Influence of waste rock dump placement on the geomechanical state of underground mine workings

Abstract

This paper is devoted to assessing the influence of waste rock surface dumps on the geomechanical state of underground mine workings. The conditions of the Pivdenno-Bilozerskyi high-grade iron ore field are chosen as the research object. To study the influence of dump placement and the depth of mine working on the mass stress state on the contour of sublevel drifts, a numerical modeling methodology based on the SolidWorks software package has been developed. This methodology involves the substantiation of the elements and properties of the geomechanical model, as well as the calculation scheme. Polynomial patterns of changing stress value in the hanging wall drift sides have been determined in the depth intervals of 440–740 m depending on the distance of the dump to the geometric center of the stope chamber. It has been revealed that the degree of the waste rock dump influence on the stress state gradually decreases with depth. It has been found that the maximum degree of the waste rock dump influence is observed on the upper horizons. When the waste rock dump is located above the geometric center of the future stope chamber that the stress value on the contour of the hanging wall drift can increase up to 10% compared to the absence of a dump on the earth’s surface. The research results are important for designing stable parameters for supporting sublevel drifts in difficult conditions of occurrence of the hanging wall rocks.