The
test piles for this job were completed in early July, but production piles
did not actually start until the last week in September. These long
start up delays seem to be very common now. All the pipe was on the
job by the end of October and about 70% of the piles have been driven.
The
driving went well according to Superintendent Yan Wong. This casing
pile is very tough and not easily damaged.
The jobsite is very tight and unloading and storing the pipe created some problems. A crane was brought in for the day to do the unloading and stacking of the pipe. The crane was positioned in the street and the pipe was unloaded directly into the excavation. This generally went well except for a few trucks whose drivers could not seem to find New York City, or had engine trouble or got sick or were abducted by little green men; or was that women?
DFP S-1800 splice rings ready for
use.
The
piles were about 80' long on average. The Contractor chose to use
the DFP S-1800 splice ring to join pile sections. There are other
similar products on the market, but load transfer must be considered.
Some products have a ledge or pipe stop that is only 3/8" wide and does
not allow the full section of the pile to transfer load to the lower section
of pile. In this case the wall thickness of the pipe is .545, the
ledge on the 9 5/8" DFP S-1800 is .625. This allows for full load
transfer to the lower section of the pile. Additionally the DFP S-1800
splice ring is made with a low alloy steel with a 60 ksi yield strength.
Through
independent laboratory tests this pipe is determined to be a minimum of
90 ksi yield. Under the B.O.C.A. code you could use 35% of 90 ksi
or 31.5 ksi on the steel alone. Since the steel area of this 9 5/8"
X .545 wall pipe is 15.54 in. square the steel could carry a working load
of 490 kips or 245 tons. The piles were load tested to 320 tons for
96 hours.
Copyright 1997 Pileline Publishing
