多方博弈下起重作业人员有意不安全行为致因分析

为有效制定起重作业人员有意不安全行为防范措施,降低人为事故发生可能性,结合演化博弈理论,探讨不同策略选择下施工企业内部管理方、监管方及作业方的得益变化,建立各方期望效益函数;依据复制动态方程,构建多方演化博弈模型,分析各方策略选择演化趋势及均衡点,剖析作业人员有意不安全行为致因,并分别从各方角度制定作业人员有意不安全行为预防措施。结果表明:作业人员有意不安全行为不仅与自身风险、成本有关,且受管理方、监管方决策影响;管理方增加安全投入,提升作业人员事故损失承担比例;监管方选择合理监管方式严格监管作业行为;作业人员进行行为决策时权衡风险、成本、收益及各方决策,将有效减少作业人员有意不安全行为的发生。     

基于顶板离层监测的锚固巷道稳定性控制

在提出顶板离层概念的基础上 ,对顶板离层与锚固系统的变形协调条件以及离层临界值、失稳临界值及工程估计值的确定进行了分析 ;通过实例 ,说明了离层监测与反馈的应用 ;工程实践表明 ,采用顶板离层监测是锚固巷道稳定性控制的简易技术手段 ,其技术经济效果明显 ,是一种值得推广的实用方法     

Trajectory variability: Road geometry difficulty indicator

The analysis of the variability of vehicle trajectories can reveal important information about how situational constraints influence drivers’ behaviour (e.g., lateral position and/or speed). Variability in the lateral position using a driving simulator was examined. Forty-two participants had to drive on two road environments: a 3 km straight road with a crest vertical curve (CVC) with perceptual treatments and narrowed lane width with subsequent provision of a hard shoulder, by relocation of the road markings. The results showed that, on the one hand the lateral position variability was greater when driving on the test CVC, before meeting oncoming vehicle and on the narrowed lane width; and on the other hand it was limited according to the perceptual treatment used. The lateral position variability would be a difficulty indicator of road geometry which would inform road managers of the presence of a risk zone on their road network.     

Evaluating the speed camera sites selection criteria in the UK

Introduction: Speed cameras have been implemented to improve road safety over recent decades in the UK. Although the safety impacts of the speed camera have been estimated thoroughly, the criteria for selecting camera sites have rarely been studied. This paper evaluates the current speed camera sites selection criteria in the UK based on safety performance. Method: A total of 332 speed cameras and 2,513 control sites with road traffic accident data are observed from 2002 to 2010. Propensity score matching method and empirical Bayes method are employed and compared to estimate the safety effects of speed cameras under different scenarios. Results: First, the main characteristics of speed cameras meeting and not meeting the selection criteria are identified. The results indicate that the proximity to school zones and residential neighborhoods, as well as population density, are the main considerations when selecting speed camera sites. Then the official criteria used for selecting camera sites are evaluated, including site length (a stretch of road that has a fixed speed camera or has had one in the past), previous accident history, and risk value (a numerical scale of the risk level). The results suggest that a site length of 500 m should be used to achieve the optimum safety effects of speed cameras. Furthermore, speed cameras are most effective in reducing crashes when the requirement of minimum number of historical killed and seriously injured collisions (KSIs) is met. In terms of the risk value, it is found that the speed cameras can obtain optimal effectiveness with a risk value greater than or equal to 30, rather than the recommended risk value of 22.     

巷道火灾密闭过程中烟气温度及流动特性研究

为研究巷道火灾密闭过程中烟气的温度变化规律及流动特性,通过缩尺寸实验台和FDS数值模拟软件对12.65,18.97,25.30 kW不同火源功率及25％,50％,75％,100％不同密闭比例条件下的巷道火灾进行模拟实验.结果表明:密闭比例的增加会使火焰倾角减小,当巷道完全密闭后,火焰形状近似垂直,顶板热辐射和温度增加;...     

井下移动热源对巷道局部风流温度影响规律研究

为了研究煤矿井下热源对巷道局部风流温度的影响,通过搭建实验平台以及建立数值模型,采用实验和数值模拟的方法,分析井下固定和移动热源对巷道局部风流温度的影响规律。研究结果表明:对比实验和数值模拟固定热源对巷道局部风流温度的影响,结果显示二者总体温度变化趋势一致性较好,验证了数学模型的正确性;井下热源移动速度不同时,顺风移动速度越大,对巷道局部温度影响越大,且巷道局部温度相对升高;逆风移动速度越大,对巷道局部温度影响越小,且巷道局部温度相对降低。     

矿岩接触带巷道顶板沉降变形相似模拟试验研究

为分析矿岩接触带巷道顶板沉降变形对巷道稳定性的影响,以大冶铁矿尖林山矿区接触带巷道为研究对象,基于相似原理,构建了矿岩接触带巷道物理相似模拟试验模型,设计了沿巷道走向与矿岩接触面对称布置的应变位移计监测方案,分析了接触带巷道顶板沉降变形规律。研究结果表明:接触带巷道顶板两侧岩体沉降变形量和变形速率存在差异,接触带巷道大理岩侧顶板沉降量和沉降速率大于铁矿侧;邻近巷道开挖扰动对已开挖巷道顶板变形破坏有较大影响,增大了接触带巷道两侧岩体的沉降变形程度。结合大冶铁矿矿岩接触带巷道顶板沉降量监测数据,从顶板沉降量、沉降速率2个方面对比分析了相似模拟试验和现场监测试验结果,表明矿岩接触带巷道顶板沉降变形规律具有一致性。     

软岩隧道自旋锚管抗拔力的计算理论

在软岩隧道支护中,大多数情况下需要向上钻孔打锚杆,目前应用较多的中空注浆锚杆和砂浆锚杆在向上打锚杆的情况下,均存在注浆不饱满及不能形成快速初锚力的问题,影响支护效果和工程安全。自旋注浆锚管能比较好的解决上述工程中存在的技术缺陷。在软岩隧道支护中,自旋注浆锚管的抗拔力是至关重要的技术参数,关系到锚固体系的安全。本文根据自旋注浆锚管的结构特点和作用机理,对其抗拔力的计算理论进行了探讨,对实际支护工程有一定的参考作用。     

Exposure factors of Victoria's active motorcycle fleet related to serious injury crash risk

Objective: The purpose of this study was to describe the nature and extent of current powered 2-wheeler (PTW) risk exposures in order to support future efforts to improve safety for this mode of transport.

Methods: A cross-sectional analysis of the control arm of a population-based case-control study was conducted. The control sample was selected from 204 sites on public roads within 150 km of the city of Melbourne that were locations of recent serious injury motorcycle crashes. Traffic observations and measurements at each site were sampled for a mean of 2 h on the same type of day (weekday, Saturday, or Sunday) and within 1 h of the crash time. Photographs of passing riders during this observation period recorded data relating to characteristics of PTWs, age of riders, travel speed of PTWs and all vehicles, time gaps between vehicles, visibility, and protective clothing use.

Results: Motorcycles and scooters represented 0.6% of all traffic (compared with 4% of all vehicle registrations). Riders were significantly more likely to have larger time gaps in front and behind when compared to other vehicles. The average travel speed of motorcycles was not significantly different than the traffic, but a significantly greater proportion were exceeding the speed limit when compared to other vehicles (6 vs. 3%, respectively). The age of registered owners of passing motorcycles was 42 years. Over half of riders were wearing dark clothing with no fluorescent or reflective surfaces. One third of motorcyclists had maximum coverage of motorcycle-specific protective clothing.

Conclusions: A very low prevalence of motorcyclists combined with relatively higher rates of larger time gaps to other vehicles around motorcycles may help explain their overrepresentation in injury crashes where another vehicle fails to give way. An increased risk of injury in the event of a crash exists for a small but greater proportion of motorcyclists (compared to other vehicle types) who were exceeding the speed limit. An apparent shift toward older age of the active rider population may be reducing injury crash risk relative to exposure time. There is significant scope to improve the physical conspicuity of motorcyclists and the frequency of motorcycle specific protective clothing use. These results can be used to inform policy development and monitor progress of current and future road safety initiatives.     

锚杆支护巷道安全监测技术

锚杆支护巷道顶板冒落具有突发性和冒落面积大的特点 ,安全监测非常必要。笔者介绍了国内近年来最新研制的CM— 2 0 0型测力锚杆、GYS— 30 0型锚杆 (索 )测力计、LBY— 3型顶板离层指示仪、ZW— 4型遥测多点位移计等监测仪器 ;提出锚杆支护巷道动态信息施工方法 :监测施工、监测信息反馈、检验和修正设计 ,循环往复 ,以达到最佳施工效果。     

基于模糊规则和BFS算法的行人疏散模型研究*

为建立更加真实的行人疏散模型,基于模糊规则和广度优先搜索（BFS）算法,利用元胞自动机,提出1种优化的行人疏散模型。引入动态模糊速度规则,建立移动速度与周边环境的模糊对应关系,从而模拟行人在不同环境下的运动速度;通过设定危险度规则,使用基于双端队列的BFS算法快速计算每个格子距离安全出口的“静态危险度”,并与出口处人群密度的“动态危险度”耦合,使元胞自发地向“总危险度”更低的方向移动;结合动态速度规则建立1种基于排队理论的出口疏散机制。结果表明:所建模型能够再现行人流自组织现象,真实地反应行人不同的移动方式以及疏散的具体过程;模型考虑了出口排队疏散机制对疏散时间的影响,使疏散效率得到提高,为行人疏散模型的建立以及公共场所的设施布局等应急疏散预案提供有效参考。     

不同因素对巷道支架与顶板接触刚度影响分析

针对超前支架和顶板的接触刚度的影响因素进行仿真分析和实验研究。利用分形理论构造粗糙顶板轮廓模型,根 据不同的粗糙度对应的分形维数D和特征尺度G,在MATLAB中生产不同的粗糙度曲面,并由SolidWorks三维建模软件生产 实体,导入ANSYS软件中进行接触刚度分析。通过仿真和实验研究在不同粗糙度顶板、不同弹性模量的顶板岩层以及不 同形式顶梁的情况下的接触刚度变化。定性地分析了不同影响因素下的接触刚度变化情况,为研究超前支架和巷道顶板 耦合动力学特性提供了依据。     

浮顶油罐密封圈油气分布数值模拟

浮顶油罐一二次密封空间内的油气在雷击作用下可导致起火事故。为研究浮顶油罐一二次密封空间内的油气浓度影响因素,利用CFD方法进行了数值模拟,并建立了浮顶油罐实验模型,检测一二次密封空间内不同位置处的油气体积分数,两者表征的油气浓度情况较吻合;借助该模拟方法进一步分析温度、风速和二次密封泄漏面积对浮顶油罐一二次密封空间内的油气浓度的影响,研究结果表明:①二次密封泄漏面积增加,密封空间内的油气浓度降低。②温度上升,一二次密封空间的油气浓度升高;当风速较高时,温度对油气浓度变化趋势的影响也更大。③风速增加时,空间内的油气分布差异变大,油气浓度最大值变大。     

煤巷顶板沉积岩体钻进动力响应特性试验研究

为了探究煤巷顶板锚固孔钻进动力响应指标（钻速和转速）与顶板岩石物理特性（普氏系数）间的关系,采用实验室及数值试验研究方法对煤巷顶板沉积岩体进行模拟钻进。结果表明,锚固孔的钻进动力响应指标整体上均随顶板岩石普氏系数的增加而减小,大致呈负指数关系。实验室试验数据拟合曲线与数值模拟分析所得结果较为相似,但也存在一定的差别。据此可实现对顶板岩层的初步判别,对煤巷顶板锚杆支护参数的优化和冒顶事故的预防有重要的指导意义;为实验室研究岩石的钻进试验提供了一种可行的方法,也为岩石可钻性与顶板岩层探测仪器的深入研究提供了一定的参考价值。     

综掘巷道超前支护装备双组支撑支护特性实验研究

为提高综掘巷道的掘进效率、改善支护工艺,设计一种用于综掘巷道迎头顶板支护的迈步式超前支护装备。通过对装备工作原理的分析,建立其三维模型。为检验装备的支护效果,设计了支护特性实验方案,构建实验平台,基于实验平台进行了双组支撑状态下的支护实验。实验结果表明:顶板上离固支边越远处动态位移变形量越大,接触力波动也越大; 在双组支撑状态下,顶板变形量最大达到9 mm,接触力最大幅值达到5.84 kN,位置均为顶板纵向中线位置处,在被支护后,该位置最迟趋于稳定; 在双组支撑状态下,顶板变形及接触力经历2~3 s波动后都将趋于平稳; 超前支护装备对顶板的稳定性能起到良好的控制作用,能提高顶板的安全性,为后续产品研发及工业实验提供依据。     

Understanding crashes involving roadway objects with SHRP 2 naturalistic driving study data

Introduction: Crashes involving roadway objects and animals can cause severe injuries and property damages and are a major concern for the traveling public, state transportation agencies, and the automotive industry. This project involved an in-depth investigation of such crashes based on the second Strategic Highway Research Program (SHRP 2) Naturalistic Driving Study (NDS) data including detailed information and videos about 2,689 events. Methods: The research team conducted a variety of logistic regression analyses, complemented by Support Vector Machine (SVM) analyses and detailed case studies. Results: The logistic regression results indicated that driver behavior/errors, involvement of secondary tasks, roadway characteristics, lighting condition, and pavement surface condition are among the factors that contributed significantly to the occurrence and/or increased severity outcomes of crashes involving roadway objects and animals. Among these factors, improper turning movements (odds ratio = 88), avoiding animal or other vehicle (odds ratio = 38), and reaching/moving object in vehicle (odds ratio = 29) particularly increased the odds of crash occurrence. Factors such as open country roadways, sign/signal violation, unfamiliar with roadway, fatigue/drowsiness, and speeding significantly increased the severity outcomes when such crashes occurred. The sensitivity analysis of the three SVM classifiers confirmed that driver behavior/errors, critical speed, struck object type, and reaction time were major factors affecting the occurrence and severity outcomes of events involving roadway objects and animals. Practical Applications: The study provides insights on risk factors influencing safety events involving roadway objects, including their occurrence and the severity outcomes. The findings allow researchers and traffic engineers to better understand the causes of such crashes and therefore develop more effective roadway- and vehicle- based countermeasures.     

Pedestrian fatality and impact speed squared: Cloglog modeling from French national data

Objective: The present study estimates pedestrians' risk of death according to impact speed when hit by a passenger car in a frontal collision.

Methods: Data were coded for all fatal crashes in France in 2011 and for a random sample of 1/20th of all road injuries for the same year and weighted to take into account police underreporting of mild injury. A cloglog model was used to optimize risk adjustment for high collision speeds. The fit of the model on the data was also improved by using the square of the impact speed, which best matches the energy dissipated in the collision.

Results: Modeling clearly demonstrated that the risk of death was very close to 1 when impact speeds exceeded 80 km/h. For speeds less than 40 km/h, because data representative of all crashes resulting in injury were used, the estimated risk of death was fairly low. However, although the curve seemed deceptively flat below 50 km/h, the risk of death in fact rose 2-fold between 30 and 40 km/h and 6-fold between 30 and 50 km/h. For any given speed, the risk of death was much higher for more elderly subjects, especially those over 75 years of age. These results concern frontal crashes involving a passenger car. Collisions involving trucks are far less frequent, but half result in the pedestrian being run over, incurring greater mortality.

Conclusions: For impact speeds below 60 km/h, the shape of the curve relating probability of death to impact speed was very similar to those reported in recent rigorous studies. For higher impact speeds, the present model allows the curve to rise ever more steeply, giving a much better fit to observed data. The present results confirm that, when a pedestrian is struck by a car, impact speed is a major risk factor, thus providing a supplementary argument for strict speed limits in areas where pedestrians are highly exposed.     

浮顶储罐导电片间隙放电危险性研究

储罐在实际运行中,受浮盘的上下移动、机械应力、老化、油污、金属腐蚀等因素的影响,很难确保导电片与罐壁紧密贴合,容易形成微小间隙,在这种情况下遭受雷击易产生间隙放电,出现打火现象.为了分析导电片与储罐罐壁导电片产生间隙放电的危险性,根据Townsend气体放电理论计算了导电片和储罐罐壁间的击穿电压,采用1.2/50μs冲击电压波开展了导电片间隙放电实验,分析了导电片击穿电压与空气间隙距离的关系.结果证明:当导电片和罐壁贴合不良时,导电片和罐壁之间极易产生火花放电;当空气间隙d=0.1cm时,平均空气击穿电压仅为5280V;随着间隙的增大,空气击穿电压也随之增大;导电片间隙放电实验数据与Townsend气体放电理论值吻合.最后,根据以上结论,针对浮顶储罐导电片间隙放电的危险性,提出了改进措施.     

Driver injury in near- and far-side impacts: Update on the effect of front passenger belt use

Purpose: This is a study that updates earlier research on the influence of a front passenger on the risk for severe driver injury in near-side and far-side impacts. It includes the effects of belt use by the driver and passenger, identifies body regions involved in driver injury, and identifies the sources for severe driver head injury.

Methods: 1997–2015 NASS-CDS data were used to investigate the risk for Maximum Abbreviated Injury Scale (MAIS) 4 + F driver injury in near-side and far-side impacts by front passenger belt use and as a sole occupant in the driver seat. Side impacts were identified with GAD1 = L or R without rollover (rollover ≤ 0). Front-outboard occupants were included without ejection (ejection = 0). Injury severity was defined by MAIS and fatality (F) by TREATMNT = 1 or INJSEV = 4. Weighted data were determined. The risk for MAIS 4 + F was determined using the number of occupants with known injury status MAIS 0 + F. Standard errors were determined.

Results: Overall, belted drivers had greater risks for severe injury in near-side than far-side impacts. As a sole driver, the risk was 0.969 ± 0.212% for near-side and 0.313 ± 0.069% for far-side impacts (P < .005). The driver's risk was 0.933 ± 0.430% with an unbelted passenger and 0.596 ± 0.144% with a belted passenger in near-side impacts. The risk was 2.17 times greater with an unbelted passenger (NS). The driver's risk was 0.782 ± 0.431% with an unbelted passenger and 0.361% ± 0.114% with a belted passenger in far-side impacts. The risk was 1.57 times greater with an unbelted passenger (P < .10). Seat belt use was 66 to 95% effective in preventing MAIS 4 + F injury in the driver. For belted drivers, the head and thorax were the leading body regions for Abbreviated Injury Scale (AIS) 4+ injury. For near-side impacts, the leading sources for AIS 4+ head injury were the left B-pillar, roof, and other vehicle. For far-side impacts, the leading sources were the other occupant, right interior, and roof (8.5%).

Conclusions: Seat belt use by a passenger lowered the risk of severe driver injury in side impacts. The reduction was 54% in near-side impacts and 36% in far-side impacts. Belted drivers experienced mostly head and thoracic AIS 4+ injuries. Head injuries in the belted drivers were from contact with the side interior and the other occupant, even with a belted passenger.     

Effects of Ergorest® Arm Supports on Muscle Strain and Wrist Positions During the Use of the Mouse and Keyboard in Work With Visual Display Units: A Work Site Intervention

The effects of Ergorest^® arm supports on wrist angles and musculoskeletal strain in the neck-shoulder-arm region and electrical activity in the shoulder and arm muscles were studied during typing or the use of the mouse in work with a visual display unit (VDU). Twenty-one women were randomized into 3 groups (1 arm support, 2 arm supports, and control). Measurements were carried out before and after the 6-week intervention. The wrist extension of the mouse hand, the muscle activity of the trapezius muscle, and the subjective discomfort ratings indicated that 2 arm supports were better than 1 in work with a mouse. The Ergorest^® arm support alleviates muscle and joint strain in VDU work when used for both arms.