Abstract:
This paper summarizes the major design methods and classification-design systems in foreign codes to resist progressive collapse. And then the alternate path (AP) method and tie force (TF) method in the progressive design for reinforced concrete (RC) frames are studied. Firstly, based on the analyzing the nonlinear dynamic AP method, the principle and design factors of the linear static AP method are analyzed, and moreover, design factors suitable for Chinese structures are suggested. Secondly, the inapplicability of the TF method in foreign codes to enhance Chinese RC frames is studied. The calculating model of foreign TF method is improved and a TF method considering space load paths is suggested. Both the linear static AP method and the TF method suggested by this paper are verified by design.