Trenchless Technology Center
Louisiana Tech University

Water Environment Research Foundation

Rehabilitation of defective sewer laterals restores impaired structural integrity and reduced hydraulic capacity of these pipes, as well as improves the leak-tightness of pipes and connections and hence eliminates or minimizes groundwater infiltration into the sewer system and/or exfiltration of wastewater into the surrounding soil. Rehabilitation also prevents root intrusion through defects into the pipes, which is a serious problem for many agencies.

Sewer laterals can be repaired or replaced either over their entire length or only in selected parts.

A number of trenchless rehabilitation methods have been developed for the purpose of lateral repair—the principal methods in use today being cured-in-place (CIP) relining products, replacement by pipe bursting, chemical grouting, and flood grouting. Robotic repairs are a relatively new method, whereas mechanical repair sleeves for sectional repair of laterals are less frequently used.

The lateral rehabilitation methods shown below are included in our database. Click on the link to see details.
CIP Relining
  CIP, Standard Liners
  CIP, Remotely Inverted Standard Liners
  CIP, T-Liners
  CIP, Short T-Liners
  CIP, Top Hats
Pipe Bursting
  Static Pull
  Pneumatic Bursting
Lateral Chemical Grouting
  Grouting, Mainline Packers
  Grouting, Push Type Packers
Flood Grouting
Robotic Repairs
  Robotic, Pressure Applications
  Robotic, Non-Pressure Applications
Mechanical Repair Sleeves
Robotic Repairs

Robotic repairs renovate lateral-to-mainline connections by applying resin to the damaged piece of pipe, where it cures into a material compatible with the host pipe and becomes an integral part of the pipe. Based on how the resin is applied (i.e., with or without pressure), robotic repairs can be carried out as (1) pressure or (2) non-pressure applications.

Before applying the resin, however, robots perform the preparation work: any protruding laterals are machined flush to the pipe wall, pipe joints and fractures are milled and ground to expose the virgin pipe material, and, in pressure applications, holes are drilled through the pipe .

Robotic repairs offer a structural repair and eliminate infiltration and root problems. Protruding laterals are cut off and recessed laterals can be reconnected. No excavation is needed and access to private property is not required thus creating minimal disturbance to homeowners. The method is most suitable where lateral-to-mainline connections are badly damaged and where break-in protruding laterals need to be fixed.

Copy Right: TTC Louisiana Tech University
Ruston, LA