An assembled CFST-RC column conversion node with seismic isolation bearings and its construction method

Abstract

The present invention relates to an assembled CFST-RC column conversion node with a seismic isolation bearing and a construction method thereof, comprising: a seismic isolation bearing and a damping device, the seismic isolation bearing comprising a shape memory alloy core column, the top end of the shape memory alloy core column being cast in a steel tube concrete column, and the bottom end of the shape memory alloy core column being cast in a reinforced concrete column. The beneficial effect of the present invention is that by reserving a cavity when casting the steel tube concrete column and the reinforced concrete column, after the steel tube concrete column, the seismic isolation bearing and the reinforced concrete column are assembled, it is only necessary to cast concrete in the cavity to achieve a reliable connection between the seismic isolation bearing, especially the shape memory alloy core column, and the concrete in the steel tube concrete column and the reinforced concrete column, thereby better meeting the force requirements, self-resetting ability and safety of the node under earthquake action of the node, and the production and installation are simple, rapid assembly can be achieved, and economic benefits are high.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel structures and composite structures, and in particular relates to an assembled CFST-RC column conversion node with a seismic isolation support and a construction method thereof. Background Art

[0002] In recent years, my country has vigorously promoted prefabricated construction, which is seen as a key future development direction for the country's construction industry. Active implementation and vigorous development of prefabricated construction across various regions have accelerated its development. In prefabricated projects for mid- and low-level structures of large-scale public infrastructure, the upper structure often has large spans and high floor heights, placing high demands on the load-bearing structure's bearing capacity. Meanwhile, the lower structure often has low floor heights and is connected to the foundation, placing high demands on durability. Therefore, in actual prefabricated projects, a structure with a CFST (concrete-filled steel tube) frame on the upper level and RC (reinforced concrete) columns on the lower level is often used, with the two transitioning via transfer joints.

[0003] Under the action of an earthquake, the structure will produce a dynamic response, causing the structure to generate large internal forces or even be damaged, and after the earthquake, there are also problems such as excessive residual deformation and high maintenance costs. Therefore, engineering structure seismic isolation technology is often used in structural design. Engineering structure seismic isolation is a technical means of isolating the building structure from the ground by setting up a seismic isolation device, so that the building can move relatively freely on the seismic isolation device, extending the basic period of the building structure, and thus avoiding the structural resonance effect. In actual engineering, an isolation layer is often added between the upper structure and the lower structure or the foundation, and seismic isolation bearings are installed to make a soft connection between the upper structure and the lower structure. However, traditional seismic isolation bearings are mostly elastomers or only use lead cores for energy dissipation. They have insufficient energy dissipation capacity and poor tensile properties. They are easily broken under the action of an earthquake, resulting in poor self-reset performance of the structure and prone to large residual deformation.

[0004] Dampers are often used in engineering to reduce vibration and energy consumption. During earthquakes, they generate a damping force to dissipate the energy generated by the earthquake and reduce stress in the structure. Currently, dampers commonly used in building structures include metal dampers, viscoelastic dampers, friction dampers, and viscous liquid dampers. However, these dampers often suffer from significant temperature sensitivity, high maintenance requirements, poor frequency sensitivity, and poor adjustability.

[0005] Therefore, it is urgent to design a node form equipped with seismic isolation supports, which has the characteristics of easy assembly and low construction difficulty. On the premise of meeting the safety and normal use requirements such as strength, stiffness, and stability, the deformation performance and energy consumption capacity of the node and the overall structure can be improved, and the seismic performance of the structure can be enhanced. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide an assembled CFST-RC column conversion node with a seismic isolation support and a construction method thereof.

[0007] This assembled CFST-RC column transition node with a seismic isolation support includes: a seismic isolation support and a damping device. The seismic isolation support includes a shape memory alloy core column, the top end of the shape memory alloy core column is cast in the steel tube concrete column, and the bottom end of the shape memory alloy core column is cast in the reinforced concrete column;

[0008] Several damping devices are arranged around the shape memory alloy core column. The damping devices include an electromagnetic shielding tube and a metal tube. The bottom end of the electromagnetic shielding tube is hinged to the top surface of the reinforced concrete column. A cylindrical electromagnet is provided on the inner wall of the electromagnetic shielding tube. A permanent magnet is provided in the center of the electromagnetic shielding tube. The metal tube is inserted between the cylindrical electromagnet and the permanent magnet. The top end of the metal tube is hinged to the bottom surface of the steel tube concrete column.

[0009] Preferably, the seismic isolation bearing includes a rubber seismic isolation column, which is arranged between the steel tube concrete column and the reinforced concrete column, and the rubber seismic isolation column is sleeved on the outside of the shape memory alloy core column; the rubber seismic isolation column includes a steel plate and a rubber sheet, which are arranged at intervals and both have a core hole for the shape memory alloy core column to pass through.

[0010] Preferably, a rubber ring is fixed to the bottom end of the metal tube, and the inner wall of the cylindrical electromagnet and the outer wall of the permanent magnet are both wrapped with rubber sheets. A vertical channel between the metal tube and the rubber ring is formed between the rubber sheets of the cylindrical electromagnet and the permanent magnet. The width of the rubber ring is greater than the thickness of the metal tube wall, and the width of the vertical channel is less than or equal to the width of the rubber ring. When the metal tube slides in the vertical channel, the rubber ring and the rubber sheets on both sides of the vertical channel rub against each other.

[0011] Preferably, the thickness of the rubber sheet increases and the width of the vertical channel decreases from the center height to the upper and lower ends of the cylindrical electromagnet and the permanent magnet.

[0012] Preferably, a top plate and a bottom plate are provided on the top of the electromagnetic shielding tube. The bottom plate is closed, and an opening corresponding to the cross-sectional shape of the metal tube is opened on the top plate for inserting the metal tube. Reset springs are respectively provided between the rubber ring and the top plate and between the rubber ring and the bottom plate. The reset springs are arranged on the outside of the metal tube.

[0013] The construction method of the assembled CFST-RC column transfer node with seismic isolation bearings includes the following steps:

[0014] S1: Cast the steel tube concrete column and embed the first vertical longitudinal reinforcement, leaving some space at the bottom;

[0015] S2: Cast reinforced concrete columns and embed the second vertical longitudinal reinforcement, and install a steel sleeve on the top;

[0016] S3: An upper perforated steel plate is provided on the upper connecting plate of the seismic isolation support, and a lower perforated steel plate is provided below the lower connecting plate; a shape memory alloy core column is inserted, and an upper connector and a lower connector are threadedly connected at both ends of the shape memory alloy core column;

[0017] S4: Anchor the seismic isolation bearing and the first vertical longitudinal reinforcement to form a cavity at the bottom of the steel tube concrete column; after the entire column is hoisted, anchor the seismic isolation bearing and the second vertical longitudinal reinforcement to form a cavity in the steel sleeve;

[0018] S5: Hingedly install the damping device between the upper connecting plate and the lower connecting plate; cast the cavity.

[0019] Preferably, in step S3, the seismic isolation bearing includes an upper connecting plate and a lower connecting plate; in step S4, the edge of the upper perforated steel plate is fitted with the inner wall of the bottom end of the steel tube of the steel tube concrete column, and a cavity is formed between the upper perforated steel plate, the steel tube and the bottom surface of the concrete in the cast steel tube concrete column; the lower perforated steel plate is fitted with the steel sleeve at the top of the reinforced concrete column, and a cavity is also formed between the lower perforated steel plate, the steel sleeve and the top surface of the reinforced concrete column.

[0020] Preferably, the seismic isolation bearing includes an upper connecting head and a lower connecting head, which are respectively fixed to the upper and lower ends of the shape memory alloy core column by threads, and the upper connecting plate, the lower connecting plate and the seismic isolation bearing are fixed as one. The outer surfaces of the upper connecting head and the lower connecting head are provided with anchor bars. The upper connecting head and the lower connecting head are respectively located in the cavity of the steel tube concrete column and the reinforced concrete column. In step S5, after the cavity is cast, the upper connecting head and the lower connecting head are respectively cast as one with the steel tube concrete column and the reinforced concrete column.

[0021] Preferably, the bottom end of the first vertical longitudinal reinforcement extends below the lower end of the steel tube of the steel tube concrete column, the bottom end of the first vertical longitudinal reinforcement passes through the upper perforated steel plate and the upper connecting plate, and is anchored below the upper connecting plate; the top end of the second vertical longitudinal reinforcement extends above the upper end of the steel sleeve, the top end of the second vertical longitudinal reinforcement passes through the lower perforated steel plate and the lower connecting plate, and is anchored above the lower connecting plate; the damping device is installed on the outside of the first vertical longitudinal reinforcement and the second vertical longitudinal reinforcement.

[0022] The beneficial effects of the present invention are:

[0023] 1) The present invention reserves a cavity when casting the steel tube concrete column and the reinforced concrete column. After the steel tube concrete column, the seismic isolation bearing and the reinforced concrete column are assembled, it is only necessary to cast concrete in the cavity to achieve a reliable connection between the seismic isolation bearing, especially the shape memory alloy core column, and the concrete in the steel tube concrete column and the reinforced concrete column, thereby better meeting the force requirements, self-resetting ability and safety of the node under earthquake action. In addition, the production and installation are simple, rapid assembly can be achieved, and the economic benefits are high.

[0024] 2) The present invention provides a damping device at the isolation support. While satisfying the node isolation function, the damping device generates a damping force in a very short time through the electromagnetic principle, limits the lateral displacement of the column, and dissipates the energy generated by the earthquake to reduce the impact of the earthquake on the structure, and compensates for the partial load capacity lost after the shape memory alloy core column is bent; and because the damping device columns are arranged equidistantly around the circumference, they can play a role in the inter-story displacement occurring in all directions, thereby quickly reducing the amplitude of the structure; and the resistance size can be adjusted in real time according to demand, so that the inter-story displacement can be precisely controlled.

[0025] 3) The magnetic field strength at both ends of the cylindrical electromagnet in the damping device of the present invention is stronger than that in the middle. Therefore, the greater the inter-story displacement, the greater the resistance generated by the damping force. This can cope with the impact of earthquakes of varying intensities and is more conducive to the movement of the metal tube in the direction that reduces the damping force, which is beneficial to the recovery of the damping device. By providing rubber sheets on the surfaces adjacent to the cylindrical electromagnet and the permanent magnet, the resistance is increased through friction between the rubber ring and the rubber sheets on both sides. The thickness of the rubber sheet is further varied, so that the further the rubber ring deviates from the center, the greater the friction resistance, which also plays a role in facilitating recovery.

[0026] 4) The present invention is provided with a self-resetting device, which includes a shape memory alloy core column in the seismic isolation support and a reset spring in the damping device; due to the martensite-austenite phase transformation characteristics of the shape memory alloy itself, after the earthquake action is removed, the shape memory alloy rod returns to its original position, and at the same time the reset spring recovers its deformation, pulling the rubber ring back to the middle height of the electromagnetic shielding tube, so that the node has good self-resetting ability. When the structure undergoes inter-layer displacement or the upper and lower columns rotate relative to each other, the self-resetting device can provide a restoring force to achieve self-resetting to reduce or eliminate residual deformation of the structure, and can meet certain stiffness requirements.

[0027] 5) The damping devices used in the present invention are arranged equidistantly along the circumference of the column, and can take effect on interlayer displacement occurring in all directions, thereby quickly reducing the amplitude of the structure; and the damping force that the damping device can provide can be obtained by controlling the magnetic strength of the magnet through current, so the resistance can be adjusted in real time according to demand, thereby achieving precise control of interlayer displacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of the CFST-RC column conversion node of the present invention;

[0029] Figure 2 It is a structural schematic diagram of the node of the present invention;

[0030] Figure 3 This is a schematic structural diagram of the present invention after the seismic isolation support is connected to the upper and lower perforated steel plates;

[0031] Figure 4 This is a schematic structural diagram of the seismic isolation support of the present invention after assembly;

[0032] Figure 5 This is a front view of the seismic isolation support of the present invention after assembly;

[0033] Figure 6 It is a structural schematic diagram of the damping device of the present invention;

[0034] Figure 7 Schematic diagram of the internal structure of the damping device of the present invention;

[0035] Figure 8 It is a schematic structural diagram of the cylindrical electromagnet and the permanent magnet of the present invention;

[0036] Figure 9 It is a top view of the structure of the cylindrical electromagnet and the permanent magnet of the present invention;

[0037] Figure 10 It is a schematic diagram of the magnetic field generated by the cylindrical electromagnet and the permanent magnet of the present invention;

[0038] Figure 11 It is a schematic diagram of the structure of the node of the present invention when it is assembled;

[0039] Figure 12 It is a schematic diagram of the structure of the node of the present invention after the concrete pouring in the cavity is completed.

[0040] Explanation of the accompanying drawings: steel tube concrete column 1, reinforced concrete column 2, upper perforated steel plate 31, lower perforated steel plate 32, seismic isolation bearing 4, damping device 5, cavity 6, limiting ring 601, concrete in the cavity 602, steel tube 101, first vertical longitudinal reinforcement 102, steel sleeve 201, second vertical longitudinal reinforcement 202, second insertion hole 301, second through-rebar hole 302, rubber seismic isolation column 401, core hole 402, shape memory alloy core column 403, upper connector 4031, lower connector 4032, anchoring bar 4033, upper connecting plate 404, lower connecting plate 405, first insertion hole 4041, first through-rebar hole 4042, electromagnetic shielding tube 501, cylindrical electromagnet 502, permanent magnet 503, metal tube 504, rubber ring 505, return spring 506, spherical hinge 507. DETAILED DESCRIPTION

[0041] The present invention will be further described below with reference to the following examples. The following examples are provided only to facilitate understanding of the present invention. It should be noted that, without departing from the principles of the present invention, it is possible for a person skilled in the art to make various modifications to the present invention, and such improvements and modifications fall within the scope of the claims of the present invention.

[0042] Example 1

[0043] As an example, Figures 1 to 12 As shown, this assembled CFST-RC column conversion node with seismic isolation bearings is a connection node between the upper steel tube concrete column 1 and the lower reinforced concrete column 2. It is intended to reduce the dynamic response of the seismic action on the structure by the seismic isolation device under the action of an earthquake, prevent the seismic action from being transmitted upward, and thus reduce the degree of damage to the building and its internal facilities in the earthquake; when inter-layer displacement occurs in the upper and lower structures, the electromagnetic induction in the damping device 5 generates a damping force to dissipate energy, which has a fast response speed, strong adjustability, controllable energy, low maintenance cost, good energy dissipation and shock absorption capacity, and the energy dissipation elements are easy to disassemble and replace; at the same time, the shape memory alloy core column 403 can provide rotational stiffness and a certain energy dissipation capacity, which can allow the node to undergo large inter-layer displacement and deformation, and will not lose the initial stiffness after large deformation; after the earthquake, the shape memory alloy core column 403 and the damping device 5 jointly perform self-reset, thereby reducing or eliminating the residual deformation of the structure.

[0044] The concrete-filled steel tube column 1 and the reinforced concrete column 2 are respectively provided with a plurality of circumferential first vertical longitudinal bars 102 and second vertical longitudinal bars 202 arranged in the same manner, and the vertical longitudinal bars are disconnected at nodes.

[0045] The assembled CFST-RC column transition node with seismic isolation bearings includes: seismic isolation bearings 4 and damping devices 5. Seismic isolation bearings 4 include rubber isolation columns 401 and shape memory alloy core columns 403. The top of the shape memory alloy core column 403 is cast in the steel tube concrete column 1, and the bottom of the shape memory alloy core column 403 is cast in the reinforced concrete column 2. The rubber isolation column 401 is arranged between the steel tube concrete column 1 and the reinforced concrete column 2, and is sleeved on the outside of the shape memory alloy core column 403. The rubber isolation column 401 includes steel plates and high-damping rubber sheets, which are arranged at intervals and each has a core hole 402 for the shape memory alloy core column 403 to pass through. The side surface of the rubber isolation column 401 is coated with anti-corrosion paint to prevent rust on the steel plate and aging of the high-damping rubber sheet, which would affect the seismic isolation effect and energy dissipation performance of the node. The diameter of the shape memory alloy core column 403 is smaller than the core hole diameter of the rubber seismic isolation column 401, so that a movable gap is left between the shape memory alloy core column 403 and the rubber seismic isolation column 401 when the shape memory alloy core column 403 is deformed, thereby preventing the shape memory alloy core column 403 and the rubber seismic isolation column 401 from being squeezed against each other and damaged when interlayer displacement occurs in the structure, thereby causing functional failure.

[0046] The shape memory alloy core column 403 has a larger cross-section to prevent buckling and instability when under pressure, thereby improving its load-bearing capacity and deformation capability. In this embodiment, the core hole 402 in the rubber isolation column 401 and the cross-section of the shape memory alloy core column 403 are circular, and there is only one core hole 402 and shape memory alloy core column 403. However, multiple core holes 402 and shape memory alloy core columns 403 can be provided, or the cross-sections can adopt other shapes, but the shapes of the two must match.

[0047] Several damping devices 5 are arranged around the shape memory alloy core column 403. These devices comprise an electromagnetic shielding tube 501 and a metal tube 504. The electromagnetic shielding tube 501 is made of a highly conductive metal and coated both internally and externally with a conductive coating, effectively absorbing electromagnetic waves and providing a degree of corrosion resistance. The bottom end of the electromagnetic shielding tube 501 is hinged to the top surface of the reinforced concrete column 2 via a spherical hinge 507. A cylindrical electromagnet 502 is located on the inner wall of the electromagnetic shielding tube 501, and a permanent magnet 503 is located at its center. A metal tube 504 is inserted between the cylindrical electromagnet 502 and the permanent magnet 503. The top end of the metal tube 504 is hinged to the bottom surface of the steel-concrete-filled steel tube column 1 via a spherical hinge 507. Initially, the damping device 5 remains vertical. Due to the connection structure of the spherical hinge 507, the damping device can move in response to inter-story displacement in various directions, generating a damping force that acts in the opposite direction of the column end's lateral displacement angle.

[0048] When the damping device 5 is working, the metal tube 504 extends into the cylindrical electromagnet 502 to cut the magnetic flux lines, generating an induced current on the metal tube 504, thereby generating a damping force in the opposite direction to the displacement between structural layers and the relative rotation angle of the column end.

[0049] This node structure can also be extended to structural forms in which both the upper and lower parts are steel tube concrete columns 1, and both the upper and lower parts are reinforced concrete columns 2.

[0050] The column cross-sectional shapes used in the nodes include but are not limited to round steel tube concrete columns and round reinforced concrete columns. For example, it can be extended to structural forms with different cross-sectional shapes such as square steel tube concrete columns and square reinforced concrete columns.

[0051] Example 2

[0052] As another embodiment, this embodiment 2 proposes, based on the embodiment 1, a more specific assembled CFST-RC column conversion node with a seismic isolation support, the structure of the damping device 5 is as follows: Figures 6 to 10 As shown:

[0053] The cylindrical electromagnet 502 consists of a cylindrical iron core wound with several turns of copper coils coated with corrosion-resistant paint. It is placed inside and fixed to the electromagnetic shielding tube 501. The cylindrical iron core is a hollow, cylindrical structure with an opening. Its outer diameter is slightly smaller than the inner diameter of the electromagnetic shielding tube 501, ensuring that the copper coils on the cylindrical iron core can be wound densely. The copper coils are connected to an external power source via a wire, providing a strong current to the cylindrical electromagnet 502 and generating a strong magnetic field. When energized, the magnetic poles on either side of the opening of the cylindrical super-strong electromagnet are different. A solid cylindrical permanent magnet 503 is installed inside the cylindrical iron core. The two magnetic poles of the permanent magnet 503 correspond to the two half-cylinders divided along the plane through the axis. The magnetic poles of the two half-cylinders are different from the magnetic poles of the cylindrical iron core on the same side. The diameter of the permanent magnet 503 is slightly smaller than the inner diameter of the cylindrical iron core, leaving a gap between the two to allow the piston movement of the metal tube 504.

[0054] The coils and cores of the cylindrical electromagnet 502 and the permanent magnet 503 are covered with a high-damping silicone rubber sheet; the gap between the inside of the cylindrical electromagnet 502 and the permanent magnet 503 is filled with high-viscosity damping oil.

[0055] The metal tube 504 and the iron core are made of highly conductive materials such as iron, nickel, or copper, and the copper coil is tightly wound around the iron core. This allows the damping device 5 to generate a large induced current very quickly after the metal tube 504 moves as a piston within the cylindrical electromagnet 502. This allows the damping device 5 to respond immediately and activate when an earthquake occurs. Furthermore, even under minor vibrations caused by small earthquakes, sufficient damping force can be generated to limit lateral displacement of the column end at the node.

[0056] A rubber ring 505 is fixed to the bottom end of the metal tube 504. The inner wall of the cylindrical electromagnet 502 and the outer wall of the permanent magnet 503 are both wrapped with a high-damping silicone rubber sheet. A vertical channel is formed between the rubber sheets of the cylindrical electromagnet 502 and the permanent magnet 503, connecting the metal tube 504 and the rubber ring 505. The width of the rubber ring 505 is greater than the thickness of the metal tube 504 wall, and the width of the vertical channel is less than or equal to the width of the rubber ring 505. When the metal tube 504 slides within the vertical channel, the rubber ring 505 rubs against the rubber sheets on either side of the vertical channel. The high-damping silicone rubber sheet is non-conductive and has no shielding or absorption effect on electromagnetic waves. The rubber ring 505 is made of high-damping silicone rubber.

[0057] From the center height of the cylindrical electromagnet 502 and the permanent magnet 503 to the upper and lower ends, the thickness of the rubber sheet increases and the width of the vertical channel decreases, so that the friction of the rubber ring 505 is minimized when it is in the middle of the vertical channel, and the closer to the end, the greater the friction.

[0058] Electromagnetic shielding tube 501 is topped with a top plate and a bottom plate. The bottom plate is sealed and equipped with a rubber pad for accommodating the cylindrical electromagnet 502 and permanent magnet 503. The top plate is provided with a circular hole corresponding to the cross-sectional shape of the metal tube 504 for insertion. Return springs 506 are respectively provided between the rubber ring 505 and the top plate and between the rubber ring 505 and the bottom plate. Return springs 506 are located outside the metal tube 504. These return springs 506 are non-conductive and have no shielding or absorption effect on electromagnetic waves, thus having no effect on the distribution of the magnetic field or the intensity of the magnetic induction in the damping device.

[0059] It should be noted that the parts in this embodiment that are the same or similar to those in the second embodiment can be referenced to each other and will not be described in detail in this application.

[0060] Example 3

[0061] As another embodiment, based on the first and second embodiments, this third embodiment proposes a construction method for a prefabricated CFST-RC column transition node with a seismic isolation support, comprising the following steps:

[0062] S1: Cast the steel tube concrete column 1 and embed the first vertical longitudinal reinforcement 102, leaving the bottom of the steel tube 101 empty and not cast;

[0063] S2: Cast the reinforced concrete column 2 and embed the second vertical longitudinal reinforcement 202. Install a steel sleeve 201 on the top. The steel sleeve 201 is fixedly connected to the reinforced concrete column 2 with bolts. A temporary diagonal support is installed. The steel sleeve 201 is kept vertical, and its axis is kept aligned with the axis of the reinforced concrete column 2.

[0064] S3: The seismic isolation bearing 4 includes an upper connecting plate 404, a lower connecting plate 405, an upper connecting head 4031 and a lower connecting head 4032; an upper perforated steel plate 31 is provided on the upper connecting plate 404 of the seismic isolation bearing 4, and a lower perforated steel plate 32 is provided below the lower connecting plate 405; a shape memory alloy core column 403 is inserted, and the upper connecting head 4031 and the lower connecting head 4032 are threadedly connected at both ends of the shape memory alloy core column 403; the upper connecting head 4031 and the lower connecting head 4032 are respectively fixed to the upper and lower ends of the shape memory alloy core column 403 by threads, and the upper connecting plate 404, the lower connecting plate 405 and the seismic isolation bearing 4 are fixed as a whole, and the outer surfaces of the upper connecting head 4031 and the lower connecting head 4032 are provided with anchoring ribs 4033.

[0065] S4: Threads are provided on the portion where the lower end of the first vertical longitudinal reinforcement 102 extends beyond the bottom surface of the steel pipe 101 and the portion where the upper end of the second vertical longitudinal reinforcement 202 extends beyond the reinforced concrete column 2, and gasket connection nuts are set. The upper connecting plate 404 and the lower connecting plate 405 are respectively provided with first reinforcement holes 4042 at the positions corresponding to the first vertical longitudinal reinforcement 102 and the second vertical longitudinal reinforcement 202, allowing the first vertical longitudinal reinforcement 102 and the second vertical longitudinal reinforcement 202 to pass through.

[0066] The bottom end of the first vertical longitudinal reinforcement 102 extends to below the lower end of the steel tube 101 of the steel tube concrete column 1. The bottom end of the first vertical longitudinal reinforcement 102 passes through the upper perforated steel plate 31 and the upper connecting plate 404, and a gasket connecting nut is arranged under the upper connecting plate 404 to anchor the seismic isolation bearing 4 and the first vertical longitudinal reinforcement 102. The edge of the upper perforated steel plate 31 is fitted with the inner wall of the bottom end of the steel tube 101 of the steel tube concrete column 1, and a cavity 6 is formed between the upper perforated steel plate 31, the steel tube 101 and the bottom surface of the concrete in the poured steel tube concrete column 1.

[0067] After the overall hoisting, the top of the second vertical longitudinal reinforcement 202 extends to above the upper end of the steel sleeve 201, the top of the second vertical longitudinal reinforcement 202 passes through the lower perforated steel plate 32 and the lower connecting plate 405, and is anchored above the lower connecting plate 405, anchoring the seismic isolation bearing 4 and the second vertical longitudinal reinforcement 202, the lower perforated steel plate 32 and the steel sleeve 201 at the top of the reinforced concrete column 2 fit together, and the lower perforated steel plate 32, the steel sleeve 201 and the top surface of the reinforced concrete column 2 also form a cavity 6.

[0068] The upper connecting head 4031 and the lower connecting head 4032 are respectively located in the cavity 6 of the steel tube concrete column 1 and the reinforced concrete column 2.

[0069] S5: A damping device 5 is hingedly installed between the upper connecting plate 404 and the lower connecting plate 405. The damping device 5 is installed on the outside of the first vertical longitudinal rib 102 and the second vertical longitudinal rib 202. The upper end of the metal tube 504 and the lower end of the electromagnetic shielding tube 501 are installed with a spherical hinge 507, which are connected to the upper connecting plate 404 and the lower connecting plate 405 respectively. Figure 11 shown.

[0070] The cavity 6 is poured. The cavity 6 in the steel pipe 101 and the steel sleeve 201 is provided with at least one grouting hole and at least one slurry outlet hole. The slurry outlet hole is located at the top of the cavity 6 and the grouting hole is located at the bottom of the cavity 6. When pouring concrete in the cavity 6, concrete is injected through the grouting hole, and at the same time, all the bubbles in the cavity 6 are squeezed out upward through the slurry outlet hole, which can effectively ensure the density of the concrete poured in the cavity 6. After the cavity 6 is poured, the upper connector 4031 and the lower connector 4032 are respectively integrated with the steel tube concrete column 1 and the reinforced concrete column 2 to enhance the shear resistance and pull-out resistance of the node when it withstands horizontal and vertical forces. Figure 12When pouring, the grouting material should be non-shrinkage high-strength grouting material, which has good self-flowing properties, small aggregates, and good self-compactness. It does not require vibration during pouring and can avoid clogging of the grouting and discharge channels. At the same time, it has high strength and can significantly improve the load-bearing and deformation resistance of the structure.

[0071] Example 4

[0072] As another embodiment, this fourth embodiment, based on the first to third embodiments, proposes a more specific construction method for a prefabricated CFST-RC column transfer node with a seismic isolation support:

[0073] The diameters of the upper and lower perforated steel plates 31 and 32 are slightly smaller than the inner diameter of the steel tube 101 of the steel tube concrete column 1, and their side surfaces are coated with lubricating oil to avoid large friction with the steel tube 101 of the steel tube concrete column 1 or the inner wall of the steel sleeve 201 of the reinforced concrete column 2, thereby preventing them from being installed in the designated position.

[0074] The upper perforated steel plate 31 and the lower perforated steel plate 32 should preferably be made of thicker steel plates so that they can withstand larger horizontal forces under the action of larger earthquakes. There is at least one second insertion hole 301 at the center of the upper perforated steel plate 31 and the lower perforated steel plate 32, which allows the shape memory alloy core column 403 to pass through, and its diameter is larger than the diameter of the shape memory alloy core column 403; the upper perforated steel plate 31 is provided with a second through-reinforcement hole 302 allowing the first vertical longitudinal reinforcement 102 to pass through at the position corresponding to the first vertical longitudinal reinforcement 102, and the lower perforated steel plate 32 is provided with a second through-reinforcement hole 302 allowing the second vertical longitudinal reinforcement 202 to pass through at the position corresponding to the second vertical longitudinal reinforcement 202.

[0075] The upper connector 4031 and the lower connector 4032 are provided with rubber collars at their bottom and top ends, respectively. These collars are positioned in the gaps between the first and second insertion holes 4041 and 301, respectively, and the shape memory alloy core column 403, thereby providing a better seal during grouting and preventing grout leakage. Before pouring the cementitious material into the cavity 6, a non-shrinkage high-strength grouting material is used to seal the gaps between the first and second insertion holes 4041 and 301, respectively, and the shape memory alloy core column 403, preventing grout leakage during subsequent construction.

[0076] The protruding portions of the ends of the first vertical longitudinal reinforcement 102 and the second vertical longitudinal reinforcement 202 are coated with corrosion-resistant paint to prevent the steel bars from rusting.

[0077] It should be noted that the parts in this embodiment that are the same or similar to those in the third embodiment can be referenced to each other and will not be described in detail in this application.

[0078] Example 5

[0079] As another embodiment, this fourth embodiment, based on the first to third embodiments, proposes a method for using the assembled CFST-RC column transfer node with seismic isolation bearings:

[0080] The damping device 5 is equipped with a control program and consists of a magnetic flux density meter, a displacement meter, an accelerometer, and a computer. The magnetic flux density meter can detect the magnetic field strength of the cylindrical electromagnet 502 in real time; the displacement meter can detect the interlayer displacement of the structure, especially at the joints, in real time; and the accelerometer can monitor the earthquake intensity in real time. These three devices are connected to the computer, which can monitor the magnetic flux density, displacement, and acceleration. The computer then adjusts the input voltage and controls the current to adjust the damping force required for different vibration scenarios.

[0081] After power is applied, the magnetic poles on both sides of the opening of the cylindrical electromagnet 502 are different; a solid cylindrical permanent magnet 503 is provided in the inner layer of the cylindrical core, and the two magnetic poles correspond to the two half cylinders divided along the plane through the axis, and the magnetic poles of the two half cylinders are different from the magnetic poles of the cylindrical core on the same side. An approximately annular magnetic field can be generated between the cylindrical electromagnet 502 and the permanent magnet 503, as shown in FIG. Figure 10 shown.

[0082] When the node provided by the present invention produces inter-layer displacement in the structure under an earthquake, the seismic isolation support with a damping device arranged at the node can, on the one hand, isolate the vibration caused by the lower reinforced concrete column 2 from being transmitted to the upper steel tube concrete column 1 during the earthquake, thereby playing a seismic isolation role and reducing the seismic response of the entire structure; on the other hand, it drives the metal tube 504 in the damping device 5 to cut the magnetic lines of force in the magnetic field generated by the cylindrical electromagnet 502, thereby generating an induced current on the metal tube 504, generating a magnetic field opposite to the original magnetic field, and then generating a damping force to hinder the displacement of the structure, reducing the dynamic response while dissipating the energy generated by the earthquake, thereby achieving the purpose of shock absorption and energy consumption; at the same time, the shape memory alloy core column 403 placed in the core hole 402 of the rubber seismic isolation column 401 can quickly enter yield and produce plastic deformation, which can consume part of the energy generated by the earthquake and has a certain energy consumption capacity.

[0083] In addition, the rubber ring 505 provided at the bottom end of the metal tube 504 generates friction with the rubber sheet wrapped around the cylindrical electromagnet 502 and the permanent magnet 503. The rubber ring 505 is made of high-damping rubber. When the rubber ring 505 undergoes interlayer displacement in the structure, thereby driving the metal tube 504 to move in the gap between the cylindrical electromagnet 502 and the permanent magnet 503, friction occurs between the rubber ring 505 and the high-damping silicone rubber sheet, which can slow down, absorb and dissipate part of the energy, thereby playing a shock-absorbing role. Moreover, due to the change in thickness of the rubber sheet, the greater the distance the rubber ring 505 moves, the greater the friction force it is subjected to, which is conducive to the recovery of the damping device 5.

[0084] The metal tube 504 performs piston motion in the cylindrical electromagnet 502, thereby driving the restoring spring 506 to stretch and contract, generating a restoring force in the opposite direction of the displacement between the structural layers, thereby reducing the dynamic response and amplitude of the structure caused by earthquake action and isolating the structure from smaller vertical vibrations.

[0085] The return spring 506 and the seismic isolation support 4 together constitute the node's self-resetting device. The return spring 506 and the shape memory alloy core column 403 can reduce or eliminate residual deformation caused by the earthquake after the earthquake, thereby achieving the structure's self-resetting function. After the earthquake is removed, the shape memory alloy core column 403 returns to its original position due to its martensite-austenite phase transformation characteristics. The return spring 506 exerts an unbalanced restoring force on the column, driving the column end to rotate, thereby reducing residual deformation of the structure and even returning it to its original position, achieving the purpose of self-resetting.

[0086] When the damping device 5 is working, it can monitor the displacement and acceleration of the structure under the action of the earthquake through a computer according to the predicted earthquake magnitude, adjust the voltage and thus adjust the strength of the magnetic field generated by the electromagnet, and then adjust the magnitude of the electromagnetic damping force. The displacement and amplitude of the structure can be accurately controlled within a certain range according to needs.

[0087] The magnetic field strength at both ends of the tubular electromagnet 502 in the damping device 5 is stronger than that in the middle. Therefore, when the interlayer displacement is greater, the resistance generated by the damping force is greater, which can cope with the impact caused by earthquakes of different intensities, and is more conducive to the metal tube 504 moving in the direction of smaller damping force, which is beneficial to the recovery of the damping device 5.

[0088] It should be noted that the parts in this embodiment that are the same or similar to those in embodiments one to four can be referenced to each other and will not be described in detail in this application.

[0089] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A construction method for an assembled CFST-RC column transfer node with a seismic isolation support, characterized in that: include: The seismic isolation support and damping device include a shape memory alloy core column, the top end of the shape memory alloy core column is cast in the steel tube concrete column, and the bottom end of the shape memory alloy core column is cast in the reinforced concrete column; Several damping devices are arranged around the shape memory alloy core column. The damping devices include an electromagnetic shielding tube and a metal tube. The bottom end of the electromagnetic shielding tube is hinged to the top surface of the reinforced concrete column. A cylindrical electromagnet is provided on the inner wall of the electromagnetic shielding tube. A permanent magnet is provided in the center of the electromagnetic shielding tube. The metal tube is inserted between the cylindrical electromagnet and the permanent magnet. The top end of the metal tube is hinged to the bottom surface of the steel tube concrete column. The following steps are involved: S1: Cast the steel tube concrete column and embed the first vertical longitudinal reinforcement, leaving some space at the bottom; S2: Cast reinforced concrete columns and embed the second vertical longitudinal reinforcement, and install a steel sleeve on the top; S3: An upper perforated steel plate is provided on the upper connecting plate of the seismic isolation bearing, and a lower perforated steel plate is provided below the lower connecting plate; a shape memory alloy core column is inserted, and an upper connector and a lower connector are threadedly connected at both ends of the shape memory alloy core column; in step S3, the seismic isolation bearing includes an upper connecting plate and a lower connecting plate; in step S4, the edge of the upper perforated steel plate is fitted with the inner wall of the bottom end of the steel tube of the steel tube concrete column, and a cavity is formed between the upper perforated steel plate, the steel tube, and the bottom surface of the concrete in the poured steel tube concrete column; the lower perforated steel plate is fitted with the steel sleeve at the top of the reinforced concrete column, and a cavity is also formed between the lower perforated steel plate, the steel sleeve, and the top surface of the reinforced concrete column; S4: Anchor the seismic isolation bearing and the first vertical longitudinal reinforcement to form a cavity at the bottom of the steel tube concrete column; after the entire column is hoisted, anchor the seismic isolation bearing and the second vertical longitudinal reinforcement to form a cavity in the steel sleeve; S5: Hingedly install the damping device between the upper connecting plate and the lower connecting plate; cast the cavity.

2. The construction method of the assembled CFST-RC column transfer node with seismic isolation bearings according to claim 1 is characterized in that: The seismic isolation bearing includes a rubber seismic isolation column, which is arranged between the steel tube concrete column and the reinforced concrete column, and the rubber seismic isolation column is sleeved on the outside of the shape memory alloy core column; the rubber seismic isolation column includes a steel plate and a rubber sheet, which are arranged at intervals and both have a core hole for the shape memory alloy core column to pass through.

3. The construction method of the assembled CFST-RC column transfer node with seismic isolation bearings according to claim 1 is characterized in that: A rubber ring is fixed at the bottom end of the metal tube, and the inner wall of the cylindrical electromagnet and the outer wall of the permanent magnet are wrapped with rubber sheets. A vertical channel between the metal tube and the rubber ring is formed between the rubber sheets of the cylindrical electromagnet and the permanent magnet. The width of the rubber ring is greater than the thickness of the metal tube wall, and the width of the vertical channel is less than or equal to the width of the rubber ring. When the metal tube slides in the vertical channel, the rubber ring and the rubber sheets on both sides of the vertical channel rub against each other.

4. The construction method of the assembled CFST-RC column transfer node with seismic isolation bearings according to claim 3 is characterized in that: From the middle height of the cylindrical electromagnet and the permanent magnet to the upper and lower ends, the thickness of the rubber sheet increases and the width of the vertical channel decreases.

5. The construction method of the assembled CFST-RC column transfer node with seismic isolation bearings according to claim 3 is characterized in that: The top of the electromagnetic shielding tube is provided with a top plate and a bottom plate. The bottom plate is closed, and the top plate is provided with an opening corresponding to the cross-sectional shape of the metal tube for inserting the metal tube. Reset springs are respectively provided between the surrounding rubber ring and the top plate and between the surrounding rubber ring and the bottom plate. The reset springs are provided on the outside of the metal tube.

6. The construction method of the assembled CFST-RC column transfer node with seismic isolation bearings according to claim 1 is characterized in that: The seismic isolation bearing includes an upper connecting head and a lower connecting head, which are respectively fixed to the upper and lower ends of the shape memory alloy core column by threads, and the upper connecting plate, the lower connecting plate and the seismic isolation bearing are fixed as one. The outer surfaces of the upper connecting head and the lower connecting head are provided with anchor bars. The upper connecting head and the lower connecting head are respectively located in the cavity of the steel tube concrete column and the reinforced concrete column. In step S5, after the cavity is cast, the upper connecting head and the lower connecting head are respectively cast as one with the steel tube concrete column and the reinforced concrete column.

7. The construction method of the assembled CFST-RC column transfer node with seismic isolation bearings according to claim 1 is characterized in that: The bottom end of the first vertical longitudinal reinforcement extends below the lower end of the steel tube of the steel tube concrete column, and the bottom end of the first vertical longitudinal reinforcement passes through the upper perforated steel plate and the upper connecting plate, and is anchored below the upper connecting plate; the top end of the second vertical longitudinal reinforcement extends above the upper end of the steel sleeve, and the top end of the second vertical longitudinal reinforcement passes through the lower perforated steel plate and the lower connecting plate, and is anchored above the lower connecting plate; the damping device is installed on the outside of the first vertical longitudinal reinforcement and the second vertical longitudinal reinforcement.

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