Accurate control of hanger rod forces is crucial for ensuring structural safety and effective force distribution in long-span bridge construction. Traditional contact-based force measurement methods, such as strain gauges and accelerometers, face challenges including high costs, susceptibility to environmental interference, and intensive equipment demands, limiting their practical efficiency in complex environments. To address these limitations, this work proposes an innovative multi-stage construction method that integrates the influence matrix method with groundbased microwave radar interferometry to achieve rapid, high-precision, and non-contact force detection during hanger rod tensioning. Specifically, multi-stage construction employs a stepwise, iterative approach, dynamically adjusting rod forces in multiple stages based on real-time radar monitoring. This significantly reduces the risk of construction errors, minimizes equipment requirements, and enhances operational feasibility and safety. Based on this, a series of field tests on an actual long-span bridge validated the proposed approach, showing that after two tensioning stages, the rod forces approached target values closely, maintaining errors within 10%. The results confirm that this integrated multi-stage approach provides a practical, safe, and efficient solution for hanger rod tensioning in long-span bridges, offering substantial improvements in construction accuracy, efficiency, and applicability.
Key Words
dynamic deflection detection; ground-based microwave radar; hanger rod forces; influence matrix method; long-span bridge; multi-stage construction method
Address
(1) Huanzhong Sun, Weiqi Zheng, Zhihui Zhu, Yonghong Yang, Xingwang Sheng — School of Civil Engineering, Central South University, Changsha, China
(2) Huanzhong Sun — China Railway 14th Bureau Second Engineering Co., Ltd., Tai'an, China
