中文摘要：

采用土体三轴流变仪,对南宁膨胀土在不同恒应变分级加载条件下的三轴应力松弛特性开展试验研究,探讨在不同恒应变水平下南宁膨胀土的应力松弛特征和松弛模量等变化规律。根据应力-应变等时曲线特征,研究南宁膨胀土在三轴压缩条件下的应力松弛特性。通过对试验结果的分析,建立可描述南宁膨胀土非线性应力松弛特性的经验模型。模型计算结果与试验结果吻合较好,验证了经验模型的可靠性。

英文摘要：

Using triaxial rheological apparatus,a series of tests on triaxial stress relaxation properties of Nanning expansive soil under different constant strain were carried out by step loading.The change laws of stress relaxation characteristics and relaxation modulus of the expansive soil under different constant strain levels were discussed.Moreover,according to the features of isochronous stress-strain curves,the stress relaxation characteristics of the expansive soil were studied under triaxial compression.Based on the analysis of the experimental results,an empirical model was established to describe the nonlinear stress relaxation properties of expansive soil.The model calculated results were in good agreement with the tested ones,which verified the reliability of the empirical model.