Effect and evaluation model of adjacent pile construction on high-speed railway piers in soft soils

Abstract

The unclear impact of small-spacing construction between new road piles and railway piers in China's coastal soft soils can threaten the safety of operating high-speed railways. By field monitoring and numerical simulation tests, this study examines the deformation characteristics of railway piers and the surrounding stratum due to adjacent pile construction in soft soils. The stratum-lateral deformation (SLD) and the displacement of the bridge pier group with various pile-forming processes or pile construction schemes were measured in field monitoring. Furthermore, the intricate interplay between varying pile diameters and spacing was examined using comprehensive numerical methodology. On this basis, a comprehensive evaluation model for the Construction Deformation Comprehensive Index (CDCI) was established to compare the multi-stage combined effects of pile construction. The results indicate that the bored pile drilling and concreting procedures significantly affect the deformations of the stratum and pier. Specifically, a negative correlation is observed between stratum deformation and the bored pile's distance and depth. The most significant deformation is in the depth direction within the three-direction pier profile. The displacement amplitude caused by single-pile construction surpasses about 2–3 times that of non-construction. Additionally, the CDCI could provide valuable insights for evaluating the holistic impacts on stratum and pier deformation in similar pile construction projects.