Reconstructing the caisson inside the cofferdam.
The Missouri Department of Transportation made significant progress
in constructing Pier 3 of the Bill Emerson Memorial Bridge last month.
A 12-hour concrete pour took place on Oct. 3. The pour is the first step in sinking
the steel caisson, which will act as the foundation for Pier 3, into the Mississippi
River. The 67-foot by 109-foot cutting edge of the caisson was recently transported
in sections to the middle of the river where it was assembled and reinforcing
steel was added before it began its journey 50 feet below the river bed. Four
pours are needed to completely sink the caisson. They are taking place at roughly
two week intervals.
Suppliers Delta Concrete, Inc. and McDonald Co., Inc. hauled the concrete from
their respective plants in Cape Girardeau to the Illinois side of the river.
The concrete was transported from the Illinois side because of safety and to
avoid interfering with barges in the navigation channel. A temporary bridge was
constructed so the concrete trucks could transport the concrete to barges. The
barges then carried the concrete to the cofferdam and was placed inside the caisson
by cranes.
The caisson resembles a rectangular honeycomb larger than the size of a river
barge. The walls were filled with the concrete and the sand areas of the river
bed located between the different chambers of the caisson's grate will be removed
in the coming weeks with heavy excavating equipment. The removal of the sand
is what will actually cause the weight of the caisson to sink the cutting edge
below the surface. The caisson will cut through the sand to the rock in the river
bed located beneath what will be one of the structure's two main support towers.
"This was a day of much anticipation for our workers and our contractor, Traylor
Brothers, because it signified a very significant, positive step since joining
forces earlier in the year," said MoDOT District Engineer Scott Meyer. "This
milestone not only begins to lay the foundation for Pier 3, but provides a foundation
for our great partnership with Traylor Brothers to grow and become even stronger."
Back to Bill
Emerson Memorial Bridge Projects |
