Li, Yanan

Strong Ground Motion Simulation for Recent Earthquakes in China

Abstract eng:
Stochastic point source method with its extended version finite fault method is widely used to simulate strong ground motions around the world. In view of the limitation of uniform slip distribution in point source method with effective distance (R EFF ), a new modified version of the stochastic method based on a proposed equivalent distance (R EQL ) measure is proposed. To incorporate the effect of heterogeneous slip distribution on previous modified point source method, the uneven slip values are first transformed to distance value assigned to sub-faults, and then solved for the comprehensive distance R EQL iteratively to the path spreading functions. At last, the ratio of total spectrum Y for non-uniform and uniform slip distributions can be obtained from the path term in Y spectrum. The new modified method is used to simulate two recent earthquakes in China, The Wenchuan (Mw=8.3, 12 May, 2008) and Ludian (Mw=6.2, 3 August, 2014) earthquakes. For Wenchuan earthquake, envelop method is combined with the new present method to simulate the waveform of the acceleration time history because its fault is relatively long. Simulation results for 6 stations around the fault indicate that the present method could simulate the direction and hanging wall effect of strong earthquake. For Ludian earthquakes, parameters are investigated by analyzing 69 recorded accelerograms. Comparisons between observed and simulated parameters, such as peak ground acceleration (PGA) against R EQL , waveforms and pseudo-spectral acceleration (PSA), indicate that the simulation parameters and results for Ludian earthquake (Mw 6.2, 3 August, 2014, China) are quite acceptable. Furthermore, the ShakeMaps of Ludian in terms of PGA simulated by the present method and finite-fault method are further compared with intensity map published by China Earthquake Administration, which also confirms the validity of the new simulation procedure for the purpose of regional strong ground motion estimation. The simulation results also indicate that input parameters for the two earthquakes are similar. The proposed method has the advantage of simple and efficient on computation efficiency.

Contributors:

Wang, Guoxin

Conference Title:

Proceedings of the 16th World Conference on Earthquake Engineering

Conference Title:

16th World Conference on Earthquake Engineering

Conference Venue:

Santiago (CL)

Conference Dates:

2017-01-09 / 2017-01-13

Rights:

Text je chráněný podle autorského zákona č. 121/2000 Sb.