原状黄土连续加荷k_0固结试验研究

Research of Intact Loess through Continuous Loading k_0 Consolidation Tests

采用恒荷重速率试验法,对甘肃陇西Q_3原状黄土进行了k_0固结试验。根据对试验数据的分析,认为原状黄土由于结构性的影响,其变形分三个阶段,依次为结构基本完好阶段、结构破坏阶段、重塑阶段。第一阶段土体变形微小,可不予考虑,第二和第三阶段应变与轴向应力的对数间近似直线关系,可用于计算荷载连续施加过程中土体的变形。当应力稳定后,应变与时间之间符合双曲线关系模式,可用于计算荷载稳定后的土体变形。

A series of k_0 consolidation tests under constant rate of loading were carried out on the loess (Q_3), which comes from Longxi area in Gansu province. Based on the analysis of the experimental data, the deforming process of the intact loess is divided into three stages because of its special structure. In the first stage, its original structure is intact on the whole. In the second one, its original structure is destroyed. In the third one, its new structure is formed. The deformation produced in the first stage is minute and can be ignored. In the following stages, the relationship between axial strain and the logarithm of the axial stress is approximately linear, which can be used to calculate the deformation in the process of continuous loading. When stress is unchanged, the relationship between axial strain and time is almost hyperbolic, which can be used to calculate the deformation in the process of the stabilization of loading.