联塔分幅独塔斜拉桥非线性地震响应研究

Study of Nonlinear Seismic Response of Single Pylon Cable-Stayed Bridge Featuring a Jointed Pylon and Separated Decks

南仓道立交桥主桥采用联塔分幅、塔梁固结体系的独塔斜拉桥,跨径布置为2×150m,按照8度采取抗震措施。该桥跨越重要铁路干线,动力及抗震性能尤为重要,介绍该桥的构造特点、动力特性,对桥址地震安全性评价、地震荷载计算等方面进行研究,采用反应谱法、时程分析法对其抗震响应进行了对比分析,并对抗震措施进行了探讨。

The main bridge of Nancangdao Interchange is designed as a single pylon cablestayed bridge having a jointed pylon, separated decks and rigid fixity system of pylon and decks.The span arrangement of the bridge is 2 × 150 m and the bridge is seismically protected in accordance with 8 degree seismic intensity. As the bridge spans the trunk railway lines, the dynamic and seismic performance of the bridge is particularly important. In this paper, the structural features and dynamic performance of the bridge are presented, the study of seismic safety evaluation at the bridge site and seismic load calculation is described, the seismic response of the bridge is comparatively analyzed by response spectrum and dynamic time-history analysis methods, and eventually the seismic resistance design is discussed.