Document Type
Dissertation
Degree
Doctor of Philosophy (PhD)
Major/Program
Civil Engineering
First Advisor's Name
Armin Mehrabi
First Advisor's Committee Title
Committee chair
Second Advisor's Name
Kingsley Lau
Second Advisor's Committee Title
Committee member
Third Advisor's Name
Pezhman Mardanpour
Third Advisor's Committee Title
Committee member
Fourth Advisor's Name
Ioannis Zisis
Fourth Advisor's Committee Title
Committee member
Keywords
Post-tensioned bridges, Segmental bridges, Maintenance of bridges, Post tensioning elements, Structural model updating, Deterioration model, Reliability of post-tensioned bridges, Life cycle cost analysis, Lifetime risk analysis, Maintenance scenario selection
Date of Defense
3-29-2023
Abstract
Post-tensioned concrete bridges have become increasingly common practice in bridge industry because of efficiency, constructability, and ability to cover large spans with smaller depths. Recent reports of partial failures in post-tensioning systems however have raised the concern for safety and lifetime maintenance of post-tensioned bridges. Any recommendation should cover all parameters involved and the tradeoff between safety and cost. Risk-based decision support system for maintenance of post-tensioned concrete bridges introduced in this study aims at addressing the need by advancing the risk-based selection of inspection method, stochastic conditions assessment and reliability analysis, stochastic deterioration model, and lifetime risk analysis and maintenance scenario selection. These modules were developed for general applications and were applied to a bridge of case study to demonstrate their effectiveness in safety investigation and maintenance planning.
A novel risk-based method for selection of inspection method was developed within the decision support system that identifies the inspection method with minimum risk based on probability of inspection error, associated consequences, and corresponding inspection costs. Another major step for the new decision-support system is ability to estimate the reliability of the bridge under current condition based on the inspection results, as well as predicting the reliability index farther during the remaining service life of a bridge. This study demonstrated that the finite element modeling can be used for estimating in a stochastic manner a probability distribution for the structural strength. The demand based on the design specifications can then be compared with the estimated strength to calculate the reliability index. A simplified method for reliability analysis was proposed in this study and was successfully applied to the bridge of case study. A new deterioration model for corrosion of post-tensioning elements was then developed and compared with a series of selective small-scale experiments performed in this study. This model was also applied to the bridge of case study to estimate the reliability index at the end of its service life. Utilizing the introduced deterioration model the finite element model was predictively updated for the remaining service life of the bridge. Accordingly, lifetime risk analysis, optimization, and maintenance scenario selection was performed.
Identifier
FIDC011022
Previously Published In
"Risk-Based Selection of Inspection Method for External Post-Tensioning System of Bridges" Taeby, Mahdy, and Armin B. Mehrabi. 2022. Applied Sciences 12, no. 14: 7103. https://doi.org/10.3390/app12147103
"Decision Support Framework for Inspection and Maintenance; A Focus on Bridges using Post‐ Tensioning Tendons.” Taeby, Mahdy, and Armin B. Mehrabi. Current Trends in Civil and Structural Eng. 2019, 3, doi:CTCSE.MS.ID.000574.
Recommended Citation
Taeby, Mahdy, "Risk and Reliability-based Decision Support System for Maintenance of Post-tensioned Concrete Bridges" (2023). FIU Electronic Theses and Dissertations. 5301.
https://digitalcommons.fiu.edu/etd/5301
Included in
Civil Engineering Commons, Construction Engineering and Management Commons, Structural Engineering Commons
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