干旱区生态环境知识资源中心

Through various types of quick shear test, completely grasp the shear deformation characteristic of aeolian sand in Gurbantunggut Desert. The test result shows that the shear deformation curve of aeolian sand is influenced obviously by relative compactness. When the latter one is lower than 95%, the peak doesn't appear; when being greater than 95%, the peak value may appear frequently. With increase of compactness and vertical pressure, the differential value between peak shear strength and residual shear strength also increase; the influence on residual shear strength by compactness, vertical pressure and water content rate is less, the greater influence mostly appears when the peak shear strength is over 90%, showing that the aeolian sand is provided with obvious shear dilatancy and shear contraction. Under unsaturated water while testing, the shear strain is between 0.64%similar to 1.12% when the peak value appears; Under unsaturated water while testing, the shear strain may increase obviously so as to cause that the peak value for shear deformation curve uneasily appears. The mechanism lies in the complicated change and comprehensive influence of connection between capillary force and film water caused by change of compactness and water content ratio.