HSSPC Method And Its Application In The Stability Evaluation Of Hydraulic High And Steep Rock Slopes

In recent years,with the rapid development of China's economy,the country's demand for energy continues to expand,and mineral resources are increasingly depleted,prompting the development of hydropower resources.The unprecedented development of the hydropower business has created a large number of world-class mega projects while also hiding the potential risk of slope instability.As we all know,the slope of hydropower engineering has the characteristics of large slope height,complex geological structure and environmental conditions,which often leads to greater difficulty in site investigation and data acquisition,high risk,and difficult slope stability evaluation.However,hydropower engineering is different from other industries in that its engineering is of high grade and high importance.It requires high stability of temporary slopes and permanent slopes,which often requires quick and accurate prediction by the project builders.Based on on-site geological survey,this paper uses engineering geological analysis,Geo Studio limit equilibrium,ABAQUS numerical simulation,and HSSPC method as research methods to gradually carry out rock slope stability evaluation in the Busigou hydropower project pivot area.This article mainly draws the following conclusions:(1)According to on-site geological survey,the lithology of the strata in the hub area is metamorphic sandstone and slate in the Upper Triassic Zagunao Formation(T₃z)and Triassic Upper Jujuo Formation(T₃zh);Extrusion fracture zone,small faults,joint fissures;the physical and geological phenomena of the slope are mainly weathering,unloading,collapse,and accumulation;the permeability of the bedrock in the river bed valley and the bank slopes on both banks is weak,and the permeability is q=(1?10)Lu.(2)According to the engineering geological classification of the slope,the structural characteristics of the rock mass,the division of the weathering unloading zone,the quality classification of the rock mass,and the value of the mechanical parameters,the rock mass structure of the slope is a layered structure,mainly developed in grades?,?,and?Structural plane;weathered unloading zone is divided into weakly weathered strong,weak,no unloading zone,slightly weathered?fresh rock zone;slope rock mass quality is grade III,shallow surface rock mass quality is grade IV,internal rock mass of slope The quality is grade II;the comprehensive value of the mechanical parameters of the slope rock mass is basically consistent with the recommended value of the power station pre-reportable report,and is slightly larger than the recommended value.(3)According to the analysis of the deformation and failure phenomena and the failure mode of the slope,the deformation and failure phenomena and the failure modes of the rock slope in the hub area are summarized as follows:broken rock?solitary rock roll-off flow failure,dumping?slip failure,compound failure.(4)Based on engineering geological analysis,a preliminary evaluation of the stability of the power station slope is made.The results show that:the inlet slope(hole face,side slope),the left bank slope of the ground plant valley,the slope is basically stable,and the shallow surface is prone Instability;the abutment slope on the right bank(dam shoulder,toe plate)and the slope behind the ground plant are generally stable.(5)Based on Geo Studio limit equilibrium calculation,with different weathering unloading zones as the division,three working conditions and three methods are selected to calculate the slope stability coefficient and predict the slope stability.The results show that the slope is basically stable,Shallow surface is prone to instability.(6)Based on the ABAQUS numerical simulation,considering the self-weight stress field,the displacement and stress characteristics analysis is carried out.The results show that the slope is basically stable,and the shallow surface is prone to instability.(7)Based on the SSPC research results of the Dutch scholar R.Hack,from the perspectives of selection of structural planes for evaluation,optimization of evaluation indicators,and value selection,statistically superior structural planes and geologically superior structural planes are included in the selection of structural planes for evaluation,based on indoor rock The physical and mechanical properties test,the number of cracks in the 5m tunnel section are used to optimize the compressive strength of the complete rock IRS and the degree of weathering WE,and the shear strength c,?,maximum SSPC correction of slope height Hmax,proposed the SSPC method(HSSPC method)for hydropower engineering based on geological exploration data,and applied it to the slope stability evaluation of Busigou Hydropower Station.The evaluation results show that:HSSPC can be better applied Evaluation and prediction of the stability of rock slopes in the hydropower project hub area.(8)For the rock slopes in the hub area,engineering geological analysis,Geo Studio limit equilibrium,ABAQUS numerical simulation,and HSSPC method are used as research methods,and the stability evaluation and prediction of the power plant slope are carried out in turn.The analysis,Geo Studio limit equilibrium,and ABAQUS numerical simulation results are basically consistent,indicating that HSSPC can be well applied to the evaluation of high steep rock slope stability in hydropower projects.