CIPP Rehabilitation - Cover Depth

This image shows DN300 NRCP with power conduit bored below the culvert and the pipe invert removed during bore installation. Collateral damage caused by the bore is exfiltration from the stormwater culvert resulting in subsidence of the road pavement above. The culvert asset owner is faced with these issues:

Continually repair the road pavement subsidence/damage; or

Reline the DN300 NRCP to seal the exfiltration and limit road pavement subsidence/damage; or

Replace the existing pipe culvert with DN375 RCP culvert or RCBC 375x375 which will require lowering the power conduits at significant additional cost and time.

Stormwater pipe culverts in older metropolitan precincts have been installed at a shallow depth and increased vehicle traffic loading has caused overloading of the pipe with resulting deformation and displacement which manifests as road pavement damage. Rehabilitation by CIPP relining is constrained by the pipe cover depth and vehicle traffic loading. Frequently the only permanent solution is to replace the damaged pipe culvert at greater depth or with RCBC which can withstand higher loading.