Ground Improvement for Building Support

Harrisburg Area Community College – Public Safety Center
Law Enforcement Center Building

Harrisburg, PA

Mitigation of Historic Fill

Client/Owner:  Harrisburg Area Community College

ARM Group provided design and construction phase geotechnical services for the 50, 000 square foot Law Enforcement Center building, part of the Public Safety Center expansion on HACC’s north campus.  Significant portions of the north campus are built over historic fill of varying character and depth, and fill materials ranging from inert construction debris to incinerator ash to municipal refuse have been encountered.  The LEC building was located over an uncontrolled, unregulated dump believed to have operated for several decades prior to its abandonment in the late 1950’s.  Design phase investigations revealed a subsurface profile consisting of 10 to 15 feet of relatively clean fill underlain by 10 to 15 feet of unconsolidated and highly variable historic fill, overlying soft river sediments and unconsolidated alluvium.  ARM evaluated foundation options to maintain post-construction building settlements to within acceptable limits, and recommended pre-loading of the building footprint in conjunction with compaction grouting beneath load-bearing walls and columns.  During construction ARM provided on-site inspection and oversight of the preloading program and compaction grouting.

ARM’s services for this project included:

  • Performing exploratory borings and preparing foundation recommendations
  • Performing an Environmental Site Assessment
  • Preparation of preloading and compaction grouting specifications
  • Evaluation of settlement monitoring data taken during the preload period
  • Oversight of compaction grouting program and tracking of pay quantities
  • Inspection and testing of earthwork and footing subgrades

    Compaction Grouting Beneath Building Foundation