NJTA Underwater Bridge Inspection
New Jersey Turnpike Authority Bridges over Various Waterways
W.J. Castle, P.E. & Associates, P.C. was retained in 2017 to perform the routine underwater inspections of structures between mileposts 99 to 122 along the NJ Turnpike. All inspections followed Level-2 requirements. Inspection conditions included heavy tidal flows, low in-water visibility and limited access. Inspections were coordinated around periods of low tide whenever possible. Castle provided reports detailing all findings and included repair recommendations for the bridges. Underwater cameras and measuring tools were utilized in the detailed inspection to accurately document all of the defects. Many of the bridge structures also included timber fender systems, which were included as part of the assessment and deficiency documentation.
The contract also included the specialized in-depth inspection of the western spur of the Turnpike over Sawmill Creek. This structure had been identified as having a very high scour potential. The underwater inspection included a standard dive inspection, geophysical survey, soil sampling, side scan sonar imaging and multi-beam survey.