Influence of the Construction of the Bridge Pile Foundation on the Adjacent Operating Subway Tunnel Considering Creep Characteristics of Stratum
To investigate the impact of the stratum creep effect caused by the construction of bridge pile foundation on the safe oper-ation of adjacent subway tunnels,the soil creep model around the tunnel was determined by the creep tests under unloading conditions.In addition,the numerical simulation FLAC3D and field monitoring were employed to analyze the vertical displacement,horizontal dis-placement and stress distribution of subway tunnels during the pile foundation excavation.The results show that the generalized Kelvin model can accurately describe the creep behavior of clay under unloading process.After pile excavation,the lining displacement of the adjacent subway tunnel increases continuously and then tends to be stable.With more piles being excavated,the subway tunnels exhib-its a sinking and outward displacement trend,and the smaller the minimum distance between pile and tunnel,the more significant the influence of the pile construction on the tunnel.In addition,arranging piles on both sides of the tunnel can effectively reduce the final horizontal displacement of the tunnel haunch during pile excavation,which is conducive to the safe and stable operation of the subway tunnel.
pile foundation constructionoperating subway tunnelstratum creeptunnel displacements