珠三角地区典型海相沉积软黏土蠕变特性试验研究

Experimental study on creep characteristics of marine sedimentary soft clay in Pearl River Delta region

针对珠三角地区典型海相沉积软粘土,利用室内三轴蠕变试验仪,进行不同围压下固结不排水剪切蠕变试验。基于试验结果,系统探讨了海相沉积软粘土蠕变特性,重点分析了海相沉积软土线性黏弹性蠕变和非线性黏塑性蠕变规律。采用理论模型与经验公式相结合的方法建立软黏土的黏塑性蠕变本构模型,其中以元件模型描述软黏土线性粘弹性蠕变特性,经验模型描述软黏土非线性黏塑性蠕变特性。采用基于MATLAB的高斯-牛顿最小二乘法,对软粘土应力应变等时曲线进行拟合,获得蠕变本构模型参数,将模型曲线与实验曲线对比,吻合度较高,验证了模型能较好地描述不同围压下海相沉积软土的蠕变特性。

For a typical Marine sedimentary soft clay in the Pearl River Delta, uses indoor triaxial creep test device under different confining pressure consolidation undrained shear creep test. Based on the system test results, this paper discusses the marine sediment soft clay creep properties, and analyses the regularity of the linear viscoelasticity marine sedimentary soft soil creep and nonlinear sticky plastic creep. By adopting the combination of theoretical model and empirical formula method to establish the sticky plastic soft clay creeps constitutive model, the component model which is used to describe linear viscoelastic creep property of soft clay,experience model to describe nonlinear sticky plastic soft clay creep property. The gauss-Newton least-square method based on MATLAB, the stress and strain of soft clay such as curve fitting, when get the creep constitutive model parameters of the model curve with the experimental curve contrast, alignment is higher, verified the model can well describe different confining pressure creep properties of sea facies soft soil.