Restoring force characteristics of reactor buildings based on load tests and numerical analysis, 1

In this paper, load displacement relationship models are proposed for reinforced concrete shear walls of nuclear reactor buildings based on the results obtained from (1) load tests using reduced scale models, and (2) numerical model tests using non-linear FEM analysis. Establishing a feasible earthquake-resistant design against large earthquake is very important, especially in Japan. It is necessary, therefore, to determine the elastic and plastic range characteristics of reactor buildings. The relationships between lateral load and lateral displacement are idealized with hysteresis loops and envelope curves which envelope apices of loops. Lateral displacement consists of shear and flexural displacement. In the case of reduced scale models, flexural displacement moreover consists of rotational displacement at the base. After careful consideration of the results of thirty-four reduced model tests and eighteen numerical model tests using non-linear FEM analysis, equations for calculating τ ∼ γ envelope curves were proposed. The computed envelope curves showed good agreement with experiments which were conducted not only by the authors but also other investigators. (author)