Dam Failure Research Articles

ENVIRONMENTAL DISASTER IN BRUMADINHO: ASSESSMENT OF THE IMPACT ON THE REPUTATION OF VALE S.A.

The company Vale do Rio Doce was created in 1942 as a mixed capital corporation, being privatized in 1997. The company operates in 30 countries producing nickel, coal, copper, manganese, ferroalloys, iron ore and pellets. In 2019, a dam owned by the mining company, in the municipality of Brumadinho, failed and caused one of the biggest environmental disasters in Brazil, which could affect the company's reputation and its legitimacy before society to continue to exist. The general objective of this work is to analyze the impact of the dam failure on the company's reputation. The study is deductive, descriptive, comparative, quantitative, case study and documental, analyzing the company's reputation in five dimensions (media, academy, company, society and by the border of the last two). The findings showed a synergy between the dimensions, and in all of them there was a behavior that in the years before the disaster, the company had a reputation that guaranteed its legitimacy and, in 2019, this reputation was affected, but communication The mining company's organizational structure managed to recover its reputation and maintain the legitimacy to continue operating.

Institutional Impact on Corporate Discourse Decoupling and Institutional Void on Tailing Dam Failure

Institutional Impact on Corporate Discourse Decoupling and Institutional Void on Tailing Dam Failure

Critical Governance Lessons from a Mining Dam Failure Disaster in Brumadinho, Brazil

Critical Governance Lessons from a Mining Dam Failure Disaster in Brumadinho, Brazil

Institutional Voids Effects on Risk Management: Mining Companies Managing Tailing Dam Failures Risks

Institutional Voids Effects on Risk Management: Mining Companies Managing Tailing Dam Failures Risks

The Application of Remote Sensing Technology in Post-Disaster Emergency Investigations of Debris Flows: A Case Study of the Shuimo Catchment in the Bailong River, China

The Bailongjiang River Basin is a high-risk area for debris flow in China. On 17 August 2020, a debris flow occurred in the Shuimo catchment, Wen County, which blocked the Baishui River, forming a barrier lake and causing significant casualties and property damage. In this study, remote sensing, InSAR, field surveys, and unmanned aerial vehicle (UAV) techniques were used to analyze the causal characteristics, material source characteristics, dynamic processes, and disaster characteristics after the debris flow. The results showed that the Shuimo catchment belongs to low-frequency debris flows, with a recurrence cycle of more than 100 years and concealed features. High vegetation coverage (72%) and a long main channel (11.49 km) increase the rainfall-triggering conditions for debris flow occurrence, making it more hidden and less noticed. The Shuimo catchment has a large drainage area of 31.26 km2, 15 tributaries, significant elevation differences of 2017 m, and favorable hydraulic conditions for debris flow. The main sources of debris flow material supply are channel erosion and slope erosion, which account for 84.4% of the total material. The collapse of landslides blocking both sides of the main channel resulted in an amplification of the debris flow scale, leading to the blockage of the Baishui River. The scale of the accumulation fan is 28 × 104 m3, and the barrier lake area is 37.4 × 104 m2. The formation mechanism can be summarized as follows: rainfall triggering → shallow landslides → slope debris flow → channel erosion → landslide damming → dam failure and increased discharge → deposition and river blockage. The results of this study provide references for remote sensing emergency investigation and analysis of similar low-frequency and concealed debris flows, as well as a scientific basis for local disaster prevention and reduction.

Cascade failure risk analysis of mixed reservoirs based on disaster spreading theory

The reservoirs in the basin are connected in series or in parallel, forming a mixed reservoir group. Failure of a single dam in a mixed reservoir group may lead to subsequent failures of downstream dams, resulting in a cascading failure of the reservoir group. However, existing studies mainly focus on the impact of the upstream dam failure on the downstream dams, and lack a comprehensive consideration of the risk level of the upstream dams, the dam's own risk, and its own warning and flood release capacity. This limitation affects the accuracy of the actual risk calculation results of mixed reservoir dams. In this paper, the cascading failure risk chain is determined using graph theory, and a cascade failure risk analysis model based on disaster spreading theory is developed by combining dam break flood simulation and reservoir flood routing theory. The cascade failure risk is assessed in terms of the probability and the duration of a cascading failure. The model is applied to six mixed reservoirs in the Wujiang River Basin, China. The sensitivity of the model parameters is analyzed by examining a specific node, and the feasibility and effectiveness of the model are verified.

A Literature Review on Social Innovation and Community Flood Preparedness in Alignment with SFDRR and SDG: Recommendations for Dam Failure Flood Risk Management

A Literature Review on Social Innovation and Community Flood Preparedness in Alignment with SFDRR and SDG: Recommendations for Dam Failure Flood Risk Management

Emergency repairs downstream of earth and rockfill dams with water spring with indication of internal erosion

During periodic dam safety assessments, various anomalies are identified through field inspections, project documentation analysis, and structural behavior monitoring. These assessments aim to detect non-conformities, and engineering design firms propose technical solutions to address these issues. The primary goal of these reviews is to evaluate the overall state of conservation and structural safety, ensuring compliance with updated design criteria, revised standards, changing weather conditions, and technological advances. Dam renovations are crucial for enhancing operational capacity and preventive care. Implementing filtering materials within the dam's body establishes a drainage system to relieve internal pressures on the embankments and foundations. This prevents the washing away of soil particles due to internal erosion, known as "piping," a major cause of dam failures. Piping occurs when soil particles are displaced towards the outside of the embankment through the percolation process, particularly in the upstream area near the dam's base, where high hydraulic gradients and flows make it susceptible. This article presents a set of emergency or long-term solutions to address anomalies related to the onset of internal erosion in dams, with a focus on preventing piping. These solutions are vital for safeguarding the structural integrity and safety of these critical infrastructure components.

A global-scale applicable framework of landslide dam formation susceptibility

The formation and failure of landslide dams is an important and understudied, multi-hazard topic. A framework of landslide dam formation susceptibility evaluation was designed for large-scale studies to avoid the traditional dependence on landslide volume calculations based on empirical relationships, which requires comprehensive local inventories of landslides and landslide dams. The framework combines logistic regression landslide susceptibility models and global fluvial datasets and was tested in Italy and Japan based on landslide and landslide dam inventories collected globally. The final landslide dam formation susceptibility index identifies which river reach is most prone to landslide dam formation, based on the river width and the landslide susceptibility in the adjacent delineated slope drainage areas. The logistic regression models showed good performances with area under the receiver operating characteristics curve values of 0.89 in Italy and 0.74 in Japan. The index effectively identifies the probability of landslide dam formation for specific river reaches, as demonstrated by the higher index values for river reaches with past landslide dam records. The framework is designed to be applied globally or for other large-scale study regions, especially for less studied data-scarce regions. It also provides a preliminary evaluation result for smaller catchments and has the potential to be applied at a more detailed scale with local datasets.

Assessment of loss of life caused by dam failure based on fuzzy theory and hybrid random forest model

Assessment of loss of life caused by dam failure based on fuzzy theory and hybrid random forest model

РАЗРАБОТКА ФИЗИКО-МАТЕМАТИЧЕСКОЙ МОДЕЛИ РАЗРУШЕНИЯ ПЛОТИН СМЕШАННОГО ТИПА

When the body of dams of various types is destroyed, the problems of interaction of water flows with soil from local materials and with the concrete base of the dam, as well as the development of filtration processes in the body of the dam, become relevant. This model allows us to describe both the mechanism of failure of mixed-type dams and the erosion of soil in the coastal zone, for example, formed as a result of a breakthrough wave, which leads to catastrophic consequences. To obtain practical results, there is a need to simplify the processes being studied. The main problem in problems of soil erosion by turbulent water flow is an adequate description of sediment transport. Typically, for these purposes, semi-empirical formulas are used, obtained for various conditions (extremely rarely specified) and giving very different results. In this work, to describe the processes of soil erosion, the theory of the bottom layer is used, which makes it possible to derive a formula for sediment consumption theoretically. The proposed model combines approaches developed in well-known models of continuum theory and hydraulics.

A 2D numerical model for simulating landslide dam failure and induced morphological changes considering multi-layer and non-uniform sediments

ABSTRACT Landslide dams are formed by the blockage of rivers with landslides or any debris flows. Such dams are prone to failure and therefore, simulation of their failure and induced morphological changes is of great importance for hazard mitigation. Multi-layer and non-uniform sediments are usually observed in landslide dam materials, but these are rarely considered in simulations. In this paper, a two-dimensional numerical model considering multi-layered and non-uniform sediments is proposed. The model solves the shallow water equations, the Exner equation considering the different size fractions and Hirano's active layer equation based on a finite volume scheme in a weakly coupled approach. Two experimental tests are used to assess the applicability and accuracy of the model. The results show that it can well simulate the flow and morphological changes, as well as the surface coarsening and fining phenomena related to multi-layer and non-uniform sediments. The numerical results of dam failure process and morphological changes are in overall good agreement with the experiments, but the peak discharge and bed elevation tend to be underestimated when finer material is considered. Finally, the influence of sediments fractions and active layer depth on numerical results, as well as the limitations of the model are discussed.

Strength behaviour of stacked phosphogypsum incorporating dissolution–recrystallisation equilibrium

Large phosphogypsum (PG) stacks risk dam failure, with an insufficient consensus on the shear strength parameters for stability analysis. To this end, a combination of scanning electron microscopy (SEM) and triaxial tests was undertaken to investigate the underlying mechanism between crystal structure and shear strength of in situ and remoulded PG samples. The shear strength and deformation of PG were significantly affected by dissolution and recrystallisation. Dissolution weakened the cementation between particles, leading to a stabilisation of approximate 11 kPa under different confining pressures in the initial shear stage. The hardening phenomenon was related to the formation of cluster crystals under saturated conditions. An increase from 1.57 to 1.73 in the critical state stress ratio on remoulded samples occurred as the K0 consolidation time increased from 4 to 28 days. The compressive deformation of PG is accompanied by chemical consolidation, which is mainly impacted by the consolidation conditions (saturation) rather than the consolidation time. In the engineering design of the PG stacks, φ’ could be taken to a higher value at saturation and c’ could be higher when the dry density is higher than 1.2.

Dam break analysis of Ajwa dam during an extreme flood event in Vishwamitri basin

ABSTRACT Floods are one of the most common natural calamities and the disastrous action of flood becomes stringent when the floods are caused by dam failures. It is quite difficult to predict the failure of dam however the technique of dam break analysis provides an effective way to understand the flood wave generated due to assumed failure of dam. The present work focuses on dam break analysis of Ajwa dam constructed on river Surya, a tributary of river Vishwamitri. The work is divided into two parts. The first part consists of hydrological modeling of Vishwamitri basin using SWAT model and estimates the flood for 20-year return period and further calibrating and validating the model in SWATCUP 2019 using SUFI2 algorithm. The maximum flood calculated from SWAT model is taken as lateral inflow in dam break model setup. The breach parameters have been adopted as per the guidelines provided by Central Water Commission. Time of arrival of dam break flood at important locations downstream of Ajwa dam has been identified. The results reflect the potential of such a study to encompass the emergency action plans to safeguard the public and property in case of the possible flood event due to dam break.

Research on Failure Modes and Causes of 100-m-High Core Wall Rockfill Dams

Rockfill dams are the most competitive type of dam in complex geological environments. Identifying the failure modes and causes in high dams over 100 m is critical for better guiding high dam designs and implementing safety prevention and control measures. To this end, this paper investigated numerous cases of earth–rock dam breaches and failure modes in rockfill dams globally, with a particular focus on dams over 100 m in height, encompassing all such dams in China. The study categorized dam failure modes based on whether the dams were built before or after 1980. It also examined the causes of dam failures in terms of dam height, foundation characteristics and thickness, and failure time. Additionally, the paper analyzed a rockfill dam in China, with a height of 136 m and over ten years of operation, as a case study. We analyzed the spatial and temporal characteristics and causes of failures, such as dam crest cracking, high-level seepage, and gallery cracking, using the design situation, monitoring data, and numerical simulation. The paper also addressed issues related to dam design and foundation treatment, providing recommendations for improvement. The study indicated that the overall risk of total failure for dams over 100 m is already low. However, longitudinal cracks on the dam crest, core wall seepage, hydraulic splitting, and seepage damage to the dam foundation are primary issues in the current high core wall rockfill dams. These issues are mainly caused by uneven structural deformation of the dam and its foundation. A reasonable design of rockfill materials and foundations can mitigate these failures.

Analysis dam failure and flood inundation mapping: a case study of Manbaa-Al-Ghozlan dam, Biskra, Algeria

Floods in all their form are considered a real threat to many regions of the world. There are various types of floods, including those caused by the collapse of dams, which must be predicted to mitigate their effects. One of the non-structural solutions for flood mitigation and control is drawing the dam failure hazard map using effective and accurate flood models, which are essential for flood disaster prevention and mitigation. The study aims at the delineation of the flood plain area caused by Manbaa-Al-Ghozlan dam failure in the city of Biskra (About 40 km downstream the dam) and the surrounding communities (the village of El Outaya). Two scenarios were considered and simulated using the HEC-RAS 2D (River Analysis System) software, the first one is related to the sudden collapse of the dam and the second linked to under-evaluations of the projected flood of the dam spillway. The results of the first scenario confirmed that there are no risks threatening the city of Biskra taking into account the water depth which reached 5 meters in the city of El Outaya. Conversely, the water depth varying between 16m and 40m in the city of El Outaya and can exceed 16 meters in the city of Biskra for the second scenario, and this performs as a great danger for the zone. This simulation allowed designing the dam failure hazards map, which showed the areas threatened by flood waves, and consequently required a plan of security measures to moderate as much as possible the consequences of a dam collapse.

The elephant in the mine: Why voluntary sustainability standards are insufficient to ensure responsible mining

Environmental, social, and governance standards, along with mining sustainability and transparency initiatives, have taken centre stage in mainstream discussions about how society can source energy transition minerals responsibly. While we acknowledge the importance of private voluntary sustainability standards for improving mining performance and accountability, these must support and complement the crucial regulatory role played by the state and its enforcing agencies in resource-rich countries. From this perspective, we argue that the quality of public institutions remains ‘the elephant’ often overlooked in the room of global mining standards, and we call for re-centring the responsible mining debate around it.Tailings dam failures and uncertainties on the water impacts of brine-based lithium mining provide examples of why institutional strengthening in mineral-rich countries is crucial. The responsible mining agenda and its implementing instruments should shift from a focus on companies’ performances to one that is embedded in society with the aim of building trust in the sector and its governing authorities. For countries rich in transition minerals, this entails, among other things, reviewing organisational structures, strengthening authorities’ enforcement capacities, and allocating sufficient budget for regulators to deliver their oversight duties and avoid over-reliance on private standards.

Assessing the pressure variation in the plunge pool of Yusufeli dam

In dam engineering, plunge pools are critical terminal structures, often causing substantial scour that poses risks at the foot of the dam. Scouring near dams is a nationwide concern, as it has led to more dam failures than any other cause. Thus, evaluating hydrodynamic pressures from impinging jets is crucial for pool floor stability design. This study utilised physical models, experimental facilities and computational fluid dynamics models to assess hydrodynamic pressures at Yusufeli dam. Results indicate that Flow-3D analysis and empirical equations yield similar pressure readings on the bottom of the plunge pool, one-third of the free fall pressures of the physical model. The physical studies using Froude similitude revealed drastically lower Reynolds numbers compared to prototype flows, affecting turbulence and air entrance simulation. Consequently, model-scale resistance issues dominate physical model calculations, introducing uncertainty. This study underscores the importance of carefully assessing hydrodynamic pressures on plunge pool floors, as modelling approaches significantly impact results. Findings from this study can enhance plunge pool design and stability in dam engineering, promoting safer structures.

Simulation of landslide dam failure due to overtopping considering vertical soil particles distribution

Accurate prediction of potential landslide dam breaches is crucial for timely and effective emergency responses to the resulting flood. Although many models for landslide dam overtopping have been proposed in past studies, most of these models did not consider the heterogeneity of dam materials, which is important in reflecting the erodibility of soil. In this study, a new mathematical model for landslide dam breaches due to overtopping was proposed based on a constructed vertical distribution model of dam particle size. Two real-world dams, the Tangjiashan landslide dam and Baige landslide dam, were used to evaluate the performance of the proposed model. In addition, the proposed model was compared with four existing dam failure models, and sensitivity analysis was conducted on the median particle size and particle size distribution. The results demonstrate that the computational outcomes of the proposed model align more closely with the actual results, indicating that the proposed model outperforms the four existing models in accurately simulating the landslide dam failure process. It also suggests that ignoring the variation of dam material particle size along the vertical direction inside the dam body would increase the prediction relative errors of key breach outcomes.

Metal-contaminated sediment toxicity in a highly impacted Neotropical river: Insights from zebrafish embryo toxicity assays

The Fundão dam collapse was one of the largest mining-related disasters globally. It resulted in the release of mining tailings containing heavy metals, which contaminated the Doce River in southeastern Brazil. This study assessed the effects of acute exposure of Danio rerio embryos to sediments contaminated by mine tailings six years after the Fundão dam collapse. The study sites included P2, P3, and P4 in the upper Doce River, as well as site P1 on the Piranga River, an uncontaminated river. Sediment samples were analyzed for 10 metals/metalloid by atomic absorption spectrometry. In the assays, embryos were exposed to sediment from P1–P4 sites, and uncontaminated quartz was used as control sediment. Various biomarkers were applied to assess biological responses, and the integrated biomarker response (IBR) index was calculated for each site. Sediment samples revealed elevated levels of As, Cr, Cu, Hg, and Ni beyond Brazilian legislation limits. At 96-h exposure, embryo mortality rates exceeded 20% in P1, P2, and P3, higher than the control and P4 (p < 0.0001). Hatching rates ranged from 60 to 80% in P1, P2, and P3, lower than the control and P4 (p < 0.001). Larvae exposed to P2 sediment (closest to the Fundão dam) exhibited skeletal, physiological, and sensory malformations. Neurotoxicity was indicated by increased acetylcholinesterase activity and reduced spontaneous movements in embryos exposed to Doce River sediment. Contamination also increased metallothionein and heat shock protein 70 levels, along with changes in cell proliferation and apoptosis. Principal component analysis showed a good correlation between metals/metalloid in the sediment and larval morphometric endpoints. The IBR index highlighted suitable biomarkers for monitoring metal contamination in fish embryos. Overall, our findings suggest that sediment toxicity following the Fundão dam failure may compromise the sustainability of fish communities in the Doce River.