NYC – 75 STELCOR Piles for 8-Story Cantilevered Condos

by | Jul 30, 2021 | Case Study, Micropiles, Stelcor Case Study, Stelcor®

 

OVERVIEW:
After a decade of waiting, this 8-story building is finally going vertical. This striking cantilivered ground-up structure is located in the heart of NYC’s East Village neighborhood.  Designed by HTO-Architect for Colonnade Group, the building will rise 8 stories and will stand out with its contemporary and glassy structure.

Condominium Cantilever Support With STELCOR® Micropiles

CHALLENGE:
The lot was only 24’ wide and 100’ deep with existing structures on either side. This created both design and installation challenges. Spoils removals for this site were going to be cost prohibitive. As with any project in NYC, available space for equipment and product staging and were virtually nonexistent. The original design specifieid (52) 9 5/8” drilled piles to be installed to 50 feet.

IDEAL Manufacturing Team at Condominium Build SiteSOLUTION:
Drilled-In Displacement Micropiles were submitted as an alternate.  The pile depth was reduced by 20′ and costly spoils were elimininated.  In 5 days, and with minimal installation equipment, (75) STELCOR piles were installed to a depth of 30’.  Due to decreased installation depths and faster installation times, STELCOR saved time and money.

75 First Avenue Building Concept Made Possible With STELCOR® Micropiles

Image Credit: HTO Architect

LOADS:
100 kips ultimate compression
10 kips ultimate lateral

PILE DETAIL:
STELCOR 1400
16” tip or drive plate
164” corrugated grout column
11” solid grout column
8” reverse auger
5.50” O.D. X 0.361” W.T. – 80 ksi
central shaft

SOILS + EMBEDMENT DEPTH:
A thin layer of fill over 35-55 feet of sand, 40-70 feet of varved silt, sand, and clay, 30 feet of glacial till, and 85 feet of decomposed rock, all underlain by marble bedrock. Water table 10’ below excavation. 30’embedment depth.

INSTALLER:
CMI Structural Solutions

ARCHITECT:
HTO Architect

DEVELOPER:
Colonnade Group

GEOTECHNICAL ENGINEER:
Mueser Rutledge Consulting Engineers