Spiral wound rehabilitation solution was installed for 20% less than other bid technologies
Deploying a steel-reinforced spiral wound rehabilitation (SPR) solution, SAK Construction has successfully renovated approximately 1,050 lineal ft of a 100-year-old stacked stone storm drain system in the heart of the historic central business district of downtown Fort Worth, Texas. SAK, based in O’Fallon, Mo., delivered the project for 20% less than bids from competing technologies.
The work needed to be fast-tracked with a 90-day completion timeline. The grout holding together the original 48-by-42-in. arched stone pipe was deteriorating, causing voids to form and allowing infiltration and erosion to occur in the soil around the aging stone storm sewer. This deterioration was creating serious concern that should the pipe collapse the arterial street above would also collapse. Further complicating the assignment was limited access to the line—available only via four 24-in. manholes located at busy intersections, with work at some manholes restricted to nights due to heavy traffic volume.
SAK used SPR technology to meet the 90-day schedule without disturbing the street surface or inconveniencing commuters. In the process, workers prevailed over constant live flow conditions, a restricted weekday work window of 9 a.m. to 4 p.m. and the need to “reset” the construction zone every workday afternoon to accommodate morning and evening rush hour traffic.
Upfront planning with Fort Worth’s traffic engineer and city storm water engineering coupled with SAK’s execution of the plan resulted in business commuters never experiencing any issues. The flexibility of SPR installation equipment made daily removal viable, a key to the success of the project.
To achieve structural enhancement, SAK augmented the SPR solution with a cement-like cellular grout that filled both the annular space and any voids within the host stone pipe. In essence, what SAK provided to Fort Worth was a concrete pipe with a 100-year PVC liner.
“[W]e went through this difficult project with zero complaints," said Adilda Cazorla, Fort Worth construction inspector. "The location, plus the working hour allowance, made it even harder, and it was done in less time than expected. This job, besides being trenchless, was also painless.”
“SPR was clearly the right choice for this project as it allowed for minimal surface disruption and provided a 50-year solution meeting the hydraulic requirements. SAK’s performance was excellent, as they were able to meet all of the city’s requirements and deliver the project on time and on budget,” said Michael Owen, P.E., project manager for the city.