采用室内模型试验与颗粒流(PFC2D)数值模拟相结合的方法,对被动桩在砂土中土拱形成机理进行了较系统和深入的研究。研究表明,拱效应是多种因素的组合;桩间距、砂土颗粒孔隙率和桩土接触特征对土拱效应的影响最明显;桩间距小、孔隙率小、桩土接触面粗糙或密实度大的土体,易形成土拱;土拱并不是一成不变的,随着颗粒排列调整,可能在此过程中破坏或重新形成。 By means of the combination of indoor model test and numerical simulation of particle flow (PFC2D), the formation mechanism of soil arching of passive pile in sand is systematically and deeply studied. The results show that the arch effect is a combination of many factors. The effect of pile spacing, sand particle porosity and pile-soil contact characteristics on soil arching is most obvious. The pile spacing is small, the porosity is small, the interface between pile and soil is rough or dense Large soil, easy to form soil arch; soil arch is not static, with the particle arrangement adjustment, may be damaged or re-formed in the process.