Study On The Characteristics Of Surface Movement And Deformation And Railway Safety In The Hilly Area Of Daning Coal Mine

The laws of surface movement caused by underground mining in hilly areas were different from that of generally flat terrain.According to the geological conditions of the 108 mining face in Daning Coal Mine of Shanxi Province,the characteristics of surface movement and deformation of coal mining in hilly area and its effect on railway construction were analyzed by collecting and analyzing the measured data,FLAC^3D numerical simulation and simulation experiments.The movement and deformation of railway under different mining schemes were analyzed,and the optimal mining scheme was selected to protect the railway.According to the analysis of the measured data from the surface movement observation station of the 108 working face in Daning coal mine,the characteristics of the surface movement and deformation of the well mining in the hilly area were obtained.The results showed that:coal mining on the hilly areas,the surface subsidence basin was inclined down the slope along the slope body,the tangent of major influence angle and deviation of inflection point were increased in the uphill direction and decreased in the downhill direction;in the slope part,the horizontal deformation value was increased in the upslope direction,decreased in the slope direction,and the surface was in the tensile state;while in the center and the outer side of the basin,the horizontal deformation was similar to the flat land,and the surface was in compression state.The 3D model was built by FLAC3D,and the scene was verified.The influence of coal mining on Railway movement and deformation in hilly area was further studied.According to"Railway Technology Management Regulations",safety evaluation of Daning coal mine dedicated railway line was carried out;the influence of different mining width and width on the movement of railway was studied in view of the mining scheme.The results showed that:the FLAC3D numerical simulation method can be effectively applied to the prediction surface movement and deformation of hilly land;the current mining plan can ensure the normal operation of the railway;the limitation of mining plan from two aspects of height and width can achieve the purpose of protecting railway.According to the simulation experiments,it could be concluded that:with the increase of face width,the stress balance arch formed in the upper part of goaf was continuously moved upward to the direction of increasing width and disappeared after that reached the surface loess layer.In this process,the stress balance arch was played an important role in controlling surface deformation.With the increase of mining width,the subsidence value of the surface railway line was increased,and the horizontal direction was firstly moved along the mountain body toward the downhill direction,and then moved to the direction of the goaf due to the mining influence.