事故树法在高耸构筑物爆破事故预防中的应用

根据以往工程实践总结得出了高耸构筑物拆除爆破的常见事故类型,通过建立事故树,找出了引起高耸构筑物爆破事故的主要原因,最终提出了预防相应事故发生的措施,并成功应用于湖南冷水江市电厂110 m冷却塔的爆破实践中.     

一起爆破飞石事故的事故树分析

在诸多露天采场爆破事故中,飞石事故占很大的比率,对矿区的安全生产构成了严重威胁.针对一起飞石事故案例,利用系统安全分析中的事故树分析方法,通过最小割集和最小径集的求取,寻找事故发生的原因,提出爆破飞石事故的预防途径和控制措施,从而有针对性地采取安全对策,以减少事故的发生.     

爆破事故的技术安全防范

爆破大大提高了劳动生产率,但如果出现爆破失误,会带来重大危害。必须充分认识爆破造成的事故,做好爆破前的准备工作,进行正确的爆破作业,预防爆破事故的发生。     

我省冶金矿山爆破事故原因分析及预防措施

冶金矿山作业复杂,不安全因素较多,其中爆破作业是危险性大、发生事故多的重要环节。回顾我省冶金矿山的爆破史,曾发生过多起重大爆破事故,教训是十分沉痛的。为今后减少爆破伤亡事故的发生,对过去的爆破事故进行认真总结,分析原因,找出规律,提出预防措施是十分必要的。 (一) 爆破伤亡事故基本情况从我国部分冶金矿山爆破事故情况看(见表1),天井炮烟中毒与爆破后过早进入现场占第一位;其次是导火索制做质量不佳,导致     

高耸建筑拆除爆破失控事故浅析

在烟囱、水塔类等高细建筑物的拆除爆破中,失控事故偶有发生.为吸取教训,提高爆破安全控制力度,收集一些烟囱、水塔爆破失控实例,予以分类,进行初浅分析.经分析研究表明:烟囱、水塔爆破在选取合理爆破参数的同时,还应开设定向窗,采用分段毫秒爆破.     

爆破飞石产生原因事故树分析

为了避免爆破飞石伤人事故的发生,确保爆破安全,根据现场调研,运用安全分析理论查找爆破飞石产生的原因,为爆破作业设计、施工和安全管理提供科学依据。运用事故树分析法FTA(fault tree analysis)对某一爆破飞石伤人事故进行全面、系统的分析,确定引起顶上事件发生的因素,提出相应的预防措施。     

基于事故树分析的露天爆破飞散物预防研究

为了防止露天爆破飞散物事故的发生,确保爆破施工安全,根据露天爆破作业流程,分析了爆破飞散物产生原因,建立了事故树模型,在此基础上进行了定性分析,求出事故树最小割集为15个,最小径集为4个;得到了结构重要度排序,提出了爆破飞散物事故的对策措施,可为今后的爆破设计、施工和安全管理提供参考。     

基于事故树分析的露天爆破飞散物预防研究

为了防止露天爆破飞散物事故的发生,确保爆破施工安全,根据露天爆破作业流程,分析了爆破飞散物产生原因,建立了事故树模型,在此基础上进行了定性分析,求出事故树最小割集为15个,最小径集为4个;得到了结构重要度排序,提出了爆破飞散物事故的对策措施,可为今后的爆破设计、施工和安全管理提供参考。     

某飞机轮胎爆破原因分析

飞机刹车系统故障,造成拖胎,多次发生轮胎爆破,导致严重事故,而拖胎的原因是多方面的,本工作就一起由于放气活门故障发生拖胎,造成轮胎爆破,导致事故征候的原因进行了详细分析.     

爆破工程安全评价初探

开展爆破工程安全评价可有效地减少各种危险和有害因素 ,减少爆破事故的发生 ,大型或特殊爆破工程均应进行安全评价。本文提出了对爆破工程开展安全评价的设想 ,并对爆破工程安全评价的内容和方法进行了探讨。文中指出 :根据爆破工程的特点 ,可采用事故树分析和预先危险性分析等方法进行爆破工程的安全评价     

某隧道口岩石坍塌事故分析

某隧道口坡体岩石坍塌,造成多人伤亡,国道交通中断.通过现场调查和分析.认为:几乎平行于隧道口高陡边坡面的原生开放性节理面,已使坍塌岩体处于不稳定状态,是发生坍塌事故的内因;而事故前临近的隧道小导洞掘进爆破及其违规作业加剧了节理面进一步张开和延伸,是岩石坍塌的诱因.     

城市高架桥控制爆破飞散物防护技术研究与实践

爆破飞散物是引起爆破安全事故的主要因素之一,文章针对南京城西干道高架桥爆破,系统分析了拆除爆破中爆破产生飞散物的类型和产生的原因,通过试验和爆破实践,提出了预防其危害的有效措施。对在城市复杂环境下提高爆破飞石控制的可靠性、保证拆除爆破的安全、减小爆破事故危害有重要参考意义。     

Evaluation of a leaf spring failure

The determination of the point of failure during an accident sequence of a rear leaf spring in a sport utility vehicle is presented in terms of fracture surface analysis and residual-strength estimates. Marks at the scene of the accident pointed to two possibilities for the point of failure: marks in the roadway at the start of the accident sequence and a rock strike near the end of the sequence. Evidence from rust and chemical contamination on the fracture pointed to the spring having been cracked in half prior to the accident. Extensive woody fracture and secondary cracking at the midplane of the spring was evidence for segregation and weakness in the spring. Stress estimates for the effect of both the weakness and prior cracking on the residual strength of the spring revealed reductions in strength of the spring that could produce fracture at the start of the accident sequence. The point of failure of the spring was placed at the start of the accident sequence.     

Network-level accident-mapping: Distance based pattern matching using artificial neural network

The objective of an accident-mapping algorithm is to snap traffic accidents onto the correct road segments. Assigning accidents onto the correct segments facilitate to robustly carry out some key analyses in accident research including the identification of accident hot-spots, network-level risk mapping and segment-level accident risk modelling. Existing risk mapping algorithms have some severe limitations: (i) they are not easily ‘transferable’ as the algorithms are specific to given accident datasets; (ii) they do not perform well in all road-network environments such as in areas of dense road network; and (iii) the methods used do not perform well in addressing inaccuracies inherent in and type of road environment. The purpose of this paper is to develop a new accident mapping algorithm based on the common variables observed in most accident databases (e.g. road name and type, direction of vehicle movement before the accident and recorded accident location). The challenges here are to: (i) develop a method that takes into account uncertainties inherent to the recorded traffic accident data and the underlying digital road network data, (ii) accurately determine the type and proportion of inaccuracies, and (iii) develop a robust algorithm that can be adapted for any accident set and road network of varying complexity. In order to overcome these challenges, a distance based pattern-matching approach is used to identify the correct road segment. This is based on vectors containing feature values that are common in the accident data and the network data. Since each feature does not contribute equally towards the identification of the correct road segments, an ANN approach using the single-layer perceptron is used to assist in “learning” the relative importance of each feature in the distance calculation and hence the correct link identification. The performance of the developed algorithm was evaluated based on a reference accident dataset from the UK confirming that the accuracy is much better than other methods.     

深部围压对岩体爆破损伤范围影响数值分析

深井矿山开采条件下,地应力环境更加复杂,为研究高应力围压对爆破破岩效果的影响,采用ANSYS/LS-DYNA分析软件建立了三维数值计算模型,设定开采深度H分别为1000 m、2000 m和3000 m三种方案,开展三向围压下岩体爆破损伤范围数值分析。研究表明:在相同岩石和爆破参数条件下,随着开采深度的增加,围岩压力随之增大,围压总体上对爆破损伤范围起到抑制作用,使得装药区的爆破损伤体积由H=1000 m时的2.21 m3降低至H=3000 m时的0.52 m3,降低幅度达到76.5%;且对拉伸破坏的抑制效果更明显,岩体爆破损伤类型由拉伸破坏逐渐向剪切破坏转化。高围压条件下,岩体的围岩约束作用增大,一定程度上加大了爆破难度,但超过一定范围易于诱发岩爆事故。     

The effects of automobile inspections on accident rates

To determine whether diagnostic inspections reduce assidents, this paper compares the accident rates of vehicles which participated in the Alabama Motor Vehicle Diagnostic Inspection Demonstration Program with vehicles which did not actively participate. In Huntsville the accident rate of inspected vehicles represents an improvement of 9.1% over the rate for uninspected vehicles. Furthermore, the accident rate of inspected vehicles decreased 5.3% after inspection. Whereas the monthly accident rate of the responsive participant who returned for subsequent periodic inspections did not significantly increase in eighteen months, the monthly accident rate of unresponsive participants increased to the level of uninspected vehicles. Vehicles involved in accidents were in significantly worse mechanical condition on the average than those not involved in accidents. The data suggests that poor mechanical condition is a significant factor in motor vehicle accidents and that annual inspections are a desirable means of reducing accident rates.     

Modeling secondary accidents identified by traffic shock waves

The high potential for occurrence and the negative consequences of secondary accidents make them an issue of great concern affecting freeway safety. Using accident records from a three-year period together with California interstate freeway loop data, a dynamic method for more accurate classification based on the traffic shock wave detecting method was used to identify secondary accidents. Spatio-temporal gaps between the primary and secondary accident were proven be fit via a mixture of Weibull and normal distribution. A logistic regression model was developed to investigate major factors contributing to secondary accident occurrence. Traffic shock wave speed and volume at the occurrence of a primary accident were explicitly considered in the model, as a secondary accident is defined as an accident that occurs within the spatio-temporal impact scope of the primary accident. Results show that the shock waves originating in the wake of a primary accident have a more significant impact on the likelihood of a secondary accident occurrence than the effects of traffic volume. Primary accidents with long durations can significantly increase the possibility of secondary accidents. Unsafe speed and weather are other factors contributing to secondary crash occurrence. It is strongly suggested that when police or rescue personnel arrive at the scene of an accident, they should not suddenly block, decrease, or unblock the traffic flow, but instead endeavor to control traffic in a smooth and controlled manner. Also it is important to reduce accident processing time to reduce the risk of secondary accident.     

Commentary on statistical issues underlying the evaluation of a social policy change on motor vehicle accident involvement

This commentary addresses the statistical issues which are involved in assessing whether a causal interpretation can be given to an association between a change in social policy such as lowering the legal age for drinking alcohol and a change in the nature of accident involvement frequency for a particular sub-population of drivers like 18–20 year olds. In this regard, two methodological concerns are emphasized. The first is the resolution of a possible paradox in the nature of an association in the sense that individuals with a greater tendency to accident involvement may also have a greater tendency to alcohol usage so that their alcohol related accident involvement is coincidental rather than causal. For this setting, alcohol would be an “after the fact” correlate with accident involvement as opposed to a possible cause. Similarly, the second concern is the role of population exposure as an explanation for the change in alcohol related accident frequency for a particular age group. Since availability naturally increases the size of the population at risk for such accidents, the corresponding accident frequency may similarly increase even though the corresponding accident rates may have remained unchanged or perhaps even decreased. For these reasons, although associations with change in social policy are definitely of general interest, their interpretation in a causal sense should be viewed with substantial caution until the implications of competing explanations are reconciled. This assertion, however, does not mean that such associations are not useful for policy purposes, but rather that they lack sufficiently targeted statistical validity to be the primary basis for such change. In other words, if there is a strong rationale on economic, political, or social grounds for a policy change, then data presenting meaningful associations which are compatible with it can often play an important supportive role for it.