Continuous monitoring of a long-span cable-stayed timber bridge

Abstract

This paper presents the system structure and results of a continuous monitoring system that is applied on the longest span cable-stayed timber bridge in Scandinavia. We have installed a combined global navigation satellite and environmental monitoring system with temperature, wind speed, wind direction and humidity observations on the bridge and apply a holistic approach to investigate the environmental effects on the bridge. Our results show that temperature changes and total deformation of the timber bridge have strong relation to the thermal expansion coefficient of the steel cables. However, the measured total deformation of the timber bridge is still within the design limits according to European standards which validate the design criteria. The relations between transverse wind speed and transverse deformation of the bridge were experimentally investigated, but no direct relations were found that imperils the structural integrity.