Effect of Sample Reconstitution Methods on the Behaviors of Granular Materials under Shearing

摘要

The effect of sample reconstitution methods on the behavior of sand under shearing is investigated by using the first commercially available Variable Direction Dynamic Cyclic Simple Shear System. Three sample reconstitution methods are used in this study, which are as follows: the dry funnel method, air pluviation, and dried wet tamping. Because only dry specimens can be tested in many simple shear apparatuses, in this study, a new method called dried wet tamping is used to model the soil fabric generated by the wet tamping method, wherein the soil sample prepared by wet tamping is dried before being tested. Leighton Buzzard sand at various relative densities is tested in monotonic, one-directional cyclic, and two-dimensional circular cyclic simple shear tests. Experimental results show that different sample reconstitution methods have limited effects on the shear behavior in monotonic loading tests. On the contrary, the sample reconstitution methods greatly influence the dynamic responses of sand, including the undrained one-dimensional cyclic and two-dimensional circular cyclic loading. The liquefaction resistance is the greatest using the dried wet tamping method, followed by the dry funnel method and air pluviation method. These test results are also compared with previous studies on sample reconstitution methods, and their similarities and differences are analyzed.