A static loading test was carried out on a 1/3-scale concrete-filled square steel tubular column-steel beam frame (CFSTSBF)\nspecimen with 2 spans to study its progressive collapse behaviors under the middle column failure scenario using the alternate\nload path method and to examine the failure mode and load transfer and main resistance mechanisms of the residual structure.\nThen, theoretical models of the specimen, involving the whole collapse process, were developed, and the resistance and deformation\nrelationships of each model were calculated and validated with test results. The results indicated that the specimen\ncollapse process includes the elastoplastic stage, plastic stage, transfer stage, and catenary stage, the beam mechanism and catenary\nmechanism were the principal mechanisms for the structure against progressive collapse, and catenary action can significantly\nstrengthen structural resistance. The modified theoretical models with higher practical accuracy could be used to assess structural\nperformances against progressive collapse.
Loading....