Analysis of Age-dependent resilience for a highway network with aging bridges

Open Access
Author:
Kezhiyur, Alben Jose
Graduate Program:
Civil Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
April 01, 2015
Committee Members:
  • Dr Swagata Banerjee Basu, Thesis Advisor
Keywords:
  • Resilience
  • Network functionality
  • Memphis transportation network
  • fragility
  • recovery patterns
Abstract:
Bridges are key links connecting different critical facilities in a highway transportation network. Bridge damage in the event of an extreme hazard may cause severe traffic disruption and thus directly affect the functionality of a highway network. The extent of damage that a particular bridge may experience under a certain extreme event condition depends on various factors including severity of the extreme event (e.g., earthquake magnitude), proximity of the bridge with reference to the event location (e.g., the distance from the epicenter of an earthquake), structural health (e.g., chloride induced deterioration, aging), to name a few. Based on the extent of damage that bridges in a highway network may undergo, efforts are made to restore the original functionality of a network in a fast and economically efficient way. The concept of network resilience is thus closely tied to promptness in restoring the original functionality of a network after an extreme event occurs. Although the quantification of resilience for highway network greatly depends on the post-event recovery model, network resilience inherently depends on the pre-event structural condition of constituent bridges. The present study considers a small highway network (with 35 bridges) in the Memphis region. Structural deterioration of constituent bridges due to chlorine diffusion over the bridge life span is studied. The highway network is studied primarily at two different time scenarios, year 2010 and year 2050 for an earthquake of magnitude 6. For each corresponding year, ages of the bridges are identified based on their year of construction and accordingly bridge fragility curves are developed at various stages of bridge life based on past research. Thus developed fragility curves are used in conjunction with recovery patterns to explore time-dependent change of network resilience considering total travel time in the network as the functionality measure. Also, the percentage number of links having different velocity to capacity ratios for each time scenarios is calculated to understand the congestion in different links. It is observed that aging due to chloride deterioration has an adverse impact on seismic resilience of bridge network.