Water Resisting Property Of Ordovician Limestone Top In North China Coal Field And Its Utilization And Grouting Reconstruction

With the rapid development of the coal industry,the shallow coal resources in North China are gradually depleted,and gradually extended to the deep mining.Deep coal seams is close to the Ordovician limestone aquifer,the pressure of the Ordovician limestone karst water is high,water quantity is big,Many mining floor of the Ordovician limestone water inrush coefficient has exceeds the critical value,Water hazards have taken place frequently,Due to the water abundance of Ordovician limestone aquifer is good,so the traditional hydrophobic step-down method is difficult to achieve the effect,and the mining area of groundwater environment can cause damage.It is contrary with the concept which is "water preserved mining,green mining ".Therefore,it needs urgently to research the new technology of coal bed exploitation under the high pressure.This paper formed a set of technology of Ordovician limestone aquifer top utilization and grouting reconstruction,to recognize the water abundance and water isolation on Ordovician limestone top,and to realize the new period of coal bed exploitation under the high pressure,which has pioneering significance.Based on field investigation for the six major mining area in the north China type coal field,summarizes the various mining top Ordovician limestone karst features,proposed Ordovician limestone sedimentary evolution.Using research ideas "flat partition,vertical zoning ",the water abundance and water isolation on ordovician limestone top characteristics were investigated systematically,forming a top Ordovician limestone karst water-rich evaluation system proposed test weights for calibration method based on the estimated coefficient correction method to achieve the top Ordovician limestone karst water-rich quantitative evaluation;proposes Ordovician limestone top vertical zoning characteristics of the top-down into the top of Ordovician limestone weathering filled with water blocking,with a vertical guide liters of water and invasion karst fissure water-rich zone.From laboratory tests,space-situ tests and regional stratigraphic distribution of multiple scales characteristics of a comprehensive study of Ordovician limestone water resistance performance of the top filled with weathered its feasibility impermeable layer utilization.The results show that the top of Ordovician limestone have weathered filled with reliable strength,good water resistance properties and other characteristics,in the case of distribution of stability,structure and other external disturbances by low-impact,feasible as impermeable layer utilization.Forming a top Ordovician limestone utilization and grouting reconstruction integrated technology system.The establishment of a top Ordovician limestone water-blocking segment and use criterion aqueous paragraph grouting transformation,a method to determine the top Ordovician limestone grouting reconstruction thickness,theoretical analysis,laboratory experiments and formula derivation and other methods are used to study the top Ordovician limestone karst fractured media slurry diffusion law and proposes optimized formula Keogh fly ash top grouting material.According to Hancheng Sangshuping Mining Area's and Xingtai Dongpang Mining Area's conducted applied research projects of the ordovician limestone aquifer top utilization and grouting reconstruction.In Hancheng Sangshuping Coal Mining,3105 Face to face as a test,applied research project at the top of Ordovician Limestone use of technology to achieve a safe working face mining;in Xingtai Dongpang Coal Mining,9201 Face to face as a test,carried out by the application of Ordovician limestone top research and technology renovation project,will Dongpang 9201 Face transformed into top impermeable layer,to achieve safe mining conditions.The two project examples for understanding the water abundance and water isolation on Ordovician limestone top,and the Ordovician limestone aquifer top utilization and grouting reconstruction technology system was verified.