Rotary-Driven Pipe Piles as a Solution in a Congested Dense Urban Construction Site-Video

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Keith Herman of Langan Engineering and Lisa Papandrea of Skanska presented a foundation solution for a congested Upper East Side Manhattan site. The new eight- to nine-story building was planned over loose, compressible marsh deposits, with dense soils and bedrock far below grade, and was surrounded by existing shallow-founded buildings.<br /><br />The original design called for 190–250 long, large-diameter drilled piles. The team instead proposed 320 rotary-driven steel pipe piles, designed to carry load through skin friction. The method combined rapid installation and minimal spoil with low noise and vibration—important benefits for the urban setting. New York City approved the alternative after a variance request and successful load testing.<br /><br />Instrumented compression tests met code settlement criteria at 155 and 170 tons. Retorque measurements were variable, so the team developed a repeatable quality-control program and retorqued 10% of production piles. The presenters concluded that the alternative suited the site, while noting that measured side-shear values were below design assumptions and settlement differences should be considered.

Keywords

foundation solution

rotary-driven steel pipe piles

Upper East Side Manhattan

skin friction

load testing

quality control program