Stratification and its Effect on Permeability of Soil

Hi,
Permeability of the soil is an important property which allow the flow of water through it. Water effects the engineering properties of the soil, like its compaction and therefore its bearing strength.
Introduction:

Stratified soil deposits consist of layers having different co-efficient of permeability, k1, k2, k3.... and d1, d2, d3 ......... are the depth of the layers. etc.  All these values depend upon the physical and chemical properties of the soil in the corresponding layers.




We have to find out the permeability of soil in different directions.
Permeability along the stratification (x-axis):
In the x-axis the permeability is governed by the layer having maximum permeability.
Numerically,
   
    kx =  (k1d1+k2d2+k3d3 + ........) / ( d1+d2+d3+......)

Permeability along perpendicular direction (y-axis):
In a direction perpendicular to stratification, the permeability is governed by the layer having minimum permeability.
     
         ky = (d1+d2+d3+..... ) / ( d1/k1 + d2/k2 +d3/k3 +......)

Thanks for your kind visit!