A Numerical Study on the Lateral Pile–Soil Interaction During the Tunneling Process in Clay

Tunneling causes stress release and lateral displacements in the soil, thereby influencing the lateral pile–soil interaction behavior in the surrounding area. In this paper, the influence of the tunneling process on surrounding pile–soil interaction behavior is studied based on numerical modeling. The passive load-bearing zone (PLZ) and non-passive load-bearing zone (NPLZ) around the pile are defined for the targeted analysis. Results show that the locations of PLZ varies with the tunneling locations. The pile section in PLZ is loaded passively (soil pushes pile), and the pile section in NPLZ is loaded actively (pile pushes soil). Also, the p–y curves in PLZ present a passive loading characteristic due to the tunneling-induced lateral soil movement, which is different from the p–y curves in NPLZ with positive soil resistances. Finally, based on the mechanism of pile–soil interaction, guidelines are discussed to protect the pile foundations subjected to tunneling.