OVERVIEW:
It may not have been as old or iconic as that other leaning tower over in Italy, but the 118-year-old co-op building that once stood at 74 Grand Street in the SOHO Historic Cast Iron District was protected by the Landmarks Preservation Commission (LPC) because it featured one of the very first cast-iron facades which gave the district its name. In 2004 some hasty and ill-considered excavations to the lot next door resulted in the building beginning to slowly tip over. So much in fact, that the 118-year-old co-op was referred to in its final days as The Leaning Tower of SOHO. The building continued to lean, and while efforts were made to save it, it had to be demolished in 2010. Before demolition the LPC required the cast iron facade be carefully removed and stored in order for it to be used on the building that would eventually rise in its place.
CHALLENGE:
As with any project in the city, mobilization and demobilization costs are always higher. Limited space to use equipment and stage product is always a bit of a logistical nightmare as well, and with an area 25’ wide and 100’ deep, this project was no exception. In addition, the neighbors took it upon themselves to (brilliantly) stake out the property line with luxury vehicles. Effective yet frustrating if you’re the equipment operator.
All installation and product staging had to take place in an area 25′ wide and 100′ deep.
SOLUTION:
Fast forward to today and 74 Grand is set to quickly rise again – this time on a solid foundation, thanks to Stelcor Drilled-In Displacement Micropiles (DDM). With minimal installation equipment required, Stelcor offers huge advantages in these situations. In nine days, Rich Anastasio and his team at EMC installed 51 Stelcor Drilled-In Displacement Micropiles to 65’ in a limited access area, using minimal equipment, and with no mess, vibration, or spoils.
Only time will tell what sort of destructive shenanigans the neighbors might get up to in the future. As for 74 Grand, she’s gonna be all right.
CLICK TO VIEW and download the print version of the case study and geotechnical report.
INSTALLER:
Rich Anastasio of EMC Inc. www.emcnj.com
GEOTECHNICAL ENGINEER:
Geo Tech Consultants, LLC
LOADS:
360 kips ultimate compression
100 kips ultimate tension
PILE DETAIL:
STELCOR 1600
18” tip or drive plate
16” corrugated grout column
13” solid grout column
8” reverse auger
5.5” O.D. X 0.361″ W.T. – 80 ksi central shaft
SOILS:
The boring logs indicate a general profile of 10’ of miscellaneous fill, followed by 10’-12’ of marshland sediments of sand, silt/clay and peat, and then 60’-75’ of glacial deposit of sand and gravel, cobble and boulder. View the geotechnical report here.
EMBEDMENT DEPTH:
Piles were installed to 65′.