基于地质环境分区的中国大陆场地剪切波速外推模型

使用相关结果请引用“李柯苇, 谢俊举, 李小军. 2025. 基于地质环境分区的中国大陆场地剪切波速外推模型. 地震学报.” (2025年5月录用) Please cite the work as: Li Kewei, Junju Xie, Xiaojun Li. 2025. Development of Regional Shear Wave Velocity Extrapolation Models for Mainland China Using Geological Environmental Zoning. Acta Seismologica Sinica. (Accepted, in Chinese) 为提高剪切波速外推模型的准确性,基于中国大陆地区9715个钻孔的实测剪切波速剖面数据,提出了一种考虑地质环境差异的中国大陆分区场地剪切波速外推方法。在此基础上,对比分析了全国19个地质环境亚区中分别采用常速度外推、速度梯度外推和基于Markov独立过程的条件独立外推等方法的适用性。研究结果表明:1)地质环境分区能有效表征区域间浅层岩土体速度结构的差异,相较于传统地理行政分区,显著提升了模型的区域适应性;2)条件独立外推方法在各类地质环境下均表现出最优性能,尤其在测试深度较浅时,其误差显著低于其他方法;3)在黄淮海—长三角平原区等典型区域,模型验证显示分区方案能更准确地捕捉沉积环境差异对剪切波速的影响。建立的中国大陆场地剪切波速分区方案和区域外推模型可以为中国场地分类和地震动预测提供更可靠的场地剪切波速参数,进而为工程抗震设计及地震风险评估提供基础支持。 To improve the accuracy of shear wave velocity extrapolation models, this study analyzed the shear-wave velocity measurements of 9,715 boreholes across Chinese Mainland. A novel regional classification scheme accounting for geological environmental differences was proposed. The study systematically compared the applicability of several extrapolation methods in 19 geological environment subzones, such as the bottom constant velocity extrapolation, velocity gradient extrapolation, and conditional independent extrapolation based on Markov processes. The key findings include: 1) The geological environmental zoning effectively characterizes regional variations in shallow soil velocity structures, demonstrating significantly better regional adaptability than traditional administrative division-based approaches; 2) The conditional independent extrapolation method exhibited optimal performance across all geological environments, particularly showing superior accuracy with shallower measurement depths; 3) Model validation in typical regions like the Huang-Huai-Hai and Yangtze River Delta plains zone confirmed that the proposed zoning scheme better captures the influence of sedimentary environmental variations on shear wave velocities. The developed regional extrapolation models developed in this study can provide more reliable site shear-wave velocity parameters for both site classification and ground motion prediction in China, thereby offering fundamental support for seismic-resistant design and earthquake risk assessment. 附表1 各波速外推方法II区分区模型回归分析结果汇总 附表2 19个地质环境亚区基于条件独立方法得到的VS[zp,30]与VS(zp)回归分析结果汇总 附表3 19个地质环境亚区基于条件独立方法得到的VS[zp,20]与VS(zp)回归分析结果汇总 Appendix Table 1 Summary of regression analysis results for different wave velocity extrapolation methods in subzone models of Zone II. Appendix Table 2 Summary of regression analysis results between VS[zp,30] and VS(zp) for 19 geological environment subzones based on the Dai et al (2013)'s conditionally independent method. Appendix Table 3 Summary of regression analysis results between VS[zp,20] and VS(zp) for 19 geological environment subzones based on the Dai et al (2013)'s conditionally independent method.