Study On Seismic Time-history Response Of Curved Multi-span Continuous Rigid Frame Bridges With High-pier

Western region of China is a mountainous zone, with high mountains and deepgorges, complex terrain. Along with the increasing of the pier height and the span, thecurved continuous rigid frame bridge gradually becomes the main bridge across themountainous rivers and the deep canyons, because it can overcome the influence ofthe landform and physiognomy effectively. Based on the Baishuiyu Bridge of Sanxiexpressway, the thesis carries on the dynamic analysis of the curved multi-spancontinuous rigid frame bridges with high-pier. The main research contents andconclusions are as follows：（1）The theory and method of dynamic analysis to the curved multi-spancontinuous rigid frame bridges with high-pier are summarized in this paper, as well asthe research status at home and abroad.（2）The influence of structural free vibration characteristics on the curvedmulti-span continuous rigid frame bridges with high-pier is researched in differentcurvature radius and pier heights. The results show that the modal of fundamentalfrequency is the longitudinal wave of the girder and pier. The natural frequency of thefirst-order longitudinal wave increases with the increase of curvature radius. To thefirst transverse bending and the first to the fourth order vertical bending, the naturalvibration frequency decreases with the increase of pier height and curvature radius.（3）The most adverse direction of incentives is researched by the method ofdynamic time history analysis when the seismic wave of different angles is incented.The most adverse direction of incentives is the secant between the top of pier which isthe closest to the mid-span and the support of girder boundary and the perpendicularof this secant when the seismic wave is incented in the transverse and longitudinaldirection.（4）The sensitivity of curvature radius and pier height on the response ofstructure is studied when the seismic wave is incented in the most adverse direction.The results show that the lateral displacement of mid-span and the internal force of side pier increase with the increase of curvature radius and pier height when theseismic wave is incented in the transverse direction. With the increase of curvatureradius the internal force of3#pier increases inconspicuously. When the seismic waveis incented in the longitudinal direction the longitudinal displacement of mid-span issmall and the internal force of pier increases with the increase of pier height, butdecrease with the increase of curvature radius.