Cost–Benefit Analysis of Bridge Health Monitoring: The Case of Tied-Arch Bridge

– Nowadays, the structural health and durability of civil infrastructure are fundamental issues in modern engineering, especially in developing countries in Latin America. This article presents a cost-benefit analysis of implementing a high-quality Structural Health Monitoring (SHM) system on a tied-arch bridge in Lima, Peru. The system consists of MonStr triaxial acceleration sensors, a Power over Ethernet (PoE) data network, and real-time data processing via a remote interface. The placement of four accelerometers was strategically planned based on modal analysis, dynamic behavior, and the structural response of the bridge. A numerical analysis of the bridge was performed using SAP software. Furthermore, the economic evaluation demonstrates that, while the initial investment is higher than that of conventional, low-cost inspection methods, the SHM system offers substantial long-term benefits. These include early detection of structural damage, extension of the structure's service life, and efficient maintenance planning. A comparative analysis, supported by recent scientific literature, demonstrates a positive return on investment (ROI) and a high value of information (VoI) throughout the bridge's operational lifespan. The cost of implementing the continuous monitoring system represents only 0.21% of the total construction cost, a significant factor to consider in the long term and throughout the bridge's service life. Therefore, the results support the adoption of Bridge Monitoring Systems (BHM) in urban bridges exposed to dynamic loads and seismic activity, particularly when the goal is to implement predictive maintenance and mitigate structural risks.