Instrumentation, Digital Image Correlation, and Modeling to Monitor Bridge Behavior and Condition Assessment

Research Assistants: David Gaylord, P.E., Adam Goudreau and Daniel WhitePrinciple Investigator: Erin Santini Bell, Ph.D., P.E.

Structural Health Monitoring (SHM) uses a blend of instrumentationand science that has the potential to increase the efficiency ofbridge asset management. This research aimed to facilitate andaccelerate future SHM research projects in New Hampshire througheasily implemented technology. Protocols were developed andinstrumentation was deployed at the Bagdad Road over US Route 4Bridge in Durham NH (NH Bridge 114/128).

Digital Image Correlation (DIC) at Bagdad Road

DIC is an optical method for trackingchanges from one image to another.For this project, images were recordedduring an event, analyzed for pixelmovement and displacements, andstrain was calculated.

Bonded foil strain gauges andthermocouples were installed on twobeams. Readings collected undertypical traffic loads from the sensorswere used to determine neutral axislocations in the steel\concretecomposite girders.

The effectiveness of GoPro® cameras asDIC sensors for 2D and 3D strainmeasurement was investigated during thisproject in the laboratory and at theBagdad Road Bridge.

The field results correlate to the strainmeasurement collected with the straingauges.

Project Number: NHDOT 15680L

Comparing Strain Gauge to DICStrain Gauge Installation at Bagdad Road