Residual axial compression capacity of localized blast-damaged RC columns

The risks associated with suitcase bombs are of serious concern because they can be easily handled and placed within close proximity of key structural components of building structures. The most common failure mode of the structures subjected to blast loads from satchel and suitcase bombs is progressive collapse. High-fidelity physics based computer program, LS-DYNA is utilized in this study to provide numerical simulations of the dynamic response and residual axial capacity of reinforced concrete (RC) columns subjected to blast loads. Field tests using near-field explosive charge were conducted on two RC column specimens. The test results were compared with the analytical results to validate the finite element model. An extensive parametric study was conducted to investigate the relationship between residual axial capacity and structural and loading parameters such as material strength, column detail and blast conditions. Two empirical equations were derived through a multivariable regression analysis in terms of the various parameters to predict the residual capacity index based on a non-dimensional column dimension parameter (ωTNT). According to the proposed equations, the residual capacity index can be determined and compared with a service axial load index.