Mammoet sets bridge spans in Texas
17 August 2020Mammoet’s crew successfully set four precast box-girder bridge units into place as part of the construction of the ‘Signature Bridge’ in Irving, Texas, USA.
Once complete, the bridge will stretch 152m (500ft) long over State Highway 114 and will connect the former Texas Stadium site to a planned mixed-use development, which is set to include a new Dallas Area Rapid Transit light rail station.
Each bridge unit weighed approximately 720t and was transported and set utilising Self-Propelled Modular Transporters (SPMTs), during very specific, planned overnight traffic outages to ensure minimal disruption to the public.
The original plan was to use jacking and skidding equipment so the bridge could be built on top of the existing bridge and skidded over to its new foundation. However, Mammoet devised a solution for the units to be built directly on the ground in an off-site location, after which each unit would be picked up and self-loaded using SPMTs. This method is known as the Accelerated Bridge Construction or ABC method.
The ABC method avoided the need for work to be done at height, eliminating many safety concerns, and allowing for quicker loading time than originally anticipated, ultimately eliminating the need for two overnight shifts of previously planned work.
In order to execute as planned, a trench was dug underneath each 37m long section to allow for installation of a beam under each end of the bridge unit. The sections were then lifted using a 635t (700USt) capacity gantry system and once elevated, Mammoet's crew drove SPMTs underneath to load each piece before carefully delivering to the abutments.
