CN101372843A - Friction type limited rocking shock absorber - Google Patents

Abstract

The invention belongs to the structural engineering technical field, particularly to a friction-type limitation tilting shock absorption post. The upper and the lower posts of a device are in splicing connection; posts are connected with a splice plate through a high strength bolt, and a ribbed stiffener is arranged on the splice plate on the outer side of a section steel post flange; the section steel post provides vertical bearing force and restoring force, so that the sliding generated by the friction force between the section steel post and the splice plate can be overcome to enable the upper structure to tilt; the arrangement of an oblong hole stops the structure from tilting, thereby enabling the side displacement of the structure not to be too large and preventing the structure from tilting; and the friction between the section steel post and the splice plate can dissipate the earthquake energy, and a friction sheet can increase friction effect and transfer the vertical force through the friction when the posts are fixed. The invention has the advantages of structure side-displacement limitation, small residual deformation, good shock resistance performance, ductility, hysteretic energy consumption capacity, convenient installation and replacement, installations on different floors, and realization of tilting of local floors. Therefore, the shock absorption post is an excellent structural member with shock resistance and energy consumption.

Description

Friction type limited rocking shock absorber

technical field

The invention belongs to the technical field of structural engineering, and in particular relates to a friction type limited rocking damping column.

Background technique

Rocking shock absorption is a novel shock absorption design concept. In the traditional concept of seismic design, the upper structure is fastened to the lower foundation, and the structure cannot be tilted up and down to loosen the lower foundation. The seismic force is mainly resisted by lateral force-resistant components (supports, shear walls, etc.). The traditional seismic isolation technology is to reduce the energy input of the earthquake to the upper floors by installing a seismic isolation device with a small lateral stiffness but a large deformation capacity in a certain floor of the building, thereby reducing the seismic response of the upper floors.

The seismic response of the rocking structure is basically the same as that of the conventional structure in the case of small and moderate earthquakes. In the case of a large earthquake, the rocking shock absorption technology allows the upper part of the structure to be separated from the foundation, and uses the lifting of the upper part of the structure to dissipate the seismic energy, and can block the transmission of strong earthquakes in the upper structure to ensure that the upper structure is elastic, thereby It can greatly reduce the redundancy of the lateral force-resisting components of the upper structure and the upper structural components, which can save materials and reduce manufacturing costs. On the other hand, the detachment of the structure and the foundation prevents the side columns and walls of the structure from generating vertical pullout force, thereby preventing serious damage to the foundation and the underlying structure in the event of a major earthquake, and can simplify the foundation structure and save foundation costs , the economic benefit is obvious.

The main deficiency of the existing rocking structure is that there is no reasonable rocking support. The energy dissipation capacity of the existing rocking support is weak, and there is no limit to the amplitude of the rocking motion. In the event of a large earthquake, the overall energy dissipation capacity of the structure is insufficient, and the lifting of the upper part of the rocking structure will cause the structure to move sideways. When moved too large, the structure as a whole will overturn.

Contents of the invention

The object of the present invention is to provide a friction-type limited rocking shock-absorbing column, which has the performance and advantages of the traditional rocking shock-absorbing structure, that is, the seismic response of the conventional structure is the same under medium and small earthquakes, and the superstructure and foundation are allowed to Generate relative displacement, dissipate seismic energy, and have self-recovery properties and so on. At the same time, it mainly overcomes two deficiencies existing in the existing rocking support, that is, after the support is lifted, the structure moves too far so that the overall structure overturns and the support has weak energy dissipation capacity. In addition, the impact effect when the support falls back, and the large residual deformation after the support is lifted have also been well resolved.

The friction-type limited rocking damping column proposed by the present invention is composed of the upper column 1 of the H-shaped steel column, the lower column 2 of the H-shaped steel column, the splicing plate 3 and the stiffener 4, wherein the flange of the lower part of the upper column 1 of the H-shaped steel column and The web plate is axially symmetrically provided with oblong holes 7, the flange of the upper part of the H-shaped steel column lower column 2 and the web plate are axially symmetrically provided with oblong circular holes 7, and the lower part of the H-shaped steel column upper column 1 is connected with the H-shaped steel column lower part. The upper part of the column 2 is connected by the splicing plate 3, and the high-strength bolt 5 passes through the oblong hole 7 in the lower part of the upper column 1 of the H-shaped steel column to connect with the splicing plate 3, and the connection between the lower part of the upper column 1 of the H-shaped steel column and the splicing plate 3 is provided with friction Plate 8 and high-strength bolt 5 pass through the oblong hole 7 on the upper part of the lower column 2 of the H-shaped steel column to connect with the splicing plate 3, and the joint between the upper part of the lower column 2 of the H-shaped steel column and the splicing plate 3 is provided with a friction plate 8, and the stiffeners 4 are respectively It is located on the splicing plate 3 outside the flange of the upper column 1 of the H-shaped steel column and the outer side of the flange of the lower column 2 of the H-shaped steel column.

In the present invention, the height ratio of the upper column 1 of the H-shaped steel column to the lower column 2 of the H-shaped steel column is 2:1.

In the present invention, the friction plate 8 is any one of copper, asbestos or rubber.

In the present invention, a rubber pad is provided between the upper column 1 of the H-shaped steel column and the lower column 2 of the H-shaped steel column. The section size of the rubber pad is the same as that of the section steel column. The rubber pad is close to the top of the lower column 2 of the H-shaped steel column.

In the present invention, the steel frame shaped steel column is divided into two parts, the upper column and the lower column, which are spliced by splicing plates at a height of about 1/3 storey away from the bottom of the column, and the shaped steel column bears the vertical load. Open oblong holes symmetrically on the column flange and web near the connection between the upper and lower parts of the steel column. A friction plate (copper sheet, asbestos, rubber, etc. can be used) is sandwiched between the steel column and the splicing plate, which can transmit vertical force through friction. The steel column and the splicing plate are connected by high-strength bolts. Under normal use conditions or under small and medium earthquakes, the columns formed by this structure are the same as ordinary steel columns, providing sufficient bearing capacity and rigidity for the structure. However, under the action of a large earthquake, the friction force between the steel column and the splicing plate is overcome, and the steel column slides relative to the splicing plate, thereby causing the whole structure to sway; due to the limited length of the oblong hole, the distance between the steel column and the splicing plate The relative sliding between them will be limited, so the lateral movement of the structure will be limited, and the structure will not overturn due to excessive lateral movement; the seismic energy can be effectively dissipated through the friction between the steel columns, friction plates and splicing plates, so that The whole column achieves the purpose of limiting rocking and shock absorption.

The friction-type limited rocking shock-absorbing column is spliced by upper and lower two-part steel columns, and the upper and lower two-part steel columns are called upper column and lower column respectively. The steel columns, friction discs and splicing plates are connected by high-strength bolts, which have sufficient fastening force to each other. Under normal use conditions, the vertical force is not enough to overcome the maximum static friction between the above three, and the main structure is in an elastic state. Therefore, the column bears the same load as ordinary steel columns and provides sufficient rigidity for the structure. When a large earthquake occurs, the horizontal seismic force causes each column to generate a large vertical tension and pressure, thereby overcoming the friction force at the joint and sliding, and the overall structure presents a rocking effect. After the structure rocks, once the friction joint starts to slide, its stiffness becomes zero, which softens the structure stiffness and prolongs the natural vibration period of the structure. Therefore, the natural frequency and basic mode shape of the original structure are changed during the sliding process, the amplitude of the structure is reduced, the resonance or quasi-resonance effect of the structure is avoided, and serious damage to the structure is further avoided.

Under normal use conditions, high-strength bolts are fastened to the bottom ends of the oblong holes of the upper and lower columns to connect the steel columns, friction discs and splicing plates. At this time, the vertical force of the column at the joint mainly depends on the friction between the friction plate and the steel column, and between the friction plate and the splicing plate. Due to the pre-tensioning force applied to the high-strength bolts in advance, the contact surfaces are sufficiently tightened after connection to provide strong friction for the friction surfaces. At this time, the high-strength bolts do not bear the shear force, so it is beneficial to the high-strength bolts. When the structure rocks, the upper column of the tension side steel column moves upward, and the oblong hole on it moves upward relative to the high-strength bolts in the hole. The high-strength bolt is initially located at the bottom of the oblong hole. Due to the relative movement trend, the bolt is sheared, which drives the splice plate to move upward, thereby driving the high-strength bolt at the lower end of the splice plate to slide upward in the oblong hole of the lower column. The lower column is fixed on the base plate. During the upward movement, there is no relative displacement between the oblong hole of the upper column and the high-strength bolt, and the high-strength bolt is always at the bottom of the oblong hole; the lower column is fixed, and the high-strength bolt slides upward in the oblong hole. Due to the limited length of the oblong hole, when the bolt in the oblong hole of the lower column slides to the top of the oblong hole, the sliding is restricted, and the bolt together with the splicing plate cannot continue to slide upward, so that the upper column cannot continue to slide upward, and the tilting of the structure is restricted. Shift will no longer increase. When the structure rocks, the upper column of the steel column on the compression side moves downward, and the oblong hole on it moves downward relative to the high-strength bolts in the hole. Due to the sliding friction between the steel column and the splicing plate, the splicing plate also has a tendency to move downward. The high-strength bolts are initially located at the bottom of the oblong holes, and the bolts located in the oblong holes of the lower column cannot move downward. Therefore, during the downward movement, the splicing plate, the high-strength bolts and the lower column are fixed, and the upper column moves downward. Also limited by the length of the hole, when the top of the upper column oblong hole slides to the bolt, the upper column cannot continue to slide downward. When the upper column slides downward, in order to prevent its impact on the lower column, a rubber material can be interposed between the upper and lower column sections to play a buffer role; at the same time, it can also reduce the impact of the bolts in the upper column and the hole wall . The effective sliding length of the oblong hole is about 3cm, and the side shift of the structure caused by the sliding meets the limit value of the side shift, and the structure will not overturn. Therefore, this shock-absorbing structure can achieve the purpose of limiting position, that is, limited rocking.

When the wall of the oblong hole on the shaped steel column is in contact with the high-strength bolt and squeezed, the bolt is subjected to punching and shearing force. Since the connection has a large enough friction area to share part of the shear force on the bolts, setting high-strength bolts with larger strength and larger bolt diameters can ensure their shear resistance. In terms of shear bearing capacity, since splicing plates are arranged on both sides of the steel column flange and web, the shear sectional area is increased and the shear bearing capacity is also enhanced. On the flange and web of the shaped steel column, since the diameter of the oblong hole is not very large, the section weakening is not much, and sufficient shear resistance can still be provided. Stiffeners are set on the splice plate outside the flange to ensure the bending resistance of the column at the splice.

After the structure rocks, the seismic energy can be dissipated through the friction between the steel column and the splicing plate, and the friction plate interposed between the two increases the frictional energy dissipation capacity of the structure. Therefore, compared with the traditional rocking shock absorption structure, in addition to the overall rocking shock absorption of the structure, a considerable part of the seismic input energy can be dissipated through frictional energy dissipation, and the overall energy dissipation capacity of the structure is greatly increased.

In a word, the present invention allows rocking to occur without a significant decrease in the axial, shear and bending bearing capacity, dissipates energy through friction and provides stable hysteretic energy dissipation performance, which limits the lateral movement of the structure and To prevent the structure from overturning; at the same time, the rocking part is moved from the support to the column. The column can be assembled in advance, which is convenient for installation. The rocking of the floors, and the easy replacement after the earthquake, is a promising rocking member form. In this kind of rocking member, the oblong hole not only allows the structure to rock, but also plays a role in restricting the lateral movement of the structure, and at the same time mainly dissipates energy through friction, so it is called a friction-type limited rocking shock-absorbing column.

In the present invention, oblong holes are provided on the flanges and the webs at the joints of the steel columns. In order to prevent the relative rotation of the column in the plane, two oblong holes are symmetrically opened along the axis of each flange and web. In order to prevent the steel plate at the end of the oblong hole from being sheared, the distance between the bottom of the hole (top of the hole) and the edge of the column section should not be less than 4 times the hole diameter.

In the present invention, splicing plates with the same strength as the columns and friction plates are provided on both sides of the flange and the web at the joints of the steel columns.

In the present invention, stiffening ribs are arranged on the splice plate outside the flange of the shaped steel column.

In the present invention, the high-strength bolts are fixed on the splicing plate and located at the bottom of the oblong holes of the upper and lower columns.

In the present invention, a rubber pad is arranged between the upper column and the lower column. The rubber pad is about 3cm thick, and the section size is the same as that of the steel column. The rubber pad is close to the top of the lower column, leaving a certain distance from the bottom of the upper column. This distance is equal to or slightly smaller than the absolute sliding length of the bolt in the oblong hole, about 3cm.

In the present invention, the shaped steel column is welded with the shoe beam and the bottom plate. Partitions are set between the shoe beams, and both the shoe beams and the partitions are welded to the bottom plate. The bottom plate is connected to the foundation with anchor bolts.

In the present invention, when the oblong hole of the shaped steel column slides vertically, due to the blocking of the bolt (essentially, the length of the oblong hole is limited), it no longer continues to slide upwards or downwards, limiting the lateral movement of the top floor of the structure. The double-shear friction connection is set at the flange and web of the steel column. For a given high-strength bolt pretension and friction material, the friction force of the friction connection double-shear is twice that of single-shear. Under repeated load, the friction element is not only under tension, but also under compression. When under pressure, the pressure of the single shear friction element is not in a straight line, forming a force couple, which is easy to cause warping or lateral instability. The force is symmetrical during double shearing, and the flange and web of the steel column are constrained by the splice plates on both sides, which is not easy to cause lateral warping or instability. Warpage during tension and compression can lead to unstable performance of friction elements. The performance of the energy dissipator composed of double-shear friction connection is relatively stable, and the friction force does not have large fluctuations. In order to increase the energy dissipation capacity and ensure the balance and stability of the friction and sliding force, sandblasting is performed on the friction contact surface. As the number of cycles increases, the friction force at the joints tends to decrease, mainly due to the wear of the friction surfaces. When the surface of the friction plate slides relative to each other, the adhesion node formed by the adhesion effect will shear and fracture, and the sheared material will either fall off as wear debris, or migrate from one surface to another surface, making the friction surface smooth and making the friction surface smoother. The friction coefficient is reduced, and at the same time, the wear of the friction surface will also cause the loss of pre-tension in the high-strength bolts and reduce the normal pressure, resulting in a reduction in frictional resistance. Experimental studies have shown that frictional energy dissipators equipped with copper plate friction plates have no significant decrease in frictional resistance as the number of cycles increases. Therefore, it is suggested in the present invention to select and install copper plate friction discs. Bolt holes and long grooves should be finished as much as possible to make them closely fit with high-strength bolts. There is a gap between high-strength bolts and bolt holes, which will cause relative slippage, so that the hysteresis curve loses Coulomb characteristics, and the edges of long hole grooves are not smooth. It will cause the high-strength bolts to get stuck and cause the friction to jump. If the connection between the friction element and the connecting rod or support is not tight, the performance of the friction element will not be fully utilized. The bolt hole can be finished with a reamer, so that the diameter of the bolt hole is only 0.2-0.3mm larger than the diameter of the screw rod. High-strength bolts should use refined bolts.

In the present invention, the shaped steel column rocks vertically. Due to the limitation of the length of the oblong hole, the shaped steel column cannot continue to slide upwards or downwards, which limits the lateral movement of the top floor of the structure and prevents the structure from overturning due to excessive lateral movement. Under the action of moderate or large earthquakes (determined according to the design), the steel column will slide according to the predetermined sliding load before the main structural members yield, which provides a mechanism for dissipating energy by friction. To bear a fixed load, that is, the friction force between the contact surfaces remains unchanged, and the rest of the load is still borne by the structure, and the internal force of the structure will be effectively redistributed. After the rocking occurs, the upper structure and the foundation are separated, and the tension in the lifting column is limited to the sliding friction level of the contact surface, so that the tension in the column is significantly reduced, which reduces the burden on the foundation; due to the tension of the column Reduced, on the other side of the rocking movement, the pressure in the column is also reduced correspondingly, which also reduces the burden on the foundation, prevents serious damage to the foundation and the bottom column, ensures structural safety, and reduces base cost.

The invention eliminates the disadvantages of the existing rocking support and improves the ductility of the structure. This component is essentially an energy-dissipating and shock-absorbing component, which dissipates seismic energy through friction generated by energy-dissipating connections to reduce the size of the main structure. The seismic response can limit the rocking range of the structure while consuming energy, thereby limiting the lateral movement of the structure, avoiding the damage or collapse of the upper structure, and achieving the purpose of shock absorption control.

The friction-type limited rocking damping column provided by the present invention is a new type of rocking damping member, which can effectively absorb shocks, provide stable hysteretic energy consumption performance, avoid superstructure and foundation damage, and effectively It greatly reduces the cost of the upper structure and the lower foundation, and is a promising form of rocking components.

Description of drawings

Fig. 1 is an overall schematic diagram of the friction-type limited rocking vibration damping column of the present invention.

Fig. 2 is a schematic diagram of the installation of the friction-type limited rocking vibration damping column of the present invention.

Fig. 3 is a schematic diagram of the front elevation of the friction type limited rocking vibration damping column of the present invention.

Fig. 4 is a side elevation schematic view of the friction type limited rocking shock absorbing column of the present invention.

Fig. 5 is a schematic cross-sectional view of the friction-type limited rocking vibration damping column of the present invention.

Numbers in the figure: 1 is the upper column of the H-shaped steel column, 2 is the lower column of the H-shaped steel column, 3 is the splice plate, 4 is the stiffener, 5 is the high-strength bolt, 6 is the rubber pad, 7 is the oblong hole, and 8 is the friction plate.

Detailed ways

The present invention is described in detail below in conjunction with accompanying drawing:

As shown in Figures 1, 2, 3, 4, and 5, the friction-type limited rocking damping column in the present invention consists of an upper column 1 of an H-shaped steel column, a lower column 2 of an H-shaped steel column, a splicing plate 3, a stiffener 4, a high-strength Composed of bolts 5, rubber pads 6 and friction plates 8; the upper column 1 of the H-shaped steel column is symmetrically provided with two oblong holes 7 along the axis of each flange and web, and correspondingly, the lower column 2 of the H-shaped steel column is The axes of the flange and the web are symmetrically provided with two oblong holes 7. The distance between the bottom of the oblong holes 7 and the section edge of the upper column 1 or lower column 2 should not be less than 4 times the aperture. The oblong holes 7 can be reserved in the factory . The upper column 1 of the H-shaped steel column and the lower column 2 of the H-shaped steel column can be spliced in advance in the factory. When splicing, the friction plate 8 is fixed on the lower part of the upper column 1 of the H-shaped steel column and the upper part of the lower column 2 of the II-shaped steel column with glue in advance. The lower column 2 is connected, and the high-strength bolt 5 is fixed on the splicing plate 3, which is located at the inner bottom of the oblong hole 7. During construction, the H-shaped steel columns spliced in the factory can be directly connected to the foundation and beams.

Claims (4)

1. friction type finite sway shock absorber strut, by H steel column upper prop (1), H steel column lower prop (2), scab (3), stiffening rib (4) is formed, it is characterized in that on the edge of a wing of H steel column upper prop (1) bottom and the web that symmetry offers slotted hole (7) vertically, on the edge of a wing on H steel column lower prop (2) top and the web vertically symmetry offer slotted hole (7), the bottom of H steel column upper prop (1) is connected by scab (3) with the top of H steel column lower prop (2), the slotted hole (7) that high-strength bolt (5) passes the top of H steel column lower prop (1) is connected with scab (3), the bottom of H steel column upper prop (1) and scab (3) junction are provided with friction plate (8), the slotted hole (7) that high-strength bolt (5) passes the bottom of H steel column upper prop (1) is connected with scab (3), the top of H steel column lower prop (2) and scab (3) junction are provided with friction plate (8), and stiffening rib (4) lays respectively on the scab (3) in the outside, H steel column upper prop (1) edge of a wing and the outside, H steel column lower prop (2) edge of a wing.

2. friction type finite sway shock absorber strut according to claim 1 is characterized in that the H steel column upper prop (1) and the aspect ratio of H steel column lower prop (2) are 2:1.

3. friction type finite sway shock absorber strut according to claim 1 is characterized in that described friction plate (8) selects in copper sheet, asbestos or the rubber any for use.

4. friction type finite sway shock absorber strut according to claim 1, it is characterized in that being provided with rubber pad between H steel column upper prop (1) and the H steel column lower prop (2), the rubber pad cross-sectional sizes is identical with the steel column cross section, and rubber pad is close to H steel column lower prop (2) top.

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