- Buyer's guide
Ongoing Rehab In Indianapolis
Shotcrete was the method of choice when the pipes had voids too large to bridge with CIPP which would prevent the bag from inverting properly or might expand into the voids, or when there were odd-shaped pipes that the lining companies could not accommodate.
“For example,” Hanas said, “there were ‘horseshoe’ shaped sewers with a concrete base and brick cap that were shotcreted because the lining company could not guarantee their liner would expand into the corners and adhere to the host pipe.”
Another technique used on a limited basis was the application of poly-based products to manholes that showed signs of hydrogen sulfide related deterioration.
“Poly products generally had not been used by the department of public works,” Hanas said, “but CEG sees value in poly products for targeted applications.”
Surface conditions of the year’s projects varied widely and most were not suited for open-cut construction.
“The large, combined sewers tended to be close to downtown and under well-developed and well-traveled roads,” Hanas said. “Buried manholes, bypass pumping and maintenance of traffic were major challenges of the large diameter projects. Our smaller diameter sewers were in neighborhoods and sometimes under easements in yards; so much more focus was placed on minimizing the project footprint and proper restoration of disturbed areas.”
Four projects illustrate the diversity of work completed during the year.
Fletcher Street Siphon – This was rehabilitation of a large, combined triple barrel siphon under eight lanes of Interstates 65 and 70 on the near east side of Indianapolis. The siphon consists of 24-inch ductile iron and 48- and 60-inch concrete barrels that convey sewage under approximately 500 feet of interstate highways.
“The Indiana Department of Transportation (INDOT) decided to conduct an emergency project to lower the pavement by approximately two feet after having a significant number of vehicles striking the overhead bridges due to height restrictions,” explained Hanas. “The cover over the siphon already was minimal – approximately six feet – and there was concern that construction activity above the siphon would cause it to break. CEG engaged Layne Inliner LLC to complete CIPP rehab of the siphon barrels prior to INDOT commencing work on its project.”