SHM approach for cable-stayed bridges based on stay load cell measurements

This study proposes a novel methodology for monitoring cable-stayed bridges by using measurements of load cells installed on bridge stays to capture both static and dynamic responses of the structure. The reconstruction of mode shapes based on force measurements aims to reduce the number of sensors while maintaining full diagnostic capabilities. In this work, the differences between force-based and displacement-based modal profiles have been investigated with a parametric analysis highlighting differences between force and displacement mode shapes across various bridge configurations, providing reference guidelines for harp and fan layouts. Moreover, to optimize both the number and position of instrumented stays, an advanced sensor placement strategy is introduced. The full methodology is validated on a real cable-stayed bridge in central Italy, supported by experimental tests and finite element modelling. Results demonstrate that this load-cell-based monitoring framework offers a comprehensive solution for structural health assessment of cable-stayed bridges with a limited number and typology of sensors.