Towards Mine Closure: Assessing the Long-Term Stability of Open Pit Mine Slopes
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
ABSTRACT: The long-term stability of engineered slopes is becoming a critical focus point as the number of open pit mines anticipated to close in the coming years is increasing, and governments, regulators, and society are collectively placing more emphasis on sustainable management of mineral resources and land use (IISD, 2021). However, there are currently few guidelines on assessing long-term slope stability. Of central importance is the recognition that rock mass properties are not constants, and therefore, open pit slopes that are presently stable may not remain so in the future. Conventional engineering analyses generally assume the strength of a rock mass to be constant and, in doing so, fail to explain the temporal nature of rock slope behavior seen in monitoring data. Data shows that pit slope movements are intermittent, correlating with benching and seasonal precipitation patterns. These initiate episodic damaging events that, in the closure context, control strength degradation and impact long-term slope performance through progressive failure (Eberhardt et al. 2004). This talk will summarize the author's research over the last 20 years into progressive failure, its advancement of our mechanistic understanding of deep-seated rock slope failure, and recent results and guidance in applying it to open pit slope stability assessments and mitigation efforts to aid mine closure designs. Empirical data will be presented to show the evidence for progressive failure, with a focus placed on transient pore pressures driven by seasonal precipitation. Upon closure, changes to the slope geometry (i.e., benching) cease, but seasonal precipitation continues. Progressive failure posits that transient pore pressures in response to infiltration or groundwater recharge act to locally decrease effective stresses, promoting slip along non-persistent discontinuities, which in turn may cause the slip of adjacent fractures and/or the failure of intact rock bridges. Such repeated fluctuations in pore pressures and effective stresses thus are a key driver of progressive failure and can be equated to fatigue, where the rock slope experiences a slow weakening through repeated load cycles. Results from mine closure analyses will be presented, demonstrating how slope displacement monitoring and modeled groundwater fluctuations can be used to calibrate numerical models and establish the degree of criticality present in a slope. The modeling of seasonal variations further enables reference to be made to time in calculations that are otherwise limited to stress-strain behavior. This provides a means to assess displacement rate thresholds at which behavior change may occur for a given failure mode, which can be used to establish and constrain early warning alarm thresholds and trigger action response plans (TARPs). Examples will also be provided incorporating allowances for the development of a pit lake post-closure and for long-term stability improvement through engineered buttress designs.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it