The investigation of the effect of plan irregularities on the progressive collapse response of low to medium rise steel structures

[摘要] This research examines the effect of plan irregularities on the progressive collapse of steel structures. Firstly, 2, 3 and 5-storey steel structures, regular and irregular, located in regions with different seismic activity designed in accordance with AISC (20 I 0) and ASCE7 (20 I 0). Secondly, the effect of the four plan irregularities on the progressive collapse of braced and unbraced steel structures located in regions with different seismic activity assessed. The collapse patterns of the I4 buildings is analysed and compared under seven loading scenarios using nonlinear dynamic and static analyses. In the nonlinear dynamic analyses, node displacements above the removed columns and the additional force on the columns adjacent to them are discussed. Furthermore, the capacity of the columns is compared to determine their susceptibility to collapse. ln the nonlinear static analyses, the pushdown curve and yield load factor of the structures are obtained after column removal. The results indicate that an irregular structure designed in site class C seismic zone collapses in most of the column removal scenarios. Moreover, when comparing regular and irregular structures designed in site class E seismic zone, the demand force to capacity ratio (D/C) of the columns in the irregular structures is on average between I.5 and 2 times that of the regular ones has been discussed by Homaioon Ebrahimi et.al (20 I7). The lack of 2-storey building bearing capacity to withstand the removal of the column is lower than that of the 5-storey structure, which is due to the level of redundancy that characterises in the 5-storey structure.

[发布机构] University:University of Birmingham;Department:School of Engineering, Department of Civil Engineering

[关键词] T Technology;TA Engineering (General). Civil engineering (General)