Study On The Composite Coefficient Method Of Handan Silty Clay Based On Two-parameter Criterion Of The Strength

The failure process of soil mass in the process of landslide is a gradual development process.Due to the change of water content and the accumulation of strain,the shear strength parameters of soil are attenuated at different velocity,then the shear zone is formed,leading to instability of slope.Therefore,the strength parameters c and ? of the soil are closely related to the water content and should have different safety reserves.In this paper,the silty clay in Handan area is taken as the research object,and the attenuation coefficient of soil strength under different water content conditions is obtained,and the comprehensive safety factor of the slope is obtained.The main contents of this paper are as follows:(1)The newly-deposited homogeneous silty clay in Handan was used to prepare soil samples with different water contents by compaction.Then the strength parameters c?? of soil samples under different water content were measured by direct shear test.Slope model to achieve critical state of instability,c? ? value of different attenuation degree of the study.(2)The model is established by MIDAS/GTS software,and the stability of the slope is analyzed by the reduction of c?? by the change of the cohesion c and the internal friction angle ?.At the same time,the cohesion c,internal friction angle tangent Tan?,slope height H and slope slope angle ? on the sensitivity of slope stability were analyzed and studied.(3)Based on the analysis of the attenuation degree of the strength parameters of the clayey soil in Handan,the safety evaluation method of the two strength parameters with different reduction coefficient is put forward.By combining the weight parameter analysis of the soil strength parameter,Synthetic Safety Factor Method for Double Reduction Factor of Strength.The method is compared with the results obtained by the limit equilibrium method in SLIDE,and the influence of slope height H and slope angle ? on the proposed method is also studied.(4)Compare the method proposed in this paper with the shortest path method,and compare the two methods with the traditional strength reduction method.Through the example analysis,it is applied to slope stability analysis and slope design.