Limit analysis on reinforced concrete containment of nuclear power plant

In this paper, the limit load of reinforced concrete containnent of Qinshan Nuclear Power Plant is evaluated by two different methods. One is the complete nolinear analysis, which is developed by means of FEH based on a nine node layered isoparametric shell element. Governing equations are derived by using update Lagrangian formulation to describe the geometric nonlinearities. The material nonlinearities of the concrete after cracking is considered include the nonlinearities caused by the crack propagation, the inelastic response in compression, the effect of aggregate interlocking and tension stiffening. In numerical analyses, the alternate load increment iteration and modified arc-length method are employed. The another one approach follows from the two fundamental theorems of limit analysis, The significance of which lies precisely in providing lower bound and upper bound to the colIape load.