Dissertation Defense Announcement

The Herff College of Engineering announces the Final Thesis of

Farhad Sedaghati

for the Degree of Doctor of Philosophy

on March 5, 2018 at 1:00 PM in Engineering Science Building, Room 202C

Advisor: Shahram Pezeshk

Simulation of Strong Ground Motions using the Stochastic Summation of Small to Moderate Earthquakes as Green's Functions

ABSTRACT: As an application to the improved method, I produce a dense database from moderate to large earthquakes for CENA using synthetic weak motions as the seed. In this regard, I generate synthetic weak ground motion time histories using the stochastic method of Hanks and McGuire (1981) implemented in SMSIM (Boore, 2003). I use the recent estimated seismological characteristics for CENA to generate seed motions. The seeds for the SSGFM are simulated for 3 small earthquakes with M 3.5, M 4.0, and M 4.5, which can be effectively considered as a point source, at 26 sites with JB distances in a range of 1 to 1000 km. The point source effective distances selected in this dissertation are 9.2, 10, 11, 12.5, 14, 15, 20, 25, 30, 40, 50, 60, 70, 80, 100, 120, 150, 200, 250, 300, 400, 500, 600, 700, 800 and 1000 km. For each given point source effective distance, I simulate 5 weak motions using the SMSIM software. Strong ground motion time histories from 7 earthquakes with moment magnitudes from 5.0 to 8.0 are then simulated, in 0.5 magnitude unit increments, using generated seeds. To simulate synthetics of M5.0 and M5.5, I use seeds of M3.5 and to simulate synthetics of M6.0 to M7.0, I use seeds of M4.0, and for simulations of M7.5 and M8.0, seeds of M4.5 are employed. For each magnitude, 10 realizations are obtained resulting in 50 simulations at each given distance-magnitude bin. Therefore, a total of 8415 three-component ground motion synthetics all for generic hard rock sites will be provided along this dissertation for CENA. The synthesized ground motions are region-specific since they are constructed based on the average seismological characteristics estimated from a large number of data recorded at the region of interest. Using the created database, a suite of GMPEs is developed for CENA. Finally, proposed GMPEs will be validated against observed earthquake ground motions and against GMPEs previously developed for CENA.