The management of mine waste dumps has historically been assigned mainly to the on-site mining operations. In recent years, focus has turned to a more scientific approach to waste rock dump management and the auditing of these manmade structures.
A risk-based classification study of mine waste dumps that was carried out by British Columbia in 1992 identified certain technical issues that would remain unsolved, particularly where pore water pressure developed in foundation materials, or poor quality fine-grained waste becomes saturated. Both of these above factors are adversely influenced by high dumping rates and dump face heights.
Designs for proposed new dumps should include detailed stability assessments for each stage of development, taking into account the variations in rock quality and the rate of dumping. Possible modes of failure should be rigorously evaluated.
A-risk based conceptual evaluation system to determine the likelihood of waste dump slopes being unstable was developed to quantify the risk. The proposed methodology established requirements for the scope of waste dump stability investigation by considering the following elements:
- Site conditions
- Design criteria
- Monitoring requirements
- Construction guidelines.
This methodology or risk-based design procedure is continuously developing to encompass the changing on site requirements for large mining operations that often span an extensive mining lease area.
A common-sense approach to evaluating and determining the risks associated with a particular waste rock dump or stockpile is used on many mining operations. This paper documents some of the procedures and approaches utilized for a basalt waste dump life-of-mine design analysis.
