الفهرس | Only 14 pages are availabe for public view |
Abstract This research focuses on increasing both the strength and stiffness of the existing skewed bridge by adding a replaceable structural steel element to a RC bridge bent, which is widely known as buckling restrained braces (BRB). The concerned bridges in this study are designed in accordance with the previous version of the Egyptian standards. These bridges are retrofitted using buckling restrained braces (BRB) to increase their strength and stiffness to fulfill the requirement of the most recent seismic provisions. A parametric study is developed to achieve this target. First, numerical models similar to the case studies presented in this research are validated by comparing their outcomes to previously published corresponding results. An acceptable match between both results is found. Next, a parametric study is proposed introducing key parameters, such as skew angles, and bridge heights. Nonlinear Pushover and Nonlinear Time-History analyses were carried out on both existing and retrofitted bridges to assess the contribution of the seismic behavior of these bridges. Moreover, fragility analysis is performed on previously mentioned bridges to assess the benefits of using BRB in reducing the probability of damage occurring due to seismic action. It has been found that seismic energy and drift have been reduced due to the hysteretic behavior of the BRB to a value up to 35% and 45% respectively. Moreover, fragility curves considering damage states: immediate occupancy (I.O), Life Safety (L.S), and Near Collapse (N.C) indicated an improved response up to 50, 63, and 71%. |