中文摘要：

通过绘制边坡的安全系数等值线可以得到符合指定条件的安全系数潜在滑动面的包络线。可以采用极限平衡法计算过边坡内任一指定点滑动面的最小安全系数，根据通过各节点的最小安全系数就可以绘制出安全系数等值线，由此得到安全系数空间分布特征。这种方法可以进一步推广到加速度和惯性力包络线的计算。针对简单边坡和不同平台宽度的两级边坡，论文分别给出了相应的安全系数、加速度和惯性力等值线，计算表明平台宽度较小时，安全系数和加速度的等值线分布形式与简单边坡类似，平台宽度较大时，最小安全系数和最大加速度对应的潜在滑动面倾向于分布在两个次级边坡本身之中。而惯性力等值线分布规律受平台宽度的影响较小。

英文摘要：

Envelope of potential slip surfaces of a slope at certain safety factors can be obtained by drawing the contours of the factors. For a given point in the computational domain of a slope, limit equilibrium method can be used to calculate the minimum safety factor among the potential slip surfaces passing this point. Then, safety factor contours, which show the spatial patterns of safety factors, are easily achieved after the minimum safety factors of all the LEM nodes have been calculated. This approach can be extended to calculation of those envelopes of potential slip surfaces at certain acceleration and inertial force. This paper presents the contours of safety factors, accelerations, and inertial forces calculated for a simple slope and two-step slopes with different bench widths. The results reveal that for the two-step slopes, the contours of safety factors and accelerations are similar to those of simple slopes if bench width is small, while their critical slip surfaces at the minimum safety factor and maximum acceleration tend to go through the steps of the slope if bench width is large. In contrast, the contours of inertial forces are less affected by the bench width of slopes.