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为研究和分析软土地区桩板结构路基的沉降特性,采用离心模型试验方法对不同预压时间(6/12个月)下的桩板结构路基进行了模拟试验。试验结果表明,桩板结构路基沉降主要发生在施工期,预压时间超过16个月后,沉降比例超过80%;预压土卸载期间路基回弹与否与土层性质和预压时间有关;超载预压可以显著降低工后沉降,预压12个月后路基工后沉降相比预压6个月沉降减小了71%;在桩板结构路基施工过程中,桩基存在负摩阻力,中性点位置的变化是一个动态的过程,其与桩长的比例在0.47~0.70之间。
In order to study and analyze the settlement characteristics of the pile foundation subgrade in soft soil area, the centrifuge model test was used to simulate the pile foundation subgrade under different preloading time (6/12 months). The test results show that the subgrade settlement of the pile structure mainly occurs during the construction period. After the preloading time exceeds 16 months, the settlement ratio exceeds 80%. Whether the subgrade rebound during the unloading of the preloading soil is related to the nature of the soil layer and the preloading time; Overloading preloading can significantly reduce the post-construction settlement. After 12 months of preloading, the post-construction settlement of the subgrade is reduced by 71% compared with that of the pre-compression 6 months. During the construction of pile-structure subgrade, there is negative friction resistance, The change of neutral point position is a dynamic process with a ratio of 0.47 ~ 0.70 with pile length.