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Relating crustal deformation to stress conditions has long been a subject of interest to the geologic community as rock failure has important implications for storage and extraction of petroleum and mineral deposits, as well as sequestration efforts. The ability to relate patterns of rock deformation to stress conditions also permits geologists to better understand structural evolution. This dissertation focuses on interpreting and modeling crustal stress conditions from outcrop to regional scale associated with late Cretaceous to early Eocene deformation across the Colorado Plateau.The first part of this dissertation focuses on salt-related stress perturbations adjacent to the Salt Valley salt wall in the Paradox Basin of southern Utah. Under Late Cretaceous-early Eocene tectonic loading, the salt wall underwent active diapirism via ductile flow because of its inability to sustain differential stress due to inherent mechanical weakness. This phenomenon generated local stress perturbations from regional tectonic conditions in the rock mass adjacent to the deforming salt wall. The first two studies presented in this dissertation improve our ability to interpret and predict stress conditions and the associated rock failure in the perturbed stress environment around salt bodies under tectonic loading. This includes evidence and implications for use of a non-linear failure criterion to describe brittle rock failure, as opposed to the commonly used linear Coulomb failure criterion. The second part of this dissertation focuses on regional tectonic stress and associated Laramide deformation across the Colorado Plateau. Laramide deformation is evidenced by basement-cored uplifts bound by doubly plunging monoclinal folds. Blind basement fault geometries are estimated with trishear fault-propagation models and generalized area-depth calculations. The blind basement fault model is used as inputs into a geomechanical model to evaluate regional Laramide stress conditions respons

Slope stability hazards such as rockfall and slope failures remain a critical risk for the mining industry (Ross 2017). With globally declining ore grades across metalliferous mines (Calvo, Mudd et al. 2016), many operations are driving pits to new depths and sometimes at steeper angles. The mine permitting process in the United States is challenging, thus operators are focusing on simultaneous successive mining cuts in currently permitted deposits. The two challenges mentioned above are increasing the likelihood of slope stability hazards in the mining industry. Specifically slope steepening can increase the likelihood of slope failure, and successive and concurrent mining cuts can generate a higher potential for rockfall hazards. This is creating an additional need for controls to manage these hazards effectively. Outside of the mining industry landslides in natural and constructed slopes cause approximately 1000 fatalities per year according to data assessed between 1998 to 2017 (WHO 2023). While the overall trend of the frequency of natural landslides does not seem to be systematically increasing, there is an increasing trend of human caused events in recent years (Froude and Petley 2018). The research presented in the publications below can be applicable to civil, natural, and mined slopes, and could be used to reduce risk. It is demonstrated in the four publications below that slope monitoring is a crucial risk reduction measure in the surface mining environment. The publications below show how it can be used to inform the calibration of rockfall models and help in the development of rockfall control measures using unmanned aerial vehicles (UAV) videography and photogrammetric surveys. While it is known that slope monitoring is essential to keep miners safe in the open pit environment (Girard, Mayerle et al. 1998), the research herein provides additional guidance on developing slope monitoring systems based on risk. The articles below also demonstrate how comp

Slope failure is one of the significant risk factors in both mining and civil engineering industries due to its potential impact on productivity and safety. Although the risk can be controlled mainly through slope monitoring techniques and preventive measures, predicting the time of slope failure (TSF) remains a challenge and therefore needs improvement. To better predict slope failure, analyzing the initial signs such as rockfalls is the most important step. However, lots of current monitoring equipment can be blind to identifying individual small rockfalls. The first part of this dissertation investigates different types of slope responses to the blasting activity using a new technology developed by GroundProbe called “BlastVision.” which can detect rockfall during blasting. The second and third parts of the dissertation investigate the prediction of the TSF. Inverse velocity is the predominant method used in industry to predict the TSF. Experts agree that in addition to the rate of slope deformation, other properties such as geology, rainfall, coherence, amplitude, pore pressure, water infiltration, etc., play a significant role in predicting slope failure. This study focuses on new approaches to failure prediction by investigating the performance of Arima and Bayesian learning techniques. These approaches are applied to two types of failure datasets with different parameters and are shown to improve the accuracy of slope failure prediction.

In a real three-dimensional (3D) world, the ground around structures is also under 3D stress states. Although the 3D stress states or three principal stresses significantly affect the behavior of rock mass in field and laboratory tests, the intermediate principal stress is still ignored in the current analytical and numerical approaches for rock mechanics and rock engineering problems. To bridge this gap, in the current study, the effect of intermediate principal stress on rock mass strength was stressed and considered in a 3D revision of the well-known Hoek-Brown (HB) criterion, and then the proposed 3D criterion was further developed as a constitutive model for rock mass and applied to various rock engineering practices.First, a 3D revision of the HB criterion was proposed to consider the effect of the intermediate principal stress as well as the smoothness and convexity of the failure criterion in the 3D principal stress space. The smoothness and convexity of the proposed failure criterion were checked by mathematical proofs and comparisons among the proposed criterion and other 3D criteria were made regarding the true triaxial tests of elven rocks. Second, based on the laboratory tests on the stress-strain relations of rock, a unified constitutive model for rock mass was proposed using the proposed 3D strength criterion. And the proposed constitutive model was successfully implemented as a user-defined constitutive model in a commercial numerical modeling software FLAC3D. Then the performance of the proposed constitutive model was evaluated by applying it to both laboratory experiments and a tunnel project. Third, the proposed 3D criterion for rock mass was applied to theoretically analyze deep tunnels in rock mass with the consideration of disturbed zone, large strain and 3D strength. Validation of the theoretical solution was verified by a numerical simulation by FLAC3D, and parametric studies were conducted to investigate the influences of the disturbed zone