Study On Earthquake Damage Mechanism And Structure Selection Of Prestressed Large-span Subway Station

At present, the upsurge of urban subway construction has arrived in our country. Subway is the medicine to relieve urban traffic. Double three-span column subway station structure is the most common type. However, with the resolve of prestressed technology in large underground space, no column large-Span prestressed subway station structure has become a form of subway construction design. On the other hand, as the area of people concentrated, once the subway station damage even cause huge economic losses, and the repair of underground structures cost much money, which full of many difficulties. So, it is important to study the No column on long-span prestressed subway station performance in earthquake which full of theoretical significance and application value.To develop two-layer prestressed long-span subway station, the nonlinear seismic numerical simulation of soil-subway station interaction system is conducted, using the plastic-damage constitutive model to describe nonlinear characteristics of concrete under cyclic loading, considering the structural damping and the initial stress of soil-structure interaction system due to the gravity and prestress of reinforced concrete, using viscous-spring boundary. Then the key parts of the frame were got. The main contents are as follows:First, Soil constitutive, concrete action plastic damage constitutive model and soil structure contact approach were described.Second, Boundary conditions for the analysis of dynamic problems currently fixed boundary, viscous boundary, unlimited cell boundaries, viscoelastic boundary were studied, dynamic characteristics under different boundary conditions of free field were compared. dynamic characteristics of different venues freely fluctuating input are analyzed, and determine a reasonable boundary conditions and seismic wave input method.Third, the nonlinear seismic numerical simulation of soil-subway station interaction system is conducted, using the plastic-damage constitutive model to describe nonlinear characteristics of concrete under cyclic loading, considering the structural damping and the initial stress of soil-structure interaction system due to the gravity and prestress of reinforced concrete, using viscous-spring boundary.. Destruction process, destruction forms and destruction location were analyzed after the simulation. And the reasonable explanation were given.Fourth, Ensuring safety and reliability, a double column three-span subway station structure were redesign to be no-column large-span subway station. seismic response were analyzed. The performance of two type large span station structure and the double column station under earthquake were analyzed. Acceleration response, resulting in the development of cracks, stress response and other factors under different positions were compared. the seismic performance of large-span prestressed subway station are comprehensive evaluated.