Using this page user can roughly estimate the stable slope based on the design chart proposed by Fang et al. This chart is prepared based on a series of limit equilibrium analyses, and should be only used as a rough estimate since it does not take many parameters such as groundwater level, surcharge, etc. into consideration. 

 

Soil and Slope Parameters

Enter friction angle, unit weight and cohesion of soil along with slope height and backslope angle. Please notice that safety factor will be applied on Tan(Φ). Press Calculate button when you entered all data.

 

Stability Factor and β

Ns or stability factor is calculated based on slope height (H), soil unit weight (γ) and soil cohesion (C) as shown below:


 

This parameter is a key factor for estimating the angle of slope stability. Ns is interpolated from the results of a series of limit equilibrium slope stability analyses carried out by Fang et al. (see below).