The Job
This multiplate tunnel grouting project is located in Asheville, North Carolina. During a real estate transaction, civil engineers walked a 1400LF run of 14′ diameter multiplate tunnel running underneath a strip center and multiple outparcels.
A previous inspection had indicated impending section loss of the pipe due to corrosion and had recommended grouting of incidental voids, but no work had been performed at that time.
The pipe, which had up to 20′ of cover, bypasses a large stream and runs under 200LF of building footprint, the main entrance roadway, two out-parcels, and ties into an NCDOT box culvert to discharge.
The Challenge
Significant debris was present in the pipe, and access was exceptionally difficult. Because dewatering was not practical, all work proposed had to be performed underflow.
The Solution
CJGeo proposed polyurethane backgrouting using plural component CJGrout material, specifically CJGrout 35NHV61.
CJGrout 35NHV61 is a hydro insensitive, moderate mobility grout. It’s designed for backgrouting in wet environments, and is certified for potable water contact.
Despite a bear wandering into the pipe during repairs, CJGeo crews successfully backgrouted the pipe to address piping and erosion outside of the structure over a period of two weeks. More than 40,000 pounds of CJGrout 35NHV61 were needed for this 14′ CMP repair project.
Speak With An Expert
Facing a similar challenge to this multiplate tunnel 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.
