Prasenjit Basu
Doctoral Student, Purdue University, Civil Engineering Building, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051, USA
Monica Prezzi
Assistant Professor, Purdue University, Civil Engineering Building, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051, USA. Tel.: +1 765 494 5034; fax: +1 765 496 1364. E-mail addresses: mprezzi@ecn.purdue.edu (Corresponding author)
Deep foundations are extensively used in geotechnical engineering practice. The wide spectrum of piling methods results in a variety of pile types. Each type behaves differently, depending on the installation or construction methods. On one end of the spectrum are non-displacement piles, the classical examples of which are bored piles or drilled shafts. These piles are constructed by removing a cylinder of soil from the ground and replacing it with concrete and reinforcement. On the other end are full-displacement piles, such as closed-ended pipe piles or precast reinforced concrete piles, which are typically driven into the ground. Driven piles preload the materials below the toe of the pile and displace the soil surrounding the pile shaft laterally during the installation process. Therefore, displacement piles are, in general, more likely to have a stiffer response than non-displacement piles. This is true particularly in the case of sandy soils where displacement causes densification.
A large number of pile types can be referred to as auger piles if the similarities in the installation methods are considered. A continuous- or partialflight auger or a helical tool is drilled into the ground to install these piles. A variety of auger pile equipment is available in the market; each is associated with a certain degree of soil displacement during installation. For example, under auger cast-in-place (ACIP), we have augercast piles, which are called continuous-flight-auger (CFA) piles in Europe.
Auger piles, namely auger cast-in-place piles and drilled displacement piles, are used extensively in practice. The advantages of these piles are that their construction is fast, economic and environmentally friendly. These piles, depending on the method of installation, can be classified as partial- or full-displacement piles. Hence, their capacities are greater than that of drilled shafts with comparable length and diameter and, in many cases, approach that of driven piles. The installation methods and the quality control techniques for different types of auger piles were described, and the available design methods based on in-situ test results were presented. Analytical or numerical modeling of the installation of these piles combined with well-designed experiments and systematic monitoring of their installation in construction projects is needed for meaningful advances in analysis and design of these piles.
Read more: Monica Prezzi
Doctoral Student, Purdue University, Civil Engineering Building, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051, USA
Monica Prezzi
Assistant Professor, Purdue University, Civil Engineering Building, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051, USA. Tel.: +1 765 494 5034; fax: +1 765 496 1364. E-mail addresses: mprezzi@ecn.purdue.edu (Corresponding author)
Deep foundations are extensively used in geotechnical engineering practice. The wide spectrum of piling methods results in a variety of pile types. Each type behaves differently, depending on the installation or construction methods. On one end of the spectrum are non-displacement piles, the classical examples of which are bored piles or drilled shafts. These piles are constructed by removing a cylinder of soil from the ground and replacing it with concrete and reinforcement. On the other end are full-displacement piles, such as closed-ended pipe piles or precast reinforced concrete piles, which are typically driven into the ground. Driven piles preload the materials below the toe of the pile and displace the soil surrounding the pile shaft laterally during the installation process. Therefore, displacement piles are, in general, more likely to have a stiffer response than non-displacement piles. This is true particularly in the case of sandy soils where displacement causes densification.
A large number of pile types can be referred to as auger piles if the similarities in the installation methods are considered. A continuous- or partialflight auger or a helical tool is drilled into the ground to install these piles. A variety of auger pile equipment is available in the market; each is associated with a certain degree of soil displacement during installation. For example, under auger cast-in-place (ACIP), we have augercast piles, which are called continuous-flight-auger (CFA) piles in Europe.
Auger piles, namely auger cast-in-place piles and drilled displacement piles, are used extensively in practice. The advantages of these piles are that their construction is fast, economic and environmentally friendly. These piles, depending on the method of installation, can be classified as partial- or full-displacement piles. Hence, their capacities are greater than that of drilled shafts with comparable length and diameter and, in many cases, approach that of driven piles. The installation methods and the quality control techniques for different types of auger piles were described, and the available design methods based on in-situ test results were presented. Analytical or numerical modeling of the installation of these piles combined with well-designed experiments and systematic monitoring of their installation in construction projects is needed for meaningful advances in analysis and design of these piles.
Read more: Monica Prezzi
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