摘要
为了在桥梁设计和评估中充分考虑多灾害影响,基于一致风险原则,提出桥梁在考虑冲刷和地震联合灾害作用条件下的分析框架,开展了考虑地震灾害的合理冲刷深度研究.首先对桥梁进行考虑冲刷的地震易损性分析,获得结构的易损性曲线和易损面;根据两种灾害的危险性模型,获得不同给定冲刷深度下失效概率与冲刷深度的关系及联合失效概率.然后将联合失效概率所对应的冲刷深度作为两种灾害组合时的合理冲刷深度,进一步与设计冲刷深度比较,得到地震和冲刷多灾害下桥梁设计中所需要的冲刷荷载组合系数,并以一悬索桥为例说明分析过程.文中方法有效考虑了桥梁整体风险和经济性,可为地震和冲刷联合灾害作用下不同类型和大小的桥梁的探索分析提供基础.
In order to guide the future design of new bridges or the assessment of existing ones,a multi-hazard design framework is proposed on the basis of risk-consistent design for bridges under earthquake and scour hazards,and the appropriate scour depth considering the earthquake is investigated. Firstly,a fragility analysis considering scour is carried out for the bridge under earthquake to obtain the fragility surface and fragility curve of the bridge.Secondly,two probabilistic risk models respectively corresponding to earthquake and scour hazards are proposed and are used to reveal the relationship between the failure probability under seismic hazard and the scour depth and to obtain the joint failure probability of the bridge. Then,the scour depth corresponding to joint failure probability is taken as the appropriate scour depth to make a comparison with the designed value,from which load combination factors for bridge design are determined. Finally,a case study on a suspend bridge is carried out. The results show that the proposed method effectively considers both bridge risk and economy,so that it lays a foundation for exploring the combined action of earthquake and scour hazards for bridges with different types and scales.
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2016年第3期103-109,127,共8页
Journal of South China University of Technology(Natural Science Edition)
基金
"十二五"交通运输部重大科研专项(2011318494160)~~
关键词
桥梁
风险
地震
冲刷
多灾害
bridge
risks
earthquakes
scour
multiple hazard
