Explore the vast range of titles available.

The aim of this study is to analyze the effects of a possible dam failure under various scenarios and to generate a flood hazard map for two consecutive dams located in a study area with a dense-residential region and a heavy-traffic highway. Two consecutive dams consist of Elmalı 2, a concrete-buttress dam and Elmalı 1, an earth-fill gravity dam in the upstream and downstream, respectively. Hydrologic Engineering Center-River Analysis System (HEC-RAS) was used to develop a dam failure model. Dam failure scenarios were examined regarding three main criteria: the Breach Formation Time (BFT), the Number of Failed Buttresses (NFB) of Elmalı 2, and the Reservoir Volume Ratio (RVR) of Elmalı 1. Accordingly, flood peak depth (Hp), peak flow rate (Qp), peak velocity (vp), and time to reach the peak (tp) are discussed. The results showed that BFT and NFB of Elmalı 2 were highly effective on these values, whereas RVR of Elmalı 1 had no significant effect. Moreover, the total area affected by potential floods was calculated with a comparative areal change analysis using flood inundation and flood hazard maps obtained. Estimated damage costs indicate that in the worst-case scenario, more than 500 buildings will be affected in the region.

On a global scale, the demand for mineral products has increased substantially with economic development. Consequently, the mining of mineral resources results in the production and accumulation of a large number of tailings, causing many problems with respect to mining, the environment, and the economy. In the mining process, tailings must be reasonably treated to prevent them from entering the water cycle through rivers. The storage of tailings under water can effectively hinder the chemical reactions that they undergo. Therefore, it is a critical practice to store these substances in ponds or impoundments behind dams. However, tailings dams frequently fail, resulting in the discharge of significant quantities of tailings into the natural environment, thereby causing grievous casualties and serious economic losses. This paper discusses reasons including seepage, foundation failure, overtopping, and earthquake for tailings dam failures and explores failure mechanisms by referring to the available literature. This research has determined that the failure of tailings dams is closely related to the state of the country’s economy. Most of the tailings dam breakages in developed countries occurred decades ago. In recent years, the proportion of tailings dam failures in developing countries has been relatively high. Considering the serious damages caused by tailings dam breakage, it is important to understand the main reasons and mechanisms for their failure. The purpose of this review is to provide a reference for the design and construction to the building of the tailing dams and to reduce the occurrences of their failure.

There are numerous influencing factors of the risk consequences of dam break. The scientific and reasonable index system and its weight distribution are some of the key elements for comprehensive evaluation of the dam break risk. Taking into consideration 20 factors, including hazards, exposure and vulnerability, the evaluation index system of the consequences of dam break risk is constructed. Using the Statistical Cloud Model (SCM) to improve the entropy method, we establish the weight calculation model of the influencing factors of dam break risk consequences. The results shows that the top five factors with the highest weight are risk population, flood intensity, alert time, risk understanding and distance from the dam. Compared to traditional algebraic weight calculation methods, the result is basically consistent with the algebraic weight distribution, and increases the range by 2.03 times, supporting a more scientific basis for recognizing and evaluating dam break risk consequences.

Dam failures are examples of man-made disasters that have stimulated investigation into the processes related to the failure of different dam types. Embankment dam breaching during an overtopping event is one of the major modes of failure for this dam type, comprising both earthfill and rockfill dams. This paper presents the results of a series of laboratory tests on breach initiation and progression in rockfill dams. Especially eight breaching tests of 1 m-high 1:10 scale embankment dams constructed of scaled well-graded rockfill were conducted. Tests were performed with and without an impervious core and under different inflow discharges. Controlling instrumentation includes up to nine video cameras used for image analysis and photogrammetry. A previously little-used technique of dynamic 3D photogrammetry has been applied to prepare 3D models every 5 s throughout the breaching process, allowing us to track in detail breach development. These dynamic 3D models along with pressure sensor data, flow data, and side-view video are used to provide data on erosion rates throughout the breaching process. One important purpose of this research is to test methods of observing a rapidly changing morphology such as an embankment dam breach that can easily be scaled up to large-scale and prototype-scale tests. The resulting data sets are further intended for the verification of existing empirical and numerical models for slope stability and breach development as well as the development of new models.

In the dark of a July night in 2018, a 5-billion-cubic-metre torrent of muddy water crashed through rooftops and ripped through the downstream villages of southeast Lao People’s Democratic Republic (Lao PDR). An auxiliary “saddle” dam had collapsed in the US$1.02 billion Xe Pian-Xe Namnoy (XPXN) Hydropower Project that was still under construction and had just reached financial contractual close five years prior, in 2013. In the aftermath of the collapse, official state narratives pointed to extreme weather conditions and “unforeseen” construction and engineering miscalculations, viewing soil conditions as the primary culprit. This paper examines the financial dimensions of dam failure and introduces the term “fast finance”: financier-driven timelines that have drastically expedited and shortened the legal, social, and pre-construction processes involved in hydropower dam projects to the detriment of dam safety, due diligence, and local participatory input. Extreme weather and anthropogenic climate change are not sole explanatory factors in the XPXN dam disaster. This paper highlights the also significant role of financial and political interests as contributing factors in dam safety and failure alongside extreme weather. The paper challenges conventional “natural disaster” framing of dam collapse by bringing into focus ex-ante political decision-making, financial engineering, and construction planning prior to dam construction to highlight the ways in which the XPXN catastrophe also had anthropogenic and “unnatural” contributing factors. Fast finance encompasses the role of temporality and the responsibility of state-business actors in ex-ante financial and infrastructure decisions that conclude with catastrophic outcomes. The article examines the re-engineering of contemporary dam finance through a case study of Lao PDR and argues that issues of financial engineering should be examined alongside other forms of civil, mechanical, structural, and hydrological engineering in the analysis of dam disasters. The temporal logics of financial actors—particularly the financialized logic of fast finance—has displaced the public-good-producing logic of patient capital. Financial logics shape and condition other forms of engineering and construction and are central to considerations of dam safety and accountability. Naturalizing discourses around extreme weather and aging dams deflect from the financial decisions and policy action, or inaction, of state-business actors to prevent dam collapse.

This study investigates the impacts of extreme rainfall variations on dam safety, focusing on six large Dam Failure (DF) events in India: Tigra, Khadakwasla, Pagara, Machu-2, Koyana, and Kaddem. Daily gridded rainfall data is obtained from the India Meteorological Department, and the Inverse Distance Weighted interpolation method is used to get location-specific daily rainfall data. The severity of extreme rainfall events on dam safety is highlighted by computing the average rainfall (AR) and accumulated rainfall (ACR) for 5-, 10-, and 15-day prior to the date of DF. Shockingly, the magnitude of 15-day ACR prior to DF exceeds 50% of the normal annual rainfall at most of the study locations. This unexpected situation may put tremendous pressure on the dams and eventually lead to their failure. Further, the Probable Maximum Precipitation (PMP) is computed at each dam location using the Annual Maximum Daily Precipitation (AMDP) time series across 121 years. Next, the Efficiency Factor (EF) is calculated to check the severity of rainfall prior to the DF. The annual EF values are computed, and the maximum EF value over 121 years indicates the maximum rainy day in that time horizon. The value of EF above 0.85 poses a threat to dams, and approaching 1.0 (almost equal to PMP) could result in DF. This study established a robust correlation between dam failures and heavy rainfall preceding them. Some dams, like Machu-2, Kaddem, and Pagara, experienced clear rainfall peaks on the day of the collapse, indicating heavy rainfall over 5 days (5-day ACR) as the primary cause. Others, such as Tigra and Khadakwasla exhibited continuous moderate rainfall (ACR) for 5 to 10 days is the principal cause of failure. These findings are of significant relevance to professionals in the field of dam engineering, offering a comprehensive understanding of how extreme rainfall events can impact dam failures and providing valuable insights into rainfall patterns and their implications for dam safety. Most importantly, the dam owners will be notified at least 5 days prior to the catastrophe (dam failure), which is sufficient to take suitable measures for safe reservoir operations.

Check dams can be effective in reducing debris-flow hazards, however their failure could have serious consequences for people and infrastructures and should be avoided. The examination of these failures embracing a forensic engineering analysis, still rather poorly represented in the scientific literature, would lead to important improvements in how residual risk is planned and managed. In this study, we developed a framework for the forensic analysis of check dam systems failures in terms of cascading natural-anthropogenic hazards, and we applied such framework to a catastrophic event that occurred in October 2018 in the Rotian creek catchment (Eastern Italian Alps). The post-event survey and analysis gathered observations about rainfall, peak discharges, morphological impacts, and damaged check dams. Based on these data, we applied a newly developed coupled hydrologic-hydraulic debris flow model and we assessed the failure mode of the check dam system. Our results highlight important practical implications for improving residual risk management, namely: (i) the development of debris flow models capable of simulating the role of check dams and their failure in the debris flow dynamics, (ii) the call for extensive datasets of check dam system failures, and (iii) the necessity to develop methodologies for the prioritisation of field inspection and maintenance of existing check dam systems.

Earthen dams are exposed to complex environments where their safety is often affected by multiple uncertain risks. A Bayesian network (BN) is often used to analyze the dam failure risk, which is an effective tool for this issue as its excellent ability in representing uncertainty and reasoning. The validity of the BN model is strongly dependent on the quality of the sample data, making convincing modeling rationale a challenge. There has been a lack of systematic analysis of the dam failure data of China, resulting in limited exploration of the potential associations between risk factors. In this paper, we established a comprehensive database containing various dam failure cases in China. Herein, historical dam failure statistics are used to develop BN models for risk analysis of earthen dams in China. In order to unleash the value of the historical data, we established a Bayesian network through the Causal Loop Diagrams (CLD) based on the nonlinear causal analysis. We determined the conditional probabilities using Word Frequency Analysis (WFA). By comparing with the Bayesian Learning results, the modeling method of BN proposed in our study has apparent advantages. According to the BN model established in this paper, the probabilities of dam failure due to seepage damage, overtopping, and structural instability are estimated to be 22.1%, 58.1%, and 7.9%, respectively. In addition, we presented a demonstration of the inference process for the dam failure path, which will offer valuable insights to dam safety practitioners during their decision-making process.

Urban expansion results in a large number of land creation projects in the Chinese Loess Plateau. This has strikingly catalyzed hilltops being cut and valleys or low lands being filled by bulldozed mountain. Meanwhile, a large number of check dams were built into the loess gully to store soil and water. This paper studied a case of check dam failure, which resulted in rapid loess mudflow in a bulldozed mountain area. To investigate kinematic characteristics of the mudflow and trigger mechanism of the dam failure, in situ feature measurements, physical property tests, triaxial tests, and groundwater simulations were carried out. The field investigation revealed that moisture content of the loess in the filled area was very high and that the dam failure was most likely due to groundwater seepage. The VS2DI simulation of the check dam showed that its material was over saturated due to moisture migration in it, which significantly affected its stability. The simulation results are consistent with those of the field investigation. Rapid mobility of the mudflow could be attributed to liquefaction of the loess behind the dams. Meanwhile, the movement velocities calculated from by in situ mud splash height are related to the deposited volume of the mobilized materials at corresponding sites.

Different regions worldwide have adopted various approaches to tailings management, as a result of the site settings and local practices as they have evolved. Tailings dam failures have continued to occur in both developing and developed countries, necessitating a range of tailings management approaches. These failures, while rare, continue to occur at a frequency that exceeds both industry and society expectations, and there is much to be learned from well-documented cases. Tailings management continues to be overly reliant on a net present value approach using a high discount factor, rather than a whole-of-life approach that may result in safer and more stable tailings facilities and may also facilitate the eventual mine closure. There is a need for the further development and implementation of new tailings management technologies and innovations, and for the application of whole-of-life costing of tailings facilities. Changes in tailings management will most readily be achieved at new mining projects, making change across the minerals industry a generational process.