JIM NELSON, IOWA DOT MASSENA LATERAL BRIDGE SLIDE CASE STUDY

J I M N E L S O N , I O WA D O T

MASSENA LATERAL BRIDGE SLIDE CASE STUDY

PROJECT LOCATION

• IA 92 over Small Natural Stream, 1.0 mile west of Jct. IA 148

PROJECT LOCATION

EXISTING STRUCTURE

• 40’ x 30’ Steel I-beam• Constructed 1930• Reconstructed

1949• Overlay 1968• Retrofit rail 1992• Overlay 1998

EXISTING STRUCTURE

• Structurally deficient – sufficiency rating is 38.2• Bridge is not

adequate for legal loads – posted “One truck at a time.”

PROPOSED REPLACEMENT BRIDGE

• Pretensioned Prestressed Concrete Beam Bridge

MOBILITY IMPACTS

• Detour traffic for duration of construction• 7 miles out of distance travel for detour• AADT (2012) – 1,460 w/ 16% trucks• User costs for 180 day detour• Indirect $437,000• Direct $15,000 (Co. Road Maint. & Detour

Signing)

PROJECT STAGING AREA

UTAH DOT WANSHIP BRIDGE SLIDE

BRIDGE CONSTRUCTION VISUALIZATION

SEMI-INTEGRAL ABUTMENT

• Abutment Diaphragm Details – sheet number 14

SLIDING PAD

• Superstructure Details – sheet number 15• Bonded PTFE surface on bearing pad detail

PROJECT COST

• Let April 16, 2013

• Winning bid $1.3 Million

• Bridge unit cost - $112/SF

• Historic bridge unit cost - $85/SF

CRITICAL CLOSURE SCHEDULE

Activity 1 2 3 4 5 6 7 8 9Bridge Removal and GradingPavement RemovalRevetmentPile DrivingAbutment FootingBridge slidePrecast wingsBarrier RailingGranular BackfillApproach pavingLongitudinal GroovingSteel GuardrailPavement Marking

Day

MASSENA LATERAL BRIDGE SLIDE WEB SITE

CONSTRUCTION PROGRESS

ACKNOWLEDGEMENTS

• Designer – Iowa DOT• Constructability Review – Michael Baker

Corporation• ABC Peer Exchange – Utah DOT• ABC Detail Testing – Iowa State University• Construction Administration – Iowa DOT• Prime Contractor – Herberger Construction Co., Inc.• Precast Wing Supplier – Cretex Concrete Products• Precast Beam Supplier – Cretex Concrete Products• HfL Grant – FHWA