Measurement of the rock strain/displacement during deep shaft excavation in crystalline rock

Hirano, Toru; Matsui, Hiroya ; Kinoshita, Harunobu

We tried to understand the amount of the total rock deformation and the feature by the strain/displacement measurement during a deep shaft excavation in crystalline rock. For this purpose, the instruments were installed in the vertical boreholes drilled along a shaft before excavation. Then strain/displacement were measured during the excavation. As a result, the large strain/displacement by blasting were measured at 1 or 6 meter far from the shaft wall, Also, the rock behavior was estimated to be elastic approximately based on comparison between measured and theoretical value. Also, damage range of the rock caused by blasting was estimated less 1 meter far from the shaft wall.