EFFECT OF THE BUILDING HEIGHT ONPROGRESSIVE COLLAPSE

Progressive collapse is defined as extension of initial collapse, from a part of structure to another one that may result in destruction of structure. Possible risks and abnormal loads that cause progressive collapse are as follows: aircraft collision, design or construction error, firing, gas explosion, random overload, vehicles contusion, bomb blast and etc. such phenomenon are not consider in designing typical structure, since possibility of occurring these risks is very low. However, they should be regarded in very important or special structures. In this research, effect of the building height on progressive collapse is studied. For this purpose, steel moment resisting structures designed for high seismicity zone areas, with four, eight and twelve- stories are considered and their progressive collapse are studied and compared. Results indicate that the potential of progressive collapse decreases by increasing building height. The main reason is increasing structure indeterminate degree, and catenary action of members.