Analysis of the causes of bridge crane accidents and safety management

桥式起重机事故原因分析及安全管理

Analysis of the causes of bridge crane accidents and safety management

引发桥式起重机起重吊运作业事故主要危险因素有：未发信号，使用不合格吊具超载吊运，安全防护装置失灵，指挥信号不明或乱指挥，吊物捆绑不牢，歪拉斜挂吊运，棱角快口没有衬垫等。在对314起起重机事故按机型分类的统计中，桥式起重机发生事故数量是59起，所占比例为18.8％，事故发生率是所有起重机械里面最高的。因此必须加强对起重作业人员的安全操作规程和规章制度教育，提高起重作业人员的安全素质。

Cause of bridge crane hoisting and lifting operation accident risk factors: no signal, the use of substandard hoist overload lifting, safety protection device failure, the command signal is unknown or arbitrary command, hanging binding is not strong, crooked pull over the lifting, angular openings no liner etc.. In 314 crane accidents according to statistical models classification, bridge crane accident number is 59, the proportion of 18.8%, the accident rate is the highest of all hoisting machinery. It is necessary to strengthen the operation rules and regulations on safety education for lifting personnel, improve the safety quality of lifting operation personnel.

　　1起重机的机械事故

1 crane machine accidents

　　起重伤害与事故是指起重机械在作业过程中，由机具、吊物等所引起的人身伤亡或设备损坏事故。据统计，在冶金、机电、铁路、港口、建筑等生产部门，起重机械所发生的事故占有很大比例，高达25％左右，其中死亡事故占15％左右。如表1所示，其中在吊具打击中，有3起脱钩事故，占吊具打击事故的50％；在断绳事故中，有5起过卷事故，占断绳事故的38.5％；在108起事故中，有2起是超载事故，占事故总数的1.9％。据统计结果可知，在108起典型起重伤害事故中，吊物脱落打击事故占总事故数的25％，其伤亡人数占总伤亡人数的20.7％，居首位；其次是断绳伤害事故，分别为12％和12.1％；居第3位的是挤压伤害事故，分别为12％和9.3％。由此可见，吊物脱落打击、断绳和挤压伤害事故是起重机械作业过程中的多发性事故。

Lifting injury and accident refers to the hoisting machinery in the process of the operation, caused by a machine, hanging, personal injury or equipment damage accidents. According to statistics, in metallurgy, machinery, railway, port, building the production department, the occurrence of heavy machinery accident occupies a large proportion, as high as 25%, which accounted for about 15% of deaths. As shown in Table 1, which in the sling blow, 3 blow from accidents, accounting for 50% of accident in a sling; rope break accident, there are 5 overwinding accident, accounting for rope-broken accident of 38.5%; in 108 cases, 2 were overload accident, accounting for 1.9% of the total number of accidents. According to the statistical results, in 108 typical lifting injury accident, hanging off against accidents accounted for the total number of accidents 25%, the death toll accounts for the total of 20.7% casualties, the first; followed by the rope break accident, respectively 12% and 12.1%; ranked third is crush injury accident, respectively. 12% and 9.3%. Thus, the hanging off the blow, rope and crush injury is the hoisting machinery in the process of operation of multiple accidents.

　　2桥式起重机重大事故的分析

Analysis of 2 major accidents of bridge crane

　　事故树分析又称为故障树分析或事故逻辑分析,它是对系统安全性进行定性与定量分析评价的一种科学的和先进的方法，已被广泛地运用到现代设计的多个领域之中。事故树分析评价是运用由事件符号和逻辑符号组成的一种图形模式，来分析人机系统中导致灾害事故的各种因素之间的因果关系和逻辑关系，从而判明系统运行当中，各种事故发生的途径和重点环节，为有效地控制，提供一个简洁而形象的途径。在作业过程中，由于人的失误、机器故障、环境影响，随时都有可能发生不同程度的事故。为了不使这些事故导致灾害性后果就要对系统中可能发生事故的各种不安全因素进行分析和预测，以采取相应的措施和手段来防止和消除危险。因此一个系统的事故分析应包括：系统可能发生灾害事故，也称为顶上事件；系统内固有的或潜在的事故因素，包括人、机器、环境因素；各个子系统及各因素之间的相互联系与制约关系，即输入—输出的因果逻辑关系，并用专门的符号表示；计算系统的顶上事件的发生概率，进行定量分析与评价。

Fault tree analysis and analysis of fault tree analysis or accident logic, it is for the qualitative and quantitative analysis and evaluation of the security of the system is a scientific and advanced method, has been widely applied to many fields of modern design. Fault tree analysis evaluation is the use of a graphical model consisting of event symbols and symbolic logic, to analyze the causation and the logical relationship between the various factors causing disasters in man-machine system, so as to ascertain the system operation, approach and key links of various accidents, in order to effectively control, provides a concise and vivid the way. In the course of the operation, due to errors, machine failure, environment influence people, may occur at any time of the accident. In order not to make these accidents lead to disastrous consequences will be unsafe for the various possible accident system of factor analysis and prediction, to take corresponding measures and means to prevent and eliminate the risk of. Therefore, a systematic analysis of accident should include: the system may occur accident, also known as the top event; factors in the system inherent or potential accidents, including man, machine, environment factors; between each subsystem and each factor mutual connection and restriction, namely the input - output of the causal relation, and is represented by special symbols; the happening probability of the top event system, analysis and quantitative evaluation.

　　2.1事故树分析程序

　　把事故树的分析过程采用1个系统图形建立起来，如图1所示。

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　　2.2事故树的建立

　　2.2.1建立事故树图

　　顶上事件：吊物挤、撞打击伤害。吊车事故图见图2。

　　2.2.2事故树分析

　　事故树的割集：

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　　事故树的径集：

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　　2.3结构重要度计算

　　导致顶事件发生的基本事件很多，在采取防止顶事件发生措施时应该分清轻重缓急，优先解决那些比较重要的问题，首先消除或控制那些对顶事件影响重大的基本事件。在故障树分析中，用基本事件重要度来衡量某一基本事件对顶事件影响的大小。基本事件的结构重要度取决它们在故障树结构中的位置。评价基本事件结构重要度的方法：根据基本事件在最小割集中出现的情况评价在由较少基本事件组成的最小割集合中出现的基本事件，其结构重要度较大；在不同最小割集合中出现次数多基本事件，其结构重要度大。可按下式计算第1个基本事件的结构重要度：

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　　式中k——故障树包含的最小割集数目；

　　m——包含第i个基本事件的最小割集数目；

　　Rj——包含第i个基本事件的第j个最小割集中基本事件的数目。

　　采用事故树分析软件得出该事故树的结构重要度顺序为：

　　I(17)>I(14)=I(15)=I(16)>I(8)=I(12)=I(6)=I

　　(7)=I(9)=I(10)=I(11)=I(13)=I(2)=I(3)=I(4)=I

　　(1)=I(5)