M.Sc. Civil Eng. Thesis Presentation & Defense

Master's Candidate: Yan Wang
Supervisor: Dr. Liang Cui
External Examiner: Dr. Haiqiang Jiang (Northeastern University - China)
Internal Examiner(s): Dr. Wa Gao, Dr. Ahmed Elshaer, and Dr. Sam Salem (Director, Civil Eng. Graduate Programs - Chair)

Thesis Title: Analytical Modeling of Rock/Cemented Tailings Backfill Interface Interaction and Its Engineering Application

Date and time: Friday, January 22nd, 2021, between 10:00 A.M. and 12:00 P.M.

Zoom meeting:

Dr. Sam Salem is inviting you to a scheduled Zoom meeting.

Topic: Master's Thesis Defense and Presentation by Yan Wang
Time: Jan 22, 2021 10:00 AM Eastern Time (US and Canada)

Join Zoom Meeting
https://lakeheadu.zoom.us/j/93883445332?pwd=MGF0RmxnMDVZSE1FeisxWURIQzdM...

Meeting ID: 938 8344 5332
Passcode: 126934

Abstract:
Cemented tailings backfill (CTB) technology has gradually become a standard practice in underground mines around the world over the last three decades. This is because CTB can stabilize underground mine structure, maximize ore recovery, and mitigate the potential environmental hazards such as acid and metalliferous drainage (AMD). However, after placement into underground excavation, the consolidation of CTB occurs due to the water drainage. The resultant consolidation cannot only change the saturation condition of CTB materials, but also cause the relative displacement between CTB and rock mass. The latter will activate the passive rock/CTB interface resistance and directly affects the magnitude of internal stress (i.e., arching occurs in CTB). Therefore, it is necessary to quantitatively evaluate the effect of rock/CTB interface interaction on the internal stress of CTB for its optimal design. To characterize the internal stress in CTB, a new 3D effective stress model is developed in this study. The developed model integrates Bishop's effective stress principle, water retention relationship, and arching effect. All model parameters are determined from measurable experimental data. The uncertainties of the model parameters are examined by sensitivity analysis. A series of model applications is conducted to investigate the effects of field conditions on the internal stress in CTB. The obtained results show the proposed model is able to capture the influence of operation time, stope geometry, and rock/CTB interface properties on the effective stress in CTB. Hence, the developed model can be used as a useful tool for the optimal design of CTB structure.