Shakemap场地校正方法及其在云南地震动强度和烈度速报中的应用*

(1.昆明理工大学,云南 昆明,650093; 2.云南省地震局,云南 昆明,650224)

地震动强度; 地震烈度; Shakemap场地校正方法; 局部场地条件; 云南地区

Shakemap Site Correction Method and its Application in the Rapid Prediction of Ground Motion Intensity and Seismic Intensity in Yunnan
ZHANG Yan-qi1,2,FAN Zhu-guo1,CHEN Kun-hua2,CUI Jian-wen2,LI Shi-cheng2,RAN Hua2

(1.Kunming University of Science and Technology,Kunming 650093,Yunnan,China)(2.Earthquake Administration of Yunnan Province,Kunming 650224,Yunnan,China)

ground motion intensity; seismic intensity; Shakemap site correction method; local site condition; Yunnan region

备注

将美国Shakemap场地校正方法用于云南地震动强度和烈度速报工作,通过分析Shakemap场地校正方法及其要点,将该方法应用于云南典型区域与实际场地情况进行对比分析,探讨了Shakemap场地校正方法相关参数问题,认为将该方法用于研究云南地区时应对相关参数做一些改进,首先要对其只基于地形坡度单指标的场地条件分类进行补充,即应该考虑V30S与多指标因素的相关性(如近地表地质状况、高程、距离河流的距离等)。同时,必须从实际场地情况出发考虑局部场地条件对地震动的影响,主要从盆地软弱土层、地质构造条件和局部砂土液化场地等方面修正局部场地条件对地震动的放大作用。这样,在完善理论计算结果的基础上结合对实际场地情况的修正,通过理论与实际双重的校正,达到提高预测结果精度的效果,为震后的应急决策提供有用的信息和帮助。

Appling the Shakemap site correction methods of U.S. for the rapid prediction of ground motion intensity and seismic intensity in Yunnan,we analyzed Shakemap site correction method and its main points,and applied it to the comparison and analysis of typical regions in Yunnan and the actual site conditions,and discussed the relevant parameters problems of it. We should improve the relevant parameters of Shakemap site correction method in Yunnan. Firstly,we supplied the classification of site conditions only based on topographic slope single indicator,which should be considered the correlation between V30S and multi-index factors(such as the near-surface geological conditions,elevation,the distance from the river etc.).At the same time,we must consider the impact of local site conditions on ground motion in the actual site conditions and modified the amplification of local site conditions on ground motion from the soft soil of basin,the geological structure and the local sand liquefaction sites etc.. Basing on the theoretical calculation results,combining with modifying actual site conditions,we could improve the precision of predicted results by double correction of theoretical and practical,which could provide useful information and help for emergency decision after the earthquake.