基底倾斜的管桩复合地基路堤破坏模式研究

通过4组土工离心模型试验,研究了山区底面倾斜的软土层管桩复合地基路堤破坏模式。基于底面倾斜的天然软基路堤变形及失稳破坏特点,分析了桩端嵌入硬土层深度和桩顶格梁对于山区管桩复合地基路堤变形及失稳破坏模式的影响。试验结果表明,倾斜软土管桩复合地基上的路堤破坏模式主要有:(1)当桩端嵌入硬土层较深时,复合地基易发生下坡坡脚附近的桩体倾倒和桩间土绕流破坏;(2)桩端嵌入硬土层较浅时,复合地基易发生桩体向一侧的倾覆破坏,并伴随一定的桩间土绕流破坏,桩体倾覆程度显著大于桩端嵌入硬土层较深的情况;(3)当加格梁联系管桩桩顶时,复合地基易发生桩间土的绕流破坏。

Failure mechanisms of embankment on inclined soft foundation reinforced by pipe piles

Four groups of centrifuge model tests are performed to investigate the failure mechanisms of embankment on inclined soft foundation reinforced by pipe piles. The influences of embedded depth of pile toe into stiff stratum and lattice beams are analyzed with comparison to the natural inclined soft ground situation. The results show that the failure mechanisms are as follows: (1) For the deep embedded situation, soil may flow around piles, leading to leaning of piles at the downhill side and overall failure; (2) For the shallow embedded situation, soil also flows around the piles, leading to more leaning of piles and overall failure; (3) The lattice beams are efficient in preventing piles from leaning, but soil still flows around piles.