Hydrostatic test for a Steel Tunnel Liner
Hydrostatic test for a Steel Tunnel Liner
(OP)
Hello everybody:
According to ASCE, “Manuals and Reports on Engineering Practice N° 79”, hydrostatic testing is not a mandatory requirement for penstocks; but, for one or another reason, almost always the hydro test is performed.
Here I go with my queries: that aforesaid remark applies as well to steel tunnel liners? Can the hydrostatic test be substituted by non-destructive examinations (radiographic, ultrasonic or magnetic-particle)? Or simply, for plain cylinder pipe steel linings the hydro test is not required at all?
Only as a manner of reminder, a steel tunnel liner is required to prevent the migration of tunnel leakage and over its external surface is injected low shrink backfill concrete to fill the annular space between the steel lining and the excavated rock surface.
Any comments will be welcome. Thanks
According to ASCE, “Manuals and Reports on Engineering Practice N° 79”, hydrostatic testing is not a mandatory requirement for penstocks; but, for one or another reason, almost always the hydro test is performed.
Here I go with my queries: that aforesaid remark applies as well to steel tunnel liners? Can the hydrostatic test be substituted by non-destructive examinations (radiographic, ultrasonic or magnetic-particle)? Or simply, for plain cylinder pipe steel linings the hydro test is not required at all?
Only as a manner of reminder, a steel tunnel liner is required to prevent the migration of tunnel leakage and over its external surface is injected low shrink backfill concrete to fill the annular space between the steel lining and the excavated rock surface.
Any comments will be welcome. Thanks
El que no puede andar, se sienta.





RE: Hydrostatic test for a Steel Tunnel Liner
http://www.fhwa.dot.gov/reports/centralarterytunne...
RE: Hydrostatic test for a Steel Tunnel Liner
I beg your pardon cvg if I do not follow your answer but, the hydrostatic test is intended to be performed to check for leakage through the welding beads of the steel pipe that will be manufactured from steel plates.
By the way, reading the Sec. 5.2 Test Procedures of AWWA C200 - 97, it says: "NOTE: By agreement between the purchaser and the manufacturer, other non destructive test methods may be used in lieu of the hydrostatic test". This proposal is for test in penstocks.
El que no puede andar, se sienta.
RE: Hydrostatic test for a Steel Tunnel Liner
RE: Hydrostatic test for a Steel Tunnel Liner
RE: Hydrostatic test for a Steel Tunnel Liner
Some Engineers probably use some guidance from all these references as they see fit. That being said, I think the OP probably doesn't find exactly what is needed or wanted with regard to practical acceptance (testing etc.) specifically of tunnels in these references, and I agree w/ apparent inference of cvg (that Big job he linked to might could have benefited from something more effective to end up with better results?)
RE: Hydrostatic test for a Steel Tunnel Liner
Thank you for your feedback. In a general manner, the layout of the project is as follows: at the end of the power tunnel of 2.660 m, the last 150 m will be lined with a plain pipe of structural steel plates.
Downstream, connected to this steel tunnel liner will be installed a butterfly valve (for safety of the penstock) and then, coupled to the valve, it will be welded the upper part of the penstock (properly said) of 550 m in lenght.
The hydrostatic test for the penstock is out of discussion. But the original question is regarding with the need for a hydrostatic test for the steel tunnel liner. Is it mandatory or not to do so? or, is it accepted to perform other substitute checks, tests or controls in order to give a Final Acceptance of this structure?
Once again, thanks to all.
El que no puede andar, se sienta.
RE: Hydrostatic test for a Steel Tunnel Liner
If you are the end user, or the general contractor , I would expect to focus on the quality of the grouting work that is done after the low shrink concrete has been placed. If this grouting is done properly, then the end user, contractor or engineer should not care if the steel pipe leaks like a seive , because the grouting will have sealed all the available leakage paths and water leakage is therefor zero.
RE: Hydrostatic test for a Steel Tunnel Liner