Numerical investigation on progressive collapse resistance of post-tensioned precast concrete beam-column assemblies under a column-loss scenario

Post-tensioned precast concrete (PTPC) frames exhibit better seismic behavior and self-centering capability than conventional precast concrete frames, but few studies have focused on the progressive collapse performance of PTPC frames. Moreover, previous studies on the progressive collapse response of PTPC frames did not consider the development of the beam-column interface stress. In this study, a three-dimensional nonlinear finite element model (FEM) of a PTPC frame is established and validated using previous experimental results. In particular, the cohesive zone model and Coulomb friction model are used to simulate the development of normal and shear stresses at the beam-column interface. The overall response and failure modes are simulated well by this FEM. In addition, the progressive collapse mechanism of PTPC frames is elaborated and the load resistance component of the frames is analyzed. Parametric studies are performed based on the calibrated FEM. The results demonstrate that a PTPC frame is incapable of developing an effective beam flexural action to resist progressive collapse and the beam compressive arch action (CAA) makes a negative contribution to the progressive collapse resistance under large deformation. The condition of the beam-column interface has a limited effect on the tensile catenary action response of PTPC frames, yet influences the CAA response.