Three-dimensional excavation analysis based on crack tensor model at the Mizunami Underground Research Laboratory

Takayama, Yusuke  ; Sato, Toshinori  ; Sanada, Hiroyuki; Tada, Hiroyuki*; Kumasaka, Hiroo*; Fukuda, Tsuyoshi*; Kobayashi, Shinji*

In the rock mechanical study in the Mizunami Underground Research Laboratory Project, the development of the evaluation method for the excavation damaged zone due to excavation of shafts and research galleries is one of the important issues. In this study, three-dimensional excavation analysis is conducted. Crack tensor used in these analysis were measured using the data collected in wall surface observation in study tunnels such as the horizontal tunnels to a depth of 500 m. The results of analysis were compared with existing measurements at a depth of 500 m obtained using in-situ strain meters. The excavation analysis using crack tensor and initial stress obtained from the Phase I and Phase II were carried out to examine the influence of crack tensor and initial stress on the results of analysis.