In order to study the stressing characteristic of spiral case structure with different embedding types and to ascertain the application feasibility in large-scale hydropower station powerhouse,the spiral case embedded with cushion layer and the complete bearing spiral case were analyzed using three-dimensional nonlinear finite element method(FEM) from an actual project.

By means of the ABAQUS software,a nonlinear finite element method(FEM) based on damage theory was used in structural calculations of the complete bearing spiral case of a large-scale hydropower station.

Nonlinear dynamic responses of complete bearing spiral case under the action of pulsation pressure;

Three-dimensional nonlinear finite element static calculation of complete bearing spiral case;

Among the three forms mentioned above, the directly embedded spiral case has a good perspective in application with the characteristics of convenient construction and steady working performance of the hydraulic turbine generator unit.

The rationality of the contact model was proved by the simulated results of the practical directly-embedded spiral case.

The stress and strain of a directly-embedded spiral case in the Three Gorges Project was analyzed by using 3-D nonlinear FEM.

Compared with the bedding laying method and the pressure retaining laying method,the spiral casing direct laying method can make reinforced concrete to bear higher hydraulic pressure.