建筑火灾坍塌危险性的评估

从建筑火灾坍塌事故的特点及危害入手,分析了火灾中影响建筑坍塌时间的因素,阐述了建筑火灾坍塌前兆,得出建筑火灾坍塌危险性评估结论:在无爆炸发生情况下,无先天质量问题的钢筋混凝土建筑,一般在火灾持续5、6个小时内不会发生整体坍塌;我国北方建筑比南方的建筑普遍抗烧塌性相对较强;按防震设计的震区建筑,其火灾抗塌性明显增强;灭火冷却及时的建筑不易坍塌。     

建筑结构抗火设计综述

阐述了建筑火灾的危害性,揭示目前我国结构抗火设计的缺点,提出基于计算的结构抗火设计方法,并指明了结构抗火设计方法有待进一步研究的问题。     

钢结构防火漫谈

随着我国经济的发展和建筑技术的日新月异,钢结构这种建筑结构形式以其重量轻、承载力大、施工简便、布局灵活等特点广泛应用于超高层建筑、体育馆和大型厂房等建筑中.但由于钢结构存在不耐火的致命弱点,发生火灾时极易发生倒塌,造成重大的人员伤亡和财产损失,其防火问题备受人们的关注.……     

火灾引发超高层建筑非连续倒塌模拟研究

为了解超高层建筑发生火灾后变形特征及失稳后的非连续坍塌过程,掌握引起变形和坍塌的原因,将三维颗粒流软件(PFC3D)作为模拟平台,设置核心筒-框架结构的超高层建筑火灾区域,并模拟坍塌过程。在考虑钢筋和混凝土共同作用结果的基础上,提出火灾区域中构件属性设置方法及模拟步骤。分析得到造成建筑结构摆动的3种原因,一是火区位置不同导致上部结构对火区的压力不同,二是火区位置不同导致结构受到的约束不同,三是受热膨胀性使构件产生不同程度变形。结果表明:燃烧温度为500℃,3 h后建筑发生摆动,表现出对火区位置和燃烧时间敏感的特征。1 000℃下1 h内,建筑物首先发生破坏的是梁构件,然后是承重柱。即建筑一旦进入结构破坏阶段,坍塌将是迅速且不可逆的。     

建筑钢结构中钢构件的防火性能与抗火设计研究

首先有针对性地对当前国内外建筑钢结构中钢构件的防火性能与抗火设计研究背景做了较系统分析,接着,通过有限元程序,对当前应用非常广泛的半刚接门式刚架建筑在火灾高温下的受力性能进行了整体结构非线性分析。计算结果表明：随着温度的升高,钢构件节点的刚度不断下降,当节点的刚度下降到不能约束与其连接的梁柱构件时,结构将发生突然坍塌性...     

钢结构工业厂房火灾风险管理探讨

钢结构厂房在工业企业中应用广泛,但由于其耐火能力差,近年来发生了多起钢结构厂房在火灾中倒塌导致多人伤亡的事故。从钢结构建筑防火设计和防火管理的角度出发,分析了影响钢结构厂房抗火灾能力的主要因素,发现变更使用条件是导致钢结构建筑消防能力不足的重要原因。建议钢结构建筑管理方改变管理模式,实施主动地火灾风险管理,并不断提升专业水平以满足特性火灾风险管理的需求。另外,将企业风险管理方法引入火灾风险管理中,提出实施火灾风险管理的流程,并就管理操作中的重点内容进行分析,希望对钢结构火灾风险管理的系统分析和具体实施提供帮助。     

火灾演化、整体火安全和火灾蔓延

本在介绍了自然火灾演化过程及关荷载如何确定后,对建筑整体火安全概念进行了讨论,包括火灾时居民和消防人员的安全性、自然抗火时间、结构火安全设计和财产损失。对结构破坏后的火蔓延计算及标准热荷载的应用也进行了讨论和介绍。     

考虑抗火性的工业厂房火灾后结构可靠性评级

为更全面地反映火灾对工业厂房可靠性的影响,确保火灾后结构安全性评级的准确性,结合我国火灾后工业厂房可靠性评级的特点,加入抗火性这一特殊指标,将耐火等级、火灾裂缝和变形3个因素作为抗火性的评级指标,并确定抗火性等级划分标准。建立基于Vague集相似度量理论的、考虑抗火性的火灾后工业厂房结构可靠性综合评级模型。将模型应用于5个工程实例。结果表明,评级结果与规范评级法的结果一致;与未考虑抗火性的规范评级法相比,量化后的评级指标不仅评级过程清晰,而且能有效避免人为因素导致评级结果出现的误差。     

火灾环境下钢结构力学响应行为研究回溯与前瞻

火灾环境下高温对结构钢材的力学性能具有显著的不利影响.通常钢材在200～400℃的温度下力学性能开始下降,在800℃以上几乎丧失所有的强度.火灾环境下的钢结构力学响应行为是钢结构抗火设计的前提.为了展示火灾环境下钢结构的力学响应研究的清晰脉络,首先综述了火灾环境工况加载、钢结构升温规律的研究文献,然后从钢的耐火性能分析开始,评述了钢结构形式对耐火性能的影响和热作用下的结构变形研究.研究表明:若采用ISO 834标准升温曲线作为热加载方式,钢结构的升温规律和力学响应行为与真实火灾场景下相比差异显著,在标准火下钢的抗火时间更长;钢结构在火灾环境下的热应变随温度升高而增大,最终导致屈曲和过度挠度;当温度超过400℃时,高温蠕变会加速结构的失效;试验和数值模拟方法能很好地预测钢结构在真实火灾环境下的温升规律;较为真实地表征钢结构的不均匀力学响应行为,首先需要加载真实的火灾工况,同时要充分考虑钢结构形式,并耦合运用工程热物理、力学相关工具和方法;钢附着可燃材料燃烧的热反馈及相应的力学响应行为是钢结构抗火研究的新问题,针对该问题需要建立科学的热-力耦合工程定量测试方法.     

旧工业厂房结构安全鉴定方法探讨——以西安某旧工业厂房为例

在对全国典型旧工业厂房改造项目充分调研的基础上,针对不同的建筑结构形式,分别研究超声回弹综合法、平测法、半电池法、扁顶法等方法,对适用于旧工业厂房结构安全的鉴定方法进行探讨,分析鉴定方法针对旧工业厂房的适用性、科学性,对我国旧工业厂房安全改造有重要意义。     

油浸变压器排油注氮装置在500kV变电站的设计与应用

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.     

HAZOP结合What-if方法在某延迟焦化装置除焦中的应用

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。     

潞安矿区煤层渗透率的各向异性特征实验研究

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。     

Nighttime pedestrian fatalities: A comprehensive examination of infrastructure,user, vehicle,and situational factors

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.     

Footedness and Mounting—Short Review and Two Case Studies

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).     

AHP与GA-SVM耦合模型在滑坡预警中的应用*

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。     

Debunking the false dichotomy of leadership idealism and pragmatism: Critical evaluation and support of newer genre leadership theories

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.     

Occupational Safety and Health in Finland

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.     

森林地表火蔓延模拟方法及其计算机实现

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。     

公路隧道火灾逃生疏散研究

以苍岭隧道为背景,首先采用经验计算理论和计算软件building EXODUS相结合的方式,从被困人员的安全疏散时间、高温烟气的影响、隧道横通道的利用率以及人员的疏散行为特性进行了研究。结果表明:中小规模火灾情况下的安全疏散时间控制在8 min之内,高温烟气影响不大,但横通道的利用率不平均,且人员疏散路线相对集中。然后对存在的逃生疏散问题提出针对性建议以及其他相关建议,旨在为更大程度降低事故的严重性和经济财产损失。