LAUSR

When coal excavations in two adjacent surface mines proceed in a parallel and equi-directional sequence, the stripping ratio in the overlapping section of two end walls is usually reduced; bring about remarkable economic benefits. A formula has been derived for calculating the effects of mining width on stripping ratio. An optimisation model of uncovered end-wall height and mining width is also constructed. Research results show that stripping ratio tends to decrease linearly and then increase at a slow rate as the mining width of reserves buried between adjacent surface mines (RBbASM) increases. When excavating the minimum RBbASM, there appears a stripping ratio surge. Therefore, this part of resource could not be considered for excavation. Heidaigou Surface Coal Mine (HSCM) and Ha'erwusu Surface Coal Mine (HeSCM) were selected as a case study, where the optimum uncovered end-wall height and the mining width of RBbASM are determined as 85.77 metres and 540 metres respectively. [Received: February 20, 2016; Accepted: September 5, 2016]