岩土工程学报Issue(7)：1289-1301,13.DOI:10.11779/CJGE201407013
不同地层波速模型对沉积谷地地震响应规律的影响：FEM-IBIEM模拟研究
Effect of different wave velocity models on seismic response of alluvial valley based on FEM-IBIEM
摘要
Abstract
Accurate wave velocity model is essential for site effect analysis, while there is large uncertainty in determining the actual wave velocity. The simplified homogeneous and layered model is usually adopted, or the wave velocity is assumed to vary linearly, quadraticly and exponentially according to the drilling data. However, the effect of different velocity models on seismic response of the alluvial valley is not clear. It is attempted to reveal the influence mechanism through quantitative analysis both in frequency and time domains using an accurate finite element-indirect boundary integral equation method. The numerical results show that for incident low-frequency waves (η<0.3 ), different velocity models have little influence on the surface displacement amplitude. As the frequency increases, the influence becomes more and more significant. The difference between the linear model and homogeneous model is highlighted. It is found that the high-frequency resonance and the basin edge effect in the case of linear models seem more remarkable, which lead to the concentration of earthquake energy mainly in the near surface layer, the surface displacement amplitude in the valley is significantly enlarged, and the duration of earthquake ground motion increases obviously as well. In addition, the alluvial valley shape and the incident angle also have significant influence on the scattering characteristics of seismic waves, and the focusing area varies for different wave types. It is necessary to obtain wave velocity structure and boundary geometrical features of actual alluvial valley for the accurate simulation of earthquake ground motion.关键词
沉积谷地/地震响应/FEM-IBIEM耦合法/地层波速模型Key words
alluvial valley/seismic response/FEM-IBIEM coupling method/wave velocity model分类
交通工程引用本文复制引用
刘中宪,王冬..不同地层波速模型对沉积谷地地震响应规律的影响：FEM-IBIEM模拟研究[J].岩土工程学报,2014,(7):1289-1301,13.基金项目
国家自然科学基金项目（51278327）；国家重点基础研究发展计划（973计划）(2011CB013603)；天津市应用基础与前沿技术研究项目 （2011CB013603）
