Fabricated wall-plate abutted seam shear-resistant connecting system

Abstract

The invention discloses a fabricated wall-plate abutted seam shear connection system, and belongs to the technical field of fabricated concrete structures. According to the system, a local vertical hole channel penetrating through a wall-plate interface is formed near a horizontal abutted seam of a prefabricated shear wall and a prefabricated floor slab or a laminated slab, steel bearing plates are arranged at the upper end and the lower end of the hole channel, a high-strength prestress pull rod is arranged in a penetrating mode, the two ends of the hole channel are locked through anchorage devices and nuts, and the adjustable axial pressure device with the stroke compensation capacity is formed. The axial pressure device is arranged near the connecting box or the sleeve grouting connecting piece, and the shear friction bearing capacity and the energy dissipation capacity are improved. In the construction stage, target axial pressure is set by tightening a nut, and axial pressure attenuation caused by prestress loss and interface cracking is compensated. The axial compression ratio passively formed by the whole structure is converted into the local normal pressure capable of being designed in the node layer, and the method is suitable for different design of shear resistance of different wall section interfaces and is different from a traditional prestress system crossing the whole wall.

Description

Technical Field

[0001] This invention relates to the field of prefabricated concrete structure technology, specifically to a shear-resistant connection system for horizontal joints between precast shear walls and precast floor slabs or composite slabs, and more particularly to a prefabricated wall-panel joint shear-resistant connection system that adjusts the interface normal pressure, improves shear friction bearing capacity and energy dissipation capacity by locally adding an adjustable vertical prestressing device at the wall-panel node. Background Technology

[0002] Prefabricated shear wall structures utilize prefabricated wall panels, floor slabs, and other components in a factory, achieving overall connection on-site through wet joints, sleeve grouting, and connectors. They offer advantages such as high industrialization and rapid construction. Vertical joints between wall panels and horizontal joints between wall panels and floor slabs are crucial in determining the structural integrity and seismic performance.

[0003] In existing technologies, the connection methods for vertical and horizontal joints in precast shear walls mainly include: grouting connection with steel sleeves, grout anchoring connection, reinforcement anchoring of cast-in-place composite layers, setting shear keys or grooves, and local steel plate connections. For example, a literature discloses a vertical joint connection structure for precast shear walls that achieves reliable connection between wall panels through steel sleeves and post-cast concrete, improving load-bearing capacity and ductility. Other technologies improve overall stiffness and self-centering capacity by setting prestressed tendons that penetrate the height of the shear wall.

[0004] For wall-panel joints, current standards and research mostly adopt the following methods: achieving overall connection of the joint by inserting reinforcing bars and sleeves into the floor slab composite layer and wall panel; achieving shear and slip resistance by roughening the interface and using shear grooves in conjunction with vertical reinforcing bars; and in a few self-resetting systems, using vertical prestressed tendons that run through the entire height of the wall to make the wall-panel joint bear the force as a whole with the wall base.

[0005] Numerous studies and design codes have shown that the axial compression ratio of concrete members has a significant impact on the shear capacity, deformation capacity, and anti-slip performance of shear walls. For precast interfaces designed using shear friction theory, their shear capacity can typically be simplified as follows: ,in: This is the design value for the interface shear capacity; The reference shear capacity of concrete without considering additional normal pressure; The interfacial friction coefficient; The design value for the normal pressure acting on the interface; The shear capacity contributed by the reinforcing bars or pins passing through the interface.

[0006] In existing prefabricated shear wall structures, the normal pressure acting on the wall-panel joints Primarily determined by the overall structural stress state (dead load, live load, force transmission path between the upper walls and floors, etc.), it can only be indirectly affected by changing the overall structural layout, component dimensions, or load combinations. It is difficult to achieve precise and controllable design of the normal pressure at individual joint interfaces at the node construction level. This results in: difficulty in configuring the interface axial compression level specifically according to the seismic response characteristics and failure modes for different floors and wall sections; and an inability to effectively compensate for the reduction in axial compression caused by concrete shrinkage and creep, steel relaxation, and crack development during long-term use, thus affecting long-term shear capacity and energy dissipation performance.

[0007] In recent years, scholars both domestically and internationally have proposed various systems for improving the seismic performance of prefabricated structures by utilizing prestressing and energy dissipation devices. For example, vertical prestressing tendons running through the entire wall can be used to create self-centering prefabricated shear walls, or disc spring devices can be installed at the ends of prefabricated frame beams to improve joint ductility and energy dissipation capacity. Related research shows that disc spring assemblies have high energy dissipation capacity and controllable stiffness-stroke characteristics, making them suitable for combination with prestressing systems for self-centering and energy dissipation design of seismic joints.

[0008] However, the above-mentioned technologies have the following characteristics and limitations: prestressed tendons are mostly long prestressed systems that run through the entire height of the wall or the span of a large component, and their tensioning and anchoring depend on the end anchorage zone, which places high demands on the prefabrication of components in the factory and on-site construction; disc spring devices are mostly arranged at the ends of beam-column joints to control the rotation and restoring force characteristics of the beam ends, and there is no specific design for adjustable normal pressure at the wall-panel horizontal joint interface; in the existing literature, there is no vertical prestressed-disc spring combination structure that only crosses a local joint near the wall-panel joint, has a short stroke, and aims to control the shear friction bearing capacity of a single interface.

[0009] In summary, although existing technologies recognize the significant impact of axial compression ratio and interfacial normal pressure on the shear capacity and ductility of prefabricated wall-panel joints, and have explored the use of prestressing and disc springs to improve the seismic performance of joints, the following problems still urgently need to be addressed:

[0010] (1) In the existing system, the axial compression ratio is mainly determined by the overall stress state of the structure. There is a lack of means to quantitatively control the normal pressure of the interface of a single wall-panel joint at the node construction level, making it difficult to carry out differentiated design according to the performance objectives of different floors and different wall sections.

[0011] (2) The traditional prestressed system that runs through the whole wall has a long stroke and complex construction process. Moreover, its prestress mainly acts on the whole wall, making it difficult to form a special control over the normal pressure of a single wall-panel joint interface.

[0012] (3) Existing disc spring devices mostly serve the bending behavior of beam-column joints and have not yet been combined with the shear friction-pin joint stress mechanism of prefabricated wall-panel joints. There is a lack of a locally adjustable axial pressure structure that can restore the design axial pressure level through simple operation after service and earthquake.

[0013] Therefore, it is necessary to propose a local vertical prestressed disc spring combination structure specifically designed for prefabricated wall-panel interfaces, which has a short stroke, only crosses local joints, and can adjust the interface normal pressure during construction and service. This structure should work in conjunction with existing interface connectors such as connecting boxes / sleeves to improve the interface shear friction bearing capacity, energy dissipation capacity, and long-term performance while ensuring construction feasibility. Summary of the Invention

[0014] The purpose of this invention is to address the problem that the interfacial normal pressure in existing prefabricated wall-panel joints is mainly passively formed by the overall stress state and is difficult to quantitatively control at the node level. This invention proposes an adjustable axial pressure device locally added to the wall-panel joint, enabling the design and adjustment of the normal pressure at the wall-panel joint interface. This, in turn, improves the interfacial shear friction bearing capacity and energy dissipation capacity; allows for differentiated shear performance design at different floors and wall segments within the same structure; and compensates for the reduction in axial pressure caused by long-term relaxation, concrete shrinkage and creep, and crack development, thereby improving the long-term and post-earthquake performance of the structure.

[0015] To achieve the above objectives, the present invention adopts the following overall technical solution:

[0016] Near the wall-panel joint interface (3) between the precast shear wall panel (1) and the precast floor slab or composite slab (2), several vertical perforations are reserved, and vertical channels (6) are formed using metal corrugated pipes, etc.; upper bearing steel plates (7) and lower bearing steel plates (8) are pre-embedded at the upper and lower ends of the vertical channels (6) respectively, so that the bearing steel plates are reliably anchored to the concrete of the component; high-strength prestressed tie rods or short bundles (9) are inserted into the vertical channels (6), and anchorages and end nuts (11) are configured at both ends, and disc spring groups (12) are arranged between the nut at at least one end and the corresponding bearing steel plate to form a vertical axial compression device with displacement tolerance and adjustable stiffness; vertical channels ( 6) Arranged inside the wall-panel joint interface (3) and adjacent to the connecting box (4) or grouting sleeve (5) in the plane, so that the axial tension generated by the high-strength prestressed tie rod (9) directly presses the concrete on both sides of the wall-panel interface through the bearing steel plate, thereby increasing the interface normal pressure; during the construction stage, by controlling the tension or end tightening torque of the high-strength prestressed tie rod (9), the disc spring group (12) reaches the design compression amount, thereby establishing the target normal pressure at the interface; after service or earthquake, the stress of the tie rod is re-measured through the inspection hole (13), and if necessary, the nut can be tightened again or the disc spring group can be replaced to restore or adjust the interface normal pressure.

[0017] Adjustable axial compression-interface shear capacity relationship combined with design methodology

[0018] Based on the interface shear design concept of decomposition of shear friction and pin action, the shear bearing capacity of the wall-panel joint interface in this invention can be designed by the following formula:

[0019]

[0020] in: Design value of interface shear bearing capacity; The reference shear capacity of the concrete interface without the application of additional axial compression can be determined based on the interface roughness and concrete strength. : Coefficient of interfacial friction; Design value of normal pressure transferred to this interface by the structure's self-weight and vertical load (obtained from overall structural analysis); The additional normal pressure design value provided by the locally vertically adjustable axial pressure device of the present invention; Shear capacity provided by steel bars, pins, or connectors passing through the interface.

[0021] The key to this invention lies in the direct control via an adjustable axial pressure device. The interface normal pressure, which can only be passively accepted in the traditional design, is transformed into an adjustable parameter, thereby increasing the interface shear bearing capacity. The configuration can be "reverse-calculated" and optimized based on the target performance. Specifically, you can follow these steps:

[0022]

[0023] This determines the target additional normal pressure for each interface. Then, based on the number of prestressed tie rods and the arrangement of disc spring assemblies, determine the design axial force of a single tie rod. .

[0024] Disc spring assembly design and axial force-displacement relationship

[0025] The function of the disc spring assembly (12) is to convert the tension provided by the prestressed tie rod into a clamping force on the bearing steel plate, and to keep the axial force within an acceptable range when relative displacement occurs at the wall-plate joint due to cracking, rotation, vibration, etc. For a single vertically adjustable axial compression device, it can be approximately expressed as:

[0026]

[0027] in: In relative displacement Under certain conditions, the axial pressure exerted by the disc spring assembly on the interface; The equivalent stiffness of a disc spring assembly is determined by the series and parallel combination of disc springs. : Axial pressure under initial compression.

[0028] Design control is achieved through the following methods: tandem disc springs increase total stroke, reduce stiffness, and improve displacement tolerance; parallel disc springs increase stiffness and improve axial force levels; and the equivalent stiffness is comprehensively determined by combining structural displacement requirements and prestress loss predictions. Total Itinerary .

[0029] Compared with existing prefabricated shear wall and prestressed wall systems, this invention has the following significant advantages and inventive features:

[0030] (1) Convert the overall axial compression ratio into adjustable local axial compression: By setting a short-stroke local prestressed disc spring device near the wall-panel joint, the axial compression ratio originally given by the overall structural analysis is converted into a local normal pressure that can be independently designed and controlled on a single interface, thus realizing a two-level axial compression design system of "overall structure - local node".

[0031] (2) Special structure for prefabricated wall-panel interface: The prestressed tie rod of the present invention only spans the local wall-panel joint, with short stroke and simple construction. It can work in conjunction with existing connection box and sleeve grouting parts, which is different from the traditional prestressed system that runs through the entire wall height.

[0032] (3) Adjustability and easy maintenance: With the reserved inspection holes and exposed ends, the predetermined axial compression level can be easily detected and restored during the service period and after the earthquake, making up for the defects of the existing prestressed system that is difficult to maintain and cannot be compensated for the gradual loss of prestress.

[0033] (4) Performance can be graded and differentiated: Different target additional normal pressures can be set for different floors, different wall sections or different functional areas in the same project. This allows for a zoned design that optimizes the shear resistance of the joints, which helps control the location of failure and the distribution of energy consumption.

[0034] (5) Compatible with design formulas based on fiber model / shear friction theory: This invention can be directly embedded into the interface shear friction design framework based on international recommendations and current standards such as fibMC, and the quantitative relationship of "adjustable axial compression - interface shear bearing capacity" is explicitly incorporated into the node design, which is conducive to engineering promotion. Attached Figure Description

[0035] To more clearly illustrate the technical solution of the present invention, the present invention will be further described below with reference to the accompanying drawings. The drawings are merely illustrative and do not constitute a limitation on the scope of protection of the present invention.

[0036] Figure 1This is a schematic diagram of the overall structure of the prefabricated wall-panel joint shear connection system of the present invention. In the figure: 1-Precast shear wall panel; 2-Precast floor slab or composite slab; 3-Wall-panel joint interface; 4-Connecting box; 5-Grouting sleeve; 6-Vertical duct (metal corrugated pipe); 7-Upper bearing steel plate; 8-Lower bearing steel plate; 9-High-strength prestressed tie rod; 10-Anchor or end plate; 11-Nut; 12-Disc spring assembly; 13-Inspection hole or inspection groove.

[0037] Figure 2 This is a schematic cross-sectional view of the locally vertically adjustable axial pressure device of the present invention along the vertical channel. In the figure, the vertical channel (6), the upper pressure plate (7), the lower pressure plate (8), the high-strength prestressed tie rod (9), the anchor (10), the nut (11), the disc spring assembly (12), the inspection hole (13), and their relative positional relationship with the wall-panel joint interface (3) are shown.

[0038] Figure 3 This is a schematic diagram of the series and parallel combination of disc spring assemblies. In the figure: 121-series disc spring unit; 122-parallel disc spring unit; 123-spacer and positioning shim; disc spring assemblies (12) with specific stiffness-stroke characteristics are formed through different combination forms.

[0039] Figure 4 This is a planar schematic diagram of the adjustable axial pressure device of the present invention working in conjunction with the connecting box / grouting sleeve. In the figure: 4-connecting box; 5-grouting sleeve; 14-longitudinal steel bar or pin in the joint; 15-interface shear groove or roughened surface; vertical duct (6) and its planar relative position with the connecting parts (4, 5) and the interface shear bearing path.

[0040] Figure 5 This is a schematic diagram of the adjustable axial compression device arranged in layers in a multi-story shear wall structure according to the present invention. In the figure: 16-upper floor shear wall; 17-lower floor shear wall; 18-wall-panel joint interface of different floors; 19-vertical adjustable axial compression device with different prestress levels and disc spring combinations; indicating that different numbers and parameters of vertical devices can be set as needed for different floors and different wall sections. Detailed Implementation

[0041] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Those skilled in the art should understand that various equivalent substitutions or modifications can be made to the following embodiments without departing from the spirit and essence of the present invention, and all such substitutions or modifications should fall within the protection scope of the present invention.

[0042] Example 1: Adjustable axial compression structure for wall-panel joints with a single vertical tie rod

[0043] 1. Structural Layout

[0044] like Figure 1 and Figure 2 As shown, at the joint between a typical precast shear wall and a precast composite floor slab, a set of locally adjustable vertical axial compression devices is installed. Specifically, it includes: a precast shear wall panel 1, starting from the foundation or the lower floor slab, whose top surface is connected to the bottom surface of the precast composite floor slab 2 of the same floor through a wall-panel joint interface 3; a connecting box 4 and a grouting sleeve 5 are installed between the top of the wall panel 1 and the end of the composite floor slab 2, so that the reinforcing bars extending from the lower wall panel are connected to the reinforcing bars of the upper floor slab through grouting in the sleeve; a vertical channel 6 is arranged vertically along the side adjacent to the connecting box 4, within a range of 0.3 times the wall thickness from the edge of the wall panel, and this channel is formed by pre-embedded metal corrugated pipes, penetrating from the top surface of the composite floor slab 2 to a certain depth inside the wall panel 1; an upper bearing steel plate 7 and a lower bearing steel plate 8 are pre-embedded at the upper and lower ends of the channel 6, respectively, and the bearing steel plates are integrally fixed to the surrounding concrete through anchoring steel bars and shear keys.

[0045] 2. Arrangement of high-strength prestressed tie rods and disc spring assemblies

[0046] A high-strength prestressed tie rod 9 is inserted into the vertical duct 6. The material can be precision-rolled threaded steel bar or high-strength alloy steel tie rod, and its diameter is determined by calculation. The upper end of the tie rod 9 extends out of the upper bearing steel plate 7, and one end is connected to an anchor or end plate 10, with a certain length of thread exposed for tightening by the nut 11; the lower end can also be equipped with an anchor 10 and a nut 11, or a fixed-end anchoring method can be used. A disc spring assembly 12 is arranged between the upper nut 11 and the upper bearing steel plate 7. The inner and outer diameters, thicknesses, and materials of the disc springs are selected according to the axial force and stiffness requirements. Preferably, the disc spring assembly adopts a combination of multiple disc springs connected in parallel and then in series, so that it has sufficient axial travel, while maintaining a smooth force-displacement curve within the expected displacement range. On the outside of the wall panel 1 or floor slab 2, a maintenance hole 13 is reserved corresponding to the end of the tie rod. The maintenance hole is closed by a removable cover plate, and the internal space meets the needs of wrench operation and stress testing equipment installation.

[0047] 3. Construction Steps

[0048] (1) Factory prefabrication stage:

[0049] In the precast shear wall panel 1 formwork, the lower bearing steel plate 8 is pre-embedded at the designed position and welded or tied to the main reinforcement of the wall with short steel bars. The surface of the bearing steel plate is provided with concave-convex or shear keys to enhance the anchorage. The metal corrugated pipe is fixed to the formwork at the axial position of the vertical channel 6 and connected to the center hole of the lower bearing steel plate 8 so that a continuous channel is formed after the concrete is poured. The wall panel concrete is poured, vibrated to compact and cured. In the precast composite floor slab 2 formwork, the upper bearing steel plate 7 is pre-embedded at the corresponding position and connected to the composite layer reinforcement mesh. At the same time, the upper section of the corrugated pipe of the channel is pre-embedded so that the two sections of corrugated pipe form a through channel 6 when they are stacked and installed on site. Conventional prefabricated connectors such as the connecting box 4 and the grouting sleeve 5 are pre-embedded according to conventional processes.

[0050] (2) On-site installation stage:

[0051] Hoist and temporarily fix the precast shear wall panel 1, and adjust its verticality and position; hoist the precast composite floor slab 2, so that its end falls on the predetermined position on the top of the wall panel 1, ensuring that the gap of the wall-panel splice interface 3 is uniform and the upper and lower sections of the duct 6 are aligned; complete the cleaning and grouting work of the connecting box 4 and the grouting sleeve 5, and the subsequent tensioning operation can be carried out after the grouting material reaches the specified strength; insert the high-strength prestressed tie rod 9 from top to bottom into the vertical duct 6, so that its lower end is aligned with the anchor hole of the lower bearing steel plate 8 and anchored; put the disc spring group 12, washer and nut 11 into the upper end of the tie rod 9 in sequence, and insert a wrench through the inspection hole 13 to tighten the nut 11 according to the design requirements, so that the disc spring group is compressed to the design compression amount.

[0052] (3) Axial pressure setting and testing:

[0053] Use a torque wrench to tighten to the predetermined torque. By tightening nut 11 and combining the thread parameters of the tie rod with the coefficient of friction, the initial axial force can be calculated. Alternatively, apply tension to the tie rod 9 using a jack to the design value, then lock it with nut 11, unload the jack, and record the compression of the disc spring assembly; verify the compression displacement and corresponding axial force of the disc spring assembly 12 through the disc spring-force-displacement calibration curve to ensure the established additional normal pressure. Meets design requirements.

[0054] 4. Working mechanism and force analysis

[0055] Under normal use and seismic loading: At the wall-panel joint interface 3, under the combined action of vertical load and the axial force provided by the prestressed tie rod 9, the normal pressure at the interface is: The shear bearing capacity of the wall-panel interface is calculated according to the aforementioned formula:

[0056]

[0057] in The steel bars in the connecting box 4, the steel bars in the grouting sleeve 5, the interface shear groove 15, and the pin 14 provide the necessary support. When the seismic action causes cracking and relative rotation at the wall-panel joint, the bearing steel plates 7 and 8 at the upper and lower ends of the vertical duct 6 will experience relative displacement. The disc spring assembly 12 is further compressed or rebounded; within the stroke range of the disc spring assembly, the axial force remains within a controllable range as the displacement changes, i.e. The pressure should not be lower than the design limit, so as to ensure that the interface still maintains a high friction and energy dissipation capacity after the crack develops; after the earthquake, if the disc spring undergoes plastic deformation or the prestress of the tie rod decreases significantly, the nut 11 can be tightened again through the inspection hole 13 or the disc spring assembly 12 can be replaced to restore the interface normal pressure to the design value.

[0058] 5. Advantages of this embodiment

[0059] The single tie rod has a simple structure and the construction process is similar to that of conventional prestressing, making it easy to promote in engineering practice. It can add a local "adjustable axial compression" function without significantly changing the original prefabricated node connection form (connection box, sleeve grouting, etc.). It can significantly improve the shear resistance and ductility of the wall-panel joint without destroying the vertical force path of the overall shear wall.

[0060] Example 2: Multi-bracing rod and multi-floor graded adjustable axial compression arrangement

[0061] 1. Construction of multi-link joint

[0062] like Figure 4 As shown, within the same wall-panel joint area, two or more vertical ducts 6 and corresponding high-strength prestressed tie rods 9 can be arranged along the wall thickness direction or the joint length direction. Along the joint length direction, a set of vertically adjustable axial compression devices is arranged every 0.6 to 1.2 m to make the interface normal pressure distribution more uniform. Along the wall thickness direction, vertical ducts 6 are arranged near the tension side and the compression side respectively. By setting disc spring groups 12 with different prestress levels or different stiffnesses, the asymmetric stiffness and energy dissipation distribution of the joint under bending action can be controlled.

[0063] 2. Multi-level hierarchical design

[0064] like Figure 5 As shown, in multi-story prefabricated shear wall structures: for the lower floors, which bear greater seismic shear and axial forces, more or higher-level vertical adjustable axial compression devices 19 can be arranged at the wall-panel joint interface 18 to ensure that... The height should be higher to improve the shear resistance and energy dissipation capacity of the lower interface; for the upper floors, the height can be appropriately reduced. Alternatively, the number of devices can be reduced to guide plastic energy dissipation to be mainly concentrated at predetermined floors or nodes during strong earthquakes, realizing the design concept of "ductile floors" or "ductile nodes". Different floors can use different combinations of disc spring groups to form different axial force-displacement characteristics to match the floor displacement angle curve and the performance requirements during the main shock-aftershock process.

[0065] 3. Design Example

[0066] Assuming the target shear bearing capacity of the wall-panel joint on a certain floor is... The concrete reference shear capacity has been obtained through the connection box and reinforcement configuration. The shear bearing capacity of the pin action The overall structural analysis revealed that the normal pressure at this interface was provided by dead load and live load. Take the interfacial friction coefficient The required additional normal pressure is:

[0067]

[0068] If two vertical tie rods are arranged along the length of the joint, the design value of the additional axial force provided by each tie rod is approximately (The size can be appropriately increased after considering the safety factor and potential losses). Based on this, select the appropriate tie rod diameter and disc spring assembly parameters.

[0069] Example 3: Post-earthquake inspection and readjustment methods

[0070] 1. Post-earthquake inspection process

[0071] After a moderate or strong earthquake, the following checks are performed on the wall-panel joints equipped with the adjustable axial pressure device of this invention: Visual inspection and necessary non-destructive testing are conducted to determine whether there are obvious damages such as through cracks or peeling at the wall-panel joint interface 3; the cover of the inspection hole 13 is opened, and the current tightening torque of the end nut 11 is measured using a torque wrench, or the actual axial force of the tie rod 9 is measured using a stress gauge; the measured axial force value is compared with the original design axial force. In comparison, when the axial force drops below the design allowable value (e.g., 20%), it is determined that readjustment is required.

[0072] 2. Readjustment and Repair

[0073] If the disc spring assembly 12 does not show obvious plastic deformation or damage, the nut 11 can be tightened again without removing the component to restore the disc spring to the design compression. If cracks, permanent deformation, or severe corrosion are found in the disc spring assembly, the damaged disc spring can be removed, and a new disc spring assembly 12 can be replaced through the inspection hole 13, and then tightened according to the design requirements. In individual cases where the tie rod 9 shows buckling or severe corrosion, the tie rod can be pulled out and replaced by removing the end anchor 10 after unloading the local load at the corresponding node. Since the tie rod only crosses a local joint and is relatively short, the replacement is relatively convenient.

[0074] 3. Long-term performance and maintenance strategy

[0075] During the building's service life, the adjustable axial compression devices of key floors and wall sections can be inspected and retested according to a predetermined cycle (e.g., 3-5 years). The axial force test results of the nodes can be combined with the structural monitoring system (e.g., acceleration and displacement monitoring) to assess the performance degradation of the nodes under earthquakes or long-term environmental effects, and to appropriately increase or decrease the local axial compression level as needed. For important buildings, strain gauges or fiber optic sensors can be installed on the key adjustable axial compression devices to monitor the stress of the tie rods online, further improving safety and maintainability.

[0076] The above embodiments detail the structural design, construction method, design concept, and maintenance strategy of the present invention, demonstrating its comprehensive advantages in improving the shear bearing capacity, energy dissipation capacity, and maintainability of prefabricated wall-panel joints. After reading this specification, those skilled in the art can make appropriate adjustments to the number of tie rods, their arrangement, the type of disc spring assembly, and the prestress level according to specific engineering needs; all of these adjustments fall within the scope of protection of this invention.

Claims

1. A prefabricated wall-panel joint shear-resistant connection system, comprising a prefabricated shear wall panel (1), a prefabricated floor slab or composite slab (2), and a wall-panel joint interface (3) disposed between the two, characterized in that: At least one set of locally vertically adjustable axial compression devices is provided near the wall-panel joint interface (3). The device includes: (1) a pre-embedded metal corrugated pipe or sleeve arranged along a predetermined vertical channel (6); (2) an upper bearing steel plate (7) and a lower bearing steel plate (8) located at the upper and lower ends of the vertical channel (6) and tightly anchored to the concrete; (3) a high-strength prestressed tie rod or short bundle (9) that passes through the vertical channel (6), passes through the upper bearing steel plate (7) and the lower bearing steel plate (8) at both ends in sequence, and is anchored by an anchor or end plate; (4) a nut set at at least one end. (11) A disc spring assembly (12) between the corresponding bearing steel plate, wherein the disc spring assembly (12) applies an adjustable vertical axial pressure to the bearing steel plate when compressed; the vertical channel (6) and the bearing steel plate are arranged in the vicinity of the connecting box or grouting sleeve connector (4, 5) near the wall-panel joint interface (3), so that the vertical axial force generated by the high-strength prestressed tie rod (9) is directly applied to the concrete on both sides of the wall-panel joint interface (3) through the bearing steel plate, thereby providing an adjustable normal pressure to the joint interface to improve the interface shear friction bearing capacity and energy dissipation capacity.

2. The system according to claim 1, characterized in that: The vertical duct (6) extends from the top of the precast shear wall panel (1) to the lower part of the precast floor slab or composite slab (2), or from the top of the floor slab (2) to the lower part of the wall panel (1). The axis of the duct is located within 0.2 to 1.0 times the thickness of the wall panel inside the wall-panel joint interface (3), and is arranged perpendicular to the length direction of the wall-panel joint.

3. The system according to claim 1 or 2, characterized in that: The disc spring assembly (12) is composed of multiple disc springs connected in series and parallel. By adjusting the number of disc springs connected in series and parallel, the initial compression and the limit stroke, the disc spring assembly can provide a basically constant or predetermined stiffness-displacement relationship within the expected displacement range to compensate for the axial pressure loss caused by cracking of wall-panel joints, concrete shrinkage and creep and steel relaxation.

4. The system according to any one of the preceding claims, characterized in that: A detachable and closed inspection groove or inspection hole (13) is reserved on the outer side of the end of the high-strength prestressed tie rod (9). The inspection groove or inspection hole allows tools such as wrenches, torque wrenches, and stress gauges to enter, so as to realize the detection of tie rod stress, the status inspection of disc spring assembly (12), and re-tightening or replacement during service.

5. The system according to any one of the preceding claims, characterized in that: The wall-panel joint interface (3) is provided with longitudinal steel bars or shear pins connected by connecting boxes (4) or grouting sleeves (5). The locally vertical adjustable axial pressure device is arranged adjacent to the connecting boxes (4) or grouting sleeves (5) in the plane along the length direction of the wall-panel joint, so that the shear resistance of the wall-panel interface is jointly borne by shear friction and pin action. Furthermore, the interface friction bearing capacity and pin bearing capacity can be distributed according to the target ratio by adjusting the normal pressure provided by the adjustable axial pressure device.

6. The system according to any one of the preceding claims, characterized in that: In the same prefabricated building, the number of locally vertically adjustable axial compression devices, the diameter of tie rods, the prestress level and the combination form of disc spring groups (12) set at the wall-panel joint interface (3) of different floors or different wall sections can be determined according to the design to achieve graded and differentiated design of shear resistance performance of different floors or different wall sections.

7. A method for setting axial pressure during the construction phase of the system as described in any one of claims 1-6, characterized in that, include: (1) Pre-embed vertical ducts (6) and pressure-bearing steel plates (7, 8) in the factory prefabrication stage of prefabricated shear wall panels (1) and prefabricated floor slabs (2), and reserve inspection holes (13); (2) hoist and temporarily position the wall panels (1) and floor slabs (2) on site, and complete the grouting of the connection box or grouting sleeve (4, 5); (3) pass the high-strength prestressed tie rod (9) through the vertical duct (6), and install the anchor and disc spring assembly (12) and nut (11); (4) use tensioning equipment or torque wrench to control the tension force or tightening torque according to the design, so that the disc spring assembly (12) reaches the design compression amount, thereby establishing the target normal pressure at the wall-panel joint interface (3).

8. A method for service and post-earthquake axial compression readjustment based on the system according to any one of claims 1-6, characterized in that: Through the inspection hole (13), use a stress gauge, torque wrench or other indirect stress measurement methods to periodically or after an earthquake to re-measure the actual axial force of the high-strength prestressed tie rod (9); when the axial force is detected to have dropped more than the predetermined threshold from the design value, loosen or replace the disc spring assembly (12) and tighten the nut (11) again to restore the axial force to the design range.

9. The system according to any one of claims 1-6, characterized in that: Multiple high-strength prestressed tie rods (9) and corresponding vertical ducts (6) are arranged along the wall thickness direction or the joint length direction within the same wall-panel joint node. Each tie rod can be set with different initial prestress or disc spring group (12) stiffness to control the rotational stiffness and energy consumption distribution of the node in different directions or positions.

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