A Probabilistic Liquefaction Hazard Assessment for Urban Regions Based on Dynamics Analysis Considering Soil Uncertainties
A Probabilistic Liquefaction Hazard Assessment for Urban Regions Based on Dynamics Analysis Considering Soil Uncertainties
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DOI：
10.1007/s12583-021-1431-1
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发表时间：
2021-10
影响因子：
3.3
通讯作者：
Jian Chen;H. O.-tani;T. Takeyama;S. Oishi;M. Hori
中科院分区：
文献类型：
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作者：
Jian Chen;H. O.-tani;T. Takeyama;S. Oishi;M. Hori
地震液化是威胁城市地区的主要地质灾害之一，它不仅会对建筑物造成直接破坏，而且会影响到实时的救灾和重建工作。因此，有效地进行城市液化危险性评价，对防灾减灾具有重要意义。传统的评价方法依赖于工程指标，如抗液化安全系数（FS），不能直接考虑土壤的不确定性。相比之下，基于物理模拟的方法，通过求解耦合超孔隙水压力（EPWP）的土壤动力学问题，可以直接通过蒙特卡罗模拟来模拟不确定性。在这项研究中，我们证明了这种方法的能力，评估城市地区超过10 000个网站。假设渗透率参数在每个站点的100个模型分析中遵循基数10对数正态分布。对每个模型进行了动态仿真分析，以获得EPWP结果。基于超过100万个EPWP分析模型，我们获得了概率液化评估。在高性能计算的支持下，我们首次提出了一种基于动力学分析的城市地区概率液化危险性评估方法，该方法考虑了土壤的不确定性。
Earthquake induced liquefaction is one of the main geo-disasters threating urban regions, which not only causes direct damages to buildings, but also delays both real-time disaster relief actions and reconstruction activities. It is thus important to assess liquefaction hazard of urban regions effectively and efficiently for disaster prevention and mitigation. Conventional assessment approaches rely on engineering indices such as the factor of safety (FS) against liquefaction, which cannot take into account directly the uncertainties of soils. In contrast, a physics simulation-based approach, by solving soil dynamics problems coupled with excess pore water pressure (EPWP) it is possible to model the uncertainties directly via Monte Carlo simulations. In this study, we demonstrate the capability of such an approach for assessing an urban region with over 10 000 sites. The permeability parameters are assumed to follow a base-10-lognormal distribution among 100 model analyses for each site. A dynamic simulation is conducted for each model analysis to obtain the EPWP results. Based on over 1 million EPWP analysis models, we obtained a probabilistic liquefaction assessment. Empowered by high performance computing, we present for the first time a probabilistic liquefaction hazard assessment for urban regions based on dynamics analysis, which consider soil uncertainties.