膜袋砂围堰荷载下软土地基破坏分区特性研究

Characteristics of failure zones of soft soil foundation under flexible load of sandbag cofferdam

膜袋砂围堰对地基的作用是一种典型的柔性荷载,该荷载作用下的软土地基的破坏模式及潜在滑裂面与刚性基础荷载有所不同。针对这一问题,设计并完成了一组室内模型试验,模拟膜袋砂围堰的填筑过程,观测获得了围堰填筑过程中和加载完成后软土地基的变形形态。基于模型试验得到的软土地基位移矢量和裂缝形态,参考传统地基承载力理论,提出了一种新的地基破坏分区方法,并用数值模拟方法分析了该破坏分区的合理性。新的分区方法主要改变了软土地基破坏时主动区和过渡区的划分,对于软土地基破坏分区是一种新的认识。

Sandbag cofferdam applies flexible load on soil foundation. The failure mode and sliding surface of soft soil foundation under sandbag cofferdam should be significantly different from that under rigid base. Aimed to get better understanding about this problem, a model test is conducted to simulate the construction process of sandbag cofferdam, in which the displacement of soil is observed. Based on the results of model tests, a new failure zone is proposed. The finite element analysis is used to verify the reasonability of this new failure zones.