19 June 2001
SR-2: CATHODIC PROTECTION FOR STEEL BEARING PILES
Problem: New steel bearing piles have been installed or existing piles have
experienced slight surface deterioration. Anticipated corrosion is high. Protection
against further corrosion is required.
Description of Repairs: Two methods are available for providing cathodic
protection for steel bearing piles:
Sacrificial Anode System: Secure sacrificial anodes below low water
on steel by welding or bolting. Size, type, and spacing of anodes must be
determined to suit structure and environment (see Figure 8-2). A good electrical
connection between elements must be maintained.
Impressed Current System: Install the cathodic protection system as
shown in Figure 8-2. Basic components include:
Anode: Material to be consumed over a long period of time.
Electrical potential: Power source (rectifier) to provide constant electrical
potential between anode and steel pile.
Ground between piles and power source to provide closed cell.
Application: Requires careful design and installation. System is not effective for
mitigating corrosion above mean low water.
Future Inspection Requirements: The cathodic protection system must be
carefully monitored and maintained. If anodes for an impressed current system
are placed between bents, special inspections must be made to ensure that
floating debris has not damaged or removed the individual anodes.