Cast-in-place open caisson formwork supporting structure and construction method thereof

Abstract

The invention relates to a cast-in-place open caisson formwork supporting structure and a construction method thereof.The structure comprises a lower-section well wall, a reinforcing mesh and a plurality of embedded supporting ribs arranged in the circumferential direction of the lower-section well wall, and the reinforcing mesh is embedded in the lower-section well wall, partially extends out of the top face of the lower-section well wall and is located between formwork units on the two sides; each pre-embedded supporting rib is embedded in the lower-section well wall and partially extends out of the side surface of the lower-section well wall; the formwork units are arranged on the two opposite sides of the lower-section well wall in the circumferential direction of the lower-section well wall and erected on the portions, extending out of the lower-section well wall, of the embedded supporting ribs; the first tying pieces are used for tying the bottoms of the formwork units and the reinforcing mesh; and the plurality of second tying pieces are used for tying the tops of the two symmetrically arranged template units. The existing reinforcing mesh in the open caisson structure is fully used as a tie anchoring point, the pre-embedded supporting rib is used as a bottom support of the formwork unit, the first tie piece and the second tie piece are used for restraining the bottom and the top of the formwork unit respectively, a stable supporting system is formed, the structure is simple, installation is fast, and the construction cost is low.

Description

Technical Field

[0001] This specification relates to the field of building construction technology, and in particular to a cast-in-place caisson formwork support structure and its construction method. Background Technology

[0002] A caisson is a reinforced concrete underground structure. Cast-in-place caissons are constructed and sunk in sections on the ground. The construction process for each section involves reinforcing steel binding, formwork installation and fixing, concrete pouring and curing. After pouring to a certain height, soil is excavated at the bottom of the caisson, allowing it to sink under its own weight. The reinforced concrete structure is then rejoined, and this process of excavation and sinking is repeated until the caisson reaches the design elevation. Since concrete is poured at least 50cm above ground level, formwork of a certain thickness and height is required. Because the top of the already poured lower caisson wall is generally more than 50cm above ground, there are no support points at the bottom of the formwork when pouring the upper caisson wall. Therefore, establishing a formwork support and reinforcement system is crucial for the successful formation of the cast-in-place caisson.

[0003] The existing formwork support for concrete pouring of caissons, shear walls, retaining walls, pool walls, well walls, etc., often adopts the screw rod method, which uses tie rods to tighten and fix the formwork on both the inner and outer sides. Vertical timber and horizontal steel pipe support skeletons are set on the outer side of the formwork on both sides of the structural wall to form a formwork support and reinforcement system for concrete pouring. This construction method has a long construction period and high cost. Summary of the Invention

[0004] This specification provides a cast-in-place caisson formwork support structure and its construction method, which solves the problems of long construction cycle and high cost of concrete casting formwork support structures in the prior art.

[0005] The following technical solution is adopted in this specification: A cast-in-place caisson formwork support structure includes a lower section of the caisson wall, and further includes: a steel mesh and a plurality of pre-embedded support bars arranged circumferentially along the lower section of the caisson wall, wherein the steel mesh is embedded in the lower section of the caisson wall and partially extends out of the top surface of the lower section of the caisson wall; each of the pre-embedded support bars is embedded in the lower section of the caisson wall and partially extends out of the side surface of the lower section of the caisson wall; formwork units are arranged circumferentially along the lower section of the caisson wall on opposite sides and are supported on the portions of the pre-embedded support bars extending out of the lower section of the caisson wall; the steel mesh is located between the two formwork units on both sides; a plurality of first tie members and a plurality of second tie members, each of the first tie members being used to tie the bottom of the formwork unit to the steel mesh; each of the second tie members being used to tie the tops of two symmetrically arranged formwork units.

[0006] Based on the above technical means, this support structure makes full use of the existing steel mesh in the caisson structure as tie anchor points, and uses the pre-embedded support bars as the bottom support of the template unit. At the same time, the first tie member and the second tie member are used to constrain the bottom and top of the template unit respectively, forming a stable support system. The structure is simple, the installation is quick, the construction cycle is shortened, and the construction cost is reduced.

[0007] Furthermore, the template unit includes a template and a plurality of timbers, the template being arranged circumferentially on opposite sides of the lower section of the well wall; each of the timbers is installed on the side of the template away from the reinforcing mesh; each of the first tie members is used to connect the bottom end of each of the timbers and the reinforcing mesh; each of the second tie members is used to connect the top of the timbers on opposite sides of the lower section of the well wall.

[0008] Based on the above technical means, timber increases the stress-bearing area of ​​the formwork, so that the tension of the first tie member and the second tie member can be evenly transmitted to the formwork surface, avoiding the first tie member and the second tie member from directly acting on the formwork and causing local damage to the formwork, thus extending the service life of the formwork; at the same time, timber is a common building material, inexpensive, and reusable, resulting in low construction costs.

[0009] Furthermore, each of the first connecting members is an iron wire, which is wound around the steel mesh and the timber and then tied to the timber.

[0010] Based on the above-mentioned technical methods, the material cost of iron wire is low, it is easy to tie, and the construction efficiency is high.

[0011] Furthermore, the wire is a No. 22 wire.

[0012] Based on the above technical means, No. 22 iron wire is a commonly used wire specification on construction sites. It is easy to purchase and inexpensive. The strength of No. 22 iron wire is sufficient to withstand the lateral pressure generated during concrete pouring, and its flexibility makes it easy to tie on site. Under the premise of meeting structural safety, the material cost is minimized.

[0013] Furthermore, the cross-sectional dimensions of each of the aforementioned timbers are 10cm × 10cm.

[0014] Based on the aforementioned technical means, 10cm×10cm is one of the common square timber specifications in the construction industry, with ample market supply, transparent pricing, and low procurement costs.

[0015] Furthermore, the plurality of the timbers are evenly spaced along the length of the template.

[0016] Based on the above technical means, the uniform distribution of timber ensures that the formwork is subjected to uniform stress, avoiding deformation or damage caused by excessive local stress, extending the service life of the formwork, and reducing the cost of formwork maintenance and replacement; at the same time, uniform distribution facilitates standardized construction, improves construction efficiency, and reduces labor costs.

[0017] Furthermore, the spacing between two adjacent timbers is 400mm.

[0018] Furthermore, the second tie member includes a hook-shaped clamp and a movable clamp head. The curved section of the hook-shaped clamp is hooked onto the top of the timber on one side of the steel mesh. The movable clamp head is installed at one end of the hook-shaped clamp away from the curved section and abuts against the timber on the other side of the steel mesh.

[0019] Based on the above technical means, the combination structure of the hook-shaped clamp and the movable clamp head does not require an additional locking structure for installation, making the operation simple and quick; and it eliminates the need to drill holes in the template, avoiding template damage and extending the template's service life.

[0020] Furthermore, the embedded support bar is L-shaped.

[0021] Based on the above technical means, the "L"-shaped pre-embedded support bar structure is simple. The short side of the "L" shape is embedded in the lower section of the well wall, and the long side extends out of the side of the lower section of the well wall to provide support for the template, and the processing cost is low.

[0022] Furthermore, the pre-embedded support ribs are evenly embedded in the lower section of the well wall.

[0023] Based on the above technical means, the uniform distribution of pre-embedded support bars ensures that the formwork is subjected to uniform stress, which is conducive to standardized construction and improves the efficiency of pre-embedded positioning.

[0024] This specification also provides a construction method based on the cast-in-place caisson formwork support structure described in any of the above claims. The formwork unit includes a formwork and multiple timbers, with the formwork arranged circumferentially along the lower section of the caisson wall on opposite sides. Each timber is installed on the side of the formwork away from the reinforcing mesh. The method includes: The first step is to pre-embed the pre-embedded support bars on the inner and outer sides of the top of the lower section of the well wall before pouring the lower section of the well wall. These support bars serve as the bottom support points of the template for the upper caisson wall structure. The pre-embedded support bars are made in an "L" shape, with their short sides anchored into the concrete and their long sides extending horizontally out of the side of the lower section of the well wall. The second step is to tie the steel mesh of the upper caisson wall structure to the top of the lower section of the well wall, and to pre-position the first tie member at the top of the lower section of the well wall using the steel mesh. The third step is to install the template on both the inner and outer sides of the top of the lower section of the well wall, with the short side of the template set vertically and the long side set horizontally; install wooden blocks at 400mm intervals on the side of the template away from the steel mesh, and use the pre-positioned first tie to tie and fix the bottom of the wooden blocks on opposite sides of the lower section of the well wall to the steel mesh so that the wooden blocks support the template; use the second tie to lock the top of the wooden blocks on opposite sides of the lower section of the well wall. The fourth step is to use construction sealant to seal the tiny gaps between the formwork and the lower section of the well wall at the bottom of the formwork to prevent concrete leakage during pouring. The fifth step is to pour the upper caisson wall structure. During pouring, the concrete is poured in layers evenly, with each layer being 30cm to 40cm thick. The upper layer of concrete is poured before the lower layer of concrete has initially set. After each layer of concrete is poured, it is immediately compacted by vibrating with a vibrator.

[0025] The above-mentioned technical solutions adopted in this specification can achieve the following beneficial effects: This support structure makes full use of the existing steel mesh in the caisson structure as tie anchor points, and uses the pre-embedded support bars as the bottom support of the formwork. At the same time, the first tie member and the second tie member are used to constrain the bottom and top of the formwork respectively, forming a stable support system. The structure is simple, the installation is quick, and the construction cost is reduced. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of this specification and form part of this specification, illustrate exemplary embodiments and are used to explain this specification, but do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a top view of the overall structure of the present invention; Figure 2 for Figure 1 Enlarged view of the structure at point A in the middle; Figure 3 This is a cross-sectional view of the overall structure of the present invention; Figure 4 This is a schematic diagram of the structure of the second tie member of the present invention.

[0027] Figure label: 01. Lower section of well wall; 1. Reinforcing mesh; 2. Embedded support bars; 3. Template unit; 31. Template; 32. Timber; 4. First tie member; 5. Second tie member; 51. Hook-shaped clamp; 511. Bending section; 52. Movable clamp head.

[0028] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The same or similar reference numerals correspond to the same or similar components. The terms describing positional relationships in the drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this specification clearer, the technical solutions of this specification will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this specification without creative effort are within the scope of protection of this application.

[0030] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0031] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0032] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0033] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0034] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0035] The technical solutions provided in the various embodiments of this specification are described in detail below with reference to the accompanying drawings.

[0036] This embodiment provides, as follows: Figures 1 to 4 The diagram shows a cast-in-place caisson formwork support structure, including a lower section caisson wall 01, and further comprising: a steel mesh 1 and a plurality of pre-embedded support bars 2 arranged circumferentially along the lower section caisson wall 01, wherein the steel mesh 1 is embedded in the lower section caisson wall 01 and partially extends out of the top surface of the lower section caisson wall 01; each of the pre-embedded support bars 2 is embedded in the lower section caisson wall 01 and partially extends out of the side surface of the lower section caisson wall 01; formwork units 3, which are arranged circumferentially along the lower section caisson wall 01 on opposite sides and supported on the portions of the pre-embedded support bars 2 extending out of the lower section caisson wall 01; the steel mesh 1 is located between the two formwork units 3 on both sides; a plurality of first tie members 4 and a plurality of second tie members 5, wherein each first tie member 4 is used to tie the bottom of the formwork unit 3 to the steel mesh 1; and each second tie member 5 is used to tie the top of two symmetrically arranged formwork units 3.

[0037] This support structure makes full use of the existing steel mesh 1 in the caisson structure as the tie anchor point, and uses the pre-embedded support bar 2 as the bottom support of the template unit 3. At the same time, the first tie member 4 and the second tie member 5 are used to constrain the bottom and top of the template unit 3 respectively, forming a stable support system. The structure is simple, the installation is quick, and the construction cost is reduced.

[0038] like Figure 1 and Figure 2As shown, in this embodiment, the template unit 3 includes a template 31 and multiple timbers 32. The template 31 is arranged circumferentially along the lower section well wall 01 on opposite sides. Each timber 32 is installed on the side of the template 31 away from the reinforcing mesh 1. Each first tie member 4 is used to connect the bottom end of each timber 32 to the reinforcing mesh 1. Each second tie member 5 is used to connect the top of the timbers 32 on opposite sides of the lower section well wall 01. The timbers 32 increase the stress-bearing area of ​​the template 31, so that the tie force of the first tie member 4 and the second tie member 5 is evenly transmitted to the surface of the template 31, avoiding the first tie member 4 and the second tie member 5 from directly acting on the template 31 and causing local damage to the template 31, thus extending the service life of the template 31. At the same time, the timbers 32 are common building materials, low in cost, and reusable, resulting in low construction costs.

[0039] In this embodiment, the template 31 can be made of steel or wood. When pouring the caisson wall, multiple templates 31 are required. Each template 31 is 2440mm × 1220mm in size. Templates 31 are installed on both sides of the caisson wall for pouring.

[0040] In this embodiment, each of the first tie members 4 is made of iron wire. The iron wire is wound around the reinforcing mesh 1 and the timber 32 and then tied to the timber 32. Iron wire is low in material cost, easy to tie, and has high construction efficiency. The reinforcing mesh 1 includes several horizontal reinforcing bars and vertical reinforcing bars. When tying the timber 32 with iron wire, the iron wire can use the horizontal or vertical reinforcing bars as stress points.

[0041] In this embodiment, the wire is a No. 22 wire. Specifically, the diameter of the No. 22 wire is approximately 0.7mm. No. 22 wire is a commonly used wire specification on construction sites, which is easy to purchase and inexpensive; the strength of No. 22 wire is sufficient to withstand the lateral pressure generated during concrete pouring, and its flexibility makes it easy to tie on site, thus minimizing material costs while meeting structural safety requirements.

[0042] like Figure 1 As shown, in this embodiment, the multiple timbers 32 are evenly spaced along the length of the template 31. The even distribution of the timbers 32 ensures uniform stress on the template 31, preventing deformation or damage due to excessive localized stress, extending the template 31's service life, and reducing maintenance and replacement costs. Simultaneously, the even distribution facilitates standardized construction, improves construction efficiency, and reduces labor costs.

[0043] In this embodiment, the spacing between two adjacent timber squares 32 is 400mm. In this embodiment, the preferred cross-sectional size of the timber square 32 is 10cm×10cm, which is one of the common square timber specifications in the construction industry. It is readily available in the market, has transparent pricing, and low procurement costs.

[0044] like Figure 4 As shown, in this embodiment, the second tie member 5 includes a hook-shaped clamp 51 and a movable clamp head 52. The curved section 511 of the hook-shaped clamp 51 hooks onto the top of the wooden block 32 on one side of the reinforcing mesh 1; the movable clamp head 52 is installed at the end of the hook-shaped clamp 51 away from the curved section 511 and abuts against the wooden block 32 on the other side of the reinforcing mesh 1. The combination structure of the hook-shaped clamp 51 and the movable clamp head 52 eliminates the need for an additional locking structure during installation, making the operation simple and quick; it also eliminates the need to drill holes in the template 31, avoiding damage to the template 31 and extending its service life. This structure is commonly used in construction and is known as the "step-by-step tightening" method. It features quick installation and reusability; the specific usage method will not be elaborated here.

[0045] In this embodiment, the pre-embedded support rib 2 is "L" shaped. The "L" shaped pre-embedded support rib 2 has a simple structure. The short side of the "L" shape is completely embedded in the lower section of the well wall 01, while the long side extends out of the side of the lower section of the well wall 01 to provide support for the template 31, and the processing cost is low.

[0046] In this embodiment, the pre-embedded support bars 2 are evenly spaced and embedded in the lower section of the well wall 01. The even distribution of the pre-embedded support bars 2 ensures uniform stress on the template 31, which is beneficial for standardized construction and improves the efficiency of pre-embedded positioning. The pre-embedded support bars 2 have a diameter of 16mm and a spacing of 600mm.

[0047] The caisson template 31 support structure in this embodiment can be used for both circular and square cross-section caissons. When used for a circular cross-section caisson, the timber slabs 32 on the outer side of the caisson wall are evenly spaced along the outer side of the circular caisson wall, with a distance of 400mm between adjacent timber slabs 32 (along the circumference of the circle). The timber slabs 32 on the inner side of the caisson wall are positioned on the straight line corresponding to the timber slabs 32 on the outer side of the caisson wall, along the diameter of the circular caisson wall. When used for a square cross-section caisson, the spacing of the timber slabs 32 in the straight line is 400mm (the spacing of the timber slabs 32 on both the inner and outer sides of the caisson wall is 400mm). At the corners of the square caisson, the spacing of the timber slabs 32 is set according to actual construction requirements.

[0048] In summary, when using the caisson template 31 support structure in this embodiment to pour the caisson wall above the lower section caisson wall 01, the following construction methods and steps shall be followed: The first step is to pre-embed 16mm diameter and 600mm spacing support bars 2 on the top inner and outer sides of the lower section well wall 01 before pouring the lower section well wall 01. These support bars serve as the bottom support points of the upper caisson well wall structure template 31. The pre-embedded support bars 2 are made into an "L" shape, with the short side anchored into the concrete and the long side extending horizontally outward from the outside of the lower section well wall 01.

[0049] The second step involves constructing the upper caisson wall structure when the lower section of the well wall 01 has sunk to a height of more than 50cm above the ground. (An appropriate height for the segmented joints of the well wall structure should be selected to reduce lateral pressure during concrete pouring.) A segmented joint height of 1.2m (the height of each section of the well wall) is preferred. After the reinforcing mesh 1 of the upper caisson wall structure is tied, the vertical or horizontal reinforcing bars of the reinforcing mesh 1 are pre-tied with #22 wire at 400mm intervals on both the inner and outer sides of the top of the lower section of the well wall 01 (the reinforcing mesh 1 should have at least two rows of horizontal reinforcing bars and two rows of vertical reinforcing bars). Wires extending from the outer side of the lower section of the well wall 01 are used to tie the horizontal or vertical reinforcing bars of the reinforcing mesh 1 closer to the center of the caisson. Wires extending from the inner side of the lower section of the well wall 01 are used to tie the horizontal or vertical reinforcing bars of the reinforcing mesh 1 away from the center of the caisson. (The inner side refers to the side of the lower section of the well wall 01 closest to the center of the caisson, and the outer side refers to the side of the lower section of the well wall 01 away from the center of the caisson.) The third step is to install the template 31, which can be either steel or wood. Taking the wood template 31 as an example, a 2440mm×1220mm wood template 31 is used. Templates 31 are installed on both the inner and outer sides of the lower section well wall 01. The short side of the template 31 is set vertically and the long side is set horizontally. On the side of the template 31 away from the steel mesh 1, timber 32 is installed at 400mm intervals. The cross-sectional size of the timber 32 is 10cm×10cm. The bottom of the timber 32 on both sides of the lower section well wall 01 is tied and fixed with the 22# iron wire pre-set in the second step. The top of the template 31 is locked with the top of the timber 32 on both sides of the well wall using the second tie piece 5 (step-by-step tightening) (hook the bent section 511 of the hook-shaped clamp 51 to the top of the timber 32 on one side of the lower section well wall 01, adjust the movable clamp head 52 to hold the top of the timber 32 on the other side of the lower section well wall 01 and lock it, thus completing the tie and fixation of the top of the template 31). When pouring concrete for a square cross-section well wall, threaded steel bars with a diameter of 20mm or more can be used instead of 32mm timber at the external corners of the well wall. These steel bars have high strength and are not easily damaged.

[0050] The fourth step is to use sealant to seal the tiny gap between the template 31 and the lower section of the well wall 01 at the bottom of the template 31 to prevent grout leakage during concrete pouring.

[0051] The fifth step is to use a concrete pump to pour the upper caisson wall structure (i.e., the structure above the lower section 01 of the caisson wall). The concrete is poured in layers evenly. The upper layer of concrete is poured before the lower layer of concrete has initially set. The layer thickness is ≤50cm, and the layer thickness is preferably 30-40cm. After pouring each layer of concrete, the concrete is immediately compacted by vibrating with a vibrator. During vibration, the vibrator needs to be inserted at least 10cm into the lower layer of concrete to facilitate effective bonding between the layers and avoid construction cold joints in the structure.

[0052] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A cast-in-place caisson formwork support structure, comprising a lower section of the caisson wall (01), characterized in that, Also includes: A steel mesh (1) and a plurality of pre-embedded support bars (2) arranged circumferentially along the lower section well wall (01), wherein the steel mesh (1) is embedded in the lower section well wall (01) and partially extends out of the top surface of the lower section well wall (01); each of the pre-embedded support bars (2) is embedded in the lower section well wall (01) and partially extends out of the side surface of the lower section well wall (01); Template unit (3), the template unit (3) is arranged on opposite sides of the lower section well wall (01) in the circumferential direction and is erected on the part of the multiple pre-embedded support bars (2) extending out of the lower section well wall (01); the steel mesh (1) is located between the template units (3) on both sides; Multiple first tie members (4) and multiple second tie members (5), each of the first tie members (4) is used to tie the bottom of the template unit (3) to the steel mesh (1); each of the second tie members (5) is used to tie the top of two symmetrically arranged template units (3).

2. The cast-in-place caisson formwork support structure according to claim 1, characterized in that, The template unit (3) includes a template (31) and a plurality of timbers (32). The template (31) is arranged along the circumference of the lower section well wall (01) on opposite sides. Each timber (32) is installed on the side of the template (31) away from the steel mesh (1). Each first tie member (4) is used to connect the bottom end of each timber (32) and the steel mesh (1). Each second tie member (5) is used to connect the top of the timbers (32) on opposite sides of the lower section well wall (01).

3. The cast-in-place caisson formwork support structure according to claim 2, characterized in that, Each of the first tie members (4) is an iron wire, which is wrapped around the steel mesh (1) and the wooden block (32) and then tied to the wooden block (32).

4. The cast-in-place caisson formwork support structure according to claim 3, characterized in that, The wire in question is a No. 22 wire.

5. A cast-in-place caisson formwork support structure according to claim 2, characterized in that, Multiple timbers (32) are evenly spaced along the length of the template (31).

6. The cast-in-place caisson formwork support structure according to claim 5, characterized in that, The spacing between two adjacent timbers (32) is 400mm.

7. The cast-in-place caisson formwork support structure according to claim 2, characterized in that, The second tie member (5) includes a hook-shaped clamp (51) and a movable clamp (52). The curved section (511) of the hook-shaped clamp (51) is hooked to the top of the wooden block (32) on one side of the steel mesh (1). The movable clamp (52) is installed at one end of the hook-shaped clamp (51) away from the curved section (511) and abuts against the wooden block (32) on the other side of the steel mesh (1).

8. The cast-in-place caisson formwork support structure according to claim 1, characterized in that, The pre-embedded support bar (2) is "L" shaped.

9. A cast-in-place caisson formwork support structure according to claim 1 or 8, characterized in that, The pre-embedded support bars (2) are evenly embedded in the lower section of the well wall (01).

10. A construction method, based on the cast-in-place caisson formwork support structure according to any one of claims 1 to 9, characterized in that, The template unit (3) includes a template (31) and multiple wooden blocks (32), with the template (31) arranged on opposite sides of the lower section well wall (01) along its circumference; Each of the aforementioned timbers (32) is installed on the side of the template (31) away from the reinforcing mesh (1); The method includes: First, before pouring the lower section well wall (01), the pre-embedded support bars (2) are pre-embedded on the inner and outer sides of the top of the lower section well wall (01) as the bottom support points of the template (31) of the upper caisson well wall structure; the pre-embedded support bars (2) are made into an "L" shape, with their short side anchored into the concrete and their long side extending horizontally out of the side of the lower section well wall (01). The second step is to tie the steel mesh (1) of the upper caisson wall structure to the top of the lower section well wall (01), and to pre-position the first tie member (4) using the steel mesh (1) at the top of the lower section well wall (01). The third step is to install the template (31) on both the inner and outer sides of the top of the lower section well wall (01). The short side of the template (31) is set vertically and the long side is set horizontally. Wooden blocks (32) are installed at intervals of 400mm on the side of the template (31) away from the steel mesh (1). The bottom of the wooden blocks (32) on the opposite sides of the lower section well wall (01) is tied and fixed to the steel mesh (1) with the first tie member (4) that is pre-positioned, so that the wooden blocks (32) abut against the template (31). The top of the wooden blocks (32) on the opposite sides of the lower section well wall (01) is locked with the second tie member (5). The fourth step is to use construction sealant to seal the tiny gap between the template (31) and the lower section of the well wall (01) at the bottom of the template (31) to prevent concrete leakage during pouring; The fifth step is to pour the upper caisson wall structure. During pouring, the concrete is poured in layers evenly, with each layer being 30cm to 40cm thick. The upper layer of concrete is poured before the lower layer of concrete has initially set. After each layer of concrete is poured, it is immediately compacted by vibrating with a vibrator.

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