关键词: 边坡稳定性, 安全系数, 计算方法, 圆弧滑动面, 任意曲线滑动面

Abstract: Based on two types of sliding surface, arc and arbitrary curve, the calculation methods of slope stability, including Sweden method, simplified Bishop method, simplified Janbu method, corrected Janbu methods, Morgenster-Price method, Sarma method and unbalanced thrust force method, are studied. Research results of above-mentioned methods are summarized. At the same time, four forms in Morgenster-Price method inter-slice force function f(x) are chosen, i.e. the constants of 0.1, 0.5, 1.0 and semi-sine function, and the formula in unbalanced thrust force method is improved. Through comparing some examples and analyzing the characteristics of these methods with different slice numbers slope angles, slope heights, and the conclusions can be obtained as follows: the factor of safety (FOS) calculated by Swedish method and simplified Janbu method is the least, and the results obtained by simplified Bishop method and the unbalanced thrust force method are quite close to the corrected method. The FOS calculated by arbitrary curve sliding surface method is slightly smaller than that of circular sliding surface method; and the critical sliding surface got by this method is close to the critical circular sliding face; so it shows that circular sliding surface, as an approximation of the critical sliding surface, can meet the need of practical engineering. Adopting a small amount of slices can obtain high accuracy of FOS in homogeneous slope; and a certain number of slices are needed to ensure reliability of the results in heterogeneous slope. In Sarma method assumption for the normal force and shear force on the side of slices makes calculated FOS larger than that obtained by other methods in homogeneous slope; then there are unsafe considerations, but Sarma method can consider the impact of heterogeneity in slope on slice method. When the slope shape (such as slope angle, slope height) changes, difference of FOS calculated by corrected Janbu method under two types of sliding surface is small; but the difference of FOS calculated by other methods is slightly larger. In Morgenster-Price method inter-slice force function f(x) has little effect on the calculated results.

Key words: slope stability, factor of safety (FOS), calculation method, circular sliding surface, arbitrary curve sliding surface