Rectangular assembly type open caisson prefabricated well piece assembling method

Abstract

The invention discloses an assembling method for prefabricated well pieces of a rectangular assembly type open caisson. The rectangular assembly type open caisson comprises a plurality of annular well sections which are sequentially connected end to end in the length direction. Each circumferential well section comprises more than two prefabricated well pieces to form four splicing structures; the splicing process comprises the following steps that firstly, all the prefabricated well pieces are spliced into corresponding circumferential well sections; 2, blade foot ring well sections are assembled; and 3, the blade foot ring well sections are sunk, all the circumferential well sections are spliced on the blade foot ring well sections one by one, and sinking at the corresponding height is carried out after splicing of one circumferential well section is completed till sinking of all the circumferential well sections of the rectangular assembly type open caisson is completed. By means of the method, the rectangular assembly type open caisson can be flexibly disassembled, well piece lightweight transportation, positioning, reliable connection and efficient splicing are achieved, and the structural integrity and the construction quality of the open caisson are improved.

Description

Technical Field

[0001] This invention relates to the field of rectangular prefabricated caisson technology, and particularly to a method for assembling prefabricated caisson segments. Background Technology

[0002] In the field of underground engineering, caissons are often constructed using either cast-in-place reinforced concrete caissons or precast monolithic caissons. Cast-in-place caissons require a steel reinforcement processing area on-site for steel reinforcement binding, formwork erection, and casting of the caisson body. This requires a large site area, a large number of construction workers, and the use of tall formwork support systems. The construction safety risks associated with scaffolding erection and high-altitude operations are relatively high, the construction period is long, and the overall economic cost is high. Precast monolithic caissons, on the other hand, are designed with monolithic caisson segments. Each segment is heavy, resulting in high transportation and hoisting difficulties and costs.

[0003] Therefore, how to reduce the weight of rectangular prefabricated caissons while improving their stability and construction efficiency to overcome the shortcomings of existing technologies has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of the above-mentioned defects of the prior art, the present invention provides a method for assembling prefabricated well segments of rectangular assembled caissons. The purpose is to reduce the weight of rectangular assembled caissons while improving their stability and construction efficiency, thereby solving the defects of the prior art.

[0005] To achieve the above objectives, this invention discloses a method for assembling prefabricated sections of a rectangular prefabricated caisson, wherein the rectangular prefabricated caisson comprises multiple circumferential sections that are connected end to end along the length direction.

[0006] Each of the aforementioned circumferential well sections comprises two or more prefabricated well segments, forming the following four splicing structures:

[0007] All the prefabricated well segments of the first type of splicing structure include only two U-shaped well segments, both of which have a U-shaped cross-section in the rectangular assembled caisson;

[0008] All the prefabricated well segments of the second type of splicing structure include two U-shaped well segments and a straight well segment disposed between the two U-shaped well segments, the cross-section of which is straight.

[0009] The third type of splicing structure includes only four L-shaped well pieces, all of which have an L-shaped cross-section in the rectangular assembled caisson.

[0010] The fourth type of splicing structure includes four L-shaped well segments and a straight well segment disposed between every two adjacent L-shaped well segments.

[0011] The assembly process includes the following steps:

[0012] Step 1: Assemble all the prefabricated well segments into the corresponding circumferential well sections;

[0013] Step 2: Assemble the cutting edge ring well section;

[0014] Step 3: Lower the cutting edge ring section, and then assemble all the circumferential well sections one by one on the cutting edge ring section. After assembling one circumferential well section, proceed to the corresponding height of lowering until all the circumferential well sections of the rectangular prefabricated caisson are lowered.

[0015] Preferably, the circumferential joint formed by any two prefabricated well segments in each circumferential well section is aligned with or staggered from the circumferential joint formed by the corresponding two prefabricated well segments in the adjacent circumferential well section.

[0016] More preferably, each of the two prefabricated well segments in each circumferential well section is provided with a matching joint tenon and joint groove at the jointing position, which are connected by the corresponding joint groove and joint tenon. In addition, a bolt hole is reserved at the joint end face of the two prefabricated well segments in each circumferential splice. When the prefabricated well segments are connected, the bolt passes through the corresponding reserved hand hole and is tightened by a nut.

[0017] Preferably, among all the circumferential well sections, the circumferential well section located at the lowest end of the rectangular prefabricated caisson is the cutting-edge circumferential well section.

[0018] Preferably, step 1 is as follows:

[0019] For the first type of splicing structure, two U-shaped well segments with the same structure are symmetrically spliced ​​together to form the corresponding rectangular well section;

[0020] For the third type of splicing structure, four L-shaped well segments with the same structure are symmetrically spliced ​​together to form the corresponding rectangular well section;

[0021] For the second type of splicing structure, two U-shaped well plates are used to form two opposite sides of the corresponding rectangular well section, and then the straight well plate is inserted between the two U-shaped well plates to form the remaining two sides, splicing them together to form the corresponding rectangular well section;

[0022] For the fourth type of splicing structure, four L-shaped well plates are used to form the four corners of the corresponding rectangular well section, and then the straight well plate is inserted between the four L-shaped well plates to form the four sides of the corresponding rectangular well section, and spliced ​​together to form the corresponding rectangular well section.

[0023] More preferably, in step 3,

[0024] Each pair of adjacent circumferential well sections is aligned by an annular groove around the mating surfaces of the two circumferential well sections, and is fixed by providing multiple steel plates, each welded to the two circumferential well sections, on the inner and / or outer sides.

[0025] More preferably, each of the joint tenons fits tightly with the corresponding joint groove, and a double waterproofing structure is formed by embedding a water-swellable rubber strip and a sealing gasket in a pre-reserved annular waterproof groove.

[0026] More preferably, each of the joint tenons and the corresponding joint grooves are concave-convex or Z-shaped, and bolts are provided for fastening at the positions corresponding to the inner and / or outer sides of the rectangular assembled caisson.

[0027] More preferably, each of the welded circumferential well sections uses inter-ring fixing bolts screwed into the threaded holes on the surface of the well plate to achieve a fixed connection between the two circumferential well sections.

[0028] Each of the aforementioned circumferential well sections has a corresponding pre-embedded threaded pipe on the inter-ring fixing bolts of the welded steel plate of each welded circumferential well section.

[0029] After each nut is tightened, the bolt preload is checked to ensure that the design requirements are met.

[0030] Preferably, step 3 is as follows:

[0031] Step 3.1: At the predetermined location of the caisson on the ground, assemble the cutting edge ring section in a circumferential manner, or splice the cutting edge ring section with the first circumferential section above it into a whole, and then use the caisson process to carry out the first sinking.

[0032] Step 3.2: Vertically connect the remaining circumferential well section with the cutting edge circumferential well section, and continue to sink it using the caisson process until it reaches the predetermined elevation, thus completing the assembly and positioning of the rectangular prefabricated caisson body.

[0033] The beneficial effects of this invention are:

[0034] The application of this invention enables the flexible disassembly of rectangular prefabricated caissons, achieving lightweight transportation, positioning, reliable connection, and efficient assembly of caisson segments, thereby improving the overall integrity of the caisson structure and the quality of construction.

[0035] This invention optimizes the classification design of prefabricated well segments, clarifies the functional positioning of straight, L-shaped, and U-shaped (including equilateral and unequal-sided) segments, realizes lightweight and standardized production of well segments, reduces the weight of a single well segment, facilitates transportation and hoisting, reduces reliance on large hoisting equipment, reduces construction costs and risks, and at the same time improves the versatility and interchangeability of well segments.

[0036] This invention clarifies four core assembly logics, forming a differentiated assembly method that can flexibly adapt to different working conditions: it is suitable for staggered rectangular prefabricated caissons, has high assembly efficiency, can adapt to rectangular prefabricated caissons of various sizes, and the caisson panels can be disassembled and hoisted, reducing the site hoisting capacity requirements and fully covering the needs of different engineering scenarios.

[0037] This invention addresses the issue of numerous joints by refining the design of the water-stopping, fastening, and connection structures. It employs a double water-stopping structure, a double fastening method, and reinforced connection measures, which simplifies the connection process, improves assembly efficiency, ensures connection strength and joint sealing, effectively controls the verticality, horizontality, and dimensional deviations of the caisson, and enhances the integrity and stability of the caisson structure.

[0038] The construction process of this invention is clear and orderly, and the prefabrication and assembly of various well segments can be carried out in parallel. Compared with traditional cast-in-place caissons, it significantly shortens the construction period, reduces on-site work, and reduces the impact on the surrounding environment and traffic. At the same time, the assembly quality is easy to control and the later maintenance is convenient, which has good engineering application value.

[0039] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0040] Figure 1 The diagram shows an exploded structural diagram of two equilateral U-shaped well sections joined together to form a circumferential well section in one embodiment of the present invention.

[0041] Figure 2 This diagram illustrates a structural schematic of two equilateral U-shaped well sections joined together to form a circumferential well section, according to one embodiment of the present invention.

[0042] Figure 3 The diagram shows an exploded structural diagram of two unequal-sided U-shaped well sections connected to form a circumferential well section in one embodiment of the present invention.

[0043] Figure 4 This diagram illustrates a structure in one embodiment of the present invention where two unequal-sided U-shaped well sections are joined together to form a circumferential well section.

[0044] Figure 5 This diagram shows an exploded view of a fourth type of splicing structure in one embodiment of the present invention, where bolts are used for fastening only on the inner side of a rectangular prefabricated caisson.

[0045] Figure 6 This diagram illustrates a fourth type of splicing structure in one embodiment of the present invention, where bolts are used for fastening only on the inner side of a rectangular prefabricated caisson.

[0046] Figure 7This diagram shows an exploded view of a fourth type of splicing structure in an embodiment of the present invention, in which bolts are installed on both the inner and outer sides of a rectangular prefabricated caisson.

[0047] Figure 8 This diagram illustrates a fourth type of splicing structure in an embodiment of the present invention, in which bolts are installed on both the inner and outer sides of a rectangular prefabricated caisson for fastening.

[0048] Figure 9 This diagram shows an exploded view of a second splicing structure in one embodiment of the present invention, where bolts are used for fastening only on the inner side of a rectangular prefabricated caisson.

[0049] Figure 10 This diagram illustrates a second splicing structure in one embodiment of the present invention, where bolts are used for fastening only on the inner side of a rectangular prefabricated caisson.

[0050] Figure 11 This diagram shows an exploded view of a second splicing structure in an embodiment of the present invention, in which bolts are installed on both the inner and outer sides of a rectangular prefabricated caisson for fastening.

[0051] Figure 12 This diagram illustrates a second type of splicing structure in an embodiment of the present invention, in which bolts are installed on both the inner and outer sides of a rectangular prefabricated caisson for fastening.

[0052] Figure 13 The diagram shows a side view of the first or third splicing structure in one embodiment of the present invention.

[0053] Figure 14 The diagram shows a side view of the second or fourth splicing structure in one embodiment of the present invention.

[0054] Figure 15 This diagram illustrates the structural connection between two circumferential well sections in one embodiment of the present invention. Detailed Implementation

[0055] Example 1: As Figures 1 to 14 As shown, the method for assembling prefabricated well segments of a rectangular prefabricated caisson includes multiple circumferential well sections that are connected end to end along the length direction.

[0056] Each annular well section consists of two or more prefabricated well segments, forming the following four splicing structures:

[0057] The first type of splicing structure consists of only two U-shaped well segments, both of which have a U-shaped cross-section in the rectangular assembled caisson.

[0058] The second type of splicing structure includes two U-shaped well segments and a straight well segment set between the two U-shaped well segments, which has a straight cross-section in the rectangular assembled caisson.

[0059] The third type of splicing structure consists of only four L-shaped well segments, each with an L-shaped cross-section in the rectangular assembled caisson.

[0060] The fourth type of splicing structure consists of four L-shaped well segments and a straight well segment set between every two adjacent L-shaped well segments.

[0061] In practical applications, the prefabricated well plates of the present invention include three types: straight well plates, L-shaped well plates, and U-shaped well plates. Among them, the straight well plate is a rectangular flat plate structure used to form the well wall on the side of the rectangular prefabricated caisson; the L-shaped well plate is a 90° angled structure with chamfered corners, used to form the corner parts of the rectangular prefabricated caisson; the U-shaped well plate is a "U" shaped structure, which can be divided into equilateral U-shaped well plates and unequal-sided U-shaped well plates.

[0062] The assembly process includes the following steps:

[0063] Step 1: Assemble all prefabricated well segments into corresponding circumferential well sections;

[0064] Step 2: Assemble the cutting edge ring well section;

[0065] Step 3: Lower the cutting edge ring section, and then assemble all the circumferential well sections one by one on the cutting edge ring section. After assembling one circumferential well section, proceed to the corresponding height of lowering until all the circumferential well sections of the rectangular prefabricated caisson are lowered.

[0066] This invention employs prefabricated well segments connected into a ring, and then assembled vertically into a caisson. The prefabricated well segments are manufactured in a factory, and on-site, they are connected and assembled into a ring using tie-and-joint methods. The caisson is then lowered into place using a caisson process, improving construction efficiency and shortening the on-site construction period. This method is suitable for underground engineering scenarios requiring prefabrication and assembly processes and where there are strict limitations on the volume of individual prefabricated components. Such scenarios often involve narrow construction sites, restricted transportation routes, inability to access large hoisting equipment, or limited on-site construction space preventing large-scale cast-in-place construction, necessitating the use of prefabrication and assembly. Furthermore, these projects have stringent requirements on the volume of individual prefabricated well segments, necessitating weight reduction through segment division. This facilitates transport by conventional vehicles, reduces the difficulty of short-distance handling, and allows for more precise placement in confined spaces without relying on large hoisting equipment, significantly reducing construction costs and safety risks. This method is particularly suitable for caisson construction in urban core areas and around existing buildings where construction space is limited.

[0067] In some embodiments, the circumferential joint formed by any two prefabricated well segments in each circumferential well section is aligned with or staggered from the circumferential joint formed by the corresponding two prefabricated well segments in another adjacent circumferential well section.

[0068] In practical applications, when there are only two U-shaped well sections, the U-shaped well sections of the circumferential well sections with aligned circumferential splice seams have the same length on both sides and are equilateral, while the U-shaped well sections of the circumferential well sections with staggered circumferential splice seams have different lengths on both sides and are unequal.

[0069] In some embodiments, at the joint position of any two precast well segments in each circumferential well section, there are matching joint tenons and joint grooves, which are connected by the corresponding joint grooves and tenons. In addition, at the joint end face of the two precast well segments of each circumferential splice, there are pre-reserved hand holes for bolt connection. When the corresponding precast well segments are connected, the bolts pass through the corresponding pre-reserved hand holes and are tightened by nuts.

[0070] In practical applications, high-strength bolts are used.

[0071] In some embodiments, among all the circumferential well sections, the circumferential well section located at the bottom of the rectangular prefabricated caisson is a cutting-edge circumferential well section.

[0072] In some embodiments, step 1 is specifically as follows:

[0073] For the first type of splicing structure, two U-shaped well segments with the same structure are symmetrically spliced ​​together to form a corresponding rectangular well section;

[0074] For the third type of splicing structure, four identical L-shaped well segments are symmetrically spliced ​​together to form a corresponding rectangular well section.

[0075] For the second type of splicing structure, two U-shaped well plates are used to form two opposite sides of the corresponding rectangular well section, and then a straight well plate is inserted between the two U-shaped well plates to form the remaining two sides, which are then spliced ​​together to form the corresponding rectangular well section.

[0076] For the fourth splicing structure, four L-shaped well plates are used to form the four corners of the corresponding rectangular well section. Then, a straight well plate is inserted between the four L-shaped well plates to form the four sides of the corresponding rectangular well section, and splicing them together to form the corresponding rectangular well section.

[0077] In practical applications, the above assembly method is used to assemble prefabricated well segments into cutting edge ring well sections and standard ring well sections (all circumferential well sections except the cutting edge ring well section are standard ring well sections). A complete rectangular prefabricated caisson is assembled from bottom to top by one rectangular cutting edge ring well section and n standard ring well sections.

[0078] The staggered circumferential splicing seams of every two adjacent circumferential well sections can further improve the overall stability of the caisson.

[0079] like Figure 15 As shown, in some embodiments, in step 3,

[0080] Each pair of adjacent circumferential well sections is aligned by an annular groove tenon surrounding the mating surfaces of the two circumferential well sections, and is fixed by providing multiple steel plates, each welded to the two circumferential well sections, on the inner and / or outer sides.

[0081] In some embodiments, the welded steel plate of the circumferential well section has each joint tenon tightly fitted with the corresponding joint groove, and a double water-stop structure is formed by embedding a water-swellable rubber strip and a sealing gasket in a pre-reserved annular water-stop groove.

[0082] In practical applications, the tight fit between the tenon and the corresponding groove of each joint surface can extend the seepage path of external groundwater into the well. The water-swellable rubber strip precisely matches the groove to ensure a tight fit. At the same time, a sealing gasket can be added to the water-stop groove to form a double water-stop structure of "tenon groove water-stop + water-swellable water-stop", which effectively prevents water seepage inside and outside the well and is suitable for engineering scenarios with abundant groundwater and high waterproof requirements.

[0083] In some embodiments, each joint tenon and the corresponding joint groove are concave-convex or Z-shaped, and bolts are provided for fastening at the inner and / or outer sides of the corresponding rectangular prefabricated caisson.

[0084] In practical applications, each joint tenon and corresponding joint groove are concave-convex or Z-shaped to ensure that the joints of the precast well segments are tightly fitted. In addition to the inner bolts, reinforcement bolts can be added to the outer side of the joints of adjacent precast well segments. That is, the circumferential connection of the well segments is fastened with two sets of bolts, one inner and one outer, evenly arranged vertically along the joint. The spacing is set according to the size of the well segments and the stress requirements to further enhance the tightness of the joint.

[0085] In some embodiments, each of the welded circumferential well sections is fitted with an inter-ring fixing bolt screwed into a threaded hole on the surface of the well plate to achieve a fixed connection between the two circumferential well sections.

[0086] Each of the aforementioned circumferential well sections has a corresponding pre-embedded threaded pipe on the inter-ring fixing bolts of the welded steel plate of each welded circumferential well section.

[0087] After each nut is tightened, the bolt preload is checked to ensure that the design requirements are met. Circumferential well section welded steel plate.

[0088] In practical applications, all the reserved threaded holes in the welded steel plates of each welded ring section are aligned along the length of the rectangular assembled caisson to ensure that high-strength bolts can pass vertically through the upper and lower sections.

[0089] In some embodiments, step 3 is specifically as follows:

[0090] Step 3.1: At the predetermined location of the caisson on the ground, assemble the cutting edge ring section in a circumferential manner, or splice the cutting edge ring section with the first circumferential section above it into a whole, and then use the caisson process to carry out the first sinking.

[0091] Step 3.2: Vertically connect the remaining circumferential well section with the cutting edge circumferential well section, and continue to sink it using the caisson process until it reaches the predetermined elevation, thus completing the assembly and positioning of the rectangular prefabricated caisson body.

[0092] In practical applications, during the initial sinking, only the cutting edge ring section can be sunk, or the rectangular cutting edge ring section and the first standard ring section can be vertically connected at the predetermined caisson position to form a whole before the initial sinking is carried out using the caisson process.

[0093] Example 2: Figures 1 to 4 As shown, two equilateral / unequal-sided U-shaped well segments are assembled into a circumferential well section. The specific steps are as follows:

[0094] ① Lift the first equilateral / unequal-sided U-shaped well piece, align it with the positioning line, and temporarily fix it;

[0095] ②The second equilateral / unequal-sided U-shaped well plate is lifted symmetrically, with the openings aligned and the bolt holes precisely aligned;

[0096] ③ Insert high-strength bolts, tighten nuts, and compact the water-swellable rubber strip;

[0097] ④ Check that the overall dimensional deviation meets the requirements and complete the well section assembly.

[0098] Example 3: As Figures 5 to 8 As shown, the assembly process for the fourth type of splicing structure is as follows:

[0099] ① Lift four L-shaped well segments in sequence, position them at the four corners, adjust their verticality and horizontality, and then fix them with temporary tie rods to form a rectangular corner frame;

[0100] ② Insert n straight-line well plates to fill the gap between the long and short sides, and ensure that the bolt connection holes are aligned;

[0101] ③ Remove the temporary tie rod, insert the high-strength bolt, tighten the nut, and compact the water-swellable rubber strip;

[0102] ④ Check that the overall dimensional deviations meet the requirements and complete the well section assembly.

[0103] Example 4: Figures 9 to 12 As shown, the assembly process for the second type of splicing structure is as follows:

[0104] ① Lift two equilateral / unequal-sided U-shaped well segments in sequence, position them at both ends of the caisson, adjust their verticality and horizontality, and then fix them with temporary tie rods to form a rectangular frame;

[0105] ② Insert n straight-line well plates to fill the gap between the long and short sides, and ensure that the bolt connection holes are aligned;

[0106] ③ Remove the temporary tie rod, insert the high-strength bolt, tighten the nut, and compact the water-swellable rubber strip;

[0107] ④ Check that the overall dimensional deviation meets the requirements and complete the well section assembly.

[0108] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for assembling prefabricated well segments of a rectangular prefabricated caisson; characterized in that, A rectangular prefabricated caisson consists of multiple circumferential caisson sections connected end to end along its length. Each of the aforementioned circumferential well sections comprises two or more prefabricated well segments, forming the following four splicing structures: All the prefabricated well segments of the first type of splicing structure include only two U-shaped well segments, both of which have a U-shaped cross-section in the rectangular assembled caisson; All the prefabricated well segments of the second type of splicing structure include two U-shaped well segments and a straight well segment disposed between the two U-shaped well segments, the cross-section of which is straight. The third type of splicing structure includes only four L-shaped well pieces, all of which have an L-shaped cross-section in the rectangular assembled caisson. The fourth type of splicing structure includes four L-shaped well segments and a straight well segment disposed between every two adjacent L-shaped well segments. The assembly process includes the following steps: Step 1: Assemble all the prefabricated well segments into the corresponding circumferential well sections; Step 2: Assemble the cutting edge ring well section; Step 3: Lower the cutting edge ring section, and then assemble all the circumferential well sections one by one on the cutting edge ring section. After assembling one circumferential well section, proceed to the corresponding height of lowering until all the circumferential well sections of the rectangular prefabricated caisson are lowered.

2. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 1, characterized in that, In each circumferential well section, the circumferential joint formed by the connection of any two prefabricated well segments is aligned with or staggered from the circumferential joint formed by the connection of the corresponding two prefabricated well segments in the adjacent circumferential well section.

3. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 2, characterized in that, In each of the circumferential well sections, the joint positions of any two prefabricated well segments are respectively provided with matching joint tenons and joint grooves, which are connected by the corresponding joint grooves and joint tenons. In addition, at the joint end faces of the two prefabricated well segments in each circumferential splice, there are pre-reserved hand holes for bolt connection. When the prefabricated well segments are connected, the bolts pass through the corresponding pre-reserved hand holes and are tightened by nuts.

4. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 1, characterized in that, Of all the circumferential well sections, the circumferential well section located at the lowest end of the rectangular prefabricated caisson is the cutting-edge circumferential well section.

5. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 1, characterized in that, Step 1 is as follows: For the first type of splicing structure, two U-shaped well segments with the same structure are symmetrically spliced ​​together to form the corresponding rectangular well section; For the third type of splicing structure, four L-shaped well segments with the same structure are symmetrically spliced ​​together to form the corresponding rectangular well section; For the second type of splicing structure, two U-shaped well plates are used to form two opposite sides of the corresponding rectangular well section, and then the straight well plate is inserted between the two U-shaped well plates to form the remaining two sides, splicing them together to form the corresponding rectangular well section; For the fourth type of splicing structure, four L-shaped well plates are used to form the four corners of the corresponding rectangular well section, and then the straight well plate is inserted between the four L-shaped well plates to form the four sides of the corresponding rectangular well section, and spliced ​​together to form the corresponding rectangular well section.

6. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 5, characterized in that, In step 3, Each pair of adjacent circumferential well sections is aligned by an annular groove around the mating surfaces of the two circumferential well sections, and is fixed by providing multiple steel plates, each welded to the two circumferential well sections, on the inner and / or outer sides.

7. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 6, characterized in that, Each of the joint tenons fits tightly with the corresponding joint groove, and a double waterproof structure is formed by embedding a water-swellable rubber strip and a sealing gasket in a pre-reserved annular waterproof groove.

8. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 6, characterized in that, Each of the joint tenons and the corresponding joint grooves are concave-convex or Z-shaped, and bolts are provided for fastening at the inner and / or outer positions of the corresponding rectangular assembled caisson.

9. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 6, characterized in that, Each of the aforementioned annular well section welded steel plates is fixed to the corresponding two annular well sections by inter-annular fixing bolts; Each of the aforementioned annular well joints is provided with a pre-embedded threaded pipe corresponding to each of the aforementioned inter-annular fixing bolts; After each nut is tightened, the bolt preload is checked to ensure that the design requirements are met.

10. The method for assembling prefabricated well segments of a rectangular prefabricated caisson according to claim 1, characterized in that, Step 3 is as follows: Step 3.1: At the predetermined location of the caisson on the ground, assemble the cutting edge ring section in a circumferential manner, or splice the cutting edge ring section with the first circumferential section above it into a whole, and then use the caisson process to carry out the first sinking. Step 3.2: Vertically connect the remaining circumferential well section with the cutting edge circumferential well section, and continue to sink it using the caisson process until it reaches the predetermined elevation, thus completing the assembly and positioning of the rectangular prefabricated caisson body.

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