Proj Overview

Project Overview

The Miami Intermodal Center ( MIC) facility connects local and regional transportation networks to Miami International Airport, including Tri-Rail, Amtrak, buses, and taxis. For train-riding comfort, the project criteria required the vertical frequency of vibration of the composite section to be greater than 2.5 Hz. Choosing a high-performance precast concrete U-beam design enabled the team to meet the requirement for rigidity while still providing the service and strength limit states for the maximum span considered.

The use of precast concrete was an economical choice for both the short and the long term. The bridge was constructed at an estimated half the cost of a similar precast segmented bridge, and was up to 20% less expensive than a similar steel structure. The U-beam precast system provided a low maintenance cost, is simple to inspect, and it allowed for a very pleasant aesthetic solution.

Precast Solution

The project consists of 72 in. (1830 mm) modified Florida precast concrete U beams for the typical spans, segmental precast concrete boxes for the long-span units of the guide-way structures, and a few spans of 24 in. (610 mm) cast-in-place concrete slab at the connection to the Earlington Heights Station.

Along the 2.5 mi (4 km) alignment, which consists of tangent, spiral, and circular curves, the precast concrete U-beam portion of the guide-way features 43 spans of single track section, 33 spans of double track section, and 5 spans of multiple track section. The total number of U beams is 129, with a typical length of 120 ft (37 m) and a maximum length of 133 ft (41 m). Each beam was then delivered via truck using a 19-axle dual-lane rig that easily transported the 129 short ton (117 tonne) beam the approximately 250 mi (400 km) from Tampa to Miami.

 

Awards
2013 Design AwardsBest Transportation Special Solution
Project Team

Engineer of Record

URS Corp., Miami, FL 

Owner

Miami Dade Transit 

Precaster

Standard Concrete Products 

Contractor

Odebrecht/OHL 

Photo Credit

URS Corporation

Key Project Attributes

  • Precast concrete U-beam design enabled the team to meet the requirement for rigidity while still providing the service and strength limit states
  • U-beam precast system allowed for low maintenance cost and is simple to inspect
  • The use of precast concrete was an economical choice for both the short and the long term

Project/Precast Scope

  • Project Cost: $180 million
  • Bridge Length: Single Track: 5350 ft (1630 m); Double Tracks: 3856 ft (1175 m); multiple tracks: 598 ft (182 m)
  • 72 in. (1830 mm) modified Florida precast concrete U beams