Assembled integral type anti-seismic reinforcing structure system of underground box type structure and construction method of assembled integral type anti-seismic reinforcing structure system

Abstract

The invention discloses an assembled integral type anti-seismic reinforcing structure system of an underground box type structure and a construction method, and belongs to the technical field of constructional engineering, the assembled integral type anti-seismic reinforcing structure system is arranged on the inner side of a wall plate of the existing underground box type structure (a piping shaft, a pool body, a cavern and the like), is composed of assembled type prefabricated modules and seam splicing modules, and is used for forming an integral structure with the four sides enclosed; the prefabricated modules are subjected to lightweight design; the splicing modules are used for connecting the adjacent prefabricated modules, and the connecting structure has the characteristic of staged implementation; the seam splicing module comprises a steel structure serving as a permanent and temporary combined component and post-pouring concrete poured in a cavity defined by the steel structure in the follow-up stage. The steel structure provides temporary connecting, fixing and size compensation functions in the initial installation stage, serves as a post-pouring special concrete formwork in the later transformation stage and is finally combined with concrete to form a steel-concrete composite structure joint. The structural system can effectively solve the prominent problems of long construction period, poor specification adaptability, insufficient shock resistance and the like in the transformation of the existing underground box type structure, and realizes quick, economical and high-reliability shock-resistant reinforcement in the conventional outage overhaul period.

Description

Technical Field

[0001] This invention belongs to the field of building engineering technology, and in particular relates to an assembled monolithic seismic reinforcement structure system and construction method for underground box-type structures. Background Technology

[0002] Existing underground box-type structures, such as various rectangular pipe shafts, small water tanks, and some underground facilities, were mostly constructed using masonry, plain concrete slabs, or plastic materials in the early days. With the development of engineering technology, this type of structure has gradually decreased, but due to the large existing stock and limited retrofitting conditions, many old box-type structures continue to be used. These structures were designed to lower standards at the time, and some no longer meet current specifications. Furthermore, they have generally experienced structural performance degradation during long-term service, creating potential engineering hazards. Especially for critical structures such as pipe shafts connected to urban lifeline systems, performance degradation could trigger systemic safety risks.

[0003] Underground box-type structures, especially smaller brick wells, plastic water tanks, and thin-walled concrete caverns that have been buried underground for a long time, commonly suffer from structural deformation, localized damage, and material aging. For these structures operating with defects, the preferred approach is complete demolition and reconstruction. However, in actual engineering projects, large-scale reconstruction is often difficult to implement due to factors such as project cost, operational characteristics, or technical feasibility. Therefore, structural reinforcement and renovation become the primary engineering strategy.

[0004] Currently, commonly used reinforcement methods mainly fall into two categories: cast-in-place and precast methods, which can achieve overall or partial reinforcement, respectively. Cast-in-place methods are generally reinforced concrete structures, with limited working space, long wet work cycles, and limited renovation periods. Precast methods are mostly steel structures, which are relatively easy to install but are susceptible to corrosion from the damp underground environment, and have higher overall costs, making them less applicable. Especially for underground small water tanks, pipe shafts, and other structures, the internal operating space is limited, and most require short-term shutdowns for renovation while maintaining operation under water conditions. The time window for construction is extremely limited, which further increases the difficulty of implementing conventional reinforcement technologies.

[0005] In summary, underground box-type structures (especially small and medium-sized structures) are generally reinforced and renovated using cast-in-place methods. However, these renovation schemes often focus on overall strengthening, failing to achieve precise reinforcement and structural optimization. Furthermore, they face numerous limitations in terms of cost, space, construction period, and operating conditions. Therefore, under current engineering technology conditions, the reinforcement of existing underground box-type structures still needs to be closely integrated with their structural characteristics and usage requirements, focusing on addressing prominent issues such as long renovation construction cycles, insufficient targeted structural reinforcement, and poor specification adaptability during large-scale renovations. Summary of the Invention

[0006] To address the problems of long construction cycles, insufficient targeted structural reinforcement, and poor specification adaptability in large-scale renovations of underground box-type structures in existing technologies, this invention provides an assembled integral seismic reinforcement structural system and construction method for underground box-type structures.

[0007] This invention is implemented as follows: a prefabricated, integrated seismic-resistant reinforcement structural system for underground box-type structures. The system is characterized by being located inside the wall panels of the box-type structure and consisting of prefabricated reinforced concrete modules and joint modules to form a four-sided enclosed integral structure. The joint modules connect adjacent prefabricated modules, and their connection structure allows for phased implementation. Each joint module includes a steel structure serving as a permanent-temporary connecting component, and a post-cast special concrete poured into the enclosed cavity of the steel structure in subsequent stages. During the initial installation stage, the steel structure acts as the main dry connection component, providing connection and fixation, and together with the self-stabilizing original enclosure structure, forms the enclosure structure for this stage. The steel structure has dimensional compensation capabilities and, in the final structure, forms a steel-concrete composite structural node together with the post-cast special concrete.

[0008] In the above technical solution, preferably, the end of the prefabricated module is provided with an end structure, the end structure including double-sided embedded steel plates arranged along the vertical edge, outwardly extending horizontal reinforcing bars, and interface treatment measures for enhancing the bonding and interlocking of new and old concrete; the interface treatment measures for enhancing the bonding and interlocking of new and old concrete include roughening treatment, pre-set keyways, or pre-coating interface agent.

[0009] In the above technical solution, preferably, the prefabricated module has a variable thickness design, with its edge structure dimensions remaining unchanged but its construction strengthened, while the thickness dimension of its middle structure is optimized and reduced.

[0010] In the above technical solution, preferably, the thinning position of the intermediate structure adopts the form of an inner flat and outer concave side or an outer flat and inner concave side, depending on the engineering requirements.

[0011] In the above technical solution, preferably, the splicing module is located at the corner of the wall panel of the underground box structure, and a composite reinforcement node is constructed at this location.

[0012] In the above technical solution, preferably, the steel structure in the splicing module includes an L-shaped mounting steel plate for welding and fixing to the pre-embedded steel plate of the prefabricated module, and steel supports disposed on the inner sides of the mounting steel plate in two directions. The mounting steel plate is provided with reserved holes for welding.

[0013] In the above technical solution, preferably, the post-cast special concrete has self-compacting properties, micro-expansion properties, and underwater casting properties.

[0014] The beneficial effects created by this invention are mainly reflected in the following aspects: The splicing method of this invention can be dynamically adjusted according to the engineering stage and functional requirements, realizing functional connection and performance synergy at different stages throughout the entire life cycle of the project. In the one-time molding stage, the splices adopt dry connection, making construction efficient and convenient. The steel structure at the splice, as the main structure of the dry connection, has dimensional compensation characteristics, effectively solving the contradiction between the standardization of component disassembly specifications and the diversification of structural combination dimensions in large-scale renovation. In the node strengthening stage, the splices switch to wet connection. The steel structure follows the permanent-temporary combination design concept, also serving as a casting formwork. With the help of special materials, this stage can be carried out under water conditions during the operation period. The permanent-temporary combination design adjusts the connection process into a parallel process, solving the problem of excessively long curing time for integral concrete structures in cast-in-place methods, thereby significantly saving construction time and even enabling the completion of the entire renovation within the regular shutdown and maintenance period.

[0015] In terms of the structural system, this invention, based on structural stress characteristics and production requirements, prioritizes the placement of joints in key areas such as corners, and divides the main enclosure structure into several standardized straight-panel components. Compared to the integrated structure of prefabrication methods, this solution significantly simplifies the component forms, making production, transportation, and construction easier. Specifically, the principle of prefabricated module division is based on the common standard dimensions of the objects undergoing large-scale renovation, thereby determining the optimal specifications and quantity of prefabricated components, adaptable to the renovation of structures with diverse specifications. This standardized division not only simplifies the component forms but also significantly improves factory production efficiency and economies of scale.

[0016] The steel structure follows a combined permanent and temporary design concept, with targeted reinforcement of weak areas such as corners, significantly improving the structure's seismic performance. This invention differs from traditional uniform reinforcement methods, representing a differentiated design based on specific needs. Targeted reinforcement (increasing the steel content of the structure) of weak and critical areas such as corners results in structural performance superior to conventional cast-in-place structures. Optimization of plate thickness in low-stress zones within precast components, a lightweight design, effectively saves building materials and facilitates on-site hoisting operations. Furthermore, the thinning of precast components reduces the amount of internal wall panel treatment work required for existing underground box-type structures or saves effective volume within the underground box-type structure.

[0017] In summary, this invention addresses the prominent problems of existing underground box-type structure reinforcement technologies, such as long renovation and construction cycles, insufficient targeted reinforcement, and poor specification adaptability during large-scale renovations. It proposes a complete and systematic solution. The solution employs a prefabricated integral structural system, integrating dynamic adjustability and performance-oriented design concepts into the joint construction and prefabricated component design. Through key technologies such as permanent-temporary combination and lightweighting, it significantly reduces construction time and costs. This solution overcomes the limitations of long construction cycles in cast-in-place methods in terms of time and breaks through the constraints of multi-specification structures in terms of space. This makes large-scale renovation of underground box-type structures feasible within limited downtime, providing a solid technical guarantee for the safe, stable, and long-term operation of the structural system.

[0018] A prefabricated monolithic seismic reinforcement construction method for underground box-type structures includes the following steps: One-time molding stage: a. hoisting and positioning the prefabricated module; b. installing the steel structure and using the steel structure to compensate and adjust the size of the underground box-type structure; c. using dry connection to connect the steel structure to adjacent prefabricated modules to form a temporary structure that meets the requirements of normal use conditions; Node reinforcement stage: a. The steel structure is used as a template to form a closed cavity together with the ends of the prefabricated modules; b. Special concrete is poured into the cavity to form a steel-concrete composite structure; c. The steel-concrete composite structure serves as a permanent structure to bear loads and meet the safety requirements under special earthquake conditions.

[0019] In the above technical solutions, preferably, the dry connection in the one-time molding stage adopts welding process, or adopts dry connection methods such as bolt connection, plug connection or flange.

[0020] In the above technical solution, preferably, the welding process includes: adding a reinforcing weld at the reserved opening position of the outer steel plate to improve the welding arrangement and increase the total length of the weld.

[0021] In the above technical solution, preferably, the one-time forming stage involves connecting the horizontal outward reinforcing bars corresponding to adjacent prefabricated components after the prefabricated module is hoisted and positioned.

[0022] In the above technical solution, preferably, the node strengthening stage is carried out continuously after the completion of the one-time molding stage. If the object of the renovation is a water-bearing operational structure with a limited renovation period, the node strengthening stage can be implemented under water-bearing conditions during the operation period.

[0023] In the above technical solution, preferably, the node strengthening stage is carried out by pouring special concrete, so that the curing of the special concrete and the operation of the structure with water can be carried out in parallel, thereby solving the problem of limited construction period for the renovation of such structures. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the side shape of the prefabricated module in this invention; Figure 2 This is a schematic diagram of the installation structure of the prefabricated module in this invention; Figure 3 This is a schematic diagram of the reinforced structure system architecture described in this invention; Figure 4 yes Figure 3 Enlarged view of part A; Figure 5 This is a side view of the connection structure between the splicing module and the prefabricated module in this invention; Figure 6 This is a three-dimensional view of the seam module setting position in this invention; Figure 7 This is a schematic diagram of the reinforced structure system architecture described in Embodiment 3 of this application. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] This invention provides a prefabricated, monolithic seismic-resistant reinforcement structural system and construction method for underground box-type structures. To further illustrate the structure of this invention, a detailed description is provided below in conjunction with the accompanying drawings: Example 1 This embodiment discloses a prefabricated monolithic seismic reinforcement structural system for underground box-type structures. Its core objective is to improve the engineering function and structural performance of existing underground box-type structures while addressing issues such as long renovation construction cycles, insufficient targeted structural reinforcement, and poor specification adaptability during large-scale renovations. Please refer to... Figures 1-6 The structural system is located inside the wall panel 3 of the box-shaped structure and consists of prefabricated reinforced concrete modules 1 and splicing modules 2, ultimately forming a four-sided enclosed, reinforced structure. The key innovation of this system lies in its systematic splicing design, which enables targeted functions at different stages.

[0027] Precast modules are the main component of the reinforced structure. They are standardized reinforced concrete straight slab members that allow the enclosure structure to be broken down into simple, easy-to-manufacture straight slab units. The precast modules employ a variable thickness design; the dimensions of the edge structure 1-1 remain unchanged but the construction is strengthened, while the thickness of the middle structure 1-2 is optimized and reduced. This design achieves lightweighting while ensuring structural safety, effectively avoiding material waste and design redundancy, and facilitating transportation and on-site hoisting. The straight slab members are pre-installed and embedded according to project requirements.

[0028] The prefabricated modules, with their variable thickness design, not only reduce weight and installation difficulty but also offer higher torsional resistance compared to rectangular sections of the same area. Based on the structural stress model, the thickness of the central region of the panels can be optimized and reduced. The thinning points in the intermediate structure can be determined by site conditions, employing either an "inner flat, outer concave" side profile (to reduce processing work if the original wall panel surface is uneven and difficult to treat) or an "outer flat, inner concave" side profile (to save effective space within the underground box-type structure if the structure has strict requirements for internal clearance).

[0029] The end structure of the precast module needs to take into account both installation and structural provisions, including: double-sided embedded steel plates 1-3 set along the vertical edge to provide accurate and reliable connection conditions; horizontally extending reinforcing bars 1-4 to ensure reliable load transfer and joint bearing capacity, and ensure the continuity of internal force transmission; and interface treatment measures required for wet connection, including roughening treatment, setting keyways, and applying interface agent to enhance the bonding and interlocking between new and old concrete.

[0030] The splice module is used to connect adjacent prefabricated modules. Its connection structure features phased implementation, with vertical splices placed at the corners of the box-type structural panels. Composite reinforcement nodes are constructed at these locations to specifically improve the overall seismic performance of the structure. The splice module includes a steel structure serving as a permanent-temporary joint component and post-cast special concrete 2-1. The steel structure includes an L-shaped mounting steel plate 2-2 for welding and fixing to the prefabricated module's embedded steel plate, and steel supports 2-3, preferably steel profiles, located on the inner sides of the mounting steel plate or embedded steel plate in two directions to improve the stiffness of the splice module in the initial stage. The outer surface of the mounting steel plate has pre-drilled holes 2-4 to increase the number and total size of on-site welds, ensuring reliable force transmission at the nodes. Several steel supports are vertically positioned at the corners of the mounting steel plate. The embedded steel plates of adjacent prefabricated components in the steel structure can also be designed for direct overlap and connection, in which case additional mounting steel plates are unnecessary.

[0031] The steel plates and profiles of the steel structure are permanent and temporary combined components. Initially, they serve as temporary connections and construction measures, but later, they participate in joint stress during seismic conditions. Material grades and dimensions must meet overall seismic resistance requirements. In this embodiment, L-shaped installation steel plates form vertically extending inner and outer double plates. The inner and outer L-shaped installation steel plates are respectively connected to the inner side of the prefabricated module's embedded steel plates, forming a closed cavity for subsequent concrete pouring. The post-poured special concrete must possess self-compacting properties (able to fully fill the narrow space enclosed by the steel structure by its own weight without vibration), micro-expansion properties (generating moderate volume expansion during setting to enhance internal density and improve bonding with interfaces), and underwater pourability (possessing the ability to hydrate and harden normally in humid or wet environments, and continuously developing strength during water operation after 8–12 hours of final setting).

[0032] Example 2 This embodiment details a prefabricated, integrated seismic reinforcement construction method for box-type structures. The key lies in dividing the joint construction into a one-time forming stage and a node reinforcement stage, adjusting the preceding and following processes into parallel processes to complete the renovation within the regular maintenance period. Before large-scale renovation implementation, it is necessary to conduct dimensional consolidation and statistics on the target structures (such as pipeline wells in the renovation area), merging similar specifications to reduce the types of prefabricated components and improve prefabrication efficiency.

[0033] One-time molding stage (temporary connection): In this stage, the joints are temporary measures, the connection structure is a steel structure, and the connection method is a dry connection. The design goal is to meet the structural stability and connection requirements under normal operating conditions.

[0034] First, the top cover of the structure was removed, and then the prefabricated modules on all four sides were hoisted and placed in place.

[0035] Then the steel structure is installed, and the steel structure is used to compensate and adjust the dimensions of the existing structure to adapt to the differences in planar dimensions of the existing structure due to construction deviations and usage deformation, so that the standardized prefabricated modules can be applied to structures with diverse dimensions.

[0036] The steel structure is connected to the adjacent prefabricated modules using dry connection methods (such as welding, bolting, plugging, or flanges) to form a temporary structure.

[0037] The dry connection in the one-time molding stage is not only convenient to construct and saves time, but its steel structure, as a temporary structure, itself provides a high-precision, non-removable formwork system (outer steel plate enclosure and inner steel consolidation) for the subsequent wet connection. This makes the construction quality of the subsequent wet connection more stable and greatly reduces the dependence on waterproofing and dimensional control in on-site operations.

[0038] If welding is used, the main steps are as follows: Align the inner and outer double plates of the steel structure with the pre-embedded steel plates facing each other on the precast components and fit them tightly together. Then, continuously weld along all contact edges to form edge welds, i.e., continuous welds 6. Add reinforcing welds 5 at the reserved openings of the outer steel plate installation, changing the overall welding method from a linear one-dimensional arrangement to a two-dimensional arrangement on the surface, increasing the number of welding points and weld length, and ensuring reliable load transfer. The construction operation can proceed in the following sequence: After hoisting and positioning the precast module, attach the outer installation steel plate to the inner side of the precast module's embedded steel plate and weld them together; connect the corresponding horizontal outward-extending reinforcing bars of adjacent precast components; attach the inner installation steel plate to the inner side of the embedded steel plate and weld them together.

[0039] Node reinforcement stage (permanent connection): In this stage, the joints are permanent, the connection structure is a steel-concrete composite structure, and the connection method is wet connection. The design goal is to meet the safety requirements under special seismic conditions. This stage is preferably carried out continuously after the completion of the initial molding stage. If the object being modified is a water-bearing operational box-type structure (such as a pipe well or water tank) with a limited renovation period, the node reinforcement stage can be implemented under water-bearing conditions during the operational period.

[0040] First, the steel structure is used as a template, and together with the ends of the prefabricated modules, they form a closed cavity.

[0041] Secondly, special concrete is poured into the cavity to form a steel-concrete composite structure that encloses the steel structure and the end structure of the prefabricated module.

[0042] The steel plates and structural steel sections of the steel structure, together with the post-cast special concrete, serve as permanent structural elements to bear the load, enabling the performance of the joint structure to reach a level "superior to cast-in-place".

[0043] This system targets structures operating under water conditions. By optimizing the structure, it changes the process of concrete curing during the construction phase and water-operated operation during the operation phase from sequential to parallel, thereby significantly shortening the construction period.

[0044] Because special concrete can be poured underwater and has self-compacting properties, the joint reinforcement stage is almost unaffected by the damp or watery environment and narrow space on site. It can even be implemented in water-filled conditions when the structure is restored to water operation, which greatly saves the renovation period.

[0045] Example 3 Please see Figure 7This embodiment discloses a feasible implementation of the present invention, namely, an L-shaped corner prefabricated component assembly method, which aims to shift the construction risk of the weakest corner area of ​​the structure to a controllable factory production stage. Specifically, if cast-in-place construction is used, the on-site operation skills required are high. By prefabricating the reinforcement structure of this weak area, especially using the L-shaped corner prefabricated component scheme, a seamless integral structure is achieved in the weakest corner area of ​​the structure, and the joint is located at the position of minimum horizontal bending moment. This effectively shifts the uncontrollable on-site construction risk to a controllable factory production stage, thereby ensuring the structural reliability and quality accuracy of key components.

[0046] This design combines L-shaped corner prefabricated components with straight panel prefabricated components. Specifically, the corner sections of the reinforced structure are designed as integrally prefabricated L-shaped components 4, while the middle sections of the structure's wall panels are designed as straight prefabricated components (for large structures, the middle section is divided into several straight prefabricated components), i.e., prefabricated modules, all of which are formed in one piece in the factory. All joints use straight joint modules with dimensional compensation functions.

[0047] L-shaped prefabricated components fully utilize the advantages of factory prefabrication, achieving a seamless integral structure in the weakest corner area, significantly improving the structural performance of this region. This component can be structurally strengthened, for example, by appropriately increasing the reinforcement ratio. The prefabricated components continue to implement the lightweight design concept, optimizing the slab thickness of the central structure. The joint modules continue the aforementioned implementation method, divided into a primary forming stage (dry connection) and a secondary strengthening stage (wet connection). Since the joint modules are located at the location of minimum horizontal bending moment under lateral pressure, where the bending moment is very small or even zero, the steel plate parameters in the dry connection can be designed to meet normal service conditions without needing to be specially increased for seismic conditions. The straight-line joint modules use dry connection in the primary installation stage; the steel structure, as a permanent-temporary combined structure, has dimensional compensation capabilities and can adapt to dimensional deviations of different structures. In the node strengthening stage, wet connection is used as a structural component combining permanent and temporary elements, ensuring its participation in the overall node load-bearing and seismic resistance through concrete pouring. When the base plate of a structure needs to be modified or the structure strengthened simultaneously, prefabricated components and splicing connection schemes consistent with the wall panel structure can be used to form a complete prefabricated assembly system.

[0048] In summary, this invention, through its prefabricated integrated structural system, integrates dynamic adjustability and performance-oriented design concepts in the joint construction and prefabricated component design. By employing key technologies such as permanent-temporary combination and lightweighting, it significantly reduces construction time and costs, providing a solid technical guarantee for the safe, stable, and long-term operation of urban underground pipeline systems.

[0049] The first embodiment described in this paper prioritizes the placement of splice modules in critical areas such as corners, employing a combined permanent and temporary steel-concrete composite structure for specialized reinforcement, achieving a structural performance superior to conventional cast-in-place construction. The third embodiment utilizes L-shaped corner prefabricated components, placing the splice modules at locations with minimal horizontal bending moments under lateral pressure—that is, areas where positive and negative bending moments increase, and regions with very small or even zero bending moments. This revelation of mechanical principles is a key aspect of the invention's inventiveness. When the splice is placed in a low-bending-moment zone, the steel plate parameters in the dry connection can be designed to meet normal operating conditions without requiring special increases for seismic conditions, thereby achieving further structural lightweighting and economy. This represents a revolutionary improvement over existing splice design concepts.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A prefabricated integral seismic reinforcement structural system for underground box-type structures, characterized in that, The structural system is located inside the wall panels of the underground box-type structure and consists of prefabricated reinforced concrete modules and joint modules to form a four-sided enclosed overall structure, wherein: The seam module is used to connect adjacent prefabricated modules, and its connection structure is characterized by phased implementation; The splicing module includes a steel structure as a permanent-temporary joint component, and post-cast concrete poured into the enclosed cavity of the steel structure in a subsequent stage. The steel structure provides temporary connection, fixation and dimensional compensation functions during the initial installation phase, and together with the post-cast concrete in the final structure, it forms a steel-concrete composite structure node.

2. The assembled monolithic seismic reinforcement structural system according to claim 1, characterized in that, The prefabricated module has an end structure at its end, the end structure including: Double-sided embedded steel plates are installed along the entire length of the vertical edge; Horizontal outward-extending reinforcing bars; Interface treatment measures used to enhance the bond and interlocking of new and old concrete include roughening treatment, pre-set keyways, or pre-coating with an interface agent.

3. The prefabricated integral seismic reinforcement structural system according to claim 1 or 2, characterized in that, The prefabricated module is designed with variable thickness. Its edge structure dimensions remain unchanged but are reinforced, while the thickness of its middle structure is optimized and reduced.

4. The assembled monolithic seismic reinforcement structural system according to claim 3, characterized in that, The thinning position of the intermediate structure can be either an inner flat and outer concave side or an outer flat and inner concave side, depending on the engineering requirements.

5. The prefabricated integral seismic reinforcement structural system according to claim 1, characterized in that, The splicing module is located at the corner of the wall panel of the underground box structure, and a composite reinforcement node is constructed at this location.

6. The prefabricated integral seismic reinforcement structural system according to claim 1, characterized in that, The steel structure in the splicing module includes: L-shaped mounting steel plate for welding and fixing to the prefabricated module embedded steel plate; Steel supports, preferably steel structural members, are provided on the inner sides of the mounting steel plate in two directions to improve the rigidity of the splicing module in the early stage and the integrity in the later stage; the mounting steel plate is provided with reserved holes for welding.

7. The prefabricated integral seismic reinforcement structural system according to claim 1, characterized in that, The post-cast concrete is a special type of concrete, which has self-compacting properties, micro-expansion properties, and the ability to be poured underwater.

8. A prefabricated integral seismic reinforcement construction method for underground box-type structures, characterized in that, Includes the following steps: One-time molding stage: a. Hoisting and positioning the prefabricated module; b. Install the steel structure and use it to compensate for and adjust the dimensions of the underground box-type structure, and connect the horizontal outward reinforcing bars of adjacent precast components; c. The steel structure is connected to the adjacent prefabricated modules using a dry connection method to form a temporary structure that meets the requirements of normal use conditions; Node strengthening phase: a. Use the steel structure as a template to form a closed cavity together with the ends of the prefabricated modules; b. Special concrete is poured into the cavity to form a steel-concrete composite structure; c. The steel-concrete composite structure serves as a permanent structure for load-bearing, meeting the safety requirements under special earthquake conditions.

9. The construction method according to claim 8, characterized in that, The dry connection in the one-time molding stage adopts welding process, or dry connection methods such as bolt connection, plug connection or flange.

10. The construction method according to claim 9, characterized in that, The welding process includes the following steps: setting a continuous weld at the intersection of the edge of the mounting steel plate and the embedded steel plate; adding a reinforcing weld at the reserved opening of the outer mounting steel plate to improve the welding arrangement and increase the total length of the weld.

11. The construction method according to claim 8, characterized in that, The first-stage molding process involves connecting the horizontal outward-extending steel bars corresponding to adjacent precast components after the precast module is hoisted into place.

12. The construction method according to claim 8, characterized in that, The node reinforcement stage is preferably carried out continuously after the completion of the one-time molding stage. If the object of the renovation is a water-bearing operational structure with a limited renovation period, the node reinforcement stage can be implemented under water-bearing conditions during the operation period.

13. The construction method according to claim 8, characterized in that, The node reinforcement stage involves pouring special concrete, which allows the curing of the special concrete to be carried out in parallel with the operation of the structure while it is wetted.

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