Computes the safety factor of a relatively short cut or built slope, where undrained conditions exist along a potential circular failure plane. The mode of failure is shown in the figure below, and is described by the selection of a,b and the radius r that intersect the slope and describe the slip plane.
The factor of safety is calculated by taking moments about the center of the slip circle (O):
where the resistance moment is caused by the shear resitance of the soil along the length of the potential failure plane and the activation moment is caused by the weight of the soil above the presumed slip plane.
Private Section
Example
#include <stdio.h>#include <codecogs/engineering/geotechnics/slope_safety_factor.h>int main(){double soil_c=45;
double soil_density=1900;
double H=9; // height of bankdouble slope=90;
double a=6; // horizontal distance to toe of slope// Find the vertical position of the circle that gives the lowest factor of safetyfor(double b=10; b < 40; b += 1){double R=sqrt(b*b+a*a); // assume minimum radius to toe of slopedouble F=Engineering::Soil::slope_safety_factor(R, a, b, H, slope, soil_density, soil_c);
printf("\n b=%lf Radius=%lf F=%lf",b,R,F);
}return0;
}
Output:
TODO: Need to compute
Parameters
radius
The radius r of the slip circle. Note the radius must be sufficient to reach below the toe of the slope and beyond the top of the slope. [m]
a
The horizontal offset from the toe of the slope to the center of the slip cicle. [m]
b
The vertical offset from the toe of the slope to the cetner of the slip circle. [m]
H
The height of the slope. [m]
slope
The angle of the slope. [degrees]
soil_density
The average density of the soil within the slope. [kg/m3]
soil_c
The natural cohesion (base shear strength) of the soil, . [N/m^2]
Source Code
Source code is available when you buy a Commercial licence.