Subsurface Exploration for I-40 Reconstruction in the Pigeon River Gorge Post Hurricane Helene-Video

Video Transcription

Video Summary

The presentation reviewed subsurface exploration for rebuilding five miles of I-40 in North Carolina’s Pigeon River Gorge after Hurricane Helene caused severe flooding and roadway failures. Repeated landslides and past repairs had shown the need for a solution resilient to another major storm.<br /><br />Teams collected more than 600 geotechnical data points using soil-nail records, air-track probes, conventional borings and rock coring, geophysics (MASW), and televiewer imaging. Bedrock depth varied widely, and difficult boulder-rich overburden made drilling challenging. A centralized geospatial database, Mortar, brought logs, imagery, laboratory results, and progress data together for shared, timely access.<br /><br />Design concepts included roller-compacted concrete buttresses, walls, concrete-rock-fill toe treatments, and interlocking pipe piles where bedrock was deep. Tunnels and viaducts were considered but rejected as impractical or costly. Key lessons were to organize data centrally, combine rapid exploration methods with conventional drilling, and use timely field information to adapt designs to variable ground conditions.

Keywords

subsurface exploration

I-40 reconstruction

Pigeon River Gorge

geotechnical data

storm resilience

geospatial database