Foamed Glass Aggregate for Resilient Waterfront Construction

Many project sites located near shorelines or waterways have been faced with accommodating significantly higher flood elevations to offer resilience against extreme weather events or because of rising sea levels. The project sites are also often faced with soft compressible soil ground conditions that will lead to settlement over time or require ground improvement to mitigate this settlement. In addition, many states and municipalities have regulations in place that prohibit the reduction of onsite flood storage due to construction activities. The engineering community has been confronted with these issues in recent years, and these issues are likely to remain on the forefront of design and construction challenges in the future. One ground improvement option that is available is to raise grades with ultralightweight foamed glass aggregate (UL-FGA). UL-FGA has an in-place unit weight between 240 and 375 kN/m³ (15–23.5 pcf), has a high angle of internal friction, and is very permeable. These properties make UL-FGA well-suited for use over soft soil layers and to provide stormwater storage. In addition, UL-FGA is a sustainable choice as it is manufactured from postconsumer recycled glass and has a lower carbon footprint than other lightweight fill options. This paper also briefly describes two projects, a roadway embankment and a new residential development, in New York State that utilized foamed glass aggregate to raise elevations due to resiliency concerns.