Anchor Bolt & Rod Inspection

Paul S. Fisk, President NDT Corporation

Anchor Bolts and Rods on
a Typical Sign or Light Tower

Many of the signs and communication towers along our highways have been in service for many years and are of an age where it is important to test their anchor bolts and rods for flaws that could affect the ability of these structures to withstand severe weather conditions. NDT uses ultrasonic testing to determine anchor rod lengths; whether anchor rods are straight or hooked; and to detect flaws in the anchor rods and bolts.

Sign, signal, and lighting structures utilize large anchor rods to provide attachment of the structure to their foundations. These structures are subject to large forces from wind and gravity - particularly cantilever structures - that are transmitted directly to their foundation carried through the anchor rod group. The inspection of roadway signs, light poles and traffic signals requires an assessment of the length, configuration and condition of anchor rods and bolts.

Ultrasonic Testing Reveals Anchor Bolt
and Rod Condition and Dimensions

Our testing data are used to evaluate the integrity and condition anchor rods and bolts for structures including:

• Traffic Signal Monotubes/Poles
• High Mast Lighting Poles
• Cantilever Signs
• Mast Arms
• Signal Supports
• Communication Towers

We also test for:

• Concrete footings and exposed pads to determine the reinforcing spacing and depth of cover
• Depth of exposed drilled shaft tower footings
• Depth of bedrock at footing locations
• Soil & bedrock compressional & shear velocity values for earthquake analysis

NDT Testing of Tower and Sign Pads & Footing