Construction Quality Assurance

Milton S. Hershey Medical Center Expansion

Inspection of Micropile Installation at Milton S. Medical Center

Hershey, PA

Inspection of Deep

Client: The Gilbane Company
Owner: Penn State University 

ARM was subcontracted by the Gilbane Company to provide construction-phase monitoring during installation of drilled-in-place pipe pile (a.k.a. micropile) foundations for two major structures associated with an 800 million dollar expansion of the Milton S. Hershey Medical Center. The structures include a cancer treatment and research facility, and a parking garage. They are supported by over 800 micropiles socketed into the sinkhole-prone limestone underlying both sites. The piles installed at the garage structure varied from 40 to over 300 feet deep. Micropile installation was complicated by intense fracturing of the bedrock, which in some areas extended more than 100 feet below the top of the limestone surface. Due to the extensive fracturing, numerous deep micropiles were installed, some extending to depths of over 250 feet. The problems, delays, and cost associated with extending the piles through the fractured rock prompted additional testing. The planned load testing program at the garage was expanded to include evaluation of pile capacities that could be derived within the highly fractured rock, resulting in the adoption of longer bond lengths within the fractured rock to reduce overall pile lengths.

Micropile installation at the garage structure was completed in 2006, and pile installation at the cancer facility was scheduled to be finished in late 2007.

ARM’s services for this project included:

  • Participation in design of the micropile load testing programs
  • Inspection and documentation all pile installations
  • Preparation of remedial recommendations for sinkholes which developed during pile installation
  • Performance of quality control testing of the grout used to fill the piles and associated bond zones

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