China Conducts a Comprehensive "Wind-Induced Vibration Check-Up" for a Super Bridge in Georgia, withstanding Gale-Force Winds of Level 9 and Temperatures as Low as -20°C

TBILISI, Georgia, Aug. 17, 2026 /PRNewswire/ -- China has further upgraded technical standards for overseas bridge construction, and a "Belt and Road" super arch bridge has completed a comprehensive verification of its wind resistance performance. The B3 Arch Bridge, a key control project on Georgia's North-South Corridor Road Section, has successfully completed a full series of wind tunnel tests covering critical construction conditions and the completed-bridge state at the National Key Laboratory of Bridge Engineering Safety and Resilience of Hunan University. As the concrete arch bridge with the longest span in the Caucasus region and the fourth-longest span of its kind in the world, the bridge has innovatively completed field-based verification of wind resistance throughout its entire life cycle, from construction to operation. This effectively addresses the technical challenges posed by extreme environmental conditions at the bridge site, including Level-9 winds, temperatures as low as -20°C, and snow accumulation of up to 2 meters, providing solid technical support for the left-side main arch closure scheduled for 2026 and the bridge's long-term safe and stable operation.

It is understood that the B3 Arch Bridge of the Georgia North-South Corridor Road Section, constructed by China Railway 23rd Bureau Group Co., Ltd., is an upper-deck reinforced concrete bridge with twin box-section arch ribs. The bridge has a total length of 437.875 meters, a main arch clear span of 286 meters, and a vertical clearance of 164 meters from the bridge deck to the valley bottom. It is being constructed using a cable-stayed tie-back system and cantilever casting with form travelers. The bridge is a key control project of the Georgia North-South Corridor Road Project. Located in a mountainous canyon, the bridge site is subject to extremely harsh environmental conditions. The regional extreme wind speed reaches Level 9, the minimum winter temperature drops to -20°C, and the maximum snow depth reaches 2 meters. Such complex and extreme climatic conditions pose stringent challenges to the safety and stability of the bridge during both construction and operation.

Previously, the project had completed wind tunnel testing for the bridge under the maximum cantilever construction condition, addressing the risk of strong winds during the most vulnerable stage of construction. The current test focused on two key areas to address gaps in technical risk control. First, a full-bridge model wind tunnel test was conducted to verify the bridge's long-term wind resistance performance during operation and establish a closed-loop safety verification system covering the entire cycle of the project. Second, with particular focus on the critical left-side arch ring closure scheduled for 2026, a special test was carried out for the high-risk condition of asymmetric construction of the left and right arch ribs. During this stage, the bridge structure is subjected to unbalanced forces. Combined with canyon turbulence and aerodynamic interference between the twin arches, the construction risks are particularly high. By accurately simulating the actual wind field through a physical model, the technical team comprehensively investigated and eliminated potential wind-induced safety hazards.

The current tests were conducted in strict accordance with the FIDIC contract provisions and European engineering standards, ensuring the reliability and authority of the measured results. The test results show that, after completion, the bridge will be capable of withstanding extreme winds far exceeding those of a once-in-100-years event and will fully satisfy operational safety requirements. During the asymmetric arch-ring closure construction in 2026, wind-induced vibration and deformation of the bridge, as well as structural stresses, will remain within safe and controllable limits, with all indicators meeting the requirements of the contract and applicable technical specifications.

The project has integrated the results of the two rounds of wind tunnel tests and optimized its wind-resistance and vibration-control construction procedures and on-site control measures. A comprehensive wind-resistance safety system covering the entire process of construction, arch closure, and operation has thus been established. Compared with the theoretical calculation and assessment methods commonly used for similar overseas projects, this project adopts physical model testing under all relevant conditions, significantly improving the accuracy of the safety assessment and achieving an upgrade in wind-resistance technology for long-span arch bridges.

As a landmark overseas infrastructure project under the Belt and Road, the project has leveraged top-tier domestic scientific research capabilities to develop and apply mature and advanced empirical technologies for bridge wind resistance. It has also established a comprehensive construction solution adapted to the complex cold-climate canyon environment and compliant with European and international construction standards.

Next, the project team of China Railway 23rd Bureau Group Co., Ltd. will implement all relevant safety control measures, steadily advance construction, and make every effort to ensure the timely completion of the left-side arch-ring closure milestone in 2026, further demonstrating the technological strength of China's infrastructure construction and its international project delivery capabilities.

Source: China Railway 23rd Bureau Group Co., Ltd.