Maintaining and Repairing Steel Structures

Repairing a crack without understanding and eliminating or mitigating the reason the crack occurred will usually result in the repaired member cracking again. Cracks and corrosion can cause serious problems for any type of structure, however when dealing with steel the cracks can be more costly as they will cause stress and strain curves in other portions of the building as a result.  Structural engineers should be consulted to ensure that the repair method will restore the steel structures to the desired strength and that the most effective method of repair has been chosen. Here are some examples:

• Load Carrying Replacement: Load-carrying members are usually replaced when 30% or more of the steel has been lost by corrosion or when they are deformed.
• Adjacent Replacement: If adjacent members show signs of serious deterioration, it may be more economical to replace whole frames or bents. New temporary members and adequate bracing should not remove a stressed member before transfer of load to adjoining members or has relieved the stress. In the replacing of piles, the load should be shifted temporarily to other piles by struts or beams using jacks.
• H-Piling: Reinforcement of H-piling by welding steel plates onto flanges and web may be appropriate in localized areas of corrosion. The reinforcing plates should be of sufficient thickness to restore the original strength to the piling and of sufficient area to encompass and extend beyond the extremities of the corroded area.