Application Of Slope Acceleration Method In Slope Stability Analysis

The slope is not only a geological environment,but also an important part of people's engineering development and construction.China suffers from the landslide hazard every year,and the direct economic loss caused by the instability and slippage of the slope is achieved about 20 billion yuan every year.Accurately evaluating the stability of a slope and taking necessary measures according to the scale of the disaster it may cause is an important means to prevent landslide accidents and ensure the safety of people's property and engineering safety.Therefore,this paper proposes a new method to analyze slope stability—the slope acceleration method,and systematically studies its accuracy,rationality and applicability.The main research contents are:Firstly,the commonly used slope stability analysis methods,including limit analysis method and finite element method,are reviewed.The basic principles of each method are expounded.At the same time,the advantages and disadvantages of each method are analyzed briefly.The slope acceleration method used to analyze the slope stability is derived based on the limit equilibrium principle.The generalized Mises criterion and the Mohr-Coulomb yield criterion commonly used in numerical simulation are summarized.At the same time,the parameter expressions corresponding to the Drunker-Prager criteria are derived for the different values of the Lode angle.Secondly,using the slope acceleration method and starting from the homogeneous soil slope,the calculation results of the safety factor and the plastic zone are compared with the limit equilibrium method and the finite element strength reduction method.Based on the Morgenstern-Price method in the limit equilibrium method,the error analysis of the safety factor is carried out to determine the accuracy of the calculation of the method.The gray correlation analysis method is used to compare the soil weight,soil strength,elastic modulus and Poisson's ratio.Sensitivity analysis is carried out for factors affecting the safety factor.Further,the non-homogeneous slope,three-dimensional slope and anti-slide pile reinforcement slope are analyzed,and the application range of the method is further broadened to study its stability in slope.Thirdly,taking a specific project in Ya'an City of Sichuan Province as an example,the slope acceleration method is used to analyze the stability of the slope,and the effect of slope reinforcement is studied.Research shows:Firstly,compared with the limit equilibrium method,the slope acceleration method cantruly reflect the mechanism of slope failure.The principle is simple,the physical meaning is clear,and it can reflect the dynamic process of slope failure.It is suitable for a wider range and more suitable for slope,and more in line with the actual destruction behavior of the slope.Secondly,the slope acceleration method proposed in this paper applies the acceleration along the slope direction to the slope by incremental loading to make the slope in the limit state.It is not necessary to reduce the strength parameters of the soil and avoid choosing the reduction factor.It is in line with the actual landslide mechanism of the project.It can be applied to the wide slope angle range from gentle slope to steep slope,and overcomes the shortcomings of the Gravity increaseing method;it can be applied to the stability analysis of heterogeneous slope and overcome the shortcomings of the slope-centrifugation method.At the same time,the calculation results and the Morgenstern-Price method in the limit equilibrium method are kept within 5% of the error,which can meet the requirements of the project.Thirdly,the parameter sensitivity analysis of the slope acceleration method shows that the influence of each factor on the safety factor is: cohesion > internal friction angle > slope angle > soil weight,cohesion and internal friction angle are still the main factor,elastic modulus and Poisson's ratio have no effect,which is consistent with the general law;the analysis of DP series criteria shows that the calculation results of DP2 and DP5 criteria are reasonable;three-dimensional slope stability shows that the calculation result of the slope acceleration method is similar to the strength reduction method,and it still has applicability in the three-dimensional slope.Fourthly,in the reinforcement project of the left bank slope of a reservoir in Ya'an City,Sichuan Province,the safety of the slope is calculated by the slope acceleration method,and the safety factor under normal conditions is 1.236.The slope acceleration method is used to study the reinforcement effect of slope reduction,anchor reinforcement and anti-slide pile reinforcement.At the same time,the bolt reinforcement scheme is recommended through comparative analysis.