Micropiles in Karstic Dolomite: Similarities and Differences of Two Case Histories

Micropiles are being used today for a variety of applications. As the size and complexity of today’s superstructures increase, difficult subsurface conditions in karstic dolomite preclude the use of traditional deep foundation systems. A report is presented on the redesign of the proposed deep foundations and installation of the micropile systems for two different projects. The first project involved a highway project in the Allentown, Pennsylvania area that included a $55 million, 6-span bridge crossing over the Lehigh River, Lehigh Canal, and Norfolk-Southern RR near Easton, PA. For this project, the micropile alternate design provided an efficient design, particularly given the adverse geology and site conditions at the Route 33 bridge site. Cost savings on the caisson design were approximately $200,000 with 3 months saved on the project schedule. The second project involved the redesign of a deep foundation system for a new $58.5 million building constructed by the Pennsylvania State University in State College, PA. Nearly 9,000 linear feet of micropile was installed for the structure. The valued engineered micropile system incoporated at the University provided an approximate $150,000 cost savings to the owner. The authors conclude that the deep foundation alternative selected for the site was a success. The similarities and differences of the two projects with regard to geology, design, load transfer, and installation are also summarized.

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures;
  • Pagination: pp 674-681
  • Monograph Title: GeoSupport 2004. Drilled Shafts, Micropiling, Deep Mixing, Remedial Methods, and Specialty Foundation Systems

Subject/Index Terms

Filing Info

  • Accession Number: 01000224
  • Record Type: Publication
  • ISBN: 0784407134
  • Files: TRIS
  • Created Date: May 9 2005 10:12AM