Study On Floor Heave Control Of Western Diggings Weakly Cemented Soft Rock Roadway

In western mining area often encountered low intensity,poor cementation, argillationwhen encounter water, called weakly cemented soft rock. Traditional support ways are unableto keep its stability.Floor heave is one of the most obvious damage types.In Inner Mongolia New Shanghai No.1Temple Coal Mine112052crossheadingsurround rock has typical characteristics of weakly cemented soft rock, floor rock isdisintegration when encount water, serious clay and floor heave seriously. paper through theanalysis of surround rock’s mechanical properties and water-physical properties, based on thephysical simulation, FLAC3Dnumerical simulation and combining field measurement, aim atfloor failure mechanism, impact factors, mechanism of grid continuous wall with groutingcable anchor supporting scheme, had been discussed deeply and systemically. The mainresearch contents and conclusions were as follows:（1）Through determination of rock sample’s physical and mechanical properties fromthe field, learn that strength of rock is below20MPa, through X-ray Diffraction analys themineral composition of floor mudstone, learn that floor rock contains kaolinite, illite, illitesmectite mixed layer, etc. Contrastive analysis with rock strength and rock cohesion ofcentral-eastern mining districts, learn that112052crossheading surround rock’s uniaxialcompressive strength and cohesion of rock is much less than rock strength of central-easternmining districts.（2）Through physical simulation, the surrounding rock deformation and fractureevolution law under3kinds of supporting structure: non supporting, anchorage supporting ofroof and two sides（non supporting of floor）, grid continue wall, learn that the floor is shearslide destroy, build mechanical model of shear slide floor heave, then design the grid continuewall supporting parameters. In the end, through comprehensive analysis of surround rock’sfailure law under3kinds of supporting structure（3）Through FLAC3Dnumerical simulation, learn that under different supportingconditions,the deformation of floor and plastic zone scope didn’t appear to be much different,under support pattern of grid continue wall, the deformation of floor and plastic zone scopedecreased significantly, under grid continue wall combine grouting cable anchor, thedeformation of floor and plastic zone scope decreased significantly more, indicate that thedeformation of floor is effective controled, when roadway is under different lateral pressurecoefficients, along with the increase of lateral pressure coefficients, the deformation of floor and plastic zone scope iecreased significantly, when road is under hard rock, compared withthe original rock conditions, the deformation of floor decreased50%~80%, and the plasticzone scope decreased significantly, illustrate that the deformation of floor and plastic zonescope is impacted easily by lateral pressure coefficients and floor lithology.（4）This research carried out the industrial test of grid continue wall combine groutingcable anchor of New Shanghai No.1Temple Coal Mine112052crossheading. And it provedthe supporting technology can effectively maintain weakly cemented soft rock crossheadingin the stability of the service period.