Sewer system rehab completed in historic downtown Fort Worth
In historic downtown Fort Worth, Texas, a 100-year-old stacked stone storm drain system needed immediate attention due to a deteriorated pipe. The pipe was creating voids that threatened to collapse the street surface above.
The fast-track project came with a 90-day installation deadline and multiple complicating factors. Chief among them was the arched shape of the 48- by 42-inch host pipe, a form outside the comfort zone of most modern rehabilitation technologies. Additionally, work at the site was restricted from 9 a.m. to 4 p.m.
The construction zone had to be cleared every afternoon to accommodate rush hour traffic at both ends of the day. For the same reason, manhole work at key intersections was limited to nighttime. And, with no way to bypass the system, live flow conditions were present 24/7.
O’Fallon, Ill.-based SAK Construction offered a sewer repair concept to Fort Worth officials. The repair involved using a circular-shaped Spiral Wound Rehabilitation (SPR) solution with steel reinforcement within the pipe profile. The repair would feature a cement-like cellular grout that filled both the annular space and voids behind the host arched stone pipe, to produce structural enhancement. In essence, the solution SAK recommended – at a cost 20 percent less than other technologies bid – was a concrete pipe with a PVC insert.
Using SPR technology, SAK restored the integrity of the sewer line with little to no disruption while meeting all scheduling requirements. Since SPR equipment sets up and disconnects quickly, SAK could remove the equipment and traffic controls, replace the manhole cover and leave the work zone ready to accept rush hour traffic. SPR requires no trench, bypass or cure-time, so the contractor, SAK, could disappear every afternoon without a trace. The image to the left shows sewer flow in downtown Fort Worth before the SPR rehab was completed by SAK Construction.
The repair plan was successfully executed daily. There was no traffic disruption during the repair process, says Adilda Cazorla, Fort Worth construction inspector. “We went through this difficult project with zero complaints. 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.”