Westergaard  first derived an expression for the hydrodynamic pressure exerted on the vertical upstream face
of a concrete dam subjected to a single harmonic excitation.
Seepage reduction can be accomplished by using thin cutoffs such as steel or concrete walls, impervious membrane or linings on the upstream face
, impervious cores, upstream blanket of impervious earth, partially or completely penetrating rolled earth cutoff trenches, grout curtains, and slurry trenches (Sharma, 1991).
The lag of the phreatic line depends on factors such as: permeability of soils, drawdown rate, drawdown ratio and slope gradient during rapid drawdown, the stabilizing effect of the water on the upstream face
is lost, but the pore-water pressures within the embankment may remain high.
They found that the temperature distribution on the upstream face
is mainly due to the reservoir temperature condition, while on the downstream face the temperature distribution is mainly influenced by the solar radiation.
After each four-hour test, more deposited dust was observed on the down-stream face of each heat exchanger than on the upstream face
. Thus, the thickness of the dust layer increased through the depth of the heat exchanger.
To avoid lowering the reservoir or building a coffer dam, the tower is to be constructed onshore, then floated into place for installation near the upstream face
of the dam.
In the near future, the Corps plans to inspect the structural condition of the Lusk Reservoir Dam's upstream face
using a dive team because this portion of the structure needs to be visually examined.
The project team developed an environmentally sensitive and value engineering approach comprising grout-filled mattresses to the upstream face
of the weir, placed by divers, tied into a new reinforced concrete crest beam.
* Removing and replacing the concrete over the upstream face
of the dam - $472,000;