Research On Stability Of Carbonaceous Shale Cutting Slope With Weak Interlayer Based On Centrifugal Model Test

Based on the National Natural Science Fund(No.51374042)in Guangxi,Liuzhou to Nanning Expressway Extension Project of the carbonaceous shale slope as the research object,adopting the research method of centrifugal model test and numerical analysis are combined,the slope stability research of carbonaceous shale cutting out with weak interlayer,the main results were as follows:(1)With the increase of centrifugal acceleration,vertical displacement with weak interlayer carbonaceous shale slope slope has significantly increased,the overall change of vertical displacement of slope monitoring points showed the same trend,ladder shaped.In the centrifuge acceleration increased from 0g to 30g,the horizontal displacement with weak interlayer carbonaceous shale slope increases;when the centrifugal acceleration is stable at 30g,horizontal displacement of slope is not obvious;with the increase of centrifugal acceleration to reach 60g in the process of horizontal displacement of slope is also increased,when the acceleration reaches 60g slope monitoring points,horizontal displacement mutation can be judged in the acceleration reaches 60g,with weak interlayer carbonaceous shale slope slip instability,the slope monitoring points of displacement mutation phenomenon.(2)The deformation and failure mode by strength reduction by carbon shale slope,when the soft interlayer does not contain carbonaceous shale in the cutting slope,slope slip rifting occurs when damage;carbonaceous shale slope with weak interlayer inclination,inclined interlayer above experience along the direction of slope sandwich block sliding failure.But after the slope formation of interlayer inclined arc when landslide;carbonaceous shale slope with weak interlayer level,weak interlayer slope along the horizontal flat push sliding failure;when the carbonaceous shale slope contains two kinds(tilt and horizontal)weak interlayer,inclined sandwich block slip area is above,and the level of the soft interlayer and inclined slope soft interlayer between flat push type slip.(3)The plastic zone distribution,the maximum horizontal displacement and the safety factor of the cutting slope of the carbonaceous shale are obviously influenced by the cohesive force of the weak intercalation and the internal friction.With weak interlayer cohesion and internal friction angle decreased gradually,the carbonaceous shale slope distribution of plastic zone is more and more obvious,also expanded the scope of the maximum horizontal displacement of the carbonaceous shale slope place is changed by the level began to appear in the vicinity of weak interlayer gradually transforming to tilt the weak layer,and the maximum the value of horizontal displacement is increased obviously,the safety coefficient of the carbonaceous shale slope significantly decreased.