GIS Based Information Retrieval System For Seismic Design Ground Motion Parameters

Geographic Information System (GIS) has been one of the most powerful tools for earthquake disaster reduction. In this paper, efforts are devoted to establishing GIS based computerized system for earthquake resistant design ground motion. The main research and achievement could be summarized as follows: 1. The methodology for design GIS based information retrieval system for seismic design ground motion parameters is developed and presented. For the purpose of establishing a GIS based seismic design parameters retrieval system, the main principle and technology means of the system development are established. Key steps of the system development are also described. The system frame work and main function modules are introduced. With the overview of ArcView, the GIS software platform developed by ESRI Corporation, is recommended for the parameters of ground motion information retrieval system. The system hardware configuration and system development method are introduced. 2. The database of the parameters of ground motion and the severest seismic design ground motion is established. The database of the parameters of ground motion and the severest seismic design ground motion is mainly presented in vector data, and partially grid data. The exchange among various kinds of data is studied. The logical organization of database is designed, and horizontal and vertical models are finally applied. Different methods are used to build the parameters of ground motion database, including digitizing maps, transferring data from geometry coordinate, operating spatial analysis etc. 3. Through collecting and putting the data in order, the system have realized the inquiry function of the ground motion parameter under the environment of GIS. On the basis of fully considering the difference in various areas and many kinds of uncertain influential factors in 2240 cities, the values of exceeding probability and corresponding probability of occurrence in 50 years , basic intensity and effective peak acceleration are obtained by consulting《Code for Seismic Design of Building(50011-2001)》and《New Seismic Zoning Map of China(2001)》. Based on GIS, according to the need of consumers, two methods are presented and applied: combined inquiry and fuzzy inquiry. 4. As a demonstration, GIS based information retrieval system for the parameters of ground motion and the severest seismic design ground motion is built. In order to consider the earthquake hazard difference in Guangdong province, and avoid the conflict of the seismic design criterion in different areas, the method to deduce formulas of hazard curve of several parameters making use of basic intensity given by the Seismic Intensity Zoning Map(1990), the seismic coefficient, the earthquake influence and effective peak acceleration is presented, and exceeding probability and corresponding probability of occurrence in 50 years in various are computed. By analyzing the seismic hazard characters of 79 cities in Guangdong province, the values of fortification intensity, earthquake influence coefficient, earthquake coefficient and effective peak acceleration forfrequent occurred and occasional occurred earthquake are obtained. In addition, the concept of the severest design ground motions is presented and the method for determining severest design ground motions is also given. The input design ground motions corresponding to different site conditions and in terms of three period ranges of structures for different earthquake hazard areas are selected out, which provide a new approach for selecting input ground motions. On the basis of these two parts, GIS based information retrieval system for the parameters of ground motion and the severest seismic design ground motion is built. 5. With integration of information retrieval system, it is proved that the ideas which is applied in this paper are application. Based on the research work above, the information retrieval system is integrated. The system having been tested, it is proved that the frame to built the GIS based information retrieval system is applicable and useful.