三峡库区马家沟滑坡滑体粗粒土蠕变试验研究

为进行滑坡建模和数值模拟的需要，针对三峡库区马家沟滑坡滑体粗粒土开展了三轴蠕变试验，研究了不同围压、不同应力水平下滑体土的蠕变变形规律。试验表明，滑体粗粒土具有明显的非线性蠕变特征，蠕变过程可分为减速蠕变和匀速蠕变2个阶段；围压和应力水平对蠕变速率和蠕变阶段划分有重要影响。采用应力-应变关系为指数函数，应变-时间为幂函数的Singh-Mitchell（简称S-M）蠕变模型描述粗粒土的蠕变特性，与试验数据对比表明，S-M蠕变模型与试验结果具有较好的一致性，能很好地描述该粗粒土的蠕变特性。

Creep tests of gravel-soil of Majiagou landslide in Three Gorges Reservoir area

In order to provide the basement of a further numerical analysis, a series of large-scale triaxial creep tests is performed on gravel-soil obtained from sliding mass of Majiagou landslide in the Three Gorges area. The test results show that the tested gravel-soil is a typical creep material, and its creep deformation characteristics are very obvious. The soil experienced two creep stages, i.e., the decay creep stage and constant speed creep stage. The data also indicate that confining stress and stress level have an effect on the creep characteristics of soil. Based on these tests, the Singh-Mitchell model is used to predict the creep strain. Compared with the original test data, the Singh-Mitchell model results have good agreement with the experimental data.