Phoenix Project #1802
Phoenix recently completed a challenging jet grouting project in Providence RI. Over 60 columns were installed in four critical locations, directly adjacent to a 78″ brick sewer and underneath an active utility duct bank. Column diameters of 4 to 5 feet were achieved using pumping pressures of up to 400 bar (5,800 psi).
The work required numerous pieces of specialized equipment and tooling, including a Soil Mec SM-14 rotary drill rig equipped with a Jean Lutz automated control system and data logger, a Metax jet grout pump with high pressure lines, a Scheltzke grout mixing unit and ancillary agitating tank, two bulk cement silos, jet grout drill rods, monitors, and nozzles.
A combination of vertical and battered jet grout columns were required as a result of the orientation of subsurface utilities. In addition to the presence of two sensitive utility structures, the installations were further complicated by limited headroom imposed by a nearway highway viaduct.
Once completed, the jet grouting successfully created closures of four “windows” in a perimeter steel sheeting system, providing continuity of both groundwater cutoff and temporary earth retention.