scholarly journals Reviewing Arch-Dams’ Building Risk Reduction Through a Sustainability–Safety Management Approach

2020 ◽  
Vol 12 (1) ◽  
pp. 392 ◽  
Author(s):  
Enrico Zacchei ◽  
José Luis Molina

The importance of dams is rapidly increasing due to the impact of climate change on increasing hydrological process variability and on water planning and management need. This study tackles a review for the concrete arch-dams’ design process, from a dual sustainability/safety management approach. Sustainability is evaluated through a design optimization for dams´ stability and deformation analysis; safety is directly related to the reduction and consequences of failure risk. For that, several scenarios about stability and deformation, identifying desirable and undesirable actions, were estimated. More than 100 specific parameters regarding dam-reservoir-foundation-sediments system and their interactions have been collected. Also, a summary of mathematical modelling was made, and more than 100 references were summarized. The following consecutive steps, required to design engineering (why act?), maintenance (when to act) and operations activities (how to act), were evaluated: individuation of hazards, definition of failure potential and estimation of consequences (harm to people, assets and environment). Results are shown in terms of calculated data and relations: the area to model the dam–foundation interaction is around 3.0 Hd2, the system-damping ratio and vibration period is 8.5% and 0.39 s. Also, maximum elastic and elasto-plastic displacements are ~0.10–0.20 m. The failure probability for stability is 34%, whereas for deformation it is 29%.

Author(s):  
Jose-Luis Molina ◽  
Enrico Zacchei

The are thousands of large dams over the globe. The importance of dams is rapidly increasing due to the impact of climate change on increasing hydrological process variability and on water planning and management need. This study tackles a review for the concrete arch-dams’ design process, from a dual sustainability/safety management approach. On one hand, Sustainability is evaluated through a design optimization for dams´ stability and deformation analysis. On the other hand, safety is directly related to the reduction and consequences of failure risk. For that, several scenarios about stability and deformation, identifying desirable and undesirable actions, were estimated. More than 100 specific parameters regarding dam-reservoir-foundation-sediments system and their interactions have been collected. Also, a summary of mathematical modelling was made, and more than 100 references were summarized. The following consecutive steps, required to design engineering (why act?), maintenance (when to act) and operations activities (how to act), were evaluated: individuation of hazards, definition of failure potential and estimation of consequences (harm to people, assets and environment). Results show that the area to model the dam–foundation interaction is around 3.0 Hd2, the system-damping ratio and vibration period is 8.5% and 0.39 s. Also, maximum elastic and elasto-plastic displacements are ~0.10–0.20 m. The failure probability for stability is 34%, whereas for deformation it is 29%


2004 ◽  
Vol 31 (4) ◽  
pp. 703-711 ◽  
Author(s):  
H P Hong ◽  
J Jiang

A systematical assessment of the impact of the uncertainty in the natural vibration period and damping ratio on the peak displacement of linear elastic and elastoplastic single-degree-of-freedom systems is carried out using more than 200 strong ground-motion records. The assessment is based on the ratio of the peak inelastic displacement with uncertain structural properties to the peak linear elastic displacement and, the ratio of the peak linear elastic displacement to the yield displacement. Statistical analysis for the ratios obtained is presented. The analysis results indicate that the impact of the uncertainty in the damping ratio on these ratios is less significant than that of the uncertainty in the natural vibration period. The results also show that the consideration of uncertainty in the natural vibration period slightly alters the average peak displacement of the linear or elastoplastic systems. However, the coefficients of variation of these ratios change significantly, especially, if the mean of the natural vibration period is less than about 0.1 s. Simple to use empirical equations, based on the results obtained, are suggested in evaluating the mean and the coefficient of variation of the ratios considering the uncertainty in structural properties. Key words: seismic excitation, uncertainty, peak elastic displacement, peak inelastic displacement.


2021 ◽  
Vol 09 (03) ◽  
pp. E348-E355
Author(s):  
David L. Diehl ◽  
Harshit S. Khara ◽  
Nasir Akhtar ◽  
Rebecca J. Critchley-Thorne

Abstract Background and study aims The TissueCypher Barrett’s Esophagus Assay is a novel tissue biomarker test, and has been validated to predict progression to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC) in patients with Barrett’s esophagus (BE). The aim of this study was to evaluate the impact of TissueCypher on clinical decision-making in the management of BE. Patients and methods TissueCypher was ordered for 60 patients with non-dysplastic (ND, n = 18) BE, indefinite for dysplasia (IND, n = 25), and low-grade dysplasia (LGD, n = 17). TissueCypher reports a risk class (low, intermediate or high) for progression to HGD or EAC within 5 years. The impact of the test results on BE management decisions was assessed. Results Fifty-two of 60 patients were male, mean age 65.2 ± 11.8, and 43 of 60 had long segment BE. TissueCypher results impacted 55.0 % of management decisions. In 21.7 % of patients, the test upstaged the management approach, resulting in endoscopic eradication therapy (EET) or shorter surveillance interval. The test downstaged the management approach in 33.4 % of patients, leading to surveillance rather than EET. In the subset of patients whose management plan was changed, upstaging was associated with a high-risk TissueCypher result, and downstaging was associated with a low-risk result (P < 0.0001). Conclusions TissueCypher was used as an adjunct to support a surveillance-only approach in 33.4 % of patients. Upstaging occurred in 21.7 % of patients, leading to therapeutic intervention or increased surveillance. These results indicate that the TissueCypher test may enable physicians to target EET for TissueCypher high-risk BE patients, while reducing unnecessary procedures in TissueCypher low-risk patients.


2020 ◽  
pp. 021849232098432
Author(s):  
Wahaj Munir ◽  
Jun Heng Chong ◽  
Amer Harky ◽  
Mohamad Bashir ◽  
Benjamin Adams

Acute type A aortic dissection is a surgical emergency and management of such pathology can be complex with poor outcomes when there is organ malperfusion. Carotid artery involvement is present in 30% of patients diagnosed with acute type A aortic dissection, and given its emergency and complex nature, there is much controversy regarding the approach, extent of treatment, and timing of the intervention. It is clear that the occurrence of cerebral malperfusion adds an extra layer of complexity to the decision-making framework for treatment. Standardization and validation of the optimal management approach is required, and this should ideally be addressed with large-scale studies. Nonetheless, current literature supports the need for rapid recognition and diagnosis of acute type A aortic dissection with cerebral malperfusion, immediate and extensive surgical repair, and the appropriate use of cerebral perfusion techniques. This paper aims to discuss the current evidence regarding the impact of carotid artery involvement in both the management and outcomes of acute type A aortic dissection.


2020 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
Tianshi Pan ◽  
Lijun Zuo ◽  
Zengxiang Zhang ◽  
Xiaoli Zhao ◽  
Feifei Sun ◽  
...  

The implementation of ecological projects can largely change regional land use patterns, in turn altering the local hydrological process. Articulating these changes and their effects on ecosystem services, such as water conservation, is critical to understanding the impacts of land use activities and in directing future land planning toward regional sustainable development. Taking Zhangjiakou City of the Yongding River as the study area—a region with implementation of various ecological projects—the impact of land use changes on various hydrological components and water conservation capacity from 2000 to 2015 was simulated based on a soil and water assessment tool model (SWAT). An empirical regression model based on partial least squares was established to explore the contribution of different land use changes on water conservation. With special focus on the forest having the most complex effects on the hydrological process, the impacts of forest type and age on the water conservation capacity are discussed on different scales. Results show that between 2000 and 2015, the area of forest, grassland and cultivated land decreased by 0.05%, 0.98% and 1.64%, respectively, which reduces the regional evapotranspiration (0.48%) and soil water content (0.72%). The increase in settlement area (42.23%) is the main reason for the increase in water yield (14.52%). Most land use covered by vegetation has strong water conservation capacity, and the water conservation capacity of the forest is particularly outstanding. Farmland and settlements tend to have a negative effect on water conservation. The water conservation capacity of forest at all scales decreased significantly with the growth of forest (p < 0.05), while the water conservation capacity of different tree species had no significant difference. For the study area, increasing the forest area will be an effective way to improve the water conservation function, planting evergreen conifers can rapidly improve the regional water conservation capacity, while planting deciduous conifers is of great benefit to long-term sustainable development.


2015 ◽  
Vol 7 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Joanne Taylor ◽  
Jean Pierre Garat ◽  
Samer Simreen ◽  
Ghida Sarieddine

Purpose – This paper aims to outline the food safety roles and responsibilities within the industry that play an important role in the success of government initiatives, demonstrated using a new model of Food Safety Culture Excellence. It is the sixth article in a Worldwide Hospitality and Tourism Themes theme issue presenting a comprehensive government strategy for improving food safety management standards across the hospitality industry. Design/methodology/approach – A case study is used to demonstrate the impact of auditing the 16 dimensions of Food Safety Culture Excellence in practice. The business selected was the first in Abu Dhabi to achieve regulatory compliance for HACCP-based food safety management, and the first to conduct a Food Safety Culture Excellence audit in the United Arab Emirates. Findings – This article demonstrates how the concept of food safety culture works in practice, using the Food Safety Culture Excellence Model with four categories and 16 dimensions. It demonstrates how the auditing of culture within a business can highlight strengths and weaknesses and facilitate continual improvement. Originality/value – The article represents the first published model of Food Safety Culture Excellence, an extensively researched and tested model developed by Taylor Shannon International Ltd. and launched in conjunction with Campden BRI in 2014. It also demonstrates the first audit of the model in practice.


Author(s):  
А.О. РЕНЗЯЕВ ◽  
О.П. РЕНЗЯЕВ ◽  
С.Н. КРАВЧЕНКО ◽  
Р.В. КРЮК

Исследованы прочностные и физико-механические свойства оболочки рапса с точки зрения ее разрушения и удаления. Установлено, что наиболее рациональным является двухстадийный способ обрушивания: 1-я стадия – на вальцовых мельницах, 2-я – на центробежной обрушивающей машине. Определены параметры центробежной обрушивающей машины для обеспечения минимальной необходимой линейной скорости 10,81 м/с: угол наклона отбойной пластины (90 ± 2)°, частота вращения барабана (2400 ± 150) об/мин. Установлено, что правильно подобранные условия и угол, под которым происходит удар, позволяют значительно снизить количество не до конца обрушенного семени и содержание расколотого ядра. При этом при свободном ударе об отбойную пластину под углом, отличным от 88–91°, или подаче недостаточно равномерного потока семян значительно увеличивается содержание необрушенных семян. На разрушение 1 кг семян необходимо затратить 58,45 Дж. Таким образом, по расчетным данным, для семян рапса диаметром 1,5 мм частота вращения барабана должна находиться в диапазоне от 2221 до 2565 об/мин при ударе семени под углом 90°. Диаметр семян рапса, выращиваемого в Сибирском регионе, составляет от 0,8 до 1,8 мм. Установлено, что подсушивание семян рапса в течение 30–40 с при температуре 100°С позволяет увеличить эффективность разрушения оболочки до полного ее отделения от ядра рапса. Представленные результаты позволяют повысить качество очистки семян рапса от оболочки и улучшить качественные характеристики получаемого масла, облегчить последующие технологические процессы получения пищевого масла, снизить затраты на рафинацию и дезодорацию на 2%. The strength and physico-mechanical properties of the shell of rapeseed in terms of its destruction and removal are investigated. It is established that the most rational is a two-stage method of seed hulling: the 1st stage – on roller mills, the 2nd – on a centrifugal hulling machine. The parameters of the centrifugal hulling machine to provide the minimum required linear speed of 10,81 m/s are defined: the angle of inclination of the turnback plate (90 ± 2)°, the rotational speed of drum (2400 ± 150) RPM. It is established that the correctly selected conditions and the angle at which the impact occurs, can significantly reduce the amount is not completely hulling seed and the substance of the split nucleus. At the same time, with a free impact on the turnback plate at an angle different from 88–91°, or the supply of an insufficiently uniform flow of seeds, the content is not completely hulling seed increases significantly. On hulling of 1 kg of seeds it is necessary to spend 58,45 J. Thus, according to the calculated data, for rape seeds with a diameter of 1,5 mm, the rotational speed of drum should be in the range from 2221 to 2565 RPM when the seed is struck at an angle of 90°. The diameter of rapeseed grown in the Siberian region ranges from 0,8 to 1,8 mm. It was found that drying of rapeseed for 30–40 s at a temperature of 100°C, can increase the efficiency of destruction of the shell to its complete separation from the core of rapeseed. The presented results make it possible to improve the quality of cleaning of rape seeds from the shell and improve the quality characteristics of the obtained oil, facilitate the subsequent technological processes of obtaining edible oil, reduce the cost of refining and deodorization by 2%.


2021 ◽  
Author(s):  
Nassima Brown ◽  
Adrian Brown ◽  
Abhijeet Degupta ◽  
Barry Quinn ◽  
Dustin Stringer ◽  
...  

Abstract As the oil and gas industry is facing tumultuous challenges, adoption of cutting-edge digital technologies has been accelerated to deliver safer, more efficient operations with less impact on the environment. While advanced AI and other digital technologies have been rapidly evolving in many fields in the industry, the HSE sector is playing catch-up. With the increasing complexity of risks and safety management processes, the effective application of data-driven technologies has become significantly harder, particularly for international organizations with varying levels of digital readiness across diverse global operations. Leaders are more cautious to implement solutions that are not fit-for purpose, due to concerns over inconsistencies in rolling out the program across international markets and the impact this may have on ongoing operations. This paper describes how the effective application of Artificial intelligence (AI) and Machine Learning (ML) technologies have been used to engineer a solution that fully digitizes and automates the end-to-end offshore behavior-based safety program across a global offshore fleet; optimizing a critical safety process used by many leading oil & gas organization to drive positive workplace safety culture. The complex safety program has been transformed into clear, efficient and automated workflow, with real-time analytics and live transparent dashboards which detail critical safety indicators in real time, aiding decision-making and improving operational performance. The novel behavior-based safety digital solution, referred to as 3C observation tool within Noble drilling, has been built to be fully aligned with the organization's safety management system requirements and procedures, using modern and agile tools and applications for fully scalability and easy deployment. It has been critical in sharpening the offshore safety observation program across global operations, resulting in a boost of the workforce engagement by 30%, and subsequently increasing safety awareness skill set attainment; improving overall offshore safety culture, all while reducing operating costs by up to 70% and cutting carbon footprint through the elimination of 15,000 manhours and half a million paper cards each year, when compared to previously used methods and workflows


2011 ◽  
Vol 15 (5) ◽  
pp. 1379-1386 ◽  
Author(s):  
T. Nehls ◽  
Y. Nam Rim ◽  
G. Wessolek

Abstract. Due to climate change, cities need to adapt to changing rainfall and rainwater run-off dynamics. In order to develop an corresponding process based run-off model for pavements, we had to improve the measurement technique to detect run-off dynamics in an appropriate high resolution. Traditional tipping buckets (TB) have a comparable low volume resolution, capable to quantify the highest intensities in a range of expected flows. This results in varying temporal resolutions for varying flow intensities, especially in low resolutions for small flow events. Therefore, their applicability for run-off measurements and other hydrological process studies is limited, especially when the dynamics of both small and big flow events shall be measured. We improved a TB by coupling it to a balance and called it weighable tipping bucket (WTB). This paper introduces the device set up and the according data processing concept. The improved volume and temporal resolution of the WTB are demonstrated. A systematic uncertainty of TB measurements compared to WTB measurements is calculated. The impact of that increased resolution on our understanding of run-off dynamics from paved urban soils are discussed, exemplary for the run-off and the surface storage of a paved urban soil. The study was conducted on a permeably paved lysimeter situated in Berlin, Germany. Referring to the paved surface, the TB has a resolution of 0.1 mm, while the WTB has a resolution of 0.001 mm. The temporal resolution of the WTB is 3 s, the TB detects individual tippings with 0.4 s between them. Therefore, the data processing concept combines both the benefits of the balance to measure small intensities with that of the TB to measure high flow intensities. During a five months period (July to November 2009) 154 rain events were detected. Accordingly, the TB and WTB detected 47 and 121 run-off events. The total run-off was 79.6 mm measured by the WTB which was 11 % higher than detected by the TB. 95 % of that difference can be appointed to water, which evaporated from the TB. To derive a surface storage estimation, we analyzed the WTB and TB data for rain events without run-off. According to WTB data, the surface storage of the permeable pavement is 1.7 mm, while using TB data leads to an overestimation of 47 % due to low volume resolution of the TB. Combining traditional TB with modern, fast, high resolution digital balances offers the opportunity to upgrade existing TB systems in order to improve their volume detection limit and their temporal resolution, which is of great advantage for the synchronization of water balance component measurements and the investigation of hydrological processes. Furthermore, we are able to quantify the uncertainty of flow measurements gained with traditional tipping buckets.


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