Geotechnical survey to determine geology of riverbed at East End Bridge location
Louisville, KY – (October 10, 2005) -- Soil and bedrock are as important to bridge
design as the steel and concrete that give each bridge its own unique identity.
On Oct. 10, engineers will begin to evaluate how the geology at the bottom of the
Ohio River will affect foundation alternatives for the East End Bridge design plans.
Engineers from the firm of Fuller, Mossbarger, Scott and May Engineers, Inc., will
lead the geotechnical investigations along a section of the river that has never
been surveyed. Over a one- to two-week period, crews will use a drill apparatus,
operated from a barge, to take samples from the river bottom at each of the bridge’s
four proposed pier locations. At each drill site, soil will be sampled at intervals
of approximately five feet until the drill hits bedrock. Then, rock coring techniques
will be used to bore a minimum of 20 feet below the rock surface to recover a continuous
sample of bedrock.
Recovered soil and bedrock will be studied and tested for strength and other physical
characteristics. The results will be used to develop a general subsurface profile
of the materials at each pier location. It is estimated that 45 soil samples and
approximately 80 feet of rock core will be recovered.
“These geotechnical investigations will help us determine what we’re dealing with
at the bottom of the river in terms of foundation material,” said Dan Carrier, engineer
with Parsons, Brinckerhoff, Quade and Douglas, and section design manager for the
East End Bridge. “Design engineers working on the new Downtown Bridge can refer
to existing information because geotechnical surveying was done for the adjacent
Kennedy Bridge in 1960. Our surveying will be particularly important because we
don’t have access to that kind of information – it simply doesn’t exist for our
location.”
The East End Bridge will be supported by a shoreline pier on each side of the river,
and by two piers in the river located 550 feet from the shore on each side. The
two inside piers will be 1,100 feet apart. When completed, the East End Bridge will
have three lanes of northbound and three lanes of southbound traffic, plus a 17-foot
pedestrian walkway/bike path.
Work crews will set up the barge and drilling equipment on Oct. 10. Excavations
are set to begin that week.
The current geotechnical work on the East End Bridge is necessary to gain subsurface
information to understand potential design considerations. Similar work is not necessary
in the area of the new Downtown Bridge, as that structure is proposed adjacent to
the existing Kennedy Bridge. Geotechnical information gathered for the Kennedy Bridge
is available to facilitate the initial design of the new bridge. Full geotechnical
investigation will have to occur on the new Downtown and East End Bridges later
when more detailed design information is known.
The Ohio River Bridges Project addresses the long-term, cross-river transportation
needs in the Louisville-Southern Indiana region. The Federal Highway Administration,
Indiana Department of Transportation and Kentucky Transportation Cabinet agreed
that the only feasible way to meet cross-river transportation needs would be to
construct two new bridges and rebuild the Kennedy Interchange (Spaghetti Junction)
in downtown Louisville and approaches in Indiana. Of a variety of options studied,
the “Two Bridge” alternative, which includes a new bridge next to the existing I-65
Kennedy Bridge, the reconstruction of the Kennedy Interchange and a new East End
Bridge, meet transportation needs with the least amount of impact on environmental
resources and communities.
The new Downtown Bridge, which is also part of the Ohio River Bridges Project, will
be just east, or upstream, from the Kennedy Bridge. Plans for both bridges, which
are scheduled for completion in 2020, are in the early design phase. For more information,
residents or businesses can visit the project web site, at
www.kyinbridges.com.
For more information, residents or businesses can visit the LSIORBP Web site, at
www.kyinbridges.com.