公路梁桥改扩建公铁两用桥桩基础再利用可行性研究

Feasibility Study on Reuse of Pile Foundation of Highway-Cum-Railway Bridge in Reconstruction and Extension of Highway Girder Bridge

以南沙港铁路鸡鸦水道既有公路桥改扩建公铁两用桥工程为依托,对新老桩基础在荷载作用下的应变情况进行了测试,并建立包含既有桩基础和新建桩基础的三维有限元模型,分析了桩长和桩型对新老桩共同工作时荷载分担比例的影响规律。结果表明:新老桩荷载分担比例受桩长影响较小,受桩型影响明显;端承桩各桩承担上部竖向荷载较均匀,摩擦桩受群桩整体不均匀沉降影响造成各桩受力不均匀,外围老桩承担竖向荷载比重大。

Based on the reconstruction and expansion of the existing highway bridge in Yalu Waterway of the NanSha Port Railway,the strain conditions of the new and old pile foundation under load were tested.A three-dimensional finite element model including the existing pile foundation and the new pile foundation was established.The influence of pile length and pile type on load sharing ratio of new and old piles was analyzed.The results show that the load sharing ratio of new and old piles is less affected by the pile length and is obviously affected by the pile type.The end-bearing piles bear the upper vertical load more evenly.The friction pile is affected by the overall uneven settlement of the pile group,resulting in the uneven stress of each pile.The old side pile bears a large proportion of vertical load.