Analysis On Distribution Rule And Cause Mechanism Of Main Hidden Disaster Causing Factors In Coal Mines In Hebei Province

This paper takes the hidden disaster-causing factors of major coal mines in Hebei province as the research object,and analyzes them from the aspects of weight,distribution rules and genetic mechanism.Firstly,the main hidden disaster-causing factors are determined by data statistics,and their weights are determined by AHP analytic hierarchy process.Secondly,the distribution rules are analyzed by mathematical statistics and data comparison,and finally the genetic mechanism is studied by analyzing geological structure,coal seam characteristics and human engineering activities.According to its weight,distribution law and cause of formation mechanism put forward the targeted governance measures.According to the research and analysis,the main hidden disaster factors in Hebei province are goaf,Ordovician limestone water,collapse column,gas,spontaneous combustion of coal seam,fault,water guide fracture zone,poor sealing borehole,and abandoned old kiln.Among them,goaf,gas,water fracture zone and poor sealing boreholes are mainly distributed in northwest Hebei and south Hebei.The Ordovician limestone water,faults and collapse columns are mainly distributed in the south of Hebei province.Coal spontaneous combustion and abandoned old kilns are mainly distributed in northwest Hebei province.The disaster causing mechanism of goaf is mainly caused by human engineering activities such as blasting and different rock thickness,which leads to lower surrounding rock strength,resulting in collapse and water accumulation.The cause of Ordovician limestone water disaster is mainly caused by the special geological structure movement,which causes water to enter the rock to dissolve and crack into Ordovician limestone water and cause water inrush.The genetic mechanism of collapse column is mainly caused by the collapse of karst cave under the long-term ground stress and gravity of overlying strata,leading to the collapse of coal seam and the formation of irregular column of collapse.The cause of gas disaster is mainly due to the large change of coal seam thickness or the special geological tectonic movement such as fault folding,which causes stress concentration and the high degree of coal metamorphism.The genetic mechanism of spontaneous combustion of coal seam is mainly caused by human factors such as medium ash,low sulfur and high calorific value,second-grade spontaneous combustion tendency,and unreasonable vent setting.The mechanism of fault disaster is mainly caused by human excavation project,which causes fault activation,changes fault conductivity,and leads to the formation of water-rich fault.The formation mechanism of water-conducting fracture zone is mainly that the roof and floor of coal seam are damaged by coal mining activities,and water enters into the coal seam through cracks,and structural fractures such as joints and faults increase the water-rich strata.The roof of coal seam contains strong water-rich aquifers.The mechanism of sealing the bad borehole is mainly due to the dotted vertical guide water passage left by human engineering activities and the lax construction requirements in 1980 s.The cause of formation of abandoned old kilns is mainly that in 1990 s,there were too many small kilns and small mines around them.