UAS have transformed bridge inspections by providing high-resolution imaging, thermal data, and 3D modeling capabilities. They eliminate the need for heavy equipment, scaffolding, or lane closures, and reduce risk to human inspectors.
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ections Using Drones
Pre-Inspection Planning
Site Assessment: Conduct a preliminary assessment of the bridge to determine its structure, access points, and surrounding environment.
Regulatory Compliance:
Obtain necessary waivers or permissions from the FAA, especially if the bridge is in controlled airspace.
Ensure compliance with Part 107 regulations (or BVLOS waivers if needed).
Mission Planning:
Identify the areas of interest (deck, joints, supports, cables, etc.).
Program flight paths and waypoints to ensure comprehensive coverage.
Define inspection goals (e.g., visual damage, thermal irregularities, 3D modeling).
Drone Selection and Sensor Configuration
Drone Type: Use industrial-grade drones such as the DJI Matrice series, Skydio, or Freefly Alta.
Payload Options:
High-resolution cameras (20MP or more).
Thermal sensors for detecting heat anomalies.
LiDAR for 3D modeling of bridge surfaces.
Zoom cameras for close-up inspections of hard-to-reach areas.
On-Site Preparation
Conduct pre-flight checks (battery levels, sensor calibration, weather conditions).
Establish a safe operating area.
Set up GPS references or RTK systems for enhanced accuracy.
Data Collection
Fly predetermined routes to capture high-resolution images or video of critical components.
Utilize orbit and waypoint modes for thorough scans.
Inspect areas such as the deck, supports, cables, joints, and bearings.
Post-Processing
Use photogrammetry software (Pix4D, DroneDeploy) to create 2D maps or 3D models.
Analyze thermal images for heat-related anomalies.
Compile findings into a comprehensive report with visuals and data points.
Reporting and Analysis
Compare collected data against engineering standards.
Highlight damage, corrosion, cracks, and misalignments.
Provide actionable recommendations for maintenance or repair.
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Deck and Pavement
Inspect for cracking, spalling, and delamination.
Assess skid resistance and surface integrity.
Superstructure
Inspect girders, beams, and trusses for structural integrity.
Check connections, welds, and bolted joints.
Substructure
Evaluate piers, columns, and abutments for signs of scour, cracking, or settlement.
Bearings and Expansion Joints
Look for wear, corrosion, and misalignment in these critical load transfer components.
Cables (for suspension and cable-stayed bridges)
Assess tension cables for wear, corrosion, and strand damage.
Underside of the Bridge
Inspect soffits, arches, and hard-to-reach areas where traditional inspections may be challenging.
Drainage Systems
Check for blockages or inadequate water flow that can lead to structural issues.
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Increased Safety: Eliminates the need for inspectors to access dangerous locations.
Cost Efficiency: Reduces equipment and labor costs by minimizing the use of scaffolding, lifts, or rope access.
Time Savings: Drones can inspect large bridges in hours rather than days.
Enhanced Accuracy: High-resolution imagery and 3D models improve defect detection.
Data Archiving: Captured data can be stored and referenced for future inspections.