Identification Program Of Key Stratum And The Grouting Slurry Ratio Test In The Method Of Isolated Overburden Grout Injection In A Working Face Of Wuyang Coal Mine

Isolated overburden grout injection technology makes use of the separated tearing space caused by the uncoordinated deformation of upper strata in the process of coal mining.This newly developed subsidence control technology through drilling the surface to the depth of the separation space for filling controls the surface settlement.First applied in Poland in 1986,this technology was introduced and popularized in Fushun,Datun,Huafeng,Yanzhou and other mining areas in China,which significantly reduced the surface subsidence.But at present,there are still some problems in the Isolated overburden grout injection technology,such as where to grouting and what kind of grouting,that is,the identification of key Stratum and the characteristics of grouting slurryTherefore,this paper is based on the "Wuyang Coal Mine Solid Waste Disposal and Collapse Control Project" carried out by China National Administration of Coal Geology at the working face of NO.8006 in Wuyang Coal Mine.The key stratum identification program is compiled by MATLAB language according to the principle of key stratum.The results are verified and applied to practical engineering cases.The reasonable determination of grouting layer is discussed.According to review,the grouting material,slurry variables and evaluation indexes are selected,and the influencing factors,main parameters,control indexes and scope of slurry ratio are obtained.Based on orthogonal test results,the rule of multi factor slurry test and main factors of slurry properties are analyzed by statistical principle.The single factor test is carried out to further explore the influence of water-solid ratio on slurry properties.The results and conclusions are as follows.(1)The running results of the key stratum identification program based on MATLAB language solves the problem of grouting layer and consistent with those in the literature of experts,which proves that the program identification is correct.The practical engineering test shows that the program has a certain practical application value.(2)Through the method of orthogonal test,the properties of grouting composite grouting material are grasped,and the problem of grouting slurry characteristics is improved.The influence of water-solid ratio on each factor is particularly significant.By adjusting the water-solid ratio,the properties of slurry can be changed to a great extent.According to the actual situation of the project,selecting the appropriate proportion of additive can improve the properties of the slurry in a certain range.The comparison of single factor and multi factor results shows that the conclusion of the slurry ratio test is reliable.(3)According to the project situation of 8006 working face,the key layer program is applied to the engineering practice,and the key stratum of 8006 working face of Wuyang Coal Mine is identified and grouting layer is selected.Grouting materials and their proportion are selected according to the engineering characteristics.