A Combined Structural Health Monitoring and Weigh-in-Motion System for Railway Bridges

Many bridges in the world’s transport infrastructure are old and have deteriorated over time. The solution to this problem is to either repair or replace a bridge or to establish its safety and maintain it in service. It is generally very costly to repair or replace a bridge. With reduced maintenance budgets there is an increasing interest in maintaining these old bridges in service for longer by using probabilistic methods to prove that they are safe. Bridge safety is assessed based on (i) the loading which it will experience in service and (ii) the resistance of the structure. Improved knowledge of loading and resistance allows a more accurate assessment of whether a bridge is safe to remain in service without the requirement for expensive repair or replacement strategies. A system that combines Structural Health Monitoring (SHM) with Bridge Weigh-in-Motion (B-WIM) can provide bridge owners with information about the true safety of a bridge structure. The B-WIM part of this system is a method of collecting traffic load data using measurements taken from the bridge as vehicles cross it (WAVE, 2001) (WAVE, 2001) (WAVE, 2001) (WAVE, 2001). Hence the traffic data is current and specific to the bridge in question. The SHM part of this system continuously monitors the bridge for new damage and assesses its remaining resistance.