2011 Volume 60 Issue 7 Pages 316-321
As a result of corrosion surveys, port steel structures have been damaged by splash zone corrosion at splash zone and by concentrated corrosion both at low tide level and in sea water. Corrosion damages could lead to serious reduction in strength and, in the extreme, to collapse and to unexpectedly expensive maintenance work possibly requiring total closures and consequential loss of revenue. An organic or inorganic covering method has been applied to the steel at splash zone and cathodic protection to the steel below sea water level.
When the PW method is applied to port structures, there is the strategy of designing to a low first cost followed by more substantial maintenance in accordance with the relationship between discount factors and time for different rates. The strategy would be accompanied by increased risks of unexpected maintenance requirements and lower levels of safety. When maintenance consists of repair and shutdown, shutdown costs can be higher than repair costs and tend to dominate calculation of discounted maintenance costs. Accordingly, there will be scope to design for changes in the balance between construction and maintenance costs from the economical and technical points of view.
This paper will look at the balance between first and maintenance costs, the application of the PW method to a steel pipe pile model and some problems in the application of the PW method to port structures.