Great Island Bridge Replacement
This $8.5 million project included the replacement of the structurally deficient, load-restricted nine-span bridge. This bridge provided unique construction challenges, as it was the only point of access on and off the island for residents. The existing structure was timber which required bracing during demolition and restricted the capacity of construction vehicles over the existing structure. The small stature of this bridge led to emergency access concerns during construction. The new bridge was built in two phases, with half of the existing bridge remaining open to pedestrian and vehicular traffic with a signal to safely guide traffic on and off of the island. By maintaining one lane of traffic, the bridge was demolished and replaced one half at a time. The new three-span bridge was located on the existing bridge alignment and was approximately 200 feet in length between abutments and 48.5 feet wide. The new bridge width accommodates two 11-foot traffic lanes, two four-foot shoulders and two five-foot sidewalks.
The 4D model developed by Turino allowed the design team, stakeholders, and contractors to see how RIDOT envisioned the construction of the project. By showing true-to-scale equipment everyone was able to gain the same understanding of potential risks, like proximities to power lines, and how equipment choices can impact site and marine access. The 4D model elaborated on the pier and abutment sequences to explain in great detail the relationships between the concrete operations, pile driving, utilities and structural earthwork.
From 2D AutoCAD plans Turino created 3D models of the bridge and approaches, down to the excavations. Beyond the bridge model, we incorporated underground drainage and overhead wires. In addition, we successfully implemented state-wide GIS data into the model. MIG Construction was the successful low bidder, and construction has been underway for several months with an anticipated completion date of May 2017.