Abstract: Object-oriented FEM program of underground caverns is briefly introduced with class element as representative. A program code written in VC + + is presented to simulate the stepped excavation of an underground powerhouse and to analyse the deformation. The result is consistent with that of Phase2 software. The seismic input in dealing with dynamic response is implemented through artificial boundary by using object-oriented FEM. Furthermore, the law of dynamic response of the underground powerhouse is analysed and the result shows that the response of monitoring points lags behind and the amplification factor of peak is larger than theoretical solution in the absence of cavern under the same action. On this basis, the influence of damping coefficient on the dynamic response of underground caverns by different methods is researched. The feasibility and applicability of object-oriented FEM in underground caverns are validated. The research result lays a foundation for further study on elastic-plastic behavior under dynamic load.

Key words: underground caverns, object-oriented, FEM, artificial boundary, damping