Numerical investigation of crack initiation behavior in rock masses using a two-dimensional tunnel excavation model incorporating damage mechanics

Kawata, Kento*; Ogata, Sho*; Aoyagi, Kazuhei  ; Ozaki, Yusuke ; Iwai, Hiromasa*; Yasuhara, Hideaki*

In the deep geological disposal of High-Level Waste, it is essential to understand the fracturing behavior of the rock mass surrounding the disposal tunnel due to excavation for assessing the safety of the repository. In this study, 2D tunnel excavation analysis models based on damage theory were developed and were applied to an in-situ tunnel excavation conducted at Horonobe Underground Research Laboratory. The results of the analysis were then compared with in-situ data available on the purpose of validation. As a result, 18 different analysis models were constructed by changing model parameters, and two models that exhibited the best agreement with the measured data were proposed.