Study On Losing Stability Mechanism Of Flare Rock Slopes

At present,there are already a lot of fruits in research on stability of consequent rock slope. By far,the analysis model and the analysis method both aim at this type of slope.But the reverse slope which typical structure characteristic is the strata bedding surface and slope strike the same but the opposite tendency,at the same time if there are one or more positive slope direction joints which will cut rock layer to discrete blocks,it is more prone to tilting failure which is different from anciently.For such antidip layered rock slope,the system study of its failure mode and mechanical have never be reported up to today.Therefore,this paper use a large geotechnical engineering simulation analysis system FINAL which introduce from Austria as a platform,establish several typical antidip layered rock slope model.Through special discrete finite element model and test of numerical value,the slope tilting failure mechanical and mode are studied,and directly provide reference to engineering design.Main conclusions are as follows:(1)Systemic study the main factors that impact antidip layered rock slope,make some discussion about the mechanical model of the structure surface,and determine the structure surface strength parameters under considering connectivity conditions,then through discretization finite element analysis method to study the main failure mode of the reverse layered rock slope(tilting failure and shear slip).(2)the factors such as the mechanical characteristics of structure surface and rock mass, and some physical geometry characteristics of slope that impact stability of the type slope are analyzed.①The results showed that antidip layered slope to a more obvious dip characteristics, the general inclination to rock more than 45°,slope excavation slope angle is greater than 55°;②rock from the thickness of 2 m to 4 m,the predominant rock inclination of this class slope dip deformation up to 60°;③structure parameters on the dip destruction of their control,classⅣrock perform bending tilting failure,while classⅢrock mainly perform brittle fracture damage;④trailing edge with a joint surface and the inclination angle less than 30°,the failure mode of such antidip layered slope tend to tilting failure,when the inclination angle more than 45°,such antidip slope mainly show dip-slip combination failure mode;⑤as for the weak base of bottom slope,when the rock angle greater than 45°,with the weak base thickened,weak base opening between the upper slate increase.The opening to the slope surface increase more,show that such slope prone to compression tilting failure.(3)Application of the above analysis results against such slope,propose rational stability analysis and evaluation method:through building a relationship curve of the deformation,stress and the sliding surface safety factor after slope excavation,comprehensive analysis the antidip slope failure mode.(4)through above analysis,use the discretization finite element analysis method to the left bank abutment reverse slope of Jinping-1 hydropower station,qualitative analysis of the major slope failure mode for specific projects to provide guidance.