关键词: 被动桩, 透明土, 模型试验, 埋置深度, 遮拦效应

Abstract: In the traditional model test, the pile deformation subjected to soil movement is measurable, while the soil displacement around the pile is difficult to obtain. Therefore, a model test system was designed based on the transparent soil (mixed by fused quartz and a pore fluid with a matching refractive index), particle image velocimetry (PIV) and optical measurement system. A series of model tests were carried out to measure the soil deformation in a non-intrusive way. By analyzing the images of multiple horizontal and vertical slices, a three-dimensional displacement field was obtained. The results show that transparent soil material is technically feasible for studying the displacement field of soils around passive piles. The results also indicate that the shielding effect, i.e. displacement difference between the back and side of the pile, increases with the embedment depth of the pile at the same lateral displacement. Furthermore, a finite element model was calibrated by experiment results, and parametric studies were conducted on the effects of movement profiles and pile diameter. Numerical results indicate that the influence degrees of the soil lateral displacement profile on the soil shielding are classified into rectangular, paraboloid and triangle, respectively. In addition, this shielding effect is positively proportioned to the pile diameter.

Key words: passive pile, transparent soil, model test, embedment depth, shielding effect