Numerical Analysis of Staged Construction of an Upstream Tailings Dam

A case study is presented in this paper which describes finite element analysis of staged construction of the upstream tailings dam Aitik, located in north of Sweden. The purpose of the study is to evaluate stability of the dam for current and future raisings and to strengthen the dam with optimum volume of rockfill banks on the downstream side when stability of the dam is not satisfactory during a construction stage. The finite element method was utilized to model the consolidation process and stability of the dam during the staged construction. The study has shown that stability of the dam during raisings was reduced due to build-up of excess pore pressures. Therefore, the dam was strengthened with rockfill banks on the downstream side to carry out the construction of the dam at a planned rate of raising. An optimization analysis was performed in order to reduce the volume of the rockfill necessary for stabilizing the dam. With the use of the finite element based optimization approach discussed in this paper, stability of the dams during staged construction can be enhanced by utilizing a minimum volume of rockfill banks.Godkänd; 2014; 20140527 (hmat