Accurary Comparison Of The Explicit Numerical Simulation For Ground Motion On2D Complex Sites

Large earthquake damage investigations indicate that site conditions have important influence on ground motion. The damage index in complex site conditions such as the fault, the scarp basin and the ridge will be higher than the flat field, and in theory the building should avoid these adverse site as far as possible. However, realistic conditions in China, such as large population, the limited land resources and so on, which is difficult to completely avoid the disadvantage, so it will help to establish the seismic fortification criterion to study the effect of local complex site conditions on the ground motion. The seismic numerical simulation of complex site model is the key technology to provide the prediction of earthquake damages and earthquake resistant design. The traditional time domain finite element method may encounter some difficulties in the simulation of complex sites. As this method must adopting dense grid, taking a relatively long computing time and the choosing of model size is restricted etc, so this restricted the complex site to further improve the precision of the simulation. This thesis adopted the time-domain explicit spectral element method based on the high-order interpolation and the time-domain explicit finite element method commonly used in engineering and it also comparatively analyses the numerical simulation results of several kinds of typical complex site. It aims to explain the numerical simulation precision level of complex site ground motion and discuss the rationality and problems of the existing method to simulate complex field, and some meaningful conclusions are obtained. The studies done in the paper include:1. Based on different finite element models, the ground motion feature of the homogeneous half elastic space, scarp and convex and concave mode is studied using explicit finite element methods, the simulation accuracy and the reliability of the existing calculation model and the numerical simulation methods is pointed out.2. Based on the same analysis model of the explicit finite element method, the numerical accuracy and reliability of the two explicit methods is comparatively studied using the time-domain explicit spectral element method to study ground motion.3. The remote border is used to eliminate the influence of the artificial boundary when the domain precision comparison. In order to study the influence of the artificial boundary on the numerical simulation accuracy and to further select the domain model with same accuracy, the precision difference of viscoelastic artificial boundaries^transmitting artificial boundary and Perfectly matched layer(PML) boundary is researched. 4. Based on the research in this paper, a summary is given and thus put forward the outlook for the future research work.