黄石淤泥质土的剪切蠕变特性及模型研究

Study on Shearing Creep Characteristics and Constitutive Mode of Huangshi Mucky Soil

通过室内剪切蠕变试验,对黄石地区淤泥质土蠕变特性进行了研究。结果表明:黄石淤泥质土的剪切蠕变变形可近似为线性特征;蠕变变形在一定剪应力水平下才能表现出来,剪应力水平越高,剪切蠕变变形越明显;在高应力下,土的粘滞性增加,流动性降低,剪切模量与时间呈下降幂函数关系;粘滞系数的变化受剪应力的影响并不大。针对试验数据采用线性回归分析法确定蠕变参数能取得较高的精度,Burgers体蠕变模型和经验型模型均能较好描述该地区淤泥质土的剪切蠕变规律。比较而言,采用经验型模型更适合于描述软土非线性剪切蠕变特性。

The shear rheological behaviors of Huangshi mucky soil by indoor test are studied. The test results that the shear creep deformation of Huangshi mucky soil is similar to linear features. The creep behaviors can be seen under some levels of Shear stress. The shear stress is higher; the shear creep deformation is more obvious, Under the high stress, the viscosity of soil increase, and the liquidity of soil decline. The shear module has power function decline in relations with time. The coefficient of viscosity has no large change with the change of shear power. According to the experimental results that linear regression analysis can make sure the creep coefficient and improve the accuracy, the creep model and experience Burgers＇ model can both rightly describe the shear creep law of muddy soil in this area. In comparison, it is good to make use of experience model to describe the character of soft soil non -linear shear creep.