Determination of in-situ stress field using back-analysis approach: a case study of Jwaneng Mine

A good understanding of the mine-scale stress field is essential for the underground mining design. When the geological condition is complex, variation of local stresses can be significant, which brings difficulties for the interpretation of stress measurement data. In this case, to obtain the best-fit stress field, the back analysis approach using the detailed numerical model can be an effective methodology. This article presents a case study of the assessment of the in-situ stress field of Jwaneng Mine in Botswana. A mine-scale numerical model is built using 3DEC, in which the stratigraphy information, major faults as well as the excavation effect of the open pit are considered. The stress variation of the measurement data collected using the overcoring method from 2013 to 2019 is simulated. By using a new iteration approach based on the least square method, the best-fit mine-scale stress field is obtained. It demonstrates that the proposed approach can be effective in the determination of the mine-scale stress field with complex geological conditions.