土体侧移作用下既有轴向受荷桩性状的室内模型试验研究

堆载或开挖等引起的土体侧移对邻近轴向受荷桩的承载和变形性状可能会产生负面影响,对于这一问题目前尚缺乏充分的研究。采用室内模型试验研究轴向受荷桩在土体侧移作用下的承载和变形特性,重点分析了土体侧移、桩顶轴向荷载以及群桩效应等对桩基性状的影响。试验结果表明,桩顶轴向荷载和土体侧移的耦合作用使得桩身弯矩和位移均相应的增大;而两桩中的前桩对后桩具有遮拦效应,前桩的存在使得后桩的弯矩和变形明显变小。在工程实践中应充分重视土体侧移与轴向荷载的耦合效应对桩基性状的影响。

Model tests on behavior of axially loaded piles subjected to lateral soil movement

The construction of underground engineering or tunnel excavations will lead to displacement of the surrounding soil. Lateral soil movement may have a negative influence on the bearing characteristics of axially loaded piles. A series of model tests are carried out to analyze the behavior of axially loaded piles subjected to lateral soil movement. Effects of lateral soil movement, different axial loads and pile group effects on the response of piles are analyzed. Results from model test show that the bending moment and deflection of the piles increase with the increase of lateral soil movements or the increase of the axial loads. Furthermore, the front pile has curtain effect on the back pile. The bending moment and deflection of the back pile decrease obviously for the existence of front pile. Therefore, the coupling effect of lateral soil movement and axial loads should be taken into account in practical design of pile foundations.