Invert, The lowest visible surface, the floor, of a culvert, drain, sewer, channel or tunnel. (from the dictionary of Civil Engineering, John S. Scott)
I'm not sure what context you mean when refering to "right of way". Please clarify and I might be able to help
Regards,
Tonks
It might not be just the joints that allow the methane to enter the pipe. I've come across some porous concrete pipes in the past. A suitable method of sealing the joints and the barrel of the pipe needs to eliminate/minimise the need for man entry. A suitable method might be a cured in place...
Pardal,
I understand now, you are indeed refering to a percolating (or trickling) filter usually used for the biological treatment of sewage after primary settlement.
A common term for the "filler" you are looking for is simply "filter media". As BertGielen suggests, a...
5" isn't really all that thick. Achieving a consistant thickness when shotcreting is difficult enough - don't forget about the mimimum cover to the steel in order to satisfy durability requirements. Without some margin for variation, you could have little or no cover is some places. I...
Pardal,
I'm not sure what you mean by "Digestor". Is this a digestor for sludge treatment or are you refering to a percolating/biological filter for treatment of sewage?
Regards,
Tonks
I would be particularly worried about the soft silty clay. Even though the bearing capacity might not be exceeded by your raft foundation, this sort of material may be subject to settlement through consolidation by underdrainage. In other words, any reduction in ground water levels will...