A sinkhole opened up in a drainage easement maintained by an HOA. The cause of the sinkhole was identified as an improperly-seated gasketed joint between two 36″ HDPE stormwater pipes. The pipes were approximately 5 feet below the surface, where there was a 3′ diameter sinkhole. The pipe had been poorly installed, so it suffered extensive ovaling due to compression of the top during compaction without lateral support.
Chemical grout injectioninto the sinkhole from the surface to fill the sinkhole and seal the pipe joint.