Civil and Environmental Engineering Seminar – Current Status of America’s Highway Bridges and Future Trends – Dr. David Liu

There are more than 617,000 bridges across the United States. Currently, 42% of all bridges are at least 50 years old, and 46,154 or 7.5% of the nation’s bridges are considered structurally deficient, meaning they are in “poor” condition. As the average age of America’s bridges approaches 44 years, the number of structurally deficient bridges has continued to increase. Unfortunately, the rate of improvements has not been keeping pace. This presentation will address the current state of US highway bridges, the importance of redundancy, durability, bridge information modeling (BrIM), 3-D drawings, innovations in bridge inspection and accelerated bridge construction (ABC). For ABC, different ABC approaches such as the use of prefabricated bridge elements and systems (PBES), self-propelled modular transporter (SPMT), lateral sliding, and new materials, e.g., ultra high performance concrete (UHPC), will be presented.

Dr. Liu is a Bridge Engineer in Chicago. Previously, he worked for Parsons as a principal bridge engineer, and TranSystems as the bridge department manager and project manager. He was also the lead structural engineer for the $450 million Jane Byrne (Circle) Interchange Project (a joint venture with AECOM) in Chicago, Illinois.
Dr. Liu has a B.S. and M.S. from South China University of Technology, China, and Ph.D. from Clarkson University, Potsdam, New York. He is a registered structural engineer in Illinois and a registered professional engineer in eight states. Dr. Liu has over 30 technical papers that have been published, presented or accepted by
ASCE Journals and periodicals. He has also given a number of seminars and talks at universities and professional conferences.