Stability Evaluation of Retreating Longwall Chain Pillars With Regressive Integrity Factors.
Proc 5th Cong of the Int Soc for Rock Mech Melbourne Australia 2:E37-e40
Profiles of mining-induced loading and residual strength across a pillar vary with the position of the longwall face. The residual pillar-strength profiles can be constructed on the basis of laboratory-determined triaxial compressive strength, in which the in situ measured horizontal pressure is considered as the constraint. The vertical-loading profile can be established with the measured vertical pressures. Vertical and horizontal pillar pressures can be measured with hydraulic borehole pressure cells. Defined as the ratio of the integrated total strength to the integrated total load under the profiles, the integrity factor is proposed here as a rational parameter for evaluating chain-pillar stability.
Proc. 5th Cong. of the Int. Soc. for Rock Mech, Melbourne, Australia, V. 2, PP. E37-e40