Ring Shear Study On Double Layers Of Saturated And Dry Loess At Nanyuan Landslide Of Jingyang,Shanxi

Loess landslide is the most serious geological disasters in Northwest China.And with the rapid development of the western economy and the activities carried out,Study on Mechanism of Disaster of Loess Landslide has become a hot topic in the field of engineering geology.Wherein the sliding speed,sliding distance away,hazards and other characteristics of high-speed remote loess landslide landslide hazard study is one among the difficult problems.And there is a relative sliding phenomenon in the binary structure composed of the sliding body and the underlying soil.However,the analysis and study of this unique phenomenon is not yet mature.Therefore,the heterogeneity can be established to reflect the shear mechanical properties of different soils Soil relative sliding model is very necessary.As an important research sliding zone soil test equipment mechanical properties under high shear conditions,ring shear testing machine with a high degree of automation,measurement accuracy,large load capacity and the ability to simulate different stress conditions,etc.guarantee its results true and accurate.Its unique upper and lower ring separable characteristics,for the heterogeneous soil mechanical properties of the analysis and the establishment of the model provides a convenient.In this paper,high-speed remote loess landslides as the research object,in large high-speed high-pressure ring shear tests as the main means,for wet and dry single loess and of wet and dry double loess in different static method to stress down,Ring shear tests carried out under large displacement and different shear rate.Basic characteristics and laws of their produce,obtain the corresponding physical and mechanical parameters of indicators.This paper works are as follows:(1)Based on the study of the domestic and foreign scholars,this paper expounds the distribution of loess,the loess property and the south landslide in Jingyang,and analyzes the characteristics of the large-scale high-speed remote landslide,and puts forward the important academic and practical significance of this study.(2)The study of loess soil test equipment in general,numerical simulation(PFC)method are introduced in detail the principles and conditions applicable,and in this testthe selected large high-speed ring shear apparatus to make the same presentation.(3)Through multiple sets of experiment comparative analysis of the wet and dry loess shear displacement — shear stress curve under different normal stress and different shear rate conditions shear displacement,linearly fitted to its shear strength parameters and analyzed its results,and summarized its results also.(4)By the dry and wet double-layer(below the wet loess,above the dry loess)loess composed of heterogeneous soil were studied ring shear test,and to saturated loess,dry loess and double-layer loess three kinds of test kind of shear test results were compared and analyzed.The shear behavior of saturated loess,dry loess and double layers wet and dry loess during ring shearing was revealed by a large number of experimental results,and the reason of shear resistance and shearing strength parameters under large shear condition was revealed,Which is of reference value for the study of relative sliding between heterogeneous soils.