Study Of Mechanism Of Controlling The Overlying Rock By Injecting Ash Thick Liquid Into The Mining Collapse Zone

The surface subsidence caused by underground coal mining not only destroy the diggings environment and damage the surface buildings, but also go with serious hidden troubles. The root way of solving this problems is reasonable dispose the mine space. One technical approach is advanced about "Fly ash is injected into caving zone by high pressure controlling roof and overburden movement", and achieve the purpose about controlling roof and deformation of overburden movement, slowing surface subsidence , protecting surface buildings security.Aiming at these problems about the conformation of caving zone, slurry pervasion and the result of controlling roof must be solved. The character of caving zone at different depth, width and overburden structure, the flow regularities and pervasion radius about fly ash slurry in caving zone, the deformation characters about main roof and overburden before or after caving zone poured is analyzed by numerical simulation method.The thesis regards caving zone fragmentation rock which is poured as a "mixed rock". Establishing the constitutive equation, the calculation method of deformation quantity about whole "mixed rock" layer in the state of loading is given.Testing the "mixed rock" shaped by poured caving zone, and obtaining the connection between deformation and loaded pressure, the change of compactness in different pressure, the connection between deformation quantity and water-cement ratio of slurry about "mixed substance".Testing the different diameter fragmentation rock in caving zone, and obtaining the connection among deformation, porosity, expansion coefficient and the change of axially stress, and how to influence the grouting when these parameter changed is analyzed.The thesis draws into the plate theory after analyzing the rock structure of roof, and deducing the technology to calculate the curved of roof when the overlying rock is the thinner plate or the laminated rectangular plate.At last, the calculation of correlation parameter, idea of design, analysis of controlling results, evaluation of prediction effect about this technique project practice is given in HanDan Ming, and caving zone grouted is carried out can control the mining subsidence of main roof and overburden, slowdown the surface subsidence, protect the surface buildings security effectively though a example.