## Abstract

The rock fracture data provided by Swedish Nuclear Fuel and Waste Management Company were used to develop a 3-D stochastic fracture network model for a 30m cube of Äspö diorite located at a depth of 485 m at Äspö Hard Rock Laboratory, Sweden. This fracture network model was validated. A new procedure is developed to estimate rock block strength and deformability in three-dimensions allowing for the anisotropy and incorporating the inherently statistical fracture geometry for the selected cube. The mean rock mass strength was found to be 47% of the mean intact rock strength of 297 MPa at 485 m depth. The mean rock mass modulus was found to be 51% of the intact rock Young's modulus of 73 GPa. The rock mass Poisson's ratio was found to be 21% higher than the intact rock Poisson's ratio of 0.28. These percentages indicate the level of weakening of the rock mass due to the presence of fractures. The ratio of mean major principal rock mass strength/mean minor principal rock mass strength turned out to be 1.28. The ratio of mean major principal rock mass modulus/mean minor principal rock mass modulus turned out to be 1.21.

Original language | English (US) |
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Pages (from-to) | 313-330 |

Number of pages | 18 |

Journal | Geotechnical and Geological Engineering |

Volume | 22 |

Issue number | 3 |

DOIs | |

State | Published - Jun 8 2004 |

## Keywords

- 3-D numerical modeling
- Anisotropy
- Rock fracture network modeling
- Rock mass deformability
- Rock mass strength
- Underground rock mechanics

## ASJC Scopus subject areas

- Architecture
- Geotechnical Engineering and Engineering Geology
- Soil Science
- Geology