Stability Analysis Of Rocky High Slope Controlled By Two Groups Of Structural Planes

Mining-induced instability and failure of rock slopes have received more attentions.Since structural planes adversely affect the stability of rock slope,two groups of staggered outward structural planes with steep and gentle dips make the instability of slope more easily occur,which poses a great threat to the security of lives and properties.Consequently,it is significant to study the stability of high rock slopes with two structural planes.Based on the current researches of slopes and engineering background,the instability rules and failure mechanisms of high rock slopes inclined two groups of structural planes have been conducted by theoretical analysis and limit equilibrium calculation and put into engineering application,the relevant conclusions are as follows:(1)Through the review of relevant literatures,the analysis methods and instability classifications of high rock slopes have been summarized.We propose the failure modes of high rock slopes inclined two groups of structural planes and find their main influenced factors linking practical projects.(2)Basd on the actual engineering background,a geomechanical model has been established.Slide software has been used to calculate the security coefficient of slopes under different spatial combinations of the two sets of structural planes(Combination of slowly inclined structural plane ? with steep structural plane ? and potential sliding body thickness D of slope).Accordingly,we analyze the rules between the mechanical parameters of rock mass and the security coefficient of slopes by limit equilibrium method(Combination of internal friction angle ? with cohesion C of mechanical parameters of structural plane and potential sliding body thickness D of slope).(3)The results of the limit equilibrium analysis indicate that security coefficient Decreases firstly and then increases as the thickness of slide body increases,which can be divided into two stages and shows U shape under different spatial combination of ? and ?.(4)Under different spatial combinations of ? and D,the slope security coefficient F decreases as the angle of structural plane ? increases,the variation rules can be divided into two types related to different thicknesses of slide body D.(5)Under a certain mechanical parameters of structural planes C and ?,the slope security coefficient first decreases sharply and then increases slowly as the thickness of slide body increases.The slope security coefficient is larger as ? is higher when C is constant.Additionally,the slope security coefficient is larger as C is larger under a certain value of d and ?.(6)The North China Granite Mine is a typical rocky high slope interlaced two groups of structural planes.According to engineering geological survey and indoor test results,the failure mode of the slope has been ascertained by analyzing several potential failure characteristics.Slope security coefficient was calculated by limit equilibrium method,and the sliding range of slope was found based on stability analysis.