Span Length Effects on the Progressive Collapse Behaviour in Concrete Structures

Progressive and general collapse of structures are extremely able to cause great casualties and financial losses. Accordingly, evaluation the performance of structures after losing primary elements is of great importance to prevent the structural collapse. This paper presents the progressive collapse assessment of RC moment frames with concrete shear wall system according to different span lengths. First, story column was destroyed by removing its reaction in different scenarios. Then, performance of the structure was evaluated under this circumstance to assess the different span length effects in RC moment frames with concrete shear wall. The results indicated that the shear wall has a positive effect on preventing progressive collapse and reduces the maximum vertical displacement by 30%. It was also observed that maximum Dynamic Amplification Factor (DAF) in the building occurs with the shear wall and the minimum length of the span. However, the maximum Demand Capacity Ratio (DCR) in a critical element for a building was obtained with the longest span and without the shear wall. Therefore, it was concluded that the DCR ratio is more suitable for evaluation of the progressive collapse severity than the DAF parameter.