GTC Support the Evaluation of Tailings Storage Facilities (TSF), South Africa

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There have been some failures of Tailings Storage Facilities (TSF, or tailing dams, for the permanent storage of mining waste i.e., tailing materials). To reduce the risk of tailing damp failures, especially under a dynamic load/ earthquake, it is crucial to understand the soil properties and behaviour of the tailing material. At GTC we carefully conduct a comprehensive testing program on both disturbed and undisturbed soil samples to (i) evaluate the insitu soil beneath the tailing dams, and (ii) ‘calibrate’ the soil parameters as per Norsand model (critical state soil mechanic). The main testing techniques include determination of min-max density of the tailings, particle density, PSD, triaxial consolidation test, triaxial permeability test, undrained and triaxial tests at various relative density and effective stresses, measurement of shear wave velocity using bender elements, Rowe cell tests, cyclic simple tests, and cyclic triaxial tests. One of the challenges of the tests are to track precisely (and verifiably) all the changes in sample volume (void ratio/ water flow) etc. since very early stages (sample preparation, sample set-up, saturation) to the end of the test stage. 

 

The soil parameters are used to evaluate the stability of the tailing dams and to support the monitoring of the Tailings Storage Facilities. a Digital twin (i.e. a numerical model) of specific TSFs using the soil data measured shall be developed by a researching body. The digital twin shall be analysed to determine whether the analysis results from the twin model and the insitu monitoring data are aligned. The outcoming of the study can provide early warnings if somethings may go wrong.