A Method Of Ground Motion Parameter Zoning And Its Application In Rapid Assessment Of Seismic Intensity After Earthquake

The thesis take FuZhou Basin as an example , a new method for urban seismic parameters'zonation is proposed, and then used for swift evaluation after earthquakes. That is, started with underground structure model, site conditions'effect ( landform, soil layer thickness and soil property ) is fully considered, soil layers'enlargement effect for earthquake wave under input wave of different intensity is studied ,then used as the foundation for calculating surface earthquake field, distribution of earthquake field under input earthquake wave of different intensity can be got; after earthquakes ,according to the seismic record , earthquake acceleration contour line and intensity distribution map are plot swiftly ,it can be regarded as swift evaluation after earthquake for reference.There are some achievements:1.According to the known geology material,land forms,bore-holes,wave speed in each layer and other materials, Fuzhou Basin 3D uneven soil layer model is established with software Surfer and ArcGis. Further more, density, Soil dynamic parameters and depth-Shear wave velocity regression relations ( h ? v) of 7 kinds of soil are gained.2. The site is divided according to soil layer thickness and Site partition , and grids division is done, several representative bore-holes in each subarea are selected for one-dimensional response analysis ,enlargement effect under different intensities is got.3. Seismic intensity distribution of three exceedance probabilities (63%, 10% and 2%)of Fuzhou basin is got with the calculated results of representative bore-hoes, compared with the underground information of uniform mesh point,as well as seismic design response spectrum of three exceedance probabilities.4. Rapid assessment system of earthquake effect in Fuzhou basin is established. When an earthquake take place , if there is a strong earthquake records, acceleration peak can be directly got; Without strong earthquake records, acceleration peak can be got by peak attenuation relationship according to the epicenter position and magnitude . According to all the discrete points'(grid point) information in the area and surface amplification coefficient, surface seismic response result of the whole area can be got ,further more, the ground motion distribution of rapid estimation of the whole area can be got .