SSC Boring Completes Tucson Electric Power Project on Tight Deadline
When an underground construction company is faced with challenging ground conditions, a project’s successful completion comes down to innovation, determination and patience. Even when faced with a tight deadline, a contractor’s ability to stay objective and think creatively is key to the project’s success.
Such was the case with one of Specialized Service Company’s more challenging contracts, the recent horizontal auger boring performed for the Tucson Electric Power project. The power system required upgrades to accommodate the growing Tucson area, and SSC was chosen to provide essential trenchless technology services.
- SSC was required to perform 720 feet of boring under Interstate 19
- TEP planned for 24-inch installations, a logistical concern for successful boring of such a long distance; the design was later modified for a 42” casing installation
- TEP wanted the job done quickly; this ruled out hand tunneling as well
- Auger boring technology was agreed upon as the best option; installation and casing adjustments were made and SSC set out to work
- Due to the project’s complexity, length and duration, SSC owner Abe Veidmark developed a strategic pit and layout design to stay ahead of material and spoils issues
- The ground was hard and required a change in the type of bit used
- A bit broke during work in January; crews quickly fixed it and got back on track after the minor setback
- Work continued, but strain on theboring equipment led to Veidmark’s decision to use the slick lines that were installed to pump polymer
- At 517 feet, an auger shaft snapped; this happened again at 530 feet and 580 feet
- Each time, the auger was pulled out and the broken piece was removed
- This resulted in days-long delays and the decision to replace all 4-inch hex augers with 5-inch in order to alleviate the issue
- By March, when the bore was at 640’ the bore machine was at its limit and the auger broke again; SSC informed the owner that either hand tunneling or an open-cut was necessary
- Due to time constraints, the owner chose and got approval from ADOT to open cut the remaining 80’
- In just three days, SSC dug an open-cut trench, installed the full 720 feet of casing and completed the crossing
- The conduit bundles of 14-6” PVC conduits were built
- The conduit was jacked into place inside of the 42” casing
- The annular space around the conduits required grouting. Knowing the heat that grouting this length of casing would create, Veidmark created plans to plumb an ingenious cooling system that spared more delays and finished the project on a strong and successful note
To learn more about SSC Boring’s innovative auger boring capabilities, tunneling services, or small boring units for AZ projects, call 602-997-6164 to speak with a trenchless technology expert, or Contact Us Online.