A New Stability Analysis Method for Loess Slope Based on Logarithmic Spiral Curve

To overcome the problem that the approximation error of the slip surface feature is bigger when using traditional methods to analyze the stability of loess slope, a new method is put forward. At first, the mathematical model was used to simplify the slip surface of loess slope as logarithmic spiral shape, and then the formula of stability coefficient was deduced to establish the mechanical analysis model of instability slope. At last, the variable-step optimization algorithm was adopted to calculate the minimum stability coefficient. The application instance shows that using logarithmic spiral curve to fit the slip surface feature can conform with the practical failure characteristic of loess slope closely. The variable-step optimization algorithm proposed can improve both convergence rate and accuracy, and its computation results are exactly consistent with the actual facts of loess slope.