SIMULATION OF CONCRETE-FRAME COLLAPSE DUE TO DYNAMIC LOADING

The extended distinct-element method (EDEM) is used to construct models of multi-degrees-of-freedom systems for particles of concrete frames and to conduct a series of numerical simulations in which the particles collapsed due to seismic forces. When a concrete frame collapses, it is reduced to a pile of debris. If the debris is rejoined to form the concrete frame, the original shape is restored; i.e., the frame prior to collapse is considered to be an assembled body of concrete debris. The EDEM is a method for analyzing discontinuous bodies, but here we report on an analysis in which concrete debris is considered to contain the elements of a discontinuous body. For convenience, we assumed that the particle shape in the debris is circular and that the parts are connected by springs that satisfy the Mohr-Coulomb yield conditions. The results of our simulations are in good agreement with records of damage done by past earthquakes