Practical Advice for Foundation Design - Micropiles for Structural Support.pdf

文档介绍：GSP 131 Contemporary Issues in Foundation Engineering
Practical Advice for Foundation Design – Micropiles for Structural Support
. Bruce1, Member; . Cadden2, Member; and . Sabatini3
1Geosystems, ., . Box 237, ia, PA 15367; PH [phone]; FAX
[phone]; email: dabruce@
2Schnabel Engineering, 510 E. Gay Street, West Chester, PA 19380; PH (610) 696-
6066; FAX [phone]; email: ******@schabel-.
3GeoSyntec Consultants, 55 W. Wacker Drive, Suite 1100, Chicago, IL 60601; PH
[phone]; FAX [phone]; email: psabatini@
Abstract
Certain details of micropile design remain unresolved between various practitioners
and such disagreements have limited the acceptability of micropiles in certain
quarters. Detailed micropile design is an extremely lengthy and plex
subject, especially when micropile groups are concerned or seismic issues must be
addressed. The paper provides a simplified step-by-step design approach discussing
initial evaluation of feasibility, review of data, binations and general
considerations. Thereafter the final design steps are discussed. These include
geotechnical strength limit states, other structural considerations, service limit states,
corrosion protection, and some seismic considerations.
Introduction
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.
F