| Mining subsidence threatens social security and causes huge economic losses,which leads to damage the facilities,such as electric tower and high voltage line,and which affects the operation of web of life such as social power communication.Therefore,it is very important to evaluate the stability and safety of the transmission line iron tower in the mining area,the deformation law of transmission tower under the influence of coal seam mining,and the determination of reasonable mining method about the coal seam.The transmission line iron tower in Datong coke coal mining areas was taken into accord.In this paper,theoretical analysis,field measurement,laboratory test and numerical simulation method were adopted to focus on the surface subsidence rules of 4~#coal seam mining,the measured laws of mining surface movement,relationship between the mining subsidence and damage characteristics below the surface of high voltage power supply tower.The multi-seam mining surface movement regularity,the multi-seam mining layout optimization protection ways were also investigated.The paste backfilling mining was also put forward to protect the tower of high voltage power supply.Above all,some innovative achievements were presented.In order to reveal 4~#coal mining surface movement rules of 8503 working face in the coking coal mine,and predict the influence on of the surface movement deformation caused by 4~#coal seam mining to iron towers of high voltage power supply.According to prediction theory of mountain surface movement and deformation,combined with the technology conditions of 4~#coal seam mining in coking coal mine,5 parameters about surface subsidence as measuring standard was taken into accord,which contains the maximum subsidence of surface deformation,the maximum horizontal displacement,the maximum surface tilt,the maximum surface curvature deformation and the maximum surface level deformation.Conducting the comparative study on the above 5 parameters by probability integral method and field measured along the direction and tendency of observation line,and the effects of mining boundary angle was calculated.Referring to the relevant procedures of transmission line safety evaluation,we can judge the influence on high voltage transmission tower which made by 4~#coal mining subsidence and evaluate its safety.Based on the structural characteristics of transmission line,the surface subsidence of coal seam mining,horizontal displacement and tilt and other factors were analyzed to evaluate the effect of the operation of the power supply circuit and importance,it is stated that in the direction of power supply line and mining in parallel,vertical and oblique intersection,considering only the inclined,horizontal movement and vertical subsidence situation,numerical value of the specific parameters of the safe operation of the line,given the existence of integrated(horizontal,vertical)displacement,the impact of the safe operation of the mathematical formula,the intrinsic relationship between the surface subsidence and the safe operation of the power supply line and the matching of the layout is discussed,concluding that according to the coking coal working face layout and lining matching relations at present,4~#and 5~#coal using fully mechanized caving mining can guarantee the safe operation state of ground power supply line.According to the specific geological conditions and the choice of mining methods for coking coal mine,surface movement and deformation law of 4~#,8~#and 9~#coal seam mining was simulated by using FLAC 3D numerical simulation software.Comparison to the two predictive mode,this paper puts forward the development layout and mining(plate)area layout principle of the two coal mining in the lower part of the Jiao coal mine,the key technical parameters of mining layout was determined.Based on the optimization of the layout of the ground,tower protection effect was predicted.According to the location of the surface high pressure line and the geological conditions of the coal mine,a high voltage line passes through the working face layout is proposed,the working face is parallel to the high voltage line layout,three layout schemes for the layout of the working plane perpendicular to the high voltage lines.By comparing the three schemes of safety evaluation about high voltage power supply tower,it is concluded that the working surface is perpendicular to the high voltage line layout,high pressure tower is located in the center line of the working face corresponding to the top of the roadway in the middle of the three main lane,from the stop line at 50m,is the optimum project.It proposed the protection of high voltage power supply tower maintenance and preventive measures.In order to effectively control the influence of Datong coke coal mining activities on the surface of high voltage transmission tower and transmission line,combined with the specific geological conditions of the coking coal mine,it put forward the Datong coke coal mine multi-seam mining subsidence control mining method.It contains firstly using full mining full filling mining method of4#coal seam,then using a strip mining filling method mining 5~#coal seam.Based on the economic cost,ease of acquisition as well as the filling materials performance,the composition of raw materials and raw materials characteristics of coking coal mine filling materials were analyzed.In order to obtain the best ratio of raw materials,the orthogonal test of the three factors and three levels was adopt,the slump test was used to test working performance of filling slurry,the compressive strength of filling material at 3d,28d curing times was tested,designed and researched the filling system and equipment,the economic cost of each ratio was calculated and analyzed,through the use of FLAC 3D software to the numerical simulation to calculate and evaluate the stability and security of the tower,according to the safety of the tower specification mainly calculates the tower foundation uneven settlement.The inclination of transmission tower,and the transmission tower base of specific value,recommend using full mining full filling mining method to deal with the coke coal mining coal seams,as for5~#coal seam,uses strip filling mining method,the test group 5 is fit for the requirements of the safety,therefore the recommendation for filling materials proportioning is water:aggregate:cement=28?:65.4?:6.5?.Based on the research achievements,the evaluating the stability of stability high voltage transmission tower and putting forward the tower protection scheme,it provides an important theoretical and application guidance,and also has an extensive research value and far-reaching significance. |
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