The Grey Correlation Analysis On The Parameters Of The Strip Filling Bands In The Backfill Filling Mining

Filling mining technology is one of the mining technologies that using the fillingmaterials by filling machine and equipment to fill the mined out area after mining the coal andbefore the roof falls. In recent years filling mining becomes a very popular way to exploit thecoal that is the “three underground coal” because the filling material is generally using coalgangue, fly ash and cement, they are cheap and easy to get.Through the tries of some mines,filling mining has been proved that it can boost the recycling rate and can use some rubbish ofthe coal mine.Strip filling mining technology belongs to the technology of a partial backfill mining, itis to fill part of the mined out area after mining the coal and before the roof falls, to composediscontinuous filling bands to support the overlying strata. Compared to the whole fillingmining technology, strip filling mining technology can reduce the amount of the filling bands,and lower production costs. Because strip filling is one of the partial backfill mining, so thewidth and distance of strip filling are very important to the effect of the filling mining, andthey can affect the surface subsidence.This paper is based on the geological date of Caocun Coal Mine, tests the relativephysical and mechanical parameters of the rocks by experiments in the laboratory. Then usingthe “key strata” theory to calculate which strata is the “key strata”, and then according to thekey strata and the relative knowledge of breaking away distance to decide the interval of the filling bands. The parameters that affect the surface subsidence not only contain the intervalof the filling bands, but also contain the width, the bulk modulus, the shear modulus, thedensity, the angles of internal friction, the cohesive force and tensile strength. The paperanalyses the influence factors except the interval of strip filling mining with the Greycorrelation theory, and rank the influence factors according to the relative coefficient, then wecan know that the bulk modulus, the density and the width can affect the surface subsidencetempestuously, and we can take further study of these factors to guide the actual production.This paper simulates the relative situation of the strip filling mining with the FLACnumerical simulation software. According to the result of the simulation, it analyses thesubsidence, the horizontal movement, the bias value, the horizontal deformation and thecurvature of the surface, we can know that in the specific geological conditions of the CaocunCoal Mine, the parameters of the strip filling bands can refer to the followings: the bulkmodulus should not be less than2.34GPa, the density should not be less than2000kg/m3,reasonable width of filling strip is35m。...