Low-prestress double-slope friction variable-stiffness self-resetting concrete beam-column joint device

Abstract

The utility model discloses a low-prestress double-slope friction variable-stiffness self-resetting concrete beam column joint device which comprises a precast concrete column, a precast concrete beam located on one side of the precast concrete column and a variable-stiffness energy dissipater connecting the precast concrete column and the precast concrete beam into a whole. The variable stiffness energy dissipater comprises a middle slope surface steel plate with a fluctuating surface, an outer slope surface steel plate with a fluctuating surface and an inner plane steel plate connected to the prefabricated concrete beam. The anti-seismic structure is provided with a three-section type multi-section flag-shaped hysteretic curve, so that the anti-seismic requirement of the structure under the intensity of small earthquakes and medium earthquakes can be met, and the energy under the action of large earthquakes can be better consumed; the interlayer angular displacement, the floor acceleration and the like of the structure are obviously reduced under the conditions of small earthquakes, medium earthquakes and large earthquakes; the connecting structure has the advantages of small residual deformation after an earthquake, light structural damage and the like, and meanwhile, obvious plastic deformation of main structural members such as precast concrete beam columns and the like is avoided.

Description

TECHNICAL FIELD

[0001] The utility model belongs to building energy consumption component field relates to low prestress double-slope surface friction variable rigidity self-resetting concrete beam column joint device. BACKGROUND

[0002] Earthquake seriously affects the survival and development of human beings, the time, place and intensity of earthquake occurrence have great randomness and unpredictability, people cannot prevent the occurrence of earthquake, only rely on own technical means to prevent earthquake and reduce various losses caused by it. According to the traditional method of strengthening the strength, rigidity, ductility and other properties of structure to resist earthquake action, although it has certain reliability in avoiding the damage of building and even the collapse to cause personnel casualty, but in moderate intensity earthquake or strong earthquake, it cannot effectively control the economic loss caused by earthquake, after most strong earthquakes, the structure is damaged and is not easy to repair, only can be demolished and reconstructed. In recent years, arranging damping energy absorber in structure, through friction, bending, elastic-plastic hysteretic deformation and other energy dissipation modes can reasonably and effectively resist earthquake, and the self-resetting prestressed concrete frame structure not only can protect the life and property of personnel during the occurrence of earthquake, but also has small residual displacement after earthquake, which is beneficial to repair, gradually develops into a new type of frame structure based on performance-based earthquake engineering research. The friction type self-resetting prestressed concrete frame structure is one of recoverable function anti-seismic structure system, the prefabricated beam and column are assembled together through horizontally arranged unbonded prestressed steel strand, the friction energy absorber (composed of inner and outer friction steel plate, friction plate and friction bolt etc.) is arranged at the beam column joint, the rigid connection at the joint is changed into ductile connection, so that the gap at the joint contact surface can open and close. The structure not only maintains the advantages of traditional cast-in-place frame, but also has seismic performance and recovery performance. The realization of structure self-resetting lies in the design of joint, the double-slope surface friction variable rigidity semi-self-resetting concrete beam column joint device is a joint device that can make the structure deformation recover after earthquake, has the advantages of fabricated joint and good ability to cope with earthquake. The realization of structure energy dissipation lies in the design of energy absorber, at present, the friction force of friction energy absorber does not change and the rigidity is zero after starting, cannot play the role of having different rigidity under different earthquake magnitude, leads to small energy dissipation, cannot achieve the expected effect, and in the design of existing self-resetting prestressed concrete frame, complete reset of joint is emphasized, high tension of prestressed tendon is required, but high prestress will lead to too low energy dissipation ratio, so that the structure consumes limited energy during earthquake, the remaining energy is consumed through beam and column damage, causes the structure to be difficult to repair or impossible to repair. In addition, the rigidity of friction type self-resetting prestressed concrete frame is low under strong earthquake, easy to cause obvious high-order modal effect of frame structure, and the structure deformation is easy to concentrate, the local floor displacement angle increases, and the post-earthquake reset ability of structure is also affected.

[0003] Therefore, a low-prestressed double-slope frictional variable stiffness self-centering concrete beam-column joint device is developed by using multi-stage friction and variable stiffness, which effectively improves the stiffness and energy dissipation capacity of the self-centering prestressed concrete frame after the joint is opened. Utility model content

[0004] The utility model discloses to overcome the problem of the energy dissipation device in prior art that energy consumption is limited during the earthquake process, and the low stiffness of the friction type self-centering prestressed concrete frame under the strong earthquake, and provide a low-prestressed double-slope frictional variable stiffness self-centering concrete beam-column joint device, which can effectively resist and consume the energy under the strong earthquake, thereby reducing the seismic response and damage of the structure, effectively ensuring the safety performance of the structure under the earthquake action, and avoiding the obvious plastic deformation of the main structure component such as the prefabricated beam column.

[0005] Technical scheme: in order to realize the above-mentioned purpose, the utility model adopts the technical scheme that:

[0006] A low-prestressed double-slope frictional variable stiffness self-centering concrete beam-column joint device, comprising a prefabricated concrete column, a prefabricated concrete beam and a variable stiffness energy dissipation device, the prefabricated concrete beam is arranged on the side of the prefabricated concrete column through the variable stiffness energy dissipation device, the variable stiffness energy dissipation device comprises a friction end plate, a friction connecting plate, a friction fixing plate, an outer slope steel plate, a middle slope steel plate, a brake pad, an inner plane steel plate and a friction type high-strength bolt, the friction fixing plate is arranged on the side of the prefabricated concrete column, the two friction fixing plates are connected into one through the friction connecting plate, the middle slope steel plate is connected to the friction connecting plate to form a whole, and the middle slope steel plate is connected to the prefabricated concrete column into a whole through the friction bolt hole reserved in the friction fixing plate by the pressure type high-strength bolt, two inner plane steel plates are symmetrically arranged on the top and bottom of the prefabricated concrete beam, the two inner plane steel plates are connected into one through the friction end plate, the brake pad is arranged in the partial area between the inner plane steel plate and the outer slope steel plate, the inner plane steel plate and the outer slope steel plate are connected into a whole with the prefabricated concrete beam through the friction type high-strength bolt, and the middle slope steel plate is arranged in the remaining area between the outer slope steel plate and the inner plane steel plate.

[0007] Preferably, the friction type high-strength bolt is provided with a disc spring arranged on the outer side of the outer slope steel plate.

[0008] Preferably, the disc spring is arranged at the end of the friction type high-strength bolt and the pressure type high-strength bolt.

[0009] Preferably, the first friction bolt hole reserved on the prefabricated concrete beam, the second friction bolt hole on the inner plane steel plate and the fourth friction bolt hole on the outer slope steel plate have the same hole diameter, and the hole diameter is smaller than that of the third friction bolt hole on the middle slope steel plate.

[0010] Preferably, the friction type high-strength bolt is connected and fixed with the precast concrete beam after passing through the fifth friction bolt hole, the fourth friction bolt hole, the third friction bolt hole, the second friction bolt hole and the first friction bolt hole.

[0011] Preferably, the opposite sides of the outer slope steel plate and the middle slope steel plate are provided with undulating surfaces, and the undulating surfaces of the two are interlaced and embedded.

[0012] Preferably, the transverse prestressed tendons are arranged in the precast concrete column and the precast concrete beam.

[0013] Preferably, the brake pad is embedded in the inner plane steel plate by grooving, and the brake pad is integrally formed with the inner plane steel plate.

[0014] Preferably, the friction fixing plate is fixed on the side of the precast concrete column through the pressure type high-strength bolt.

[0015] Preferably, the two slopes of the outer slope steel plate and the middle slope steel plate are the same.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] 1. The node device of the utility model sets undulating surfaces and brake pads to realize multi-stage energy dissipation and variable rigidity, and low prestressed tendons are arranged in the upper and lower parts of the beam to realize self-resetting, and the application of low prestress not only helps the rapid installation of the structure, but also improves the energy dissipation capacity of the structure. The node device can effectively solve the bottleneck problem in the further popularization and application of the self-resetting prestressed concrete frame. Compared with the traditional energy dissipation device, the variable rigidity energy dissipation device has adjustable and controllable rigidity, and the rigidity is not zero after the energy dissipation device is started, and the energy dissipation capacity is greatly improved. The variable rigidity energy dissipation device is divided into three stages after starting, and has different rigidity under different seismic levels in each stage, effectively consuming and resisting the energy under the action of small earthquakes, medium earthquakes and large earthquakes. The self-resetting structure can realize automatic resetting of the structure after the action of the earthquake and reduce the damage of the beam column joint area, has good seismic performance, and has small residual displacement after the earthquake, and can continue to be used after slight repair or even without repair after the earthquake, greatly reducing the repair cost after the earthquake

[0018] 2. The utility model has three-section type "multi-section flag shape" hysteresis curve, not only can satisfy structure under small earthquake, medium earthquake intensity seismic demand, can consume energy under large earthquake better still;Respectively under small earthquake, medium earthquake, large earthquake make structure's interlayer angular displacement and floor acceleration etc. Significantly reduce;The utility model has small residual deformation after the earthquake, light structure damage and other advantages, at the same time, avoid the obvious plastic deformation of the main structure component such as precast concrete beam column. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1This is a schematic diagram of the structure of the device of the utility model;

[0020] Figure 2 for Figure 1 1-1 section;

[0021] Figure 3 It is the node rotation mechanism;

[0022] Figure 4 The energy dissipation mechanism of variable stiffness of the open node at the beam-column interface;

[0023] Figure 5 This is the front view of the precast concrete column and opening;

[0024] Figure 6 This is a side view of the precast concrete column and opening;

[0025] Figure 7 This is a schematic diagram of the precast concrete beam and openings;

[0026] Figure 8 This is a schematic diagram of the opening and connection of the inner plane steel plate;

[0027] Figure 9 This is a schematic diagram of the opening and connection of the steel plate on the mid-slope surface;

[0028] Figure 10 This is a schematic diagram of the outer slope steel plate and openings;

[0029] Figure 11 This is a schematic diagram of the brake pad and opening;

[0030] Figure 12 is a schematic diagram of the hysteresis curve;

[0031] Among them are: precast concrete column 1; precast concrete beam 2; friction end plate 3; friction connecting plate 4; friction fixing plate 5; outer slope steel plate 6; middle slope steel plate 7; brake pad 8; inner plane steel plate 9; friction type high-strength bolt 10; pressure-bearing high-strength bolt 11; prestressed tendon 12; prestressed tendon anchor 13; first friction bolt hole 14; second friction bolt hole 15; third friction bolt hole 16; fourth friction bolt hole 17; fifth friction bolt hole 18; sixth friction bolt hole 19; seventh friction bolt hole 20; disc spring 21. DETAILED DESCRIPTION

[0032] The present invention is further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention made by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0033] A low prestress double slope surface friction variable stiffness self-resetting concrete beam-column joint device, as shown in Figures 1-11 The device comprises a prefabricated concrete column 1, a prefabricated concrete beam 2, and a variable stiffness energy dissipation device, wherein the prefabricated concrete beam 2 is arranged on the side of the prefabricated concrete column 1 through the variable stiffness energy dissipation device, the main component of the embodiment comprises the prefabricated concrete column 1 and the prefabricated concrete beam 2, and the connecting component comprises the upper and lower variable stiffness energy dissipation devices of the joint. Under the action of an earthquake, the prestressed tendon 12 in the self-resetting prestressed concrete beam-column joint can provide a self-resetting force to eliminate or reduce the residual deformation of the joint, and the variable stiffness energy dissipation device arranged at the beam-column joint can dissipate a large amount of seismic energy, realize multi-stage activation, variable stiffness after activation, control high-order modal effects through the stiffness after activation, increase the energy dissipation capacity through the variable stiffness, thereby reduce the inter-story drift angle and acceleration of the self-resetting prestressed concrete frame structure, avoid obvious plastic deformation of the main structural components such as the prefabricated concrete beam column, and the seismic force is borne by the prefabricated concrete beam column, the prestressed tendon and the variable stiffness energy dissipation device. The structures of the following parts are described in detail.

[0034] As shown in Figure 1 The self-resetting prestressed concrete frame comprises a prefabricated concrete column 1 and a prefabricated concrete beam 2 as the main component of the joint, and after being assembled into a whole through the connecting components such as the variable stiffness energy dissipation device and the prestressed tendon, the energy dissipation capacity and the recoverable performance of the structure can be effectively improved, and the seismic design of the structure under different seismic capacity requirements is facilitated.

[0035] The variable stiffness energy dissipation device comprises friction end plates 3, friction connecting plates 4, friction fixing plates 5, outer slope steel plates 6, middle slope steel plates 7, brake pads 8, inner plane steel plates 9, and friction type high-strength bolts 10. The friction fixing plates 5 are arranged on the side of the precast concrete column 1, the friction connecting plates 4 connect two friction fixing plates 5 into one, the middle slope steel plates 7 are connected to the friction connecting plates 4 to form an integral whole, and the middle slope steel plates are connected to the precast concrete column 1 by pressure type high-strength bolts 11 passing through the friction bolt holes reserved in the friction fixing plates 5. Two inner plane steel plates 9 are symmetrically arranged on the top and bottom of the precast concrete beam 2, the friction end plates 3 connect the two inner plane steel plates 9 into one, the brake pads 8 are arranged in the partial area between the inner plane steel plates 9 and the outer slope steel plates 6, the inner plane steel plates 9 and the outer slope steel plates 6 are connected to the precast concrete beam 2 by the friction type high-strength bolts 10 to form an integral whole, and the middle slope steel plates 7 are arranged in the remaining area between the outer slope steel plates 6 and the inner plane steel plates 9. The two inner plane steel plates 9 with second friction bolt holes 15 in the variable stiffness energy dissipation device are welded to the friction end plates 3 to form an integral whole, the two middle slope steel plates 7 with friction bolt holes and undulating surfaces are connected by the friction connecting plates 4 to form an integral whole, the friction fixing plates 5 connected to the friction connecting plates 4 are installed with bolts to be embedded in the precast concrete column 1 without being separated, and the inner plane steel plates 9, the middle slope steel plates 7, the outer slope steel plates 6, and the brake pads 8 are connected into one by the friction type high-strength bolts 10 Figure 2 And the variable stiffness energy dissipation device is formed.

[0036] In this embodiment, the node device comprises a precast concrete column 1, a precast concrete beam 2 located on one side of the precast concrete column 1, and two upper and lower variable stiffness energy dissipaters connecting the precast concrete column 1 and the precast concrete beam 2 into one body. The first friction bolt hole 14 reserved on the precast concrete beam 2, the second friction bolt hole 15 on the inner plane steel plate 9, and the fourth friction bolt hole 17 on the outer slope steel plate 6 have the same hole diameter, which is smaller than the hole diameter of the third friction bolt hole 16 on the middle slope steel plate 7. The variable stiffness energy dissipater comprises two friction fixing plates 5 connected on the side of the precast concrete column 1, a friction connecting plate 4 connecting the two friction fixing plates 5 into one body, and two middle slope steel plates 7 connected on the friction connecting plate 4 to form a whole. The friction fixing plate 5 is fixed on the side of the precast concrete column 1 through the pressure type high-strength bolt 11. The middle slope steel plate is connected into a whole with the precast concrete column 1 through the pressure type high-strength bolt 11 passing through the friction bolt hole reserved on the friction fixing plate 5. Two inner plane steel plates 9 are symmetrically arranged on the top and bottom sides of the precast concrete beam 2. The two inner plane steel plates 9 are connected into one body by a friction end plate 3. The brake pad 8 is arranged in the partial area between the inner plane steel plate 9 and the outer slope steel plate 6. In the variable stiffness energy dissipater, the brake pad 8 is embedded in the inner plane steel plate 9 by grooving. The brake pad 8 is kept in one body with the inner plane steel plate 9. The inner plane steel plate 9 and the outer slope steel plate 6 are connected into one whole with the precast concrete beam 2 through the friction type high-strength bolt 10. The middle slope steel plate 7 is arranged in the remaining area between the outer slope steel plate 6 and the inner plane steel plate 9. The disc spring 21 located outside the outer slope steel plate 6 is installed on the friction type high-strength bolt 10. The friction type high-strength bolt 10 is connected and fixed with the precast concrete beam 2 after passing through the fifth friction bolt hole 18, the fourth friction bolt hole 17, the third friction bolt hole 16, the second friction bolt hole 15, and the first friction bolt hole 14. The opposite sides of the outer slope steel plate 6 and the middle slope steel plate 7 are arranged as undulating surfaces, and the undulating surfaces of the two are interlaced and embedded. The precast concrete column 1 and the precast concrete beam 2 are provided with transverse prestressed tendons 12 penetrating through them. The two slopes of the outer slope steel plate 6 and the middle slope steel plate 7 are the same. The first slope of the outer slope steel plate 6 is smaller than the second slope of the outer slope steel plate 6. The first slope of the middle slope steel plate 7 is smaller than the second slope of the middle slope steel plate 7. Low prestress is applied to the prestressed tendons to improve the energy dissipation capacity. The disc spring 21 located outside the outer slope steel plate 6 is installed on the friction type high-strength bolt 10. The disc spring 21 is installed at the end of the friction type high-strength bolt 10 and the pressure type high-strength bolt 11.

[0037] In the design process, low prestress is applied on the prestressed tendon to improve the energy dissipation capacity, the prestressed tendon 12 generates pressure on the prestressed concrete beam 2 and bears the bending moment, and the shear force at the beam end is mainly borne by the higher friction and variable stiffness energy dissipation device between the slope steel plate and the outer slope steel plate generated by the prestressed tendon 12. The secondary starting stiffness and the third starting stiffness of the energy dissipation device can be effectively controlled by adjusting the angle of the undulating surface section, so as to improve the energy dissipation capacity and recovery capacity of the structure under strong earthquakes.

[0038] The node device of the utility model is based on the close integration of "variable stiffness energy dissipation" and "low prestress to achieve expected residual displacement", and the basic principle is that the variable stiffness energy dissipation device realizes two-stage starting and variable stiffness after starting by changing the friction pretightening force, controls high-order modal effect by variable stiffness, and increases energy dissipation capacity by variable friction. Under the action of small earthquakes, the node does not open, the structure is "equivalent to cast-in-place", is in an elastic state, and has sufficient initial stiffness, and resists the action of small earthquakes together with the main body of the structure, so that the structure meets the needs of strength and stability; under the action of medium earthquakes, the beam column rotates and drives the relative sliding between the middle slope steel plate and the inner plane steel plate and the outer slope steel plate, slides to the first undulating surface section, so that the structure has secondary stiffness, generates large damping, the variable stiffness energy dissipation device enters the elastic-plastic state, and the energy dissipation and shock absorption mode is started to reduce the dynamic response of the structure; under the action of large earthquakes, the second undulating surface section is started, the disc spring is continuously compressed, the normal pressure is increased, and then the friction is increased, so that the structure has tertiary stiffness, and the energy dissipation capacity is continuously increased, so as to reduce the inter-story drift angle and acceleration of the self-centering prestressed concrete frame structure, reduce or avoid the inelastic deformation of the structure itself, and finally ensure that the building structure still has strong safety performance under the action of strong earthquakes.

[0039] The utility model discloses a prefabricated concrete beam column node with low prestress and variable stiffness energy dissipation device are combined together to resist the earthquake action together and consume the earthquake energy. The structure contains prefabricated concrete column, prefabricated concrete beam, variable stiffness energy dissipation device. The slope steel plate does not separate from the prefabricated concrete column in the node rotation process. The inner plane steel plate and the middle slope steel plate and the outer slope steel plate generate relative sliding to dissipate the earthquake energy, and the prestressed tendon penetrating through the prefabricated concrete column and the prefabricated concrete beam provides self-centering force to restore the beam column to the position before deformation.

[0040] In the factory, the concrete column and the concrete beam are prefabricated, and the prestressed tendon holes are reserved at the corresponding positions. After the beam and column components are hoisted in place, the prestressed tendons are passed through the holes reserved in the beam and column, and then tensioned. The post-tensioned un-bonded prestressed tendons can be used for device connection in the installation stage, and can also bear the tension and bending moment effect in the use stage. In order to improve the energy dissipation capacity of the node device in the use process and the large reduction of the post-tensioned un-bonded prestressed tendons, a pair of variable stiffness energy dissipation devices are arranged at the upper and lower parts of the beam-column joint. The variable stiffness energy dissipation device is composed of an energy dissipation device made of a combination of steel parts, an outer slope plate, a middle slope plate, an inner plane plate, a brake pad, a pressure type high-strength bolt, a friction type high-strength bolt, and a disc spring. The two middle slope plates with friction bolt holes and undulating surfaces are welded on the friction connecting plate to form a whole, and the friction fixing plate welded on the friction connecting plate is installed with a sufficient number and strength of pressure type high-strength bolts to connect the middle slope plate and the prefabricated concrete column into a whole. The brake pad is embedded between the inner plane plate and the middle slope plate, and the inner plane plate, the middle slope plate, the outer slope plate and the brake pad are connected into a whole by the friction type high-strength bolt to form the variable stiffness energy dissipation device.

[0041] The device is mainly used for improving the energy dissipation capacity of the fabricated concrete frame structure under the action of earthquakes, effectively eliminating or reducing the residual deformation of the structure under the action of earthquakes, and improving the assembly efficiency of the structure.

[0042] The utility model discloses in view of the deficiency of the conventional self-resetting prestressed concrete frame joint connection method, tightly integrates "variable stiffness energy dissipation" and "low prestress reset", realizes multi-stage starting and variable stiffness after starting by using variable stiffness energy dissipation device, controls high-order modal effect through variable stiffness, increases energy dissipation capacity through variable friction, thereby reducing the inter-story drift angle and acceleration of the self-resetting prestressed concrete frame structure.

[0043] Currently, the self-resetting prestressed concrete frame nodes based on friction energy dissipater only have a single starting force. Although the initial lateral stiffness of the overall structure is large, once the friction of the energy dissipater is started, the gap between the beam-column nodes is opened, and the lateral stiffness of the structure is mainly provided by the prestressed reinforcement, and the structural stiffness is significantly reduced. Under the action of strong earthquakes, the inter-story stiffness is significantly weakened, which easily leads to the self-resetting prestressed concrete frame to produce obvious high-order modal effects, the structure deformation is easy to concentrate, the local floor displacement angle is large, the non-structural member damage is increased, and the post-earthquake reset ability of the structure is also affected. The double-slope friction variable stiffness semi-self-resetting concrete beam-column node device using the technical scheme, under the action of earthquakes, the relative deformation of the beam-column drives the relative sliding between the middle slope steel plate and the inner and outer slope steel plates. The device is in the first undulating surface sliding section at the first starting, the inner and outer form a distance and continuously increase, compress the disc spring, continuously increase the normal pressure of the friction surface, and then increase the friction force, so that the variable stiffness energy dissipater has a second stiffness. When sliding to the second undulating surface section, the variable stiffness energy dissipater is started for the second time, and the friction force is continuously increased, so that the variable stiffness energy dissipater has a third stiffness. In the design process, the second and third starting displacements and stiffnesses of the variable stiffness energy dissipater can be effectively controlled by adjusting the angle of the undulating surface section, so as to improve the recoverable performance of the structure under strong earthquakes.

[0044] Since the beam-column embedded steel plates of the node are tightly attached together after node assembly, the node is equivalent to being preassigned a rotation point, and the movement form of the beam-column is rigid body rotation around the rotation point during the earthquake process, which effectively reduces or even eliminates the deformation of the beam-column itself. The connection form of the beam-column end and the variable stiffness energy dissipater and the embedded steel plate specially designed to prevent local damage can effectively avoid local damage (such as the end of the precast beam and column being crushed) during the deformation process of the structure. Therefore, the main structural members such as beams and columns remain in the elastic stage after the earthquake, thereby facilitating the reuse and reassembly of the components. All variable stiffness energy dissipaters are connected by bolts, so the replacement of the variable stiffness energy dissipaters is relatively convenient.

[0045] As shown in Figure 12 The utility model has three-section "multi-section flag-shaped" hysteresis curve, which can not only meet the seismic requirements of the structure under small earthquakes and medium earthquakes, but also better consume energy under strong earthquakes; the inter-story angular displacement and floor acceleration of the structure under small earthquakes, medium earthquakes and strong earthquakes are significantly reduced; the utility model has the advantages of small post-earthquake residual deformation and light structural damage, and avoids obvious plastic deformation of the main structural members such as precast concrete beams and columns.

[0046] Unlike the existing high prestressed self-centering concrete frame, low prestress is required to be applied during the installation of the prestressed tendon to provide self-centering force for the joint so that the deformation of the structure under the action of the earthquake can be restored to a position that is easy to repair, rather than emphasizing the complete reset of the joint. The low prestress can effectively improve the energy dissipation ratio and reduce the damage of the beam and column while ensuring that the residual inter-story drift angle of the structure is within the repairable range. Moreover, the structure assembly is more convenient and fast. The prestress applied by the prestressed tendon can be changed according to the needs, and the self-centering ability of the joint can be controlled by changing the prestress applied by the prestressed tendon, the sectional area of the prestressed tendon and the distance of the sectional center axis.

[0047] All components can be processed according to the needs at a non-construction site, and then transported to the construction site for assembly according to the needs. The whole assembly process is a dry operation. From the processing of the components to the production of the connecting parts, all can be completed in the factory, which can effectively control the labor cost, engineering progress and engineering quality compared with the general cast-in-place joint and wet connection.

[0048] The initial prestress of the prestressed tendon and the pre-tightening force applied to the friction plate are easy to control, so the stiffness of the joint can be effectively controlled in the design and construction according to the engineering requirements. The variable stiffness energy dissipation device is installed at the top and bottom of the prestressed concrete beam rather than the central axis position. This arrangement of the variable stiffness energy dissipation device can increase the force arm of the friction force and significantly improve the problem of insufficient stiffness of the structure in the form of the current semi-rigid joint.

[0049] The above only describes the preferred embodiments of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A low pre-stressed biaxial surface frictional variable stiffness self-centering concrete beam-column joint device, characterized in that: The application relates to a precast concrete column (1), a precast concrete beam (2) and a variable stiffness energy dissipation device, wherein the precast concrete beam (2) is arranged on the side of the precast concrete column (1) through the variable stiffness energy dissipation device; the variable stiffness energy dissipation device comprises friction end plates (3), friction connecting plates (4), friction fixing plates (5), outer slope steel plates (6), middle slope steel plates (7), brake pads (8), inner plane steel plates (9) and friction type high-strength bolts (10); the friction fixing plates (5) are arranged on the side of the precast concrete column (1); the two friction fixing plates (5) are connected into a whole through the friction connecting plates (4); the middle slope steel plates (7) are connected to the friction connecting plates (4) to form a whole; the middle slope steel plates are connected to the precast concrete column (1) into a whole through the friction bolt holes reserved in the friction fixing plates (5) by the pressure type high-strength bolts (11); the two inner plane steel plates (9) are symmetrically arranged on the top and bottom of the precast concrete beam (2); the two inner plane steel plates (9) are connected into a whole through the friction end plates (3); the brake pads (8) are arranged in the partial area between the inner plane steel plates (9) and the outer slope steel plates (6); the inner plane steel plates (9) and the outer slope steel plates (6) are connected to the precast concrete beam (2) into a whole through the friction type high-strength bolts (10); the middle slope steel plates (7) are arranged in the remaining area between the outer slope steel plates (6) and the inner plane steel plates (9).

2. The low prestressed biaxial frictional stiffness and self-centering concrete beam-column joint device according to claim 1, wherein: The friction type high-strength bolts (10) are provided with disc springs (21) located outside the outer slope steel plates (6).

3. The low prestressed biaxial frictional stiffness and self-centering concrete beam-column joint device according to claim 2, wherein: The disc springs (21) are arranged at the end of the friction type high-strength bolts (10) and the pressure type high-strength bolts (11).

4. The low prestressed double-sloped surface frictional variable rigidity self-centering concrete beam-column joint device according to claim 3, characterized in that: The first friction bolt holes (14) reserved in the precast concrete beam (2), the second friction bolt holes (15) in the inner plane steel plates (9) and the fourth friction bolt holes (17) in the outer slope steel plates (6) have the same hole diameter, which is smaller than that of the third friction bolt holes (16) in the middle slope steel plates (7).

5. The low prestressed biaxial frictional stiffness and self-centering concrete beam-column joint device according to claim 4, wherein: The friction type high-strength bolts (10) are connected and fixed to the precast concrete beam (2) after passing through the fifth friction bolt holes (18), the fourth friction bolt holes (17), the third friction bolt holes (16), the second friction bolt holes (15) and the first friction bolt holes (14).

6. The low prestressed biaxial frictional stiffness and self-centering concrete beam-column joint device of claim 5, wherein: The opposite sides of the outer slope steel plates (6) and the middle slope steel plates (7) are arranged as undulating surfaces, and the undulating surfaces of the two are interlaced and embedded.

7. The low prestressed biaxial frictional stiffness and self-centering concrete beam-column joint device according to claim 6, wherein: Horizontal prestressed tendons (12) are arranged in the precast concrete column (1) and the precast concrete beam (2).

8. The low prestressed biaxial frictional stiffness and self-centering concrete beam-column joint device according to claim 7, wherein: The brake pads (8) are embedded in the inner plane steel plates (9) through grooves, and the brake pads (8) are kept as a whole with the inner plane steel plates (9).

9. The low prestressed biaxial frictional stiffness and self-centering concrete beam-column joint device according to claim 8, wherein: The friction fixing plates (5) are fixed on the side of the precast concrete column (1) through the pressure type high-strength bolts (11).

10. The low prestressed biaxial frictional stiffness and self-centering concrete beam-column joint device according to claim 9, wherein: The two slopes of the outer slope steel plates (6) and the middle slope steel plates (7) are the same.

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