Installing Foul Drainage Under an Existing Suspended Slab

[interstructeng]

Hello,

Has anyone had any experience of installing drainage runs underneath an existing piled suspended slab? The project is a renovation/change of use, where the existing foul drainage does not suit the proposed layout. So the new runs have to be installed underneath the existing suspended slab. Looking for a methodology of installation, using pipe jacking or similar. Trying to minimize any penetrations in the slab.

If anyone has come across this scenario before and has any knowledge or ideas to share it would be much appreciated.

 

[oldestguy]

Foul drainage means what? Sanitary sewer?

 

[jayrod12]

We've had contractors excavate from the outside when it has been possible with the layout. Otherwise you may have your work cut out for you.

 

[dhengr]

Interstructeng:
How about horiz. directional drilling (HDD) to a pit in the bldg.? Of course, you have to know where the existing foundations and underground utilities are.

 

[interstructeng]

oldestguy - yes that's exactly it (maybe UK terminology!)

jayrod12 - thanks for the suggestion - the building has a large footprint - some of the runs could be up to 40 meters. Excavation is definitely an option for some of the shorter runs though.

dhengr - thanks for the suggestion - I have a ground penetrating radar scan of the foundations so I can use that. I'll look into that technique - looks like a good solution.