Mining Publication: Stress Measurement of a Jointed Rock Mass During Drift Development
Original creation date: September 1999
Authors: JC Johnson, MK Larson, TM Brady, JK Whyatt, RB Langston, H Kirsten
NIOSHTIC2 Number: 20028186
In T.O. Hagan (ed). SARES 99: Second Southern African Rock Engineering Symposium. Implementing Rock Engineering Knowledge. Johannesburg, S. Africa, September 13-15, 1999. Portugal: International Society of Rock Mechanics, Sep 1999; :94-101
An experiment is described in which hollow inclusion cells (HICells) were used to measure stress in a jointed rock mass during drift development at the Stillwater Mine, Nye, MT, USA. Two HICells were installed in the footwall approximately two drift widths ahead of the face. One HICell was overcored and then immediately tested in a biaxial chamber. The other HICell was left in place and monitored as the drift was excavated in three advances, each one-half the width of the drift. Strains were recorded hourly by a datalogger. Results show that there was little stress change during the first and second drift advances, but that a large stress change occurred after the third advance. The measurements also showed that the in situ principal stress directions lined up with regional geologic structures. Stress changes during face advance were likely caused by deformation along localized joint sets and inelastic deformation near the face.
NIOSHTIC2 Number: 20028186
In T.O. Hagan (ed). SARES 99: Second Southern African Rock Engineering Symposium. Implementing Rock Engineering Knowledge. Johannesburg, S. Africa, September 13-15, 1999. Portugal: International Society of Rock Mechanics, Sep 1999; :94-101