Study on chain effect and type of coal mine goafs instability disaster

The coal mine goafs instability disaster,especially large-area room and pillar goafs instability,has been lack of effective prediction,prevention and control.In order to study the mechanism of goafs instability,and to achieve the purpose of predictive prevention and control,based on main affecting factors analysis of coal mine goafs instability disaster,the disaster chain theory has been introduced to study the relationship of disaster formative environment,disaster formative factors,mode of action and disaster affected bodies.the chain effect structure and mathematical models of coal mine goafs instability disaster were constructed,then the basic instbility modes and types were obtained with case analysis.The results showed that,the main affecting factors of coal mine goafs instability disaster including the regional geological and tectonic distribution,the size and shape of goafs and coal pillars,the overburden and rock lithology of goafs,the hydrogeological condition,the coal mining conditions surrounding goafs,the goafs types and remaining time,static load,dynamic load,etc.The occurrence of instability disasters of coal mine goafs is closely related to the following such 4 factors as disaster formative environment,disaster formative factors,mode of action and disaster affected bodies.The chain effect structure and mathematical models of coal mine goafs instability disaster could be constructed through the study of their relationship.The basic chain instbility modes and types of coal mine goafs mainly includes 6 types,that is,the goafs instability disaster chains under the influnce of single pillar,geological structures,goafs water,mining disturbance,static load and dynamic load.The occurrence modes of each disaster chain had similarities and differences.Case shows that most of the above-mentioned six basic chain types are complex types of coal mine goaf instability.