Sustainability of structural piles: New York City case studies and US application

The building industry accounts for 37–40% of total world-wide carbon dioxide (CO₂) emissions. Due to the large amount of embodied carbon in foundation systems this has brought attention to their use of energy. Structural Piles (Drilled Shafts, Augured Cast-In Place [ACIP] piles, Driven Steel HP Piles, Fiber Reinforced Polymer [FRP], Full Displacement Piles [FDP]) are a material intensive part of a structure that can also be an underutilized area when considering the entire structural carbon footprint. This study presents a synthesis of the literature concerning the environmental sustainability of pile foundations which were reviewed based on peer-reviewed articles between 2005 and 2025. In addition to the general studies on the sustainability of pile foundations; a number of these studies focused specifically on the environmental issues associated with New York City’s (NYC) subsoils and its implications to sustainable design. A second focus was made toward broadening the scope beyond NYC and examining the broader U.S. applicability. The literature presented in this study has been synthesized using verifiable data. Some key findings include: (1) The Global Warming Potential (GWP) due to steel production varies widely depending upon the method of production. EAF production generates GWP ranging from 0.36 to 0.70 t CO₂e/ tonne for scrap metal produced via electric arc furnaces to 2.0–2.3 t CO₂e/ tonne for BF-BOF production. Using a single reference set (BF-BOF 2.0–2.3 and scrap EAF 0.7 t CO₂e/tonne), the scrap-EAF route gives an approximately 65–70% lower GWP than the BF-BOF route; (2) Substitution of OPC with 50% GGBS results in a 41% reduction in GWP for concrete, whereas substituting OPC with 30% FA results in approximately a 21% reduction in GWP; (3) Optimization of pile geometry using computer modeling can result in reductions of 45–76% in embodied carbon compared to traditional industrial designs while maintaining identical specifications and code compliance; (4) Non-displacement cast-in-place techniques (CFA, ACIP and FDP) provide numerous benefits regarding construction phase sustainability including no spoils generated, significantly less noise and vibration and lower energy requirements during installation compared to impacts driven systems; and (5) Five major land mark NYC infrastructure projects Second Avenue Subway Phase I, LaGuardia Airport Terminal B, Hudson Yards Platform, One World Trade Center and the NYCHA Hurricane Sandy Recovery Program show how different approaches to geotechnical engineering and site specific engineering applications can respond to the documented subsurface variability of NYC’s soils. Verified sustainability attributes included LEED v4 Gold and Envision Platinum certification, optimized selection of materials through load test driven evaluation and innovative use of fiber reinforced concrete linings.