Leaks throughout the joints on a 25VF precast stormwater manhole were leaking. This caused a large sinkhole to open up at the surface, adjacent to the structure. Homeowners on either side of the easement were concerned about the stability of the area and reached out to the municipality. The estimated cost for excavating the structure to repair it from the outside exceeded $50,000.
Due to the depth of the manhole, confined space entry had to be used. Additionally, the grout had to tolerate high moisture levels in the adjacent soil, and economically fill the extensive voids. Due to the presumed large size of voids, the grout had to also be low heat.
High density geotechnical polyurethane grouting to fill the sinkholes adjacent to the structure, and seal all points of infiltration.
CJGeo polyurethane grouting crew sealed all of the infiltration points and filled the sinkholes in a single day. No excavation was required, and cost was less than 20% that of open excavation.