Interstate 295 – I
I-295 includes the state’s first-ever load transfer platform (LTP), which required close coordination during installation. Geotechnical engineers from NCDOT worked closely with Barnhill and Sanford’s bridge crews during the first 6-8 months of the project, making bi-monthly trips to the jobsite to monitor progress. To stabilize the unsuitable material under the roadway, crews worked through a multi-phase process to construct the LTP, which included installing 500,000LF feet of wick drains, placing fill and a 5-foot surcharge to allow settlement for three months. The material where the LTP was to be located was then excavated 10 feet below the natural ground. Sanford crews then drove 30,202 feet of concrete piles with concrete caps 15 feet deep under the fill and MSE wall to support the load and prevent settlement. Crews were also tasked with installing three layers of 57 stone with alternating layers of high-strength fabric over the concrete piles. This process took 14-16 months and was performed concurrently with other construction activities on the site.