Supporting a technical partner, Mote was engaged to measure the vertical deflection and crack opening between adjacent Double Hollow Core (DHC) bridge beams.
Short term condition assessment monitoring
The information was required to assess transverse connectivity between beams and the potential degradation of load carrying capacity of the bridge.
Deflections and joint opening during static loading and dynamic loading using test vehicles and normal traffic usage were assess using non-contact laser triangulation displacement sensors (1.5 microns resolution, sampling frequency 100 Hz and optical digital displacement sensors (0.5 micron resolution, 1 mS sample period).
The proximity of the test truck to each joint was assessed using a mid-range laser distance sensor (0.1mm resolution, 12 m range).
Maximum deflections and crack openings were quickly assessed on multiple joints given the non-contact measurement system and compared with frame structural models to assess the joint failure conditions.