Research on Large-Scale Tri-Axial Shear Strength Tests in Slide Zone Soil of Huangtupo Landslide

Coarse particles were got rid of in conventional strength tests of slide zone soil, which leads to distort the strength parameters of slide zone soil that is sensitive to grain grading. There is no unified way to obtain exact shear strength parameters of it. The research is to discuss how to get more accurate shear strength parameters of original grain grading slip soil of Huangtupo riverside slumping mass I#. Test samples are selected from No. 5 branch tunnel of big testing ground in the research landslide, and the slip soil with original grain composition was used for saturated consolidated-undrained large-scale shear test. On the large-scale tri-axial test equipment, shear strength test of slip soil with original grain composition are carried out for the first time. Moisture content and drained condition of the inside of low-permeability samples are discussed to prove the requirements of experiment are met. Contrasting the testing results with the results of large-scale in-situ shear tests and saturated small-scale consolidated-undrained shear test, possible reasons for the differences between them are analyzed. The research may provide some important references for reasonable shear strength parameters of slip soil with original grain composition.