Development of a Safety Case for a closed TSF in the tropics.
Tailings storage facility (TSF) owners should meet their legal duties and conform with current industry practice in relation to tailings dam safety. In the common law frameworks, this involves demonstrating that the TSF risks are eliminated whenever reasonably practicable, and if not, these risks are reduced so far as is reasonably practicable... Read more
When the bottom-line impacts dam safety: Case studies of commercial realities leading to increased risks.
All projects are constrained by a number of variables. This is classically represented by the Project Management Triangle of Scope, Time and Cost, though there are other more modern versions with different variables. Regardless, these constraints are real and must be managed effectively in order to achieve successful project outcomes... Read more
Development of a preliminary risk assessment tool for a portfolio of TSFs with limited and uncollated data.
As risk assessment methods have developed and become more understood, organisations involved with operating and maintaining tailings storage facilities (TSFs) have become more open to managing their TSFs based on a risk profiles of their portfolio rather than fallback methods... Read more
Tailings Storage Failures: Impact on the industry, design, operation and people.
As predicted by Powel (2000) claims for professional negligence are very common and their frequency is increasing due to the increasing demand for professionals’ services, specialisation, higher standards, intolerance of poor performance by societies and the increasing litigious nature of business... Read more
A consequence-based tailings dam safety framework.
Despite the development of tailings dam safety standards, guidelines, bulletins, risk assessment tools and management tools, tailings dam failures with high consequence have occurred at a similar rate over the last ten years as they did before. At the time of writing this paper (January 2019) another tailings dam failed in Brazil resulting in a large number of fatalities... Read more
Factor of Safety - do we use it correctly?
The principle of minimum acceptable factors of safety has been used to assess the stability of embankment dams for decades. The commonly applied minimum acceptable factors of safety remain very similar to those recommended in the early 1970's, despite the development of new design tools and better understanding of material behaviour... Read more
Design of dams for mining industry.
National and international guidelines use a consequence category framework for selection of design parameters, loading conditions and surveillance requirements. Tailings dams are frequently assigned high dam break consequence categories due to the potential for loss of life, significant impact on environment and damage assets and infrastructure... Read more
Probabilistic slope failure risk estimation of dam with zones of weak foundation material.
For existing dams built before modern theories and understanding of soil mechanics were fully developed, it was often the case that comprehensive investigations into the properties of the embankment and foundation material were not carried out. With more stringent dam safety requirements and engineering criteria, and a better understanding... Read more
Anomalies in design for mining dams.
The design of dams for mining projects requires processes and technology that are unfamiliar to many mine owners and managers. Dam designers rely on ANCOLD assessments of Consequence Category, commonly leading to a High rating for mining dams due to a combination of potential loss of life, impact on environment and... Read more
Abracadabra – the disappearing tailings dam.
The independent expert review panel for the Mount Polley Tailings Storage Facility failure came out strongly recommending changes to the technology of tailings dams in British Columbia (and by inference, world-wide). The Panel had examined the historical risk profile of tailings dams in British Columbia and recommended, amongst other things, that best ... Read more
Gordes Dam – A Turkish Delight.
Gördes Dam is a nickel and cobalt mine tailings dam situated in a seismically active zone in Manisa Province, Western Turkey. The dam is a conventional cross valley earthfill structure with a fully lined storage basin. The starter embankment with a maximum height of 50 m will be raised in downstream lifts to an ultimate height of 90 m... Read more
Investigations into lateritic soils at Millstream Dam.
Millstream Dam is located in the South West Region of Western Australia and is founded on lateritic soils, which are a common surface material throughout the region. These lateritic soils have been formed by weathering of basic or acidic parental rocks, in a tropical or semitropical climate. As a consequence of intensive long term leaching, some of the lateritic ... Read more
Challenges of dam design on lateritic soils.
The Western Australia Water Corporation plans to increase the storage capacity of Millstream Dam, which is located near Bridgetown in the south west region of WA. The existing dam is an 18 m high zoned earthfill embankment constructed in 1962. The dam suffered a block heave of the foundation at the downstream toe during the first filling, probably attributable... Read more
Investigations and remedial works at Drakesbrook Dam in Western Australia.
Drakesbrook Dam is a 17m high earthfill embankment constructed in 1931 to provide water for the Waroona Irrigation District, 80km south of Perth. The dam has a storage capacity of 2.30 GL and is classified as a “High A” hazard dam according to ANCOLD Guidelines on Dam Safety Management. A Dam Safety Review, undertaken in 2001 identified a number of ... Read more
Analysis of soil water response to grass transpiration.
This paper focuses on numerical modelling of soil water movement in response to the root water uptake that is driven by transpiration. The flow of water in a lysimeter, installed at a grass covered hillslope site in a small headwater catchment, is analysed by means of numerical simulation... Read more
Jiri Herza presenting at the ICOLD 2019 Conference in Ottawa, Canada