Miami Brightline - Engineered support for high-speed rail service

Florida's southeast coast features roughly 75 miles of urban landscape commonly referred to as the Miami metroplitan area, reaching from West Palm Beach in the north to Miami at the southern end. Notably, reliable intercity public transportation had been largely absent for this metropolis of over six million people.

All Aboard Railroad hoped to solve that issue with its Brightline Express Train Service and a goal to connect passengers from Miami all the way north to West Palm Beach and beyond. The Miami portion of the $3+ billion project began in early 2015 as part of the first phase of construction on the entire railway system. The service between Miami and West Palm Beach launched in 2017 and expanded service from Miami to Orlando began in September 2023, transporting passengers up and down the Atlantic coast at speeds between 80 and 125 miles per hour.

Suffolk Construction was the general contractor for the Miami portion of the project working alongside Baker Concrete who was responsible for the concrete base of the railway system.

The Challenge

When designing a railway structure, or any structure, a number of load requirements must be met or exceeded for safety and long-term performance reasons. The shear loading transfer requirement for the deck slab superstructure at the Miami Station was in excess of 30 kips.

A proven, cost effective and maintenance-free solution was needed to carry this significant loading for the design life of the rail system while allowing for permanent movement at the joint.

The Solution

For the Florida Brightline project, the MB Double Shear Dowel was chosen due to its unique ability to transmit high shear loads in concrete from the elevated rail superstructure to the pier foundations below. Project requirements for the railway design system necessitated that shear and moment loadings be transferred while limiting the deflection of the track over the project life-cycle.

Leviat’s engineering team, alongside Ericksson Technologies Inc. in Tampa, FL, accomplished this by demonstrating the shear capacity of the Double Shear Dowel system in laboratory testing that exceeded 10-million load cycles and by providing the client a PE sealed design conforming to ACI 318-11 specifications for this high profile application.

Manufactured from duplex stainless steel to ensure a high degree of corrosion resistance with no requirement for additional protection, the two-part assembly provided All Aboard Florida and their engineering and construction teams with a simple, maintenance- free solution to control the longitudinal movement in the rail viaduct superstructure’s concrete construction joints while transferring significant shear loading.

The Result

Additional material and product testing for the Double Shear dowel was provided to AECOM and the Brightline Florida team to confirm that the performance requirements of the project were met. For this project, over 130 Lockable Dowels were successfully installed, creating cost savings, construction time reduction and most importantly, a safe structure for the railway system.

Additional fatigue testing for the Double Shear Dowels was required by AECOM and the All Aboard Florida team in order to demonstrate that the dowel’s would meet the expected loading requirements for the lifetime of railway superstructure. To demonstrate the superior performance of the Double Shear Dowels laboratory testing was developed that subjected the dowel to a maximum 60 kip shear force for over 10-million load cycles. Peak deflections were measured and the Double Shear Dowel easily exceeded the acceptance criteria.