Probabilistic Seismic Hazard Analysis Including Aftershocks

Abstract

The purpose of this paper is to investigate the impact of the addition of aftershocks on the probability seismic hazard analysis and to compare the increase of PGA annual rate in different cases exclude and include the aftershocks It is mainly divided into two parts The first part is the verification of the program according to the case of PEER2018/03 The second part considers the PGA annual excess probability of include aftershocks Assume that the aftershocks are uniformly distributed around mainshock Fault source surface source and single source were analyzed and compared The conclusions of this paper are as follows: (1) The core software selected by PEER2018/03 does not absolutely represent the actual PGA annual probability of excess If judged by all software the result will be more credible The program results of this paper are all located between the maximum and minimum values of all software then interfering that the results is reasonable (2) Some software results of PEER2018/03 are not same in the symmetric two sites The judgment is that the number of moving steps of the cracking surface is not corrected to an integer (3) The PGA annual probability of excess of each site will increase after the addition of aftershocks The rate of increase is closely related to the magnitude of the mainshock and the location of the site and is most affected by the relative position of the site and the source (4) The rate of increase caused by aftershocks will increase at high PGA Therefore it is necessary to judge the need for PSHA to consider the effect of aftershocks (5) The farther the site is from the fault the greater the impact of the aftershocks is The aftershocks are widely distributed and evenly distributed (6) The site with the highest contribution to the aftershock damage of the surface source is located in the center of the circle which is due to the main shock far from the central site The chances of the other earthquakes returning to the vicinity of the site are higher than those of other sites (7) When the mainshock is a single source the closer the site is to the mainshock the lower the contribution of the aftershock make and vice versa

Date of Award	2020
Original language	English
Supervisor	Li-Ling Hong (Supervisor)