CN101260692B - Bearing force-free anti-knock steel support system - Google Patents

Abstract

The invention discloses a gravity-free anti-seismic steel support system. It is composed of multiple splayed oblique support units, which include steel columns, steel beams, steel oblique supports, steel beam corbels, bolts, steel thin gaskets, support corbels, support nodes, two steel The bottom of the diagonal support is connected with the lower end of the two steel columns and the intersection of the steel beam through the support node. The upper end of the two steel diagonal supports is provided with a support corbel, which is connected with the side of the steel beam corbel welded under the steel beam through bolts. The steel beam The bolt hole on the corbel is an elliptical hole whose vertical axis is the long axis. The two ends of the steel beam are connected with the upper end of the steel column through the support node, and a thin steel gasket is provided between the support corbel and the steel beam corbel. 100% of the bearing capacity and rigidity of the steel diagonal support in the invention are used to resist horizontal earthquake action, without affecting the construction progress of the project, and materials are obtained locally. It has the characteristics of good seismic performance, high ductility, and full energy dissipation hysteresis loop, and is a superior seismic energy dissipation component.

Description

Earthquake-free steel support system

technical field

The invention relates to the technical field of building structure engineering, in particular to a load-bearing-free anti-seismic steel support system.

Background technique

Steel diagonal braces are traditional steel structural members that enhance the lateral stiffness and lateral bearing capacity of single-story, multi-layer and high-rise steel structures. Steel diagonal braces are arranged in steel frame structures, which fundamentally changes the mechanism of lateral force Change: from steel frame beams and columns resisting lateral force, to a truss in which steel supports are used as diagonal web members, beams are used as horizontal web members, and columns are used as left and right chord members. moment, the horizontal component of the tension force of the diagonal bar resists the shear force of the lateral force. Because after the steel diagonal support is installed, the structure becomes an axial force and lateral force resistance system, and the stiffness increases by dozens of times, making the steel structure suitable for building taller buildings.

The purpose of setting up the steel oblique brace is to increase the lateral stiffness of the structure and increase the strength of the structure against lateral force. But unfortunately, because the two ends of the steel diagonal support are rigidly connected with the beam and column, when the column undergoes compression deformation under the action of vertical gravity load, the steel diagonal support also undergoes compression deformation, and the stress generated by the gravity load appears in the steel diagonal support , and this stress is not small. According to the deformation coordination calculation, the stress generated in the steel diagonal support often reaches 70% of the column stress. As a result, most of the rigidity and bearing capacity of the diagonal supports that should be used to resist lateral forces are consumed by vertical loads.

Other lateral force-resistant structures, such as shear walls with vertical joints, steel plate braced shear walls, steel plate shear walls, buckling-resistant braces, etc., have the same problem. Although the design code requires that these members do not bear vertical loads, the structure of the connection with the beams and columns determines that they must bear vertical forces.

In order to make the above-mentioned lateral force-resisting members used in conjunction with the steel structure bear the vertical load as small as possible, it is often required that these members turn back after the entire structure is installed to the top and most of the vertical loads have been transferred to the columns. Install these side force resistant members.

But like this, brought very big problem to construction: (1) the construction period of building has prolonged. (2) Since the column has been compressed, the length of the diagonal support and the size of the drawing have changed, and measures must be taken. Sometimes the length is measured on site before the components are made, so that the installation can be carried out smoothly. This further prolongs the construction period. (3) Since the floor slab has been poured at this time, workers are forced to construct without a tower crane, which is very inconvenient for heavy components to be displaced. For the above reasons, several kinds of lateral force-resistant members listed in the appendix of "Technical Regulations for Steel Structures of High-Rise Buildings" (JGJ98-99) are almost not used in China. The application of individual projects has also brought great controversy. The original design of Tianjin Jinta Project required steel plate shear walls to be fixed behind, but because of the construction period, it was changed to be fixed simultaneously with the columns, and the steel consumption increased a lot.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a bearing-free anti-seismic steel support system.

The gravity-free anti-seismic steel support system is composed of multiple splayed support units. The splayed support unit includes steel columns, steel beams, steel slant supports, steel beam corbels, bolts, steel thin gaskets, and support corbels. , Support node, the bottom of the two steel diagonal supports is connected with the lower end of the two steel columns and the intersection of the steel beam through the support node, the upper end of the two steel diagonal supports is provided with a support corbel, and the support corbel is connected with the steel beam cattle fixed on the steel beam The sides of the legs are connected by bolts, the two ends of the steel beam and the upper end of the steel column are connected at the support nodes, and a steel thin gasket is provided between the supporting corbel and the steel beam corbel, and the thickness of the steel thin gasket 6 is 1-5 mm.

The bolt connection holes of the supporting corbels, steel beam corbels and steel thin gaskets are vertical elliptical holes, the major axis of the elliptical hole is 1.5 to 2.5 times the minor axis, and the minor axis is 1 to 2.5 times larger than the diameter of the bolt rod. 3mm.

The gap between the support bracket 7 and the steel beam 2 is 30-70 mm, and the gap between the steel beam bracket 4 and the steel diagonal support 3 is 30-70 mm.

The superimposition of multiple figure-eight oblique support units is the superposition of multiple figure-eight oblique support units, the upside-down superposition of multiple figure-eight oblique support units, or the upside-down superposition of multiple figure-eight oblique support units at intervals. The present invention has the beneficial effect compared with prior art:

1) Because the steel support does not bear the vertical load and does not bear the pressure in advance, the degradation of the steel support performance during the earthquake is slowed down and delayed, and the seismic performance of the steel support structure system is significantly improved;

2) It will not affect the progress of the project at all.

At present, some lateral force-resisting components require that the entire structure be capped and all reinforced concrete floors be poured before the final lateral-force-resisting components can continue to be fixed. For example, the anti-buckling bracing system currently used in Japan. Because it affects the follow-up process (such as water and electricity equipment installation and building decoration), which has a great impact on the construction period of the building, which makes the owner reluctant to adopt it. After adopting the bearing-free steel support system of the present invention, the construction of each floor is carried out synchronously with the beams and columns, without any influence on the construction.

3) Local materials

Anti-buckling braces are made of steel with a low yield point, which is produced in small quantities, resulting in high prices. The load-free steel diagonal support adopts the same steel as the steel beam and steel column in the same project.

Description of drawings

Fig. 1 is a schematic diagram of the herringbone-shaped load-free anti-seismic steel support system of the present invention.

Fig. 2 is a schematic diagram of an inverted herringbone free load-bearing anti-seismic steel support system of the present invention.

Fig. 3 is a schematic diagram of the combined layout of herringbone and inverted herringbone load-free steel support systems of the present invention

Fig. 4 is an exploded view of the unit of the herringbone-shaped load-free anti-seismic steel support system of the present invention.

The components and elements indicated by the numbers marked in Figure 4 are accordingly: steel column 1, steel beam 2, steel diagonal support 3, steel beam corbel 4, bolt 5, steel thin gasket 6, support corbel 7, support node 8

Detailed ways

The gravity-free anti-seismic steel support system is composed of multiple splayed oblique support units, which include steel columns 1, steel beams 2, steel oblique supports 3, steel beam corbels 4, bolts 5, and thin steel pads Sheet 6, support corbel 7, support node 8, the bottom of the two steel diagonal supports 3 is connected with the intersection of the lower ends of the two steel columns 1 and the steel beam 2 via the support node 8, and the upper ends of the two steel diagonal supports 3 are provided with a support corbel 7 , the supporting corbel 7 is connected with the side of the steel beam corbel 4 fixed on the steel beam 2 through the bolt 5, the two ends of the steel beam 2 are connected with the upper end of the steel column 1 through the support node 8, the supporting corbel 7 is connected with the steel beam corbel A steel shim 6 is provided between the legs 4 . The thin steel gasket 6 has a thickness of 1-5mm.

The bolt connection holes of the supporting corbel 7, the steel beam corbel 4 and the thin steel gasket 6 are vertical elliptical holes, and the major axis of the elliptical hole is 1.5 to 2.5 times the minor axis. The minor axis is 1 to 3 mm larger than the diameter of the bolt shank.

The gap between the support bracket 7 and the steel beam 2 is 30-70 mm, and the gap between the steel beam bracket 4 and the steel diagonal support 3 is 30-70 mm.

The superimposition of multiple figure-eight oblique support units is the superposition of multiple figure-eight oblique support units, the upside-down superposition of multiple figure-eight oblique support units, or the upside-down superposition of multiple figure-eight oblique support units at intervals.

The present invention proposes the structure of connecting nodes through the beam and the support, so that the herringbone support vertically allows the steel beam to generate displacement, so that the vertical load will not be transmitted to the support, and the steel diagonal support does not participate in bearing the vertical load; the support and the steel beam They are in close contact with each other in the horizontal direction, and there is no horizontal relative slippage. When the steel frame moves sideways under the action of a horizontal earthquake, the support points also move horizontally, and the support participates in bearing the horizontal force, which plays an anti-seismic role.

The specific implementation of the gravity-free anti-seismic steel support system can be illustrated with reference to Figures 1 to 4:

1) Steel columns 1 and steel beams 2 form a steel frame, and the steel frame has low lateral stiffness, so steel diagonal supports 3 are added. The two oblique supports meet in the middle of the beam, as is done at present, without taking special measures, the support will appear as the middle support of the steel beam, and most of the vertical load on the steel beam will be transferred to the support. Now, in the present invention, the steel diagonal support is not directly connected with the steel beam, but a small section of I-shaped cross-section corbel is made upward after the two diagonal supports meet, and the I-shaped cross-section corbel extending downward from the steel beam is adopted sideways For bolt connection, the bolt holes are vertical elliptical holes in the supporting corbel or on the steel beam corbel, and the top of the corbel on the support is still 30mm to 70mm away from the lower surface of the beam, allowing the supporting corbel The legs and steel beam corbels can be staggered vertically, and the vertical load on the steel beam will not be transmitted to the support.

2) The installation steps of the load-free anti-seismic steel support are: (a) assume that the steel column and the lower steel beam have been installed; (b) start hoisting the assembled steel diagonal support, put it in place, correct it, temporarily fix it, and tighten it Bolts, partly welded; (c) Then hoist the upper steel girder, at this time the supporting corbel must be inserted between the two steel beam corbels or the steel beam corbel must be inserted between the two supporting corbels, so the corbel There needs to be a certain gap between them to facilitate installation, and the gap is 2mm to 5mm. (d) After the steel beam is in place, it is temporarily fixed with the steel column, then permanently fixed with high-strength bolts, and the beam-column joints are welded. (e) After the beam-column joints are completed, install the bolts between the supporting corbels and the steel beam corbels. For the convenience of installation, the gap between the corbels is filled with thin steel sheets of 1mm, 2mm, and 3mm until there is basically no gap , Make large bolt holes on the thin steel sheet to avoid easy installation.

3) The design method of the load-free anti-seismic steel support system is:

(a) According to the overall analysis of the structure, the two oblique supports bear tension and pressure respectively, and the supports are designed according to the buckling capacity under compression, the section is selected, and the slenderness ratio inside and outside the plane of the support and the width-to-thickness ratio and height-thickness of the composed plates are limited Compare.

(b) The choice of bolts is that, under the action of rare earthquakes, two supports, one in tension and one in compression, and the tension bar yields and the compression bar buckles, the bolts should be able to transmit the vertical force. force difference. Under normal circumstances, these bolts do not participate in force transmission, but transmit horizontal force by direct contact between the supporting corbel and the steel beam corbel.

(c) The size of the supporting corbel and steel beam corbel is required to be able to bear the resultant force of the horizontal component force of the full-section yield tension of the tension support and the buckling capacity of the compression support.

(d) Steel beams directly connected to supports shall be designed as compression-bending bars and shall be capable of bearing the vertical components of the tensile yielding and compressive buckling capacity. In order to keep the cross-sectional size of the steel beam at a reasonable level, the internal force is not enlarged when designing the support.

(e) The design of the steel column directly connected with the support requires that within the scope of the support frame itself, the strong column and the weak beam are still satisfied, and the axial pressure of the steel column should be in accordance with the compressive buckling force ratio of the weakest layer support under the design earthquake force The ratio of the pressure on the support is used to amplify the seismic force, and then combined with the axial force generated by the gravity load, the design is carried out according to the internal force of this combination, or the column is directly designed according to the elastic requirements of moderate earthquakes.

Claims (2)

1. A load-bearing-free anti-seismic steel support system is characterized in that it is formed by superimposing a plurality of figure-eight oblique support units, and the figure-eight oblique support units include steel columns (1), steel beams (2), steel oblique supports (3 ), steel beam corbels (4), bolts (5), steel thin gaskets (6), support corbels (7), support nodes (8), two steel diagonal supports (3) bottoms and two steel columns (1 ) and the intersection of the steel beam (2) are connected via the support node (8), and the upper end of the two steel diagonal supports (3) is provided with a support corbel (7), and the support corbel (7) is fixed on the steel beam (2 ) on the side of the steel beam corbel (4) is connected by bolts (5), the two ends of the steel beam (2) and the upper end of the steel column (1) are connected at the support node (8), and the support corbel (7) is connected to the steel Steel thin gaskets (6) are arranged between the beam corbels (4); the bolt connection holes of the support corbels (7), steel beam corbels (4) and steel thin gaskets (6) are vertical An elliptical hole, the major axis of the elliptical hole is 1.5 to 2.5 times the minor axis, and the minor axis is 1 to 3 mm larger than the diameter of the bolt bolt; the thickness of the thin steel gasket (6) is 1 to 5 mm; The gap between the leg (7) and the steel beam (2) is 30-70 mm, and the gap between the steel beam corbel (4) and the steel diagonal support (3) is 30-70 mm. 2. A load-free anti-seismic steel support system according to claim 1, characterized in that the superimposition of said plurality of figure-eight oblique support units is the superposition of a plurality of figure-eight oblique support units, a plurality of figure-eight oblique support units Inverted stacking or multiple splayed oblique support units are stacked upside down at intervals.

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