Gamma prediction models for long-term creep deformations of prestressed concrete bridges

Abstract

For long-span bridges as well as statically indeterminate frame structures it is essential to implement efficient and realistic prediction models for the long-term processes of concrete creep, shrinkage, and steel relaxation. In order to systematically study the main influential factors in bridge deflection measurements a probabilistic analysis can be performed. Due to the associated computational costs such investigations are limited. The predictions based on the highly scattered input parameters are associated with uncertainties. There is interest in alternative prediction models decoupled from complex analytical and computationally expensive numerical models, using measured structural responses. A gamma process is an example of such an alternative method. This process is suitable for capturing evolving structural response quantities and deterioration mechanisms like crack propagation, corrosion, creep, and shrinkage, as reported in Ohadi and Micic (2011). The objective of this paper is to illustrate the use of gamma process approaches for the prediction of the creep and shrinkage performance of prestressed concrete bridges. The presented approaches incorporate uncertainties and make predictions more reliable with the help of structural health monitoring (SHM) data. The creep-shrinkage response of a prestressed box girder bridge serves for the calibration and evaluation of the considered gamma process approaches.

Keywords:

• realistic creep model
• gamma process
• statically indeterminate structures
• probability
• box girder bridges

Additional information

Notes on contributors

Alfred Strauss

Alfred STRAUSS. Assoc. Prof., born 1968 studied Civil Engineering at the Technical University of Vienna. He received a Full Professor Qualification (Scientific Habilitation) from the University in 2013. His education includes a 5yr Degree in Civil Engineering with honours from the Technical University of Vienna (1997), a PhD in Stochastic-Probabilistic Engineering from University of Natural Resources and Life Sciences (2004). He is an experienced researcher and consultant engineer for advanced structural analysis problems related to bridges, roof systems, and off shore structures. He has authored/co-authored more than 5 books, over 120 articles in archival journals, and many papers in conference proceedings. His main research areas include computational analysis of concrete structures, structural reliability, structural optimization, life-cycle engineering and artificial intelligence in structural engineering.

Roman Wan-Wendner

Roman WAN-WENDNER. Dr. habil. Roman Wan-Wendner, born 1983 is a senior researcher and director of the Christian Doppler Laboratory on Life-Cycle Robustness of Fastening Systems at the University of Natural Resources and Life Sciences in Vienna Austria, where he also received, his Master’s degree in Civil Engineering and his PhD, both with highest distinction. After 2,5-years as Research Associate at Northwestern University, Evanston, IL, USA, he returned to Vienna and received his Habilitation in 2015. Dr. Wan-Wendner is an internationally established researcher in the field of concrete creep and fracture mechanics. Since 2016 he serves as vice-chair of the ACI technical committees 209 and 446. His main research interests are the mechanics of aging infrastructure materials with focus on concrete and other materials critical to the life-time performance of fastening systems.

Anja Vidovic

Anja VIDOVIC. Ms Vidovic received her MSc degree in Civil Engineering from Faculty of Civil Engineering, University of Rijeka in Croatia in 2014. She is currently studying as a PhD student in the Institute of Structural Engineering at University of Natural Resources and Life Sciences Vienna, Austria. Her research interests are life cycle assessment and maintenance plans of existing reinforced concrete bridges and durability of protection and repair systems of concrete structures.

Ivan Zambon

Ivan ZAMBON. Ivan Zambon is a PhD student in the Department of Civil Engineering and Natural Hazards at University of Natural Resources and Life Sciences, Vienna. He received his MS from Faculty of Civil Engineering at University of Rijeka in 2014. His research interests are assessment and evaluation of existing structures with the emphasis on material durability and deterioration mechanisms.

Qiang Yu

Qiang YU. Qiang Yu is an Assistant Professor at the University of Pittsburgh. He is a member of ACI committee 446, Fracture Mechanics of Concrete, and a member of ACI Committee 209, Creep and Shrinkage in Concrete. His research interests include the fracture behavior and long-term performance of reinforced concrete structures.

Dan M. Frangopol

Dan M. FRANGOPOL. Dr is the inaugural holder of the Fazlur R. Khan Endowed Chair of Structural Engineering and Architecture at Lehigh University. Before joining Lehigh University in 2006, he was Professor of Civil Engineering at the University of Colorado at Boulder, where he is now Professor Emeritus. He is recognized as a leader in the field of life-cycle engineering of civil and marine structures. He is the Founding President of the International Associations for Bridge Maintenance and Safety (IABMAS) and Life-Cycle Civil Engineering (IALCCE). He has authored/co-authored 2 books, 40 book chapters, and over 350 articles in archival journals including 9 prize winning papers. He is the Founding Editor of Structure and Infrastructure Engineering and of the Book Series Structures and Infrastructures. Dr Frangopol is the recipient of several medals, awards, and prizes, from ASCE, IABSE, IASSAR, and other professional organizations, such as the OPAL Award, the Newmark Medal, the Alfredo Ang Award, the T.Y. Lin Medal, the F. R. Khan Medal, and the Croes Medal (twice), to name a few. He holds 4 honorary doctorates and 12 honorary professorships from major universities. He is a foreign member of the Academy of Europe and the Royal Academy of Belgium Honorary Member of the Romanian Academy of Technical Sciences, and Distinguished Member of ASCE.

Konrad Bergmeister

Konrad BERGMEISTER. O. Univ. Prof. Dipl.-Ing. MSc. PhD Dr phil. Dr techn. Bergmeister graduated at the Technical College of Mechanical Engineering in Bolzano. From 1979 to 1985 he completed a degree in civil engineering at the University of Innsbruck. From 1980 onwards, he studied at the same institution as well as folklore, art history, architectural and architectural design and philosophy, before he graduated in 1985 with a folkloric dissertation on traditional architecture in the Lower Puster Valley. In 1988, he received his second doctoral thesis with an engineering dissertation on fastening technology. From 1988 to 1990, Bergmeister performed research at the universities of Leuven, Texas and Stuttgart. In 1990 he founded the Ingenieurteam Bergmeister GmbH. In 1992, he obtained a Master of Science in Manufacturing Systems from Clarkson University. In 1993, he was appointed full professor for constructive civil engineering at the University of Natural Resources and Life Sciences in Vienna Austria. In 2003, Bergmeister received the regular membership of the Berlin-Brandenburg Academy of Sciences, and in 2004 that of the German Academy of Natural Scientists Leopoldina. Since 2006, he has been the CEO of the BBT SE, which is driving ahead the construction of the Brenner base tunnel. He has authored/co-authored more than 5 books, over 120 articles in archival journals, and many papers in conference proceedings. In 2013, he received an honorary title from the University of the German Armed Forces in Munich. In 2015, he was appointed honorary sponsor of the University of Innsbruck for his contributions to the establishment of the Euregio universities. Since May 2016 he has been President of the Foundation Südtiroler Sparkasse.