Monitoring system for execution control applied to a steel arch footbridge

Abstract

The construction of innovative structural systems and the use of unconventional erection procedures need refined tools to assess the phased behaviour and control the site operations. The combination of a specific monitoring system with a detailed numerical model constitutes an adequate tool to assist bridge construction. The application of this tool to the construction of a 275 metre long footbridge, displaying innovative structural characteristics, is discussed in the paper. A dedicated monitoring system, including strain gauges and thermal sensors was implemented to monitor critical cross sections during both the construction process and in-service. A detailed numerical model was developed and applied for the prediction of the phased construction behaviour and to help in the interpretation of the experimental measurements. In this paper the focus is driven to the aspects related with the installation of the monitoring system, the implementation of the bridge model and the discussion of the results obtained during the construction stages, namely the removal of the propping system. The unusual but direct construction procedure used to build the footbridge greatly relied on the monitoring predictions and continuous assessment to control and reduce the inherent risks of the adopted construction process.