应力路径对填土应力应变关系的影响及其应用

本文对若干砂性土和粘性土进行了多种应力路径条件下的三轴试验,以揭示应力路径对填土的应力-应变特性的影响。并针对土坝实际应力变化情况,着重探讨了等应力比（σ₁/σ₃比值为常数）应力路径条件下土的应力-应变关系的规律性。提出了较接近于等应力比试验实测成果的指数模型,并用之于研究土坝在施工期的应力及变位分布,得出应力路径对土坝变位分布计算成果有重大影响的结论。本文还将考虑应力路径的指数模型与邓肯-张不考虑应力路径的双曲线模型在土坝有限元计算中的应用作了对比。

The Influence of Stress Path on the Stress-strain Behavior of Earthfills and its Application

For the purpose of exposing the influences of stress path on the stress-strain behaviors of earth fill, a lot of experiments were performed in the triaxial shear apparatus by using a variety of stress paths on various specimens of different soil types, involving cohesionless, also cohesive.According to the practical variation of stress distribution in the earth-rock dams, the laws of the stress-strain relationships under the condition of constant stress ratio （σ1/σ3=const.） stress path were emphatically discussed.An exponential model, which better reflects the results obtained from the experiments under the condition of constant stress-ratio path, was suggested.The application of this model to calculate the stress and displacement distributions in an earth dam during construction period comes to the conclusion that the stress path exerts an important influence on the displacement distribution in earth dam, rather than the stress distribution.In this paper, a comparative work was presented, taking stress path in consideration or leaving it out in the finite element method calculation of earth dams （i.e. comparison of exponential model with Duncan-Chang model）.