Substructure Inspection & Rehabilitation North Grand Island Bridges

As part of a NYSTA term agreement, this assignment included the field inspection of the substructure units (piers and abutments - above water) on both North Grand Island Bridges located in the Buffalo Division, Niagara Section of the Thruway (I-190) over the Niagara River.  The bridges span between the Town of Grand Island and the City of Niagara Falls.  The field inspection was performed to determine the existing condition of the abutments and piers and to establish the rehabilitation work necessary to correct deficiencies.

Watts performed a visual and hammer sounding inspection to check for concrete delamination and spalls of the above-ground and above water portions of the substructures.  Access to the piers located in the river was achieved with the use of a barge equipped with a man-lift and moved by a tugboat, while the substructure land piers and abutments were inspected with the aid of a ladder.  Field sketches were made to document the areas of delamination, concrete spalls and concrete cracks.

Based on this hands-on inspection and the findings of a diving inspection, detailed rehabilitation plans and specifications were created as well as an associated estimate to address the deterioration of the substructure units.  Also included in this assignment was the design of three overhead sign structures mounted on the bridges and one overhead sign structure located near the toll barrier located south of the bridges.  Plans, specifications and associated estimate were also compiled for these overhead sign structures.