Estimation of Parting Stability and Support Requirements During Depillaring in Two Contiguous Coal Seams

Bord and pillar is the most common and traditional method of coal extraction in India. This method accounts for over 95% of coal production from underground mines. Multiple seam coal production from in India, accounts for approximately 10% of the underground coal mines. In India, there are number of cases of parting failures in mines due to instability of the interburden between contiguous seam workings. The factors affecting parting stability in contiguous depillaring have been identified as horizontal to vertical in situ stress ratio, width of splits/slices, rock mass rating, compressive strength of parting, thickness of parting and relative position of the upper and lower production faces. Series of FLAC models were run to cover all these variables to derive empirical equations for parting stability and support requirements in contiguous seams operations in Indian coal fields. Two case studies are used to validate the new empirical equations for parting stability and support requirements.