【摘要】 本文利用三维施甸盆地模型以及川滇地区的地壳速度结构,采用谱元法和并行计算技术,考虑地形的影响,模拟了盆地外围中等设定地震作用下施甸盆地地震波的传播,分析了面波的产生和传播,研究了该盆地不同位置剖面地震动的差异和原因。研究表明,小型盆地在中等地震的作用下盆地内部地震动空间差异很大,盆地中较深的小型凹陷更容易汇聚面波,形成更强的振动,位于覆盖层厚度剧烈变化区域的地震动强度也会很大,甚至大于覆盖层厚的区域。较基岩地震动,盆地内地震动持续时间明显增加,地震动的放大作用明显,这也是盆地震害严重的主要原因之一。更多还原

【Abstract】 Based on three-dimensional Shidian basin model and crust velocity structure of Sichuan-Yunan region,and considering the real topography,the seismic wave propagation of Shidian basin under moderate scenario earthquake is simulated by using spectral-element method and parallel computing technique.The generation and the propagation of surface waves are analyzed in this paper,and the ground motion of different profiles in the basin are compared and analyzed.Results show that for small-scale basin,the spatial discrepancy of basin-internal ground motion is considerable,little but deep hollow in the basin is easy to collect surface waves and produce much stronger ground motion.The area located in the drastic change of soil depth is also predominant for strong ground motion,which is even stronger than that of the area with greatest soil depth.Compared with the base rock the duration of ground motion increases significantly in the basin,and the amplification effect is more apparent.This is a main reason for the severe earthquake damage in the basin.更多还原