Longspan cable-stayed bridge aseismic structure provided with buckling restrained braces

Abstract

A longspan cable-stayed bridge aseismic structure provided with buckling restrained braces is characterized in that the paired buckling restrained braces are installed between the bottom surface of a girder and a lower cross beam of a bridge tower symmetrical about the center line of a bridge floor, one end of each buckling restrained brace is connected to the bottom surface of the girder, and the other end of each buckling restrained brace is connected to the top face or side face of the cross beam; the buckling restrained braces can also be symmetrically and transversely installed between the bottom surface of the girder and the lower cross beam of the bridge tower; longitudinal installation of the buckling restrained braces and transverse installation of the buckling restrained braces can be combined; the buckling restrained braces can also be used in cooperation with liquid dampers; under normal conditions, the proper rigidity of the buckling restrained braces can make a longspan bridge almost achieve consolidation with tower girder and pier or a support system have a sound anti-wind load; in a strong earthquake, yielding energy dissipation of the buckling restrained braces occurs, a tower and girder is nearly in a floating or semi-floating working state, earthquake load is reduced, and displacement response of the girder is controlled through energy dissipation hysteresis. The structure can be used for aseismic design of a newly built longspan cable-stayed bridge or aseismic reinforcement of an existing longspan cable-stayed bridge, and can also provide reference for building of a suspension bridge.

Description

technical field [0001] The invention relates to the field of road and bridge construction. Background technique [0002] Long-span cable-stayed bridges can be divided into structural systems: tower-beam pier consolidation system, support system (including semi-floating system), floating and tower-beam consolidation system. Evaluation on the effects of earthquake, wind and temperature loads: tower-beam pier consolidation system: high rigidity, good wind resistance, large temperature load, weak earthquake resistance; tower-beam consolidation system: moderate stiffness, good wind resistance, temperature load Controllable, the seismic capacity is still insufficient; floating and semi-floating systems: less rigidity, poor wind resistance, less temperature load, good seismic performance. [0003] In strong earthquake areas, when earthquake resistance becomes an important consideration, floating and semi-floating systems are still mostly used in long-span cable-stayed bridges. Bec...

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Problems solved by technology

[0003] In strong earthquake areas, when earthquake resistance becomes an important consideration, floating and semi-floating systems are still mostly used in long-span cable-stayed bridges. Because the overall stiffness is relatively soft, under the action of strong longitudinal earthquakes, the main girder will have a large longitudinal displacement, which will Cause the collision between the main beam end of the main bridge of the cable-stayed bridge and the main beam of the approach bridge, or the collision between the beam body and the abutment, and cause damage to other components such as expansion joints and supports, and excessive displacement of the main beam will also cause Large tower root bending moment and tower top displacement. Therefore, the floating system or semi-floating system cable-stayed bridges are usually equipped with longitudinal energy-dissipating shock-absorbing devices to reduce the longitudinal displacement of the main beam caused by earthquakes. At present, the most common one is viscous Dampers, but there are weaknesses in high technical complexity, weak reliability, oil leakage and high maintenance costs

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