Regional Design Storm and Flood Modelling—Risk Implications in Ungauged Catchments

Most planned developments in a catchment for control of excess water using a culvert, bridge or dam spillway are located at a site in a stream where there are no discharge measurements. Even though, for gauged catchments a number of established flood frequency models and rainfall-runoff models do exist, for ungauged catchments mostly regional flood frequency and event-based rainfall-runoff models are used, which depend on regional parameters. In this paper, a regional approach for design floods is presented and risk implication for design of drainage structures assessed. A case study in light of the above has been considered at four ungauged sites in the Limpopo Drainage Basin in north-eastern Botswana.

Reducing risks in the investigation, design and construction of large concrete dams

An overview of the GeoSafe 2016 Symposium topic is provided using the example of large concrete dams for purposes of illustration.It is essential that the risks associated with large dams be evaluated rigorously and managed proactively at all stages of their lives so that the risk of failure remains As Low As Reasonably Practicable(ALARP).Rock engineering features of large concrete dams that require particular attention,assessment and monitoring during the investigation,design,construction,initial filling,inservice operation,and subsequent repair and upgrade stages of the lives of concrete dams are identified and illustrated by examples from recorded experiences.A number of major concrete dam failures,including that of the St.Francis dam,California,U.S.A.,in 1928,have led to significant developments in rock mechanics and rock engineering knowledge and techniques,as well as in dam design and review processes.More recent advances include a range of analytical,numerical modelling,probabilistic,reliability,failure mode and risk assessment approaches.

Risk Assessment at the Design Phase of Construction Projects in Ghana

The study was carried out exclusively in Ghana to explore the approaches employed by consultants in risk assessment at the design phase of projects in Ghana. One hundred and fourteen (114) consultants were selected out of a population of one hundred and eighty six (186) from three main professional associations in Ghana made up of the Ghana Institute of Architects, Ghana Institution of Engineers and the Ghana Institution of Surveyors (Quantity Surveying Division) practicing in Ghana for the study. Both primary and secondary data were collected. A descriptive survey was also used to observe and describe the presence, frequency or absence of characteristics of a phenomenon as it naturally occurred, in order to gain additional information. A questionnaire was also designed to collect data from the architects, engineers and quantity surveyors. The data was analyzed using Statistical Package for the Social Scientists (SPSS) 17.0. Descriptive and inferential statistics, such as frequency tables, percentages and cross tabulations were used in the data analysis and summaries. Simple tests of associations were undertaken by using Chi square and Cramer’s V statistics to compare relationships between variables. Again, relative importance index was also used to analyze some of the data by computing to deduce their rankings. The relative importance index was used to analyze some of the data by computing to deduce their rankings. The research revealed that majority of consultants had an average knowledge of risk management. Based on the findings it was recommended that consultants undergo advanced training in risk assessment. It was therefore suggested that consultancy firms should develop a set of laid down procedures for consultants to use in risk assessment in order that the use of intuition employed by majority is lessened. The challenges observed in risk assessment and the remedial steps suggested curtailing the detrimental effects of risks would be of wide importance to many developing economies.

Identifying Risk at the Conceptual Product Design Phase: A Web-Based Software Solution and Its Evaluation

This paper introduces a web-based application that enables engineers or designers to identify risks during the conceptual phase of a product design. This software application was developed based on the Risk in Early Design (RED) method developed by Author, Stone, and Tumer. The RED method demonstrates that risks can be identified in the early phase of product design by relating recorded historical failure information to product functions. Based on the concept of RED theory and current industry needs, the goals of a web-based RED application were defined. These goals are the intended benefits or functionalities that the web-based RED application would provide. In addition, a multi-level evaluation framework was adopted to determine how well the application meets the needs of various organizations. As part of the evaluation, a questionnaire was developed and administered to a sample industrial and academic user group. The results of the evaluation indicate that the web-based RED software application meets many of the goals to help an organization in performing product risk analysis.

Simulation and uniform design-based automatic generation of risk scenarios

This paper presents a methodology for automatically generating risk scenarios for dynamic reliability applications in which some dynamic characteristics(e.g.,the order,timing and magnitude of events,the value of relevant process parameters and initial conditions) have a significant influence on the evolution of the system.The main idea of the methodology is:(i) making the system model "express itself" through simulation by having the model driven by an elaborated simulation engine;(ii) exploiting uniform design to pick out a small subset of representative design points from the space of relevant dynamic characteristics;(iii) for each selected design point,employing a depth-first systematic exploration strategy to cover all possible scenario branches at each branch point.A highly dynamic example adapted from the literature(a chemical batch reactor) is studied to test the effectiveness of the proposed methodology.

Towards Development of a Security Risk Assessment Model for Saudi Arabian Business Environment Based on the ISO/IEC 27005 ISRM Standard

Security risk assessment refers to the process of identifying, analyzing, and evaluating potential security risks for an organization. An organization’s assets, personnel, and operations are protected through it as part of a comprehensive security program. Various security assessments models have been published in the literature to protect the Saudi organization’s assets, personnel, and operations. However, these models are redundant and were developed for specific purposes. Hence, the comprehensive security risk assessment model used to safeguard Saudi organizations’ assets, personnel, and operations is still omitted. Using a design science methodology, the objective of this study is to develop a comprehensive security risk assessment model called CSRAM to assess security risks in Saudi Arabian organizations based on the International Organization for Standardization and the International Electrotechnical Commission/Information security risk management (ISO/IEC 27005 ISRM) standard. CSRAM is made up of six stages: threat identification, vulnerability assessment, risk analysis, risk evaluation, risk treatment, and monitoring and review of the risk. The stages have many activities and tasks that need to be accomplished at each stage. Based on the results of the validation of the completeness of the CSRAM, we can say that the CSRAM covers the whole ISO/IEC 27005 ISRM standard, and it is complete.

不确定性视角下灾难防控的社会支付意愿评估研究

灾难政策设计需要权衡政策实施的成本与收益。社会支付意愿常用来评估灾难防控政策收益,其依赖于灾难损失的大小。灾难概率和规模是刻画灾难损失的两个重要变量。因此,本文基于灾难概率与规模提出了一种评估灾难防控的社会支付意愿理论框架。首先分析了灾难概率与期望规模对社会支付意愿的影响。结果发现,随着灾难概率的增大,社会支付意愿增大,但是减少单位灾难概率的社会支付意愿是下降的。随着灾难规模的增大,社会支付意愿也增大,且减少单位灾难规模的社会支付意愿是上升的。这意味着,社会支付意愿对灾难规模更敏感,特别当灾难规模较大时,为减少灾难规模社会愿意支付更多成本。进一步,考虑到灾难规模的厚尾不确定性,研究了灾难规模不确定性对社会支付意愿的影响。结果发现,随着灾难规模不确定性的增大,社会支付意愿也是增大的,但是减少单位灾难规模不确定性的社会支付意愿是下降的。这为灾难政策设计时如何权衡灾难概率与灾难规模提供了重要参考。

Risk Assessment of Aircraft’s Lateral Veer-off the Runway Surface during Landing

This article presents a methodology to determine the risk of aircrafts lateral runway excursion during landing via mathematical risk modeling. In addition, the methodology is demonstrated by means of detailed calculation of the lateral runway excursion risk value during the landing of the aircraft Airbus A310-200, in view of the maximum landing weight and the appropriate range of landing velocities according to the International Civil Aviation Organization specification. Obviously, the calculation demonstrates that the developed math solutions and equations presented herein are powerful tools to evaluate the risk of lateral runway excursion of the majority of aircrafts and for any airport. The method is also applicable to assess the residual level of risk at any specific airport and its deviation compared to the recommended safety level. Consequently, the presented mathematical solutions to determine the risk rate of lateral runway excursion during landing offers airports’ operational and safety management departments a viable tool so that appropriate measurements could be adopted. Finally, it is a methodology not only to assess the risk but also to determine the appropriate runway width.

不确定需求条件下考虑风险公平的危险品运输网络设计问题

危险品运输事故具有低概率、高后果的特征,降低事故风险是危险品运输研究的重点。危险品运输产生风险的同时伴随着风险在空间上的分布不均衡,此前研究关注总风险最小和风险公平的权衡,但较少考虑不确定需求下的运输网络。运输需求波动可能引起风险增加,为了解决不确定需求下考虑风险公平的危险品网络设计问题,构建了危险品多起点-终点(OD)对运输网络设计的双层混合整数规划模型,上层和下层问题分别为监管者选择关闭路段以及承运人选择最优路径,并通过自适应遗传算法和局部搜索算法进行求解。通过实例分析发现,不同需求情景特别是部分OD对中断时产生不同的最优网络设计方案,采用的遗传算法相比局部搜索算法运行时间稍长情况下获得的解更优。

基于风险补偿效应的银行转股型永续债优化设计与定价

效应是衡量金融产品设计成败的重要依据。研究对永续债内蕴的风险补偿效应进行剖析与量化,并以风险补偿效应的控制为依据对转股条款进行优化设计:特别考虑了“部分转股”的情景,即在轻度财务困境时可实施部分转股,弥补了现有条款“一刀切”式的全部转股方式的弊端。进一步,给出了与所设计的转股条款相适宜的各利益方权益价值的结构化定价方法,并构建了可体现各利益方激励相容性的确定转股比例的约束优化模型,以充分体现发行方与投资者之间的“共建共享”特征。数值分析结果表明:适宜的转股条款设计可较好地控制风险补偿效应,既兼顾了永续债投资者的利益,又保护了发行银行股东的权益,且有利于提高发行银行的价值;所设计的转股条款在多种情景下均具有良好的可实施性,进而有望为永续债市场的良性发展提供有益的决策参考。

中国碳排放权交易机制与实践:基于微观企业股权资本成本的视角

碳排放权交易市场作为企业减排增效的重要机制,引发了资本市场投资者对企业碳排放问题的关注,进而可能影响投资者对企业的风险评估与价值判断。手工整理中国各试点碳市场的控排企业名录发现:碳排放权交易机制显著提升了控排企业的权益资本成本,主要机制为投资者碳风险关注,但该市场机制存在明显的效应边界。进一步发现,当碳市场的初始配额实施部分竞价拍卖和非履约主体交易更为活跃,产品市场竞争程度更高和企业所在城市空气污染更为严重,以及企业非财务绩效表现更好时,碳排放权交易机制对企业权益资本成本的提升作用更为明显。研究结论有助于更为全面的评估我国碳市场建设的经济后果,为该低碳环保政策的持续推广提供理论依据与经验参考。

Design Tide Hydrograph with A Given Risk Threshold by A Copula-Based Multivariate Method

This paper describes the development of a T-year design tide hydrograph （DTH）. A core innovation is that the proposed technique uses the design risk threshold and copula-based conditional risk probability to analyze the optimal combination of high waters and low waters of the DTH. A brief description of the method is presented. The in situ semi-diurnal tide data at the coast of Jiangsu Province in China are analyzed. Marginal distributions for high waters and low waters of tides are examined. Furthermore, the joint distributions, condition risk probabilities and risk thresholds of high waters and low waters are presented. Results of the DTH from the proposed method are compared with those from the traditional same-multiple enlarging design approach. It is demonstrated that the proposed method is preferable.

基于正交试验的民用飞机抗爆结构参数敏感性分析

最小风险炸弹位置(LRBL)结构是放置飞机上可疑爆炸物的装置,探究结构尺寸和炸药位置对其抗爆性能的影响程度可为其改进设计提供参考。基于正交试验设计与数值模拟相结合的方法,以LRBL结构各危险部位的最大应变和变形为评价指标,分别运用极差分析法和方差分析法对LRBL结构的罐体壁厚、底盖厚度、连接凸台厚度、剪切销直径和炸药位置5个影响因素开展参数敏感性分析。结果表明:在200 g炸药当量的工况下,各因素对LRBL结构的抗爆性能的影响显著程度从大到小为炸药位置、罐体壁厚、底盖厚度、凸台厚度和剪切销直径;结合评价指标综合分析得到各个因素最优水平下的LRBL结构设计方案。

考虑洪水入侵的地铁站楼梯疏散风险研究

为增强地铁站应对洪涝灾害能力和楼梯设计韧性,基于改进的k-ε模型和洪涝疏散风险评价模型,构建地铁站楼梯上洪水入侵流态数值仿真场景,定量分析坡梯设置、楼梯倾斜度和洪水深度对洪涝疏散风险的影响。研究结果表明:在相同倾斜度(23.2°)和入侵洪水水深(0.3 m)的情况下,相较于楼梯台阶对洪水的阻缓作用,斜坡上洪水流速更快、水深更为平稳,但斜坡具有更高的洪涝疏散风险;洪涝疏散风险与楼梯倾斜度成正相关,疏散风险随着楼梯台阶的降低呈现“前快后缓”特征,斜坡对疏散风险的边际影响更为均匀,而宽大的台阶设置更有利于缓解疏散风险;楼梯上平台入口水深越大,洪涝疏散风险越高;洪水与下平台积水容易产生跳水现象,导致洪涝疏散风险急剧攀升和震荡递减。研究结果可为地铁站科学制定洪涝疏散方案和楼梯设计提供理论指导和管理启示。

油田井控安全风险控制技术刍议

在我国经济的可持续发展中,油井建设是核心基础设施之一。然而鉴于油田的独特性,近些年来,井喷失控事件频繁出现,严重影响了社会的稳定发展和公众的生命财产安全。基于这种情况,要求严格控制油田井控安全风险。在此基础上,首先介绍油田井控安全管理的主要特征,然后从井身结构、地表压力、开发方式与区块、员工素质水平等方面,分析了如今油田井控面临的安全风险,最后从分级安全风险防控、分级监管技术、防卡、防漏、防喷技术、井控风险的不同等级、安全钻井技术等方面,提出了相应的风险控制技术及其策略以供参考。

自然灾害风险监测框架及产品体系设计

自然灾害风险监测是防灾减灾救灾领域的基础性和前沿性工作,为风险评估、灾害预警和综合减灾提供基础数据和研判信息。自然灾害风险监测当前处于理论研究和业务探索阶段,存在业务服务不精准、产品体系不健全、实践难题未凝练、关键技术未突破和监测站网不完备等难题,还不能满足灾害风险早发现、早识别和早防范的现实需求。结合多灾种灾害链基础理论和业务实践,阐明“为何监测、何时监测、怎么监测、监测哪里、监测什么”等业务系统化、体系化发展思路。为全面提升自然灾害风险监测产品决策支撑能力,设计了包括业务体系构建、关键技术突破、标准规范形成、数据库建设、应用平台开发和典型应用推广等在内的总体框架,构建应用场景、产品类型和产品要素一体化的科学精细的业务产品体系。

基于C-FRAM的油气藏型地下储气库设计期关键风险因素辨识方法

油气藏型地下储气库设计工作围绕运营阶段的功能实现与建设阶段的相应改增建任务开展,前期的储气库设计偏差可能会对储气库建设乃至投产运营产生深远的影响。功能共振分析方法(FRAM)主要用于分析扰动在系统中的传播路径。由于储气库设计期需要综合的信息繁多、跨度广泛,为考虑在复杂网络中各功能模块的影响力,首先针对储气库设计期功能的特点提出一种考虑功能模块中心性的系统功能共振分析方法(C-FRAM),然后以重庆相国寺储气库为例开展案例分析,最后提出对设计期储气库的规模部署与下游供应调峰需求、地质实施方案、老井利用等方面的建议。结果表明:引入功能模块系统中心性有助于修正储气库设计期关键风险因素排序。

化工工艺管道设计风险分析与安全对策研究

随着高质量经济发展需求,化工行业基础支柱产业地位越发重要,同时化工行业发展也面临着更加严峻的挑战。化工行业化工设备设计、安装和规范化管理尤为重要,在化工工艺管道、设备设计、布置和安装过程中,需要准确识别化工管道、设备安全设计存在的危险因素,制定规范化的安全事故处理应急机制,提升安全生产事故风险防控水平,保障化工工艺和管道安全运行。本文首先开展化工工艺管道设计整体介绍,分析在工艺管道设计和安装过程中存在的风险,分析存在的风险因素,并根据安全风险因素进行针对性的安全对策研究,尽可能降低化工工艺管道运行风险,保障化工工艺和管道安全运行。相关研究可为化工工艺管道安全设计与运行提供一定的借鉴意义。

基于大数据技术的智慧电厂作业预警系统设计

在全面推进智能电网建设的战略目标,建立高标准的电力能源企业过程中,电厂作业过程的监控和风险预警面临着新的要求。为满足这一要求,文章提出如何利用智能化监控设备和大数据技术,对电厂作业行为进行实时监测,为电厂作业风险预警提供全面的数据支持。在此基础上,文章着眼于大数据技术在智慧电厂作业预警系统中的应用展开研究,以期通过智慧电厂作业预警系统的使用,实现对电厂作业过程的智能监测与评判,从而加强风险防控。

化工工艺安全设计中危险识别和控制研究

随着化学工业的迅速发展,工艺设计中的安全问题愈发受到关注。本文首先解析了化工工艺安全设计的概念和特点,详细讨论了在化工工艺中可能出现的各种风险,包括与化工物料、生产设备、生产流程和工艺过程相关的潜在危险。为了更好地识别和控制这些风险,提出了一系列的策略和方法,涵盖了物料、管道、线路和装置等关键部分,以期为实际的化工工艺设计提供有益的参考。