Rock stress measurement using the compact conical-ended borehole overcoring (CCBO) technique

In this paper, the results of rock stress recently measured in Japan are discussed. Firstly, the CCBO developed by the authors is described in brief. Then, the case examples of stress measurement for rock slope and underground cavern by the CCBO are demonstrated, then the state of stress in rock slope and the design of underground powerhouse are discussed from the rock engineering viewpoint, based on the measured stress.