Abstract:Based on the improved discrete-continuum soil model, simulation of the collapse process of the Daikai station and the large deformation of the surrounding soil is performed. This paper improves the optimization model which is solved by the Lagrange multiplier method and is utilized to enforce force continuity on the coupling boundary. Then this improved model is applied to the discrete-continuum model. The continuity between the discrete and continuum domains is fulfilled by interchanging velocities and forces between them. By performing the free vibration column simulation and numerical cyclic biaxial tests, the degradation curve for the particle assembly is fully obtained and applied to the continuum model. Damage pattern obtained from the simulation is very similar to the collapsed situation of the subway station after the earthquake. Besides, from a quantitative perspective, the subway station column’s horizontal differential displacement obtained from simulation is compared with that from existed paper. It is shown that, coupled macro-micro approach can efficiently reduce particle numbers and provide a micro perspective on soil and the structure experiencing damages in the concerned zone.