Vertical Corrugated Metal Pipe (CMP) Foundations for Power Poles
When most people consider the applications of corrugated metal pipe (CMP), they envision culverts, drainage systems, storm sewers, or detention structures. However, CMP also offers a unique vertical application: caisson foundations for the replacement of power poles. This article explores the benefits and advantages of using CMP in this application.
Addressing the Demand for Power Pole Replacement
Utility companies are tasked with replacing thousands of aging power poles across both rural and urban areas. In rural locations, traditional auger drilling methods are typically suitable for excavating holes for pole installation. However, in developed urban areas, the risk of damaging existing utilities, such as fiber optic cables and other underground infrastructure, is significantly higher. To mitigate this risk, utility companies often employ vacuum excavation methods.
Vacuum excavation is faster than hand digging and offers a safer alternative to traditional augering when existing utilities are nearby. To maximize efficiency, vacuum excavation crews prepare holes several days in advance of the more costly power pole-setting crews. During this period, a stable casing is essential to maintain the integrity of the holes.
Why CMP is Ideal for Power Pole Foundations
While other casing materials are available, CORLIX® corrugated aluminum pipe—specifically in a 2 x 2/3 configuration—stands out as the ideal choice. CMP offers several advantages:
- Cost-Effective: CMP is moderately priced compared to alternative materials.
- Structural Integrity: It is sufficiently stiff to hold the hole walls in place over multiple days.
- Ease of Handling: CMP is lightweight, allowing for easy transport and installation by small teams, typically two-person crews.
These attributes make CMP an efficient and reliable choice for power pole foundations, especially in challenging environments where underground utilities are a concern.
Industry Adoption and Testing
The use of CMP in caisson foundations has been widely adopted and is now a standard practice among many utility companies. In recent years, this approach has been put to the test during severe weather events, including hurricanes, where power poles set with CMP casings performed exceptionally well, surpassing expectations in terms of stability and resilience.
Geographic Suitability and Expansion Potential
Currently, this method is particularly effective in areas with sandy soils, such as Florida. It could also benefit other regions with similar conditions, including coastal Texas, California, and other states along ocean borders. With its proven reliability and adaptability, CMP has the potential for broader application in similar soil environments across the U.S.
Conclusion
CMP, particularly CORLIX® corrugated aluminum pipe, offers a robust, cost-effective solution for power pole caisson foundations. By employing CMP in these foundations, utility companies can enhance safety, reduce installation costs, and improve resilience against natural events—proving that CMP’s utility extends far beyond traditional horizontal applications.