Simulation Research On Laws Of Ground Subsidence Caused By Goaf

Modern society demands more and more resources with it develops. Atthe same time, the disaster induced from the surface subsidence is becomingmore serious for the life of the people. Therefore, for the problems of surfacesubsidence induced from mining, we must strengthen the research on theregularity of ground settlement caused by goaf. It will have very hightheoretical significance and practical valve.In this paper, for the Fuyang coal mining of Jiaohe city in Jilin province, byusing the numerical method, we have done reasonable numerical simulation.In the end, we would do some description of ground subsidence distributioncharacteristics from the result of the ground deformation.In the meanwhile, wecould make some analysis of surface settlement and provide reasonablereferences for any related project on ground surface.So, we should not only know the regularity of surface deformation fromcoal excavation, but also need have thorough understanding about effects ofsome main factors on surface deformation. Only in this way, we could betterpredict surface deformation for goaf under different conditions. There are a lotof factors making influence on the surface deformation for goaf. In this paper,we choose some main influence factors on goaf to study. These factors are asfollows: the mechanical properties and horizon of overburden rock, the miningdepth, the mining thickness, the depth/thickness ratio and the dip angle of coalseam. With the help of FLAC3D software, designing the ideal model, choosingMoore-coulomb Model, we made a single analysis for each of these factors.Some laws of ground deformation we got are as follows:(1)The strata of layers refer to the relationship of the rock. The strata oflayers have a great influence on the rock deformation and ground subsidence. The combination of different layers will product different effect of groundsettlement. So, if other conditions are of the same, the value of surfacesubsidence caused by goaf which is covered by soft layers will be bigger thanthe goaf covered by hard layers.(2)With the increase of the dip angle of coal seam, the displacementisoline of surface subsidence became asymmetric and the displacement inuphill direction was reducing gradually. The maximum displacement of surfacesubsidence bias downhill was happening. Also, the area of negative horizontaldisplacement and the maximum negative horizontal displacement decreased.(3) For a fixed thickness of coal seam goaf, with the mining depth of goafincreases, that is, with the depth/thickness ratio increases, horizontal andvertical displacement of the earth’s surface are gradually reduced. The deeperof the goaf, the influence of the goaf on the earth’ surface will became smaller.For a fixed depth of coal seam goaf, with the mining thickness of goafincreases, that is, with the depth/thickness ratio decreases, horizontal andvertical displacement of the earth’s surface were gradually increased. For themining depth and mining thickness are all different, but the samedepth/thickness ratio, with the depth and thickness increases of the goaf, theground deformation is gently increased, which showing that the influence ofthe mining thickness on the deformation of the surface is slightly larger thanthe mining depth.By mastering these laws, it will be of great significance for us to preventand reduce the geological disasters caused by the goaf subsidence.