Jeffery Roberts, a structural engineer for the Corps’ Tulsa District, has been involved in various aspects of engineering his entire career. Working for Hewlett Packard for 12 years as a manufacturing process engineer, R&D engineer, and firmware engineer, his career path moved on to Xerox, further developing his expertise as a senior firmware engineer. After seven years with Xerox, Roberts pursued his long-time interest in structural engineering, focusing his efforts in bridge engineering. He has since completed his academic requirements in the doctoral program at Portland State University.
After starting with the Tulsa District, Roberts inquired within ERDC about the possibility of remotely working with a researcher in order to complete his dissertation. He spoke with ERDC Human Capital Director Dr. Gary Anderton, who told him about the ERDC University (ERDC-Up Program. Since his acceptance into the program, Roberts has focused his efforts on an existing research program sponsored by Mentor Dr. Matthew Smith, ERDC Coastal and Hydraulics Laboratory. The research is aimed at estimating the limitations of methods USACE currently uses to classify the condition of bridges. Presently USACE is responsible for almost 900 bridges, with more than 40 percent being fracture-critical. The current process is based on subjective assessments in the classification process. Research is presently being directed toward replacing subjective with objective assessments in the classification process, greatly improving the effectiveness of the bridge inspection program.
Roberts’ research will aid in evaluating the failure modes of multi-girder bridges by identifying specific objective parameters that affect structural reliability that could be collected by field inspectors. These parameters include cracking, staining, delamination and spalling of reinforced concrete bridge elements. Roberts also assisted in selecting a USACE-owned bridge that is being used to develop the framework and will be used as a reference. Initial efforts are focused on identifying geometric and material properties and all failure modes associated with the sample bridge in accordance with the Load and Resistance Factor Design. After failure modes were identified and a bridge selected, Roberts focused on evaluating the flexure failure mode to determine how location and extent of deterioration affected the reliability of the bridge.
He investigated the application of Bayesian Networks, a type of statistical model, for bridge asset management. His goal was to develop tools and techniques for a quantitative and probabilistic approach to determine bridge reliability. The long-term objective of this work is for the framework to be extended to any type of USACE asset. Of particular interest is using the framework with navigation locks, which use steel and concrete materials in relatively complex configurations. In general, though, this method should be able to be used with any structure.
The ERDC-U program allowed Jeff the opportunity to focus on learning about Bayesian networks, structural reliability theory, and how these concepts can be used within an asset management framework. He has gained knowledge on new subject matter and made valuable contacts with subject matter experts.
Roberts said he would “definitely” recommend the ERDC-U program to others in his district. “ERDC-U is a very unique opportunity for USACE employees to be immersed in a focused environment with subject matter experts. It is the perfect environment to enhance or learn new skills.”