[2M09-11] Numerical Simulation 1

2:45 PM - 3:00 PM JST(5:45 AM - 6:00 AM UTC)

[2M09] A study on the model validation of groundwater flow and mass transport for fractured rock masses(1) Effects of the modeling uncertainty on the groundwater flow characteristics

*Masayuki Ishibashi¹, Hironori O², Taichi Esaki¹, Yoichi Tagawa¹, Tadashi Namikawa¹, Koji Hane¹, Hiromitsu Saegusa², Kesuke Ishida², Atsushi Sawada³ (1. KAJIMA, 2. NUMO, 3. JAEA)

Keywords:

Fractured rock masses,Heterogeneity,Modeling uncertainty,groundwater flow characteristics,Particle tracking analysis

NUMO has been developing a hydrogeological model to describe the geometry and spatial distribution of fractures and permeability in fractured rock mass, along with their heterogeneity, and a methodology to validate the results of groundwater flow and mass transport analysis using the hydrogeological model. In order to validate the model, it is important to evaluate the uncertainties inherent in the model. Therefore, several hydrogeological models that can be assumed due to uncertainties were constructed and groundwater flow and advection dispersion analyses were conducted using the investigation data obtained at the Mizunami Underground Research Laboratory (MIU) as a case study. Specifically, in order to investigate the relationship between the heterogeneous distribution of fractures that contribute to the permeability of the rock mass and the groundwater migration characteristics after tunnel closure, particle tracking line analyses were conducted on several hydrogeological models constructed, and the effects of the uncertainties in modeling and analysis on them were discussed.