Numerical Simulation Of Instability Subgrade In Goaf And Karst Area

In the central and west regions of our country, there is distributed a large number of karst cavity; At the same time ,these are abundant mineral resources under ground in these regions, because of its long history mining, the goaf cavities are distributed widely. With the "development of western regions"implementation and the development of urban construction in goaf-karst cavity areas, highways will come from or pass through these areas, We will face many questions of instability subgrade which caused by goaf-karst cavity collapse. This thesis have some research on subgrade stability of two engineers in goaf-karst cavity areas. Firstly, author summarize the influence factor of subgrade stability and general treatment after goaf-karst cavity collapsed, then analyse the stability of subgrade lie concealed a goaf or karst cavity using finite element method, lastly put forward some useful advice and settlement for the engineer construction . The engineer analyse of subgrade stability caused by mining is relied on a project of PingShuo Coal Mining in ShanXi. I selected a typical section to make a series of study, got the deformation trend and evolution regulation of subgrade from model experiment after the coal was mined which lie concealed in the subgrade, made evaluation with ration about influence of mining under subgrade using FLAC soft such as confirming the "ARC-BED"slide model and slip scope, calculated the F.S. of subgrade slope used limit equilibrium theory, and advance particular measure for the PingShuo Coal Mining Company.The engineer analyse of subgrade stability caused by karst cavity was relied on a collapse accident happened in ChangJin expressway. I obtained the suitable parameter of rock and soil through the numerical simulation of collapse subgrade, evaluated the treatment project to the subgrade near collapse by using the parameter which get in frontal calculation, and choosed a better project through the result of numerical simulation. Finally the thesis has been summarized the measure that we should take in the design and construction when we encounter the same question during the highway construction, which is important for us to construct a highway in goaf-karst cavity area.