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

PPT Presentation

Pdf Summary

The presentation describes Keller and Morris-Flood Associates’ soil-nailing work for a major Princeton campus construction project involving four new buildings: Environmental Studies, the Commons, Bioengineering, and Chemical and Biological Engineering. Basement construction required cuts of approximately 35–40 feet across a site with varied elevations and existing buildings and utilities.<br /><br />Soil nailing was selected as a top-down retaining method with relatively low vibration and the potential for an architectural shotcrete finish. The work included about 34,750 square feet of permanent soil-nail walls and 10,300 square feet of temporary walls, as well as temporary soldier-beam-and-lagging support. The permanent walls would ultimately be buried and not visible.<br /><br />Keller and MFA revised the bid design. Their redesign used a single shotcrete layer instead of two, covered nail-head assemblies with shotcrete for corrosion protection, eliminated PVC weep drains in rock, and specified epoxy-coated soil-nail bars and hardware.<br /><br />Construction required close coordination around existing and proposed utilities. Field teams also encountered weaker, more variable fill than expected, leading to some soil nails underperforming pullout tests and requiring higher-load testing and collaboration with the design team. Irregular rock conditions presented additional excavation challenges.<br /><br />Work began in May 2022 and was substantially complete by December 2022, with a small amount of work finished in March 2023. The project was reported as successful, with the client and construction manager satisfied with the work’s quality and the team’s performance.

Keywords

soil nailing

Princeton campus

retaining walls

shotcrete

basement excavation

temporary shoring

permanent soil-nail walls

utility coordination

pullout testing

epoxy-coated bars