River Ave Force Main Rehabilitation

LocationNorwich, Connecticut
TimelineNovember 2019 - February 2020
Construction
MethodsCCTV
Cured-in-place pipe
Mainline grouting

Scope

Michels Trenchless, Inc. performed a pipe rehabilitation repair of a sewer main that had ruptured in multiple locations. Approximately 3,000 feet of a 14-inch diameter ductile iron force main sewer was rehabilitated using pressure pipe cured-in-place pipe liner.

Upon cleaning and using CCTV in the main sewer, it was discovered that a 770-foot segment of pipe was in extremely poor condition. Due to the pipe segment's proximity to the Thames River and the local topography, the pipe was below the water table and was subject to heavy infiltration.

To successfully install the liner, the infiltration needed to be stopped. The pipe was too close to an active rail line to install dewatering wells. The average length of a grout packer is typically 1.5-2-feet long, but Michels Trenchless and an equipment manufacturer worked together to custom build a 9-foot long grout packer to successfully control infiltration.

Grout packers of this length are extremely uncommon in the industry. Additionally, it was built with special material on the bladders in order to seal the heavily damaged pipe.

The sewer main was 6-7-feet below ground level and located between the Genesee and Wyoming Railroad and Thames River on the west side and a steep hillside on the east. There was only a narrow utility easement to set up equipment and complete the work. After Michels successfully sealed the sewer main with chemical grout we were able to install a specially designed pressure pipe, glass-reinforced felt liner. This liner produced a flex modulus of over 1 million psi, allowing for a thinner CIPP composite to gain maximum flow through the force main.

Project Highlights:

First of its kind, 14" diameter, 9' long flexible grout packer
1 Million PSI pressure pipe CIPP liner
4 installations with longest section of 777 ft
Performed in January 2020 amidst near-zero temps
Parallel to and underneath a large railway system

Michels performed a pipe rehabilitation repair of a sewer main that had ruptured in multiple locations.
Approximately 3,000 feet of a 14-inch diameter ductile iron force main sewer was rehabilitated using pressure pipe cured-in-place pipe liner.
After Michels successfully sealed the sewer main with chemical grout, the crew was able to install a specially designed pressure pipe, glass-reinforced felt liner.
Due to the pipe segment's proximity to the Thames River and the local topography, the pipe was below the water table and was subject to heavy infiltration.

Pipe Rehabilitation