Evaluation of seismic site factors in the Mississippi Embayment. II. Probabilistic seismic hazard analysis with nonlinear site effects

✍ Scribed by Duhee Park; Youssef M.A. Hashash

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 713 KB
• Volume: 25
• Category: Article
• ISSN: 0267-7261
• DOI: 10.1016/j.soildyn.2004.10.003

✦ Synopsis

An integrated probabilistic seismic hazard analysis procedure that incorporates nonlinear site effects, PSHA-NL, is developed and used to characterize the influence of thick deposits of the upper Mississippi Embayment (ME) on seismic site coefficients. PSHA-NL follows the methodology of the 2002 USGS hazard maps and generates a compatible set of ground motion records. The motions are propagated using nonlinear and equivalent linear site response analyses and ME properties developed in a companion paper and used to derive surface uniform hazard response spectra. A set of generic site coefficients are derived and summarized in a format similar to NEHRP site coefficients, with an added dimension of ME deposits thickness to the Paleozoic rock, a physically meaningful impedance boundary. These coefficients compare well with NEHRP site coefficients for 30 m profiles. For thicker soil profiles, developed site coefficients are lower at short periods and higher at long periods than NEHRP site coefficients.