Shotcrete on Ivy: Princeton's Largest ''Ground-Up'' Undertaking-Video

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Video Summary

Keller North America presented its permanent shotcrete soil-nail wall work for Princeton University’s Environmental Studies, Bioengineering, and Chemical and Biological Engineering buildings. The project included roughly 34,600 square feet of permanent soil nailing, plus temporary walls. Soil nailing is a passive retention system that relies on small ground movements to engage the nails; it requires suitable soil stand-up time, careful excavation coordination, and stable working platforms.<br /><br />The original design called for two shotcrete layers, extensive corrosion protection, and potential rock drains. Keller and Morris Flood redesigned the system for a single, thicker reinforced facing, revised nail spacing, and epoxy-coated hardware covered with shotcrete. Favorable ground conditions and the buried wall’s lack of aesthetic requirements made these changes possible, reducing cost and installation time.<br /><br />Challenges included coordinating work around active roads and utilities, variable rock, shotcrete overages, and underperforming nails in fill. Construction ran from May to December 2022. Monitoring showed negligible wall movement before backfilling, and the project was successful.

Keywords

soil nailing

shotcrete wall

retaining wall

Princeton University

geotechnical engineering

corrosion protection