Diving services were provided to support the installation of a new Mississippi River Bridge, as well as the demolition and removal of the old bridge structure. The project included performing diving operations in swift moving currents during cold weather/water conditions with limited visibility.
Scope of Work
Ballard supplied diving services during the installation and demolition phase of the project. Ballard’s work was performed intermittently over thirteen months, requiring the ability to mobilize and demobilize rapidly to meet the client’s project needs. The project included multiple scopes of work including underwater inspection for existing site conditions, heavy lifting and rigging for alignment and placement of nine cofferdam/concrete form cells for new bridge pier installation, underwater sealing of cofferdams around driven steel casing piles with grout tubes, underwater hydraulic tooling used for disassembly and removal of cofferdams, diver assisted dredging for old pier demolition, underwater burning and demolition methods for casing and pile removal and post construction underwater surveys.
To meet the challenges of the differing and constantly changing site and weather conditions, Ballard performed diving operations during cold weather utilizing hot water dive systems to protect divers from exposure to the cold-water condition allowing for safer diving operations and higher productivity of the divers with extended bottom times. During early spring and late fall operations, when river levels and currents were increased from spring thaw run-off and heavy rains, Ballard utilized additional control methods for diver entry and exit to limit travel distance to the work zone along with secured travel lines to guide and assist dives to and from the work platform and work zones.
“The new Savanna-Sabula bridge greatly improves safety, better connects the communities, and strengthens commerce in an important part of the state,” said Illinois Transportation Secretary Randy Blankenhorn during the 2017 bridge opening ceremony.
Client: Illinois DOT
Location: Savanna, IL
Diver Depth: 37ft