摘要
基于液化侧向变形实用统计模型和地震概率模型,建立了可以考虑地震随机特征和土体性质不确定性的液化侧向变形超越概率模型框架,通过实际案例初步探讨了模型的有效性,并将超越概率模型与现有统计模型的预测结果进行了对比。分析结果表明,若液化侧向变形的条件概率满足正态分布,标准差在5%到20%期望值范围内变化时,对位移超越概率影响不大;若满足对数正态分布,标准差对超越概率有一定影响。实用统计模型只能预测指定地震水平下的液化侧向变形值,而超越概率模型考虑了指定时间内所有可能地震的发生概率,可以同时预测变形值及发生概率,更加适合用于区域性的地震液化灾害评估。
This paper proposes a fundamental framework for assessing the exceedance probability of liquefaction-induced lateral displacement within an exposure time period considering seismic randomness and uncertainty of soil properties by combining an empirical regression model of lateral spread and the joint probability model of seismicity. The effectiveness of the proposed model is demonstrated through a case study. The prediction provided by the proposed model is compared with the results generated by several available empirical regression models. Results show that the standard deviation has insignificant effect on the results if the conditional probability of lateral spread is normal distributed and the standard deviation ranges from 5% to 20% of the mean value, while it affects results to a certain extent if the conditional probability is lognormally distributed. The empirical regression models can only predict the magnitude of lateral spread for a given seismic level; while the proposed model is able to simultaneously predict the value and the likelihood of lateral spread due to considering uncertainty of all possible seismic levels in a certain exposure time period. Thus the proposed model is more appropriate for the aim of regional assessment of liquefaction hazard.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2015年第12期3548-3555,共8页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.41102173
No.41572267)
教育部留学回国人员科研启动基金~~
关键词
液化
侧向变形
超越概率
不确定性
风险
liquefaction
lateral displacement
exceedance probability
uncertainty
risk
