Structural Health Monitoring of Bridge Structures as a Response to Uncontrolled Loading Using Pseudo-Static Measurements

This thesis is focused on the structural health monitoring (SHM) of bridge infrastructure, notably drawing on emerging research of rotation as a damage sensitive parameter. A Bridge Weigh-in-Motion (B-WIM) system using rotation measurements is demonstrated to be damage sensitive to localised loss of stiffness in the bridge deck. On a damaged bridge the rotation B-WIM results will deviate from those predicted by a traditional strain-based B-WIM system, indicating the presence of damage and, with additional sensors, the approximate location. On wide, statically indeterminate bridges, when there is a loss of stiffness in a section of the bridge, a portion of the load will redistribute along alternative load paths in the structure, indicating the presence of damage. In addition to this, changes in the measured rotation, or ‘pitch’ signal, of a crossing vehicle are used in this thesis as an indicator of the presence of foundation scour in a bridge. Existing literature can detect damage by monitoring the bridge influence line of a damage sensitive parameter, such as rotation, for changes indicative of damage. This approach is expanded by introducing a new method which can extract a damage sensitive influence line from a partial measurement signal, addressing complications such as unknown velocity, step changes in velocity, and changing locomotives.