Many design guidelines have been proposed for piled embankments, most of which consider piles or columns as rigid inclusions. In this study, a small-scale physical model test was performed to investigate the load transfer mechanism of a geotextile-reinforced sand layer over a soft subsoil improved by semirigid columns. A multi-stage load was applied at the top of the sand layer until the columns started to yield. When the columns yielded, a reverse load transfer was observed. Vertical stresses were measured and analyzed in terms of efficacy and stress reduction ratio (SRR) with a comparison of existing design guidelines for assessing soil arching. Among the reviewed guidelines, the approach recommended by the Dutch guidelines provided the closest results to the experimental data, whereas the one adopted by the American guidelines predicted well the change in efficacy and SRR under different surcharge loads. However, the load transfer mechanism after the yielding of columns is beyond the scope of the existing design guidelines. In addition, it was found through regression analysis that the increment of vertical stresses on columns and surrounding soil followed an inclined line under partially undrained conditions during loading stages and a curve during consolidation.

针对桩基路堤提出了许多设计指南，其中大多数将桩或柱视为刚性包含物。在本研究中，进行了小型物理模型试验，以研究半刚性柱改良的软土上土工织物加固砂层的荷载传递机制。在沙层顶部施加多级载荷，直到柱开始屈服。当柱屈服时，观察到反向负载转移。根据功效和应力降低比 (SRR) 测量和分析垂直应力，并与评估土拱的现有设计指南进行比较。在审查的指南中，荷兰指南推荐的方法提供了最接近实验数据的结果，而美国指南采用的方法很好地预测了不同附加负荷下功效和SRR的变化。然而，柱屈服后的荷载传递机制超出了现有设计指南的范围。另外，通过回归分析发现，在部分不排水条件下，加载阶段柱子及周围土体的竖向应力增量呈斜线分布，固结过程中呈曲线分布。