Sensor layout must be evaluated to enable the capture of adequate information for integrity analysis, while keeping sensor numbers as small as possible. The research challenge of this case study of two long-span cable-stayed bridges is to optimise monitored sections, sensor placement, sampling frequency and type selection. The structural features and their structural health monitoring (SHM) systems are introduced for the two bridges. Next, the critical sections (i.e., maximum sagging, hogging girder and tower sections) are determined through finite-element modelling. Data features and patterns of thermal sensors, anemometers and deflection sensors are analysed to give feedback to the SHM design. The novel contribution of this study includes various findings: monitoring temperature gradients along the thickness of girder soffits, deck chords, girder bottom chords and cable sections is a low priority as they are small in magnitude. For temperature data, 10 min readings to obtain a datum are adequate for further analysis. Anemometers with a minimum frequency of 10 Hz are recommended at two critical locations: deck level and tower top level. Global positioning is advised to monitor large girder deflections with a minimum frequency of 1 Hz. The connected pipe system is recommended for those bridges with relatively small deflection amplitudes.
Xu et al. (Wed,) studied this question.