Taiwan Railway's Resilience Reconstruction of Xiaoqingshui Stream Bridge via Pier-Free Truss Design

In response to severe debris flows triggered by compound disasters in eastern Taiwan in 2024, railway engineering teams overhauled the Xiaoqingshui Stream Bridge on the North-Link Line. Rather than restoring the damaged multi-span concrete pier structures, the project implemented 40-meter single-span through steel truss bridges without riverbed piers, raising beam clearance by 85 cm and expanding discharge capacity by 10%. Westbound recovery completed in 149 days, while eastbound proactive reconstruction leveraged an advance-readiness framework to finish within a 42-day line-suspension window.

Key takeaways

• Both westbound and eastbound bridges adopted 40-meter single-span pier-free steel truss designs, raising beam levels by 85 cm and enhancing cross-sectional flood discharge by 10%.
• Structures utilized A709 high-strength steel with fully bolted connections; modular prefabrication was completed off-site within 42 days to avoid hazardous on-site welding.
• The eastbound bridge used an advance-readiness method, completing pier cap extensions and cable relocations under live electrified traffic over 44 days, allowing bridge replacement in 42 days of track closure.
• A multi-tiered monitoring framework combined satellite multi-spectral data, drone point-cloud models, and real-time hydrological gauges with guide walls and multi-agency catchment clearing.