Mining Publication: Ground Failures in Coal Mines with Weak Roof

Coal miners who work and travel under supported roof expect to be protected from rock falls. However, rock fall accidents and injuries continue to occur in coal mines that have been supported according to the roof control plan. Experience at coal mines with large numbers of falls indicates that many have weak roof. Control of this roof may require additional ground control measures. An understanding of the geologic and stress conditions which lead to roof falls is necessary to assess the risk of failure and to design roof reinforcement to improve stability. Six common roof fall types, with attached field examples, are described. Roof support practices for each fall type are also described.