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.
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.
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.
The full case study with boring logs and load test data are available upon request.
NASHnal Soil Testing, LLC
Reitan Architects LLC
191 kips ultimate compression
92.2 kips ultimate compression
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’.