原位置試験・室内試験・原位置挙動による堆積軟岩の変形特性

抄録

A 50m deep shaft, an adit and a tunnel were excavated for research purpose in a sedimentary soft rock deposit (mudstone). The stiffness of the mudstone was back-calculated from the field data as a function of strain, which was compared with that obtained from the field and laboratory stress strain tests. The Young's modulus values were very similar to each other when the strain level-dependency of stiffness (or shear stress-dependency) without incorporating the effect of discontinuity evaluated by the triaxial compression tests is considered.