Improvements in construction equipment and techniques in recent years have
made possible the use of drilled shaft foundations in diameters and lengths not
previously considered practical or feasible. Many highway bridge and other
structures are now routinely founded on drilled shafts which are 8 to 12 feet in
diameter and extending over 200 feet in depth below grade. There are unique
challenges associated with constructing such large and deep cast-in-place
foundations and engineers should be aware of the special needs associated with
site investigation, construction specifications, material requirements, and quality
assurance. This paper outlines a number of special considerations for these
foundations, along with strategies that may be employed to improve the reliability
and quality of large drilled shaft foundations.
Author: Dan Brown, Dept. of Civil Engineering, Auburn University
Publisher: DFI