Seepage

 

 

The Seepage model is used to define Ground Material Properties in the Seepage Module.

Applicable Modules:

Tunnel

Slope

Soft Ground

Foundation

Seepage

Dynamic

 

 

 

 

General Parameters

Hori. Permeability Coeff. (Kh)

The coefficient of permeability in horizontal direction.

Ver. Permeability Coeff. (Kv)

The coefficient of permeability in vertical direction.

Vol. Water Content (V.W.C.)

It is the quantity of water contained in the soil, defined on a volumetric basis.

Unsaturated Property

Click to invoke the Unsaturated Property Function. The function may either be of type independent (P-K/WCC) or relation (T-P/T-K or Sr-P/Sr-K).

Name

Type the name of the function.

Function Type

Choose the type of Unsaturated Property Function from the following three types

P-K/WCC (Pressure Head-Permeability Coefficient Ratio/Water Content Characteristic) [more...]

Permeability Function

The Permeability Coefficient for the unsaturated soil is a function of water content ratio. It decreases with a decrease in water content ratio. Since, water content ratio is a function of pore water pressure and hence, the permeability coefficient is a function of pore water pressure.

 

Function Type

Select the type of Permeability Function.

Gardner Coefficients

Rk

Gardner Coefficient

a,n

Parameters

 

Frontal Function

K Ratio

Approximation for Residuals

Ho

Head pressure (suction)

 

Van Genuchten

Rk

Permeability ratio

a,n,m

Parameters

 

User Defined

The user can define the coefficients directly.

Pressure

Pore Pressure

K Ratio

Relative coefficient of permeability

 

Water Content Function

In Seepage Analysis, the amount of water retained in the soil structure can be expressed in terms of Volumetric Water Content. The curve between Volumetric Water Content and the pore water pressure is known as the Water Content Characteristic curve. If the pore water pressure is positive, the slope becomes equal to the Compression Coefficient (for 1D consolidation).

Function Type

Select the type of Water Content Function.

Van Genuchten

Thetaw

Normalized volumetric water content or relative degree of saturation.

Thetas

Saturation Volumetric water content at natural saturation.

Thetar

Residual volumetric water content

a,n,m

Parameters

 

User Defined

The user can define the variables directly.

Mv

Mv is the coefficient of volume compressibility. It is the slope of water content vs. pore pressure graph.

When the option is (a) checked off , the slope of the WCC for the saturated soil is extrapolated from the data obtained from the unsaturated soil. When the option in (b) checked on , the input is taken for Mv. It should be noted that the reported values of Mv are very low and can be taken as 0.

Pressure Load

Pore Pressure

Water Content

Water/moisture content

 

Scale Factor

Scale Factor

 

T-P/T-K (Pressure Head-Volumetric Water Content-Permeability Coefficient Ratio) [more...]

 

Ground Type

Select the Ground Type from the database [Standard: JICE (Japan Institute of Construction Engg.)]

T-P Relationship

T-K Relationship

[G], [G-F], [GF] (JICE

[G], [G-F], [GF] (JICE)

[S], [S-F], [SF] (JICE)

[S], [S-F], [SF] (JICE)

[SF] (JICE)

[M], [C] (JICE)

[M], [C] (JICE)

User Defined

User Defined

 


<Ground Type>

 

Sr-P/Sr-K (Pressure Head-Degree of Saturation-Permeability Coefficient Ratio) [more...]

 

Ground Type

Select the Ground Type from the database [Standard: JICE (Japan Institute of Construction Engg.)]

Sr-P Relationship

Sr-K Relationship

[G], [G-F], [GF] (JICE

[G], [G-F], [GF] (JICE)

[S], [S-F] (JICE)

[S], [S-F], [SF] (JICE)

[SF] (JICE)

[M], [C] (JICE)

[M], [C] (JICE)

User Defined

User Defined

 


<Ground Type>

 

Seepage Graph Option

Specify options for permeability graph. Determine whether to draw each axis on a log scale.

Water Content Graph Option

Specify options for water content graph. Determine whether to draw each axis on a log scale.

 

Effective Porosity (ne)

It represents the porosity of the sediment deposit which contributes to the fluid flow.

Specific Storage (Ss)

It represents the amount of water which an aquifer releases from storage, per unit mass or volume of aquifer, per unit change in hydraulic head under the condition of full saturation.