Study On The Instability Mechanism Of Bedding Rock Slope With Two Groups Of Crossover Structures

Rock slope instability,as a kind of common disaster with high frequency,has been paid great attention by people.CoMPared with other types of rock slopes,the type of bedding rock slope has the worst stability and is most prone to deformation and failure.In addition,the stability of the slope will be greatly reduced and the rock mass will be excessively deformed and destroyed when two groups of crossover gently inclined and steep inclined structural planes dipping outside slope are developed in the bedding rock slope.Once the slope is unstable,it will lead to serious loss of life and property to the residents in the surrounding area.Therefore,it is of great significance to study the failure mechanism of the bedding rock slope with two groups of crossover structural planes in order to protect people's life and property.In this paper,the failure mechanism of this kind of slope had been studied in aspect of theoretical analysis,numerical simulation and engineering application from point of the view of the present research situation and practical the problems existing in practice,as follows:(1)The geomechanical geometric model of this type of slope had been established,and its stability development law under the different spatial geometric combinations and the different mechanical parameter combinations of two groups of crossover structural planes had been analyzed by using limit equilibrium method.Finally,with the help of orthogonal design test,the sensitivity and predominant factors of slope instability under these two classes of combination had been obtained.(2)The numerical simulation had been carried out by the discrete element software(UDEC)to study the instability mechanism of the bedding rock slope with two groups of crossover structural planes.It revealed the Specific failure mode of the slope under different space combinations of structural planes and different mechanical parameter combinations.When crossover structural planes have different spatial geometric combinations,The specific failure modes of the slope under instability are different,mainly the compression shear failure with single sliding surface and the compression shear crack failure with double sliding surface.The failure mode of slope instability under different mechanical parameters is the compression shear crack failure with double sliding surface.(3)The west slope of Datong Hanguang Granite Mine in Shanxi Province is a typical bedding rock slope with two groups of crossover structural planes.According to engineering geology and hydrogeological conditions,Several failure modes of potential instability of this slope had been preliminarily analyzed.Further,through numerical simulation,it had been concluded that the failure mode of potential instability of this slope is the compression shear crack failure with double sliding surface,which is consistent with the failure mode proposed in this paper.