Strain, movement and dynamic response across the structure

Bridges respond every day to traffic, wind, temperature and occasionally seismic activity. Monitoring records that response so engineers can separate everyday behaviour from longer-term change.

• Key structural elements: strain under different load conditions.
• Beams and supports: displacement, tilt and subsidence.
• Dynamic response: acceleration and vibration from traffic, wind and seismic activity.
• Materials: temperature-related movement, moisture in concrete and steel, and corrosion-related changes in metal components.
• Cracking: crack formation and growth, and acoustic emission associated with damage.

Monitoring data can sit alongside inspection findings in the same asset record.

• Strain gauges: strain in key structural elements under load.
• Displacement and laser sensors: movement of beams and supports, with laser sensors for precise displacement.
• Tiltmeters: tilting and subsidence of the structure.
• Accelerometers and vibration sensors: dynamic loads from traffic, wind and seismic activity.
• Temperature and humidity sensors: thermal expansion and moisture in concrete and steel.
• Crack and acoustic emission sensors: crack growth and associated high-frequency signals.
• Pressure sensors: pressure on bridge components and foundations.
• Electromagnetic sensors: magnetic field changes associated with corrosion in metal components.
• Gas and light sensors: hazardous-gas presence and ambient light or bridge-lighting conditions, where required.