基于三轴试验与离散元模拟的路基土力学特性研究

Research on mechanical properties of subgrade soil based on triaxial test and discrete element simulation

针对宿州市学府大道路基砂土,通过室内土工试验得到其基本物理性质指标,并结合室内三轴试验,分析不同相对密实度下砂土的应力-应变特性和体积应变特性及其变化规律。结果表明:在固定围压下,砂土的相对密实度越大,砂土抗剪强度和抗变形能力越强,而且砂土的内摩擦角与相对密实度呈正相关,即随着相对密实度的增大而增大。此外,通过建立与室内试样相同的离散元数值模型,利用PFC3D软件对其展开模拟试验研究,并与室内实验结果对比,得到与室内试验一致的结果,说明利用离散元数值模拟方法的正确性。

In this paper,the basic physical property indexes of subgrade sand of Xuefu Avenue in Suzhou City are obtained through indoor geotechnical test.Combined with indoor triaxial test,the stress-strain characteristics and volume strain characteristics of sand under different relative compactness are analyzed.The result shows that under fixed confining pressure,the greater the relative density of sand,the stronger the shear strength and deformation resistance of sand,and the internal friction angle of sand is positively correlated with the relative density,that is to say,it increases with the increase of relative density.In addition,through the establishment of the same discrete element numerical model as the indoor sample,the PFC3D software is used to carry out the simulation test research,and compared with the indoor experimental results,the results are consistent with the indoor test,which shows the correctness of the discrete element numerical simulation method.