reconstruction of the eads bridge highway deck michael j. cronin, pe, se
TRANSCRIPT
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