Abstract
Engineered cavities in rock formations are often part of an underground transportation infrastructure. Three measures of roof stability in such cavities are discussed: the stability number, the factor of safety, and the support pressure needed to prevent cavity roof failure in weak rock. The stability number is a dimensionless combination of the rock properties and the size of the cavity when roof failure becomes imminent. While there exists substantial experience in application of the stability number and the factor of safety to soil structures, their use to define the safety of rock structures is intricate. This is because the strength envelope for rocks is a non-linear function of the mean stress. The specific function used in the analysis is the Hoek-Brown failure criterion. The kinematic approach of limit analysis is used, and the results are presented in charts. All measures of stability are strongly dependent on the Geological Strength Index, and, to a lesser degree, on other parameters in the Hoek-Brown failure criterion.
Original language | English |
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Pages (from-to) | 629-638 |
Number of pages | 10 |
Journal | Geotechnical Special Publication |
Volume | 2022-March |
Issue number | GSP 332 |
DOIs | |
State | Published - 2022 |
Event | 2022 GeoCongress: State of the Art and Practice in Geotechnical Engineering - Deep Foundations, Earth Retention, and Underground Construction - Charlotte, United States Duration: 20 Mar 2022 → 23 Mar 2022 |