地震安全性评价中地震动衰减关系的类型及其选取  

Type and Selection of the Ground Motion Attenuation Relations during Seismic Safety Evaluation

作　　者：文雯[1,2] 陈宇军[2] 王珏[2] 邓晓华[3] 杨雅琼[4] 

机构地区：[1]中国科学技术大学,安徽合肥230026 [2]云南省地震局,云南昆明650224 [3]中国地震局地球物理勘探中心,河南郑州450023 [4]河北省地震局,河北石家庄050021

出　　处：《地震工程学报》2013年第3期709-714,共6页China Earthquake Engineering Journal

摘　　要：通过阐述地震安全性评价工作中地震动衰减关系的演变介绍了衰减关系的三种类型,其差别在于是否含有高频地震动震级饱和因子C3M2项和加速度近场饱和因子C5eC6M项;分析了这两个因子的由来和作用,并举实例说明,当场地所处的地震环境受高频地震动影响较小时,可忽略C3M2项的影响;而加速度近场饱和因子因包含了震源体尺度的影响,并与实际观测记录相符,是衰减关系必须包含的内容。Through the description of the evolution of attenuation relation,three types of attenuation relations are introduced （type Ⅰ,type Ⅱ,type Ⅲ）,with the differences among them including whether they contain the high-frequency ground motion magnitude saturation factor C3M2 （a non-linear attenuation factor of magnitude M） and the acceleration near-field saturation factor C5eC6M （a distance factor）.The origins and functions of two such factors are analyzed in this study.The ground motion increases with the increasing of M,but the amplitude of it rapidly decreases with the increasing of M.C5eC6M plays a role in the seismic source body＇s range scale,in which the ground motion varies not along with the distances’ change in the epicentral area.The combined effects of C3M2 and C5eC6M strongly inhibit the false information that the near-field ground motion is too large in the case of high-magnitude,so as to reach a level consistent with the actual situation.The acceleration near-field saturation factor C5eC6M is the content that the attenuation relation must contain,because it contains the influences of the seismic source size and correlates with the actual observation data.In the seismic safety evaluation,C3M2 item can be chosen according to the local seismic environment.Examples are presented to explain that the influences of C3M2 can be neglected and the attenuation relation without C3M2 can be selected during the seismic safety evaluation when the local seismic environment suffers from fewer influences due to the high-frequency ground motion;if the local environment has more influences,an attenuation relation with C3M2 should be selected.This essay chooses of a set of type Ⅱ and then a set of type Ⅲ to make a comparative analysis of the attenuation relation.In general,type Ⅲ decays faster than type Ⅱ.As the distance increases,the peak accelerations with the use of type Ⅲ are smaller than that with the use of type Ⅱ.In addition,type Ⅲ matches well with the actual records in the case of h

关 键 词：衰减关系 高频地震动 震级饱和因子 加速度近场饱和因子 

分 类 号：P315.912[天文地球—地震学]