Transcript TITLE
Reconstruction of the Eads
Bridge Highway Deck
Michael J. Cronin, PE, SE
Eads Bridge History
Opened to traffic July 4, 1874
Designed and planned by James Buchanan Eads
Underwater salvage expert
Shipbuilder
No formal education
Hired by the St. Louis and Illinois Bridge Company
as engineer-in-chief for this project
Eads Bridge History
Design and construction innovations
deep pressurized caisson construction
Eads Bridge History
Design and construction innovations
deep pressurized caisson construction
high strength cast steel
Eads Bridge History
Design and construction innovations
deep pressurized caisson construction
high strength cast steel
design of components to permit ease of
replacement
Eads Bridge History
Design and construction innovations
deep pressurized caisson construction
high strength cast steel
design of components to permit ease of
replacement
cantilever construction of main arch spans
Eads Bridge History
Design and construction innovations
Deep pressurized caisson construction
high strength cast steel
design of components to permit ease of
replacement
cantilever construction of main arch spans
500 ft spans were 200 ft longer than any built
previously
Bridge Ownership History
Illinois and St Louis Bridge Company
Missouri Pacific Railroad Company
Terminal Railroad Association
City of St. Louis / Bi-State Development Agency
Rehabilitation Challenges
Preserve historically important aesthetic elements
Use existing substructure to support new highway
deck
Maintain light rail traffic during construction
New Cross Section
Four 11 ft lanes designed for HS-20 loading
1 ft offset between outside lanes and the Jersey
barriers
5 ft sidewalk on south side of roadway
Bridge Sections
West Approach
West Arcade
Main Spans
East Arcade
East Approach
West Approach & East Arcade
Substructure:
3 longitudinal walls
Outside walls of stone or brick masonry, original
construction
Center wall of minimally reinforce concrete,
constructed in the 1920’s
Substructure repairs
Tuckpointing
Crack repair
Reinforced concrete pads
West Approach & East Arcade
Longitudinal concrete beams over First and
Second Streets
Spalled and cracked
Some section loss in reinforcing
Capacity found to be marginally acceptable
Repairs
fiber composite wrap
total replacement
West Approach & East Arcade
Existing superstructure:
transverse concrete
floorbeams with distinctive sloped ends
Replaced with prestressed concrete I girders with
special ends
designed as 2 span continuous to maintain
distribution to supporting walls
Precast SIP form panels utilized
West Arcade
Substructure: 2 longitudinal walls
East portion - stone masonry arches in fairly good
condition
concrete infill used to strengthen arches
West portion - reinforced concrete open arches in
poor condition
total replacement with new reinforced concrete
arches
West Arcade
Existing superstructure
non-composite rolled beams at 4 ft spacing
deck replaced in early 1980’s
design called for cleaning & painting beams,
scarifying & overlaying deck
Change order proposed by contractor
total replacement of superstructure with composite
rolled beams at 8.5 ft spacing
Main Spans
Existing substructure - 2 piers and 2 abutments
founded on bedrock
Good condition
Top surfaces of piers and abutments required
crack repair and resurfacing
Main Spans
Arch truss superstructure
no retrofit required if dead load from new floor
system and deck is held < 116 psf
Main Span Floor System
Existing floor system: half-filled grid deck on
floorbeams at 6 ft spacing
New floor system eliminated floorbeams between
columns - 12 ft spacing
Exodermic™ Deck specified to span the 12 ft
between floorbeams
74 psf using standard weight aggregate
Main Span Floor System
The Exodermic™ deck, or an “unfilled steel grid
deck composite with a ±4.5” reinforced concrete
slab” provides:
Light weight
Structural efficiency
Protection of Light Rail operating below
ExodermicTM Bridge Deck
Special Main Span Features
Overlook areas at piers and abutments
Bridge can be closed to traffic for special
weekend events
Electrical outlets built into north barrier
East Approach
10 spans of new steel superstructure on new
concrete substructure - 1000 ft
Highway deck starts above MetroLink track and
end below
Highway deck had to be built around MetroLink
bridge and elevated station as well as abandoned
foundations
East Approach
Drilled shaft construction
one shaft per pier
up to 7 ft in diameter
utilized to minimize footprint and to avoid vibrating
adjacent MetroLink foundation
East Approach
Steel straddle bents
transverse beams
support the highway deck over the MetroLink
tracks and elevated station platform where
traditional supports cannot be used
Connection to MetroLink
Handicap accessible ramp built to connect
sidewalk to East Riverfront Station
Reopening - July 4, 2003
THANK YOU