Mohammad Hossein soltani - Department of Civil Engineering, Qazvin Branch, Islamic Azad University, Qazvin ۱۴۷۷۸۹۳۸۵۵, Iran
Seyed Hooman Ghasemi - Department of Civil Engineering, Auburn University, USA

In the recent severe earthquakes, it has been seen that existence buildings have high vulnerability. It is noticeable that the earthquakes caused extensive damage in the new constructed buildings, such as extreme structural or non-structural fractures. One of the prominent issues for the seismic design of structures is to estimate the reliability from the maximum value of structure deformations when the earthquake occurs. The main goal of this research is to determine the reliability index of serviceability limit state analysis of steel structures for their lateral deflection as the controller target function under critical excitation load. This study is very valuable for the following reasons: a) Effective quantities for the analysis and design of structures is stochastic generally and having the uncertainty. So, using the probabilistic analysis of reliability, the final result near the actual is found by influence of uncertainties. b) Applying the critical excitation earthquake for loading is so good to obtain the actual results with proper confidence margin. It is because of continuous frequency contents of such earthquakes which cause the most probable response of structure is created.

reliability index, Critical Excitation, Random Variables and Uncertainty, Power Spectral Density, Serviceability Displacement