Numerical Analysis on Pile Response to Adjacent Double-Line Shield Tunneling

With the finite element software MIDAS/GTS, the paper conducted a numerical simulation on pile response to adjacent double-line shield tunneling on soft soil strata that were increasingly rigid at ever greater depth in Hefei. The deformation characteristics of single piles of different lengths and at various locations were analyzed in this study. Results show that: during double-line tunnel excavation, short piles under deformational forces mainly incline, while bend is the major form longer piles. In addition, the deformation and stress of piles on the right side of the tunnel are larger than those on the left side of the tunnel when the double-line tunnel excavation is sequenced left first and then right. A pile in between two tunnels has relatively large horizontal and vertical displacement of and relatively great additional axial force exerted on its foundation when it is under exogenous force caused by tunnel excavation, but encounters less stress on its additional bending moment as a comparison.