The project included more than 11 miles of tunnelling that encompasses work in multiple locations in Manhattan, Queens and the Bronx. It provides travel to over 162,000 passengers per day. Since most of the project was in urban areas, delivering the construction materials was challenging due to severe space constraints and the job scope. For the smooth flow of construction, a temporary retaining wall was suggested.

Strata’s geotechnical experts suggested an innovative approach to this – StrataWall™. This solution incorporated a hot-dip galvanized 4×4 wire form facing elements with geotextile and geogrid facing wrap. The StrataWall™ system and design met project requirements and provided the needed 10-year design life. It was constructed to fill a 70-foot (~21 m) hole that abutted vertical walls on either side. Materials had to be delivered with a crane into the hole where the MSE wall was constructed. Since StrataGrid™ is rolled and easy to handle, it made material transport and delivery much more efficient.

Strata’s innovative solution resulted in an economical, fast, and smooth construction of the mechanically stabilized earth wall.