超大跨度斜拉桥随机地震响应参数敏感性分析

Analysis on Sensitivity of Stochastic Seismic Response Parameters of Super-long-span Cable-stayed Bridges

斜拉桥跨度的增大,使得地震动空间效应对结构地震反应的影响成为新的研究课题之一。本文基于随机振动理论,以苏通长江公路大桥为背景,对超大跨度斜拉桥在随机地震荷载作用下的动力响应展开研究。通过系统分析结构弹性模量(钢箱梁和索塔)、桩-土-结构动力相互作用、地震动模型、斜拉索振动效应以及模态组合数量对结构内力和位移的影响及其变化规律,掌握参数变化时,结构随机地震响应的变化范围是否可能因结构参数的变化而危及结构安全,为超大跨度桥梁的抗震设计和分析提供借鉴。

Based on the stochastic vibration theory and combined with the background of the Sutong Yangtze River Highway Bridge , the stochastic seismic responses of the super-long-span cable-stayed bridge were stud-ied .By stochastic and systematic analysis , the influence of the structural elastic modulus （steel box girders and towers） , pile-soil-structure interaction , seismic ground motion models , the cable vibration effect and the number and nature of modes on structural internal forces and displacements and its changing law were studied . The aim of study was to master whether the range of stochastic earthquake responses of the bridge structure was possible to endanger the structural safety because of changes of structural parameters , thus providing ref-erence to seismic design and research of long-span cable-stayed bridges .