顶管工程施工对邻近轨道交通高架结构的变形影响分析

Analysis of the Impact of Pipe Jacking Construction on the Deformation of Adjacent Elevated Structure of Rail Transit Project

文章基于黄陂新武湖水厂二期工程下穿武汉轨道交通21号线高架区间项目,采用Midas/GTS有限元分析软件建立三维模型,研究顶管施工对轨道交通高架区间结构可能产生的影响,并提出对轨道交通高架结构的保护措施,以保证轨道交通高架区间的安全。结果表明:顶管施工引起的邻近高架结构变形以竖向变形为主,水平变形较小,未超过容许值,满足规范要求;顶管施工导致桥桩侧摩阻力产生一定损失;顶管施工引起轨道交通高架结构产生的附加内力不大,增幅均小于3.5%;通过注入触变泥浆填充管壁外空间,可控制沉降和降低管壁与土层之间的摩擦力,增加中继环以减小单次顶推长度及最大推力,可减少顶管对轨道交通高架区间结构的影响。

Based on the Huangpi Xinwuhu water plant Phase II project passing under the elevated section of Wuhan rail transit Line 21,it uses the Midas/GTS finite element analysis software to establish a 3 D model to study the possible effects of pipe jacking construction on the structure of the elevated section of rail transit,and puts forward protection measures for the elevated structure safety of rail transit.The results show that the deformation of the adjacent elevated structure caused by pipe jacking is mainly vertical deformation with limited horizontal deformation,the deformation does not exceed the allowable value,meeting the standard requirements;a certain loss of lateral frictional resistance of bridge piles is generated due to pipe jacking construction;additional internal forces generated by the pipe jacking construction on the elevated structure of the rail transit are not significant,with the extent of increase less than 3.5%;By injecting thixotropic slurry to fill the space outside the pipe wall,it could control the settlement,reduce the friction between the pipe wall and soil stratum,and by increasing the relay rings,it can reduce the length and maximum thrust of a single jacking round,which can reduce the impact of pipe jacking on the structure of the elevated section of rail transit.