Date of Award

Spring 2013

Project Type


Program or Major

Civil Engineering

Degree Name

Master of Science

First Advisor

Erin Bell


According to the American Society of Civil Engineers more than one in nine bridges is considered to be structurally deficient (ASCE, 2013). This ranking is based on load ratings from visual inspections which aim to assess the condition of a bridge but are inherently subjective. It is vital to determine the true structural health of bridges in order to ensure efficient allocation of limited resources for critical infrastructure elements. The purpose of this research is to develop digital image correlation into a tool that bridge inspectors can rapidly deploy as part of In-Depth Bridge Inspection for an objective assessment of bridge condition.

Digital image correlation (DIC) can be used to measure deflections of bridge girders. In June 2012, digital cameras were used during a pseudo-static load test of the Bagdad Road Bridge in Durham, NH, to capture bridge response. The deflections from this load test were used to calibrate a structural model to determine the impact of boundary conditions on the continuous action of the bridge. This research also assesses the accuracy and limitations of DIC and the value of using deflections to determine load distribution factors to more accurately load rate a bridge and calibrate an analytical model that is more representative of the bridge's behavior. In addition, a profile of girder deflections creates a metric for assessing bridge health in the future.