Embed Size (px)
Citation preview
Arkansas River Bridge Scour Repair
September 13, 2017
Presented by Penny L. Evans, P.E
Sedgwick County Bridge Engineer
How I got in this Scour Hole
How I got in this Scour Hole
Discovery
KS DOT Scour Evaluation Program Local FHWA Construction funds used to evaluate
local bridges for scour - statewide $5 Mil per year for 5 year program
(2011-2015) 20,000 bridges
Sedgwick County – 600 bridgesScour Evaluation – Rapid assessment Item 113 Justification forms12 POA’s In-depth Scour Analysis on 2 bridges (120 statewide)
MacArthur Road over the Arkansas River
MacArthur Road over the Arkansas River
Ultimate Scour
KDOT/TranSystems
6-foot head cut since 1975
MacArthur Road over the Arkansas River
MacArthur Road over the Arkansas River
Ultimate Scour
Ultimate Scour 19-feet* Based on
Granular streambed
1973 Plans
1973 Plans
1973 Plans
SpreadFootings
Now what
Special Inspection
Potholes – the saving grace
We need a Project
Deck Study and Geotech
GPR and CoresPEC/Kaw ValleyRichard SchlittSeth NiebaumNick SteeleWill Pyles
Deck Study and Geotech
Deck Study and Geotech
DesignSheet piling and Concrete walls
DesignSheet piling and Concrete walls
DesignSheet piling and Concrete walls
Design19-ft deep Micropile confinement
(not used – shale too stiff)
Site ConditionsPier 3 - Scour 4-ft back from
Upstream face (north)
Bridges, Inc.Stan Scudder
Site Conditions - Stabilize
Site Conditions - Stabilize
Stabilized 1/3 at a time Remaining ledge below
footing outside of column(80% unsupported)
Site Conditions - Stabilize
Site Conditions - Stabilize
Gypsum Seam
Site Conditions
Gypsum Crystals with clay seams
Gypsum – hard when confined, highly erodible when exposed
Site ConditionsPier 4 - Scour 3-ft deep on
Downstream face (south)
Completed Stabilization
SCPWDaniel SchrantRandy DownsKevin Rush
As BuiltPlan View Scour repair and
Footing dowel bars – Pier 3
As BuiltSection View Scour repair and
Concrete Encasement Wall
As BuiltElevation View Scour repair and
Concrete Encasement wall
As BuiltPlan View Scour repair and
Footing dowel bars – Pier 4
Summary
KS DOT Scour Evaluation Program $5 Mil per year for 5 year program
MacArthur Bridge Project Appreciate “Discovery” of potential scour – Thanks KS DOT! Great Contractor that was flexible as site conditions varied from
plans – Bridges, Inc. called project a “Can of Worms” Final Cost $1.66 Mil Replacement cost $7.2 Mil Pier Repair portion of contract $600,000 / Deck $1 Mil At least 25-years additional life
Arkansas River - Bridge Scour Repair
Questions ?
BREAK TIME
