Tailings disposal

Two-Dimensional Large Strain Consolidation Prediction and Incrementally Deposited Tailings [1.72 MB]

Because of the expected high cost of embankment raising under the current tailings disposal strategy at a mine in NSW, Australia, FLAC analyses have been undertaken to study the strength gain due to consolidation in the Stage 1 dam. The problem is summed up as a two-dimensional consolidation procedure with incremental construction of the consolidating medium. The numerical modelling allowed porosity and permeability to be a function of accumulated volumetric strain, the drained modulus to be a function of depth of tailings and the undrained shear strength to be a function of the vertical effective stress. These procedures are implemented by means of a FISH function. Different modelling approaches have been carried out and compared. The results from the analyses indicate that the high rate of filling of the reservoir will preclude sufficient strength gain of the tailings to allow upstream construction as presently planned.

By C Dai & Philip J N PellS