OVERVIEW:
The 100-year-old Rand Hall at Cornell University is undergoing significant changes.   The top two floors of the building are set to become the home of the new Mui Ho Fine Arts Library.  The new called for the column loads to be increased but it was also imperative that the structure of the building be preserved.

Stelcor Drilled-In Displacement Micropiles at Cornell University

CHALLENGE:
Access to the interior of the building would have been more of a challenge were it not for a hole which was left in the side of the building in 2015 after “A young driver failed to navigate the curve.” Once inside, however, low headroom and close column spacing were two of the biggest challenges encountered by anybody working on the site.

Stelcor Drilled-In Displacement Micropiles at Cornell University

SOLUTION:
With value-added engineering and STELCOR® DDM, CMI (cmistructural.com) presented an alternate foundation solution.  As previously mentioned, the installation team was restricted by low headroom and close column spacing.  It’s in situations like this where STELCOR® really shines.   To allow for more space to operate equipment in the building, the high-shear grout mixer was set up outside.  Freezing temperatures are not an issue with the type of grout used with STELCOR®.  All piles were installed to approximately 30’ below the finished floor and embedded into the dense glacial till.  A bare shaft helical pile was used as a pilot drill to loosen the dense soil so the STELCOR® piles could be installed more easily.  STELCOR® saved time and money, met the unique challenges and requirements presented, and caused no damage to the foundation of the historic building.

 

INSTALLER:
CMI Structural Solutions www.cmistructural.com

LOADS:
45 kips compression allowable
45 kips tension allowable
10 kips lateral

PILE DETAIL:
STELCOR® 1200
14” tip or drive plate
12” corrugated grout column
9” solid grout column
8” reverse auger
5.5” O.D. X 0.361″ W.T. – 80 ksi central shaft

SOILS + EMBEDMENT DEPTH:
Dense soil layer at 5’. Piles installed to 30’ below the finished floor and embedded into the dense glacial till.