The Job
This WWTP tunnel curtain grouting project is located in Syracuse, New York. It is located immediately adjacent to the southern shore of Onandaga Lake in an area that is historical infill.
The Challenge
A 700 foot long, 17 feet deep utility tunnel runs through the treatment plant site. Inside are numerous site utilities, including large diameter waste lines, along with many smaller diameter chemical and treatment lines.
Over time, the tunnel walls have developed leaks, accentuated by the highly variable fill material outside of the structure. When it rains, water enters the tunnel, which has roughly three feet of cover.
The Solution
As part of a large project at the plant, plans call for curtain grouting the length of the tunnel with polyurethane grout. Curtain grouting can be done two ways:
- through the structure walls, using holes drilled through the structure, or
- from the surface, using tubing inserted down along the exterior face of the wall
In this case, the interior walls of the tunnel were not uniformly accessible due to the number of utilities mounted on the wall. CJGeo designed a grouting program using the sacrificial tubes from the surface method. The advantage of this method in this case was that the density of utilities on the inside face of the structure didn’t affect the ability to uniformly introduce grout along the outside surface of the structure.
A CJGeo chemical grouting crew placed nearly 1300 gallons of single component polyurethane resin on this WWTP curtain grouting project. The work took about three weeks start to finish. The general contractor had removed the backfill and installed a new waterproofing membrane over the tunnel lid and extending down the walls about one foot on each side.
Speak With An Expert
Facing a similar challenge to this WWTP tunnel curtain grouting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.
