Sam Safavian is a Chartered Civil and Geotechnical Engineer with over 25 years of international experience in dam engineering, tailings storage facilities, mine waste management, geotechnical engineering, and risk assessment. His experience spans the UK, Australia, Asia-Pacific, Africa, the Middle East, and other international regions, covering numerical analysis, design, review, risk assessment, and governance of major tailings and water-retaining structures. In addition, he is a member of the British Dams Society Committee, represents the UK on the ICOLD Technical Committee on Tailings Dams as a co-opted member, and serves on the ISSMGE technical committees for embankment dams and slope stability. Sam is currently a Technical Director at SLR, where he leads and contributes to FMEA, QRA, dam break assessment review, embankment stability assessment, liquefaction assessment, internal erosion and piping assessment, and risk-informed decision-making for tailings storage facilities and water dams. Sam has authored several technical papers in areas including risk assessment, unsaturated and problematic soils, foundation engineering, landslides, embankment and tailings dams, and reinforced soils.
Enhancing Tailings Dam Sustainability through Risk-Based Safety Reviews – Case Study
Standard-based assessments have long formed the basis of dam safety evaluations by providing a structured framework to assess structural integrity, operational performance, and compliance with engineering standards. These approaches generally rely on deterministic analyses, prescribed loading conditions, and minimum factors of safety to demonstrate acceptable performance. While effective for verifying baseline compliance, they do not explicitly prioritise critical deficiencies, quantify uncertainty, or identify which mitigation measures most effectively reduce overall risk. As tailings storage facilities (TSFs) become increasingly complex and consequences of failure increase, reliance solely on prescriptive compliance may limit transparent and risk-informed decision-making.
This paper presents a Quantitative Risk Assessment (QRA) undertaken for a Tailings Storage Facility (TSF) and associated water basins to verify that societal and individual risks remain within ANCOLD tolerability criteria. The assessment considered multiple dam-breach scenarios and release directions, with particular focus on Scenario DB1 involving failure of the TSF North embankment and subsequent cascade failure of downstream water basins.
Annual probabilities of failure were estimated using conventional engineering assessments, site observations, reliability theory, engineering judgement, and a structured piping assessment addressing potential internal erosion mechanisms. Consequences were assessed through detailed dam-break modelling, and societal risks were quantified using F–N curves and expected annual loss of life.
The results demonstrate that a risk-based approach improves prioritisation of interventions and resource allocation by focusing on the dominant contributors to societal risk. The methodology supports defensible, evidence-based decision-making and targeted risk reduction, ultimately enhancing the long-term safety, resilience, and sustainability of tailings and water storage dams.
