City: Washington

State: DC

Owner: Patriot's Plaza

General Contractor: Trammell Crow

Project Description:

Jet grouting was used to construct a 56 ft deep excavation support and water cutoff wall in downtown Washington, DC.  The majority of the wall was constructed as a deep soil mixed or secant pile wall.  However, jet grouting was needed to transition from one wall type to the other and also to transition to the existing deep basement walls on the adjacent property.  Jet grouting provided a way to ensure a water-tight transition between these dissimilar materials.

The jet grout columns were installed through mixed ground consisting of sands, silts, cobbles, and marine clays.  Single fluid jet grouting created columns about 4 ft in diameter.  This diameter was more than adequate to seal between adjacent wall types.  The maximum depth of jet grout column required for this job was 50 ft.  The columns were installed in a single pass using a specialty track drill with mast extensions.

The jet grout transition seals performed well and demonstrated the effectiveness of jet grouting for water cutoff applications.