Seismic Response Analysis Of Skew Girder Bridges With Lead-rubber Bearing

Due to its distinctive outer structure, skew bridge can better adapt themselves to terrain and environmental constraints, so that it has become so widespread. It shows a certain vulnerability under the action of earthquake, and the failure mechanism is relatively complex, which resulted from the comprehensive effect of a series of factors such as bending-torsion coupling, slope effect, in-plane crawl displacement effect, etc.Because of its great performance of seismic isolation and energy consumption, the lead-rubber bearing is considered to be the ideal device of seismic isolation and reduction of bridges. In this paper, seismic response of skew girder bridge with lead-rubber bearing under seismic action has been emphatically studied on the main contents are as follows:(1) The damping effect of the lead-rubber bearing is better than the plate ones, and the lead-rubber bearing has obvious shock absorption effect. The using of lead-rubber bearing can greatly reduce the shear and moment at pier bottom, the earthquake force will be redistributed reasonably, and pier stress into balance.(2) Based on seismic response analysis of simply-supported skew girder bridge with lead-rubber bearing under different ground motion input. The spatial coupling is characteristic of skew bridge rather than the orthogonal one. In other words, the internal forces in one and the orthogonal direction generated at the same time, as well as the generation of torque.(3) Under different direction of ground motion input, the internal force show different trends. When the ground motion input along X or Y alone, the shearing force at the end of the pier does not change with the angle of the simply-supported skew girder bridge. When the ground motion input along N alone, the shearing force Fx decreases with the increase of the angle, and Fy increases, when the ground motion input along T alone, the result is the opposite. When the ground motion input along X or N alone, the bending motion My decreases with the increase of the angle, and increases when input along Y or T. The changing rule of shearing force Fx basically the same with Fy in different ground motion input.When the ground motion input along XY or NT, the shearing force in time history analysis method increases after the first decreases with the increase of the angle of simply-supported skew girder bridge, while the moment of pier bottom shows a decreasing trend.(4) For single-span skew girder bridge, the internal forces increase with the increase of span.