Optimal bridge retrofit strategy to enhance disaster resilience of highway transportation systems.

Details

• Creators:
  Banerjee, Swagata ; Chandrasekaran, Sandhya ; Venkittaraman, Ashok
• Corporate Creators:
  Thomas D. Larson Pennsylvania Transportation Institute
• Corporate Contributors:
  United States. Dept. of Transportation. Research and Innovative Technology Administration
• Subject/TRT Terms:
  • Highway bridges
  • Retrofitting
  • Earthquake resistant design
  • Scour
  • Resilience
  • Seismicity
  • Benefit cost analysis
  • Jacketing (Strengthening)
  • Statistical analysis
  • Optimization
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• Publication/ Report Number:
  PSU-2012-01 ; LTI 2014-11
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  Mid-Atlantic Universities Transportation Center
• Abstract:
  This study evaluated the resilience of highway bridges under the multihazard scenario of earthquake in the presence of ; flood-induced scour. To mitigate losses incurred from bridge damage during extreme events, bridge retrofit strategies are ; selected such that the retrofit not only enhances bridge performance, but also improves resilience of the system consisting ; of these bridges. The first part of the report focuses on the enhancement of seismic resilience of bridges through retrofit. To ; obtain results specific to a bridge, a reinforced concrete bridge in the Los Angeles region was analyzed. This bridge was ; severely damaged during the Northridge earthquake due to shear failure of one bridge pier. A seismic vulnerability model of ; the bridge was developed through finite element analysis under a suite of time histories that represent regional seismic ; hazard. The obtained bridge vulnerability model was combined with appropriate loss and recovery models to calculate the ; seismic resilience of the bridge. The impact of retrofit on seismic resilience was observed by applying a suitable retrofit ; strategy to the bridge, assuming its undamaged condition prior to the Northridge event. A difference in resilience observed ; before and after bridge retrofit signified the effectiveness of seismic retrofit. The applied retrofit technique was also found to ; be cost effective through a cost-benefit analysis. A first-order, second-moment reliability analysis was performed and a ; tornado diagram developed to identify major uncertain input parameters to which seismic resilience is most sensitive. ; Statistical analysis of resilience obtained through random sampling of major uncertain input parameters revealed that the ; uncertain nature of seismic resilience can be characterized with a normal distribution, the standard deviation of which ; represents the uncertainty in seismic resilience. An optimal (with respect to cost and resilience) bridge retrofit strategy under ; multihazard was obtained in the second phase of this study. A multi-objective evolutionary algorithm, namely Non-dominated ; Sorting Genetic Algorithm II, was used. Application of this algorithm was demonstrated by retrofitting a bridge with column ; jackets and evaluating bridge resilience under the multihazard effect of earthquake and flood-induced scour. Three different ; retrofit materials—steel, carbon fiber, and glass fiber composites—were used. Required jacket thickness and cost of ; jacketing for each material differed to achieve the same level of resilience. Results from the optimization, called Pareto-optimal set, include solutions that are distinct from each other in terms of associated cost, contribution to resilience ; enhancement, and values of design parameters. This optimal set offers the best search results based on selected materials ; and design configurations for jackets.
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• Format:
  PDF
• Funding:
  DTRT12-G-UTC03
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27476/dot_27476_DS1.pdf
• File Type:
  [PDF - 768.12 KB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha256:3d09794268823bb9daf60477bf45498839c226080a1da9e44e186c15167782ea