Slurry Displacement Method
Slurry Displacement Method
(OP)
I often heard of this method for installation of drilled shafts, but have never anyone explain how it precisely works.
Can anybody give me a quick summary of this??
Can anybody give me a quick summary of this??





RE: Slurry Displacement Method
Bentonite is mixed with water (on-site preferably) to a spec. gravity, and viscosity required by the exist. conditions.
Drilling in slurry produces a filter cake on the sidewall of the shaft thus discouraging influx of water, also the hydrostatic head and or downward pressure of a shaft full of slurry stabilizes the walls until such time as concrete can be placed.
This is the short version....placing concrete (w/ tremie) is a whole other topic.
Bentonite I have seen used came from Bariod and is essentially clay dust from the Black Hills of Wyoming...I think.
RE: Slurry Displacement Method
RE: Slurry Displacement Method
RE: Slurry Displacement Method
Tests have been made which show that the placement of concrete by tremie to displace the drilling support fluid does not have a detrimental effect on the bond between rebar and concrete.
In Asia it is not unsual to have bored piles (drilled shafts) constructed by this method in excess of 100m depth.
RE: Slurry Displacement Method
RE: Slurry Displacement Method
RE: Slurry Displacement Method
There have been problems with the Polymer slurry. It is no longer allowed in my work areas.
RE: Slurry Displacement Method
For bentonite the main disadvantage stated is the possible effect of debonding of the concrete to rebar, and the coating of the bore wall which affects the friction capacity of the pile. Both of these properties are enhanced by the use of polymer.
RE: Slurry Displacement Method
Just not here.
RE: Slurry Displacement Method
RE: Slurry Displacement Method
I do not have firsthand knowledge of the "settlement" problems associated with this product....only documentation of a moratorium on its use at the present time.
Apparently at several locations shafts were turned down due to obvious problems.
It may have very well been attributed to mismanagement of the operation and or said product.
Not environmental.
Have you used this product routinely with much success?