AWARD OF EXCELLENCE: Transportation Category

Rehabilitation of Historical Arch Railway Bridge

Klong Toey, Bangkok, Thailand

Submitted by Nontri Co. Ltd.

The reinforced concrete arched bridge in Bangkok was built 50 years ago. Its span length was 40 m (130 ft) and its width was 4.6 m (15 ft) The railway bridge facilitated transportation of crude oil to the local oil refinery. Before repair and restoration processes, the bridge had been seriously damaged from corrosion and overloading and cracks could be easily observed throughout the structure. The bridge was registered as a national heritage and the owner, State Railway of Thailand, wished to maintain its architectural aspect. The bridge was also required to be open for oil transportation while it was under repairing processes. There were many constraints in the repair and restoration processes, such as no disturbance to the oil transportation, high security standards due to susceptibility of oil, no alteration of its architectural aspect, and restoration needed to be completed in a limited time.

In the aspect of structural strengthening, due to increasing of live load for more than 40% from design live load, the structure had to be strengthened in the way that it could carry a new maximum load safely. In this project, Carbon Fiber Composites System was used to strengthen the bridge due to its lightness and high strength, resistance to corrosion, and ability to preserve the original architectural appearance. Flexural strength and shearing capacity of each part of the structure were increased. From results obtained by testing of the bridge after strengthening, it was found that structural performance of the bridge increased significantly.