ABSTRACT
The U. S. Department of the Interior’s Bureau of Mines has developed MULSIM/BM, an improved computer program using the boundary element approach for geomechanical analysis of mine plans in single or multiple coal seams. This paper discusses the improved program capabilities and presents an example application of MULSIM/BM to analyze a two-lift longwall mining situation where the upper and lower coal seams are separated by a 10-ft rock parting. Assuming completion of mining in two advancing long-wall panels, with double-entry gate roads, options are analyzed for locating a double-entry system for the first lower-panel headgate entries for retreat longwall mining. The initial analysis uses a one-seam model to obtain rock-mass stress distributions for a plane corresponding to the location of the lower seam. A selected configuration for the lower-seam panel entries is then analyzed as a full two-seam problem.
