U.S. Department of Transportation
Federal Highway Administration
|Subject:||INFORMATION: Micropile - Design and Construction Guidelines Manual||Date:||August 14, 2000|
|From:||/s/ Original signed by:
Acting Director of Bridge Technology
|In Reply Refer to:||HIBT-20|
|To:||Directors of Field Services
Federal Lands Highway Division Engineers
Distributed with this memorandum is publication number FHWA-SA-97-070 entitled "Micropile - Design and Construction Guidelines." A micropile is a small diameter (typically less than 300 mm), drilled and grouted pile that is typically reinforced. Worldwide use of micropiles has grown since their original development in the 1950s, and in particular since the mid-1980s. Micropiles are principally used as elements for foundation support to resist static and dynamic loading conditions, and less frequently as in-situ reinforcements for slope and excavation stability. The advantages of micropiles are that their installation procedure causes minimal vibration and noise, they can be installed in difficult ground conditions, and they can be used in areas with low headroom and restrictive access. The implementation of micropile technology on United States transportation projects has been hindered by the lack of practical design and construction guidelines. This reference manual is intended as a "practitioner-oriented" document containing detailed guidance on micropile design, specifications, construction monitoring, cost data, and contracting methods. Special acknowledgment is extended to the Western and Central Federal Lands Office and the Western Resource Center for their technical and administrative efforts in development of this manual.
Technical assistance on the design and construction of micropiles, including a 1 day seminar, will be added to the scope of services available under Demonstration Project 116 - Ground Improvement Methods. Questions regarding the manual content or technical assistance regarding micropiles can be directed to Mr. Jerry DiMaggio at 202 366-1569 or Mr. Al Kilian at (360) 696-7748.
With this memorandum, we are distributing two copies of this publication for each Resource Center, five copies for each Division Office (including three copies to be forwarded to the State DOTs by the Division Office) and three copies for each Federal Lands Office. This report is available to the public from the National Technical Information Service in Springfield, Virginia. In addition, this publication will be posted on the FHWA Geotechnical Information Center at the Office of Bridge Technology website at http://www.fhwa.dot.gov/bridge/ under the geotechnical page.