Advancing Tailings Dam Performance Monitoring with Distributed Acoustic Sensing

Ouellet, Susanne

Advancing Tailings Dam Performance Monitoring with Distributed Acoustic Sensing

dc.contributor.advisor	Dettmer, Jan
dc.contributor.author	Ouellet, Susanne
dc.contributor.committeemember	Hutchinson, Jean
dc.contributor.committeemember	Lato, Matthew
dc.contributor.committeemember	Pidlisecky, Adam
dc.date	2024-09
dc.date.accessioned	2024-09-04T16:47:25Z
dc.date.available	2024-09-04T16:47:25Z
dc.date.issued	2024-08-30
dc.description.abstract	Tailings dams require careful design, planning and monitoring throughout their life cycle to prevent a potential failure. Such failures can occur due to a variety of causes, such as overtopping, structural and foundation conditions, static or seismic liquefaction, and erosional processes. As such, a tailings dam monitoring system should be capable of identifying potential behaviours leading up to different failure modes and with adequate warning time. This thesis investigates an emerging fiber optic sensing technology, distributed acoustic sensing (DAS), with a passive geophysical technique (coda wave interferometry; CWI), to advance monitoring of tailings dam performance. The first study provides a proof-of-concept of CWI using geophones at an active tailings dam, from June to July 2020. Following this study, a fiber optic cable located near the geophones was then employed with DAS and CWI from April to August 2021. CWI was used to infer changes in shear wave velocities up to ~1.9% over depths ranging from ~6 to ~16 m. An inverse correlation between the dv/v and tailings pond levels in the summer months aligned with the earlier geophone study. This study demonstrated how DAS can augment traditional geotechnical monitoring by providing higher spatial resolution of dv/v as a proxy for dam performance. While higher frequency (> 1Hz) DAS measurements can be used with CWI, lower frequency (<1 Hz) DAS measurements can provide complementary information on changes in strain near the cable. A three-day low-frequency DAS dataset encompassing a rainfall event was acquired from the Hollin Hill slow-moving landslide observatory. A conceptual framework was developed to interpret the onset of movement, retrogression, and a flow lobe surge with nanostrain-rate sensitivity, providing new insights into the kinematics of a slow-moving landslide. Collocated slope inclinometer data correlated with the inferred DAS displacements. This study demonstrates how lower frequency DAS can also provide valuable information for tailings dam monitoring applications, using slope inclinometer data (commonly installed for tailings dam monitoring) to evaluate DAS performance. Together, these findings demonstrate how DAS can be used to advance monitoring of tailings dam performance to reduce the risk of future dam failures.
dc.identifier.citation	Ouellet, S. (2024). Advancing tailings dam performance monitoring with distributed acoustic sensing (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/119602
dc.language.iso	en
dc.publisher.faculty	Science
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	distributed acoustic sensing
dc.subject	tailings dams
dc.subject	geotechnical engineering
dc.subject	coda wave interferometry
dc.subject	passive seismic interferometry
dc.subject	distributed fiber optic sensing
dc.subject	environmental seismology
dc.subject.classification	Geophysics
dc.subject.classification	Engineering--Mining
dc.subject.classification	Engineering--Civil
dc.title	Advancing Tailings Dam Performance Monitoring with Distributed Acoustic Sensing
dc.type	doctoral thesis
thesis.degree.discipline	Geoscience
thesis.degree.grantor	University of Calgary
thesis.degree.name	Doctor of Philosophy (PhD)
ucalgary.thesis.accesssetbystudent	I do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.