Proj Overview

Project Overview

Rehabilitating the Route 76 Bridge, one of the oldest open-spandrel-arch designs in the country, required a number of precast concrete elements to retain the original appearance and minimize disruptions to traffic along this heavily traveled route. The 1087 ft (331 m) long bridge consists of five 195 ft (59 m) arch spans over the lake with concrete deck-girder approach spans. It carries about 20,000 vehicles daily and provides a vital connection between Branson, MO, and Hollister, MO.

Precast Solution

The rehabilitation features precast concrete spandrel beams and partial-depth deck panels. The beams were placed on the existing spandrel columns and connected to existing spandrel-column steel using a grouted connection. Then specially designed partial-depth precast, prestressed concrete deck panels were placed to span the 10 ft (3 m) distance between the spandrel columns.

The panels also were used as stay-in-place formwork for the cast-in-place portion of the slab. The two 52 ft (16 m) long approach spans were replaced with precast concrete I-girders and partial-depth deck panels.

The spandrel beams had pockets cast into them to allow the existing column steel to be reused in the connection detail. The beams were set on epoxy, which acted both as a leveling pad and joint sealant around the exterior of the reinforced connections. This approach saved months in the construction schedule. Casting time was saved by using only three form types to cast 95 beams.

In addition, the bridge was constructed with a flared entry on one end to add a storage lane for a new roundabout intersection. This involved creating variable-girder spacing and complicated geometry, but standard precast concrete I-girders were used along with the standard partial-depth precast concrete deck panels.

 

Awards_
2012 PCI Design AwardsTransportation Award: Best Rehabilitated Bridge
Project Team

Engineer

Horner & Shifrin Inc., St. Louis, MO 

General Contractor

Jensen Construction Co., Des Moines, IA 

Owner

Missouri Department of Transportation, Springfield, MO 

Precaster

Coreslab Structures Inc., Marshall, MO

Key Project Attributes

  • Precast allowed the construction schedule to move along quickly
  • Precast concrete provided the most cost-effective way to rehabilitate the 1930s arch bridge

Project/Precast Scope

  • Bridge length: 1087 ft (331 m)
  • Project cost: $4.45 million
  • Standard precast concrete I-girders were used along with the standard partial-depth precast concrete deck panels.