川藏铁路大跨度桥梁抗震设防标准研究

摘要

T he location of a large number of long‐span bridges in highly seismic zone is one of significant features of the Sichuan‐Tibet railway .The determination of the seismic design criterion is crucial for the seismic design of large‐span bridges of Sichuan‐Tibet railway .Based on the relationship between the exceedance probability and the return period of earthquake ,the seismic design criteria for typical long‐span bridges at home and abroad were analyzed in detail .Combined with the law between seismic acceleration and exceedance probability ,the return periods corresponding to the railway bridge of class B in different regions were obtained through calcula‐tion ,to define the seismic design criterion for the railway bridge of class B .With seismic return period being used as the main index ,the seismic design criteria for typical long‐span bridges of Sichuan‐Tibet railway and earthquake importance factor corresponding to different intensity were discussed .The results can be used as a reference for seismic design of long‐span bridges .%高烈度地震区大跨度桥梁较多是川藏铁路的特征之一，确定抗震设防标准是川藏铁路大跨度桥梁抗震设计首先需要解决的问题。从超越概率与地震重现期关系入手，详细分析国内外典型大跨度桥梁的抗震设防标准，结合设计地震加速度与超越概率的关系，计算得到铁路B类桥梁的重现期，明确其抗震设防标准。以地震重现期为主要指标，探讨川藏铁路大跨度桥梁的抗震设防标准及不同烈度多遇地震对应的重要性系数，可供铁路大跨度桥梁抗震设计参考。