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| Seismic Design of the Continuous Rigid Frame Bridge with Double Thin-walled Short Piers in High Intensity Earthquake Area |
| ZHANG Yong-liang，LU Xiao-su，CHEN Xing-chong，WANG Yun |
| （Lanzhou Jiaotong University，Lanzhou，Gansu 730070 ，China) |
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Abstract Abstract：Research purposes： Taking the continuous rigid frame bridge with double thin-walled short solid piers in high intensity earthquake area as the research object, and focusing on the overall seismic performance of the substructure, a selection method of ductility seismic system for the pier of this kind of the bridge is presented based on the three level fortification target. The relationship between section size, longitudinal reinforcement ratio and structural seismic performance of double thin-wall short piers is systematically discussed. Research conclusions： (1) For the double thin-wall short piers of the continuous rigid frame bridge in high intensity earthquake area, the failure modes should be judged according to the shear span ratio of piers, and then the seismic ductility classification and design method are also chosen. (2) Under the excitation of low-level earthquakes, the section size and reinforcement design of main pier are controlled by the longitudinal seismic response of the bridge, the longitudinal bending moment of the critical section of main piers is obviously increased with the increase of wall thickness, and the amplitude of increase was greater than that of transverse excitation. (3) Under transverse high-level earthquake excitation, only the perfectly elastic or basic elastic structure could be adopted because the shear span ratio of the pier in the transverse direction was relatively small. This will cause the fact that the reinforcement ratio of the pier and the pile foundation is significantly increased, so it became the main factor to control the design of the substructure. (4) Under the longitudinal high-level earthquake excitation, the demand of plastic rotation of main piers decreases when wall thickness increases, under the three combinations of wall thickness and longitudinal reinforcement ratio, the plastic rotation capacity of the plastic hinge achieves the seismic fortification target of "No Collapsing in the Strong Earthquake", and its deformation capacity and safety reserve is basically equal. (5) The research results can provide a reference for the seismic design of similar bridges.
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Received: 01 September 2017
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2017, Vol. 34 
