| The Mongolian-Shaanxi mining area is an important coal base in my country.There are many new mines and large coal production.However,due to the short production time,the low degree of hydrogeological exploration,and the complex hydrogeological conditions,the mine water inflow is large,and many mines are faced with mine water hazards.threat.At the same time,Previous production and scientific research lacked in-depth analysis of of the water richness of the deep coal seam roof aquifers that cause water inrush hazards,the difficulty of roof water drainage,the lack of evaluation indicators for the drainage effect,and the lack of a mature and popularized water control technology system.Based on the in-depth study of the geological and hydrogeological conditions of the Muduchaideng coal mine,a typical mine in the Mongolia-Shaanxi mining area,the water-rich evaluation and division of the roof aquifer of the coal seam were carried out,and the normal and maximum water inflow of the mine was predicted.The development height and distribution law of the water-conducting fracture zone in the coal seam were measured and simulated,and the roof sandstone water hazard prevention and control technology integrated up and down the well was proposed.The following achievements have been obtained:(1)In-depth analysis of the geological and hydrogeological conditions of the Muduchaideng mine,by selecting the unit water inflow,sandstone thickness,geophysical anomaly index of water richness,Sandstone thickness to stratigraphic group thickness ratio,permeability coefficient and core recovery rate.According to the control factors,the“water-rich index method”was used to evaluate and partition the water-rich area of the coal seam roof aquifer,and the water-rich distribution law of the roof water was found out.The water richness of the layers is extremely uneven,and the climatic and geological conditions are relatively complex.(2)The four methods of“large well method”,“horizontal corridor method”,“single-width flow comparison method”and“multi-factor comprehensive comparison”were used to predict the mine water inflow,and the water inflow values were obtained as:3678,6911,3803,3565m~3/h,comprehensive comparative analysis showed that the calculation result of“single-width flow comparison method”was more accurate.(3)The development law of the water-conducting fractured zone was comprehensively studied by using various methods such as theoretical formula and empirical formula analytical calculation,drilling measurement,downhole television,ultrasonic imaging,and numerical simulation.The water fissure zone is approximately“saddle-shaped”,its maximum height is expected to be 136m,and the fracture-mining ratio is 24.(4)A four-in-one evaluation standard for water drainage effect was proposed,including single-hole water inflow,borehole water pressure,stable water inflow,and reasonable drainage time.The practice of evaluating the effect of water drainage engineering in the 30209 working face showed that when the average single hole water inflow of the drainage drilling hole dropped below 10m~3/h;the drilling water pressure dropped below 1.2MPa;and reasonable evacuation time;and all drilling holes within a range of 600m near the incision hole were dredged out.After a period of time,the water volume tended to be stable,and it can be determined that the effect of the water drainage project was good,and it has reached the standard of safe mining and had the conditions for safe mining.(5)On the basis of the practical experience of on-site water hazard prevention and control and the above-mentioned comprehensive research,in view of the actual conditions of the Muduchaideng mine,a comprehensive three-dimensional exploration of the geological conditions above and below the mine,the drainage of the roof of the working face and the dynamic monitoring of the mine hydrology were proposed.Trinity roof sandstone water hazard prevention and control technology.It has been proved by practice that the effect is obvious and the safety of coal mining is guaranteed.The thesis has 104 pictures,27 table,and 110 references. |
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