Analysis On Unsafe Acts Of Gas Coal Mines Gas Explosion Accidents In China

In recent years, severe gas explosion accidents frequently occur in coal mines in China. To prevent gas explosion accidents, the most important strategy is to solve one direct cause of the accident, i.e. the unsafe condition, by using engineering technology, but there are few studies on the solution of unsafe act, which is another direct cause of the accident. The main method to reduce or eliminate the unsafe act is taking intensive safety inspection. Once the staff’s unsafe action is checked, drastic measures such as Punishment and stop will be adopted, which is called "instant" solution. But the "instant" solution has not durable effect and it is difficult to establish long-term effective mechanism of safety in production by adopting the solution. Research data indicate that gas coal mine share more than 70% of the total coal mine, and coal mine gas accidents accounted for more than 35% of the total coal mine accidents. In the severe gas explosion accidents, gas explosion accidents in gas mines hold more than 42% of the gas explosion accidents. Therefore, it is necessary and of practical significance to study the gas explosion accident. In order to solve the unsafe act associated to gas explosion accidents, gas explosion accidents, gas explosion based on human error unsafe action types, key unsafe action of prevention and control measures are studied by adopting statistical analysis method and theoretical analysis method. The main research results are as follow:(1) The essential conditions of gas explosion include the simultaneous existence of a certain concentration of gas, high temperature fire and enough oxygen. Statistical analysis shows that human factors which result in major accidents accounts for 97.67% the direct cause of the accident in all coal mine in our country, accounting for 96.59% of catastrophic gas explosion accidents. The human factors have actual performance of improper behavior control, namely people’s unsafe action, in the process of mining and production. Personal unsafe actions including two aspects: one-time unsafe act and habitual unsafe act. The former is the specific action in the moment of accident caused by accident releaser, which is the direct reason of accident. And the latter can be one or several of safety knowledge, safety consciousness and safety habit, which is as indirect accident reason producing accident reason of habitual unsafe behavior directly. Using the behavior safety "2-4" model, 84 gas explosion accidents are analyzed and unsafety action library of gas explosion accident is established. Based on unsafe actions and the unsafe state of matter which cause coal mine gas explosion accidents, the paper analyzes the causes of gas explosion. It is concluded that there are respectively 32 and 27 kinds of sources of gas accumulation and fire which may cause gas explosion. The gas accumulation is inclined to occur in the coal mining face, excavating face and goaf. Unsafe action and unsafe state of matter causing gas accumulation are: coal and gas outburst, gas emission, gas accumulation in blind alley, etc. Ignition sources in mine contain electrostatic sparks, roof caving rock collision sparks, shooting, etc.(2) Based on the theory of human error and organizational management, unsafe action which may lead to gas explosion is divided into four types, which are respectively skilled-based unsafe act, decision-based unsafe act, perceptual unsafe act and violation unsafe act. Through the statistical analysis of unsafe action in 84 incident cases, results are obtained: 1) Skilled-based unsafe act happens a total of 59 times and hole sealing construction without the use of water stemming, shooting unchecked hole whether qualified, local ventilator installation position error, random stop local ventilator and the number of "scatter to the winds" gas drainage are in the top five; 2) Decision-based unsafe act happen a total of 15 times, including untreated without wind area, failed to timely will be affected by the wind flow short circuit area blackout from people, unplanned outage to main ventilator and local fan stop stalling the wind and the gob fire area not controlled targeted fire prevention measures which are ranked in the top four; 3) Perceptual unsafe act happen a total of 40 times, including knock hit remove the miner’s lamp, not delay ram(ram distance drivage head too far), shooting is not used to make metal mining emulsion explosive, downhole maintenance collision produced sparks and random open throttle makes merry short circuit which are ranked in the top five; 4) Violation unsafe act happen a total of 190 times, which is more than the sum of above three kinds of action, including fails to detect the gas concentration, the execution "before the" three chain "and" three inspection "a gun system, super cross-border combat digging, working face in the work under the condition of no wind or breeze and detect roadway, the failed outage time from a human hair on frequency which ranked in the top five.(3) Through statistical analysis of the different types of employees’ unsafe action, the gas accident different types of employees’ unsafe action are identified and classified. Then 9 kinds of unsafe actions related to gas explosion are concluded. Downhole electric workers have 8 kinds of unsafe action in total, in which "give no wind area electrical equipment power" and "electric repair electrical equipment" occur most frequently; Downhole blasting workers have 10 kinds of unsafe action in total, in which "seal hole without the use of water stemming" occur most frequently; Ventilation workers have 16 kinds of unsafe action in total, in which "working face in the work under the condition of no wind " occur most frequently; Gas inspection workers have 10 kinds of unsafe action in total, in which "no detecting the gas concentration before the operation " occur most frequently; Safety inspectors have 6 kinds of unsafe action in total, in which "failing to timely check and deal with the blind alley of roadway and scrap"; Transportation operation workers have 5 kinds of unsafe actions in total, in which "pull electric cable" occur most frequently; Mining operation workers have 16 kinds of unsafe action in total, in which "illegal entry without wind job location" occur most frequently; Grass-roots management personals have 6 kinds of unsafe action in total, in which " smoking in underground " occurs most frequently; Senior management personals have 8 kinds of unsafe action in total, in which "super cross-border, combat digging" occurs most frequently. At the same time, the common types of unsafe actions can be defined and classified to 9 kinds of common unsafe action, which respectively are: enter the windless job site after the operation, stop the wind power into the airtight operation, continue to work not measures and into the mined-out area, continue to work the roadway, the area, optional shut down local ventilator, optional open to make metal friction damper, operating equipment tools impact, pull electric cable. And the violation unsafe act type in common unsafe action more than other three types.(4) According to the grey theory and entropy theory, grey comprehensive evaluation model of entropy specific to unsafe action in sample mine is established. On the basis of comprehensive evaluation model, it is known that the greater the result is, the higher the importance degree of unsafe act, and so the unsafe act is key types of act in these kinds of mine. Comprehensive associated values are sorted and the order is relative superiority order of each index sequence, which can be used to evaluate the safety level gap between the types of mines and other mine and provides an important basis for the same type of the mine to avoid gas explosion. Statistical analysis of the unsafe action in 84 gas explosion cases is carried out and the comprehensive associated values are calculated. The larger five unsafe actions of each category number are sorted, and the following conclusion are obtained: the unsafe action in large mine mainly include: no checking the workplace of the gas concent ration during operation, hole sealing without being crammed by water stemming, no power cut and withdraw after detection of gas exceeding the limit, no implement the system of "three inspection" a gun and pull electric cable; The unsafe actions in medium mine mainly include: no detecting the gas concentration before operation, no implement "three chain" and "three inspection" a gun system, unqualified airtight construction quality, long-standing gob fire area without taking targeted fire prevention measures to control, no checking gas concentration in place in working face of fault fracture zone security hidden danger; The unsafe action in small mine mainly include: no implement "three chain" and "three inspection" a gun system, no detecting the gas concentration before operation, smoking, no installing local fan or not ventilation in underground tunneling faces; Unsafe actions in the miniature mine mainly include: no power cut and withdraw after detection of gas exceeding the limit, no detecting the gas concentration before operation, hole sealing without being crammed by water stemming, no implement "three chain" and "three inspection" a gun system and cross-border and illegal organization production; The unsafe actions in villages and towns coal mine mainly include: operation into the breeze or windless place, no detecting the gas concentration before operation, blasting hole sealing without being crammed by water stemming, no power cut and withdraw after detection of gas exceeding the limit and no implement "three chain" and "three inspection" a gun system; The unsafe actions in key state-owned coal mine mainly include: no implement "three chain" and "three inspection" a gun system, no detecting the gas concentration before operation, electric coal drill with exposed joint being used, super layer cross-border, digging and blasting, hole sealing without being crammed by water stemming; Unsafe actions in coal mines in Shanxi mainly include: sealing hole without the use of water stemming, no detecting the gas concentration before operation, no implement "three chain" and "three inspection" a gun system, operation into the breeze or windless place, electric coal drill with exposed joint being used; Unsafe actions in coal mines in Heilongjiang mainly include: sealing hole without the use of water stemming, no implement "three chain" and "three inspection" a gun system, operation into the breeze or windless place; no lengthening the duct in time, the distance between the duct and coalface being too far and random demolition of airtight, operation into the windless place; Unsafe actions in coal mines in Henan mainly include: no treating the area with no wind, no power cut and withdraw after detection of gas exceeding the limit, electrician electric repair electrical switch and led cable short circuit to spark, blasting and no installing ventilation facilities; Unsafe actions in coal mine in Shaanxi mainly include: residual workplace of gas concentration, super cross-border and combat digging, failing to timely withdraw from mine tunnel under the condition of no wind and no power, the distance between the duct and coalface being too far, hole sealing without being crammed by water stemming; Unsafe actions in coal mines in Inner Mongolia mainly include: no detecting the gas concentration before operation, pull electric cable(cable is pulled a short circuit to produce edm), failing to timely handling roof caving, local ventilator installation position error and no implement "three chain" and "three inspection" a gun system; Unsafe actions in coal mines in Guizhou mainly include: tunneling working face head-on not delay to ram, no installing ventilation facilities, local ventilator installation position error, using the exposure blasting bus and tapping or remove the cap lamp; Unsafe action in coal mines in Liaoning mainly include: blasting without using water cannon mudding hole, gas drainage measures, exposure blasting, mining working face unrealized independent ventilation and blasting operation without implement "three chain" and "three inspection" a gun system.(5) On the basis of the above research results, the prevention and control suggestions on the key unsafe action are put forward. In order to control and prevent the occurrence of the key unsafe action, firstly, enterprise staff and leadership need safety training, such as professional skills, safety knowledge, safety awareness, etc. And for different types of key unsafe action, the corresponding control methods are also established. In the process of statistical analysis of skilled-based unsafe act, " hole sealing without being crammed by water stemming " occur most frequently, up to 20 times; The occurred frequency “Unchecked blasting hole ", " partial ventilator installation position error " and " random stop local ventilator " are all 5 times. For these unsafe actions, the method of video teaching method and application of virtual reality can be adopted to control. In the process of statistical analysis of perceptual unsafe act, this action, " tapping, bump, remove the cap lamp ", has the most frequency, six times; " Not delay to ram, ram distance drivage head too far " occurred five times; The occurred frequency of " When shooting unused mine emulsion explosive " is 4 times. Watching the three dimensional animation can be used to control these unsafe actions. In the process of statistical analysis of violation unsafe act, such action are significantly more than other types in aspect of frequency, among them " no detecting the gas concentration before operation " has the most frequency, reached to 32, no implement " three chain " and " three inspection " a gun system have 28 times, " cross-border, combat digging " occurred 16 times, " operation into the breeze or windless place " happened 15 times, no power cut and withdraw after detection of gas exceeding the limit" occurred 12 times. Aiming at these unsafe actions, the family education mode and the case study video methods can be used to control. In the process of statistical analysis of decision-based unsafe act, this kind of action happens less than cognitive type; violate compasses type and skilled-based unsafe act in aspect of frequency, in which the action "untreated area without wind" has the most frequency, six times; The frequencies of " no power cut and withdraw in area affected by the romantic short circuit area" and "unplanned outage to main ventilator and local ventilator stops, stopping wind" are both 2 times. To this unsafe action, the training which is used to improve decision ability to the enterprise top management can be adopted to prevent and control.