Study On Instability Mechanism And Support Technology Of Inclined Thin - Layer Rock Mass Roadway

In the nature,deposition rock with layered structure take up 2/3 of the land area,and the number reach to 77.3% in our country.The layred rack is more widely distributed in Yunnan and guizhou.Not only the distortion and strength of layered rock have anisotropy, the breakage mechanism also is different from other rock.This text,which is relied on the 860 pit 550 tunnel of YongChang lead zinc mine,do some research in the strength experiment of layered rock,include the field investigation,theoretical analysis,simulation experimenta and numerical simulation.Aiming at the instability mechanism of inclined thinly layered roadway surrounding rock to choice the supporting in reasonable and economically.Thus the efficient path for solving the problem is to create a better yield criterion and determine the strength parameter for rock strata.In this text,the main research are as follows:(1)Through the investigation of engineering geology and hydrogeology,the860pits 550 roadway,to understand the formation of lithology,geological structure and the lithology of surrounding rock. While to described the failure of layered surrounding rock.(2) To summary of current research on the failure menchanism of layered rock mass and the failure of layered rock mass roadway criterion.(3)Firstly, through the similarity theory study,transform the original simulation expeirment platform,to add the overburden pressure equipment. Secondly,to do the similar proportion expeiment.In the similar proportion expeiment,choice the in proportly simlar material in severe,comperssive strength,elastic modulus.(4)Though the similarity simulation expriment,analyzed the displacement variation rules with specific forms of roadway surrounding rock in the process of compression failure process, roadway, thus more intuitive display failure process of surrounding rock of roadwayinclined thin and determine the key position of destruction of roadway surrounding rock. Secondly, to used numerical simulation stress of roadway analysis the reasons of roadway losing.(5)For inclined layered rock tunnel instability mechanism specially, the length and short bolt conmbined support scheme is effectively.Resinged to verify the support scheme in numerical simulation, and on the basis the design of the length again anchor combined support scheme.