Progressive collapse simulation of building structures considering residual bearing capacity of columns after blasting demolition

In the process of blasting demolition, damaged columns retain a certain level of residual bearing capacity, which significantly influences the progressive collapse behavior of structures. To account for this residual capacity in numerical simulations while maintaining computational efficiency, a modified alternate path method (M-APM) based on the conventional alternate path method (APM) is proposed. In M-APM, equivalent resistance is applied at the cross sections of the damaged columns to simulate their residual bearing contribution. Numerical results demonstrate that the M-APM provides a more accurate representation of the collapse response during blasting demolition, showing better agreement with expected structural behavior in terms of global damage distribution, plastic hinge formation, and collapse mechanisms. The proposed M-APM offers a reliable and efficient approach for simulating the progressive collapse of structures under blasting demolition.