Research On Forecast Of Water Bursting Risk Zoning On Roof Coal In Zhang Jiamao Mine

Mine water disasters cause great difficulties to the safety of coal mining, and alsothreaten the lives of the miners in China’s coal mining. The shallow multi-seam mining isburied shallow, and the water resources which can cause water harmed of roof were plenty,but there isn’t come up with a reasonable prediction to water burst of roof bout shallowmulti-coal seam roof bay. This paper takes zhang jiamao mine as the study area to predict thegushed or flew water risk of roof aquife in shallow multi-seam mining. This study has a greatpractical significance not only for the risk zoning prediction about the rich seam, but also forthe prevention of roof flood in Jurassic Coal Field in Northern Shaanxi Province and similarcoal field.Through the comprehensive analysis of past data, we summary geological andhydrogeological conditions of Zhang Jiamao Idas systematically. As to the water fillingconditions, we considers the main water filling sources of Zhang Jiamao Idas multi-seammining were Quaternary loose bed overlying, weathered bedrock and groundwater of burntrocks aquifer, surface channel flood and coal seam goaf hydrops overlying; the mainpassageway of water was water flowing fractured zone of the overburden rock under mining.The water filling intensity was different in different regions and different water fillingfactors. The calculating formula of flood discharge in small drainage basin is used tocalculate the size of flood discharge in different rainfall conditions and different locations,which is divided into large, more, medium and small four levels according to the size of itwhen combined with the discharge capacity of mine. We divide and predict rich degree intostrong, medium, weak and very weak four levels to draw its forecast zoning map of mainwater filling and water aquifer seams such as ida loose bed, weathered bedrock and burntrocks. Taking big well method as basis, we calculate the volume and speed of hydrops aboutgoaf overlying, and in accordance with the speed of hydrops water, we divide it into strongwater-rich, middle water-rich, weak water-rich and very weak water-rich four levels for the research of rich degree to draw the zoningprediction map of rich degree about the major coalseam goaf area overlying. For the research of the safety zoning in ida break safety division，we calculate the development height of water flowing fractured zone about the main coallayer according to the empirical formula. Taking the maximum as key indes to determinesafety or unsafety division of break to draw the zoning prediction map of safety division ofbreakabout the main coal layers. This study proposesthe size of risk classification predictors,standards and superimposed prediction methods in water bursting on roof coal to draw thecomprehensive zoningprediction map of the size of the water burst risk about Zhang jiamaomajor coal seam.