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1.
厦门疏港通道2号隧道上跨芦澳路隧道,2座隧道之间设4条匝道隧道相连,形成半互通立交关系。半互通立交隧道的运营通风受匝道连通的影响,洞内风流有多处分流、多处汇流,形成复杂的网络通风状态,存在主线与匝道之间、匝道与匝道之间的风流分配不准确等问题;同时匝道两端均连着主线隧道,无通向大气的出口,匝道要从主线隧道内引入经过污染的风流,其供风量将大大增加。经过不同通风方案的比选,确定了“匝道半横向式通风+主洞纵向式通风”的方案,从而达到了简化通风系统、降低通风设备功率、提高通风效果、节约投资及有利于防灾救援的目的。  相似文献   

2.
采用数值模拟的方法,对火源位于合流分岔路段上游时不同的纵向通风烟气控制策略进行了模拟分析,得到最佳的通风控制策略及送风参数。研究结果表明:火灾发生时,若只有主隧道送风,当送风风速为临界风速时,尽管火源上游烟气得到了很好的控制,但下游仍会有部分烟气会流入匝道,影响匝道内的行车安全;若加大主隧道送风风速以消除匝道内的烟气,则所需风速过大,既不经济也不安全;如果采用主隧道和匝道联合送风的送风策略,主隧道以临界风速送风,则匝道以较小的送风风速即可得到较好的烟气控制效果。该通风策略应为最优的烟气控制策略。  相似文献   

3.
复杂地下空间交通体系作为新型地下交通形式,车流量大且存在多个分合流点,气流组织复杂,防灾排烟难度极大。以杭州某复杂地下空间交通体系连接匝道为研究背景,提出匝道通风排烟设计方法,再选取其中二合一式连接匝道结构,采用FLUENT模拟其两种防灾排烟方案的有效性。模拟结果表明:两个连接匝道末端单独设置排烟口的设计方案可有效保证火源下游车辆和火源上游人员的逃生安全;根据分合流流速分配理论模型,在合流处只设置一个排烟口且排烟量提高40 m3/s时,也可达到同样的防灾排烟效果,从土建成本考虑,推荐此方案,为同类型隧道结构提供借鉴。  相似文献   

4.
为提高高烈度地震区隧道抗震性能,以某铁路隧道为研究背景,分析3种抗减震措施下隧道不同监测点隧道拱顶沉降、边墙收敛、衬砌结构PGA及最小安全系数,通过对比分析得到最优抗减震措施。结果表明:相比于工况1,工况2隧道拱顶沉降减小10.54%~81.10%,边墙收敛减小13.92%~78.77%,衬砌结构PGA减小31.42%~72.02%,最小安全系数增加18.04%~66.13%;相比于工况1,工况3结构拱顶沉降减小3.04%~18.02%,边墙收敛减小4.70%~32.00%,PGA增加13.95%~27.48%,最小安全系数增加7.49%~30.99%;工况4即“减震层+SFRC衬砌”刚柔并济法,相比于工况1,隧道拱顶沉降减小18.46%~83.98%,结构边墙收敛减小17.54%~85.47%,PGA减小30.00%~69.98%,最小安全系数增加47.95%~83.56%;4种工况抗减震性能由高到低依次为:工况4>工况2>工况3>工况1。研究结果可为隧道软硬围岩交接段抗震设防提供理论参考。  相似文献   

5.
隧道衬砌渗水已成为影响运营隧道结构强度和稳定的关键因素。为了能在运营隧道的日常管理与维护过程中有效预防运营隧道衬砌渗水的发生,从隧道运营管理与维护的角度,运用事故树分析法较为系统、全面地分析得出了运营隧道衬砌渗水的11个基本原因和8个理论预防方案。通过综合比较分析,提出了“有效泄压”和“及时检测修复裂缝”2个预防运营隧道衬砌渗水的可行方案,并相应地给出了各可行预防方案的具体措施。针对不能从本质上解决隧道衬砌裂缝的情况,指出加强运营隧道衬砌渗水检测与预警技术的研究和应用,是实现有效预防运营隧道衬砌渗水的必要途径。  相似文献   

6.
为研究多匝道城市公路隧道内火灾场景下的应急疏散、救援准则以及具体方案,以长沙某城市公路隧道为背景,首先通过对该隧道内的火灾产生机理、特性等主要因素进行研究,确定通道内不同事故类型下的火灾规模;再通过专业的CFD数值计算模型研究不同火灾规模下隧道内的烟雾分布特性及规律;其次依据研究成果制定隧道内各类火灾事故下的通风控制方案;最后制定出隧道内合理烟气控制方案下隧道各个区段人员、社会车辆及救援车辆的疏散救援方案。研究得出多匝道城市公路隧道内小型火灾场景下,烟气能够控制在火灾与火灾下游排烟井范围内;大型火灾场景下利用双排烟井进行排烟时,烟气能够控制在两个排烟井范围内;未受烟气影响的区域内可以正常交通。  相似文献   

7.
南京市城西干道综合改造工程全长6.13千米。该工程在高架爆破残体清完后.于2012年5月全线进入隧道建设施工阶段。工程计划一年半时间.新建4个下穿隧道和一个匝道。  相似文献   

8.
为研究高速公路三岔型互通右转匝道车辆事故的发生机制,以宜宾至叙永高速公路双桥枢纽互通为对象,运用Carsim/trucksim软件建立事故匝道的三维数字模型,模拟小客车和货柜车的运行过程,设置3种不同工况,对车辆在匝道上的动力学特性进行分析。结果表明:行驶速度升高会导致匝道路段的车辆横向偏离增大,发生侧滑或侧翻的几率增加;充分制动距离是保证车辆安全通过匝道受限路段的重要因素,货车需要更长的制动距离;道路视觉环境是影响驾驶人速度选择行为的重要因素,匝道路段与高速公路主线行驶环境的高度近似,导致驾驶人选择较高的速度进入匝道,部分车辆在小半径弯道之前无法将速度降低至安全速度,进而发生事故。本文运用行车动力学仿真和驾驶人视觉手段,在驾驶行为层面分析事故的形成机制,进而提出安全提升措施,可为匝道线形设计和交通运行管理提供科学依据。  相似文献   

9.
为保障城市长隧道交通安全,提高运行效率,分析含多出口匝道的城市长隧道视觉环境特征,结合视错觉机制与色彩心理学原理构建空间导向视觉参照系;基于E-prime软件开展驾驶员心理物理学感知试验,研究该视觉参照系对城市长隧道驾驶安全的改善效果以及最优设计形式。结果表明:蓝、绿信息环境下驾驶员行车舒适度最高,黄色信息警示性强且不会造成剧烈刺激,有利于提高驾驶员注意力;该视觉参照系能够缩短驾驶员对导向信息的视认时间,增加视认距离;韵律图案向隧道进出口适度倾斜以诱导驾驶员产生坡度错觉,当倾斜75°时,诱导驾驶员在坡道主动控速的效果最佳。  相似文献   

10.
地铁在运营中存在诸多风险,特别是外爆炸带来的危害尤为突出。为避免由此产生的风险,需对地铁隧道在外部侧爆炸瞬时强荷载作用下隧道衬砌结构损伤效应进行研究,进而对隧道衬砌结构的损伤程度作出判断。以西安地铁6号线工程为依托,利用ANSYS/LS-DYNA软件建立有限元模型,分析外爆炸荷载作用下应力波的传播规律;选取地面侧爆角度和隧道埋置深度2个因素建立分析工况,研究了外爆炸荷载下隧道衬砌结构的受力状态规律,隧道埋深15,18 m相较埋深12 m衰减了20,125个微应变;同时直观地对隧道衬砌结构的损伤程度进行分析。开展该项研究为地铁隧道结构抗爆防护设计提供了理论依据,具有较高的技术、经济和社会效率。  相似文献   

11.
在分析500kV变电站主变压器消防系统的现状,比较3类消防系统优缺点的基础上,详细论述了主变排油注氮装置的结构组成、工作原理、参数计算、控制系统设计以及需要注意的事项等,为下一步排油注氮装置的推广应用打下基础.  相似文献   

12.
为克服传统危险与可操作性(HAZOP)定性分析方法在复杂操作、间歇作业等过程中使用的局限性,提出在传统HAZOP定性分析方法的基础上结合What-if(故障假设)方法,对人的不安全行为和操作规程不完备所导致的风险后果分析作出补充。详细说明其技术原理、工作流程等使用细节,系统阐述该方法与传统HAZOP定性分析方法的区别,并在某延迟焦化装置的除焦操作的风险分析中应用。经分析,识别出在“给水-泡焦”节点,有“操作规程错误”场景2项,“操作规程不具体”场景1项,不存在“操作人员未按操作规程执行”场景。研究结果表明:本文方法有效且具有较好效果,可以广泛应用于操作规程/作业指导书审查、作业过程隐患排查等方面,帮助企业开展操作层面的风险识别与管理,提升企业的生产安全水平。  相似文献   

13.
Introduction: Pedestrian fatalities in the United States increased 45.5% between 2009 and 2017. More than 85% of those additional pedestrian fatalities occurred at night. Method: We examine Fatality Analysis Reporting System (FARS) data for fatal pedestrian crashes that occurred in the dark between 2002 and 2017. Within-variable and before/after examinations of crashes in terms of infrastructure, user, vehicle, and situational characteristics are performed with one-way analysis of variance (ANOVA) and two-sample t-tests. We model changes in crash characteristic proportions between 2002–2009 and 2010–2017 using linear regressions and test for autocorrelation with Breusch-Godfrey tests. Results: The increase in fatal nighttime pedestrian crashes is most strongly correlated with infrastructure factors: non-intersection unmarked locations (saw 80.8% of additional fatalities); 40–45 mph roads (54.6%); five-lane roads (40.7%); urban (99.7%); and arterials (81.1%). In addition, SUVs were involved in 39.7% of additional fatalities, overrepresenting their share of the fleet. Increased pedestrian alcohol and drug involvement warrant further investigation. The age of pedestrians killed increased more (18.1%) than the national average (3.2%). Conclusions: By identifying factors related to the increase in nighttime pedestrian fatalities, this work constitutes a vital first step in making our streets safer for pedestrians. Practical Applications: More research is needed to understand the efficacy of different solutions, but this paper provides guidance for such future research. Engineering solutions such as road diets or traffic calming may be used to improve identified infrastructure issues by reducing vehicle speeds and road widths. Rethinking vehicle design, especially high front profiles, may improve vehicle issues. However, the problems giving rise to these pedestrian fatalities are likely a result of not only engineering issues but also interrelated social and political factors. Solutions may be correspondingly comprehensive, employing non-linear, systems-based approaches such as Safe Systems.  相似文献   

14.
森林地表火蔓延模拟方法及其计算机实现   总被引:6,自引:1,他引:5  
杜飞  候遵泽  刘家琦 《火灾科学》2001,10(4):204-208
进行了森林火蔓延的研究,对传统的经验公式和模型进行改进,明显发现改进的模型有更好的结果,用计算机巧妙准确地实现了模拟模型,在风力不是特别大,地形变化不是特别剧烈时,该模型有较高精度;并结合火蔓延的主要因素(气象因子、气候、地形等),进行系统分析,写出算地,编制实现地表火蔓延的预测预报计算机系统软件。这对于有效的组织扑救、减少火灾损失、计算森林火灾的损失评估有重要意义。  相似文献   

15.
为了研究原位煤体渗透性的各向异性特征,以山西潞安常村矿3号煤层圆柱试样为对象,利用TCQT-Ⅲ型低渗煤层气相驱替增产试验装置,对煤样进行加载,并以氮气注入压力2.0 MPa的条件下,分析垂直层理和平行层理2个方向的煤体变形和渗透率变化特征。实验结果表明:煤样在加载过程中,平行和垂直层理煤样渗透率均随着有效应力的增大而减小,平行层理方向的渗透率始终大于垂直层理方向,应力加载初期渗透率急剧下降,最后逐渐趋于平缓;径向应变的增加量与渗透率呈正相关性,且平行层理相关性大于垂直层理;沿平行层理方向的裂隙度大于沿垂直层理方向,沿垂直层理方向的应变量大于沿平行层理方向;应变增加量均随有效应力的增加而逐渐减小。研究结果可为煤层井网布置及优化提供参考。  相似文献   

16.
Footedness is a personal quality like handedness. Footedness may be associated with moving ability during mounting, dismounting, and jumping movements. Occupational accidents have occurred during movement at different working levels, during the use of access and exit systems, and during the mounting of vehicles. Aging can also affect accident risk and body laterality. For example, falling accidents on stairs are common among the elderly. One reason for accidents may be that the structure of the access system or stair system is unsuitable for individual moving patterns depending partly on body laterality. Footedness and the way the feet are used may be contradictory to the demands of the moving situation, especially during uncommon or rapid situations. This contradiction may trigger disturbance during moving. The aims of this pilot study were (a) to review the literature briefly and (b) to describe the use of the dominant and nondominant foot by farmers and the elderly when mounting a tractor and stairs, respectively. The study also gives ideas for future studies based on both (a) and (b).  相似文献   

17.
为了减少滑坡造成的损失,提高滑坡预测的准确性,通过搭建灾害模拟平台获得滑坡的实验数据,在获得多组模拟实验数据后,分析各变量的特性。首先,通过层次分析(Analytic Hierarchy Process,AHP)算法,对滑坡进行危险度划分;然后,通过支持向量机(Support Vector Machine,SVM)建立模型,遗传算法(Genetic Algorithm,GA)再优化SVM参数,提出1种层次分析法与GA-SVM相耦合的模型。研究结果表明:AHP方法划分后的数据,通过GA与SVM结合建立的模型精度较好,实验预测结果与实际结果较为吻合,与单一SVM相比,精度更高,结果更好,更加适用于多变量的复杂非线性滑坡预警。  相似文献   

18.
一起有机过氧化物爆炸事故的调查和分析   总被引:2,自引:0,他引:2  
阐述一起重大爆炸伤亡事故的现场调查和原因分析,介绍如何通过人证物证材料,用鱼刺图法找出可能引起事故的诸原因,逐项加以分析,将与人证或物证材料相矛盾的原因子以排除,最后剩下无法排除亦即能与人证物证相符的那个原因,就是事故的真正原因。笔者是这起事故调查专家组组长,取证和数据可靠。  相似文献   

19.
Leadership theories have shifted over the last few decades from a focus on managerial functions and economic leader–follower exchanges toward greater focus on the interpersonal dynamics occurring within the leadership process. Theories such as transformational, ethical, authentic, and other “newer genre” theories were created to address neglected topics such as leader vision and inspirational messages, transparency, emotional effects, morality, individualized attention, and intellectual stimulation. Critiques of these theories, however, have been raised. In this paper, we address five of those critiques and argue for the validity and practical effectiveness of the new genre theories. Further, we describe how newer genre leadership research should be viewed as a performative epistemology, entailing a process of co‐creation involving scholars and practitioners. Finally, from this view, we provide general ideas for leader development. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

20.
Occupational Safety and Health in Finland   总被引:1,自引:0,他引:1  
In Finland, occupational safety is the responsibility of the employer, while the occupational safety and health laws are enforced by the Labour Inspection Service, an organization of the state. The Labour Inspection is divided in 11 administrative districts, and it employs 360 professionals. They are mandated to carry out site visits without prearranged appointments to inspect safe work situations, working hours, construction safety, or any aspect of accident risks. The inspectors are also mandated to verify the existence of sufficient occupational health services as prescribed by the Occupational Health Services Act for all employees. The occupational health services are typically provided by enterprise-owned medical departments, by mutually owned health care centers, by private practitioners, or by municipal health care centers. The latter are required by law to provide all services as prescribed by the legislation to anyone who comes to the facility. This situation is prevalent in the countryside, where there are very few private caregiving centers. Declaring occupational accidents and disease cases is mandatory, and the Inspection districts examine all accidents to establish causes and consequences, and to initiate prosecution in case of criminal negligence. Labour Inspection Districts are also notified of the new occupational disease cases as they are declared to insurance companies. Insurance for occupational disease, accidents, and death is an obligation of the employer, although they can choose the insurance company. The medical confidentiality between the workers and their occupational health care providers is very strict. Official statistics are maintained by the state Statistics Finland organization, and they may be used, for example, for research purposes by scientific institutes like the Finnish Institute of Occupational Health. Construction industry accounts for 25% of all fatal accidents (120 cases per 1 million working hours), followed by mechanical, wood, metal, machinery, and pulp and paper industry (10% each of fatal accidents) with rates ranging from 100–160 cases per 1 million working hours. There are some 5,000 occupational disease cases per year (rate 22/10,000 employed). The major disease categories include repetitive strain injuries (1,300 cases), respiratory allergies (600 cases), occupational skin diseases (1,000 cases), and 900 cases of noise-caused hearing loss. In 1998, 589 cases of asbestos-related diseases were reported.  相似文献   

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