Copyright (c) 2009 All rights reserved. http://works.bepress.com/chadwell Recent documents in Charles Chadwell en-us Wed, 07 Oct 2009 10:38:17 PDT 3600 http://works.bepress.com/chadwell/2 http://works.bepress.com/chadwell/2 Mon, 10 Nov 2008 15:38:39 PST A strong earthquake of magnitude 6.0 (Mw) struck the Central Coast of California at 10:15:24 AM PST (17:15:24 UTC) on Tuesday, September 28, 2004. The epicenter (Figure 1) was 11 km (7 mile) SSE of Parkfield, at a depth of approximately 8 km (5 mile). The main shock was followed by a strong aftershock of magnitude 5.0 roughly four minutes later. As expected, numerous smaller aftershocks continue to strike to epicentral region. At the time of this report, no injuries have been reported and the damage is light, mostly limited to nonstructural damage. This preliminary report presents basic information on the epicenter location, intensity of shaking, and performance of structures in the epicentral region. Rakesh K. Goel http://works.bepress.com/chadwell/1 http://works.bepress.com/chadwell/1 Mon, 10 Nov 2008 15:38:35 PST This paper evaluates current Nonlinear Static Procedures (NSPs) specified in the FEMA- 356, ASCE-41, ATC-40, and FEMA-440 documents using strong-motion data from reinforcedconcrete buildings. For this purpose, peak roof (or target node) displacements estimated from the NSPs are compared with the value derived from recorded motions. It is shown that: (1) the NSPs either overestimate or underestimate the peak roof displacement for several of the buildings considered in this investigation; (2) the ASCE-41 Coefficient Method (CM), which is based on recent improvements to the FEMA-356 CM suggested in FEMA-440 document, does not necessarily provide better estimate of roof displacement; and (3) the improved FEMA-440 Capacity Spectrum Method (CSM) generally provides better estimates of peak roof displacements compared to the ATC-40 CSM. However, there is no conclusive evidence of either the CM procedures (FEMA-356 or ASCE-41) or the CSM procedure (ATC-40 or FEMA- 440) leading to better estimate of the peak roof displacement when compared with the value derived from recorded motions. Rakesh K. Goel