Four Reasons to Restore (Not Replace) Steel Structures

Steel transmission structures are exposed to environmental conditions that have a deleterious effect on the structures during their service life.  Exposure to these environmental conditions causes degradation of original protection mechanisms applied to the structure during construction, such as galvanization and protective coatings.  Once these protective barriers have been breached, the steel comes into direct contact with the environment increasing the risk of corrosion and the subsequent weakening of structural components.  Once the structural integrity of a transmission asset is compromised, the condition of the structure must be restored to its original design strength or the structure must be replaced to maintain the integrity and reliability of the circuit or line segment.  Structure replacement is costly, may disturb the environment, inconvenience property owners, and impact service due to line outages.  

Restoration of steel structures and foundations in lieu of replacement will result in several tangible benefits to a utility including:

1. Value: Restoration with a fully engineered solution can be completed at a fraction of the cost of replacement.

2. Funding: A coating and restoration program significantly extends the useful life of steel towers and poles.  As a result, many utilities across the U.S. regularly capitalize their programs.

3. Risk Avoidance: Restoration provides a timely resolution of a liability, helping pole owners improve safety, with NO interruption in service to customers.

4. Hassle-Free: Unlike a replacement, restoration requires NO heavy equipment and can generally be completed in one day.

When designing transmission structure restorations, it’s important to understand the deterioration issues that impact the performance of the original design.  For example, with lattice towers, these issues include understanding the size of the damaged or corroded member, the distance between supports and bracing, the load applied overhead, and the potential load distribution between the members.  Along with these considerations, an engineer must understand the extent of the damage and analyze the structure for construction loads and intermittent loads applied during the restoration process.  The determination of load is aided using computers and finite element analysis (FEA) software.  The use of these software programs provides unparalleled information and analysis and allows for full tower and specific restoration modeling to fully understand areas of high stress and ideal areas to reinforce within the structure.  The result is the ability to restore, harden, uprate, and increase circuit reliability and resiliency without the need for structure replacement.

 

 

Structural Steel Restoration (designed and implemented to ASCE 10 specifications) can be implemented:

  • For corrosion rehabilitation to restore original strength
  • For structural hardening and line uprates
  • While the structure is temporarily supported; lines remain in service

To learn more about how Osmose can provide a steel life-extension program for your utility, please contact your local Osmose representative.  Not sure who your local Osmose representative is?  Email poleinfo@osmose.com to find out.