土石坝心墙接触面单元参数的标定与数值试验方法

Parameter Calibration and Numerical Experiment Methods of Interface Element for Core Wall in Embankment Dams

土石坝沥青混凝土心墙与砂砾石过渡层之间存在剪切、错动、局部嵌入等复杂力学行为,建议在两者之间设置Desai有厚度接触面单元,该单元的参数取值与单元厚度显著相关,但现有成果中围绕接触面参数和厚度关系的研究十分匮乏。因此基于有限单元法和直剪物理试验,建立了一套标定不同厚度接触面单元参数的数值试验方法。依托茅坪溪土石坝的物理试验成果,验证了该方法的可行性,并且研究了接触面各项参数随厚度的变化规律。通过某沥青混凝土心墙坝的三维数值模拟,实现了工程应用。

In the contact layer between the asphalt concrete core wall and the sand gravel transition layer in embankment dams,complex mechanical behaviors such as shearing,dislocation and local embedment are often observed.Thus,it is suggested to set a thin layer Desai interface element between them.The parameter values of the element are significantly related to its thickness.But the research on the relationship between the parameters and the thickness is rare.Based on the finite element method and the direct shear physical test,a set of numerical experiment methods for calibrating the parameters of the interface elements with different thickness are proposed.The feasibility of the proposed method is verified with the physical test results of Maopingxi embankment dam,and the relationships between the various parameters and the element thickness are studied.Also,it is successfully applied in the three-dimensional numerical simulation of an asphalt concrete core wall dam.