UAV-Based Remote Sensing Applications for Bridge Condition Assessment

A systematic review of UAV-based bridge condition assessment organised by sensor: visual imaging, infrared thermography, LiDAR and other sensors. It analyses 65 papers from 2000-2020, screened from about 700 hits, and covers performance factors (equipment, pilots, bridge type, weather, regulation), flight planning, data analysis and cost. Reported costs vary widely, including a case where UAV inspection was more expensive. Challenges include the lack of standard procedures, wind and rain, battery limits and GPS loss under decks.

Key findings

• 65 papers analysed (2000-2020); about 80% from the last three years
• One study: UAV inspection of fracture-critical members cost about 130% more than an under-bridge truck because it took longer
• Other studies: about 10% cheaper, 66% cost savings, or 46% faster and 61% cheaper
• Thermography about 9% less accurate than hammer sounding for delamination, but 6-8% more accurate than half-cell potential
• Wind limit around 24 km/h recommended for safe operation

Limitations

• Last part of the page (about 15% of text) not read
• Cost figures come from heterogeneous individual studies
• GPR not reviewed as a UAV payload