2021 Volume 77 Issue 2 Pages I_29-I_43
The objective of this research is to investigate the hydro-mechanical behavior of rock mass around the shaft in the Horonobe Underground Research Laboratory (URL). The long-term monitoring has been carried out by optical sensors installed below 350m depth of the shaft in the Horonobe URL. From the measurement results, AE activity occurred frequently within 1.5 m from the shaft wall. In this area, significant increase in pore pressure was measured several times as advance of the excavation, then decrease to almost 0 MPa after the excavation. Therefore, the area from the wall surface to a depth of 1.5 m was evaluated as EDZ (Excavation damaged zoon). This EDZ was consistent with the in-situ permeability test results and numerical analysis results.
