Biaxial-loading Measurement for Mine-pillar Stability Evaluation - Case Studies.
Soc Min Eng AIME Littleton Colorado 1986 :142-151
This paper presents three case studies in which the biaxial loading was measured to evaluate the stability of longwall chain pillars. Integrity factor, defined as the ratio of the total pillar strength to the total pillar load, is the criterion for stability. The total pillar load is derived directly from the in situ measurement of vertical pressures. The total pillar strength is derived from the situ measurement of horizontal pressures and the confined compressive strengths of pillar material as determined in laboratory tests. Horizontal and vertical pressures in the pillar were measured with the Bureau of Mines, U.S. Department of the Interior, hydraulic borehole pressure cells.
Soc. Min. Eng. AIME, Littleton, Co, 1986, PP. 142-151