半整体式桥台无缝化斜交桥的抗震性能分析

为了掌握半整体无缝斜交桥的动力特性和地震响应特点，采用MIDAS/Civil建立了湖州贯边桥的有限元模型，进行了动力特性分析，并运用反应谱法和地震时程法对无缝化斜交桥进行了地震响应分析。结果表明:梁端台后土对桥梁的约束作用随斜交角的增大而逐渐减弱；主梁梁端台后土的作用对桥梁结构是有利的，可以有效约束桥梁纵飘；在进行地震安全性分析时，用反应谱法所得的墩底内力和墩顶位移均大于时程分析法；在进行半整体无缝斜交桥的工程设计时，应以垂直于盖梁方向输入地震动计算固定支座所产生的墩顶位移来控制桥梁的抗震安全性；所得研究成果为半整体式桥台无缝化斜交桥的抗震设计和研究提供了可参考资料，对该桥型的实际工程应用和发展起到了推动作用。

Analysis on Seismic Performance of Semi-integral Abutment Jointless Skew Bridge

In order to grasp the features of vibration and seismic response of semi-integral jointless skew bridge, a finite element model of Huzhou Guanbian bridge was established with MIDAS/Civil. The dynamic characteristic analysis was carried out, and the response spectra method and time history were conducted to analyze the seismic response of semi-integral jointless skew bridge. The results show that the constraining effect of soil behind the abutment is weakened gradually with the decrease of skew angle of bridge. The effect of soil behind abutment is benefit to semi-integral abutment jointless skew bridge, which can restrict its longitudinal float effectively. The internal force of pier bottom and displacement of pier top calculated with response spectra method are even larger than those with time history analysis method during seismic safety analysis. The seismic safety of the type of bridge should be governed by the displacement of pier top caused by the fixed bearing while inputting the earthquake motion perpendicular to cap. The study results provide references data for the seismic design and research of semi-integral jointless skew bridge and promote the development and actual engineering application of the semi-integral jointless skew bridge.