agus72indo
Geotechnical
- Jan 22, 2002
- 16
Dear all,
I am from Germany doing research on expansive soils. Some terms, such as coefficient of permeability, really has some doubts in its definition. As Darcy's law described that coefficient of permeability should be referred to water in its free form, i.e., those that fill the macropores of the soil. However, expansive soils exhibit double porosity, macro- and microporosity.
Suppose I saturate the expansive soil with water at certain pressure. Many findings said that as the soil is saturated, there is closure of the macropores as the result of swelling of the microstructure reducing the coefficient of permeability. Nevertheless, if we look at the smaller scale, it has been a fact that during that process, there is local transfer of water from the macro- to the microstructures, which is indeed also resulted from the existence of water potential (i.e., hydraulic gradient).
I really have some confusions regarding this thing. I would be glad if some of you can give me a kind of clarification and explanation pertaining this matter.
Regards,
Agus Samingan
Bauhaus-Uni Weimar, Germany
I am from Germany doing research on expansive soils. Some terms, such as coefficient of permeability, really has some doubts in its definition. As Darcy's law described that coefficient of permeability should be referred to water in its free form, i.e., those that fill the macropores of the soil. However, expansive soils exhibit double porosity, macro- and microporosity.
Suppose I saturate the expansive soil with water at certain pressure. Many findings said that as the soil is saturated, there is closure of the macropores as the result of swelling of the microstructure reducing the coefficient of permeability. Nevertheless, if we look at the smaller scale, it has been a fact that during that process, there is local transfer of water from the macro- to the microstructures, which is indeed also resulted from the existence of water potential (i.e., hydraulic gradient).
I really have some confusions regarding this thing. I would be glad if some of you can give me a kind of clarification and explanation pertaining this matter.
Regards,
Agus Samingan
Bauhaus-Uni Weimar, Germany
