Investigating the Effects of Shield Tunneling on Nearby Bridge Piles Based on the Stress Release Factor

Abstract

Shield construction is the process of boring and advancing a steel liner or performing open excavation with the sides of an excavation trench lined with a shield to prevent soil wall collapse. The interactions between bridge piles adjacent to shield tunnel construction and the associated foundation engineering were investigated in the Zhengzhou area. A three-dimensional numerical model was established using Midas GTS NX finite element software to systematically study the deformation mechanism of adjacent bridge piles under different stress release factors of geological parameters. The response laws of surface settlement, lateral displacement of pile body with stress release factor, and geological parameter changes were analyzed. The results show that: (1) when the stress release rate increases from 70% to 80%, the displacement response of the surrounding soil exhibits a nonlinear increase—notably, the displacement sensitivity rises significantly once the stress release rate exceeds a specific threshold; (2) the stress release factor is constant, and the change in surface settlement for internal friction angles less than 25° is more than twice as large as for angles greater than 25°; and (3) when the stress release rate is 80% or higher and the elastic modulus is 18 MPa or lower, the lateral deformation of both the ground surface and the pile bodies enters a highly sensitive zone, where minor fluctuations in parameters may trigger drastic structural changes.