Study On The Failure Of Assembled Wedges In The Of Complex And Jointed Rock Mass

The construction of road engineering in mountain areas often involves the evaluation of the stability of the cutting rock slope.In jointed rock mass,the failure mode of the cutting slope is mainly controlled by the rock mass structure,among the several modes,wedge-shaped failure is a main type.Based on the analysis of various failure modes of jointed rock slopes in the field,two typical assembled failure modes are proposed.The typical group failure mode in the field is related to the weak structural plane and joint characteristics.Firstly,the types and properties of the weak structural planes are studied,and the key weak interlayers,which influence the occurrence of wedge failure,are found out.Secondly,according to the lithology and strength,the characteristics of jointed and complex rock mass are studied.Finally,qualitative analysis and evaluation are carried out on the horizontal distribution of wedge failure in the sandstone mass with steep surface and vertical distribution in steeply inclined limestone mass.The main research results are as follows:(1)According to the engineering geological conditions of the slope in the study area,it is found that the slope in the hard rock stratum is characterized by jointed rock.The failure mode is different from other cutting rock slopes,which assembled wedge failure mode mainly include the horizontal and vertical distribution.(2)According to the type and properties of the weak structural surface,it is found that the weak interlayer of the primary silty mudstone has an important influence on the assembled wedge failure of horizontal distribution,and the weak and dissolve interlayer has a controlling effect on the assemble wedge failure of the vertical distribution.The other types of weak interbeds can also cause various failure modes of slopes,which affect the local stability of slopes.(3)According to the lithology and rock strength,the study on the cutting slope of the N-S road in Jurong city is carried out.For the assembled wedge failure of horizontal distribution,the joints provide multiple failure surfaces.For the assembled wedge failure along the vertical distribution of the dissolving weak intercalation,the joint to the slope provides a joint with long extension and penetration degree,which is easily eroded by the groundwater.Joint is also the main controlling factor for other failure modes.(4)The assembled wedge failure of the horizontal distribution in steeply dipping sandstone is related to the interaction between adjacent wedge-shaped bodies.The assembled wedge failure of the vertically distributed in steeply dipping limestone and the failure of the upper wedge-shaped body are related to the loading of the lower wedge-shaped body.