Announcement distributed 12 days in advance due to GSSO absence. 

School of Civil and Environmental Engineering

Ph.D. Thesis Defense Announcement

Assessment of Large Deformation Problems in Tailings Engineering Using Particle-Based Methods

By Renzo S. Cornejo Tejada

Advisor:

Dr. Jorge Macedo Escudero (CEE)

Committee Members: Dr. Susan Burns (CEE), Dr. Paul Mayne (CEE), Dr. Alba Yerro Colom (CEE - VT), Dr. Scott Olson (CEE - UIUC)

Date and Time: November 25th, 2025, at 9:00 am EST

Location: Mason 2119/ Teams (ID: 248 089 285 775 59, Passcode: MZ2hX76L)

ABSTRACT
Recent tailings storage facility (TSF) failures - including Fundão, Cadia, and Feijão - have exposed gaps in the geotechnical community’s understanding of mine tailings behavior. This thesis reassesses the triggering mechanism and post-triggering runout of two major TSF failures (Cadia and Fundão) by coupling small-deformation stability analyses with large-deformation simulations. These studies demonstrate the value to link failure initiation to runout and to quantify sensitivities relevant to design, forensic evaluation, and risk-informed mitigation of TSFs. Additionally, this thesis evaluates field and numerical investigations from multiple tailings storage facilities to advance interpretation of tailings based on CPTu data under partially drained conditions. Integrating CPTu, laboratory characterization, and rate-dependent numerical modelling reduces ambiguity in identifying operative drainage conditions and constraining parameters such as the state and coefficient of consolidation. These findings highlight the need to account explicitly for partial drainage and stratification when using CPTu to characterize tailings and to adopt coupled test–simulation workflows for more reliable site assessment.