ESTIMATION OF PROBABILITY-CONSISTENT SCENARIO EARTHQUAKE

摘要

The conventional probability seismic hazard analysis method suggested by Cornell (1968) is useful to estimation of ground motion intensity for seismic design, but there are no seismic backgrounds, such as magnitude, epicenter and orientation, for the intensity. Another method, which is also often used for seismic design, is that the ground motions are simulated for a given scenario earthquake and a epicentral distance, but this method is deterministic method and the estimated motions are also deterministic rather than probabilistic. Luo presented the definition of probability-consistent scenario earthquake (PCSE) in 2000. In this paper we present two evaluation methods of the magnitude, epicentral distance and orientation of PCSE. One is trial-error method and another is net-scan method. As an example of application, corresponding to 3% probability of exceedance, the magnitude of PCSE near Shanghai area is calculated. The results show that the two methods are uniform. And the net-scan method is easily to manage by engineers. At last, as an application of PCES, the observed small earthquake record is used as empirical Green's function to synthesize ground motions of the estimated PCSE. The peak value of synthetic acceleration is consistent with the result analyzed by probability seismic hazard analysis method.