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Public Roads - January/February 2006

January/February 2006
Issue No:
Vol. 69 No. 4
Publication Number:
Table of Contents

Training Update

New Course Addresses Design and Construction of Micropiles

National Highway Institute(NHI)

Micropiles, which are often used in foundations to resist static and seismic loading in highway infrastructure, are a relatively new technology for which design and construction methodologies have only recently been fully developed. Also used as in situ reinforcements for slope and excavation stability, micropile technology is particularly applicable in situations where access is difficult or overhead clearance is limited.

To offer training in this emerging technology, the Federal Highway Administration's (FHWA) National Highway Institute (NHI), the International Association of Foundation Drilling, and the International Society on Micropiles recently teamed up to develop a new course, Micropile Design and Construction (#132078A). Neither NHI nor any other associated organization has offered a similar course before.

"The purpose for developing and delivering this course and the accompanying Federal Highway Administration Micropile Design and Construction Guidelines [FHWA-NHI-05-039] is to provide 'practitioner-oriented' technical guidance," says Barry D. Siel, P.E., senior geotechnical engineer with the FHWA Resource Center.

The course targets practicing geotechnical, foundation, construction, and bridge/structural engineers who have knowledge and experience in the design and construction of driven piles and drilled shaft foundations. Further, the course builds upon the basic concepts presented in the NHI Soils and Foundations Workshop (#132012A), Drilled Shafts (#132014A), and Driven Pile Foundations--Design and Construction (#132021A) courses. Note that the Soils and Foundations Workshop is a recommended prerequisite.

Upon completion of this course, participants will be able to briefly describe the history and current status of the micropile industry; identify potential micropile applications; explain construction constraints, techniques, and performance; assess the feasibility of micropiles for a given application; prepare conceptual and basic designs and evaluate contractor-submitted designs; select appropriate specifications and contracting methods and prepare contract documents; and describe requirements for construction monitoring and inspection.

For course scheduling, contact the NHI Training Team at 703-235-0528 or For more information, visit NHI's Web site at

This figure shows a typical micropile in cross section with a hypothetical footing and subsurface profile. The micropile components are labeled, including the reinforcing bar, casing, centralizer, grout, and pile cap anchorage. Also shown are design dimensions including bond length, plunge length, and bond zone diameter.
Source: Micropile Design and Construction Guidelines, FHWANHI- 05-039.


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