# slopeStability: Slope Stability In geotech: Geotechnical Engineering

## Description

These functions are used to determine the factor of safety against shear failure on slopes using infinite slope analyses (FSinf) or planar failure analyses (FSplanar).

## Usage

 ```1 2``` ```FSinf(c, phi, gamma, gammaW = NA, alpha, D, zw, metric) FSplanar(c, phi, alpha, L, W, u) ```

## Arguments

 `c` soil cohesion `phi` soil friction angle (degrees) `gamma` soil unit weight `gammaW` unit weight of water (default = 62.4 pcf for English units; 9.81 kN/m^3 for metric units) `alpha` slope angle (angle of failure plane) for infinite slope analysis; angle of failure plane for planar failure analysis (deg) `D` depth to failure plane `zw` distance of groundwater table above failure plane (use 0 for a dry slope and D for a submerged slope with parallel seepage) `metric` logical variable: TRUE (for metric units: kN/m^3) or FALSE (for English units: pcf) [this is needed if gammaW is unspecified] `L` length of failure plane (planar failure analysis) `W` weight of slope per unit width (planar failure analysis) `u` average pressure head on the failure plane (planar failure analysis)

## Details

• The assumptions of infinite slope analyses include (Coduto et al., 2011):

1. The slope face is planar and of infinite extent.

2. The failure surface is parallel to the slope face.

3. Vertical columns of equal dimensions through the slope are identical.

• For planar failure analysis, the angle of the failure plane is generally not equal to the failure angle. The geometry of the failure wedge is specified using its weight, W.

• Either English or metric units can be used, but must be consistent.

## Note

See a geotechnical engineering textbook such as Coduto et al. (2011) for more background on slope stability theory.

## Author(s)

James Kaklamanos <[email protected]> and Kyle Elmy <[email protected]>

## References

Coduto, D.P., Yeung, M.R., and Kitch, W.A. (2011). Geotechnical Engineering: Principles and Practices, Second Edition. Pearson: Upper Saddle River, N.J.

geotech documentation built on May 29, 2017, 11:52 a.m.