Investigation on the Influence of Active Underpinning Process on Bridge Substructures during Shield Tunnelling: Numerical Simulation and Field Monitoring

The pile foundation cutting and underpinning process during shield tunnelling significantly impacts the stability of bridge substructures. In this paper, tunnel area from Hongguzhong Avenue Station to Yangming Park Nanchang Metro Line 2 was taken as research subject, which crosses project south approach section Bayi Bridge. Through numerical simulation on-site monitoring analysis, influence active on deformation substructure studied. First, through analyzing conditions comparing technical solutions, an gantry technology proposed, specific construction steps were determined. On basis, for C15 with most complex working conditions, ABAQUS software applied simulate jack-up, unloading pile-cutting construction, displacement development pier, beam new whole analyzed. Finally, data technology’s feasibility safety further verified. At same time, according analysis results piers, beams piles, finite element nearly trend shown by results, main structures lower part small within control range. above work verified applicability type in condition single-column single-pile narrow space curved section, is worthy promotion application.