GSP 131 Contemporary Issues in Foundation Engineering
Practical Advice for Foundation Design – Micropiles for Structural Support
D.A. Bruce1, Member; A.W. Cadden2, Member; and P.J. Sabatini3
1Geosystems, L.P., P.O. Box 237, Venetia, PA 15367; PH (724) 942-0570; FAX (724) 942-1911; email: email@example.com Schnabel Engineering, 510 E. Gay Street, West Chester, PA 19380; PH (610) 696- 6066; FAX (610) 696-7771; email: firstname.lastname@example.org. GeoSyntec Consultants, 55 W. Wacker Drive, Suite 1100, Chicago, IL 60601; PH (312) 658 0500; FAX (312) 658 0576; email: email@example.com 2 3
Certain details of micropile design remain unresolved between various practitioners and such disagreements have limited the acceptability of micropiles in certain
Detailed micropile design is an extremely lengthy and
initial evaluation of feasibility,
review of data, loading combinations and
geotechnical strength limit states, other structural
considerations, service limit states,
corrosion protection, and some seismic considerations.
Through the efforts of many authors it is now well established that micropiles have been used throughout the world since their development in Italy in 1952 (FHWA, 1997). In North America, the use is somewhat more recent, and as is typical with a relatively new specialty geoconstruction technique, most of the technical knowledge has resided with the contractors. Not surprisingly therefore, and even given that such contractors have displayed admirable skill, knowledge, and zeal in their developments, there still tends to be more certainty and consensus within the industry with respect to issues relating to construction and testing than to design.
Following the FHWA State of Practice review in 1997, there have been major efforts made in the quest for a “unified” design approach. Such efforts include the FHWA Implementation Manual (2000), the efforts of the Micropile committees of both the