How to Save 1.12M Dollars and Not Have to Bulldoze a Building in Chicago

by | Jan 17, 2018 | Stelcor Case Study

STELCOR DDM piles for 5 story building in Chicago

OVERVIEW:
In Chicago, a 60-foot tall movie theater was sold to a Banner Real Estate Group, who are converting it into a climate-controlled storage facility.  This project will add five floors to the building, as well as an addition for elevators, increasing the floor area to 97,349 square feet.  The weight of the added floors rendered the existing foundation insufficient.

Stelcor DDM for 5 story building in chicago

CHALLENGE:
The piles needed to reinforce the existing foundation had to be installed in close proximity to the existing walls, as well as inside of the building. Other piling methods were considered but were either cost-prohibitive or could not be installed in low-headroom areas. The only remaining option would have been to demolish and rebuild the structure on a new foundation.

stelcor installed for 5 story building in chicago

SOLUTION:
J-2 Concrete, Inc. presented our STELCOR® Drilled-In Displacement Micropiles as an alternative. Foundation piles were installed and tested to 103 kips. With minimal installation equipment and a window of 30 days, the crew at J-2 installed 257 STELCOR DDM piles over the site. There is no vibration with STELCOR DDM, so piles were installed against the 55’ high masonry walls without causing any damage to the structure.

stelcor installed for 5 story building in chicago

The full case study with boring logs and load test data are available upon request.

INSTALLER:
J2 Concrete

GEOTECHNICAL ENGINEER:
NASHnal Soil Testing, LLC

STRUCTURAL ENGINEER:
Highland Engineering

ARCHITECT:
Reitan Architects LLC

LOADS:
191 kips ultimate compression
92.2 kips ultimate compression

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 + EMBEDMENT DEPTH:
The boring logs indicate a general profile of very soft clay.
Piles were installed to 45’ and 70’.