Achieving Alignment with the Sand Springs Flume Replacement
JR Merit recently completed construction to replace a 42-inch diameter flume more than 1,850 feet long near Hagerman, Idaho. The work included demolishing the existing 42-inch wooden stave pipeline constructed in the 1960s that had reached the end of its useful life and constructing a new, 42-inch spiral-welded flowline that follows the same path as the existing structure with both exposed and buried sections.
JR Merit was the prime contractor for the project, working with designer River Structures Engineering and specialty subcontractors for several aspects of construction. Our work included removal of the existing concrete supports, steel surge tank, and roadway encasement. Our team then fabricated and provided a new spiral-welded steel penstock coated internally and externally, and fabricated new pipe saddles. We excavated new pedestal locations and buried sections for the new flowline. We used both new cast-in-place and precast concrete thrust blocks. The installation included field welding and joint coatings both inside and outside the flowline. We also installed drainage culverts, new thrust blocks, and expansions joints for thermal growth and constructed a new roadway encasement.
The eight-month construction project began in late September 2021 and completed at the end of May 2022.
All Aligned
Aligning both the pipeline and the pipe saddles were critical tasks requiring a precision approach in both design and construction. In our design review, we identified concerns in the saddle design related to limited adjustability or forgiveness for alignment. We designed and proposed an alternate saddle that was approved and implemented with great success. We also discovered that the initial design was based on an old survey, which proved inaccurate during our initial quality control survey. We brought in a third-party surveyor to verify alignment and provide on-call support for re-staking and verification of changes. We managed to hit centerline on 100 percent of our cast-in-place concrete thrust blocks in relation to pipe centerline during final placement and alignment.
Working through Winter Weather
A significant challenge that our team overcame on this project was working through one of southwest Idaho’s worst snow seasons in recent years. The pipeline installation occurred in the darkest depths of winter weather in December and January. JR Merit ensured safety was the project’s top priority, devising well-thought-out safety plans and coordinating constantly with all crews.
All crews stayed safe, and the project schedule was maintained. The project only lost two days to severe weather when more than eight inches of snow fell in only 10 hours.