Research On Structure Parameter Of The Underground Of Transition From Open Pit To Underground Mine On Shirengou Mine

There are many experience about the study and optimization of the underground stopestructure parameters of domestic and foreign mines, but experience about the mine duringtransition from open pit to underground are lesser.Through comprehensively realizing the characters of mines during the transition fromopen pit to underground mine, the key elements have been defined that influence structureparameter of mines during transition. By means of comment on the methods of definingthe structure parameters of the stope, numerical simulation method has been selected.Based on the analysis of engineering geology and current situation of Shirengou ironmine, the rock mechanical parameters have been measured, and the rock mass parametershave been further obtained through properly weakening. In addition, the time-effect of rockmass intension and weakening of water have been also considered, thus making theparameters more reasonable.Because of the difference of the northern area's geology condition of Shirengou ironmine, subsection modeling has been adopted. Finite Element Numerical Modeling is set upbetween line12 to 18(Area I), and so do Finite Difference Modeling between line 6 to12(Area II) and in the north of line 6(Area III). Nine kinds of project are utilized in everysubsection. Distribution of stress and strain of side and slope are obtained to judge thestability.In addition to the data obtained about the stress and strain of the slope and stope,development ratio, index of economic benefit, is also introduced in the ComprehensiveFuzzy Mathematics Modeling. This model has been established considering safety andprofit by use of fuzzy theory. Through the comprehensive evaluation, the finest project hasbeen acquired , and accordingly structure parameter of room has been acquired:Area I: length of room 50m, height of room 44m, spacer pillar 10m, top pillar 5m,floor pillar 12m;Area II: length of room 50m, height of room 44m, spacer pillar 10m, top pillar 5m,floor pillar 12m;Area III: length of room 50m, height of room 44m, spacer pillar 12m, top pillar 5m,floor pillar 12m.There is a certain exploring meaning to the study of the stability of the high, cliffyslope under the underground mining.