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Client Name
City of Des Moines
Client Type
Services Provided
  • Bridge Design
Project Manager
Contact Steven Kunz, PE
Structural Engineer

Single Bridge Replaces Two Obsolete Bridges

This 897-foot long, 40-foot wide pretensioned prestressed concrete (PPC) beam bridge with a five-foot sidewalk replaces two structurally deficient and functionally obsolete bridges—a 247-foot long by 28-feet wide PPC beam bridge over I-35/80 and a 455-foot long by 28-feet wide PPC beam bridge Beaver Creek. Project construction began in spring 2016 and was completed in fall 2016.

Shuck-Britson and Snyder & Associates teamed to provide the following services for the Iowa Department of Transportation (DOT):

  • Development of the project concept statement
  • Preliminary bridge and roadway plans
  • Hydraulic analysis and documentation
  • Final bridge and roadway design plans
  • Rapid responses to issues that arose during construction, including pile driving inquiries and erosion/ revetment modifications

Unique Features & Design Challenges

  • Multiple pier types were utilized as appropriate at roadway and waterway crossing locations
  • Aesthetic details such as special blisters to support light poles, steel pipe handrail and exterior fencing with steel mesh panels were incorporated to enhance the bridge’s appearance
  • A non-standard deck cross section with raised pedestrian sidewalk prevent ponding on the sidewalk to support pedestrian safety
  • Prototypical details were developed for this unique condition of a raised sidewalk and exterior fence interacting with the deck expansion joint and stub abutment
  • The additional sidewalk load resulted in non-uniform beam reactions, requiring careful analysis to determine bearing pad sizes
  • Stub abutments with a bridge deck expansion device were required due to bridge length
  • Due to excessive bridge movement at the south abutment, modified sliding bronze plate bearings were required
  • The pier located in the median of I-35/80 was designed for vehicular collision

The project was let by the Iowa DOT, and all plan submittal dates were met.