Assessment of the condition and performance of long span bridges using automated monitoring systems – optimising inspection and maintenance efforts

Inspection and maintenance of long span bridges, and of their mechanical components such as bearings and expansion joints, is critically important in ensuring long-term safety and performance and in minimising life-cycle costs. But if done manually, it can be a time-consuming and costly exercise, and thus often does not get the attention it deserves. Furthermore, manual inspections are carried out only periodically, with perhaps many months, or even years, elapsing between inspections. Such a delay in recognising the need to address any deterioration can have a serious impact on the bridge and its users, with far higher costs for repair or replacement, and disruption to traffic while such works are carried out. And yet more significantly in many cases, delayed awareness of deterioration or unexpected events may compromise user safety. Automated monitoring systems offer solutions to such problems in many cases. They are fast, efficient and highly accurate, and the immediate notification they can provide of unexpected events such as earthquakes, extreme weather, or ground settlement or slippage can enable the responsible authorities to quickly take appropriate action.

This paper describes the role that can be played by modern remote structural health systems in the inspection and maintenance of long span bridges, and illustrates these with reference to a number of current bridge monitoring projects.