Inspection and Load Rating of Post-Tensioned Segmental Bridges

AbstractThis presentation provides an overview on the approach to analyze existing infrastructures using NDT inspection techniques and Finite Element Analysis.The case study covers the analysis of the long-term behavior of Post-Tensioned concrete segmental bridges part of an Illinois Tollway interchange. Opened in 1989, the interchange connecting the Veterans Memorial Tollway (I-355) and Reagan Memorial Tollway (I-88) in Downers Grove includes four post-tensioned segmental concrete box girder bridges with length ranging from 558 feet to more than 2,000 feet on horizontally curved alignments. The Illinois Tollway wanted to evaluate the current structural capacity under various lane configurations and so required to perform full in-depth inspection and material testing to assess the condition of the superstructure and substructure post-tensioned elements. The structures were modeled taking into account current condition and the original post-tensioning sequence for load rating purposes. The results show how these structures' behavior is very close to what predicted.This detailed study gave the Tollway the ability to better plan how to manage and maintain these structures in the years to come.

BioSalvatore Di Bernardo has over 27 years of experience in concept study, design and construction management for bridges and other transportation related structures including several award winning and signature bridge projects. His structural design experience includes cable-stayed structures, truss bridges, arch bridges, pre-stressed and post-tensioned concrete and steel bridges, long span plate girder, curved steel plate girder, complex retaining walls, and complex erection plans. During his career in the United States and in Europe he has presented research related to his work on signature bridges, bridge asset management and advanced structural analysis of complex bridges at various national and international conferences. Salvatore's experience with bridges include Program Management for bridge inspection and asset management for governmental agencies. Mr. Di Bernardo is actively involved in national and international professional organizations, a Past President and Board of Director member of the Structural Engineers Association of Illinois and a member of the State of Illinois Structural Engineering Licensing Board. He has been involved with the Design- Build Committee of the Illinois Road and Transportation Builder Association and other technical commissions. He is a fellow member of the International Association of Bridge and Structural Engineers. He is licensed in various US States, the UK and Italy.