Spatial nonlinear simulation analysis of progressive collapse resistance of R.C. frame structure under different seismic precautionary

Abstract

Based on the 3D virtual laminated element and considering the beam-slab-column collaboration, this paper conducts the nonlinear infinite laminated element analysis of three reinforced concrete (R. C.) space frame structural models with different seismic precautionary, respectively, after single-column failure and collapse calculation analysis and method verification of a two-bay and four-floor R. C. space frame. Analysis results show that: 1) with the increase of the seismic precautionary intensity, the space stiffness of the frame structure when collapsing as a whole increases, and the collapse mode transfers from the “slow changing” to the “abrupt changing;” 2) the higher the seismic precautionary intensity is, the stronger the vertical progressive collapse resistance capability of the structure is; 3) the floorslab membrane effect can delay the appearance of the beam’s catenary effect, but enhance the framed beam-to-floorslab membrane stress mechanism and the catenoid mechanism; the slab-framed beam collaboration can increase the vertical progressive collapse capability in the catenary (catenoid) period.