近距离顶管施工对下方既有区间隧道结构的变形影响分析

Analysis of deformation influence of short-distance pipe jacking construction on existing subway tunnel structure below

以南京石头城路污水管顶管上穿既有地铁区间隧道工程为例,通过midas GTS三维有限元建立顶管施工全过程对区间隧道的影响分析,从工作井施作、工作井顶进、工作井回筑、配套浅层管线施作进行全过程分析,研究表明:下方区间变形最大处基本位于工作井正下方位置,投影位置两侧随水平距离增加逐渐减小;区间隧道水平位移和竖向位移随箱涵施工变形规律较为相似,均在顶管工作井开挖到底后达到最大值,工作井回填阶段,下方区间隧道变形有所回弹;浅层管线综合配套对下方区间隧道影响较小。

In this paper,based on the sewage pipe jacking project of Shitoucheng Road in Nanjing passing through the existing subway tunnel as an example,the influence of the whole process of pipe jacking construction on the tunnel is analyzed by midas GTS three-dimensional finite element,and the whole process is analyzed from the working well construction,jacking,working well reconstruction and supporting shallow pipeline construction.The research shows that the maximum deformation of the lower section is basically located directly below the working well,and both sides of the projection position gradually decrease with the increase of horizontal distance,the horizontal displacement and vertical displacement of the interval tunnel are similar with the deformation law of the box culvert construction,and both reach the maximum value after the pipe jacking working well is excavated to the bottom,and the deformation of the lower interval tunnel rebounds in the backfilling stage of the working well,and the comprehensive supporting of shallow pipelines has little influence on the tunnel below.