Study On Simulation Of 3-D Strong Ground Motion

Seismic hazard assessment based on urban under active faults can provide scientific bases for city planning and project construction, while numerical simulation of strong ground motion is an important method for seismic hazard prediction and assessment. The physical model, namely 3D underground velocity structural model for large city urban, runs through the simulation work. A fine model in conformity with real strata is a prerequisite to ensure the reliability of the simulation results. The data used for modeling are synthesized from seismogeological data, topographic data, geological lay-order, seismic exploration results, microtremors data, wave borehole data, wave velocity measurements and GPS observed data. Stratigraphic division is based mainly on seismic wave velocity, with strata sequence taken into consideration. The model construction is finally accomplished with the many softwares, such as ArcGIS, Golden Surfer and with many relevant programming techniques via layer-by-layer stacking (in depth direction) of the adjacent medium interfaces(named meshes). In the Paper, we give a detailed account of the technical scheme and process. The paper includes modeling data form and the method for using, the model coordinate system, data qualification, data collection, data integration, the method of revising model, data storage, data increasing, rectifying abnormal data, optimizing model(B-spline Function), and the validate with the result of simulating Kunming Basin. The process and the technology form a scientific system of modeling. With the system of modeling, we choose Kunming City as the experience object, for 3-D model to simulate seismic with calculus of differences and for the seismic space response. Besides, the model is well compatible, easily used, easily upgraded, and easily rectified. It only needs a little storage space. Consummating the 3D model will be quicken the process of the seismic hazard assessment for national large cities, and it is also very significant in the relative fields of earthquake disaster study.