Model 4500S
Standard Piezometer
SCAN ME
SAME DAY GEOKON maintains a stock
Producing Quality Geotechnical
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www.geokon.biz/PileDriver
| Lebanon, NH, USA
+1.603.448.1562 | info@geokon.com
of many commonly used
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LAND: LESS THAN $500,000
in the river. Due to cost and environmental
requirements, a minimum foundation
footprint was of benefit below the river
Ordinary High Water (OHW) and within
the wetted perimeter.
Challenges
The 90/140 temporary bridge bents needed
to be positioned such that there was a minimum
impact to the river for recreational
uses. This solution included designing pile
bents spacing to avoid the river alignment.
There were restrictions on the number of
pile that could be installed within the river
wetted perimeter and within OHW at each
site. Design for each bridge focused on
minimizing the number of piling used for
each bridge and using materials that maximized
spans.
The 90/154 site had very hard pile driving
conditions caused by the shallow rock
type geology of the Ellensburg formation.
PPM and the geotechnical engineer had to
work closely using driving date from the
pile hammer and PDA results to achieve the
required pile embedment without damaging
the piling.
Special innovation
The 90/154 temporary bridge utilized the
efficient ACROW superstructure, a selflaunching
and re-useable bridge style.
This is the longest self-launching style
bridge used in Washington State on a
public interstate.
A winning project
This project required the rapid design and
construction of two separate temporary
bridges, work trestle and four shoring
bents. The contract originally allowed three
months for design, immediately followed
by two months for in-water construction.
Design and procurement were conducted
simultaneously in order to stay on schedule.
Two separate construction crews were
provided at each site to construct both
bridges simultaneously. A local operator’s
union strike occurred during the in-water
work window, which shutdown the project
for a month. PPM worked with WSDOT
and Graham, the prime, and regulators to
obtain an expanded work window. Bridge
construction was completed in one season,
as originally planned, and allowed the
existing bridge rehabilitation work to commence
on schedule. t
Bridge construction was completed in
one season, as originally planned, and
allowed the existing bridge rehabilitation
work to commence on schedule.
56 | ISSUE 3 2020 www.piledrivers.org
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