Analysis of entry roof failure and falls at Springvale Colliery
- Cyprus Australia Coal Company, North Sydney, New South Wales (Australia)
- Cyprus Amax Coal Company, Craig, CO (United States)
- Cyprus Amax Coal Company, Waynesburg, PA (United States)
High horizontal stresses and shear failure have been considered the major reasons that cause entry roof failure and falls for underground mining. Therefore, reorientation of the current mining systems or layouts or using angular crosscuts in mains or gate entries becomes more popular if a greater than normal horizontal stress is measured. However, reorientation of the current mining systems or layouts is always expensive and use of the angular crosscuts may weaken the pillar structure at comers. Therefore, cautions must be taken before any decision related to reorientation of the current mining systems or layouts or use of angular crosscuts is going to be made. In order to prevent entry roof failure and falls, the following two issues must be carefully examined and fully understood: (1) Which one, shear stress or tensile stress, is going to be blamed for entry roof failure? (2) Which one, horizontal stress, vertical stress, or local geological weakness plays a major role in entry roof failure and falls? This paper analyzes the mechanisms of entry roof failure and falls for underground mining in general, examines the roof fall history at Springvale Colliery, and proposes the means of preventing roof failure and controlling roof falls for Spingvale Colliery in particular.
- OSTI ID:
- 405574
- Report Number(s):
- CONF-9608121--
- Country of Publication:
- United States
- Language:
- English
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