Retaining Walls for a Sunken MLS Stadium-Video

Video Transcription

Video Summary

Rob Saunders presents the design and construction of two retaining-wall systems for a 20,000-seat stadium built with its playing field 22 feet below surrounding grade. The riverside site, within a floodplain and with groundwater near the surface, also contained cobbles and boulders.<br /><br />A perimeter secant-pile wall served as both a groundwater cutoff and permanent earth retention. Its primary piles were installed using auger-cast methods, while cased drilled shafts formed the reinforced secondary piles. The design addressed temporary cantilever conditions and permanent conditions, including support from foundation-level grade beams.<br /><br />At the stadium’s pitch-access tunnel, anchored soldier-pile walls were selected to navigate congested foundations and limit deflection. Individual pile and anchor layouts were carefully designed to avoid obstructions and one another.<br /><br />The presentation reviews geotechnical conditions, staged analyses, construction monitoring, excavation, anchoring, and final facing. Despite challenging ground, tight working space, and complex coordination, the contractor executed both systems successfully, and the stadium opened in 2021.

Keywords

retaining-wall systems

secant-pile wall

soldier-pile walls

stadium excavation

groundwater cutoff

geotechnical construction