Drilled Pier modification
Drilled Pier modification
(OP)
Does anyone know or have experience in modifying existing drilled pier foundations to accomodate loading above the design loading. I have a pier (6' dia. x 17' deep) that is designed for a particular moment, and would like to know what to recommend for modifications to increase the foundation capacity. Space is limited at the location. Thanks in advance.





RE: Drilled Pier modification
RE: Drilled Pier modification
RE: Drilled Pier modification
Original geotechnical recommendations usually have to begin with limited subsurface holes, limited sampling, possibly less than desirable sample quality. These initial limitations are interpreted in a manner which assumes the slightly below average subsurface conditions and account for some problems with construction. Each 'Geotech' has a private safety/uncertainty allowance.
The actual construction may prove the wisdom of the 'Geotech's' unwillingness to 'go to the line' or may provide reason to allow a greater actual working capacity of the foundation element.
Now assuming the as-built working capacity cannot be sufficiently increased, it may be possible to improve the foundation soils with remedial techniques, such as Compaction Grouting. Additional elements, such as pin piles or helical piers or Ishvaaaq's additional surface beams or connectors may be used.
RE: Drilled Pier modification
I have used this technique for tower shafts. Have also used helical anchors with reasonable success.
Be sure you do some investigation to determine the geotechnical parameters as JAE suggests and some investigation to find the actual physical dimensions/characteristics of the shaft. There are several nondestructive techniques useful in determining these things.
RE: Drilled Pier modification
RE: Drilled Pier modification
Good Luck!
RE: Drilled Pier modification
Good luck
Mark Montgomery
deep foundations contractors inc.
Thornhill On Canada
mmontgomery@deepfoundations.net