Nondestructive Testing to Evaluate Historic Bridge Foundation

NDT Corporation under subcontract to Lichtenstein Consulting Engineers, Inc of New Jersey conducted a sonic/ultrasonic nondestructive testing investigation of the west, east and center piers of the Court Street Bridge, in Hackensack, New Jersey. The objectives of this investigation was to evaluate the quality (strength and condition) of the pier concrete and determine the approximate length of the timber pile supporting under the piers. Testing was conducted with the assistance of divers from Atlantic Engineering. This bridge is a historic structure that is to be restored and this investigation provided information about the condition of the piers to determine if they can be rehabilitated or should be replaced.

Sonic/ultrasonic measurements were made along two cross sections of the east, west and center pivot piers of the bridge to assess the internal condition of the concrete. The results of the sonic/ultrasonic measurements were presented graphically showing internal areas of high velocity/high strength and low velocity/low strength concrete. Measurements were made down to the mud-line; no information was obtained below the mud-line. Impact echo measurements made on the west pier and on the top of an exposed timber pile of the fender system indicate pile lengths of approximately 45 to 50-feet.