15 AUGUST 2005
Purpose. The criteria presented in this UFC are to be used by the
engineer to develop the types, lengths, diameters or horizontal dimensions, materials
and installation methods of deep foundations. Deep foundations are those that receive
some or all of their support from soil strata at a depth where the Depth of bearing/Base
width of footing ratio is greater than 5. The materials for deep foundations may be
concrete, steel, timber, aggregates, soils and combinations of these materials including
mixed in placed soils with Portland cement, limes and fly ashes. There are many
installation methods, and some examples are driving with hammers or rams, screw type
installations, drilled installations, deep mixing, deep compaction and grout injection.
There are new developments in this field everyday. It is important to seek the latest
guidance from the references and from the geotechnical engineering community. ASCE
Geotechnical Institute and the Deep Foundations Institute are the main sources of
information for developments in deep foundations.
Scope. Apply criteria to all projects for the military services. The methods
of determining the most economical deep foundation, settlement potential, bearing
capacity and size of the deep foundations is presented in detail.
Related Criteria. Reference Chapter 10, "Foundations in Expansive
Soils" and Chapter 11, "Foundations in Areas of Significant Frost Penetration" when
designing deep foundations when either of these factors, expansive soil or significant
frost penetration, are present for a particular site.
References. These present load factor and safety factor type designs
and should be used as a unit.
Engineering Manual for Shallow Foundations, Driven Piles, Drilled
Engineering Manual for Settlement Studies
Shear Strength Correlation for Geotechnical Engineering
Design of Pile Foundations, Technical Engineering and Design
UFC 3-220-10N, Soil Mechanics