The Study On Unsafe Act Causes For Coal Mine Flooding Accident

Flooding accident ranks the second in China coal mine accident which resulted in large numbers of deaths and injuries. Although the overall safety situation of coal mine has been improved in recent years, flooding accident still occurs from time to time, and the death toll and the number of flooding accidents have a rising proportion in major & particular major coal mine accidents. Therefore, it is an important and urgent issue to strengthen the reason analysis and preventative study on coal mine flooding accident. Method of Behavior-Based Safety has received more and more attention in the field of accident prevention, but there is still much room for improvement in current coal mine study.In order to prevent coal mine flooding accident and provide the coal mine enterprises and practitioners with simple and practical accident prevention advice and results, this paper chose the accident causation ―2-4‖ model as its theoretical basis and analysis tools, used accident statistics method, researched into the unsafe acts causing 160 less severe and above coal mine flooding accidents from 1990 to 2012.Firstly, unsafe act causing these 160 accidents were analyzed; secondly, 746 unsafe acts were obtained, they were numbered one by one and classified into four levels ―time, piece, kind, category‖ referring to a botanical classification method; thirdly, databases were established for unsafe acts; types of unsafe act, unsafe act owner, staff level, types of regulation violation, changes of unsafe act were studied and features and characteristics were gotten. Finally, a behavioral safety accident prevention training system for coal mine flooding accident was established based on the above research. The main conclusions are as follows.(1) The macro features of coal mine flooding accident were obtained. Although the number and death toll of coal mine flooding accident are on the decline from 2000 to 2014, the percentages they take of major and particular major accident are on the rising. When researched into the ownership from 2006 to 2014, it is found that the number of accident and deaths toll of township coal mine both take more than 70% of flooding accident; and when researched into the accident location from 2007 to 2014, it is found that tunneling face ranked the first, which takes 65% of the number of flooding accident.(2) The unsafe act were numbered and classified. 746 unsafe acts from 160 flooding accidents were numbered and classified into four levels ―time, piece, kind, category‖ referring to a botanical classification method, so as to establish the corresponding relationship between unsafe acts and accidents, laying the foundation for analysis and training.(3) All-unsafe act database and direct unsafe act database were established and their characteristics were gotten. For all-unsafe acts, the main task is to prevent the unsafe act relating to detecting and removing water; for direct unsafe acts, the main task is to prevent ―illegal commanding after finding the symptom of flooding‖ and ―illegal blasting‖. The database of all-unsafe acts of coal mine flooding accident includes 21 categories, 69 kinds, 213 pieces and 746 times unsafe acts. ―Failed to take effective measures to detect and remove water‖ ranks the first in 69 kinds of all unsafe acts, and it appears 66.25 times per 100 accidents on average; ―failed to detect and remove water effectively‖ ranks the first in 21 categories of all-unsafe acts, and it appears 88.68 times per 100 accidents on average. The database of direct unsafe acts of coal mine flooding accident includes 10 categories, 27 kinds, 54 pieces and 160 times unsafe acts. ―Illegal commanding after finding the symptom of flooding‖ caused 30 accidents directly, the most in the 27 kinds of direct unsafe acts; ―illegal blasting‖ caused 45 accidents directly, which is the most in the direct unsafe acts categories.(4) The characteristics of unsafe act database, staff level and unsafe act owner in township coal mine were acquired after research. The main task for township coal mine is to prevent the unsafe acts by senior management staff. For senior management staff the main target is to prevent ―failed to take effective measures to detect and remove water‖ and other 43 kinds of unsafe acts by mine director; for middle management staff, the main target is to prevent the unsafe act ―failed to detect condition of hydrogeology‖ by chief in detection department; for team leader and fist-line workers, the main target is to prevent the unsafe acts mainly related to blasting. An unsafe act database of township coal mine flooding accident was set up, including 115 flooding accidents, 565 times unsafe act, and 959 man-times unsafe act. ―Failed to detect and remove water effectively‖ takes the largest proportion in 21 categories of unsafe acts in township coal mines, reaching 90.43 times per 100 accidents; “illegal commanding”and ―failed to detect condition of hydrogeology‖ both have reached more than 50 times in every 100 accidents. Studying on staff level revealed that the percentage of man-time unsafe acts by senior management staff, middle management staff, team leader, first-line workers and external organizational staff accounted for 77.01%, 2.51%, 6.79%, 13.27%, 0.42% respectively of total man-time number in township coal mine. The percentage shows flooding accident in township coal mine is mainly caused by unsafe act by senior management staff. When unsafe act owners in all staff levels were researched, it is found that the unsafe act by mine director is the highest in senior management staff up to 61.33%; and their unsafe act include ―failed to take effective measures to detect and remove water‖ and other 43 kinds. The man-times unsafe act by chief in detection department accounted for 87.5% of middle management staff; their main unsafe act is ―failed to detect condition of hydrogeology‖. The main unsafe acts by team leader are ―illegal blasting after finding the symptom of flooding‖ and ―illegal blasting when working in flooding threatened area‖, taking 64.62% unsafe act from team leader. The unsafe act by blaster is the most in first-line workers, and the main unsafe act are ―illegal blasting after finding the symptom of flooding‖ and ―illegal blasting when working in flooding threatened area‖, both accounting for 87.50% of its own unsafe acts.(5)The unsafe act characteristics of state-owned local coal mine and state-owned key coal mine are obtained. State-owned local coal mine shares the same staff level order with township coal mine, while the state-owned key coal mine should also pay attention to unsafe act by middle management staff, in addition to senior management staff. For unsafe act owner, there is an even distribution of unsafe acts by team leader in state-owned local coal mine and first-line workers in state-owned key coal mine, while characteristics of the unsafe acts of mine director and chief in detection department is similar to that of township coal mine. The unsafe act databases of state-owned local coal mine and state-owned key coal mine were established. The state-owned local coal mine database includes 23 accidents, 103 times unsafe acts and 183 man-times unsafe acts; state-owned key coal mine database includes 22 accidents, 78 times unsafe acts, and 125 man-times unsafe acts. By studying on unsafe act types, for the unsafe act which is more than 70 man-times in 100 accident on average, the state-owned local coal mine includes two categories ―failed to detect and remove water effectively‖ and “illegal commanding‖, and the state-owned key coal mine includes one category ―failed to detect and remove water effectively‖. By studying on staff level, it is found that the tendency of state-owned local coal mine is similar to township coal mine, while the state-owned key coal mine is different. The unsafe act number ratio of senior management staff in state-owned key coal mine is 79.20%, middle management staff 8.80%, first-line workers 6.40%, external organization staff 4.40% and team leader 1.60%. The result shows that state-owned key coal mine should also pay attention to unsafe acts by middle management staff. By studying unsafe act owner and unsafe act types, there is an even distribution of unsafe acts between team leader in state-owned local coal mine and first-line workers in state-owned key coal mine, other corresponding features are similar to township coal mine, but the specific proportions are different.(6) By study on the types of regulation violation, ―illegal commanding‖ takes the most proportion in all coal mines, the number of man-time accounts for 74.38% on average, and ―illegal operation‖ ranks the second.(7) The unsafe act characteristics changed with unsafe act types, unsafe act location and time in coal mine flooding accident are obtained. ―Illegal construction‖, ―adopting forbidden coal winning technology‖ and other 3 categories of unsafe acts have been eradicated in some coal mines in addition to preventing ―failed to detect and remove water effectively‖, the emphasis should be put on ―illegal commanding‖ and other unsafe acts for flooding accident prevention in the tunneling face; when considering time changes, 20 kinds of newly emerged unsafe acts and 13 kinds of unsafe act whose proportions increase are the focus in future flooding prevention. By studying on unsafe act types in different kinds of coal mines, "illegal construction" has been eliminated in state-owned local coal mine, and ―adopting forbidden coal winning technology‖ and other 3 categories of unsafe acts have been eliminated in state-owned key coal mine. It is well worth for different ownership types of coal mines to learn from each other. By studying unsafe act location in different kinds of coal mines, tunneling face has the most unsafe act in all types of mines, accounting for more than 43.14% in the total number of unsafe act. For flooding accident prevention at tunneling face in different coal mines, in addition to eliminate the unsafe act ―failed to detect and remove water effectively‖, township coal mine and state-owned local coal mine still need to prevent "illegal commanding" and "unauthorized production without basic equipment and conditions‖, and state-owned key coal mine needs to prevent "failed to receive safety training" and "failed to evacuate after finding symptom of flooding". Divided unsafe act into two groups in accordance with time, there are 20 kinds of unsafe acts newly added, including "failed to inform the next coal mine after accident happened‖, and 15 kinds of unsafe act disappeared in recent years. By contrast, the proportion of 13 kinds of unsafe act has increased, including ―unauthorized production during the shutdown". And unsafe acts of the newly added 20 kinds and proportion increased 13 kinds should be the important unsafe act for flooding accident prevention in the near future.(8)To prevent unsafe acts in coal mine flooding accident, a behavioral safety training system for coal mine flooding accident has been set up with my research group.