Each pile location was predrilled through the landfill approximately
70 feet and cleared of debris and leachate prior to installing the
36-inch CMP casing. This made pile location accuracy very difficult
due to the top 70 feet of the pile having no skin friction with the soil.
Because the top of the piles in the CMP casing were unsupported and
had lateral movement, FCI constructed and utilized templates at each
predrilled hole to help preserve accurate location of the piles.
Pile splices were required to be located a minimum of 35 feet below
the bottom of landfill elevation to mitigate corrosion. This was not possible
because the bottom section of the splice pile would have needed to
be a shorter length than the 70-foot predrilled hole, which eliminated
the possibility of splicing the bottom and top pile sections together. FCI
recommended and was approved the method of epoxy coating the splice
prior to driving to provide a barrier from the surrounding landfill. To
minimize splicing, FCI cast full length 18-inch PCPS pile up to 145
feet. Full length pile that were fabricated 123 feet or longer were lofted
with a four-point pick using two cranes.
Because the project site was located on a landfill, obstructions were
a common underground obstacle. Underground obstructions would be
pushed from one pile location to the adjacent location while predrilling,
which would damage the already installed CMP casing. FCI brought
in a vibratory hammer and mandrel with a conical tip to clear out the
obstructions and allow the pile to be driven to the required tip elevation.
Project management
Innovative project management provided cost savings and maintained
the strict schedule:
•• To provide a cost savings to the project, FCI and Lusardi fabricated
and installed only two to three piles in each pile cap at the
beginning of production to allow Haley & Aldrich time to determine
if the remaining piles could have revised shortened lengths.
•• Because there were many obstructions encountered during predrilling,
FCI utilized a vibratory hammer with a mandrel and
conical tip to clear out the CMP casing and clear the drilled hole
to allow the pile to advance down to tip while driving. This method
avoided the necessity to excavate down to clear the obstruction,
which would have delayed schedule and been more expensive.
Environmental impact mitigation
•• All cut-off material was salvaged and recycled for LEED credits.
•• CMP casing was permanently installed through the landfill layer
prior to pile installation to mitigate the contaminated waste material
from being pushed into the ground water below.
•• The CMP casing was backfilled with gravel after pile installation.
This prevents down drag on the pile during landfill settlement or
liquefaction during seismic activity.
•• Because the project was located on a landfill, all personnel working
on the project site had to complete the HAZWOPER 40
training.
•• All personnel had to be asbestos and methane trained.
•• Used mobile drip pans under equipment to insure compliance
with project SWWWP requirements
FCI is proud to be a team member on this project with Lusardi
Construction, Haley & Aldrich and Steelwave LLC. t
Foundation Constructors, Inc. won a 2017 PDCA Project of the Year
Award in the Land: Greater than $5 Million category.
LAND: GREATER THAN $5 MILLION
Predrill through
landfill using a
Bauer BG46
Moving production pile
Installing production pile
94 | ISSUE 4 2017