In 1998 Takiguchi et al. reported the interesting test results of the R/C columns. They gave large deformation to the columns until the columns lay down on the basement. We evaluated the test results and proposed the force-deformation relation model presenting stiffness degrading and bearing force degrading, for ductile R/C columns based on the test results. And we discussed the behavior of basic building models in large deformation under severe earthquake, by using extended distinct element method with the proposed model.
