, ensuring the positional accuracy of the cutting edge template 3, and thus ensuring that the shape and size of the caisson cutting edge meet the design requirements.

[0045] The S3 section accurately positions the inner and outer edges of the caisson cutting edge, providing a precise benchmark for the installation of the diagonal bracing. This ensures the accurate position of the bracing within the caisson structure, providing stable and reliable support for the entire cutting edge formwork 3 reinforcement system. Installing the diagonal bracing piece by piece allows for more precise control over the position and angle of each bracing piece, better adapting to the shape changes at the inner chamfer of the cutting edge. Compared to overall installation, this effectively avoids installation errors caused by the larger overall size, further improving the support accuracy of the diagonal bracing 1 for the cutting edge formwork 3. This ensures that the cutting edge formwork 3 receives uniform and stable support in all areas. Simultaneously, using double-sided adhesive sponge to fill the contact surfaces effectively seals these gaps, preventing concrete slurry seepage and ensuring that the concrete is evenly distributed within the formwork 3. This guarantees the quality of concrete pouring and makes the concrete structure at the caisson cutting edge more compact and complete.

[0046] In S4, formwork 3 is made of multi-layer bamboo plywood. Its smooth surface makes the concrete surface clean, reduces defects, and improves appearance quality. It is also lightweight, easily deformable, and convenient for handling and installation, improving construction efficiency and reducing labor intensity. Furthermore, the inner and outer walls of the caisson typically have specific dimensional and curvature requirements. By shaping the multi-layer bamboo plywood, it can perfectly match the actual shape of the caisson. This ensures a tight fit between formwork 3 and the caisson structure during installation, leaving no gaps. This effectively prevents grout leakage during concrete pouring, guaranteeing the quality of concrete pouring and the compactness of the caisson structure. Simultaneously, the staggered splicing method allows the upper and lower layers of formwork 3 to interlock, forming a unified formwork 3 structure. This allows formwork 3 to better cooperate in bearing the load during subsequent concrete pouring, jointly resisting the lateral pressure generated by the concrete, enhancing the overall stability of the formwork 3 system, and reducing the possibility of formwork 3 deformation.

[0047] In S5, verifying the centerline position of the caisson and the reserved and embedded positions ensures the accuracy of the structural position and smooth subsequent connection. Checking the reinforcement and joints of formwork 3 and cleaning debris can maintain the stability of formwork 3, prevent grout leakage and debris mixing. Using an immersion vibrator for pouring can make the concrete dense and uniform. Post-pouring curing can prevent cracking, improve strength and durability, thereby ensuring the quality of caisson concrete pouring, structural stability and meeting design and usage requirements from multiple aspects, and extending its service life.

[0048] The pressure test conducted in S6 can detect whether the performance and stability of the caisson structure meet the standards. When the concrete strength reaches 2.5MPa, the non-weight-bearing side formwork is removed, which can ensure that the concrete has a certain degree of self-stability at this time, and facilitate subsequent construction operations and quality inspection. When the strength reaches 75%, the formwork 3 and the diagonal bracing are removed or the next section of concrete is poured, because the concrete can withstand a greater load at this time. The removal operation will not affect the structural safety, and can be flexibly arranged according to the project progress, ensuring the continuity of construction and the overall structural quality of the caisson.

[0049] S1 The inclined brace 1 includes an outer steel plate 11, an inner high-strength polystyrene filler 12 and a positioning rod 13. The positioning rod is used to position the plain round steel bars welded under the inclined brace 1. The welding angle is consistent with the angle of the inclined brace. The groove of the caisson bottom plate adopts a straight brace including an outer bamboo plywood, an inner high-strength polystyrene filler 12, and is fixed to the inner template 3 with screws. The conventional materials include template 3, three-section tie bolts, plain round steel bars and steel pipes, and auxiliary materials required for construction.

[0050] Specifically, the inclined bracing 1 works in conjunction with the straight bracing and conventional materials. The external steel plate 11, internal filling material, and positioning rod 13 of the inclined bracing 1 work together to accurately position and effectively support the cutting edge template 3, resisting the pressure and deformation during concrete pouring. The bamboo plywood and filling material of the straight bracing are fixed to the inner template 3 with screws to stabilize the shape of the inner template 3. The template 3 in the conventional materials constructs the pouring shape. Tie bolts, plain round steel bars, and steel pipes reinforce the template 3 system. Auxiliary materials ensure smooth construction and together provide stable and reliable structural support and construction conditions for the caisson construction, ensuring the accuracy of the caisson structure and the construction quality.

[0051] Specifically, pre-embedded PVC pipes with reserved positioning holes are used to provide accurate reference for the precise installation of the diagonal brace 1, ensuring that its position and angle meet the design requirements and effectively play its supporting role. During the construction of the foundation layer 2, the width of each side of the well wall is increased by 50cm and the thickness is increased to 25-30cm. This not only expands the bearing area so that the load of the caisson can be evenly distributed to the foundation and prevent uneven settlement of the foundation, but also provides a flat, stable foundation platform with sufficient operating space for the subsequent construction of the cutting edge formwork 3 and related structures, ensuring construction accuracy and structural stability.

[0052] When installing the positioning rod 13 in the diagonal brace 1 of S3, the rod is fully wrapped with double-sided sponge tape. The space between the diagonal brace 1 and the diagonal brace is filled with 1mm-2mm thick double-sided sponge tape. The thickness of the double-sided sponge tape between the diagonal brace and the caisson pad 2 is 2-3mm. The contact point between the diagonal brace and the tie bolt is a disconnectable tie bolt, and the contact point is sealed with waterproof tape.

[0053] Specifically, the positioning rod 13 of the diagonal brace 1 is fully wrapped with double-sided sponge tape, and the contact surfaces between the diagonal braces and the padding layer 2 are filled with double-sided sponge tape of a specific thickness. This effectively fills the gaps and prevents grout leakage during concrete pouring, which would prevent the subsequent diagonal braces from being disassembled. This ensures the quality of concrete pouring and the integrity of the structure. The disconnectable tie bolts and the waterproof tape sealing treatment at the contact points with the diagonal braces not only achieve effective fastening and support of the tie bolts to the formwork 3, but also facilitate the subsequent disassembly of the diagonal braces, reducing damage to the structure and materials. At the same time, it ensures the stability and waterproofness of the connections of various components during construction, ensuring the smooth progress of the caisson construction and the quality of the structure.

[0054] The steps for installing reinforcing bars and formwork 3 in S4 include:

[0055] S01. Install the inner template 3 of the caisson and the straight support at the groove of the bottom plate, and apply release agent;

[0056] S02. Install the wedge at the bottom of the cutting edge and the reinforcing bar at the bottom of the cutting edge;

[0057] S03. The bottom wedge of the cutting edge is welded and fixed to the bottom steel bar;

[0058] S04. Continue tying the upper reinforcing bars to the height required for the first pouring;

[0059] S05. Install the outer template 3 and apply the release agent. Install the tie rods and protective layer pads. The tie rod spacing, main and secondary rib spacing and specifications need to be determined according to the design calculation.

[0060] S06. Conduct a comprehensive inspection and acceptance of the installation quality of template 3.

[0061] Specifically, the process begins with installing the inner formwork 3 and its upright supports, followed by applying a release agent. This facilitates subsequent concrete demolding and ensures the stability of the inner formwork 3's shape. Next, the bottom inclined iron and reinforcing bars of the cutting edge are installed and welded in place, providing a stable foundation for the cutting edge and enhancing the overall structural integrity. Then, the upper reinforcing bars are tied to the specified height, constructing the steel reinforcement framework of the caisson to bear the load. Afterward, the outer formwork 3, tie rods, and protective layer pads are installed to ensure the accurate and stable positioning of the outer formwork 3. Controlling the spacing and specifications of the formwork 3 effectively resists the lateral pressure of the concrete, ensuring the stability and reliability of the formwork 3 system. Finally, a comprehensive inspection and acceptance process allows for the timely detection and correction of any problems in the installation of the formwork 3, ensuring that the caisson's reinforcing bars and formwork 3 installation meet design requirements. This lays a solid foundation for subsequent concrete pouring, ensuring the quality of the caisson structure and construction safety.

[0062] In S5, concrete pouring is carried out according to the principle of "from low to high, symmetrical layering". The layer thickness is controlled at about 30cm. The displacement spacing of the immersion vibrator does not exceed 1.5 times the effective radius of the vibrator. It is kept 5-10cm away from the side formwork. The depth of insertion into the lower layer of concrete is 5-10cm. The vibration time of each vibration point is 20-30s. After the concrete is poured, it is cured in time. Curing is carried out by moist curing at 15-35℃ and thermal curing at -5-15℃.

[0063] Specifically, following the principle of "from low to high, symmetrical layering" and controlling the layer thickness to approximately 30cm, the concrete is poured to ensure uniform rise and balanced stress, preventing deformation of formwork 3 due to uneven stress and guaranteeing the quality of the caisson structure. Furthermore, specifying the displacement spacing of the immersion vibrator, its distance from the side formwork, its insertion depth into the lower layer, and the vibration duration ensures thorough compaction of the concrete, expelling air and bubbles, resulting in a dense, void-free structure that enhances strength and durability. After pouring, timely curing is crucial. Moisturizing at 15-35℃ prevents excessive surface moisture evaporation and cracking, while thermal insulation at -5-15℃ reduces temperature stress and prevents cracking, providing a suitable environment for concrete hardening, ensuring normal strength growth and structural stability, and meeting the design requirements and performance of the caisson.

[0064] The concrete strength in S6 is determined by a combination of rebound testing and test block strength testing. The diagonal brace 1 is removed after its bottom surface is pried off with a crowbar. The formwork 3 is fixed to the straight brace and is not removed. Cleaning and maintenance are carried out after the formwork 3, diagonal brace and straight brace are removed.

[0065] Specifically, the concrete strength is determined through rebound testing and test block strength tests, which allows for precise control of the actual concrete strength. This provides a scientific basis for the timing of removing formwork 3 and the diagonal bracing, ensuring safe removal operations without affecting the stability of the caisson structure. Furthermore, the diagonal bracing 1, thanks to the specific design angle of the positioning rod 13, can be easily removed from its bottom surface using a small pry bar after the concrete reaches the required strength. This reduces the difficulty of removal and minimizes damage to the caisson structure and surrounding concrete, ensuring structural integrity. Afterward, formwork 3 and the vertical bracing are fixed but not removed immediately, which helps maintain the integrity and stability of the caisson structure during subsequent construction. Finally, cleaning and maintenance after removal remove debris, inspect components, extend the service life of formwork 3, the diagonal bracing, and the vertical bracing, and provide reusable high-quality materials for similar projects. This also ensures the entire caisson construction process is orderly and standardized, guaranteeing project quality and reducing costs.

[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for reinforcing the formwork of a caisson cutting edge, characterized in that, Includes the following steps: S1. Construction preparation: According to the caisson design drawings, the inclined support body at the inner chamfer of the cutting edge is further refined, and it is manufactured in sections and conventional materials are prepared. S2. Subbase construction: First, locate the subbase edge line and the positioning holes of the inclined bracing on the construction site. After the bearing capacity and flatness meet the requirements, the subbase construction will proceed. S3. Installation of diagonal bracing: Locate the inner and outer edges of the caisson cutting edge, then install the diagonal bracing piece by piece according to the positioning lines, and fill the contact surface between the diagonal bracing and the caisson pad layer with thick sponge double-sided tape. S4. Reinforcing steel and formwork installation: Multi-layer bamboo plywood is used for the formwork. It is shaped and processed according to the inner and outer wall dimensions and curvature of the caisson. The square caisson side wall formwork is assembled by staggered splicing of upper and lower layers. S5. Concrete pouring and curing: Before pouring concrete, check the centerline position of the caisson and the reserved and embedded positions, and inspect the reinforcement and joints of the formwork, remove debris, and then use an immersion vibrator to assist in the concrete pouring. After pouring, curing is carried out. S6. Formwork and diagonal bracing removal: Conduct a pressure test. When the concrete strength reaches 2.5MPa, remove the side formwork that does not bear the weight of the concrete. When the concrete reaches 75% of the design strength, remove the formwork and diagonal bracing or pour the next section of concrete. The inclined support in S1 includes an outer steel plate, an inner high-strength polystyrene filler and a positioning rod. The positioning rod is a plain round steel bar welded to the underside of the inclined support, and the welding angle is consistent with the angle of the inclined support. The groove of the caisson bottom plate uses a straight support body including an outer bamboo plywood, an inner high-strength polystyrene filler, and is fixed to the inner template with screws. The conventional materials include templates, three-section tie bolts, plain round steel bars and steel pipes. When installing the positioning rod in the inclined brace of S3, the sponge double-sided tape is fully wrapped. The space between the inclined braces is filled with 1mm-2mm thick sponge double-sided tape. The thickness of the sponge double-sided tape between the inclined brace and the caisson pad layer is 2-3mm. The contact point between the inclined brace and the tie bolt is a disconnectable tie bolt, and the contact point is sealed with waterproof tape.

2. The method for reinforcing the formwork of the caisson cutting edge according to claim 1, characterized in that, The positioning hole in S2 is a pre-embedded PVC pipe with a reserved hole. The construction width of the cushion layer is 50cm on each side of the well wall, and the thickness is 25-30cm.

3. The method for reinforcing the formwork of the caisson cutting edge according to claim 1, characterized in that, The steps for installing reinforcing bars and formwork in S4 include: S01. Install the inner template of the caisson and the straight support at the groove of the bottom plate, and apply release agent; S02. Install the wedge at the bottom of the cutting edge and the reinforcing bar at the bottom of the cutting edge; S03. The bottom wedge of the cutting edge is welded and fixed to the bottom steel bar; S04. Continue tying the upper reinforcing bars to the height required for the first pouring; S05. Install the outer template and apply release agent, install tie rods and protective layer pads, and the tie rod spacing, main and secondary rib spacing and specifications need to be determined according to the design calculation; S06. Conduct a comprehensive inspection and acceptance of the template installation quality.

4. The method for reinforcing the formwork of the caisson cutting edge according to claim 1, characterized in that, In S5, the concrete pouring is carried out according to the principle of "from low to high, symmetrical layering". The layer thickness is controlled at about 30cm. The displacement distance of the immersion vibrator does not exceed 1.5 times the effective radius of the vibrator. It maintains a distance of 5-10cm from the side formwork and is inserted into the lower layer of concrete to a depth of 5-10cm. The vibration time of each vibration point is 20-30s. After the concrete pouring is completed, it is cured in time. The curing is carried out by moist curing at 15-35℃ and thermal curing at -5-15℃.

5. The method for reinforcing the formwork of the caisson cutting edge according to claim 1, characterized in that, The concrete strength in S6 is determined by a combination of rebound testing and test block strength testing. The diagonal brace is removed after its bottom surface is pried open with a crowbar. The template and the straight brace are fixed and not removed. Cleaning and maintenance are carried out after the template, diagonal brace and straight brace are removed.

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