Multi-Segmental Liner Proves to be the Solution in Detroit
Founded in 1984, Channeline began manufacturing structural fiberglass, non-circular sewer liners, with the focus of manufacturing the egg-shape sewers of the United Kingdom and Europe. The company was extremely successful in this market and as the brand grew both locally and internationally, it became apparent in order to maintain this momentum, its technology needs to be specified for larger sewers and culverts.
From the successful development of large-diameter, custom-fabricated pipe liners, Channeline discovered a new dilemma: How do you ship these pipe liners when they don’t fit into a standard shipping container?
“The solution we found [was a] tapered tongue and groove jointing system. This system offered a way to break the geometrically complex pipe liners down into multiple component segments, while still maintaining structural integrity and load capacity when finally installed,” explains Channeline International senior vice president Tim Webb.
Channeline patented this proprietary jointing system back in the 1990s and found that it was not only able to ship for increasingly larger projects, but it could also reduce the overall shipping cost of the lining system by reducing the number of containers required.
In many cases with large structures, it is desirable for the pipe panels to be manufactured into two or more sections specifically because of the ease of shipping and drop in price. These panels are then bonded onsite using a proprietary structural adhesive aboveground. Once the segments are assembled, the Channeline GRP Structural Lining System provides the same structural performance of a Channeline manufactured single piece pipe with a stand-alone service life of 100 years.
Things have come a long way since the 1990s and the tapered tongue and groove jointing system has additional benefits, not only in reducing shipping costs, but for rehabilitation projects that have difficult access such as lining through manhole or maintenance chambers, where the same structural liner can be installed using fully trenchless methods.
Oakland-Macomb County, Detroit Case Study
A new milestone was the inclusion of the multi- segmental liner in a pilot project for the North Interceptor, East Arm (NI-EA) PCI-4, Oakland-Macomb County in Detroit, for a 17.5-ft diameter tunnel with a 16-ft ID liner.
The NI-EA was constructed in six contract sections over a period from 1969 until 1978. The NI-EA conveys sanitary and combined sewer flows from the Oakland and Macomb County communities serviced by the Oakland Macomb Interceptor Drain Drainage District (OMIDDD) north of the City of Detroit, the interceptor has an approximate total length of 79,380 ft.
In April 2015, NTH engineering was engaged by DWSD to perform a confined space entry inspection of the portion of the NI-EA. The distress noted during the inspection of the sewer included; loss of concrete liner thickness up to 6 in. in depth at locations along the crown of the sewer, exposed circumferential and horizontal reinforcing steel, along with scaling and cracks.
Based on the observed deterioration of the interceptor, recommendations were given to repair the first 1,500 ft of the NI-EA extending downstream from the Northeast Sewerage Pumping Station (NESPS) Gate House. In 2017/2018, The first 110-ft section, which showed significant distress, was repaired using a 3-in. spray-in-place pipe liner (SIPP).
In 2019, an NTH Engineering led team was engaged by OMIDDD to perform another confined space entry inspection of the portion of the NI-EA sections to provide an updated condition assessment of the existing interceptor. Using the NASSCO Pipeline Assessment Certification Program (PACP) inspection reports and photographs, NTH compared the 2019 observed conditions with historical inspection data presented in the Jan. 8, 2016, NTH report. The overall condition of PCI-4 sewer reaches was considered fair to poor.
In June 2020, the pilot project was put out to bid for 1,560 lf of the PCI-4 Interceptor and Channeline was specified as a mandatory rehabilitation method. Low-bid contractor Marra Services of Cleveland, Ohio, chose Channeline to supply 1,280-lf of multi-segmental fiberglass liner with the proprietary tapered tongue and groove jointing system. This also included a six-degree curve section in the center of the section. The liner is a four-piece multi-segmental lining with a 16-ft internal diameter, having been designed using AWWA M45 Direct Bury calculations, the liner has a 3.54-in. wall thickness.
“As far as we are aware, this the largest fiberglass sewer liner ever built to date, this was a huge challenge for Channeline, but I was confident in my team and the Channeline product to get this done and exceed expectations,” says Webb.
As each assembled section weighs more than 6 tons, Marra Services was flown over to Dubai to visit the factory and work with the manufacturing team to fine tune the assembly and installation process and spent the week getting to know the Channeline Team. Following the award and Technical Submittal stages, production of the liner started in May 2021 and container deliveries started to arrive at site in August 2021. The liner segments were shipped standing upright on pallets and Channeline were able to fit 4.5 total liners per container.
During the initial inspection and cleaning works it was noted that the previously installed SIPP liner was showing signs of severe deterioration, due to the high levels of HS and low PH levels. A decision was made to add this section to the contract and reline the 110 ft with Channeline Structural GRP. This additional liner included a 12-ft-by-14-ft, 3-in. to 16-ft ID tapered liner section to transition from the Gate House Chamber Inlet to the new liner.
The segmental liners were assembled onsite using a temporary paved level staging area installed by Marra Services and specially rigged for safe handlining into the access shaft, the entire construction footprint was less than 150 ft. One of the main challenges from a construction standpoint was how to move and install the liner, which had to travel the 1,500 ft into the tunnel. Marra Services employed the services of Kelley Engineering to custom design and build a self-driven robotic pipe carrier that transported each segment and is designed to position and home the gasketed joint for a fully sealed lining system. The contractors were able to install an average of four segments per day and are grouting the annulus every 100 ft as an additional safety measure.
“We like using Channeline due to the versatility and custom design of the product,” says Marra Services president and CEO Nick Marra. “This made a very challenging project much easier as Marra were able to work closely with the Channeline design team to tweak the GRP lining system for ease of handling and installation. In particular, the curve and tapered transition piece had everyone scratching heads, but with close team work we were able to come up with a robust solution that worked really well.”
Andy Sherwin is the technical sales director (NA) at Channeline International.