· First
yellow floating turbidity barriers are put in place in the water to
retain any suspended sediment (water flows through barriers, more
dense sediment remains) with silt fence on the land, for the same
purpose.
· Barge(s)
are brought in with the crane and pile-driver.
· In some
cases, sheet piles (sheets of steel) are temporarily installed to
prevent erosion of the bank.
· Test
piles are driven to determine the length of the piles. Pile driving
analysis done by engineers during the driving determines length of
the permanent piles.
· Permanent
piles are driven once a determination of required length is made.
Piles are cast at a concrete plant, barged in and then driven into
ground. Approximately 2 to 4 piles are driven per day.
· The
footings are formed and poured at the casting yard (precast) then
barged to the Causeway and placed on top of the piles.
· The
piers are also precast, barged to the site and erected on top of
the footing.
· The
precast beams are cast at the concrete plant and barged in and set
in place on top of the piers.
· The
deck is formed and poured in place on top of the beams.
· Cosmetics
and drainage work is then completed.
· Voila!
You have a bridge!
Interesting Facts
Span information
· Bridge
A has 19 spans @ 144’ and 2 spans @ 130'
· Bridge
B has 13 spans @ 144’
· Bridge
C has 26 spans @ 144’ and 1 span @ 120’
Height of bridges
· Bridge
A clearance at center span: 70’ at Mean High Water.
· Bridge
B height: Varies slightly in accord to geometry of the
bridge.
· Bridge
C height: Varies in accord to geometry of the bridge. Has a
navigable channel of 26'.
Footings
· For
Bridge A all water footings except one are composed of twenty-one
(21) 30" pre-cast concrete piles.
· For
Bridges B & C the water footings are composed of fifteen (15)
30" pre-cast concrete piles.
Footing configuration
· Bridge
A basic footing configuration: 49’-6"’ X 19’6" X
6’
· Bridge
B basic footing configuration: 36’ X 21’ X
6’.
Pre-cast weight of footing: 303 tons.
Average weight of pre-cast piers: 190,000 Lbs.
· Bridge
C Basic footing configuration: 36’ X 21’ X
6’.
Pre-cast weight of footing: 303 tons.
Ship impact bridges will be able to sustain: 1 kip = 1000
Lbs.
· Bridge
A will be able to sustain a maximum ship impact force of 1200 kips
(1.2 million Lbs). The balance of ship impact that the remainder of
the footings will be able to sustain is 800 kips (800,000 Lbs) on
average.
· Bridges
B & C will be able to sustain a maximum ship impact force of
200 kips (200,000 Lbs
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