【摘要】 提出了近断层地面运动的衰减模型,对全球范围内6.0≤MW≤7.6且震源深度均小于20km的636条地震动加速度峰值进行了统计分析,确定了本文研究的近断层区域为断层距25km,利用此范围内的440条记录进行了近断层加速度衰减规律的研究。水平地震记录分为硬土和软土两种场地类型,竖向地震记录只考虑土层场地,利用最小二乘法进行数据拟合分析,得到PGA随断层距和震源深度变化在不同震级处形成的衰减曲面,分析了近断层处水平、竖向的PGA以及竖向与水平PGA之比(V/H)的衰减规律。更多还原

【Abstract】 A new near-fault attenuation model is proposed.A worldwide database consisting of 636 strong-motion records from earthquakes with Mw=6.0～7.6 and depth≤20km is formed. After mean statistics of these records, we think that the characteristics of near-fault ground motion are notable when the distance to fault is less than 25km. Using these 440 records (fault distance not larger than 25km) from 22 earthquakes, near-fault attenuation characteristics of horizontal and vertical peak ground acceleration are studied. Horizontal data are grouped into stiff soil and soft soil site and vertical data are only regarded to soil site. The parameters are calculated by least square method. For a magnitude, PGA attenuation curve surface is drawn in 3d coordinate axis. Near-fault peak horizontal and vertical ground accelerations and V/H attenuation relationship are studied.更多还原