Effect of Different Prestressed Conditions on Seismic Response of Nuclear Containment Structure under Ultimate Safety Ground Motion

In order to study the influence of prestressed conditions of concrete structure on the seismic response of the nuclear containment structure under ultimate safety ground motion, in this paper, only three prestressed conditions, which are instantaneous prestress loss, long-term prestress loss and uniform distribution of prestress after duct grouting, and the no prestressed condition are considered, and then the nonlinear time history analysis of the seismic response of the nuclear containment structure is conducted by establishing their refined finite element models. The simulation results show that for the no prestressed condition, the containment structure has a large number of cracks running through the thickness of the section in the weak seismic position under ultimate safety ground motion, and the structure basically enters the state of functional failure; while the whole containment structure is in an elastic state under the three prestressed conditions. However, cracks occur in the main opening areas of the containment, and a certain number of tension cracks are generated at the bottom of the containment body under the condition of uniform prestress distribution. The research shows that the prestressed concrete structure can significantly improve the seismic capacity of the nuclear containment structure, but it should be paid attention to the adverse impact of the uniform prestress distribution that may occur after the duct grouting on the seismic safety performance of the nuclear containment structure in design. The research results can provide guidance for the rational use of the seismic advantages of prestressed concrete in the design of nuclear containment structure.