The close proximity to the New Madrid Seismic Zone and the significant population and infrastructure presents a potentially substantial risk for central U.S. cities such as Memphis, Tennessee. However, seismic provisions in currently adopted Memphis building codes for non-essential structures have a lower seismic design intensity level than the 2003 International Building Code (IBC) with broader acceptance nationally. As such, it is important to evaluate structures designed with these local seismic provisions to determine whether they will perform adequately during two different design-level earthquakes in this region. A four-story reinforced concrete (RC) moment frame with wide-module pan joists was designed according to current building codes relevant to the central U.S.: the 2003 IBC, the City of Memphis and Shelby County locally amended version of the 2003 IBC, and the 1999 Standard Building Code (SBC). Special moment frames (SMFs) were required for the IBC and SBC designs, but lower design forces in the amended IBC case study permitted an intermediate moment frame (IMF). However, the margin by which a SMF was required was very small for the SBC design. For slightly different conditions IMFs could be used. Nonlinear push-over and dynamic analyses using synthetic ground motions developed for Memphis for 2% and 10% probabilities of exceedance in 50 years were conducted for each of the three designs. The FEMA 356 recommended Basic Safety Objective (BSO) is to dually achieve Life Safety (LS) for the 10% in 50 years earthquake and Collapse Prevention (CP) for the 2% in 50 years earthquake. For the member-level evaluation, the SMF designs met the LS performance objective, but none of the designs met the CP performance objective or the BSO. However, the margin by which the SMF buildings exceeded CP performance was relatively small compared to that of the IMF building. Fragility curves were also developed to provide an estimate of the probability of exceeding various performance levels and quantitative performance limits. These relationships further emphasize the benefits of using an SMF as required by the IBC and, in this case, the SBC.
| Identifer | oai:union.ndltd.org:TEXASAandM/oai:repository.tamu.edu:1969.1/ETD-TAMU-1462 |
| Date | 15 May 2009 |
| Creators | Kueht, Erin |
| Contributors | Hueste, Mary Beth, Bracci, Joseph, Gardoni, Paolo, Peacock, Walter |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | thesis, text |
| Format | electronic, application/pdf, born digital |
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