Coupled Finite Element - Scaled Boundary Finite Element Method for Transient Analysis of Dam-Reservoir Interaction

The scaled boundary finite element method (SBFEM) was extended to solve dam-reservoir interaction problems in the time domain, where dams were flexible and the fluid in reservoir was semi-infinite and compressible. Transient responses of dam-reservoir systems subjected to horizontal ground motions were analyzed based on the SBFEM and finite element method (FEM) coupling method. A dam was modeled by FEM, while the whole fluid in reservoir was modeled by the SBFEM alone or a combination of FEM and SBFEM. Two benchmark examples were considered to check the accuracy of the SBFEM-FEM coupling method. For a vertical dam-reservoir system, the semi-infinite fluid with a uniform cross section was modeled by the SBFEM alone. For non-vertical dam-reservoir systems, the fluid was divided into a near-field FEM domain and a far-field SBFEM domain. The geometry of near field is arbitrary, and the far field is a semi-infinite prism. Their numerical results obtained through the presented method were compared with those from analytical or substructure methods and good agreements were found.