Methodology and Assessment of Proxy-Based Vs30 Estimation in Sichuan Province,China

• 作者: Wen Wu Jifu Liu Lanlan Guo Zhifei Deng
• 来源期刊: 国际灾害风险科学学报（英文版）
• 年，卷（期）: 2020,（1）
• 所属期刊栏目: ARTICLES
• 页码范围: 133-144
• 页数: 12页
• 语种: 英文

摘要

Although time-averaged shear wave velocity to the depth of 30 m(Vs30)is an important indicator of earthquake site effects,it is difficult to obtain.Several proxies have been used either individually or in combina-tion to infer Vs30 values during seismic hazard estimation under limited observational conditions.Sichuan Province is an area highly prone to earthquakes.Complex geological structures and lack of drilling sites mean that it is partic-ularly important to establish a suitable approach for the estimation of Vs30 values for site classification.This study compared the application of three proxy-based approa-ches—geology-based,topographic slope-based,and ter-rain-based—to the estimation of Vs30 values in Sichuan Province.The results revealed that the residual between the measured logVs30 values and the estimations derived from the terrain-based approach was smallest,indicating best predictability.Stability analysis of the three approaches also showed that the terrain-based approach performed best.However,its performance in the plain area was poor,that is,the Vs30 values were mostly underestimated.This might indicate that the old strata,hard rock,and alluvial deposits formed by Quaternary glacier sediments were not identified appropriately in the plain area,highlighting the need for localized corrections.