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CN-122013894-A - Assembled wall-board piece shear connection system

CN122013894ACN 122013894 ACN122013894 ACN 122013894ACN-122013894-A

Abstract

The invention discloses a shear connection system for assembled wall-board joints, and belongs to the technical field of assembled concrete structures. The system is characterized in that a local vertical duct penetrating through a wall-plate interface is arranged near a horizontal joint of a precast shear wall and a precast floor slab or a superimposed sheet, steel bearing plates are arranged at the upper end and the lower end of the duct, a high-strength prestress pull rod is penetrated, and two ends of the steel bearing plates are locked through an anchor and a nut to form an adjustable axial pressure device with stroke compensation capability. The axial compression device is arranged near the connecting box or the sleeve grouting connecting piece, so that the shearing friction bearing capacity and the energy consumption capacity are improved. And setting target axle pressure by tightening nuts in the construction stage, and compensating the prestress loss and the axle pressure attenuation caused by interface cracking. The invention converts the axial pressure ratio formed passively by the integral structure into the local normal pressure which can be designed on the node layer surface, is suitable for the differential design of the shear resistance of interfaces of different wall sections, and is different from the traditional prestress system crossing the whole wall.

Inventors

  • HUANG YUAN
  • HUANG XIANGYU

Assignees

  • 湖南大学

Dates

Publication Date
20260512
Application Date
20260309

Claims (9)

  1. 1. A shear connection system for assembled wall-plate joints comprises a prefabricated shear wallboard (1), a prefabricated floor slab or laminated slab (2) and a wall-plate joint interface (3) arranged between the prefabricated shear wallboard and the prefabricated floor slab or laminated slab, and is characterized in that at least one group of local vertical adjustable axial compression devices are arranged near the wall-plate joint interface (3), each device comprises (1) embedded metal corrugated pipes or sleeves arranged along a preset vertical duct (6), (2) upper bearing steel plates (7) and lower bearing steel plates (8) which are positioned at the upper end and the lower end of the vertical duct (6) and tightly anchored with concrete, (3) high-strength pre-stressed pull rods or short bundles (9) which penetrate through the vertical duct (6) and penetrate through the upper bearing steel plates (7) and the lower bearing steel plates (8) in sequence and are anchored through an end plate or end plate, (4) a disc spring group (12) arranged between at least one end nut (11) and a corresponding bearing steel plate, when compressed, the disc spring group (12) applies adjustable axial compression force to the bearing steel plates, the vertical duct (6) and the pull rods (8) are directly connected with the two sides of the wall-plate joint interface (3) through the high-strength pre-stressed pull rods or short bundles (9), thereby providing adjustable normal pressure for the joint interface so as to improve the shearing friction bearing capacity and the energy consumption capacity of the interface.
  2. 2. The system of claim 1, wherein the vertical channels (6) penetrate from the top of the prefabricated shear wall board (1) to the lower part of the prefabricated floor slab or the laminated slab (2), or penetrate from the top of the floor slab (2) to the lower part of the wall board (1), and the axes of the channels are positioned in the thickness range of 0.2-1.0 times of the wall board inside the wall-board joint interface (3) and are arranged vertically to the length direction of the wall-board joint.
  3. 3. The system of claim 1 or 2, wherein the disc spring stack (12) is formed by combining a plurality of disc springs in series-parallel, and the disc spring stack is configured to provide a substantially constant or varying axial pressure-displacement relationship with a predetermined stiffness over a desired displacement range by adjusting the number of disc springs in series-parallel, the initial compression and the limit travel to compensate for wall-plate joint cracking, concrete shrinkage creep and axial pressure loss due to steel relaxation.
  4. 4. The system according to any one of the preceding claims, characterized in that a detachable and closed access groove or access hole (13) is reserved at the outer side of the end part of the high-strength prestress pull rod (9), and the access groove or access hole is used for allowing tools such as a spanner, a torque spanner, a stress meter and the like to enter so as to realize the detection of the stress of the pull rod in the service period, the state inspection of the disc spring group (12) and the screwing or the replacement again.
  5. 5. The system according to any one of the preceding claims, characterized in that a longitudinal steel bar or a shear pin connected with a connecting box (4) or a grouting sleeve (5) is arranged in the wall-plate joint interface (3), the local vertical adjustable axial pressure device is arranged adjacently to the connecting box (4) or the grouting sleeve (5) in a plane along the length direction of the wall-plate joint, so that shearing resistance of the wall-plate interface is commonly born by shearing friction and pin action, and interface friction bearing force and pin bearing force can be distributed according to a target proportion by adjusting normal pressure provided by the adjustable axial pressure device.
  6. 6. The system according to any one of the preceding claims, characterized in that in the same building, the number of local vertical adjustable axial pressure devices, the diameter of pull rods, the prestress level and the combination form of belleville spring groups (12) arranged at the wall-plate joint interfaces (3) of different floors or different wall sections can be respectively determined according to designs, so as to realize the grading and differential design of the shearing resistance of the interfaces of different floors or different wall sections.
  7. 7. A construction stage axial pressure setting method of a system according to any one of claims 1-6 is characterized by comprising the steps of (1) embedding vertical channels (6) and pressure-bearing steel plates (7, 8) in a factory prefabrication stage of a prefabrication shear wallboard (1) and a prefabrication floor slab (2) and reserving overhaul holes (13), (2) hoisting and temporarily positioning the wallboard (1) and the floor slab (2) on site to finish grouting of a connecting box or grouting sleeve (4, 5), (3) penetrating a high-strength prestress pull rod (9) through the vertical channels (6) and installing an anchor and a disc spring set (12) and a nut (11), and (4) controlling the tension force or the tightening moment according to design by adopting tension equipment or a moment wrench to enable the disc spring set (12) to reach a design compression amount so as to establish a target normal pressure at a wall-plate joint interface (3).
  8. 8. A service and post-earthquake axle pressure readjustment method based on the system according to any one of claims 1-6, characterized in that the actual axle force of the high-strength pre-stress pull rod (9) is measured periodically or post-earthquake by adopting a stress meter, a moment wrench or other stress indirect measurement means through the manhole (13), and when the axle force is detected to be reduced more than a preset threshold value, the disc spring group (12) is loosened or replaced and the nut (11) is screwed down again, so that the axle force is restored to the design range.
  9. 9. The system according to any one of claims 1-6, wherein a plurality of high-strength pre-stressed tie rods (9) and corresponding vertical channels (6) are arranged along the wall thickness direction or the joint length direction within the same wall-plate joint range, and each tie rod can be provided with different initial pre-stress or stiffness of a belleville spring group (12) so as to control the rotational stiffness and energy consumption distribution of the joint in different directions or at different positions.

Description

Assembled wall-board piece shear connection system Technical Field The invention relates to the technical field of assembled concrete structures, in particular to a shear connection system for horizontal joints between a prefabricated shear wall and a prefabricated floor slab or a superimposed sheet, and especially relates to a shear connection system for assembled wall-plate joints, which is used for regulating and controlling normal pressure of an interface and improving shear friction bearing capacity and energy consumption capacity by locally adding an adjustable vertical prestressing device to a wall-plate joint. Background The assembled shear wall structure realizes integral connection through components such as factory prefabricated wallboards, floors and the like on site through wet joints, sleeve grouting, connecting pieces and the like, and has the advantages of high industrialization degree, high construction speed and the like. Vertical joints between wallboard and horizontal joints between wallboard and floor are critical sites determining structural integrity and seismic performance. In the prior art, the connecting mode of the vertical joints and the horizontal joints of the prefabricated shear wall mainly comprises grouting connection of a reinforcing steel sleeve, slurry anchor connection, reinforcement anchoring of a cast-in-situ lamination layer, setting of shear keys or tooth grooves, local steel plate connection and the like. For example, a prefabricated shear wall vertical joint connection structure is disclosed in the literature, reliable connection between wallboards is achieved through a reinforcing steel sleeve and post-cast concrete, and bearing capacity and ductility are improved. The prior art also uses prestress bars to penetrate through the height of the shear wall so as to improve the overall rigidity and self-resetting capability. For the wall-plate joint, the current specifications and researches mostly adopt that the integral connection of the joints is realized through the overlapping layers of the floor slabs, the joint bars and the sleeve grouting, the shearing resistance and the sliding resistance are realized through interface roughening and the cooperation of the shearing tooth grooves and the vertical steel bars, and in a few self-resetting systems, the integral stress of the wall-plate joints along with the wall feet is realized through the vertical prestressed tendons penetrating through the whole wall height. Numerous studies and design specifications indicate that the axial compression ratio of concrete members has a significant impact on shear wall shear capacity, deformation capacity and joint slip resistance. For a prefabricated interface designed by adopting a shear friction theory, the shear bearing capacity of the prefabricated interface can be generally expressed as: Wherein: Designing a value for the shear bearing capacity of the interface; the concrete standard shear bearing capacity is used without considering the additional normal pressure; Is the interface friction coefficient; Designing a value for normal pressure acting on the interface; Shear load bearing capacity to be contributed by the cross-interface rebar or pin. In existing fabricated shear wall structures, the normal pressure acting on the wall-panel jointsThe structure is mainly determined by the integral stress state (constant load, live load, upper wall body and floor slab force transmission path and the like), and can only be indirectly influenced by changing the integral arrangement of the structure, the size of a member or the load combination and the like, so that the fine and adjustable design of the normal pressure of a single joint interface is difficult to realize on the node structure level. The method has the advantages that for different floors and different wall sections, interface axial pressure levels are difficult to be configured in a targeted mode according to the characteristics of earthquake response and the destruction mode, and the axial pressure reduction caused by shrinkage creep of concrete, looseness of steel, crack development and the like in long-term use cannot be effectively compensated, so that the long-term shearing bearing capacity and the energy consumption performance are affected. In recent years, scholars at home and abroad propose various systems for improving the earthquake resistance of an assembled structure by utilizing a prestress and energy dissipation device. For example, the self-resetting precast shear wall is realized by adopting vertical prestressed tendons penetrating through the whole wall, or a belleville spring device is arranged at the beam end of the assembled frame, so that the node ductility and the energy consumption capability are improved. Related researches show that the disc spring group has higher energy dissipation capacity and controllable rigidity-stroke characteristic, is suitable for being combined with a prestress s