Abstract: To develop a two-layer prestressed long-span subway station， a nonlinear seismic numerical simulation of the soil-subway interaction system was conducted， applying the plastic-damage constitutive model to describe the nonlinear and fatigue characteristics of concrete under cyclic loading and taking into account the structural damping and initial stress of the soil-structure interaction system due to the gravity and prestress of reinforced concrete. The destruction process， destruction forms and destruction locations were analyzed after the simulation. The results indicated that the dynamic shear stress concentrates in the external bottom of side walls near to the baseboard， then the mid-span and the upper root of the top board and level board， which can spread fast and even form penetrated cracks in some parts. The dynamic tensile and compression damage emerges easily in the vertical direction of side walls near to the baseboard， and it also emerges easily in the horizontal direction of the top board and level board. The dynamic shear stress concentrates in turn in the junction between side walls and the top board as well as the baseboard. Side walls near to the baseboard and the root of the top board are key parts of a frame for safety where failure tends to occur earlier.

Key words: prestress, long-span subway station structure, seismic damage, numerical simulation, plastic-damage constitutive model