三峡泄滩滑坡滑动带土的改进Singh-Mitchell蠕变方程

进行了三峡泄滩滑坡体滑动带土的三轴排水蠕变试验研究,在此基础上给出了该滑动带土的 Singh-Mitchell 蠕变方程,即剪应力-应变关系采用指数函数,应变-时间关系采用幂函数来描述土体的流变性质。并根据分段拟合的思想,提出了改进的 Singh-Mitchell 蠕变方程,即在应变-时间幂函数中使用不同的幂值λ ,来分别模拟滑动带土的衰减、匀速和恒定蠕变。通过对比可知,改进 Singh-Mitchell 蠕变方程较 Singh-Mitchell 蠕变方程能更好地模拟流变性较小的滑动带粘土。

A modified Singh-Mitchell's creep function of sliding zone soils of Xietan landslide in Three Gorges

Drained triaxial compression creep tests of sliding zone soils of Xietan landslide in the Three Gorges area have been carried out. Based on these tests, given is Singh-Mitchell’s creep model, in which exponential function is adopted for shear stress-strain behavior and a power function for strain-time behavior. A modified Singh-Mitchell’s shear stress-strain-time behavior is presented too, in which strain-time power behavior has been simulated by subsection. Through using the different power values , which correspond to the three phases of creep, that is , damply phase, steady phase and invariable phase respectively; the capability of simulation the creep characters of the sliding zone clay can be greatly improved. So for the clay which has less creep characters, modified Singh-Mitchell’s creep model is more reasonable than Singh-Mitchell’s creep model.