Design, Construction and Long-Term Performance of a Major Highway Embankment Reconstructed using Tire Derived Aggregate (TDA)

ABSTRACT: In 2007, Tire Derived Aggregate (TDA) was used as lightweight fill to repair a very significant embankment failure of a four-lane divided highway leading to the Canada-U.S. border crossing in St. Stephen, New Brunswick. The highway embankment was under construction when it failed at a height of 12.3 m just short of the design height of 14 m. The cause of the failure was attributed to the rapid rate of construction and the intensity of the embankment loading on the low-strength foundation soils, consisting of 15 m of soft marine clay. The reconstruction strategy used TDA lightweight fill from 1.4 million scrap tires, and a system of prefabricated vertical drains installed through the marine clay over the original failure location. The reconstruction process was staged and controlled using geotechnical instrumentation and the observational approach. The reconstructed TDA embankment was successfully completed to the original design height in 2008 and continued to be monitored into 2009. From the perspective of TDA volume, this project was the largest TDA embankment in Canada and the second largest in North America at the time of construction. This TDA highway embankment has been open to the general public and in full operation since 2008. In 2020, twelve years after construction, the owner and original designers have gone back to the site to assess the long-term performance of the TDA embankment and compare against the 2008/2009 performance data and the original design assumptions. This case study reviews the design, construction and long-term performance of the TDA highway embankment from the perspectives of the owner and the designers. The long-term performance results show that the TDA highway embankment and pavement continues to perform in general accordance with the original design assumptions.