Risk evaluation of rock burst through theory of static and dynamic stresses superposition

Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst risk. Theoretical basis of this method is the stress criterion incurring rock burst and rock burst risk is evaluated according to the closeness degree of the total stress(due to the superposition of static stress in the coal and dynamic stress induced by tremors) with the critical stress. In addition, risk evaluation criterion of rock burst was established by defining the "Satisfaction Degree" of static stress. Furthermore,the method was used to pre-evaluate rock burst risk degree and prejudge endangered area of an insular longwall face in Nanshan Coal Mine in China. Results show that rock burst risk is moderate at advance extent of 97 m, strong at advance extent of 97-131 m,and extremely strong(i.e. inevitable to occur) when advance extent exceeds 131 m(mining is prohibited in this case). The section of two gateways whose floor abuts 15-3 coal seam is a susceptible area prone to rock burst. Evaluation results were further compared with rock bursts and tremors detected by microseismic monitoring. Comparison results indicate that evaluation results are consistent with microseismic monitoring, which proves the method's feasibility.

Landslide Hazard and Risk Assessment on the Northern Slope of Mt. Changbai, China

Landslide hazard and risk assessment on the northern slope of Mt. Changbai, a well-known tourist attraction near the North Korean-Chinese border, are assessed. This study is divided into two parts, namely, landslide hazard zonation and risk assessment. The 1992 Anbalagan and Singh method of landslide hazard zonation （LHZ） was modified and used in this area. In this way, an Associative Analysis Method was used in representative areas to get a measure for controlling factors （slope gradient, relative relief, vegetation, geology, discontinuity development, weak layer thickness and ground water）. For the membership degree of factor to slope failure, the middle range of limited values was used to calculate LHZ. Based on an estimation of the potential damage from slope failure, a reasonable risk assessment map was obtained using the relationship of potential damage and probable hazard to aid future planning and prediction and to avert loss of life.

A quantitative model for danger degree evaluation of staged operation of earth dam reservoir in flood season and its application

Based on the natural disaster risk evaluation mode, a quantitative danger degree evaluation model was developed to evaluate the danger degree of earth dam reservoir staged operation in the flood season. A formula for the overtopping risk rate of the earth dam reservoir staged operation was established, with consideration of the joint effect of flood and wind waves in the flood sub-seasons with the Monte Carlo method, and the integrated overtopping risk rate for the whole flood season was obtained via the total probability approach. A composite normalized function was used to transform the dam overtopping risk rate into the danger degree, on a scale of 0-1. Danger degree gradating criteria were divided by four significant characteristic values of the dam overtopping rate, and corresponding guidelines for danger evaluation are explained in detail in this paper. Examples indicated that the dam overtopping danger degree of the Chengbihe Reservoir in China was 0.33-0.57, within the range of moderate danger level, and the flood-limiting water level （FLWL） can be adjusted to 185.00 m for the early and main flood seasons, and 185.00-187.50 m for the late flood season. The proposed quantitative model offers a theoretical basis for determination of the value of the danger degree of an earth dam reservoir under normal operation as well as the optimal scheduling scheme for the reservoir in each stage of the flood season.

Drought risk assessment in China:Evaluation framework and influencing factors

Global warming and rapid economic development have led to increased levels of disaster risk in China.Previous attempts at assessing drought risk were highly subjective in terms of assessment methods and selection of the assessment indicators and which resulted in appreciable uncertainty in the results of these risk assessments.Based on the assumption that areas with historically high drought losses are more likely to suffer future high drought losses,we develop a new drought risk assessment model that includes historical drought loss data.With this model,we map the regional differentiation of Chinese drought risk.Regions with high(extreme high)drought risk account for 4.3%of China’s area.Five significant high-risk areas have been identified:Northeast China,North China,the east part of Northwest China,the east part of Southwest China and a small part in the west of Northwest China.Areas with high and extreme high drought risk are dominant in the Heilongjiang Province,accounting for 32%of the total area,followed by the Ningxia Hui Autonomous Region,with 26%of total area.The contribution of each influencing factor has been quantified,which indicates that high-exposure and high-vulnerability account for the high-risk of drought.We recommend that measures like strengthening the protection of cultivated land and reducing dependence on the primary industry should be taken to mitigate to drought-induced losses.

Health evaluation method for degrading systems subject to dependent competing risks

This paper proposes a health evaluation method for degrading systems subject to competing risks of dependent soft and hard failures. To characterize the time-varying degradation rate, the degradation process is determined by a non-stationary Gamma process and the soft failure is encountered when it exceeds a predefined critical level. For the hard failure, a Cox’s proportional hazard model is applied to describe the hazard rate of the time to system failure. The dependent relationship is modeled by incorporating the degradation process as a time-varying covariate into the Cox’s proportional hazard model. To facilitate the health characteristics evaluation, a discretization technique is applied both to the degradation process and the monitoring time.All health characteristics can be obtained in the explicit form using the transition probability matrix, which is computationally attractive for practical applications. Finally, a numerical analysis is carried out to show the effectiveness and the performance of the proposed health evaluation method.

Development and Application of Lightning Protection Technologies in Power Grids of China

In recent years,along with the rapid expansion of power grids,the increasing complication of grid structures,and the development of smart grids and energy technologies,the lightning protection of power grids becomes increasingly prominent.Power grids of China have acquired significant achievements on lightning protection technologies,which are reviewed in this paper.A technical route of lightning protection is introduced in detail; it allows us to find problems through detection and measurement of lightning,to analyze problems through evaluation and simulation of lightning,to solve problems through lightning protection measures,and to prevent problems through hazard risk warning of lightning.Following the route,the technical breakthroughs of these four aspects in China are presented,including the chinese lightning detection network(CLDN),natural lightning observations,lightning faults detection at transmission lines,lightning current measurements,progresses in lightning distribution maps,lightning fault replays,lightning hazard risk evaluations,and lightning simulated experiments,as well as novel lightning protection measures.The practical devices and systems corresponding to the technologies mentioned above are also introduced and discussed.Due to the progress of lightning protection technologies in recent years,despite the rapidly growing length of transmission lines in China,the lightning accident rate is controlled at a certain level.

基于无人机倾斜摄影测量三维建模的区域黄土滑坡识别及特征分析

【研究目的】黄土滑坡是黄土地区人居与城镇建设安全的重大隐患。滑坡识别是滑坡灾害及其他研究工作的基础,因此基于无人机倾斜摄影测量三维建模从不同维度、不同视角直观快速地识别黄土滑坡并进行特征参数提取,能够为黄土滑坡风险识别及风险管理精细化研究提供技术支撑。【研究方法】以宁夏回族自治区固原市彭阳县红河镇西南部的黑牛沟村为研究区,采用无人机倾斜摄影测量数据获取、三维建模、现场验证结合地统计学分析,开展了区域黄土滑坡识别及其特征参数提取和分析。【研究结果】基于三维实景模型确定并分析研究区沟谷沿线地貌凹陷区是否存在陡壁及其周界形态,结合色调、纹理和微地貌等标志实现了黄土滑坡识别,共圈定了23个滑坡,结合现场验证移除2个非滑坡点,最终确定了21个滑坡;滑坡密集分布在主沟和支沟沟口,多呈对滑的形式出现在沟谷两侧且具有群发性;大型及特大型滑坡占比达到57.14%,滑坡的滑动方向主要以西南(阳坡)、东南(半阳坡)为主,相对高差集中在80~120 m,滑坡体坡形多呈凹形坡,滑坡体坡度主要集中在20°~30°;滑坡体土地利用类型主要为植被,其次为裸地,也有一部分为农田,道路和河流占比极少。【结论】基于无人机倾斜摄影测量构建的三维实景模型可从多维度、多视角精确快速地识别区域黄土滑坡,并分析其相关特征参数,能够弥补当前二维平面遥感影像存在的不足;还能够为滑坡易发性、危险性、易损性及风险评估等相关研究提供数据支撑。

民航中小机场运行风险管控措施效能评估研究

机场作为关键的交通枢纽和经济引擎,必须实施安全风险管理,以确保其安全运营,为此,提出了危险源管控措施效能评估模型。采集多个机场的危险源数据,对其进行量化分析;利用GloVe将管控措施文本处理成词向量,通过文本卷积神经网络(TextCNN)模型,评估出风险管控措施的效果。通过对比实验,确定危险源管控措施效能评估模型的优劣。结果表明基于TextCNN的效能评估模型的准确率达到74.36%,而基于TextRNN的模型为69.24%。因此,TextCNN更适合用于此类评估任务。本研究为机场管理部门提供了一个新的视角和方法,以更有效地评估和管理各种危险源,从而提升整个机场的安全性能。

基于关联性风险分析的过程管理策略对医疗设备运行效益的影响研究

目的:基于医疗设备关联性风险分析,制定过程性管理策略,提高医疗设备临床运行效益。方法:制定医疗设备管理对策,从主体、质量、环境、制度和诊疗角度进行风险矩阵评估,建立关联性风险综合评估模型。选取2021年4月至2022年3月上海市第八人民医院临床在用的400台医疗设备,采用数表法将其分为对照组和观察组,每组200台,对照组采用个体化风险分析法进行过程性管理,观察组采用关联性风险分析法进行过程性管理。对比分析两组医疗设备的风险等级和运行效益。结果:观察组医学影像诊断及辅助设备、手术治疗设备、生命支持与急救设备、体外循环及血液处理设备和健康监测及康复设备的高危险占比分别为17.39%(4/23)、14.58%(7/48)、12.24%(6/49)、5.55%(1/18)和5.06%(5/62),均低于对照组,其差异有统计学意义(x^(2)=4.132、4.009、6.275、4.833、4.859,P<0.05);观察组医疗设备的成本效益、社会效益、诊疗效益和发展效益评分分别为(91.37±6.15)分、(92.78±3.80)分、(95.25±2.09)分和(90.51±3.82)分,均高于对照组,其差异有统计学意义(t=2.392、3.877、4.841、2.504,P<0.05)。结论:关联性风险分析方法可降低医疗设备安全风险发生概率和危害程度,提高医疗设备临床运行效益,过程管理策略符合医疗设备全生命周期管理的实际需要。

基于改进可拓云模型的装配式建筑施工安全风险评价方法

为保障装配式建筑施工安全,考虑到施工安全指标因素的模糊性与随机性,运用组合赋权-改进可拓云模型对施工安全风险进行评价。首先,从“三度空间”视角下,在物理、社会、信息三个层面构建了评价指标体系;其次,运用改进的层次分析法(AHP)和熵权法(EW)确定主客观权重,基于距离函数确定综合权重,根据云理论和可拓学理论提出一种云熵确定方法,对传统可拓云模型进行改进后构建评价模型;最后,将该模型运用到工程实例中,与其他模型进行对比。结果表明:该施工项目评价等级为很安全,且具有很高的可信度;验证了该模型的可靠性和可行性,为装配式建筑施工安全风险评价提供了一种更加科学、准确的评价方法。

不同构型电动垂直起降飞行器动力系统的安全性评估

安全性评估对电动垂直起降飞行器的架构开发、安全管理、设计验证及商业化有着至关重要的作用,但目前国内少有对电动垂直起降飞行器整机构型、系统设计等相关的研究。本文针对4种不同构型的电动垂直起降飞行器,包括垂起尾推固定翼构型、四轴八桨多旋翼构型、固定翼加倾转旋翼构型以及倾转机翼构型,使用功能危害分析和故障树分析方法对4种不同构型的动力系统进行了分析比较。分析表明:垂起尾推固定翼电动垂直起降飞行器动力架构在本文的特定使用场景中相对可靠性更优。2种分析方法的结合,增加了对功能危害理解的全面性和深度,并识别了减轻动力系统失效风险的多种潜在途径。安全性评估结果可以为电动垂直起降飞行器动力构型选择和产品开发提供依据。

基于偏离度-FCE的袋式除尘系统实时定量风险评价

为保障袋式除尘系统运行安全,预防粉尘燃爆事故发生,提出一种基于偏离度-模糊综合评价(FCE)的袋式除尘系统实时定量风险评价模型。首先,基于工业物联网传感器采集的除尘器进出风口压差、除尘箱温度和锁气卸灰故障信号等指标的监测数据,引入偏离度实现监测指标的风险量化;其次,采用FCE法计算袋式除尘系统的风险状态,结合层次分析法(AHP)和变权理论对评价指标赋权,依据隶属函数和隶属度加权平均原则,量化基于偏离度的袋式除尘系统风险,获得系统风险评价结果;最后,运用某型号袋式除尘系统的监测数据验证模型。结果表明:当袋式除尘系统评价指标的监测值越趋近于报警阈值,且趋近于报警阈值的指标数量越多时,所处风险等级越高,评价结果与其实际运行情况具有相关一致性,验证了模型的有效性。

关中平原与黄土高原过渡带地质灾害危险性耦合评价模型研究——以渭南市富平县为例

富平县地处关中平原与黄土高原交汇地带,地貌复杂多变,单一评价模型难以全面进行该区域危险性评价。该文依据地貌条件,将富平县划分为4个评价区域,选取高程、坡度、坡向、起伏度、距河流距离、距断层距离、地层岩性和坡形8个评价因子,使用了显著性与独立性方法筛选出不同评价区域下最优评价因子。综合逻辑回归法和信息量法,构建了研究区地质灾害易发性评价耦合模型;采用ROC曲线对整体与分区域地质灾害易发性评价结果进行精度对比,得到AUC值分别为0.842和0.893,表明分区域评价结果精度更高。综合地质灾害易发性评价结果与降雨量数据,对研究区进行地质灾害危险性评价,得到极高危险区主要分布于研究区北部与西北部低山丘陵区。

基于LEC法的磷矿矿山作业岗位水患风险评价

在地下矿山建设和生产时期,水患从始至终都是影响正常生产及人员安全的重要因素。为有效评价地下磷矿矿山开采作业中遇到水患风险情况,基于地下磷矿矿山掘进作业活动、工作步骤和场所部位,选取透水作为主要事故类型,并对涉及水患的作业岗位进行识别判定,运用增加修正系数后的作业条件危险性分析法对其进行评价,得出了相对前一个风险评价时期的风险等级,以及涉及水患岗位面临透水事故三个重要参数-事故发生的可能性变化、暴露于危险环境频繁程度和危险性相较于前期变化,然后确定使得风险的等级变化的影响要素,使得各个责任部门、岗位以及管控层级明确自身防控重点,落实安全责任。

基于多维度评价的动车组故障等级划分方法研究

对动车组故障等级进行合理划分,有助于判断不同故障模式对整车和线路运营所造成不良后果的严重程度。基于故障影响范围、影响时间、故障概率3个评价维度,使用层次分析法对动车组不同故障情形进行综合评分,并按照严重程度的大小划分为4个等级。在此基础上,提出了一种结合该种故障等级划分方法的危害度计算模型,通过某型动车组高压牵引系统危害性的计算,分析说明方法的可行性和适用性。

基于系统与场景双重分析的SOTIF方法研究

随着自动驾驶技术的发展,电子电气系统日益复杂,预期功能不足引发的危害逐渐提升。本文基于ISO 21448:2022中SOTIF开发过程,从功能规范与设计出发,识别SOTIF相关的危害并进行风险分析,识别潜在功能不足与触发条件,评估系统影响并提出改进措施,提出一种系统的、有逻辑性的将系统分析方法与场景研究相结合的自动驾驶系统预期功能安全分析方法,并通过该方法在HWA功能上的应用,验证了该方法的可行性。

基于信息量法和GIS技术的竹山县上庸镇滑坡地质灾害危险性评价研究

在对上庸镇地质灾害进行野外实地调查和资料收集的基础上,选定坡度、坡向、地层岩性、地质构造、河流水系为基本因子,选定降雨、人类工程活动为诱发因子,以7个评价因子为基础,建立上庸镇滑坡地质灾害危险性评价指标体系,应用信息量法并通过ArcGIS软件完成上庸镇滑坡地质灾害危险性评价。结果表明:研究区内,极高风险区主要分布在堵河及其支流两侧,此区域地质灾害分布较多,危险性较高,其他区域地质灾害分布则相对较少。

基于AHP-信息量法的怀柔区琉璃庙镇地质灾害危险性评价

该文通过建立坡度、地形起伏度、工程地质岩组、距断层距离、距道路距离和降雨量6个评价指标,利用层次分析法与信息量模型得到各指标权重值及信息量值,对怀柔区琉璃庙镇进行危险性综合评价和分区,划分出低危险区、中危险区、高危险区和极高危险区4类分区。分析结果得出,琉璃庙镇的低危险区面积13.32 km^(2),占全镇总面积的6.46%,琉璃庙镇的中危险区面积73.44 km^(2),占全镇总面积的35.60%,琉璃庙镇的高危险区、极高危险区面积119.54 km^(2),占全镇总面积的57.94%;人类活动密集程度和构造发育程度是影响研究区地质灾害形成的主要因素。评价结果可为怀柔区琉璃庙镇地质灾害的防范与治理提供一定的参考依据。

煤矿采空塌陷区稳定性评价及地质灾害风险评估研究

为进一步探究煤矿采空塌陷区的更多细节特征,从而为治理工作奠定基础,以张双楼大型煤矿采空塌陷区为研究对象,基于层次分析法构建矿山地质环境的因子指标体系,结果显示沉陷区的地表沉陷影响最大的2个因素为开采厚度和顶板岩性,影响相对较小的因素为开采煤层和终采时间,高危险区主要分布在采煤活动频繁的矿区,而中等危险区则位于高风险区域的外围,在地质构造不稳定的区域也可能出现中等危险区,根据评价结果,提出应用“挖深垫浅”的工程模式,并综合应用多种措施,对矿区土地做到更好复垦效果。

城市轨道交通特种设备双重预防机制建设

通过梳理双重预防机制建设的法规要求,结合案例系统提出城市轨道交通特种设备双重预防机制建设方法,利用专家经验法及作业条件危险性分析法(LEC)开展风险评估工作,细化安全风险分级管控评估标准、隐患排查及管理机制,运用信息化系统极大地提升了特种设备双重预防工作效率。双重预防工作在特种设备安全管理中取得良好成效,可为特种设备使用单位特种设备双重预防机制建设提供参考。