Slope Support and Stabilization Using Existing, Abandoned Timber Piles-Video

Video Transcription

Video Summary

Gershon Larson of Thornton Tomasetti presented a slope-stabilization project for an LNG terminal expansion on the tidal Providence River. The site had to be raised 12–15 feet to withstand 500-year floods, but deep organic silt, peat pockets, and variable subsurface conditions created settlement and stability concerns. Investigations combined borings, cone penetrometers, and MASW surveys to characterize the soil layers.<br /><br />The site also contained buried gasworks foundations supported by decades-old timber piles. Rather than remove them, the team excavated and sampled about 25 piles, assessed their condition, and incorporated their reduced capacity into slope-stability models. Plaxis finite-element analyses and limit-equilibrium checks evaluated representative sections and pile arrangements.<br /><br />The final design combined new precast piles, geotextiles, geogrids, wire baskets, and riprap, adapting the details around existing foundations. The project showed how careful field investigation can turn legacy structures into useful components of a new stabilization system.

Keywords

slope stabilization

LNG terminal expansion

tidal Providence River

soil investigation

timber piles

Plaxis finite-element analysis