内蒙古沙漠地区风积沙本构模型的研究

The Study of Constitutive Model of Aeolian Sand In Inner Mongolia Desert Area

以内蒙古沙漠地区的风积沙为研究对象。对风积沙进行了一系列的固结排水常规三轴剪切试验,试验发现邓肯–张模型能够较合理地确定风积沙的切线弹性模量,但是求取切线泊松比误差较大,不能较好地描述风积沙的体变特性。针对风积沙的切线泊松比提出了新的改进模型,该改进模型把-ε3-ε1关系曲线分成两段考虑,分别用抛物线和直线进行拟合,给出切线泊松比的计算公式,得到风积沙的本构模型,并阐述了模型中各参数的确定方法。

The object of the study is the Aeolian sand in the desert in Inner Mongolia region.The Aeolian sand samples are subjected to serial consolidated drained normal triaxial shear test.The findings show that although the tangent elastic modulus of the Aeolian sand could be determined by using the Duncan-Chang model,with a large margin of error for the calculations of the tangent Poisson rations the Duncan-Chang model could not properly simulate the volumetric strain behavior of the Aeolian sand.A modified model of the Aeolian sand is then developed through presenting new volumetric strain assumptions on the basis of the test results.In the modified model the-ε3-ε1relation is considered in two separate stages;whereby the formula for the calculation of the tangent Poisson ratio is arrived at through simulations of the two stages to a parabolic curve and a straight line respectively And the method of determining the parameters of the constitutive model are also given.