Ground Anchor Bond Stresses v water table

[dcarr82775]

All of the work I do involving ground anchors has been above water table. I am looking at a project where I will need to design anchors below water table (cutoff wall).

Does the water table have much of an effect on the anchor bond stress to the soil?

Thanks

 

[PEinc]

I have never reduced the anchor bond value for being below the water table. I have also never seen anyone else do so.

http://www.PeirceEngineering.com

 

[ItsOnlyDirt]

I guess it depends on the the material and the way you calculate it, i.e. effective stress is sands or reduction factor on say a cohesive material/rock.

As PEinc says the latter it wouldnt affect.

 

[PEinc]

The water table can more greatly affect the installation of the anchor than the bond stress.

http://www.PeirceEngineering.com

 

[ItsOnlyDirt]

Therefore potentially loosen the material around the bond length. In which case pressure grouting would be the way to go ??

 

[PEinc]

Possibly. But more likely you would get soil running up into the casing pipe which could prevent the tendon from remaining in place when the casaing is pulled. This would more likely happen if you flush with air when drilling below the water table.

http://www.PeirceEngineering.com

 

[InDepth]

There are several papers if you google search bond stress reduction and water table. I typically specify a creep stress when I have a water table condition.