Structural Health Monitoring Pilot Project - 1A - Iowa Falls... · Structural Health Monitoring...
Transcript of Structural Health Monitoring Pilot Project - 1A - Iowa Falls... · Structural Health Monitoring...
Structural Health MonitoringPilot Project
Iowa Falls Arch Bridge
MAASTO 2013Milwaukee, WI
July 16-19, 2013
Background
• Iowa DOT investigations of new High Performance Materials, Design Concepts, Construction Methods and Maintenance Methods.
• Develop a Structural Health Monitoring (SHM) system to determine real time structural and continuous condition of a bridge.
Concept
• Develop a Structural Health Monitoring System that can be used on critical structures.
• Demonstrate the technology on a smaller project.
• Iowa Falls arch bridge was identified due to bridge type similarities and complexities.
Existing Bridge
• Built in 1928
• 255-foot open spandrel concrete arch
Constraints and Constructability Issues• Historic church
– NW corner of bridge– Listed on the National Register of Historic Places
Photo by: iafalls.com
Constraints and Constructability Issues• Dam
– Maintain water level for power generation
Foundation Issues• Existing bridge undermining
Demolition Concerns
Constructed a system to protect the sanitary sewer lines
Demolished the bridge using the causeway
Monitoring Components
• Environmental
• Structural
• Construction
• Security
Environmental
• Alert for high wind events
• More efficient use of de-icing chemicals thus reducing bridge deterioration and impact to environment
• Increase public safety due to timely application
• Wind speed and direction
• Bridge deck potential icing conditions
• Temperature and humidity
Structural
• Apply preventive maintenance based on early detection of deterioration
• Prevent failure of critical members • Use in updating rating and permitting• Detection of heavy loads• Fatigue life assessment
• Corrosion potential in deck, substructure at expansion joints, and micro piles and concrete anchors foundation
• Arch and hanger forces
• Collect data from bridge superstructure
Construction
• Monitor erection stresses during critical construction stages
• Work with contractors to make timely adjustments
• Avoid structural damage due to overstress during erection
Security
• Monitor activities on bridge
• Monitor stresses in hangers in case of breaks
• Send alerts of possible threats
Infrared Camera• Detects both people and fire
• Mounted on utility pole SW of bridge
• “Sees” IR spectrum rather than visible light
IR camera – research team detection
Data Collection
• Data sent via internet connection to InTrans servers once per minute (fast read) and once per 10 minutes (slow read)
• Cameras viewable real-timeIowa Falls
Data Collection PC
BECData Storage
ArrayFTP
Synchronization
MS SQL Database
Video
InternetAnemometer
33 ft
Satellite
Transceiver
UPS
Data
Storage
Server10 ft
Modem
Wireless
Router
CR9000C
WAP
(Bridge)
B E C
Remote Monitoring
Web Interface
Select Sensor to View Real-time Data
Real-time Video
Questions?
Norm McDonald
Director, Office of Bridges and Structures
Iowa Department of Transportation