Research On Surface Subsidence Characteristics In Sihe Coal Mine And Optimum Design Of Protective Coal Pillar For Ultra High Voltage Transmission Line Tower

Surface subsidence induced by the coal mine underground mining causes damage to surface buildings and structures. The “Southeast of Jin—Nanyang —Jingmen”1000KV Ultra High Voltage Transmission Line experiment demonstration project which constructed in our country for the first time steps across Jincheng Anthracite Mining Group Sihe Coal Mine.The investment of the project is vast and the significance to the national economy is profound. The mining affected areas of Shanxi section—Sihe coal mine is selected as research objection in this thesis,in which the surface subsidence characteristics of Sihe Coal Mine and optimum design of protective coal pillar for Ultra High Voltage Transmission Line Tower is studied by using the field measurement,the numerical simulation and so on.First, based on the geological and mining conditions of Sihe coal mine, it was established the observation station to measure the surface subsidence and the effects of high voltage line towers caused by excavation of working face. The angel parameters of strata movement were got by calculating depends on measured data. According to the field measurement and theoretical analysis, it was got the angle parameters of Sihe mine under repeated mining.And the optimum size of high voltage tower protective coal pillar was designed by the vertical method. Finally, the anticipation of surface movement and deformation was made by probability integral method after 1308 working face extraction. The mining impact assessment of high voltage line towers was made based on the expected results and mining technical measures and protection of high voltage line towers technical measures were put forward; based on the N155 high voltage line tower of 1308 working face, numerical model was set up to study the effect of different mining face length on high voltage transmission line tower with FLAC3 D.The best scheme was obtained when the mining length of 1308 working face was150 m.This study provides important basis for the high voltage tower protection and has certain instructional significance to improve the recovery rate of coal resources, reduce the mining damage and protect the surface buildings and structures.