| The 2010 edition of ASCE-7 (ASCE 7-10, Minimum Design Loads for Buildings and Other Structures) introduces risk-targeted spectral acceleration values for the estimation of seismic design loads. In this study, a 20-story steel moment resisting frame structure located in Century City, CA is designed based on ASCE 7-10 and a probabilistic seismic collapse assessment is conducted. The main goals are to: (a) evaluate whether the design of a typical steel moment-frame structure based on risk-targeted spectral accelerations fulfills the target design collapse level of one percent probability of collapse in 50 years, and (b) quantify and understand the collapse potential of a tall steel structure design based on the most current U.S. seismic code provisions. The probability of collapse is estimated for two sets of 104 and 224 recorded ground motions, respectively. An evaluation of the results demonstrates that for this structure the code-prescribed collapse performance target is reasonably met. |
