Ground Motion Characteristics And Simulations On Ground Effects

Ground motion characteristics, site conditions, and the corresponding nu-merical modelling methods are tightly coupled research topics in earthquake en-gineering regarding to seismic wave propagation. Therefore, we need to study in detail for the ground motion characteristics and site condition parameters. Numerical modelling is an important technique to analyze the process of seismic wave propagation, and help to recognize the influence by critical ground motion characteristics and site conditions. Thus, reliable and stable numerical modelling methods are key factors to this research.This research report is mainly focused on the following works regarding to the analysis of strong ground motion characteristics and the simulation of ground effects.1. Orientational characteristics of ground motion have been studied in de-tail. The concept of omni-spectrum is proposed and also we propose a fast algorithm for computing orientation-independent ground motion measures.2. We propose a method to keep ground motion characteristics of seed ground motion in the process of spectral matching. In the adjustment of ground motions, a new wavelet is proposed, which has the properties of no-drift after double integration and compactness in the time domain. This wavelet is effective used in the optimization framework for spectral matching.3. For the critical parameter VS30in site conditions, we propose a new model to estimate VS30based on the property of conditional independence. For the topographic effects in site conditions, we have carried out a practical research using numerical methods for the Lushan earthquake.4. We propose the combination approach between spectral element method and transmitting boundary formulas. The stability problem for the com- bination is discussed in detail and some measures are given to solve some instability phenomena.