ABSTRACT
In complex geomining conditions involving multiple seams meticulous planning is utmost requirement. This chapter summarizes the design methodology to be adopted for successful planning of a highwall mining project, and its safe operating procedures to ensure stability and productivity. These guidelines are prepared based on experience gained over the past couple of decades of designing highwall mining and field implementation in various countries such as U.S., Australia and India. The guidelines include recommended procedures for web pillar strength estimation, load on web pillars, safety factor determination and recommended safety factor ranges for ensuring surface integrity. The chapter also incorporates the design philosophy and extraction sequence for multiple seams, when they are in close proximity. To avoid major ground control issues, the norms to be followed for highwall stability evaluation, identification of crucial geological features, highwall inspection and monitoring are summarized. The importance of entry span stability and practical methods to evaluate the same are presented. Finally all pertinent operational guidelines and precautions to be undertaken for safe highwall mining operations are enlisted.
