Back-to-back assembly type module and construction method

Abstract

The application discloses a back-to-back assembled module and a construction method, relates to the technical field of assembled structures, and comprises a box body, the box body comprises a top plate and a back plate arranged in a circumferential direction at the bottom of the top plate, an annular lap joint rib for connecting adjacent box bodies is arranged on the back plate, the annular lap joint rib is arranged vertically, the annular lap joint ribs on the back plates of adjacent box bodies are in contact, and a first post-poured groove for pouring is formed between the back plates of adjacent box bodies. The annular lap joint rib is arranged vertically on the back plate, interference of the annular lap joint rib between adjacent box bodies can be effectively avoided when the box body is hoisted, smooth vertical hoisting and positioning of the box body are achieved, complicated transverse adjustment is not needed, the integrity and stress performance of the connection of the box body are enhanced through the annular lap joint rib, the unity of construction convenience and structural reliability is achieved, the connection precision between the back-to-back box bodies can be achieved without binding, and the connection efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of prefabricated structure technology, specifically to a back-to-back prefabricated module and its construction method. Background Technology

[0002] With the deepening of industrialized construction and the "dual-carbon" goals, modular buildings, due to their advantages such as high prefabrication, high proportion of on-site dry work, and short construction cycle, are becoming an important direction for the development of prefabricated buildings. Back-to-back modular systems, by symmetrically splicing two independent three-dimensional spatial units along side panels, can efficiently form standard rooms or structural units, and are widely used in residential, hotel, and emergency construction fields. However, this system still faces key challenges in practical applications: how to achieve reliable, efficient, and industrially compatible horizontal and vertical collaborative connections between modules to ensure that the overall structure has good load-bearing capacity, stiffness continuity, and seismic performance.

[0003] In existing technologies, the connection between modules mostly relies on methods such as post-cast concrete strips, sleeve grouting, or welding of pre-embedded steel plates. Between back-to-back modules, the operating space is extremely narrow, making it almost impossible for workers to perform high-quality rebar tying and concrete vibration, easily leading to voids and honeycombing. Furthermore, when hoisting back-to-back modules, not only is vertical hoisting required, but horizontal adjustment is also necessary due to the obstruction of pre-embedded parts, reducing assembly efficiency.

[0004] Therefore, it is necessary to develop and design back-to-back prefabricated modules and construction methods that can achieve high connection accuracy between back-to-back modules without binding, and improve connection efficiency. These are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a back-to-back assembled module and construction method that achieves precise connection between back-to-back modules without the need for binding, thereby improving connection efficiency.

[0006] To achieve the above objectives, the present invention provides the following solution: A back-to-back assembled module includes a box body, the box body including a top plate and a back plate disposed on the bottom circumferential direction of the top plate, the back plate being provided with annular lap joints for connecting adjacent boxes, the annular lap joints being arranged vertically, and the annular lap joints on the back plates of adjacent boxes having horizontal projections that overlap, and a first post-casting groove for pouring is formed between the back plates of adjacent boxes.

[0007] Preferably, the top plates of adjacent boxes are connected by additional connecting steel bars and structural steel bars.

[0008] Preferably, the back plate is a precast concrete slab, and the precast concrete slab is provided with horizontal distribution bars, vertical distribution bars and tie bars. The annular lap bar is embedded in the precast concrete slab, and the horizontal distribution bars pass through the annular lap bar.

[0009] Preferably, the precast concrete slab includes an edge member area located at a corner or joint, a connection area for connecting the box body on the same or upper / lower layers, and a ribbed area.

[0010] Preferably, the precast concrete slab is further provided with crack-resistant steel bars, one end of which is located in the top slab and the other end of which is located in the back slab.

[0011] Preferably, closed stirrups are provided in both the edge component area and the connection area, the arrangement density of closed stirrups in the edge component area is greater than that in the connection area, and concrete ribs are provided on the outer wall of the ribbed area.

[0012] Preferably, the back panel is provided with an additional connecting rib extending into it. The additional connecting rib is arranged perpendicular to the top panel and extends out of the back panel and into the back panel of the adjacent box located above the back panel.

[0013] Preferably, a second post-cast groove is formed between the back plate and the back plate of the adjacent housing located above the back plate.

[0014] Preferably, the arrangement density of the annular lap joints located in the side region of the back plate is greater than the arrangement density of the annular lap joints located in the middle region of the back plate.

[0015] This invention also discloses a back-to-back prefabricated module construction method, wherein the back-to-back prefabricated module as described above includes the following steps: When connecting the boxes on the same floor, one of the boxes is hoisted to the designated position, and the other box is vertically hoisted and the annular lapped bars on the adjacent back plates are brought into contact, and concrete is poured in the first post-pouring groove.

[0016] The present invention achieves the following technical effects compared to the prior art: By vertically placing the annular lap joints on the back plate, interference between the annular lap joints of adjacent boxes can be effectively avoided during hoisting, enabling smooth vertical hoisting and positioning of the boxes without the need for cumbersome lateral adjustments, thus significantly improving construction efficiency. Simultaneously, when adjacent boxes are placed side-by-side, the annular lap joints on their back plates contact each other and naturally enclose the space between adjacent back plates to form the first post-pouring groove for casting. This structure not only eliminates the need for formwork in the post-pouring area but also enhances the overall integrity and load-bearing capacity of the box connection through the annular lap joints, achieving a balance between construction convenience and structural reliability. It allows for precise connection between "back-to-back" boxes without the need for binding, improving connection efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Appendix Figure 1 This is a schematic diagram of the same-layer connection structure of the back-to-back assembled modules disclosed in this invention; Appendix Figure 2 This is a schematic diagram of the overall structure of the back-to-back assembled module disclosed in this invention; Appendix Figure 3 This is a top view structural diagram of the back-to-back assembled module disclosed in this invention; Appendix Figure 4 For the appendix Figure 3 Schematic diagram of the cross-sectional view at point AA; Appendix Figure 5 For the appendix Figure 3 Schematic diagram of the cross-sectional structure at point BB; Appendix Figure 6 This is a schematic diagram of the anti-crack steel reinforcement arrangement structure of the back-to-back assembled modular system disclosed in this invention. Appendix Figure 7 This is a schematic diagram of the upper and lower layer connection structure of the back-to-back assembled module disclosed in this invention. Appendix Figure 8 For the appendix Figure 7 Schematic diagram of the cross-sectional view at the CC section; Appendix Figure 9 For the appendix Figure 7 Schematic diagram of the cross-sectional structure at point DD; Appendix Figure 10 For the appendix Figure 7 Schematic diagram of the cross-sectional structure at the EE section; Appendix Figure 11 For the appendix Figure 7Schematic diagram of the cross-sectional view at the middle FF point; Appendix Figure 12 This is a schematic diagram of the same-layer connection node structure of the back-to-back assembled module disclosed in this invention. Among them, 1. Box body; 2. Top plate; 3. Back plate; 4. Circular lap joint bar; 5. Edge member area; 6. Connection area; 7. Ribbed area; 8. Crack-resistant reinforcement; 9. Extending additional connecting reinforcement; 10. Concrete rib; 11. Second post-cast groove; 12. Connecting reinforcement; 13. Non-connecting reinforcement; 14. Tie bar; 15. First post-cast groove; 16. Additional connecting reinforcement; 17. Structural reinforcement. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below 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.

[0020] The purpose of this invention is to provide a back-to-back assembled module and construction method that can achieve high connection accuracy between back-to-back modules without the need for binding, thereby improving connection efficiency.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] refer to Figures 1-12The back-to-back assembled module disclosed in this embodiment of the invention includes at least a box 1. The box 1 has a cubic or cuboid structure. The box 1 includes a top plate 2 and a back plate 3 disposed on the bottom circumferential direction of the top plate 2. The back plates 3 are connected end to end to form the box 1 structure. Each back plate 3 is provided with annular lap joints 4 for connecting adjacent boxes 1. The annular lap joints 4 are arranged vertically. The annular lap joints 4 on the back plates 3 of adjacent boxes 1 have their horizontal projections overlapping. A first post-cast groove 15 for casting is formed between the back plates 3 of adjacent boxes 1. By vertically arranging the annular lap joints 4 on the back plates 3, interference between the annular lap joints 4 of adjacent boxes 1 can be effectively avoided when hoisting the box 1 (if the annular lap joints 4 are arranged horizontally, interference between the annular lap joints 4 of adjacent boxes 1 can be effectively avoided). The horizontal placement of the annular lap joint 4 inevitably leads to interference issues during hoisting (requiring lateral adjustment of the box body 1). This allows for smooth vertical hoisting and positioning of the box body 1 without the need for cumbersome lateral adjustments, significantly improving construction efficiency. Furthermore, when adjacent box bodies 1 are placed side-by-side, the annular lap joint 4 on their back plates 3 contact each other and naturally enclose the adjacent back plates 3 to form the first post-pouring groove 15 for casting. This structure not only eliminates the need for formwork in the post-pouring area but also enhances the overall integrity and load-bearing capacity of the box body 1 connection through the annular lap joint 4, achieving a balance between construction convenience and structural reliability. It allows for precise connection between "back-to-back" box bodies 1 without the need for binding, improving connection efficiency.

[0023] It should be noted that the top slab 2 is preferably made of steel truss composite slab. For large spans, prestressed steel truss composite slabs can be used to achieve support-free installation. When there are requirements for pre-decoration of the bottom slab during the construction process, a bottom slab can also be added, achieving support-free installation, which significantly simplifies the construction process and improves efficiency.

[0024] refer to Figure 12 In one embodiment, the top plates 2 of adjacent box 1 are connected by additional connecting steel bars 16 and structural steel bars 17. By setting additional connecting steel bars 16 and structural steel bars 17 between the top plates 2 of adjacent box 1, a two-way collaborative steel bar connection system is constructed. This not only effectively enhances the integrity and continuity between the top plates 2, ensuring the uniform transmission of floor loads and the coordinated stress of the structure, but also simplifies the on-site binding operation, improves the quality of node connections and construction efficiency, and further enhances the overall stiffness and seismic performance of the modular building.

[0025] It should be noted that in the connection area of ​​the top plate 2, the additional connecting steel bars 16 and the structural steel bars 17 are set at the bottom of the top plate 2. The additional connecting steel bars 16 extend into the top plate 2 of the adjacent box body 1 by ≥1.2laE to ensure effective anchorage. The diameter of the structural steel bars 17 is not less than 6mm and the spacing is ≤300mm.

[0026] refer to Figure 7In one implementation method, the back plate 3 is a precast concrete slab. The precast concrete slab is equipped with horizontal distribution bars, vertical distribution bars, and tie bars 14. Circular lap bars 4 are embedded in the precast concrete slab and extend out of the precast concrete slab. By setting the back plate 3 as a precast concrete slab and embedding horizontal distribution bars, vertical distribution bars, and tie bars 14 inside it, a stable steel cage skeleton is formed, ensuring the structural strength and crack resistance of the back plate 3 itself. At the same time, the circular lap bars 4 are embedded in the precast concrete slab and extend out of the slab, realizing a firm connection between the connector and the precast component. This not only simplifies the on-site connection process but also achieves precise positioning and efficient connection between adjacent box bodies 1 through the outward-extending circular lap bars 4, further improving the integrity and construction quality of the modular building.

[0027] It should be noted that the vertical distribution bars do not extend beyond the back plate 3 and are arranged in a staggered pattern, divided into connecting bars 12 and non-connecting bars 13. The spacing of the circular lap bars does not exceed 600mm and can be arranged in a skip-step manner. By distinguishing the vertical distribution bars from the back plate 3 into connecting bars 12 and non-connecting bars 13 in a staggered pattern, the prefabrication and on-site hoisting processes are simplified, and the overall integrity of the wall is ensured through a reasonable bar layout. At the same time, the spacing of the circular lap bars 4 does not exceed 600mm. Combined with the skip-step arrangement, the on-site connection workload is greatly reduced while ensuring reliable structural connection, which significantly improves the construction efficiency, installation accuracy and structural synergy of modular buildings.

[0028] Among them, the connecting steel bar 12 is a vertical steel bar that bears the main tensile or compressive force transmission when the upper and lower box bodies 1 are connected, and the non-connecting steel bar 13 is a vertical steel bar that only plays a structural role in the box body 1 of this layer and does not participate in the force transmission between the upper and lower layers.

[0029] refer to Figures 7-11 As a preferred approach, the precast concrete slab includes an edge component area 5 located at corners or joints, a connection area 6 for connecting box 1s on the same or upper / lower floors, and a ribbed area 7. By dividing the precast concrete slab into the edge component area 5, the connection area 6, and the ribbed area 7, precise coordination of function and structure is achieved: the edge component area 5, through reinforcement and closed stirrups, ensures the seismic bearing capacity and structural integrity at corners and joints; the connection area 6 is dedicated to the docking of box 1s on the same or upper / lower floors, simplifying the on-site connection process and improving assembly accuracy and efficiency; the ribbed area 7, through local thickening or the addition of vertical ribs, significantly improves the lateral stiffness and deformation resistance of the wall panel without excessively increasing its self-weight. This zoning design not only optimizes the stress performance but also achieves efficient material utilization and convenient construction, comprehensively improving the reliability, economy, and industrialization level of modular buildings.

[0030] refer to Figures 4-6As a preferred approach, anti-crack steel bars 8 are also installed inside the precast concrete slab. One end of the anti-crack steel bars 8 is installed inside the top slab 2, and the other end is installed inside the back slab 3. By installing anti-crack steel bars 8 inside the precast concrete slab and anchoring one end to the top slab 2 and the other end to the back slab 3, a key force transmission and anti-crack connection path is constructed between the top slab 2 and the back slab 3. This effectively enhances the integrity of the corner area of ​​the box body 1 and can suppress stress concentration and crack propagation caused by temperature changes, shrinkage, or load at the junction of the top slab 2 and the back slab 3. This significantly improves the module's durability, waterproof performance, and the ability of the structure to work collaboratively under complex stress conditions.

[0031] It should be noted that the crack-resistant steel bar 8 has a three-section structure. The two sections at both ends are respectively set in the top plate 2 and the back plate 3 and are perpendicular to each other. The middle section is located at the corner and is arranged on an inclined plane. By designing the crack-resistant steel bar 8 as a three-section structure, with the two sections at both ends vertically anchored in the top plate 2 and the back plate 3 respectively, and the middle section arranged on an inclined plane at the corner, this structure precisely matches the stress distribution law of the corner area: the vertical sections at both ends effectively resist the bidirectional tensile stress of the top plate 2 and the back plate 3, while the inclined section in the middle directly faces the direction of the principal tensile stress, significantly inhibiting the generation and development of cracks in the 45° direction. Compared with traditional right-angle steel bars, this three-section design not only avoids stress concentration, but also optimizes the cooperative deformation ability of steel bars and concrete, and greatly improves the crack resistance, structural durability and overall stability of the corner of the box 1.

[0032] refer to Figures 7-11 As an implementation method, closed stirrups are provided in both the edge member area 5 and the connection area 6. The density of closed stirrups in the edge member area 5 is greater than that in the connection area 6. Concrete ribs 10 are provided on the outer wall of the ribbed area 7. By providing closed stirrups in both the edge member area 5 and the connection area 6, and designing the arrangement density differently for the two: the edge member area 5 uses denser closed stirrups to enhance seismic resistance and structural integrity, while the connection area 6 uses a moderate density to ensure connection reliability while taking into account economy and construction efficiency; at the same time, the concrete ribs 10 on the outer wall of the ribbed area 7 significantly improve the lateral stiffness and buckling resistance of the wall panel, realizing the coordinated design of "strengthening key areas, optimizing general areas, and reinforcing stiffness areas". Under the premise of ensuring structural safety, the material usage is optimized, the self-weight is reduced, and the industrialization efficiency and comprehensive performance of modular buildings are improved.

[0033] It should be noted that the thickness of the edge component area 5 and the connection area 6 is not less than 50mm, the thickness of the ribbed area 7 is 80mm, and the width of the concrete rib 10 should be determined according to the reinforcement layout.

[0034] refer to Figure 7As one implementation method, additional connecting bars are provided in the back plate 3. The additional connecting bars are set perpendicular to the top plate 2. The additional connecting bars extend out of the back plate 3 and into the back plate 3 of the adjacent box 1 located above the back plate 3. By setting additional connecting bars perpendicular to the top plate 2 in the back plate 3 and anchoring them into the back plate 3 of the adjacent box 1 above, a vertical direct force transmission path is constructed between the upper and lower box 1. This design effectively enhances the integrity and shear resistance of the inter-layer connection, ensures the continuous transmission of vertical loads, and improves the collaborative performance of the structure under horizontal loads through the anchoring effect of the additional bars. It not only simplifies the on-site connection process, but also further improves the assembly efficiency, structural reliability and seismic resistance of modular buildings.

[0035] It should be noted that the lap length of the additional connecting bars in the edge member zone 5 is not less than 1.6laE, and the lap length in the connection zone 6 is not less than 1.2laE. The additional connecting bars can be set as ring bars to reduce the lap length. By designing the lap length of the additional connecting bars in different zones according to the different stress areas: the lap length in the critical edge member zone 5 is not less than 1.6laE to ensure seismic safety and structural integrity; the lap length in the connection zone 6 is not less than 1.2laE to ensure reliable force transmission while taking into account construction efficiency and economy; at the same time, setting the additional connecting bars as ring bars effectively reduces the required lap length, further optimizes the node structure, accurately matches the stress requirements of each zone, and improves the connection reliability through the mechanical interlocking effect of the ring bars, reduces the amount of steel bars and space occupation, significantly improves the construction operability of densely reinforced areas, and achieves the unity of structural safety, economic efficiency and construction convenience.

[0036] refer to Figure 7 As one implementation method, a second post-pouring groove 11 is formed between the back plate 3 and the back plate 3 of the adjacent box 1 located above the back plate 3. By forming the second post-pouring groove 11 between the back plate 3 and the back plate 3 of the adjacent box 1 located above it, a vertical cast-in-place connection channel between the upper and lower box 1 is constructed. The post-pouring groove works in conjunction with the extended additional connecting bars to form an integral vertical force-bearing node after the concrete is poured. It not only effectively transmits and shares the vertical load and shear force, but also significantly enhances the integrity and seismic performance of the inter-layer connection. At the same time, the design of the second post-pouring groove 11 facilitates on-site pouring operations, simplifies the formwork process, improves construction efficiency, and further enhances the prefabrication level and structural reliability of modular buildings.

[0037] It should be noted that the first post-pouring tank 15 and the second post-pouring tank 11 are filled with high-strength micro-expansion grout or fine stone concrete.

[0038] This invention also discloses a back-to-back prefabricated module construction method, which, using the aforementioned back-to-back prefabricated modules, mainly includes the following steps: Vertical connection and assembly steps of upper and lower box 1 Applicable scenario: The lower box 1 is already in place, and the upper box 1 is being hoisted and connected; Lower layer preparation and exposed rebar: Complete the cavity pouring of the lower box 1 wall, ensuring that the reserved extended additional connecting steel bars 9 (ring steel bars) are exposed at the design position, and clean the surface of the steel bars of laitance and rust. Upper casing 1 hoisting and alignment: The upper box 1 is vertically lifted and slowly lowered to the predetermined position. The posture is adjusted so that the exposed additional connecting steel bars 9 of the lower box 1 accurately pass through the wall cavity at the bottom of the upper box 1 until the upper box 1 is completely placed on the designated support surface of the lower box 1. Overlap length check: Confirm that the lap length of the additional connecting steel bars 9 extending into the cavity in the upper and lower layers meets the seismic anchorage length required by the design. Second post-casting trench 11 is poured: In the second post-pouring groove 11 at the joint between the upper and lower box bodies 1, high-strength micro-expansion grout or self-compacting concrete is poured. During pouring, it should be ensured that it is vibrated and compacted (or the self-leveling properties are utilized) so that the grout fully wraps the reinforcing steel and forms an integral stress-bearing node.

[0039] Same-layer back-to-back box body 1 horizontal connection assembly steps Applicable scenario: Two adjacent boxes 1 are placed side by side on the same layer (back to back or side to side). Box 1 is hoisted into place: The adjacent box 1 is vertically lifted and directly lowered to the design position. Due to the exposed vertical ring steel bar design, there will be no horizontal steel bar interference during the descent of box 1, and no lateral pulling adjustment is required. Vertical ring-shaped reinforcing bars form lap joints: After the adjacent box 1 is in place, the back plates 3 of the two boxes 1 are closely aligned to form the connection area 6 of the middle back plate 3. At this time, the vertical ring steel bars exposed on the edge of the back plates 3 of the two sides naturally form an interlocking relationship in the pre-set connection area 6 of the back plates 3, thus constructing the skeleton of the horizontal force transmission path. Top slab reinforcement layout: Additional connecting steel bars 16 and structural steel bars 17 are laid on the top of box 1 (top plate 2 surface layer) to form a spatial steel mesh with the vertical ring steel bars, thereby enhancing the overall synergy; First post-casting groove 15 is poured: High-strength micro-expansion grouting material or self-compacting concrete is poured in the first post-cast groove 15 (wall side) and the post-cast area of ​​the top plate 2 at the joint of the same-layer box 1. After the grouting material reaches the design strength, the horizontal connection of the same-layer box 1 is completed.

[0040] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A back-to-back assembled module, characterized in that, The container includes a top plate and a back plate disposed on the bottom circumferential direction of the top plate. The back plate is provided with annular lap joints for connecting adjacent containers. The annular lap joints are arranged vertically, and the annular lap joints on the back plates of adjacent containers have horizontal projections that coincide. A first post-pouring groove for casting is formed between the back plates of adjacent containers.

2. The back-to-back assembled module according to claim 1, characterized in that, The top plates of adjacent boxes are connected by additional connecting steel bars and structural steel bars.

3. The back-to-back assembled module according to claim 1, characterized in that, The back plate is a precast concrete slab, and the precast concrete slab is provided with horizontal distribution bars, vertical distribution bars and tie bars. The annular lap bar is embedded in the precast concrete slab, and the horizontal distribution bars pass through the annular lap bar.

4. The back-to-back assembled module according to claim 3, characterized in that, The precast concrete slab includes an edge component area located at corners or joints, a connection area for connecting the box bodies on the same or upper / lower floors, and a ribbed area.

5. The back-to-back assembled module according to claim 4, characterized in that, The precast concrete slab is also equipped with crack-resistant steel bars, one end of which is located in the top slab and the other end of which is located in the back slab.

6. The back-to-back assembled module according to claim 5, characterized in that, Both the edge component area and the connection area are provided with closed stirrups. The arrangement density of the closed stirrups in the edge component area is greater than that in the connection area. Concrete ribs are provided on the outer wall of the ribbed area.

7. The back-to-back assembled module according to claim 1, characterized in that, An additional connecting rib is provided inside the back panel. The additional connecting rib is arranged perpendicular to the top panel. The additional connecting rib extends out of the back panel and into the back panel of the adjacent box located above the back panel.

8. The back-to-back assembled module according to claim 7, characterized in that, A second post-cast groove is formed between the back plate and the back plate of the adjacent box located above the back plate.

9. The back-to-back assembled module according to claim 1, characterized in that, The density of the annular lap joints located in the side region of the back plate is greater than the density of the annular lap joints located in the middle region of the back plate.

10. A back-to-back prefabricated modular construction method, comprising the back-to-back prefabricated module as described in any one of claims 1-9, characterized in that, Includes the following steps: When connecting the boxes on the same floor, one of the boxes is hoisted to the designated position, and the other box is vertically hoisted and the annular lapped bars on the adjacent back plates are brought into contact, and concrete is poured in the first post-pouring groove.

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