Damage Risk Assessment Research Articles

Risk assessment of ice dams for water diversion projects based on fuzzy fault trees

Ice dams are among the important risks affecting the operational safety and water conveyance efficiency of water diversion projects in northern China. However, no evaluation indicator system for ice dam risk assessment of water diversion projects has been proposed. Therefore, in this paper, based on the formation mechanism of ice dams, the risk assessment indicator system and the possibility calculation model of ice dams were both proposed for water diversion projects based on the fuzzy fault tree analysis method. The ice dam risk fault tree constructed in this study mainly includes three aspects: ice production, ice transport, and ice submergence conditions. Eighteen basic risk indicators were identified, and 72 minimum cut sets were obtained by using the mountain climb method. Eight risk indicators were determined as the key risk indicators for ice dams, including meteorological conditions, narrowed cross section, sluice incident, erroneous scheduling judgment, ice cover influence, flat bed slope, control structures, and ice flow resistance of piers. Then, the canal from the Fenzhuanghe sluice to the Beijumahe sluice of the Middle Route of the South-to-North Water Diversion Project was taken as the research object. Combined with the expert scoring method, the ice dam risk probability of the canal was determined to be 0.2029 × 10−2, which was defined as a level III risk, which is an occasionally occurring risk. The study results can support ice dam risk prevention and canal system operation in winter for water diversion projects.

Study on the Improved Severity Coefficient Model of Dam Break Consequence Assessment

The assessment of the dam failure consequences is fundamental to the dam risk assessment, and the linear weight sum method is generally used. The comprehensive evaluation of dam failure consequences involves many evaluation factors, the dimensions of each factor are inconsistent. The key is to determine the coefficient of the severity degree of dam failure consequences. Based on the traditional methods, a new severity degree coefficient model of the loss of life, economic losses, environmental impact, and social impact is established after taking the current laws and regulations, the range of the severity of the impact, the establishment of normalized function, the introduction of piecewise function and other factors into comprehensive consideration, and use analysis hierarchy process to obtain weight. Apply the improved linear weighting method to the level assessment and rank of the dam failure consequences of Changlong reservoir, Xialan reservoir, Shibikeng reservoir, Longshan reservoir and Lingtan reservoir in Jiangxi Province, and then determine the grade and rank of dam failure consequences according to the calculation results, analyze the corresponding results accurately combined with expertise. The evaluation results and analysis show that if dam failure occurs, the consequences of the five dams are all very serious, it belongs to extraordinarily serious accidents. The severity degree coefficient of dam failure consequences model can reflect the severity degree of dam failure consequences more objectively and reasonably, and it has clear concept, simple calculation, and intuitive process.

Fatigue damage risk assessment of airport concrete runway based on intelligent algorithm

Fatigue failure issues of runway at airports have become one of core tasks in airport safety management. How to recognize fatigue failure risk factors of concrete runways at airports and implement a quantitative assessment on failure risks of runways is a key topic that is studied in the industrial circle and academic circle at present. For this reason, an integral analysis on internal and external causes of fatigue failure of runways was carried out, which recognized and extracted 18 risk factors. Evaluation values of quantitative risk factors were calculated through a threshold method and evaluation values of qualitative factors were determined by expert scoring. Subsequently, weights of all risk factors were given by G1 method. Finally, the comprehensive risk evaluation value of concrete runways was gained through layer-by-layer coupling. A case study was carried out in the A airport. Results show that the calculated comprehensive risk evaluation value of fatigue failure of concrete runways at airports by the proposed method is basically consistent with engineering objective practical value. The proposed method is expected to be applicable in other airports. The comprehensive risk evaluation value of the concrete runway failure at A airport is 0.49, indicating certain risks of fatigue failure. It is necessary to adopt engineering and management measures according to risk factors with large evaluation values to control the fatigue failure risks. This study concludes that the proposed fatigue failure risk index system of concrete runway of airports is scientific and effective. Moreover, the proposed risk evaluation method is feasible and it provides a new idea and method to fatigue failure risk evaluation of concrete runways at airports.

PENILAIAN RISIKO KEAMANAN BENDUNGAN DI JAWA TIMUR

Dam risk assessment is basically a additional to a standard-based approach, which is a conservative approach to dam engineering. For existing and new dams, dam risk assessment aims to determine whether existing hazard risks can be tolerated, and if hazard risks cannot be tolerated, actions to reduce risk are planned. Risk assessments for existing dams can also be used as a basis for determining priorities in carrying out the required repair or rehabilitation work. This paper discusses the dam risk assessment at Sengguruh Dam, Sutami Dam, Lahor Dam, Wlingi Dam, Bening Dam, Wonorejo Dam and Selorejo Dam. The methods used in risk assessment include the preparation of risk assessments, risk analysis, risk evaluation, risk reduction and management. These seven dams are managed by one manager, namely PJT I and are considered to be representative of this method that can be used to determine the priority value of dam handling. Based on the results of the assessment, the 7 dams fulfill the risk criteria. The next action that can be taken for these dams is to monitor the dam's behavior on a regular basis and in the aftermath of the earthquake, renew and socialize the RTD.

Risk assessment of thermal damage in the event of emergency burning

Problem statement. The task of assessing the risk of thermal damage to people in case of fire is considered. We consider a fire in the railway transport. The task is to determine the temperature fields in a fire and predict the risk of thermal damage to people based on this information. The purpose of the article. Development of a numerical model for assessing the risk of thermal damage to people.Methodology. To simulate the process of thermal pollution of atmospheric air, a two-dimensional energy equation is used. The air velocity field is calculated on the basis of a hydrodynamic model of irrotational flows of an ideal fluid. For the numerical integration of this equation, the Richardson method is used. For the numerical integration of the energy equation, this equation is split into two differential equations. The first equation describes the distribution of temperature due to the movement of air masses. The second equation describes the distribution of temperature due to thermal conductivity. For the numerical integration of the first equation, an implicit difference splitting scheme is used. For numerical integration of the second equation, the Richardson method is used.Scientific novelty.An effective numerical model has been developed that allows the method of computational experiment to determine the risk of thermal injury to people in the event of a fire in the transport corridor. The model is based on the numerical integration of the fundamental equations of hydroaerodynamics and heat and mass transfer. The model allows to take into account the deformation of temperature fields in the air due to the influence of various obstacles. Practical significance. The developed model allows to predict the dynamics of changes in temperature fields in the air that occur during a fire. The model can be used for serial calculations to determine areas of risk of thermal injury to humans. Conclusions. The code for carrying out computational experiment on the basis of the developed numerical models is created. The developed code allows you to quickly, on medium-power computers, calculate the temperature fields generated by a fire. Based on this information, the risk of thermal damage is predicted. The results of a computational experiment are presented.

The utility of fused airborne laser scanning and multispectral data for improved wind damage risk assessment over a managed forest landscape in Finland

Key messageThe potential of airborne laser scanning (ALS) and multispectral remote sensing data to aid in generating improved wind damage risk maps over large forested areas is demonstrated. This article outlines a framework to generate such maps, primarily utilizing the horizontal structural information contained in the ALS data. Validation was done over an area in Eastern Finland that had experienced sporadic wind damage.ContextWind is the most prominent disturbance element for Finnish forests. Hence, tools are needed to generate wind damage risk maps for large forested areas, and their possible changes under planned silvicultural operations.Aims(1) How effective are ALS-based forest variables (e.g. distance to upwind forest stand edge, gap size) for identifying high wind damage risk areas? (2) Can robust estimates of predicted critical wind speeds for uprooting of trees be derived from these variables? (3) Can these critical wind speed estimates be improved using wind multipliers, which factor in topography and terrain roughness effects?MethodsWe first outline a framework to generate several wind damage risk–related parameters from remote sensing data (ALS + multispectral). Then, we assess if such parameters have predictive power. That is, whether they help differentiate between damaged and background points. This verification exercise used 42 wind damaged points spread over a large area.ResultsParameters derived from remote sensing data are shown to have predictive power. Risk models based on critical wind speeds are not that robust, but show potential for improvement.ConclusionOverall, this work described a framework to get several wind risk–related parameters from remote sensing data. These parameters are shown to have potential in generating wind damage risk maps over large forested areas.

EMERGENCY BURNING OF SOLID ROCKET PROPELLANT: DAMAGE RISK ASSESSMENT TO PEOPLE IN THE WORKPLACE

Purpose. This work includes the development of a computer model to calculate the risk of thermal damage to people in the shop in case of emergency burning of solid rocket propellant. Methodology. To calculate the temperature field in the shop in order to determine the zones of thermal damage to workers in the building, the equation expressing the law of energy conservation was used. Based on this modeling equation, the temperature field in the shop is calculated in the presence of a source of heat emission – burning solid rocket propellant. To calculate the velocity field of air flow in the shop, taking into account the location of obstacles in the path of heat wave propagation, we used the model of vortex-free air motion – the equation of the velocity potential. A two-step finite difference scheme of conditional approximation is used to numerically solve the equation for the velocity potential. A difference splitting scheme was used to numerically solve the energy equation. At the first stage of construction of the difference splitting scheme of the two-dimensional energy equation into the system of one-dimensional equations is performed. Each one-dimensional equation allows you to calculate the temperature change in one coordinate direction. The point-to-point computation scheme is used to determine the temperature. When conducting a computational experiment, the air exchange in the building is taken into account. The risk assessment of thermal damage to personnel in the building is performed for different probabilities of the place of emergency combustion of solid rocket propellant. Findings. Using numerical model prediction of the potential risk areas of thermal damage to staff in the shop for a variety of emergency situations was performed. Originality. A computer model for rapid assessment of the potential risk of damage to people in the shop in case of emergency burning of solid rocket propellant was constructed. Practical value. The authors developed a code that allows you to quickly simulate the temperature fields formation in the shop in case of emergency burning of solid rocket propellant and to identify potential areas of thermal damages to workers based on this information. The developed computer program can be used to assess the risk of thermal damage in the chemical industry in case of emergency.

Probabilistic Analysis of Dam Accidents Worldwide: Risk Assessment for Dams of Different Purposes in OECD and Non-OECD Countries with Focus on Time Trend Analysis.

This study presents probabilistic analysis of dam accidents worldwide in the period 1911-2016. The accidents are classified by the dam purpose and by the country cluster, where they occurred, distinguishing between the countries of the Organization for Economic Cooperation and Development (OECD) and nonmember countries (non-OECD without China). A Bayesian hierarchical approach is used to model distributions of frequency and severity for accidents. This approach treats accident data as a multilevel system with subsets sharing specific characteristics. To model accident probabilities for a particular dam characteristic, this approach samples data from the entire data set, borrowing the strength across data set and enabling to model distributions even for subsets with scarce data. The modelled frequencies and severities are combined in frequency-consequence curves, showing that accidents for all dam purposes are more frequent in non-OECD (without China) and their maximum consequences are larger than in OECD countries. Multipurpose dams also have higher frequencies and maximum consequences than single-purpose dams. In addition, the developed methodology explicitly models time dependence to identify trends in accident frequencies over the analyzed period. Downward trends are found for almost all dam purposes confirming that technological development and implementation of safety measures are likely to have a positive impact on dam safety. The results of the analysis provide insights for dam risk management and decision-making processes by identifying key risk factors related to country groups and dam purposes as well as changes over time.

Shedding Light on the Effect of Uncertainties in the Seismic Fragility Analysis of Existing Concrete Dams

The seismic risk assessment of existing concrete gravity dams is of primary importance for our society because of the fundamental role of these infrastructures in the sustainability of a country. The seismic risk assessment of dams is a challenging task due to the lack of case histories, such as gravity dams’ seismic collapses, which hinders the definition of limit states, thus making the application of any conventional safety assessment approach difficult. Numerical models are then fundamental to predict the seismic behaviour of the complex dam-soil-reservoir interacting system, even though uncertainties strongly affect the results. These uncertainties, mainly related to mechanical parameters and variability of the seismic motion, are among the reasons that, so far, prevented the performance-based earthquake engineering approach from being applied to concrete dams. This paper discusses the main issues behind the application of the performance-based earthquake engineering to existing concrete dams, with particular emphasis on the fragility analysis. After a critical review of the most relevant studies on this topic, the analysis of an Italian concrete gravity dam is presented to show the effect of epistemic uncertainties on the calculation of seismic fragility curves. Finally, practical conclusions are derived to guide professionals to the reduction of epistemic uncertainties, and to the definition of reliable numerical models.

Damage risk assessment in historic buildings using equivalent wall-parts

Damage risks in historic buildings are often connected to moisture level, in turn related to temperature. Hence, when damage risk is being assessed, the risk at the points in the geometry of the building where the heat flow is the largest, for instance by the thermal bridges, is of crucial interest. In practice, such assessments may often be based on simulated average conditions of the room air, instead being made for the risk-prone points where the damages are most likely to occur. The reason is that the whole-building simulation tools are generally one-dimensional in their calculations, and unable to deal with the multi-dimensional heat flows at the thermal bridges. Hence the actual damage risk remains unknown, and may be under-estimated to an extent that is impossible to evaluate, without further investigations. Subsequent investigations can be performed for assumed risk-prone points, using two- or three-dimensional simulation tools, but in order to know what points that needs to be scrutinized it would be of value to get a first risk assessment directly in the whole building simulation process. In this article a method, based on the use of equivalent wall-parts, mimicking the performance of the most extreme points of the thermal bridges, is presented. It is displayed how the use of the wall-parts may provide an overview of the risk levels already in the whole-building simulation.

Risk Assessment of Wind Damage to Florests, Based on Wind Velocity and Frequency of Strong Winds

Risk Assessment of Wind Damage to Florests, Based on Wind Velocity and Frequency of Strong Winds

Damage risk assessment of historical asset using laser scan and finite element approach

Most part of valuable art goods are conserved in the Museums, which are in charge of their maintenance and their exposure; some of them, however, have an outdoor location, enriching the artistic and touristic worth of the towns which host them. The art works have an intrinsic vulnerability, due to their irregular shape, slenderness, fragility and – as concerns some sculptures of historical centers – to their oldness. The outdoor artifacts, however, have further hazard sources, since they can hardly be guarded, and they are subjected to possible vandalism actions and lunatic or terrorist attacks.In this work the dynamic response of artifacts to blasts of assigned intensity are investigated on a case-study, i.e. the Fountain of Neptune, located in “Piazza della Signoria”, in Florence. The Fountain of Neptune is a marble and bronze opus made by Bartolomeo Ammannati between 1560 and 1565. The main character of the Fountain, Neptune, is a marble statue 5.7 meters tall, with a weight equal to 11.5 ton. A preliminary laser scanner survey has been made to achieve the geometrical representation of the statue. The considered load condition consists of an explosion caused by 10 kg of TNT placed at 8 meters from the Fountain. The dynamic behavior of the complex under the assumed load has been represented through a numerical analysis, by considering the main statue only - since it is the slenderest element of the complex – and by assuming it as simply supported on the pedestal, without any connector. The obtained results showed the vulnerability of the statue to the assumed blast, and pointed out the role plaid by the contact assumption on its dynamic response.

Wind Damage Risk Assessment Using a Mechanical Model Based on Tree Sway

Wind Damage Risk Assessment Using a Mechanical Model Based on Tree Sway

Sanitary-hygienic characteristics of health risk and clinical assessment of damage to health done to population living in a specific geochemical province under long-term exposure to arsenic introduced with drinking water

Sanitary-hygienic characteristics of health risk and clinical assessment of damage to health done to population living in a specific geochemical province under long-term exposure to arsenic introduced with drinking water

ОЦЕНКИ РИСКОВ И УЩЕРБОВ КАК ИНСТРУМЕНТ СОЦИАЛЬНОЙ ЭКОЛОГИИ

Социальная экология – это знание, которое сочетает в себе естественнонаучный и гуманитарный профили. Естественнонаучная составляющая содержит в себе анализ рисков и оценку экологических ущербов (инструменты рационального природопользования). «Анализ риска» определяется как меж- и многодисциплинарная наука и практическая деятельность, изучающая вероятности рисков для личности, общества, государства и частных предприятий на местном, региональном, национальном или глобальном уровнях. В качестве примера рассматривается вероятностная модель риска недостижения климаксового состояния экосистемой. Экологический ущерб – это уменьшение полезности окружающей среды вследствие её загрязнения или иного изменения. В качестве примера рассматриваются оценки рыбохозяйственного ущерба пресноводным экосистемам в результате антропогенных воздействий.

A Step-Wedge in the Biochemical Diagnosis of Preeclampsia

Preeclampsia, a hypertensive disorder of pregnancy, is one of the leading causes of maternal and neonatal morbidity and mortality worldwide. Among the reasons for the great global burden of disease is the poor predictive value of high blood pressure and proteinuria (traditional markers for the disease) for related adverse outcomes (1). Angiogenic biomarkers developed and studied during the past decade are widely recognized as clinically sensitive and specific biomarkers, with excellent predictive values during the third trimester that complement and improve upon clinical signs and symptoms (2). Normally produced in pregnancy, soluble FMS-like tyrosine kinase (sFLT1) is a placentally produced, antiangiogenic protein that mitigates rapidly progressing placental angiogenesis driven by proangiogenic proteins—placental growth factor (PlGF) and vascular endothelial growth factor—in the latter third of gestation. Preeclampsia is characterized by enhanced production of placental sFLT1, which in turn binds to PlGF, causing the free concentration of serum PlGF to fall. Increased circulating sFLT1 and decreased free PlGF antedate the onset of preeclamptic signs and symptoms, allowing for accurate and minimally invasive risk assessment of the systemic vascular damage that characterizes preeclampsia (2). Furthermore, angiogenic biomarkers can be used to differentiate preeclampsia from mimickers of disease, such as chronic hypertension, gestational hypertension, and chronic kidney disease (2). Despite the opportunity for early identification of disease before the onset of signs and symptoms, funding bodies have been reluctant to invest in the head-to-head comparisons of angiogenic biomarkers vs traditional factors, leading to a …

Cumulative noise exposure model for outdoor shooting ranges.

An impulsive noise exposure model for outdoor military shooting ranges was created. The inputs to the model included spatial interpolation of noise exposure metrics measured from a single round of fire from a small-arms ballistic weapon. Energies from this single-shot model were spatially translated and summed to simulate multiple shooters firing multiple rounds based on the equal energy hypothesis for damage risk assessment. A validation measurement was performed, and the uncertainties associated with measurement and modeling were shown to be acceptably low. This model can predict and assess total exposures and protection measures for shooters, instructors, and other range personnel.

Quantitative micro-scale flood risk assessment in a section of the Trotuș River, Romania

This paper focuses on the estimation of direct damages caused by three flood scenarios with different return periods in the section Făgetul de Sus – Ghimeş – Palanca Pass of Trotuș River, with the aim of highlighting the need of improved land use plans. The damage for three land use classes (residential building, infrastructure and agriculture) were estimated using the damage curves developed by the European Joint Research Centre (JRC) as well as site specific maximum damage values. The data were processed with the help of the ArcMap 10.2 software and FloodRisk tool from QGIS software. Furthermore, the flood risk was assessed using the damage – probability curves, which associates the damage with the corresponding frequency of occurrence. This method was identified and adapted to the characteristics of the study area in order to develop a methodology of flood risk assessment that is answering the question: does the lack of land use plans increase the vulnerability and the flood damage? The results showed that the greatest damages are registered for the residential building land use class for a flood probability of 0.001. In this case the damages reach up to 60% on the scale range of deterioration factor, the total damage value being 2 million euros. For the same hazard probability the total registered damage value for roads is 7500 euro, for railways is around 12,000 euro, while for agriculture is around 84,000 euro. These results highlight the need of protection measures and land use plans development and implementation. Regarding the protection measures we consider that the egalitarianism would be the concept that should be applied in the study area and also an improved cooperation between government, specialized agencies and local authorities at local level would lead to a more efficient flood risk management process. The proposed methodology can be applied for micro-scale analysis, providing quantitative results regarding the flood damage and flood risk assessment. It includes a detailed vulnerability analysis of the elements-at-risk with the aim of developing a more comprehensive approach of flood risk assessment.

A Data-Driven Approach Based on Multivariate Copulas for Quantitative Risk Assessment of Concrete Dam

Risk assessment of dam’s running status is an important part of dam management. A data-driven method based on monitored displacement data has been applied in risk assessment, owing to its easy operation and real-time analysis. However, previous data-driven methods considered displacement data series at each monitoring point as an independent variable and assessed the running status of each monitoring point separately, without considering the correlation between displacement of different monitoring points. In addition, previous studies assessed the dam’s running status qualitatively, without quantifying the risk probability. To solve the above two issues, a displacement-data driven method based on a multivariate copula function is proposed in this paper. Multivariate copula functions can construct a joint distribution which reveals the relevance structure of random variables. We assumed that the risk probability of each dam section is independent and took monitoring points at one dam section as examples. Starting from the risk assessment of single monitoring points, we calculated the residual between the monitored displacement data and the modelled data estimated by the statistical model, and built a risk ratio function based on the residual. Then, using the multivariate copula function, we obtained a combined risk ratio of multi-monitoring points which took the correlation between each monitoring point into account. Finally, a case study was provided. The proposed method not only quantitatively assessed the probability of the real-time dam risk but also considered the correlation between the displacement data of different monitoring points.

Damage risk assessment of a high-rise building against multihazard of earthquake and strong wind with recorded data

The high-rise buildings designed with a long lifetime may be exposed to one or more extreme hazards. Traditionally, specifications separately treated the multiple extreme hazards according to the controlling load case. Thus, the ability of high-rise buildings designed by the current codes to face the combined threats of earthquake and wind is rather vague. This paper presents a multihazard-based framework to assess the damage risk of a high-rise building subjected to earthquake and wind hazards separately and concurrently, which can be broken into three parts: the modeling of hazards, the structural fragility analysis and the damage probability computation. Firstly, based on the earthquake and wind data from 1971 to 2017 recorded in the Dali region of China, the hazard curves of single earthquake and wind, and the copula-based surface of bi-hazards are well established. Secondly, the multihazard-based fragility analysis of a high-rise building in Dali Prefecture is performed with the consideration of various load conditions. Lastly, upon completing the hazard models and fragility analyses, quantifications of the damage probabilities for the separate and concurrent hazards are determined directly. Numerical results indicate that the damage probability and contributions of each hazard circumstance are sensitive to damage severity. Furthermore, the damage probability induced by the bi-hazards dominates the total probability under most damage states conflicted with the common assumptions presented in the available researches. The comprehensive application highlights the necessity of examining the responses of high-rise buildings subjected to multihazard. The potential of the presented framework is of great help for decision-making.