Self-resetting gradient aseismatic slender steel pipe concrete lattice column

Abstract

This invention discloses a self-resetting gradient seismic-resistant slender steel-concrete lattice column, comprising a steel-concrete lattice column member, energy-dissipating ducts, and self-resetting ducts. The energy-dissipating and self-resetting ducts are arranged alternately and uniformly layer by layer along the column height, welded to the column member using intersecting welds. The energy-dissipating ducts are high-ductility, low-yield-point steel tubes. The self-resetting duct comprises a left sleeve, a right sleeve, a reset leaf spring assembly, and a flexible metal hose. The reset leaf spring assembly provides the reset force through two spring steel plates, and its ends are fixed to the left and right sleeves by pads, positioning screws, and clamping devices. Following a seismic performance-based design method, based on the performance objectives of the column member, energy-dissipating duct, and self-resetting duct, the internal forces of each component under different levels of seismic loading are obtained using the continuous medium method. The bearing capacity and deformation capacity are then designed to achieve the gradient failure mode of the lattice column under seismic loading. By dissipating energy through the plastic deformation of the energy-dissipating duct, the column limbs are protected. The residual deformation after an earthquake is eliminated by the self-resetting duct. This can solve the problem of insufficient seismic toughness of slender steel tube concrete lattice columns during earthquakes, and can significantly increase the height of the connecting corridor and reduce the number of supporting columns under the corridor.

Description

Technical Field

[0001] This invention relates to a self-resetting gradient seismic-resistant slender steel tube concrete lattice column, and more particularly to a flat-jointed steel tube concrete lattice column suitable for the bottom of elevated corridors, which has multiple seismic defense lines during earthquakes and possesses self-resetting capability, belonging to the field of structural engineering technology. Technical Background

[0002] As the practice of connecting building towers with corridors becomes increasingly common, the requirements for the functionality and aesthetic design of these corridors are constantly rising. Designing elevated corridors with greater height and more complex shapes has become a key challenge in the design of interconnected high-rise buildings. To improve the utilization efficiency of the space beneath the corridors and achieve a lightweight and aesthetically pleasing architectural effect, the number and size of supporting columns should be minimized, making single-span frame structures the preferred option. However, traditional single-span frame structures have too few vertical members, low redundancy, and insufficient seismic toughness, making them prone to overall collapse under earthquakes. Furthermore, after the corridor is elevated, traditional vertical members tend to be too slender, making it difficult to meet the required slenderness ratio. Due to the significant deficiencies in the seismic performance of traditional single-span frame structures, elevated corridor structures have too many supporting members, severely limiting the elevated height. Therefore, developing a new, safe, economical, and aesthetically pleasing elevated corridor structural system has promising application prospects and economic value.

[0003] Elevated walkways consist of a bottom open-air floor and upper ordinary floors. The height of the open-air floor may reach or exceed 20 meters, significantly greater than that of the upper ordinary floors. Correspondingly, under seismic loading, the bending moments borne by the column tops and bottoms of the frame columns in the open-air floor are much greater than those in the upper floors, making these areas more prone to plastic hinges. When the frame columns in the open-air floor are made of ordinary reinforced concrete, steel, or steel-concrete composite columns, failure occurs when plastic hinges appear simultaneously at both the column top and bottom, lacking a second line of seismic defense. The failure process is short, the failure mode is sudden, and the seismic toughness is insufficient. The key to the success of an elevated walkway structural system is for the frame columns in the open-air floor to effectively dissipate seismic energy while maintaining structural stability, possessing both gradient failure modes and self-resetting capabilities.

[0004] Horizontally connected steel-concrete composite lattice columns are highly statically indeterminate structures formed by connecting multiple columns with horizontally connected tubes. The connecting tubes do not directly bear vertical loads. Based on seismic design principles, under earthquake conditions, if the connecting tubes yield first and dissipate seismic energy, they can protect the columns, creating a gradient failure mode where the connecting tubes fail before the column members. Replacing the single-member columns at the bottom of traditional single-span frames with horizontally connected steel-concrete composite lattice columns may solve the problem of insufficient seismic toughness in traditional single-span frames.

[0005] However, the current "Technical Specification for Steel-Concrete Composite Structures" treats steel-concrete composite lattice columns as equivalent to single-limb steel-concrete composite columns in its design, and calculates the internal forces of the column limbs and connecting tubes using a single-span multi-story frame model. To ensure that the connecting tubes provide sufficient constraint on the column limbs and prevent a single column limb from failing before the entire member, the linear stiffness of the connecting tubes is required to be no less than 6 times the linear stiffness of the column limbs, i.e., satisfying the strong connecting tube assumption. The failure mode of lattice columns designed using this method is that the column limbs fail before the connecting tubes. The connecting tubes, together with the tension-side and compression-side column limbs, form a composite section. When the member fails, the column limbs mainly bear axial tension and compression, which leads to poor rotational capacity of the composite section, low ductility, and insufficient energy dissipation capacity. If the linear stiffness of the connecting tubes is reduced, under seismic loading, the connecting tubes yield before the column limbs, significantly reducing the constraint capacity on the column limbs, making it difficult to guarantee the stability of the column limbs. Moreover, the plastic deformation of the connecting tubes makes it difficult to recover the lateral deformation of the lattice column, resulting in large residual deformation after the earthquake and making post-disaster repair very difficult. Traditional flat-jointed steel-concrete lattice columns have significant shortcomings in terms of failure modes, energy dissipation capacity, and recovery capacity, and cannot solve the problems of insufficient seismic toughness and large residual deformation after earthquakes in elevated corridor structures, which leads to difficulties in repair. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the present invention provides a self-resetting gradient seismic-resistant slender steel tube concrete lattice column to solve the problems of insufficient seismic toughness of elevated corridors during earthquakes and large residual deformation after earthquakes, which leads to difficulties in repair.

[0007] To achieve the above objectives, this invention provides a self-resetting gradient seismic-resistant slender steel-concrete composite lattice column. The structure includes a steel-concrete composite column leg, energy-dissipating ducts, and self-resetting ducts. The bearing capacity and deformation capacity of each component are determined according to the principle that the energy-dissipating duct yields before the column leg, while the self-resetting duct maintains elasticity and provides a restoring force. This design is primarily applicable to the bottom-level frame columns of elevated corridors. The energy-dissipating and self-resetting ducts are arranged alternately and uniformly layer by layer along the column height. The energy-dissipating ducts are made of high-ductility, low-yield-point steel pipes. The self-resetting duct includes a left sleeve, a right sleeve, a restoring leaf spring assembly with both ends tightly fixed, and a flexible metal hose protecting the gap between the left and right sleeves.

[0008] Furthermore, the steel-concrete composite column consists of four sections, with high-strength steel pipes filled with high-strength self-compacting micro-expansion concrete. The energy-dissipating ducts are connected to the column sections via intersecting welds, with four ducts per layer forming a square, evenly distributed along the height direction. They are circular steel pipes with high ductility and low yield point. The self-resetting ducts are arranged in the same manner as the energy-dissipating ducts, spaced apart along the height direction. The left and right sleeves of the self-resetting ducts are circular steel pipes, connected to the column sections via intersecting welds. Space is left between the left and right sleeves for deformation and installation, and a reset leaf spring assembly is installed inside, covered by a flexible metal hose.

[0009] Furthermore, the reset leaf spring assembly includes a first spring steel plate, a second spring steel plate, a left limiting bolt, an upper left pad, a lower left pad, a left tightening device, a first left tightening bolt hole, a second left tightening bolt hole, a right limiting bolt, an upper right pad, a lower right pad, a right tightening device, a first right tightening bolt hole, and a second right tightening bolt hole. The upper left pad is welded to the upper part of the inner wall of the left sleeve, and the lower left pad is welded to the lower part of the inner wall of the left sleeve. The upper right pad is welded to the upper part of the inner wall of the right sleeve, and the lower right pad is welded to the lower part of the inner wall of the right sleeve. All four pads have grooves on their straight edges, and the groove width is the same as that of the spring steel plate. Spring steel plate one has its left end pressed against the lower surface of the groove on the left pad and its right end pressed against the lower surface of the groove on the right pad, with PTFE plates on the contact surfaces. Spring steel plate two has its left end pressed against the upper surface of the groove under the left pad and its right end pressed against the upper surface of the groove under the right pad, with PTFE plates on the contact surfaces. Spring steel plate one has a limiting bolt hole on its left end, with a left limiting bolt, its end pressed against the left side of the left pad for positioning. Spring steel plate two has a limiting bolt hole on its left end, with a left limiting bolt pressed against the left side of the left pad for positioning. Spring steel plate two has a limiting bolt hole on its left end, with a right limiting bolt, its end pressed against the right side of the right pad for positioning, with a sliding clearance between the spring steel plate and the right pad. The left and right limiting bolts pass sequentially through spring steel plate one and spring steel plate two for vertical positioning.

[0010] Furthermore, the left tightening device includes a left top plate, a left bottom plate, a left wedge plate one, a left wedge plate two, a left tightening bolt one, and a left tightening bolt two. The left top plate, left bottom plate, left wedge plate one, and left wedge plate two are placed between spring steel plate one and spring steel plate two. The left sleeve has left tightening bolt holes one and two corresponding to the center points of left wedge plate one and left wedge plate two. Left tightening bolt one and left tightening bolt two are screwed into the tightening bolt holes, pressing left wedge plate one and left wedge plate two inward, so that the left top plate is tightened upward and the left bottom plate is tightened downward, thus securing spring steel plate one and spring steel plate two. The right tightening device includes a right top plate, a right bottom plate, a right wedge plate one, a right wedge plate two, a right tightening bolt one, and a right tightening bolt two. The relationship between the components is the same as that of the left tightening device. The contact surface between the spring steel plate one and the right top plate is provided with a PTFE plate, and the contact surface between the spring steel plate two and the right bottom plate is provided with a PTFE plate.

[0011] The beneficial effects of this invention are as follows:

[0012] This invention solves the problem of insufficient seismic toughness in slender, horizontally laced lattice columns designed with strong laced tubes. When designing horizontally laced lattice columns with strong laced tubes, a single-span multi-story frame model is used, with the column's midpoint being the inflection point. Under seismic loading, the lattice column fails after the column's base joints yield, resulting in insufficient seismic toughness. This invention fundamentally changes the design method based on strong laced tubes, abandoning the single-span multi-story frame model. It requires the laced tubes to be weaker than the column's base. In internal force analysis, the laced tubes are treated as a continuous medium. An equilibrium differential equation is established based on the vertical deformation compatibility condition at the laced tube's inflection point. The shear force distribution coefficient of the laced tubes is obtained by solving the equation. Based on the equilibrium condition that the total shear force of the laced tubes is equal to the axial force at the bottom of the column, the internal forces of the column and laced tubes under various level seismic loading are quantitatively analyzed. According to the seismic performance-based design method, the performance targets of the column members and ducts are correlated with the internal forces under various levels of seismic action. The bearing capacity and deformation capacity of the column members, energy dissipation ducts and self-resetting ducts are rationally designed to achieve the gradient failure mode of the lattice column under seismic action: the energy dissipation ducts yield and dissipate energy first, then the column members on the compression side yield, and finally the column members on the tension side yield, and the component fails. When the component fails, the self-resetting ducts still maintain elasticity, provide the component with the restoring force, and ensure that no single column member fails due to instability.

[0013] This invention incorporates a reset leaf spring assembly. The component exhibits minimal residual deformation under seismic cyclic loading, facilitating post-earthquake repair. Furthermore, the reset leaf spring assembly is simple to manufacture and cost-effective. The reset leaf spring assembly within the self-resetting duct can reset the plastic deformation of the energy-dissipating duct, reducing residual deformation and additional bending moments caused by vertical load eccentricity, thus facilitating post-earthquake structural repair. The reset force in the reset leaf spring assembly is provided by spring steel plates one and two, which are manufactured by cutting the factory-prepared spring steel plates to predetermined dimensions and drilling positioning bolt holes at both ends. Compared to self-resetting components such as springs, disc springs, SMA rods, and prestressed tendons, leaf springs are simpler to manufacture and more economical.

[0014] The reset leaf spring assembly of this invention is easy to install. The reset leaf spring assembly is located inside the sleeve. After the spring steel plates are inserted into the left and right sleeves, positioning screws are first installed at both ends to achieve vertical positioning. Then, the tightening device is positioned between spring steel plate one and spring steel plate two. Tightening bolts are screwed into the tightening bolt holes on both sides of the sleeve to press the spring steel plates tightly against the surrounding structure, achieving secure embedding at both ends of the spring steel plates, making installation convenient.

[0015] The functions of each component in this invention are clearly defined, and their corresponding performance objectives are clear, facilitating design and quality control. The column members in this invention primarily bear vertical loads. The energy-dissipating duct protects the column members by dissipating seismic energy through plastic deformation, while the self-resetting duct provides restoring force and stabilizes the column members. Corresponding to these functions, the performance objectives of each component are: the energy-dissipating duct yields during moderate earthquakes; during major earthquakes, the energy-dissipating duct dissipates seismic energy through plastic deformation; minor damage is permissible in the compression column members; the tension column members remain elastic; during extreme earthquakes, the compression column members are permissible to yield, the tension column members do not yield, and the self-resetting duct always remains elastic. The functions and performance objectives of each component are simple and clear, therefore the main control factors during design and manufacturing are clear, making design and manufacturing convenient. Attached Figure Description

[0016] Figure 1 A three-dimensional structural diagram of a self-resetting gradient seismic-resistant slender steel tube concrete lattice column provided in an embodiment of the present invention;

[0017] Figure 2 An elevation view of a self-resetting gradient seismic-resistant slender steel tube concrete lattice column provided for an embodiment of the present invention;

[0018] Figure 3 for Figure 2 Sectional view of section AA;

[0019] Figure 4 for Figure 3 Sectional view of section BB;

[0020] Figure 5 for Figure 3 Sectional view of the C-section;

[0021] Figure 6 This is a schematic diagram of the self-resetting steel-concrete composite pipe assembly of the present invention.

[0022] Figure 7 This is an exploded view of the self-resetting steel-concrete composite pipe resetting leaf spring assembly of the present invention.

[0023] Figure 8 This is an exploded view of the left tightening device for the self-resetting steel-concrete composite pipe fitting of the present invention.

[0024] In the diagram: 1. Steel-concrete composite column; 2. Energy-dissipating duct; 3. Self-resetting duct; 4. Left sleeve; 5. Right sleeve; 6. Resetting leaf spring assembly; 7. Metal flexible hose; 8. Spring steel plate one; 9. Spring steel plate two; 10. Left limiting bolt; 11. Upper left pad; 12. Lower left pad; 13. Left tightening device; 14. Left tightening bolt hole one; 15. Left tightening bolt hole two; 16. Right limiting bolt; 17. Upper right pad; 18. Lower right pad; 19. Right tightening device; 20. Right tightening bolt hole one; 21. Right tightening bolt hole two; 22. Top plate; 23. Bottom plate; 24. Wedge plate one; 25. Wedge plate two; 26. Tightening bolt one; 27. Tightening bolt two. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0026] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the disclosed technical content. Furthermore, the terms "upper," "lower," "left," "right," "one," and "two," etc., used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0027] The following is combined Figures 1 to 8 The present invention provides a self-resetting gradient seismic-resistant slender steel-concrete lattice column. In this embodiment, it includes a steel-concrete column member 1, an energy-dissipating duct 2, and a self-resetting duct 3. The energy-dissipating duct 2 and the self-resetting duct 3 are arranged alternately and uniformly layer by layer along the column height. The energy-dissipating duct 2 is made of high-ductility, low-yield-point steel pipe, and the self-resetting duct 3 is composed of a left sleeve 4, a right sleeve 5, a reset leaf spring assembly 6, and a metal flexible hose 7.

[0028] This invention requires that the stiffness of the ductwork be less than that of the column. In internal force analysis, the ductwork is treated as a continuous medium, with its midpoint as the inflection point. Based on the vertical deformation compatibility conditions at the inflection point, an equilibrium differential equation is established, and the shear force distribution coefficient of the ductwork in the elastic stage is obtained. The shear force distribution coefficients of the energy-dissipating ductwork 2 and the self-resetting ductwork 3 are proportional to their respective linear stiffness. This allows for quantitative analysis of the internal forces of the column and ductwork under various seismic loading levels. Following the seismic performance-based design method, performance targets for the column and ductwork are set: the energy-dissipating ductwork 2 begins to yield during moderate earthquakes and dissipates energy through yielding deformation during major earthquakes; the steel-concrete composite column 1 remains elastic during moderate earthquakes, maintains elasticity on the tension side during major earthquakes, and begins to yield on the compression side; the self-resetting ductwork 3 remains elastic throughout. Based on the performance targets of each component, the internal forces are selected, and the bearing capacity and deformation capacity of the steel-concrete composite column limb 1, energy dissipation duct 2, and self-resetting duct 3 are designed to achieve the gradient failure mode of the lattice column under seismic action: the energy dissipation duct 2 yields and dissipates energy first, then the column limb on the compression side yields, and finally the column limb on the tension side yields, and the component fails. At this time, the self-resetting duct 3 still maintains elasticity to ensure that a single column limb does not become unstable and fail.

[0029] Specifically, there are four steel-concrete composite column members 1. The steel pipes are made of high-strength steel and filled with high-strength self-compacting micro-expansion concrete. The column members are arranged compactly with a small clear distance. The energy-dissipating duct 2 has a circular steel pipe cross-section and is made of high-ductility, low-yield-point steel. It is connected to the column members by intersecting welds. Four ducts are arranged in a square shape on each floor and are evenly distributed along the height direction. The self-resetting duct 3 is arranged in the same way as the energy-dissipating ducts, and is spaced apart from the energy-dissipating ducts along the height direction. Under horizontal seismic loading, when the top of the lattice column shifts laterally, the energy-dissipating duct 2 yields first under the action of displacement deformation at both ends. The two ends of the self-resetting duct 3 are left and right sleeves 4 and 5, which are made of high-strength steel round pipes with a diameter close to that of the energy-dissipating duct 2. The connection method with the steel pipe concrete column 1 is through welding. A gap is left between the left and right sleeves 4 and 5 to allow for the installation of the reset leaf spring assembly 6. The gap is protected by a metal flexible hose 7. The two ends of the reset leaf spring assembly 6 are fixed inside the left and right sleeves 4 and 5. After the reset leaf spring assembly 6 is in place, the left and right sleeves 4 and 5 are then welded to the steel pipe concrete column 1.

[0030] Specifically, the reset leaf spring assembly 6 includes spring steel plate one 8, spring steel plate two 9, left limiting bolt 10, left upper pad 11, left lower pad 12, left tightening device 13, left tightening bolt hole one 14, left tightening bolt hole two 15, right limiting bolt 16, right upper pad 17, right lower pad 18, right tightening device 19, right tightening bolt hole one 20, and right tightening bolt hole two 21. Left upper pad 11 and left lower pad 12 are welded and fixed inside the left sleeve 4, and right upper pad 17 and right lower pad 18 are welded and fixed inside the right sleeve 5. Grooves are left on the straight edges of the four pads facing the center, with the groove width being the same as that of spring steel plate one 8 and spring steel plate two 9. Limiting bolt holes are drilled at both ends of spring steel plate 8 and spring steel plate 9. The upper surface of spring steel plate 8 is pressed against the groove of the left pad 11, and the lower surface of spring steel plate 9 is pressed against the groove of the left pad 12. Then, the left limiting bolt 10 is screwed in for vertical positioning. In the gap between spring steel plate 8 and spring steel plate 9, the left tightening device 13 and the right tightening device 19 are sequentially placed. The right sleeve 5 is then fitted from the right end, and the right limiting bolt 16 is screwed on, so that the upper surface of the right end of spring steel plate 8 is pressed against the groove of the right pad 17, and the right end of spring steel plate 9 is pressed against the groove of the right pad 18. The contact surfaces of spring steel plate 8, spring steel plate 29 with the right pad 17, right pad 18, and right tightening device 19 are covered with PTFE plates. With the tightening device in a relaxed state, adjust the above components left and right so that the distance between the two ends of the left and right sleeves 4 and 5 is the same as the clear distance of the steel pipe concrete column limb 1. Align the left tightening device 13 with the left upper pad 11 and the left lower pad 12 and tighten it with the left limit bolt 10. Align the right tightening device 19 with the right upper pad 17 and the right lower pad 18. Leave the right limit bolt 16 with the right upper pad 17 and the right lower pad 18 to allow the spring steel plates 8 and 9 to deform left and right as required.

[0031] Specifically, the left tightening device 13 includes a left top plate 22, a left bottom plate 23, a left wedge plate 1 24, a left wedge plate 25, a left tightening bolt 1 26, and a left tightening bolt 27. The width of the left top plate 22 and the left bottom plate 23 is the same as that of the spring steel plate 1 8 and the spring steel plate 2 9. The contact surface with the spring steel plate 1 8 and the spring steel plate 2 9 is a plane, and the back is a slope, with the slope being the same as that of the wedge plates 24 and 25. The left tightening device 13, from top to bottom, consists of a left top plate 22, left wedge plates 24 and 25, and a left bottom plate 23. It is placed in a relaxed state between spring steel plate 8 and spring steel plate 9, and aligned with the upper left pad 11 and lower left pad 12. Then, left tightening bolts 26 and 27 are simultaneously screwed into the left tightening bolt holes 14 and 15, pressing the left wedge plates 24 and 25 inwards. This causes the left top plate 22 to rise and the left bottom plate 23 to fall, thus securing the spring steel plates 8 and 9. The right tightening device 19 includes a right top plate, a right bottom plate 23, a right wedge plate, a right wedge plate, a right tightening bolt, and a right tightening bolt. The shape and installation order of each component are the same as those of the left tightening device 13.

[0032] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A self-resetting gradient seismic-resistant slender steel-tube concrete lattice column, characterized in that: The structure includes steel-concrete composite columns, energy-dissipating ducts, and self-resetting ducts. The energy-dissipating and self-resetting ducts are arranged alternately and uniformly layer by layer along the vertical direction of the lattice column. There are four steel-concrete composite columns, evenly arranged along the circumference, made of high-strength steel and filled with high-strength self-compacting micro-expansion concrete. The energy-dissipating ducts are circular steel pipes made of high-ductility, low-yield-point steel, evenly arranged along the height of the lattice column, with four ducts per layer forming a square. The self-resetting ducts are arranged along the height of the lattice column. The self-resetting tubes are evenly arranged in the direction of degrees. Each layer has four self-resetting tubes arranged in a square. The square includes a left sleeve, a right sleeve, a reset spring assembly that is fixed at both ends, and a metal flexible tube that protects the gap between the left and right sleeves. The reset spring assembly includes a spring steel plate one, a spring steel plate two, a left limiting bolt, a left upper pad, a left lower pad, a left tightening device, a left tightening bolt hole one, a left tightening bolt hole two, a right limiting bolt, a right upper pad, a right lower pad, a right tightening device, a right tightening bolt hole one, and a right tightening bolt hole two.

2. The self-resetting gradient seismic-resistant slender steel tube concrete lattice column according to claim 1, characterized in that: The end of each energy-dissipating duct is welded to the corresponding steel-concrete composite column; the left and right sleeves are both round steel pipes, which are welded to the corresponding steel-concrete composite column.

3. The self-resetting gradient seismic-resistant slender steel tube concrete lattice column according to claim 1, characterized in that: The left pad is welded to the upper part of the inner wall of the left sleeve, and the lower part of the left pad is welded to the lower part of the inner wall of the left sleeve. The right pad is welded to the upper part of the inner wall of the right sleeve, and the lower part of the right pad is welded to the lower part of the inner wall of the right sleeve. All four pads have grooves along their straight edges, with the groove width matching that of the spring steel plate. One spring steel plate has its left end attached to the lower surface of the groove on the left pad, and its right end attached to the lower surface of the groove on the right pad. The right end contact surface is provided with a PTFE plate. Another spring steel plate has its left end attached to the upper surface of the groove on the lower part of the left pad, and its right end attached to the lower surface of the groove on the right pad. The end is attached to the upper surface of the groove under the right pad, and the right end contact surface is provided with a PTFE plate; the left end of spring steel plate one and spring steel plate two has a limit bolt hole and a left limit bolt is provided, the end of which is attached to the left side of the left pad and the left pad under the left pad for positioning; the right end has a limit bolt hole and a right limit bolt is provided, the end of which leaves a sliding gap between the spring steel plate and the right side of the right pad and the right pad under the right pad; the left limit bolt and the right limit bolt pass through spring steel plate one and spring steel plate two in sequence to position them vertically.

4. A self-resetting gradient seismic-resistant slender steel tube concrete lattice column according to claim 3, characterized in that: The left tightening device includes a left top plate, a left bottom plate, a left wedge plate one, a left wedge plate two, a left tightening bolt one, and a left tightening bolt two. The left top plate, left bottom plate, left wedge plate one, and left wedge plate two are placed between spring steel plate one and spring steel plate two. The left sleeve has left tightening bolt holes one and two corresponding to the center points of left wedge plate one and left wedge plate two. Left tightening bolt one and left tightening bolt two are screwed into the tightening bolt holes, pressing left wedge plate one and left wedge plate two inward, so that the left top plate is tightened upward and the left bottom plate is tightened downward, thus securing spring steel plate one and spring steel plate two. The right tightening device includes a right top plate, a right bottom plate, a right wedge plate one, a right wedge plate two, a right tightening bolt one, and a right tightening bolt two. The relationship between the components is the same as that of the left tightening device. The contact surface between spring steel plate one and the right top plate is provided with PTFE plate, and the contact surface between spring steel plate two and the right bottom plate is provided with PTFE plate.

5. A self-resetting gradient seismic-resistant slender steel-tube concrete lattice column according to claim 4, characterized in that: After the spring steel plate of the reset leaf spring assembly is inserted into the left and right sleeves, positioning screws are first installed at both ends for positioning. Then, the clamping device is positioned between spring steel plate one and spring steel plate two. The clamping bolts are screwed into the clamping bolt holes on both sides of the sleeve, which can clamp the spring steel plate to the surrounding structure and realize the embedding of the two ends of the spring steel plate.

Images