Arkansas River Bridge Scour Repair - Nebraska LTAP River Bridge Scour Repair September 13, 2017...

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