Project Appreciation and Objectives
During sewer renovation, after installation of a manhole-to-manhole sewer lining, holes are cut to 're-connect' the laterals, which may in turn lead to infiltration via defective connections. To address this infiltration problem, there are two solutions which have recently become available in the UK: 'top-hat' and grouting repair systems.
'Top-hat' cured-in-place systems consist of a short cured-in-place lining formed into a 'T' or 'Y' shaped insert (for 90° or 45° laterals, respectively). This is inserted into the lateral via an inflatable packer located within the sewer and once cured forms a permanent seal between the lateral and main sewer.
Grouting systems use an inflatable packer to isolate the connection between the sewer and the lateral, and a short way into the lateral. A grout material is pumped through the packer and flows through the defective pipe work into the surrounding ground forming a seal.
There is a need to independently evaluate these new technologies to demonstrate their effectiveness. This project will develop a long term hydrostatic pressure test procedure which is applicable to the repair systems, and undertake testing on a selection of products to determine their effectiveness in reducing sewer infiltration.
- Demonstration of the infiltration reduction capabilities of repair systems so that Utilities have confidence in cost effective procurement / sewer capital maintenance
- Reduction in sewer infiltration / exfiltration and associated issues
- Test methodology / specification to prove future repair system fitness-for-purpose.