Located in the heart of New York City's Chinatown stands a construction site that will become 9-story mixed-use structure housing a below-ground parking garage facility, several apartment units, and retail storefronts.

Unfortunately, while the majority of New York City is built on the famous Manhattan Schist formation (a very solid geological formation), Chinatown rests on beach-like sand. These deposits cause challenges for contractors as they construct foundations for structures such as this 9-story building. In this case, the surrounding structures began to suffer extreme settlement as the initial underpinning activities were in process.

Structural Preservation Systems' (SPS) Geostructural Division was contracted to stop the settlement and implemented Sodium Silicate grouting to stabilize the sandy soils beneath the surrounding structures. This grouting operation is an efficient solution when the right chemical compounds (Sodium Silicate, Diacetin), pipe angles, and volumes are used. The objective is to turn the loose, flowable soil into a dense material that is hard to the touch (compressive strengths of about 300PSI), but not as hard as cement.

For this project, the unique soil stabilization method was composed of the strict placement of four separate sleeve port pipe (SSP) patterns, which were driven to lengths between 12 and 23 feet deep. Grout volumes ranged between 15 and 29 gallons between 15-inch port increment.

Final quantities were in excess of 5,833 lineal feet driven and 61,409 gallons of sodium silicate installed.