桩承式围堤对邻近桥梁桩基的影响
Effect of piled embankments on adjacent piles for bridge abutments
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摘要: 桩承式围堤是将上部围堤或堆载荷重通过桩筏基础传递到深层较硬的土层,减少由于围堤或堆载对邻近桩基产生负摩阻力和侧向推力的一种构筑物。本文采用基于Geddes应力解的桩筏基础简化分析方法,以嘉兴港海盐港区三期围堤与杭州湾跨海大桥的穿越段为例,对桩承式围堤对邻近桩基产生的负摩阻力和侧向推力进行了理论研究,并与三维弹性和弹塑性数值模拟结果进行了对比分析。结果表明:①桩承式围堤可有效降低围堤或地面堆载等荷载条件对邻近桩基的影响;②本文采用的简化分析方法与弹性和弹塑性三维数值模拟结果吻合较好,可作为桩承式围堤结构基础的分析和设计方法。Abstract: Piled-raft foundations could be employed to transfer loads induced by embankments or surcharges to stiff stratum through soft soil strata and thus to mitigate negative skin friction and lateral pressure on adjacent pile foundations,such as for bridge abutments.Using a simplified method based on Geddes stress solutions as well as 3-dimensional numerical analysis with elastic and elastoplastic constitutive models,the negative skin friction and lateral pressure on the piles of the Hangzhou Bay Bridge due to embankment of Jiaxing Port were evaluated.It was indicated: ① piled embankments could be effectively used to alleviate the influence of embankment or surcharges on adjacent piles;② the simplified method based on Geddes stress solutions could be adopted to assess roughly the negative skin friction and lateral pressure on piles due to adjacent pile foundations compared with the numerical analysis.