基于联系数的地铁隧道施工塌方风险评价研究

目前,地铁隧道施工塌方事故时有发生,为了控制塌方事故的发生,需要对塌方风险进行研究,而风险评价为风险研究的重要方向,本文基于塌方事故的特点,对塌方事故进行危险源辨识,将塌方的致险因子归纳成“人-机-环境系统”,人子系统、机子系统、环境子系统是相互联系、相互影响的,基于集对分析理论构建了子系统及指标之间的联系数,根据各个子系统的不同特征选择不同的评价方法,结合权重及评价分值,最终评价出子系统、系统的风险等级,为建设单位避免地铁隧道施工塌方风险发生提供理论参考。     

基于IAHP的隧道施工塌方风险评价

塌方是隧道施工过程中具有高发性和危害性的事故之一,为防止塌方事故的发生,采用区间层次分析法(IAHP)对隧道施工进行塌方风险因素评价,给隧道施工安全管理工作提供科学依据。通过分析隧道施工塌方风险因素,从工程地质、自然条件、勘察设计、施工技术、管理这5个方面,构建隧道施工塌方风险3级19项指标的评价体系。以新疆地区某隧道工程实例验证该评价模型的可靠性,研究表明影响该隧道施工塌方的主要4个风险因素为:爆破扰动、围岩条件、偏压情况和超前地质预报,评价结果与实际情况相符。     

山岭隧道塌方风险评估模型及系统研究

塌方是隧道施工过程中经常遇到的灾害问题,由于影响其发生的因子众多,且极具复杂性和模糊性,很难对隧道建设施工过程中的塌方问题进行准确地评估。在综合考虑影响隧道塌方风险因素的基础上,归纳整理了影响塌方风险等级的3大类准则层指标,16项指标层指标,构建了山岭隧道塌方风险等级评估模型;采用模糊数学方法确定各指标的隶属函数,并基于层次分析法的原理,编写权重辅助计算程序计算了各指标的权重;为了避免单指标决策的局限性和主观臆断的缺陷,将人工智能专家系统的方法与模糊数学理论结合起来,以面向对象的表示方法构建知识库,开发基于模糊数学的山岭隧道塌方风险评估专家系统。最后利用隧道塌方实例对所提方法的有效性进行验证,评价结果符合实际情况,为隧道塌方风险的评估提供了一种新的可量化分析方法。     

地铁盾构隧道中塌方事故发生的机理与因素

针对近年来地铁工程建设中塌方事故频发的情况,对地铁施工中的塌方进行了分类,并总结了塌方事故的特征,分析了地铁盾构隧道工程塌方事故发生的机理及相关因素,以期指导地铁盾构隧道工程建设。     

城市隧道施工诱发的地面塌陷灾害机制及其控制

针对国内地铁隧道工程经常遇到的塌方事故进行了总结分析,对诱发地铁隧道工程塌方事故的原因进行了深入分析,并提出了改进措施和建议,以降低地铁隧道工程施工风险,提高工程总体效益。     

论地铁盾构法隧道施工中的风险防范

地铁工程施工属于高风险工程,其建设过程的风险管理备受社会各界关注,建立和实行工程风险管理制度已刻不容缓。该文针对地铁盾构隧道施工过程中存在的常见风险,将工程风险管理的基本理论应用到地铁盾构法隧道施工实践中,有效地分析和探究地铁盾构法隧道工程建设中的各项风险识别、风险评价与具体应对措施,从而详细诠释了风险管理在盾构隧道施工中的具体应用。     

强透水砂卵石地层泥水盾构掌子面塌方处理措施研究

强透水砂卵石地层具有透水性强、黏结性差等特点,盾构隧道下穿强透水砂卵石软弱地层易出现掌子面失稳、塌方等问题,对施工效率和安全造成很大影响,掌子面失稳塌方后采取正确处理措施可以有效降低施工风险,避免塌方进一步扩大。结合兰州地铁1号线工程实例,介绍了强透水砂卵石地层盾构施工过程中掌子面塌方处理措施及后续掘进过程中防止进一步塌方的预防措施,经实践验证取得了良好的效果。     

大跨小净距地铁换乘站施工塌方风险分析

塌方是地下工程施工中常见事故,为有效预防施工阶段塌方事故的发生,运用风险分析理论对某大跨小净距地铁换乘站施工阶段塌方风险进行研究,考虑其施工难点,建立施工阶段塌方风险评估指标体系。采用层次分析法（AHP）进行计算分析,得出主要风险因素和塌方风险等级,提出应对措施。     

山岭隧道塌方风险的集对分析方法

如今山岭隧道在我国越来越普遍,已经成为我国交通系统的不可或缺的一部分,因此对隧道塌方的研究具有较大的现实意义。本文在简单介绍了隧道塌方风险研究背景的基础上,相对比较详细的介绍了我国隧道施工的研究现状,最后呆用集对分析方法和层次分析法对我国的山岭隧道塌方风险的评价进行了研究。     

基于非可加测度Shapley值赋权的钻爆法地铁隧道工程施工风险灰色评价

分析了钻爆法地铁隧道施工的工作原理,依据钻爆法施工程序构建了钻爆法地铁隧道工程风险指标体系,研究了各指标之间的非可加测度权重属性,运用Shapley值赋权方法确定各指标权重。在界定地铁隧道工程风险测度的基础上,设计了风险灰色评价的方法,构建了基于Shapley值赋权的钻爆法地铁隧道工程风险灰色评价模型。利用所构建的模型对青岛地铁M1号线长江中路某区段地铁隧道工程进行风险评价,并根据评价结果提出了改进对策,同时验证了该模型的科学性。     

Semi-supervised near-miss fall detection for ironworkers with a wearable inertial measurement unit

Accidental falls (slips, trips, and falls from height) are the leading cause of occupational death and injury in construction. As a proactive accident prevention measure, near miss can provide valuable data about the causes of accidents, but collecting near-miss information is challenging because current data collection systems can largely be affected by retrospective and qualitative decisions of individual workers. In this context, this study aims to develop a method that can automatically detect and document near-miss falls based upon a worker's kinematic data captured from wearable inertial measurement units (WIMUs). A semi-supervised learning algorithm (i.e., one-class support vector machine) was implemented for detecting the near-miss falls in this study. Two experiments were conducted for collecting the near-miss falls of ironworkers, and these data were used to test developed near-miss fall detection approach. This WIMU-based approach will help identify ironworker near-miss falls without disrupting jobsite work and can help prevent fall accidents.     

Factors influencing the risk of falls in the construction industry: a review of the evidence

Falls are a significant public health risk and a leading cause of non‐fatal and fatal injuries among construction workers worldwide. A more comprehensive understanding of casual factors leading to fall incidents is essential to prevent falls in the construction industry. However, an extensive overview of causal factors is missing from the literature. In this paper, 536 articles on factors contributing to the risk of falls were retrieved. One hundred and twenty‐one (121) studies met the criteria for relevance and quality to be coded, and were synthesized to provide an overview. In lieu of the homogeneity needed across studies to conduct a structured meta‐analysis, a literature synthesis method based on macro‐variables was advanced. This method provides a flexible approach to aggregating previous findings and assessing agreement across those studies. Factors commonly associated with falls included working surfaces and platforms, workers' safety behaviours and attitudes, and construction structure and facilities. Significant differences across qualitative and quantitative studies were found in terms of focus, and areas with limited agreement in previous research were identified. The findings contribute to research on the causes of falls in construction, developing engineering controls, informing policy and intervention design to reduce the risk of falls, and improving research synthesis methods.     

An ecological study of physical environmental risk factors for elderly falls in an urban setting of Hong Kong

Elderly fall has become an issue of great public health concern and typically important to the aging population in Hong Kong because it carries a great burden to the individuals and the society. More accurate information about environmental risk factors to falls among the elderly could alleviate if not overcome the situation. Conventional approaches to elderly falls were mainly conducted using statistical methods and clinical tests on falls. This study employs ecological and associative analysis using the geographic information systems (GIS) technology to visualize spatial association of falls and environmental factors. The study identified eleven hot spots of elderly falls with unique environmental characteristics. Amongst various environmental attributes, busy streets and junctions, outdoor markets, and refuse collection points, exhibit a strong spatial relationship with the hot spots. The results have demonstrated that GIS can offer an excellent synergic platform to explore the role of space and pattern in fall occurrences.     

任务驱动式教学法在土力学课程中的实践

土力学是一门重要的土木工程专业基础课程。文章分析了土力学课程教学的现状,指出该课程教学存在的主要问题是知识内容体系落后于人才培养的要求,以及课时少与内容多之间的矛盾;认为将任务驱动式教学法运用于该课程教学中,可以有效提升学生学习的兴趣和课堂效率。文章还介绍了任务驱动式教学法的基本原理,从设计任务、分析布置任务、辅导完成任务、评价任务四个方面阐述了任务驱动法的实施过程。     

Health risk assessment for traffic policemen exposed to polycyclic aromatic hydrocarbons (PAHs) in Tianjin, China

In China, traffic policemen have to stand for several hours a day at the road intersections with high vehicle flows. To assess their exposure to airborne carcinogenic polycyclic aromatic hydrocarbons (PAHs) during their working time, a preliminary study was conducted to measure the personal exposure level to PAHs. And a probabilistic incremental lifetime cancer risk (ILCR) model together with the benzo[a]pyrene (BaP) toxic equivalents (BaP(eq)) method was used to conduct health risk assessment. Personal exposure monitors (PEM) were carried by traffic policemen to collect PM10 samples during their daily work in Tianjin, China. Meanwhile, PM100 samples were collected at the roadsides and on campus of Nankai University as comparison. PAHs species were quantitatively analyzed by GC/MS. Experimental results showed that the concentrations of total PAHs, BaP and BaP(eq) were much higher at the road intersections (867.5, 26.2, 82.4 ng m(-3)), where the traffic policemen stand during their work time, than those at the roadsides (46.6, 1.5, 5.7 ng m(-3)), and on campus (19.5, 0.7, 2.4 ng m(-3)). According to the risk assessment results, the occupational risk falls within the range from 10(-6) to 10(-3). On the basis of sensitivity analysis results, further research should be directed to give better characterization of the yearly concentration distribution of PAHs and the cancer slope factor (CSF) of BaP in order to improve the accuracy of the health risk assessment.     

Development of a tool to monitor static balance of construction workers for proactive fall safety management

The construction industry around the globe is afflicted with an exorbitant rate of fatal and non-fatal falls. To lower the propensity of the falls, researchers and safety experts have recommended to supplement the traditional passive fall safety measures with some active measures (such as early identification of task/environmental hazards and personal risk factors). Unfortunately, at present, there is no readily available onsite tool which could identify workers with poor postural controls. This study aimed to develop a static balance monitoring tool for proactive tracking of construction workers on-site using a wearable inertial measurement unit (WIMU) and a smartphone. To this end, a three-phase project was conducted. Firstly, a validation study was conducted to examine the validity of using WIMUs to detect task/fatigue-induced changes in static balance during a 20-second static balance test. The results of the study revealed that WIMUs could detect the post-task subtle changes in static balance with reference to the findings of a force-plate (considered as industrial standard). Secondly, since there were no existing static balance classification methods, five experts were engaged to establish balance classification thresholds using the fuzzy set theory. Thirdly, a mobile phone application was developed for the managers/foremen for onsite balance monitoring of the construction workers using the 20-second test at different times of the day and establishing their corresponding balance performance profiles. This would assist early identification of fall prone workers, plan mitigation schemes before a fall accident happens and ultimately help reduce falls in the construction industry.     

Falling rock hazard index: a case study from the Marun Dam and power plant, south-western Iran

Rock fall phenomena are a major hazard during construction in mountainous regions. At the Marun Dam site, rock falls occur almost every day on the downstream side. The left flank power plant and access roadways as well as the right flank roadways are susceptible to rock falls from the 100?m high cliffs with slopes of 70??0°. The cause is a combination of the orientation of the bedding planes and joint sets and the active tectonic setting of the area. The paper reports the use of RocFall and Dips software to simulate the conditions in order to define the potential risk of rock falls at the Marun Dam site, which could affect workers as well as structures. In the light of the Falling Rock Hazard Index obtained, preventative and remedial measures are suggested.     

A feasibility study of using smartphone built-in accelerometers to detect fall portents

Fall accidents contribute to nearly half of all fatalities in the construction industry in Taiwan. Detecting fall portents using a smartphone, which many people carry daily, may help reduce fall accidents if the accuracy is acceptable. We designed two experiments with three algorithms to evaluate how well a smartphone can detect both falls and fall portents in a tiling operation scenario. The experiments show that work-related motions barely affected the detection of falls, and the result had a sensitivity and specificity of 100% and 96.1%, respectively. However, for detecting portents, the work-related motions had quite a large impact on the gyroscope-based algorithm, which demonstrated an accuracy rate of only 4.3%, but had only limited impact on the accelerometer-based algorithm, which still show acceptable accuracy rates of 73.5% and 88.5%. We conclude that using a smartphone to detect falls and portents in a construction site is feasible.     

基于古斯塔夫法的大型购物中心火灾风险评估

针对大型购物中心火灾风险评估问题介绍半定量火灾风险评价方法古斯塔夫法,引入无量纲系数弥补建筑物火灾危险度GR和建筑物内人员危险度IR之间没有直接可加性的不足,结合控制风险能力值C计算综合火灾危险度.以北京某购物中心为研究对象,结合消防监督工作实际,运用古斯塔夫法对其火灾危险度进行分析.分析结果表明,该场所的综合火灾危险度为2.128,具有较高的火灾危险性,并且提出了改进建议.     

埋地燃气管道的风险评估技术

阐述了我国进行燃气管道风险评估面临的挑战。用改进的故障树法建立埋地燃气管道阴极保护的风险评估模型,将风险评估模型的结果与现场实测、开挖结果相比较,二者基本一致。该风险评估模型为管道的安全运行及防腐系统的修复工作提供了科学依据。