软粘土路基三轴蠕变特性试验及模型研究

针对软粘土路基累积蠕变沉降变形的特点,开展可塑土、软塑土路基开展三轴固结不排水蠕变试验,确定软粘土路基抗剪强度,得出不同围压下软粘土破坏偏应力,为三轴固结不排水蠕变试验分级加载提供依据。鉴于软粘土非线性蠕变特性比较明显,以围压100 kPa下软粘土的蠕变试验为例,结合最小二乘法的拟合分析,建立了以幂函数为应力-应变关系,以双曲线函数为应变-时间关系的蠕变方程。该蠕变力学模型能够更好地反映和预测竹城公路软土蠕变特性。

The Tri-Axial Creep Characteristics Test and Creep Model Research of Soft Clay Subgrade

According to the characteristics of cumulative creep subgrade of soft clay,the triaxial consolidated undrained test was conducted with plastic and soft plastic soil for shear strength.The damage partial stress was obtained under different confining pressure.It offers the basis for a triaxial test classification.Due to obvious nonlinear creep characteristics,with 100kPa confining pressure creep test,the creep equation is established,combined with the fitting analysis of least square method.The stress-strain relation adopts power function,strain-time relation with hyperbolic curve.The obtained creep mechanical model can reflect and forecast the creep characteristics of Zhucheng highway.