Improving the Resilience and Sustainability of Buried Infrastructure

Much of the existing infrastructure is approaching or has already exceeded its intended service life. As infrastructure continues to age, problems worsen, and the risk of failure increases. In addition, due to global changes in weather and climate, it is anticipated that overall temperatures will rise in Canada and worldwide. Therefore, it is essential to determine the extent to which climate change will affect the performance of buried structures and design accordingly. Hence, the proposed research is interdisciplinary and focuses on various fields of resilient infrastructure, including the effects of climate change, to develop sustainable infrastructure solutions using recycled waste materials. The proposed research program includes six tasks that deal with various analysis and design issues. The first task constitutes a comprehensive assessment of the potential adverse impact of new piled foundations on existing tunnels, considering actual soil conditions and the current condition of the tunnel lining. Based on the research results, a realistic exclusion zone will be established and/or precautionary measures will be developed to allow close-by piled foundations. In addition, a comprehensive study in the second, third and fourth tasks quantifying and optimizing rehabilitation methods for steel culverts will be performed. The study will consider the climate change effects on the degradation progress of culverts with medium to large spans. Based on the results of this study, Canadian municipalities can better manage their aged culverts. The use of lightweight compressible materials can reduce the stresses on buried structures. Hence, in the fifth task, an innovative application of tire-derived aggregate (TDA) to improve the performance of buried culverts will be investigated. The last research task will explore a new application of TDA behind the abutments of integral abutment bridges (IABs). Under cyclic thermal loading, the structure contracts in cooler temperatures and expands in warmer temperatures, inducing active and passive earth pressures within the soil backfill and resulting in stresses in the structure foundation piles. Climate prediction models forecast that overall temperatures will rise in Canada and worldwide. Therefore, it is necessary to determine the extent to which climate change will affect the performance of IABs and design accordingly. As a lightweight material, TDA can reduce the pressures on the abutments and result in an economical design. In addition, the larger elastic range of TDA can enhance the long-term performance of IABs by reducing the amount of ratcheting. The proposed methodologies will help assess the hazards associated with buried infrastructure with the aim of reducing the potential for catastrophic failures in major transportation arteries, which translates into increased safety for Canadians and reduced cost for development in urban areas.