Assessment of the progressive collapse in the steel moment frames with L-shaped plan using sensitivity analysis

The progressive collapse of the structure refers to the development of an initial local damage. After local damage, failure extends in the structure and structural failure occurs. In progressive collapse, the element that has the greatest potential is important because strengthening this element can improve structural performance. In this paper, the position of the critical column in L-shaped plan has been checked. So, buildings with 10, 15 and 20 stories were modeled as three dimensions. In this type of plans, to determine the key elements, columns in different situations are removed and push down analysis is done. The element which has maximum of the sensitivity index is selected as a key element in the progressive collapse. Results in this paper show that in the L-shaped plan, a central column is critical in the progressive collapse.