Investigation and Analysis of the New Walterdale Bridge to Develop a Structural Health Monitoring System

Abstract

Structural Health Monitoring (SHM), a technique of applying sensors to a structure to monitor for damage, is becoming a good preventative and management application to use on new and existing infrastructure, such as bridges, in order to effectively monitor and evaluate their performance under various loading scenarios. The application of SHM can be a cost-effective solution, as it can decrease the cost of maintenance by allowing engineers to confirm their design assumptions and make well informed decisions on the extent of damage present. In order to do so, however, it is necessary to understand the actual behaviour of the structure and how the behaviour can best be measured. In Edmonton, Alberta, Canada, the century-old Walterdale Bridge has reached the end of its service life and is being replaced by a new bridge. The new Walterdale Bridge is a thrust-arch bridge that has been designed to meet the functional and aesthetic needs of users. It will be the first of its kind in Edmonton. In this project, a preliminary finite element (FE) model of the new bridge was modified and analyzed under design and predicted loading. A sensor layout was then developed that incorporates 199 sensors. Preliminary investigation into the accelerometer layout plan was conducted using the Complex Mode Indicator Function (CMIF) modal identification algorithm. This investigation found that global damage, such as a change in boundary conditions, can be detected more easily than local damage simulations, which would be expected using global measurement techniques. The ability to detect local damage was dependent on the severity of damage present and the locations of the sensors on the structure. As this damage detection analysis is preliminary, the ability to detect damage may change in further studies that incorporate other algorithms and measurement types.