高阶振型对高墩桥梁抗震性能的影响及其识别

针对墩高60m、90m 的典型高墩桥梁，运用增量动力分析方法（IDA）和基于基阶振型的非线性静力推倒方法（MPA）

Effect of higher modal shapes on aseismic performance of a bridge with high piers and its identification

For bridges with 60m、90m pier height,yield displacements,ultimate one,displacement ductility and curvature distribution of the critical state were determined with the incremental dynamic analysis(IDA) and pushover method considering the fundamental mode(MPA).After analyzing the results from IDA and MPA,the effect of higher modal shapes on pier ductility was evaluated under different earthquakes.Curvature distribution along piers under different earthquakes were described to reveal that under the action of strong earthquake plastic hinges are developed at the middle and the upper parts of pier except the base of pier.Capacity diagrams and demand diagrams were developed to identify the plastic level of higher mode respectively in different critical states,they were used to verify that the occurrence of plastic hinge at middle and upper parts of pier is attributed to the contribution of the second modal shape.