三峡库区某滑坡土非饱和松弛特性试验研究及模型建立

Study on Unsaturated Relaxation Properties of Soils of a Landslide in the Three Gorges Reservoir Area and Model Construction

为了解基质吸力对非饱和土松驰特性的影响,利用GDS非饱和三轴仪的高级加载模块对三峡库区某滑坡土样开展了不同基质吸力的非饱和松弛试验,选取了与试验松弛曲线较一致的指数函数、对数函数、幂函数分别进行了曲线拟合,在对3种拟合结果进行对比分析基础上,确定了拟合精度最高的幂函数作为松弛模型,并分别求出了不同基质吸力作用下松弛曲线的模型参数。同时分析了各模型参数与基质吸力之间的相关性,并建立了模型参数与基质吸力之间的关系函数,据此建立了能反映基质吸力影响的非饱和土松弛模型。

In order to obtain influence of matric suction on relaxation properties of unsaturated soil,we conduct stress relaxation tests of unsaturated soil of a landslide in Three Gorges Reservoir area by using GDS triaxial apparatus. Exponential function,logarithmic function and power function are selected for curve fitting. Through comparative analysis,power function is selected as the relaxation model as it has maximum fitting accuracy,and the model parameters under different matric suctions are obtained. The correlations between matric suctions and model parameters are analyzed,and function relationships are built. The function relationships are substituted into the relaxation model equation and a relaxation model that can reflect the effect of matric suction of unsaturated soil is obtained.