高墩大跨连续刚构桥梁的地震经济风险分析

摘要

在基于性能的地震工程风险评估框架基础上,针对某高墩大跨连续刚构桥,选用一组地震记录,利用增量动力分析( IDA)方法,借助桥墩损伤状态研究成果,建立解析损伤脆弱性函数,通过假定损失比,将桥梁结构的地震经济风险表达为年预期损失(EAL)形式.实例分析结果表明:在设定地震下,由于中小级别地震所造成的年预期损失约占总损失的72％.对于地震多发地区,高墩大跨连续刚构桥的地震经济风险主要来自于中小地震的危险性,决策者应采取适当措施减小地震经济风险.%Based on the performance-based earthquake engineering assessment framework, under a suite of earthquake records selected, by virtue of experimental damage results of bridge piers and assumed loss ratio, the seismic financial risk can be expressed in term of expected annual loss (EAL) for high-pier and long-span rigid frame bridge with incremental dynamic analysis (IDA) performed and analytical damage fragility function developed. The result indicates that moderate-and-low level earthquakes result in expected annual loss taking up 72% of the total. In earthquake-prone zone, the seismic financial risk is mainly from the hazard of moderate-and-low level earthquakes, for which decision-makers should take action to reduce seismic financial risk properly.