Project Background
Long-span cable-stayed bridges are critical nodes of urban river-crossing corridors and sea-crossing projects. The stress states of their pylons, main girders and stay cables vary continuously under vehicle loads, wind loads and temperature fields. Conventional manual inspection is infrequent and produces fragmented data, making it difficult to capture the structure's true response under extreme conditions.
This platform targets extra-large cable-stayed bridges with main spans exceeding 500 m, building an end-to-end online monitoring chain from sensing to decision-making.
Monitoring Scope
Structural safety monitoring
- Strain monitoring at critical girder sections (FBG strain gauges + vibrating-wire strain gauges as dual redundancy)
- Pylon settlement and inclination (hydrostatic leveling system + inclinometers)
- Real-time stay cable force monitoring (magnetic flux sensors / pressure ring sensors)
- Dynamic mid-span deflection monitoring of the main girder (extensometer + GNSS dual mode)
- Bearing compression and rotation displacement
Environmental and load monitoring
- Wind speed, direction and pressure time histories (ultrasonic anemometers)
- Ambient and structural temperature fields (distributed fiber-optic temperature sensing + point temperature sensors)
- Traffic volume statistics (video AI + weigh-in-motion WIM)
Early warning and assessment
- Multi-tier warning thresholds (blue / yellow / orange / red, each with a corresponding response mechanism)
- AI anomaly recognition with linked camera evidence capture
- Automatic generation of structural load-bearing capacity assessment reports
Key Metrics
- Monitoring points: 2,400+
- Data acquisition rate: up to 100 Hz (vibration monitoring channels)
- Warning response time: <1 minute
- System availability: 99.9%
- Anomaly warning accuracy: >85% verified in the project
Technical Architecture
- Sensing layer: multi-source fusion of FBG sensors + vibrating-wire sensors + GNSS + video AI
- Transmission layer: industrial fiber-optic ring network + 5G dual-channel redundancy
- Processing layer: cloud-edge collaboration, with edge-side preprocessing and filtering, plus cloud AI analysis and real-time digital twin simulation
- Application layer: B/S architecture monitoring dashboard + mobile alert push notifications + WebService integration with the owner's existing systems
Implementation Highlights
During the construction phase, monitoring must focus on the traveling formwork's movement posture, temporary support deformation, and the effect of concrete shrinkage and creep on initial stress. These data also serve as the starting point of the baseline database for later operation and maintenance, and installation accuracy directly affects the usability of long-term data.