Fredlund 2-Point (2008) Fit

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The Fredlund 2-Point dialog contains the equation parameters necessary to mathematically represent the SWCC curve. The SWCC generally has two primary defining points; namely: i) the water content and suction at the air entry value for the soil, and ii) the water content and soil suction at residual conditions. There are also two additional points that define the extreme limits on the SWCC; namely, completely saturated conditions under zero suction (i.e., saturated water content and porosity), and completely dry conditions (i.e., zero water content and a soil suction of 1,000,000 kPa). This curve allows the SWCC to be represented by physically meaningful inflection points. The benefit to these physically significant points is the exact quantification that this allows whereby this type of soil representation can then lead to easing statistical analysis. The curve is represented through the following input parameters:


Saturated Water Content:The Saturated Water Content Field refers to the saturated gravimetric water content.


Saturated Suction:The Saturated Suction field refers to the suction at which the soil is considered 100% saturated (kPa or psf).


Air-Entry Saturation:The Air-Entry Saturation field refers the the saturation at the air-entry point expressed as a percent of total saturated volumetric water content.


Air-Entry Suction:The Air-Entry Suction refers to the suction at the air-entry point (kPa or psf),


Residual Saturation:The Residual Saturation field refers the saturation level at the residual water content expressed as a percent of total saturated volumetric water content.


Residual Suction:The Residual Suction field refers the residual suction (kPa or psf).



 Click the graph button at the bottom of the dialog to display a graph.