Abstract: To meliorate structural robustness, a type of improved bolted connection details is proposed on the basis of the conventional RHS column joint with through diaphragm. With a view to material fracture and the path tracking after fracture, the numerical results indicate that the bolted connection details can enhance the vertical deformation capacity of the beam-column assemblies before the force transmission failure at the bottom of a connection region, which is conductive to the development of catenary action by axial forces in the beams. For that reason, the beam-column assemblies can provide greater vertical carrying capacity and the bolted connection details can be used in designing structures against progressive collapse.