关键词: 成样方法, 应力路径, 饱和粉砂, 固结排水剪切, 剪胀性

Abstract: Consolidate drained shear tests were carried out on saturated natural silty sand using stress-controlled static triaxial shear apparatus. The samples of 50% relative denseness were prepared using dry-tamping method and wet-tamping method while the consolidation drained shear tests were carried out in three kinds of stress path conditions of CTC, TC and RTC. The experimental results of stress-strain relationship, volumetric strain rule and shear strength indexes were obtained, and the influence of sample-preparing methods on experimental results was studied. The results shows that, in three different stress paths, the samples of dry-tamping method have strain softening and shear dilatation phenomenon, while the samples of wet-tamping method have strain hardening and shear contraction phenomenon. The peak values of principal stress difference from dry-tamping method are all higher than those of wet-tamping method, and the difference between peak values of two sampling methods under CTC is larger than others. The dilatancy of samples under RTC is the most obvious, CTC is the least, and TC is between them. All of the effective internal friction angles obtained from dry-tamping method are bigger than those obtained from wet-tamping method. In the same sample-preparing method, the effective internal friction angle of CTC is almost the same as it of RTC, and at the same time, the angle of TC is relatively close with that of RTC. The influence of stress path on effective internal friction angle is much less than that of sample-preparing methods.

Key words: sample-preparing methods, stress path, saturated silty sand, CD test, dilatancy