Application of numerical simulation to estimate the stability of adit constructed by contour blasting method at Vi Kem copper mine

Abstract

Drilling and blasting are the primary methods to break up rocks and extract minerals in open-pit and underground mining. The effectiveness of the contour blasting method in creating suitable excavation boundaries, reducing overbreak, and improving rock mass stability around excavation boundaries has been proven in underground mining construction. However, this method is rarely applied in ore mining in Vietnam and is mostly experimental. The Vi Kem copper mine has implemented the contour blasting method using detonating cords to load the blast holes at the contour of the adit. The results have shown significant improvements such as reduced excess cross-section excavation (overbreak), and smoother and flatter at the adit boundaries. This paper utilizes a numerical model to estimate the stability of the adit after implementing the contour blasting method. The results indicated that the rock mass has a small displacement and increased stability using the contour blasting method compared to the adit excavated using the previous differential blasting method.