Numerical Study of Progressive Collapse in Intermediate Moment Resisting Reinforced Concrete buildings

The progressive collapse in buildings is one of the topics that has been attended by many civil engineers in recent years. In this regard, and in the present study, the progressive collapse in RC structures with Intermediate Moment Resisting Reinforced Concrete buildings has been investigated. For this purpose, the progressive collapse potential in a 10-story RC building with Intermediate Moment Resisting Reinforced Concrete buildings, which was designed according to the national regulations of Iran's building against earthquake, was evaluated using an alternative load path method and UFC code. The variable parameters examined include the removal of columns in the height of the building (first and fifth floors) and the position of the column removal in the plan (without removing the column, removing the corners of the outer frame, removing the middle column from the outer frame and removing the middle column from the Exterior frame). In this way, seven concrete reinforced buildings were evaluated against progressive collapse. In order to simulate and evaluate buildings against progressive collapse, the finite element method was used with ABAQUS software. Also, the accuracy of the finite element method used in simulating RC structures was performed by modeling an RC frame, which was evaluated in a laboratory study, and a suitable adaptation was observed. The most important results show that the ratio of the axial force variations before and after the removal of the member, in cases where the column is removed from the first floor, than the cases in which the column in the fifth class was deleted, the highest and lowest values were increased by 70% and 42%, respectively. Therefore, the removal of a column on the first floor, rather than the removal of a column in higher classes, can show a more critical behavior in the final structure response to progressive collapse. On the other hand, according to the results, it is possible to state that reinforced concrete structures that are resistant to earthquakes, if they are of high sensitivity, should be investigated against progressive defects in order to be able to withstand abnormal loads which affects the function of the building, has the necessary resistance.