Volume 5, Issue 1/2 (March 1982)
A Low Cost Stressmeter for Measuring Complete Stress Changes in Underground Mining
A stressmeter consisting of a thick steel pipe with a central partition on which a wire-resistance strain rosette gage is mounted was proposed and examined. Linear relations between applied stresses and the induced strains at the center of the partition were obtained under different loading conditions. The linear relationship is a practical necessity in monitoring stress changes. Results of three-dimensional finite element simulation compared favorably with those of laboratory calibration. Ratios of the Young's modulus of steel to the Young's modulus of rock or resin or both were found to be the dominating factor in determining the sensitivity of the stressmeter. The stressmeter is more sensitive in soft rock, such as coal, than in hard rock, such as sandstone.