土的自适应应力认识与研究

Understanding and study on adaptive stress of soil

设计了一种0K状态不同等应变或等应力速率连续对土样轴向加载的单轴固结试验方案,该试验方案可让土样同时经受不同荷重率、应力历时、应力路径、应力历程的作用。经过对重塑饱和黄土的单轴连续加荷、三轴连续加荷、分级加荷单轴固结试验研究,结果表明:若定义土在单轴压缩不同侧向约束条件下反应的侧压力为自适应应力;单轴侧限压缩试验主动施加的竖向压力与实测的侧向土压力之差为土的自适应剪应力,除了不受孔隙水压力的影响外,更重要的是,实测与分析结果证明,土的单轴侧限压缩应变量与自定义的自适应剪应力具有唯一的影响关系。

The soil samples are subjected to different load rates, stress durations, stress paths and stress courses in continuous load rate unconfined compression tests. If the lateral pressure of uniaxial unconfined compression tests is defined as the adaptive shear stress of soils, the difference between the axial and lateral pressures of the uniaxial unconfined compression tests is defined as the adaptive shear stress of soils. The experimental studies show that the adaptive shear stress is not affected by the pore water pressure. More importantly, the experiment and analysis have proved that the uniaxial unconfined strain of reconstituted saturated clay samples has the unique relationship with the adaptive shear stress.