Calculation Method Of Safety Factor Of Slope Reinforced By Anti-slide Piles Considering Strength Anisotropy

With the increasing comprehensive national strength of China and infrastructure construction,considerable problems of slope stability are encountered in engineering practice.It is of great significance to strictly ensure slope stability to promote social economic development and ensure the safety of life and property.As one of the effective methods to reinforce the slope and enhance its stability,anti-slide piles are widely used in slope engineering due to their advantages of simple construction technology,low cost and short construction period.However,the domestic theory of slope reinforcement with anti-slide piles is still immature,and there is no relevant criterion as a reference.Therefore,it is urgent to improve the theoretical calculation method of slope stability with anti-slide piles to provide guidance for slope engineering design.Based on the British Code(BS8006),the calculation method for the stability of the embankment reinforced by anti-slide piles has been modified,and the calculation method of the slope stability of anti-slide piles is established considering the anisotropy of soil strength.The core of this method is the limit equilibrium method.The theoretical derivation is rigorous and the calculation process is simple.The conditions of soil strength anisotropy,heterogeneity and seepage force in actual engineering are considered,and the horizontal soil arch effect is combined to solve the problem that the parameter setting of the original calculation method is not coincide with the practice.The slope model of anti-slide pile is established by finite element analysis software ABAQUS,the user subroutine which can realize the anisotropy of soil strength is written,and the modeling method and subroutine code are used together.Finally,the safety factor of each model is solved by strength reduction method and dichotomy.Combined with actual working conditions,through the analysis of model parameters,9factors affecting the stability of anti-slide pile slopes are summarized,using ABAQUS to simulate and analyze the influence of these influencing factors on the stability of the anti-slide pile slopes.Among them,the internal friction angleφand vertical cohesion c_v have great influence on the stability of anti-slide pile slope,and the smallest factor is pile diameter D.By comparing the safety factors of analytical solution and numerical simulation results under different influencing factors.It can be found that in addition to the internal friction angleφand the pile positionξchange,the trend line of the analytical solution and the numerical simulation results is significantly different.When other influencing factors change,the analytical solution and numerical simulation results trend line are substantially the same.By comparing the analytical solution with the numerical simulation results,the errors caused by different influencing factors are respectively fitted into the correction equations related to different influencing factors,thereby reducing analytical solution calculation error in actual engineering.Finally,the modified anti-slide pile slope stability calculation method is used to calculate and analyze the engineering example.It shows that the safety factor obtained by the theoretical calculation is basically consistent with the engineering example result,which verifies the effectiveness of this method established in this paper.The accuracy of the slope stability calculation method reflects the important engineering application value of this method.