主动侧向受荷桩桩周土的影像观测与数值模拟

在室内模型试验中对模型桩顶施加水平荷载，分别采用数字照相无标点变形量测系统及配套量测分析软件形象地再现了不同密实度砂土中桩周土体及地表土体水平位移分布规律。对双桩的地表水平位移分布情形进行观测分析，结合桩顶位移与水平荷载的关系研究了桩间距对桩与桩之间的相互作用的影响。应用颗粒流程序PFC2D模拟一定深度平面内桩周土体位移，揭示了主动桩桩周土的颗粒流动性状及桩间距对桩-土相互作用的影响。结果表明，主动受荷桩桩周砂土位移场呈两个纺锤体状；砂土密实度增加，桩前砂土变形范围增大；桩间距越小，相邻桩相互影响越明显。

Image observation and numerical simulation for sand around active laterally loading pile

Through applying horizontal loads on pile top in model test,the displacement distributions of soils on the upper-surface and around piles are analyzed by the non-target digital photography deformation measure system.The surface horizontal displacement of sand around dual-piles is observed.The effect of space between piles on the interaction of piles is studied combining the relationship between displacement of pile top and horizontal load.Particle flow code in two dimensions(PFC2D) is introduced to simulate the displacement of sand at some given depth.The particle flowing behavior of sand around active pile and the effect of space between piles on the pile-soil interaction are revealed.The results show that the displacement field of sand around piles seems two fusiform bodies;the deformation region of sand in front of pile extends with the increasing of compactness of sand;the effect of interaction between piles is obvious with small pile space.