深圳海积软土基于CU试验的修正剑桥模型

通过室内试验测定了深圳地区某典型淤泥质粘土的修正剑桥模型参数,基于固结不排水剪切(CU)试验的有效应力路径建立了所述软土的应力应变本构方程,利用4/5阶龙格库塔法求解了微分方程的数值解,并通过计算值与试验值进行对比,验证了修正剑桥模型对于深圳海积软土的适用性。临界状态有效应力比M值通过CU试验测得,为得到CU试验的有效应力路径方程,将孔隙水压力随偏应力的变化关系采用二次多项式拟合,拟合效果较好。从土的本构关系理论出发,通过室内试验与结果分析,测定了深圳地区某典型软土的修正剑桥模型参数,并通过对照组的试验予以预测和验证得到了较理想的结果。

Modified Cam-Clay Model Based on the CU Test about Marine Soft Soil in Shenzhen

The modified cam-clay model parameters about typical silt clay in Shenzhen were gained through laboratory test, and then the stress strain constitutive equation was established according to the effective stress path of consolidated undrained shear (CU) test, followed by the numerical solution of differential equation by applying 4/5 order Runge-kutta method. Finally, modified cam-clay model was verified that it was suitable for the soft soil in Shenzhen by comparing calculation and tested value. The critical state and effective stress ratio(M)can be acquired by CU test. In order to get effective stress path equation for CU test, we describe the relationship between pore-water pressure and deviatoric stress by applying quadratic polynomial fitting method, and the imitative result is reasonable. Based on the analysis of soil constitutive model theory, laboratory test and results are studied in order to determine the parameters of modified Cam-Clay model about certain typical silt clay in Shenzhen. And the matched group laboratory test shows a good prediction about these parameters and verified deducted conclusion.