土石混合料K-G模型参数试验研究

为获取土石混合料的物理力学特征,以指导土石混填路基的设计和施工,对土石混合料的本构特征以及如何有效地获取其本构参数进行了研究。采用修正的内勒K-G模型作为土石混合料的非线性弹性本构模型,推导出了切线体变模量Kt和切线剪切模量Gt的线性表达式。采用大型土石混合料三轴试验机,利用图解法确定Kt、Gt线性表达式中各个参数。结果表明:(1)采用修正的内勒K-G模型作为土石混合料的非线性弹性本构模型,力学概念清楚,参数易于测定;(2)采用大型三轴试验方法测定土石混合料的K-G模型参数切实可行;(3)K-G模型中考虑了剪应力对体积变形模量影响的修正,因而K-G模型适用于具有剪缩或剪胀性的土。

Test Study on K-G Model Parameters of Soil-stone Mixture

Constitutive characteristics of soil-stone mixture and the way to obtain the constitutive parameters were researched in order to acquire the physical mechanical characteristics of soil-stone mixture and instruct design and construction of soil-stone subgrade.Choosing modified Naylor K-G model as non-linear elastic constitutive model of soil-stone mixture,linear equation of tangent volume change modulus(Kt) and tangent shear modulus(Gt) were derived.The method of measuring Kt and Gt in modified Naylor K-G model by large-scale triaxial test was introduced,the graphical method of calculating all parameters in the linear equation above based on actual testing curve was also illuminated.It is concluded that:(1)mechanical conception is explicit and parameters is easy to be measured by choosing modified Naylor K-G constitutive model;(2)the method of measuring K-G model parameters for soil-stone mixture by large-scale triaxial test is feasible;(3)the K-G model is applicable to soil which has shear contraction or dilatation features,as the influence of shear stress on modulus of volume change is considered.