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Geotechnical News • September 2013
www.geotechnicalnews.com
GEO-INSTITUTE NEWS
For conference information:
www.
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ing on-line instructions at:
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How to become a Geo-Institute
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get your section and/or branch message
out to prospective and existing mem-
bers? Then become a Geo-Institute
Chapter. ASCE encourages this effort.
There are no fees or chapter dues
required by the G-I. There is just one
short Memorandum of Understand-
ing (MOU) that is needed. You can
increase your membership recruitment
efforts and event marketing by convert-
ing your ASCE Geotechnical Group to
a G-I Chapter or by forming a new G-I
Chapter. Download the MOU from the
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. Discover
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Industry News
Bertha is star of Seattle
Highway’s Tunnel Project
Seattle’s $2 billion Highway 99 tunnel
project is underway using the giant
tunnel-boring machine, known as Ber-
tha. It is the world’s largest-diameter
tunnel-boring machine.
Crews began assembling the 326 ft-
long tunneling machine at the south
end of the pit shortly after it arrived
in April from Osaka, Japan. Once the
57.5-ft-diameter drilling machine was
completed, tunnel boring was sched-
uled to begin as this issue went to
press. A 10-ft-long interactive model
of Bertha is displayed at Milepost 31,
the project’s information center in
Pioneer Square.
1,450 pre-cast concrete rings will
be fabricated for lining the tunnel in
Frederickson, near Tacoma. The rings
will be installed by the boring machine
just behind the cutting head, forming a
tunnel structure as the machine makes
it way under Seattle.
New Bay Bridge.
Safer than the old?
If the 1989 Loma Prieta earthquake
with a magnitude of 7.1 were to hap-
pen again, the new eastern span of
the Bay Bridge in California would
be substantially safer than the 1936
cantilevered truss span motorists cur-
rently use, according to new analysis
recently presented to Bay Area legisla-
tors. It was stated that 80 years ago,
engineers didn’t understand or fully
respect vibrations generated by an
earthquake, but the design of the new
bridge incorporates a greater under-
standing of vibration theory.
Engineers designed the 1936 bridge
to withstand maximum ground
accelerations of 10 percent of 1 G, a
measurement of the force of gravity
on a moving object, within a 5-second
period. Compare that with the new
bridge, which has been designed to
survive equivalent Gs of up to 180
percent.
The three agencies overseeing
construction of the $6.4 billion Bay
Bridge presented the new seismic
comparison data to the Bay Area
Caucus. Along with Senate Trans-
portation Committee Chairman Mark
DeSaulnier, the Bay Area lawmakers
requested the briefing in the wake of
mounting public concerns about the
span’s seismic safety.
Much of the worry stems from the
failure of 32 high-strength steel bolts
embedded in seismic stabilizers that
snapped in early March, forcing
Caltrans and the contractor, American
Bridge/Fluor Joint Venture, to scram-
ble to repair the damage and reassure
the public that the other steel compo-
nents are sound.
The bridge opening could be post-
poned if Caltrans, the Bay Area Toll
Authority, and the California Trans-
portation Commission cannot com-
plete the bolt retrofit, or if ongoing
tests reveal problems with other steel
fasteners on the span.
National Cooperative Highway
Research Program
The National Cooperative Highway
Research Program (NCHRP) conducts
research in problem areas that affect
highway planning, design, construc-
tion, operation, and maintenance
nationwide.
Each year, the American Association
of State Highway and Transporta-
tion Officials (AASHTO) refers a
research program to the Transportation
Research Board consisting of high-
priority problems for which solutions
are urgently required by the states.
The AASHTO program for FY 2014 is
expected to include 15 continuations,
50 new projects, and 2 projects con-
tingent on additional funds becoming
available
The NCHRP announced its FY 2014
NCHRP Project for Potential Contrac-
tors program at
www.trb.org/Main/
Blurbs/168954.aspx
To be notified
of new NCHRP requests for propos-
als, send an email to
listserv@lsw.
nas.edu
with SUBSCRIBE NCHRP_
ANNOUNCE in the body of the
email. To stop the emails, substitute
UNSUBSCRIBE for SUBSCRIBE.
For information:
Economic impact of hydraulic
fracturing for gas & oil
The Manhattan Institute for Policy
Research recently published the paper
“The Economic Effects of Hydro-
fracturing on Local Economies. A
Comparison of New York and Penn-
sylvania” by Diana Furtchgott-Roth
New eastern span of California’s
Bay Bridge. (Credit: Karl Mondon/
Bay Area News Group)