Stability of Tailings Dam Constructed by both Upstream and Centerline Methods

In China, there are more than 12,000 tailings ponds, and the number is still growing. With the rapidly increasing number of tailings ponds, the safety issue has drawn more and more attention by governments and local communities. The design and construction of each tailings pond must meet the specific requirements of a particular mining project and the changing conditions with time. This paper presents a case study of the Dahongshan Longdu tailings pond which combined upstream and centerline methods for dam construction. The Dahongshan Copper Mine and Iron Mine were facing a challenge of the disposal of increased production of tailings. The current upstream method of dam construction could no longer guarantee its safety. Therefore, the original design of tailings pond should be revised for the safety of the tailings pond. This tailings dam used centerline method for subsequent construction after total height of this dam was constructed up to 100 m by upstream method. This tailings pond initially used upstream method for the dam construction. To pile up the increased production of tailings, the dam construction method was switched to centerline method after dam height of 100 m. Numerical simulation was performed to analyze the seepage and displacement fields, stability and storage capability of the tailings dams constructed by upstream and mixed methods, respectively. Through the simulated results, the mixed method was demonstrated to be more beneficial to the practical safety management of this tailings pond than the upstream method.