[S-SS15] [JJ] Strong Ground Motion and Earthquake Disaster

[SSS15-05] Analysis of Systematic Path Effects form Ground-Motion Variability Using Different Path-Bin Plans

*CHIH HSUAN SUNG¹, Chyi-Tyi Lee¹ (1.National Central University-Graduate Institude of Applied Geology)

Keywords:GMPE, aleatory variability, strong ground motion, path effect, PSHA

This paper describes the path diagram method should aim to the record-to-record residuals of a single earthquake instead of a single station, to solve the limitations of the bracket. We use 150 shallow earthquakes with moment magnitudes greater than 4.0 obtained from the Taiwan Strong-Motion Instrumentation Program network to build the Taiwan ground-motion prediction equations for peak ground acceleration and spectral accelerations with 5% damping for different structural periods. The record-to-record residuals are divided into small brackets in a path diagram for six distance bins and twenty-four azimuth bins. The mean residuals are estimated for each path bin, from which we can get 144 inter-path residuals for a source and compute a repeatable path-term for all inter-path residuals. Comparing the results with those obtained with the same data, but using the path diagram of a site, show that we obtain a lower remaining variance and the higher repeatable path-term with the 15° bracket of the path diagram approach for a source. The remaining unexplained intra-event standard deviations are 40-44% smaller than the record-to-record standard deviation for peak ground acceleration and spectral accelerations at periods of 0.3, 1.0, and 3.0 seconds. The results of path-to-path variability of each earthquake show that some earthquakes of small magnitude have a higher sigma because their source-to-site distances almost locate in the range of 0-50 km.