路桥过渡段CFG桩地基处理及参数优化研究

Study on Foundation Treatment and Parameter Optimization of CFG Pile in Road-Bridge Rransition Section

为完善路网结构在城市中往往需要设置跨河或跨江桥梁,桥头跳车问题越来越受到关注。本文以玉林市金玉路桥为例,设计采用CFG桩对过渡段进行地基处理,采用有限元分析方法对关键的桩长及桩间距参数进行优化研究。研究结果表明:随着桩深度的增加有效应力逐渐加大,当深度最高即在桩顶位置时,有效应力值达到最大;最大竖向位移随着施工过程外力作用下产生变化,在施加CFG桩后竖向位移变小,土体沉降得到较好控制;随着行车荷载的施加,土体受压沉降增大,固结半年后最终整个模型位移趋于稳定。桩长并不是越长越好,而应该根据实际地质条件确定;随着桩间距的增加,桩身轴力随之增大,针对本工程,采用桩间距为1.2m为最佳参数,所得结论对于今后类似工程的设计提供参考。

In order to improve the road network structure,it is often necessary to set up cross-river or crossriver bridges in cities,and the problem of vehicle bumping at bridgehead has been paid more and more attention.In this paper,taking the Jinyu Road Bridge in Yulin City as an example,CFG piles are designed to treat the foundation of the transition section,and the finite element analysis method is used to optimize the key pile length and pile spacing parameters.The results show that the effective stress increases gradually with the increase of pile depth.When the depth is the highest,that is,at the top of the pile,the effective stress reaches the maximum;The maximum vertical displacement changes with the external force during the construction process.After the CFG pile is applied,the vertical displacement decreases and the soil settlement is well controlled;With the application of driving load,the compression settlement of soil increases,and the displacement of the whole model tends to be stable after consolidation for half a year.The pile length is not the longer the better,but should be determined according to the actual geological conditions;With the increase of pile spacing,the axial force of pile body increases.For this project,the pile spacing of 1.2m is the best parameter.The conclusions can provide reference for the design of similar projects in the future.