桩基施工对邻近顶管隧道的扰动影响

预制桩静压施工会对桩周土体产生一定的扰动,进而对邻近既有顶管电缆隧道产生影响.顶管电缆隧道对管节的偏转和变形要求十分严格,一旦变形过大就会产生严重影响.为了确保顶管电缆隧道的正常使用,通过数值方法计算了预制桩静压施工对邻近顶管电缆隧道的影响,通过K0固结不排水剪切试验确定了软土小应变范围的参数取值,分析了桩长、桩-隧间距以及桩基挤土量对于隧道变形的影响.参考相关规范,以5 mm和15 mm变形扰动值为依据分别划分了预制桩静压施工对隧道变形强、弱影响区,为既有顶管电缆隧道周围的桩基施工提供相应的参考.

Research on the Disturbance Influence of Pile Foundation Construction on Adjacent Pipe Jacking Tunnel

The static pressure of precast piles will cause certain disturbance to the surrounding soil, which will affect the adjacent existing pipe jacking cable tunnel. The pipe jacking cable tunnel has very strict requirements on its deflection and deformation. Once the deformation is too large, it will have a serious impact. To ensure the normal use of the tunnel, this paper calculated the influence of static pressure construction of precast piles on the adjacent pipe jacking cable tunnel by numerical methods. Through K0 consolidation undrained shear test, the parameter values of the small strain range of soft soil are determined. The influence of pile length, pile-tunnel spacing and pile foundation squeezing amount on tunnel deformation is analyzed. According to relative regulations, based on the deformation disturbance values of 5 mm and 15 mm, the tunnel deformation strong and weak affected regions of the pile construction are respectively divided, which provides a corresponding reference for the pile construction around the existing pipe jacking cable tunnel.