Impact of a large and shallow twin-tunnel excavation on a high-speed railway bridge and related protective measures: A case study

作者：Wenhui Yang, Dingwen Zhang, Daniela Boldini · 发表于：Underground Space · 年份：2025 · DOI：10.1016/j.undsp.2025.05.001 · 被引用次数：4 · 研究领域：Geotechnical Engineering and Analysis、Geotechnical Engineering and Underground Structures、Geotechnical Engineering and Soil Stabilization

• First large-diameter shield tunnel built under an active high-speed railway bridge. • Innovative steel casing method ensures safety under limited construction height. • Detailed monitoring tracks impacts on soil, bridge piers, and isolation piles. • Advanced 3D modeling predicts pier displacements, guiding protective measures. • Offers vital reference for future tunnels under high-speed rail infrastructure. This case study examines a landmark engineering project in Suzhou, China, involving the construction of two large-diameter (13.2 m) shield tunnels beneath an active high-speed railway (HSR) bridge. This pioneering project is the first of its kind in both China and the world. Advanced numerical simulations were conducted to rigorously assess construction risks. To ensure the operational safety of the existing HSR bridge, an innovative protective system, consisting primarily of segmental steel casing concrete pile barriers, was employed. A comprehensive network of monitoring sensors was strategically deployed to track soil, pile barrier, and pier displacements throughout both the protective and tunnelling phases. Simulation results indicated that tunnelling without protective measures could cause pier displacements of up to 3.1 mm along the bridge—exceeding the maximum allowable displacement of 2 mm in accordance with regulations. Monitoring data revealed that the maximum pier displacement during protective scheme installation was limited to 0.5 mm. With these protective m...