路基非饱和土动态回弹模量计算模型对比研究

作为路面结构设计的关键参数,对动态回弹模量的可靠计算一直是工程界不断探索的课题。本文收集并分析国内外已有关于路基土回弹模量的计算模型,根据自变量的不同属性,将计算模型归为两大类,第一类为将应力水平作为变量(I型),第二类是将表征湿度状态的基质吸力作为变量,这其中又分为两个子类,一是将基质吸力引入耦合到应力变量中(II1型)；二是将基质吸力剥离出来作为独立变量(II2型)。然后结合2种土样的循环动三轴试验数据,对3类计算模型的可靠性及适用性进行对比评价。结果表明：将基质吸力作为单独变量(II2型)的计算模型能更真实的反映非饱和路基土动态回弹模量的变化规律,拟合度较高。

Classification and comparison of modulus of resilience calculation models of subgrade unsaturated soil

As a key parameter of pavement structure design, the reliable calculation of dynamic modulus of resilience has been a subject of constant exploration in the engineering field. This paper collects and analyzes the existing calculation models of subgrade soil resilient modulus at home and abroad. According to the different properties of the independent variables, the calculation models are divided into two categories. The first one is to take the stress level as the independent variable (type I), the second is to take the matrix suction which represents the humidity state as the independent variable, which is divided into two sub categories, one is to introduce the matrix suction into the stress variable (II1). The second is to separate the matric suction as an independent variable (type II2). Based on the cyclic dynamic triaxial test data of two kinds of soil samples, the reliability and applicability of the three calculation models are compared. The results show that the matrix suction as a separate variable and the stress variable in the form of product can more truly reflect the response law of resilient modulus.