Use of strain-gauged rock bolts to measure rock mass strain during drift development.
Johnson JC; Brady T; Larson M; Langston R; Kirsten H
Rock Mechanics for Industry - Proceedings of the 37th U.S. Rock Mechanics Symposium, Vail, Colorado, June 6-9, 1999. Rotterdam, Netherlands: A. A. Balkema Publishers, 1999 Jun; :497-502
An experiment is described in which instrumented rock bolts were used to measure strain in the rock mass during drift development at the Stillwater Mine, Nye, Montana, USA. Two strain-gauged rock bolts were grouted into the middle of the rib next to the face. The drift was excavated in three advances, each one-half drift wide. Strains were recorded hourly by a data logger. Results show that the average change in axial bolt strain for the first and second advance was about the same and that there was almost no change in strain after the third advance. Bending strain was observed 19 cm from the head of the bolt.
Mine-shafts; Mining-industry; Ground-stability; Ground-control; Injury-prevention; Safety-measures; Safety-research; Structural-analysis; Statistical-analysis; Accident-prevention; Accident-potential; Rock-bursts
Amadei B; Kranz RL; Scott GA; Smeallie PH
Rock Mechanics for Industry - Proceedings of the 37th U.S. Rock Mechanics Symposium, Vail, Colorado, June 6-9, 1999