Uplift Pressure in Clays (Buoyantcy)

[Triaxle]

Opinions please, Saturated Clay below water table. I would think buoyant pressure may develop overtime but is retarded by low permiability (neglecting sand seams which ussually occur in horizontal bands) Have a Geotech who is concerned with buoyant pressure prior to completion of building which seems excessively conservative. Any comments would be appreciated.

 

[jdonville]

Triaxle,

Perhaps the concern is not so much with buoyancy effects as it is with increasing pore pressures during construction. These pore pressures may limit the rate of construction due to bearing capacity concerns.

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com

 

[dgillette]

A bit more information is required to understand the question. Is s/he concerned about heaving of the bottom of the exc due to pressure that is not relieved by the dewatering program?