【摘要】 汶川地震诱发大量山地斜坡次生灾害具有明显的地形分布特征,对其地形放大效应研究具有重要的理论及实际意义。斜坡震害调查表明,宏观地貌单元对次生地质灾害的发育类型具有控制作用,中高山区以大中型滑坡、崩塌为主,低山及丘陵区以山体震裂、小型崩塌为主;峡谷形态对次生地质灾害的发育密度具有明显影响,其中"V"型峡谷发育密度高于"U"型峡谷;单薄山脊、条形山体、坡型转折部位、凸出地形等微地貌地形放大效应明显。监测显示,不同方向水平分量地震波峰值(PHA)相差可达10余倍,研究表明:地形尺寸与地震波波长的耦合作用使得地震动水平分量放大显著。更多还原

【Abstract】 Physical and mechanical property of rock and soil mass may change across with the different spatial position,so it has different wave impedance characteristics.Under strong earthquake condition,stress wave during its propagation process usually produce strong reflex and refraction effects in the interfaces of different physical properties,and form strong dynamic tension stress and dynamic shear stress,resulting in failure in the rock and soil mass or forming an unique characteristic of dynamic instability.Based on surveying dynamic failure characteristics of rock slope triggered by the "5.12"Wenchuan earthquake and understanding of differences geological media of unstable slope,recurring to parameter test of rock body,theories research,numerical simulation and so on,at the same time combined with analysing characteristic of seismic-dynamic monitoring in different venues media,analysing data of soft and hard lithology combined model tested on the the large-scale shaking table,we research dynamic mutagenic effect of rock and soil media interfaces.The project is expected to reveal rock media dynamic characteristics of representative seismic landslide,dynamic characteristics of media interface,and based on the study it is expected to explore dynamic tension stress and shear stress of media interface impact on slope stability.Research results can provide scientific basis for town construction and major engineering construction in high intensity mountain area.So It has an important significance of earthquake preparedness and disaster reduction.更多还原