Regularity Research Of Goaf Grouting Diffusion Of Yang-Yi Freeway

Based on the engineering geological properties of underlying goafs of Yang-Yi freeway,taking the grouting treatment project as the project background, this paper calculated theresidual deformation along the goafs and analyzed their stability with the method ofprobability integral. Using theoretical analysis, the goaf can be divided into three differentforms of geological accumulation area: hollow or roadway and coal pillars and rock fall.Theratio of cement fly-ash grout experiment was designed by orthogonal method, which obtainedthe relevant ratio optimization scheme.Numerical simulation software FLAC3Dwas used toestablish the typical simplified model goaf, respectively to simulate the slurry in the cavityand the free diffusion in the drift, the splitting grouting process in coal pillar and deposit inrock and soil cave and the penetration grouting process. The following conclusions can beobtained through the above research:(1) the coal goaf residual deformation do not conform to the requirements of the highwayrelated specification. In order to guarantee the safety of the freeway construction andoperation, corresponding control measures should be taking for goafs. Through thecoMParison and analysis of goaf management scheme, this paper selected the full fillingpressure grouting method to control coal mine goaf.(2) the ratio results of fly ash gr and cement grouting test shows that the ratio betweenwater and cement in meet the requirements of slurry filling range as small as possible, thecement of solid-phase mass fraction in the test range is more than20%, the curing period of28days. Ratio of a single scheme of optimizing conditions for: water solid ratio of1:1.5, thecement of solid-phase mass fraction was30%, the curing period of28days.(3) Combined with grouting theory and the numerical simulation,the results shows thatthe slurry in the roadway in the goaf cavity and filling in the form of the free diffusion, mainly by infiltrators in the loose body filling, filling in splitting way in coal pillar. Among them, thesplitting grouting, grouting pressure, grouting penetration diffusion of freedom and thegrouting pressure is smaller. Grouting makes the physical and mechanical properties of rockand soil layer has improved greatly, its resistance to deformation ability was greatly enhanced.