Pile foundation is a long or slender column that is constructed from materials like reinforced concrete or steel. It is a type of deep foundation which is used to support the structure and transfer the load at desired depth either by end bearing or skin friction.
Commonly, pile foundations are designed, constructed, and tested based on the specifications and recommendations of applicable codes. ACI 543R-12, Eurocode 7, Indian Standards, and AS 2159- 2009 are examples of common and most widely used codes used to design and construct pile foundations.
Pile foundation is needed in certain conditions, for instance, when the top layers of soil are highly compressible, shallow rock level, presence of expansive and collapsible soils at the site, offshore structure, strong uplift forces on shallow foundations, and for structures near flowing water to avoid the problems due to erosion.
Various Standard Codes on Pile Foundations in Different Countries
1. ACI 543R-12
ACI 543R-12 (Guide to Design, Manufacture, and Installation of Concrete Piles) provides recommendations to assist the design architect/engineer, manufacturer, field engineer, and contractor in the design and use of most types of concrete piles for many kinds of construction projects.
It presents various types of pile foundations and discusses factors that should be considered in the design of piles and pile foundations. Moreover, the ACI 543R- 12 introduces materials used in constructing concrete piles and makes recommendations regarding how these materials affect the quality and strength of concrete.
Furthermore, minimum requirements and basic manufacturing procedures for precast piles are stated so that design requirements for quality, strength, and durability can be achieved. Finally, it outlines the general principles for proper installation of piling so that the structural integrity and ultimate purpose of the pile are achieved.
2. EN 1997 Eurocode 7: Geotechnical design
Eurocode 7 is used for all the problems of interaction of structures with the ground. It addresses not only buildings but also bridges and other civil engineering works. Eurocode 7 consists of two parts including EN 1997-1 Geotechnical design - Part 1: General rules (CEN, 2004) and EN 1997-2 Geotechnical design - Part 2: Ground investigation and testing (CEN, 2007). Eurocode 7 - Part 1 section 7 discusses the pile foundation.
In addition to EC7, Eurocodes relevant to pile foundation design are the following:
- BS EN 1990 Basis of structural design
- BS EN 1991 Action on structures
- BS EN 1992 Design of concrete structures
- BS EN 1993 Design of steel structures
- BS EN 1994 Design of composite concrete and steel structures
- BS EN 1995 Design of timber structures
- BS EN 1996 Design of masonry structures
- BS EN 1998 Design of structures for earthquake resistance
- BS EN 1999 Design of aluminium structures
3. Indian Standard Codes
Following are the Indian Standard Codes on Pile Foundations:
- IS 2911 : Part 1 : Sec 1 : 1979 Driven cast in-situ concrete piles
- IS 2911 : Part 1 : Sec 2 : 1979 Bored cast-in-situ piles
- IS 2911 : Part 1 : Sec 3 : 1979 Driven precast concrete pile
- IS 2911 : Part 1 : Sec 4 : 1984 Bored precast concrete piles
- IS 2911 : Part 2 : 1980 Timber piles
- IS 2911 : Part 3 : 1980 Under reamed piles
- IS 2911 : Part 4 : 1985 Load test on piles
- IS 5121 : 1969 Safety code for piling and other deep foundations
- IS 6426 : 1972 Specification for pile driving hammer
- IS 6427 : 1972 Glossary of Terms Relating to Pile Driving Equipment
- IS 6428 : 1972 Specification for pile frame
- IS 9716 : 1981 Guide for lateral dynamic load test on piles
- IS 14362 : 1996 Pile boring equipment - General requirements
- IS 14593 : 1998 Bored cast-in-situ piles founded on rocks – Guidelines
- IS 14893 : 2001 Non-Destructive Integrity Testing of Piles (NDT) –Guidelines
4. AS 2159- 2009
The Australian Standard (AS 2159-2009) sets out the minimum requirements for the design, construction, and testing of piled footing for building structures on land or immediate inshore locations. It has excluded offshore or deep-water construction.