Dam Failure Research Articles

Influence of approach shape of debris flow on impact load to open Sabo dam in experiment

Recently, the magnitude of landslide caused by torrential rain and typhoons is increasing in Japan. This high intensity rainfall disaster induces some structural failure of steel pipe open Sabo dams. Thus, current static design loads and impact loads are being considered. To prevent some structural failure of the dam, a new design concept is necessary at the severe load that is exceeding the present design load. However, the influence of debris flow impact load on steel pipe open Sabo dam is not clear to make a design load. The study experimentally approaches a vertical load distribution shape and its time history based on a comparison with a wedge approach shape and a front boulder concentrated shape. The load and moment action of a front boulder concentrated shape debris flow is greater than that of a wedge approach shape. Mechanism making the difference is made clear by observation of vertical detail measurement of impact load.

Assessment of the influence of DTM quality on dam rupture simulation processes

Computer programs applied to disaster simulation are widely used and widespread today, taking as input various data types, from specific to the application area to DTMs (Digital Terrain Models). This need for data input and, in particular, data related to relief is very relevant in prediction procedures for forecasting catastrophes, such as the failure of tailings mining deposit dams. Therefore, it is of fundamental importance to know and quantify the quality of this input data in question, in order to effectively serve this application. To this end, in this research, several tests were carried out, using as a reference for best results those obtained with the introduction of DTM from a LIDAR (Light Detection and Ranging) flight survey, this data being used as one of the primary and input into HEC-RAS (Hydrologic Engineering Center-River Analysis System). Subsequently, these same data had their spatial resolution degraded, that is, the pixel size increased, generating models with worse quality for new inputs and obtaining new simulation results of mining dam failures. The test area of the B1 Dam, located in Brumadinho-MG, Brazil, was used as a laboratory, where one of the biggest mining disasters in the world recently occurred and, for which, there are real data from the area affected by the dam collapse. The results obtained demonstrated that the use of an DTM with a spatial resolution of at least 2.5 meters or better, with DTM class A cartographic quality compatible with the most recent Brazilian standard, would guarantee reliable results.

Glacier dam evolution and knickpoint migration in the Yarlung Tsangpo Gorge, eastern Himalayas, since the last glacial period

The repeated cut-and-fill process induced by the late Quaternary glacial damming and catastrophic outburst events in the Yarlung Tsangpo Gorge (YTG) in the eastern Himalaya may reflect the interaction between rock uplift, climate change and river incision in the southeastern Tibetan Plateau. Here we provide the detailed reconstruction of the cut-and-fill history recorded at the entrance of the YTG, based on geomorphological, sedimentological and chronological analyses. The results reveal a catastrophic glacial-dam breach during the last deglaciation (∼18 ka), and the outburst flood eroded a ∼30–45 km long valley floor filled with glacial diamicton and glaciofluvial deposits, which was later further incised to form terrace T2 with a height of ∼350 m. The second dam failure occurred at ∼5 ka, producing a spillway, forming terrace T1 with a height of ∼100 m. The vertical incision and horizontal migration rate of the knickpoint at the glacier dams were estimated as 0.02 m/yr, and 2.5 m/yr since the last deglaciation, based on the age of the terraces and distance of the knickpoints. We consider the glacial dams to be effective in impeding headward river erosion during glacial periods. This, along with rapid river headward erosion during the last interglacial period, results in two knickpoints on the longitudinal profile due to the differences in erosion resistance. The fluvial reaches corresponding to the repeated cut-and-fill processes are confined to the center of the Namche Barwa massif, suggesting that rapid rock uplift counteracted fluvial headward erosion and maintained the stability of the bedrock knickpoint. Therefore, in comparison to glacial dams, tectonic uplift is the most important component in plateau margin stabilization.

Experimental study on the failure mechanisms of non-cohesive soil landslide dams with different scales

The blocking of rivers by landslides is common in mountainous areas with deep and narrow valleys. Landslide dams may pose a severe threat to the safety of life and property downstream in the event of a sudden dam failure. The similarities and differences in failure characteristics between the large-scale and small-scale landslide dams are insufficiently understood. Relatively large-scale physical models to study the failure processes are expensive and time-consuming. Relatively small-scale experiments give a better opportunity to explore the failure mechanisms, but the scale effect needs to be considered. In this study, a large-scale test and three small-scale flume tests were conducted to study the failure characteristics of landslide dams with a scale ratio of 10:1. Experimental results showed that the large-scale and small-scale dam tests followed almost the same failure processes, which can be divided into three stages: seepage on the downstream surface, slope failure, and overtopping and erosion. But they differed in some quantitative outcomes such as the failure duration and pore water pressure value. The small-scale dam tests can be used to study the failure processes and mechanisms of landslide dams, but can not be used to predict the specific parameters due to the scale effect.

Flood Routing and Dam Breach Parameter Calculation on Sepaku Semoi Dam

Flood Routing and Dam Breach Parameter Calculation on Sepaku Semoi Dam

Evaluating the role of soil properties on volumetric shrinkage characteristics of marine and inland clays

ABSTRACT Clayey soils that exhibit swelling and shrinkage behaviour have paved the way for various engineering problems such as foundation failure, slope stability issues, failure of earthen dams, cracking of clay liners, etc. The shrinkage behaviour of soil is often quantified by employing various direct and indirect experimental techniques to establish the Soil Shrinkage Curve (SSC), a relationship between soil volume change and moisture content. However, SSC can reveal only the overall volume change and does not exclusively comprehend the variation of volumetric shrinkage in linear and radial directions. Hence, a series of desiccation tests were performed on marine and inland clayey soils of different consistencies to evaluate the contribution of volumetric shrinkage in these orientations. From this study, it has been observed that the linear component of volumetric shrinkage was higher for soil samples with a consistency state between 1.0 and 1.5 times the liquid limit. However, the radial component of volumetric shrinkage was found to be higher at the end of the desiccation test for soils with an initial moisture content at or below the liquid limit. Furthermore, the results obtained from the present study have been utilised to establish the influence of soil properties on radial, linear, and total volumetric shrinkage.

Limiting physical properties of Technosols formed by the Fundão dam failure, Minas Gerais, Brazil

ABSTRACT Physical properties of the Technosols formed by the tailings deposition may constitute a physical barrier that limits water movement and plant development due to the properties received from those sediments. This study aimed to evaluate the physical quality of the Technosols formed by the deposition of sediments displaced by the Fundão Dam failure, Mariana, Minas Gerais State, Brazil, based on the evaluation of physical properties and Load Bearing Capacity Models (LBCM). For that, three areas under different vegetation types were selected: eucalyptus (Euc), forest with human-assisted revegetation (RF), and forest with native vegetation (NF). Three sampling subareas were demarcated in each area: non-impacted areas (Ni), and Technosols formed in directly impacted areas (Di), and partially impacted areas (Pi). Undisturbed samples were collected in two layers and subjected to the uniaxial compression test after equilibration at five matric potentials. Soil compression curves and LBCM were determined. Soil bulk density (BD), total porosity (TP), organic matter (OM), granulometry, and particle density (PD) were also determined. Clay content was less significant, and the silt and very fine sand content was significantly higher in the Technosols, generating an increase in BD and reduction in TP. Technosols generally exhibited greater load-bearing capacity due to higher pre-consolidation pressure values attained by these soils due to the lower clay and OM contents. High resistance of these soils is one limitation for revegetation of the areas evaluated, being necessary management practices to improve physical properties of the Technosols.

Tailings dams’ classification based on risk using data from SIGBM

The Brumadinho and Mariana tailings dam failures in Brazil tragically highlighted the critical need for robust risk management in the mining sector. Tailings dams, by their very nature, pose significant risks to downstream communities and the environment in the event of failure. To mitigate these risks, a comprehensive risk classification system is essential. This abstract emphasizes the real-world impact of dam failures and strengthens the importance of risk classification. Risk analysis plays a central role in identifying, quantifying, and ultimately mitigating the potential consequences of tailings dam failure. The classification process considers various factors that influence dam stability and safety, including dam geometry and construction methods — the design and construction techniques employed significantly impact a dam's stability; tailings characteristics — the physical and chemical properties of the stored tailings can influence factors like liquefaction potential; operating conditions — factors like the rate of tailings deposition and the presence of seismic activity need evaluation; drainage system effectiveness — a well-functioning drainage system is crucial for managing pore pressures within the dam. By analyzing these elements, risk classification aims to categorize tailings dams into distinct risk levels, typically ranging from low to very high. This categorization allows for targeted risk mitigation strategies to be implemented based on the specific vulnerabilities of each dam. This paper proposes a methodology for risk classification of tailings dams utilizing data from the Brazilian National Mining Agency's (ANM) Integrated Mining Dam Management System (SIGBM). The study focuses on 203 dams situated in Minas Gerais, a Brazilian state with a history of dam failures. Data was extracted from SIGBM in February 2023. This research not only presents a general risk classification for the assessed dams but also delves deeper, offering a quantitative measure of vulnerability, risk potential, and potential consequences of a failure event for each individual dam.

Numerical simulation and experimental study of fluid–structure interactions in elastic structures based on the SPH method

The study of fluid–structure interactions in elastic structures is highly important in hydraulic structural engineering. This paper adopts the smooth particle hydrodynamics (SPH) coupling method to simulate dam failure water impact elastic plate flow and solid coupling problems. In addition, a numerical simulation is performed on the study of the free surface flow impact of the elastic plate structure on the main dynamic characteristics, including the impact force distribution and the change process. Additionally, the elastic structure of the vibration amplitude and frequency change rule, as well as the drastic changes in free surface flow, are also carried out. In this paper, the synchronous finite element algorithm is used to analyze the problem to obtain FEM results Additionally, two-dimensional benchmark physical tests are designed for dam-break water flow impacting an elastic plate are conducted, focusing on a comparative analysis of the numerical results of the SPH method with the results of physical tests and verifying the validity, accuracy, and superiority of the SPH coupling method for solving the problem of fluid‒solid coupling in elastic structures. On this basis, to explore the relevant physical quantities that cannot be measured or described during the test process, the flow–solid coupling characteristics of the elastic plate impacted by water flow are further understood by analyzing the nature of the flow field, the change in the flow–solid force of the elastic plate and the change rule of the frequency spectrum. The results show the following: (i) The jumps in velocity between the streams and the strong curvature of the free liquid surface lead to the creation of vortices at the cavities. (ii) The flow solid force under the impact of water flow increases and then decreases, and the smaller the deformation of the elastic structure is, the greater the force is. (iii) The vibration frequency of the fixed end of the elastic structure gradually decreases along the free end frequency, and the larger the deformation of the free end of the elastic plate is, the weaker its vibration response is. In addition, the natural frequency of the elastic plate under water flow impact is slightly lower than that under free vibration of the elastic plate. The related research results provide reference and guidance for the fluid–structure interaction problem.

Towards a Circular Economy in the Mining Industry: Possible Solutions for Water Recovery through Advanced Mineral Tailings Dewatering

The mining industry is confronted with substantial challenges in achieving environmental sustainability, particularly regarding water usage, waste management, and dam safety. The increasing global demand for minerals has led to increased mining activities, resulting in significant environmental consequences. By 2025, an estimated 19 billion tons of solid tailings are projected to accumulate worldwide, exacerbating concerns over their management. Tailings storage facilities represent the largest water sinks within mining operations. The mismanagement of water content in tailings can compromise their stability, leading to potential dam failures and environmental catastrophes. In response to these pressing challenges, the mining industry is increasingly turning to innovative solutions such as tailings dewatering and water reuse/recycling strategies to promote sustainable development. This review paper aims to (I) redefine the role of mine tailings and explore their physical, chemical, and mineralogical characteristics; (II) discuss environmental concerns associated with conventional disposal methods; (III) explore recent advancements in dewatering techniques, assessing their potential for water recovery, technical and economic constraints, and sustainability considerations; (IV) and present challenges encountered in water treatment and recycling within the mining industry, highlighting areas for future research and potential obstacles in maximizing the value of mine tailings while minimizing their environmental impact.

Case studies of assessment of human health risks after the dam failures of the Córrego do Feijão Mine and Fundão in Brazil

ABSTRACT In recent years, there has been an increase in environmental catastrophes involving mining dam failures. This study assessed the potential risks of iron ore tailings in riparian soils to human health after the worst dam collapses recorded in Brazil: from Córrego do Feijão Mine-CFM and Fundão. Chemical monitoring data from the three-year time interval since the collapses were used to estimate human risk indexes for trace elements such as arsenic, cadmium, chromium, mercury, nickel, lead, and zinc. In both case studies, the adult group indicated a propensity for the development of non-carcinogenic diseases through ingestion, inhalation and dermal pathways for all contaminated areas. Overall, children showed an exacerbated sensitivity to possible cancerous and non-cancerous effects, especially in the areas surrounding the dams and in Barra Longa, São José do Goiabal, Córrego Novo, Veneza, Periquito, Governador Valadares, Tumiritinga, Conselheiro Pena, Honório Fraga and Linhares (from the Fundão dam) and in all study areas from the CFM dam. These assessments demonstrate that in regions with mining activities, the cumulative effects of trace elements over time are harmful and expected. Therefore, there is a need for greater supervision by competent government bodies of conservation practices that enable environmental recovery or mitigation of their impacts, ensuring appropriate health and well-being conditions for local residents and workers.

Flow Failure Assessment for Dams and Embankments

A procedure is proposed to assess whether a liquefied strength should be applied to a zone of non-plastic silt, silty sand, and/or clean sand in a static or seismic stability analysis to assess the flow failure potential of dams and slopes. The procedure consists of the following five main steps to assess flow failure potential: (1) assess static liquefaction potential of segments along a potential failure surface, (2) assess seismic liquefaction potential by calculating the factor of safety against liquefaction (FoSLiquefaction) for any amplitude of shaking in each segment; (3) if liquefaction is not triggered in any of these segments, assess the magnitude of shear-induced pore-water pressures due to seismic or vibratory events of any amplitude; (4) assign a liquefied strength to segment(s) that experience seismic liquefaction, i.e., FoSLiquefaction < 1 or significant pore-water pressure generation, i.e., total pore-water pressure ratio ≥ 0.7; and (5) conduct a post-triggering stability analysis to assess flow failure potential. This procedure is illustrated using the 1971 seismic permanent deformations of Upper San Fernando Dam and 2015 Fundão tailings dam failure.

Novel approach to the derivation of dam breach parameters in 2D hydrodynamic modeling of earthquake induced dam failures

Current methods of dam breach analyses adopt a deterministic approach. Applying these methods to Concrete Faced Rockfill Dams (CFRD) is fraught with huge levels of uncertainty, especially in the context of natural hazards. The frequency and magnitude of rainfall and earthquakes are higher in today's world. In the literature, the complete collapse of dams is modelled on dam breach parameters that define the dam break outflow but are not related to the return periods of natural hazards. As more new dams are constructed to control the floods in intra-plate seismic regions, this study presents a novel approach to the derivation of generalized dam break parameters for CFRD based on the structural analysis of Finite Element Model (FEM) simulations for peak ground accelerations corresponding to 475 and 2475 year return periods. Furthermore, the occurrence of rainfall and earthquake for different return periods are modelled using 2D hydrodynamic simulations. Results show the significance of generalized dam breach parameters for planning and managing CFRDs during earthquakes. The study emphasizes the utilization of structural analysis outputs for the hydraulic modeling of dam breaks, which will result in more specific and accurate dam break parameters. Additionally, the study has shown that the flood risk and the severity will increase with the intensity of earthquake and rainfall magnitudes. Disaster mitigation strategies can be optimized by considering the integrated occurrence of rainfall and earthquakes based on the probability of occurrence, demonstrated using a case-study dam. Another significant outcome of the study is the effect of soil saturation condition during a dam break, which reveals that areas within 40 km of the dam breach location might be worst affected.

Electroosmosis of gold tailings under multiple electrokinetic geosynthetics electrodes

In dry-stack tailing ponds with high fine-grained content, a high long-term saturation line can lead to dam failure. Electroosmotic consolidation is an effective method for reducing dam saturation lines. However, traditional electrodes have low corrosion resistance and poor contact, which limits the development of electroosmotic drainage technology for tailings. In this study, an electroosmotic drainage device, an electrokinetic geosynthetic (EKG) electrode, was designed. The influence law of the electrode material, potential gradient, and number of electrodes on the water drainage, current, and resistance was analyzed. The results show that the EKG electrode has excellent corrosion resistance, with its weight loss after electroosmosis, water drainage, and equivalent allowable current being 1.67%, 122%, and ∼2.3 times that of a copper electrode, respectively. Furthermore, it was found that the optimal potential gradient was 1.2 V/cm, and the water drainage cannot be improved by an exceedingly high potential gradient. The current pathway in the test box was in parallel, and the water drainage increased to 410% and the contact resistance decreased by 83% when the number of electrodes was four. These results and novel methodology provide new ideas for EKG electrode design and represent an effective method for saturation line control in gold tailing ponds.

The Impacts of River Channel Blockages Caused by Sliding Embankment Collapses during Earthquakes

New Japanese regulations governing earth embankment construction were introduced after a debris flow in Atami City, Shizuoka Prefecture, caused significant damage. Slope failures block river channels during earthquakes, triggering flooding, inundation, and debris flows. Appropriate risk assessments are crucial for residential areas potentially impacted by earthen embankment landslides during seismic events. This study evaluates the methods used to assess the potential damage caused by such landslides and previous research on the harm caused by embankment failures during earthquakes. We derived predictive equations based on statistical analyses of historical dam landslides that triggered river channel blockages when residential earth embankments failed in the Nigawa Yurino area. The equations describe the morphologies of landslide dams in river channels. The results indicated that the predictive equations were reasonably accurate. We built and validated a two-dimensional model of landslide dam overtopping and breaching using experimental data on a gently sloping dam. We derived the outflow volumes associated with residential earth embankment failures when full reservoirs breached in the Nigawa Yurino area. Our findings suggest that the peak outflow volumes after such embankments breach are generally lower than those associated with dam landslides or deep-seated dam failures, but higher than those of glacial lake outburst floods.

Analysis of seepage failure probability for high core rockfill dams during rapid drawdown of reservoir water level

Rapid drawdown (RDD) is an abnormal reservoir flood control operation that may cause seepage failure of high core rockfill dams. In this paper, a novel framework combining Bayesian inference and transient unsaturated seepage simulation is proposed to evaluate the seepage failure probability of the core during RDD. The dynamic hydraulic boundaries utilized in the simulation are first determined by the performance of water release structures. The extreme learning machine (ELM) is then employed as the surrogate model to establish the mapping relationship between material parameters with simulated seepage pressure and hydraulic gradient. The Bayesian inference method is applied to characterize the uncertainty of material parameters based on seepage monitoring data. Finally, the posterior distribution samples of random parameters are utilized to calculate the seepage failure probability of the core. The seepage safety of the core under different drawdown rates is studied with a real 186 m high core rockfill dam. The results reveal that a faster RDD rate can lead to an increased probability of seepage failure. The maximum failure probability is 35.56 % for the four release structures working together (about 0.316 m/h), higher than 23.16 % for the three release structures (about 0.165 m/h). It is also found that the peak of seepage failure probability often occurs in the middle stage of RDD. Therefore, to ensure the safety of the project, it is important to control the RDD rate and carefully monitor the seepage pressure. From the point of view of seepage failure, the proposed method for evaluating the safety of core rockfill dams under RDD is of high guiding significance to the risk assessment of similar projects under extreme conditions.

Integrating reverse osmosis to a conventional river water treatment plant as a strategy to produce drinking water after mining dam rupture events: a case study

ABSTRACT Incidents of mining dam failure have compromised the water quality, threatening the water supply. Different strategies are sought to restore the impacted area and to guarantee the water supply. One example is water treatment plants that treat high-polluted waters within the required limits for their multiple usages. The current study assesses the integration of reverse osmosis (RO) to a river water treatment plant (RWTP) installed in Brumadinho (Minas Gerais, Brazil) to treat the water from the Ferro-Carvão stream impacted by the B1 dam rupture in 2019. The RWTP started eleven months after the mining dam rupture and is equipped with eight coagulation-flocculation tanks followed by eight pressurised filters. A pilot RO plant was installed to polish the water treated by the RWTP. Water samples were collected at different points of the water treatment plant and were characterised by their physical, chemical, and biological parameters (160 in total). The results were compared with the historical data (1997–2022) to reveal the alterations in the water quality after the rupture event. The compliance with both parameters was only achieved after the RO treatment, which acted as an additional barrier to 30 contaminants. The water quality indexes (WQI) suggested that the raw surface water, even eleven months after the incident, was unfit for consumption (WQI: 133.9) whereas the reverse osmosis permeate was ranked as excellent in the rating grid (WQI: 23.7).

Pedestrian evacuation planning under dam-break flood disaster considering road risk and road pedestrian demand

When facing disasters, a well-planned evacuation of people can significantly reduce casualties and disaster losses. Hurricane Katrina struck New Orleans in 2005, causing multiple dam failures and resulting in Lake Pontchartrain flooding back into the city. Taking this disaster as an example, this paper evaluates the risk of pedestrian evacuation on roads during dam-break flood disasters. The evaluation considers three aspects: road evacuation difficulty, disaster risk and road pedestrian demand. The fuzzy VIKOR model was used to evaluate 8 indicators for 50 candidate shelters. A dual-objective planning model was proposed to consider the time-varying and diverse emergency needs of disaster victims. By assessing the risk of pedestrian evacuation on the road and delineating restricted areas, the optimal path distance is calculated. Pareto optimality is then employed to achieve a trade-off between the convenience, cost, and applicability of the evacuation plan. In a complex post-disaster environment, the model can adapt flexibly to emergency rescue situations at various stages by adjusting the parameters in the objective and constraint equation. The Pareto optimal frontier can assist in determining the most suitable solution for the current scenario. In the case of New Orleans, 22 and 18 shelters were respectively selected from 34 candidate shelters for evacuation based on the simulated scenarios.

Emergency action plan for flood disaster mitigation caused by dam failure (case study: Wadaslintang Dam, Indonesia)

The Wadaslintang Dam in Central Java Province is a crucial water storage structure with benefits like irrigation, hydropower, and flood control, which is densely populated downstream. However, the risk of dam failure requires an Emergency Action Plan (EAP) to mitigate flood disasters. The implementation and effectiveness of an Emergency Action Plan protects human lives, help safeguard critical infrastructure, supports economic stability, and fosters community resilience in the face of various emergencies and disasters. This study aims to identify potential risks and consequences associated with the failure of the Wadaslintang dam and its correlation with the EAP. The plan outlines specific steps and procedures to be taken in the event of a dam failure, considering the potential risks and impacts of such an incident and collecting topographic and population data to create evacuation route maps. In conclusion, the EAP for Wadaslintang Dam is essential to minimize risks and protect the affected population during flood disasters. By implementing the plan, coordinating agencies, and ensuring regular updates, the safety and well-being of the population can be safeguarded.

Analysis of Dam Failure and Incident Investigations in the United States from 1960 through 2022: Framework for Improving Future Investigations

Analysis of Dam Failure and Incident Investigations in the United States from 1960 through 2022: Framework for Improving Future Investigations