利用场地表征参数研究岷漳地区地震动相对变化趋势  

Study on Relative Variability of Ground-motion in Min-Zhang Region by Using Representative Site Parameters

作　　者：卢育霞[1,2,3] 王良 魏来[1] 刘琨 车高凤[1,2,3] 李少华 LU Yuxia;WANG Liang;WEI Lai;LIU Kun;CHE Gaofeng;LI Shaohua(Key Laboratory of Loess Earthquake Engineering, Lanzhou Institute of Seismology, CEA, Lanzhou 730000, China;Geotechnical Disaster Prevention Engineering Technology Research Center of Gansu, Lanzhou 730000, China;Earthquake Administration of Gansu Province, Lanzhou 730000, China)

机构地区：[1]中国地震局兰州地震研究所黄土地震工程重点实验室,甘肃兰州730000 [2]甘肃省岩土防灾工程技术研究中心,甘肃兰州730000 [3]甘肃省地震局,甘肃兰州730000

出　　处：《防灾减灾工程学报》2018年第2期359-366,共8页Journal of Disaster Prevention and Mitigation Engineering

基　　金：“十三五”国家重点研发计划项目课题(2017YFC1500906);中国地震局地震预测研究所基本科研业务费项目(2015IESLZ05);国家自然科学基金项目(51248005)资助

摘　　要：近地表场地条件所引起的地震动差别可以造成不同场地上建筑物震害的显著差异。为了在岷漳地区的震害预测和长期发展规划中考虑场地条件差异性,提出联合V（s30）和地形标度曲率作为场地表征参数来获得研究区地震动相对变化趋势图的方法。研究表明：土质山体〉土质河谷〉基岩山体〉基岩河谷是研究区地震动变化的基本规律,但因覆盖层厚度和地形条件的不同,具体场地的地震动变化也有不同。总体上,地震动峰值加速度的放大程度主要与近地表V（s30）相关,V（s30）越大地震动峰值加速度的放大越小,地震频谱受频率标度地形曲率和覆盖层厚度共同影响,分别在相应的特征频率处放大。该研究可为区域地震动预测提供理论依据,为制定区域长期发展规划和建筑抗震设计提供重要的基础资料,基于场地表征参数研究区域地震动相对变化趋势的方法也可应用于地震烈度速报和地震灾害快速评估等领域。Difference of ground motion caused by site conditions near the ground surface makes seismic hazard disparity.In order to assess the impact of surface site conditions on seismic hazard prediction and long-term development program in Min-Zhang region,aground motion variability calculation method is proposed by combining V_（s30） and frequency-scaled topographic curvature as properties for site effective amplification.This study shows：although PGA of ground-motion varies with the soil thickness and topography,the descending sequence of ground motion variability is soil hill,soil valley,rock hill and rock valley.Generally,the amplification factor of ground motion is correlated with V_（s30）,that is,higher V_（s30） is corresponding to a lower amplification factor.In frequency domain,the amplitude of seismic spectrum,which depends on both V_（s30） and frequency-scaled topographic curvature,amplifies obviously at the characteristic frequency.This study can offer a theoretical foundation for assessment of the seismic hazard prediction and longterm development program in the study area,and the proposed method can also be used in rapid reporting of seismic intensity and seismic disaster assessment.

关 键 词：场地条件 地震动 Vs30 频率标度地形曲率 震害预测 

分 类 号：P315.9[天文地球—地震学]