爆破工程中电爆网络拒爆事故分析及对策

Countermeasures against the power-transmission network blasting through the misfire accident analysis based on the blasting engineering theory

爆破作业在各类工程项目中的应用越来越广泛,尽管爆破技术经历了较长时间的发展,但在爆破作业中的各类事故仍常有发生,其中拒爆事故不但令爆破技术人员非常棘手,也给处理拒爆事故的作业人员带来人身安全方面的威胁。应用安全系统工程的主要方法——事故树分析(FTA),对爆破工程中常用的电爆网络进行了分析。通过定性分析,求出了树的最小割集、最小径集及基本事件的结构重要度系数;通过拒爆事故影响因素的分析,计算出了拒爆事故发生的概率,并相应提出了降低拒爆事故发生概率的措施。

This article takes as the target of its research topic the likely countermeasures against the power-transmission network blasts through misfire accident analysis. In this paper,we have done detailed analyses over the commonly met accidents,known as the top events（ misfire accidents） by FTA method and the generally approaches to the safety management and the available technical measures to be taken to prevent such accidents and ensure the safety production. Therefore,based on the investigation and analysis,we have confirmed that there may exist five factors that may lead to the above said misfires：（ 1） the quality of blasting net;（ 2） the status in situ of the detonator;（ 3） the status in situ of primer;（ 4） that of the explosives;（ 5） the quality of the loaded explosives. All the aforementioned five factors are likely to formulate the fault tree of misfire accidents on the electric blasting network. Through the qualitative analysis,it would be possible for us to arrive at the minimum cut sets and the minimum path sets of FTA and then work out the structure weights of each basic event. And finally,we have also arrived at the accident probability through the evaluation of each factor. On the basis of the above said calculation,we would like to propose the following two measures to reduce the probability rate of misfire accidents as follows：（ 1） Considering the blasting net itself,it is necessary to take the dual detonating network to improve the redundancy of the blasting network;（ 2） With the help of advanced safety testing and management devices,it would be possible for us to strengthen the safety management of such aspects as man,equipment and facilities as well as the environment. What is more,the video monitoring system can be made highly effective for the safety management of blasting. The actual probability of misfire accidents is0. 054 92 with the single detonating network and 0. 002 658 by using the dual detonating network. The calculation shows that the use of detonating network can greatly reduce the probability of the misfire accidents so as to effectively control and in turn reduce the misfire accidents. All the measures we have taken above can help to promote a faithful reference to the blasting operation and control.