Ulteig received a 2019 ACEC/MN Engineering Excellence Honor Award for the Waterville (MN) Substation. The program annually recognizes consulting engineering firms for projects that demonstrate an exceptional degree of innovation, complexity, achievement and value.
The existing transformer at the Waterville (MN) Substation was overloaded and its 4 kV equipment was aged and deteriorating. The client requested an electrical upgrade project involving replacement of the existing 69-4.16 kV transformer with a new 69-23.9 kV transformer. During initial site visits, however, the foundations for a substation box structure were clearly in severe need of repair, reinforcement or replacement due to concrete deterioration and poor soil conditions—adding time and complexity to the project scope.
A design to mitigate clashing with existing foundations and underground cables was required—AND the entire project needed to be completed while the structure was energized.
The conditions led Ulteig to use a technology somewhat unique for the utility industry in our region: helical piles. Advantages included the ability to replace/repair foundations while the existing structure was energized, allowing us to mount new equipment stands directly to the helical pile while minimizing outages. The substation could also be left in place instead of tearing down the structures to install traditional concrete piers.
These and other advantages came into play as the team navigated challenges of construction during Minnesota’s winter polar vortex and extremely wet spring in 2019. The use of helical piles was a critical factor in allowing Ulteig to successfully deliver a finished project that will provide safe and reliable energy for the client and the communities they serve for decades to come.