Experimental Study On The Law Of Slurry Packing In Goaf

The grouting method is a kind of control measures of the mined out area with low cost and good effect, It has been widely used and popularized in the filling of large cavity goaf. The accumulation form of slurry is an important basis for the distance of the drill hole and the proportion of the slurry. But the research results in this field are still not perfect,This causes the distribution of the hole and the ratio of the slurry is usually designed and carried out according to the previous construction experience, The lack of this kind of theory is bound to cause blindness in practice. Therefore, it is of great theoretical significance and practical value to study the accumulation law of slurry in the goaf. Taking this as a starting point, this paper uses the laboratory model test, the field simulation test, and combined with the engineering case to study the accumulation law of slurry.Firstly,This paper adopts the RST-CC paddle type rheometer to test the rheology of slurry, it is found that the relationship between shear stress and shear rate should be in accord with characteristic of Bingham fluid; The regression analysis of the rheological curves of the test groups showed that the yield stress and plastic viscosity of the slurry increased slowly with the increase of sand content rate, When the sand rate increases to a certain extent, the slurry yield stress and plastic viscosity exponentially increase, namely, the existence of a certain "inflection point" sand ratio. Under the experimental conditions, the "inflection point" sand content rate approximation is 45%. This value can be regade as a control parameter to sand content rate.Secondly, Based on the laboratory model experiment and the results of laboratory test, the theoretical calculation formula of self flow accumulation slope is established, which is suitable for the aggregate distribution of aeolian sand:θ=0.175×σ00.572μ0.206ρ(ρ≤1.936g/cm3)。Thirdly, Based on the accumulate experiment, the results shows that the theoretical calculation method based on the self gravity accumulation model has high accuracy; And through the research and Analysis on the change of the shape and the size of the aggregate particles sort to visualize the process of accumulate.Finally, Through the engineering case, the theoretical calculation method of slurry accumulate shape was further verified...