针对地下水条件下圆弧滑动法中总应力法和有效应力法2种计算方法的假定,指出总应力法是从土条整体极限平衡角度分析的直观方法,但仅考虑了滑弧面上的水压力,在不考虑土条侧向作用力的瑞典条分法中使得安全系数计算值显著降低,需采用修正的总应力法公式;而有效应力法是以浮力形式综合考虑土条各侧面(含滑动面)上水压力的隐性方法,虽不完全符合瑞典条分法不考虑土条侧向作用力的假设,但能较总应力法更便捷和准确地得到安全系数,且在此基础上用流网法分析渗流力对土坡稳定影响更为合理.而在考虑条间力的毕肖普法中,考虑土坡顶面水压力抗滑力矩的总应力法和考虑土条浮力的有效应力法在数值计算上完全等价,静水条件下有效应力法计算较为便捷,而有渗流作用时,则是总应力法更加方便.
Through analysis of assumptions of the total stress method and effective stress method,it is shown that the total stress method is an intuitive method on the basis of soil slice limit equilibrium.The water pressure on the slide surface is taken into account,and the lateral forces of slices are ignored in the Swedish slice method.Therefore,the calculated safety factor decreases significantly,and the formula should be modified.In the effective stress method,the water pressure on each side(including the slide surface) is considered implicitly as buoyancy.Though it does not exactly match the fundamental assumptions of the Swedish slice method,compared with the total stress method,the effective stress method is more precise and convenient for obtaining safety factor,based on which the analysis results of the effect of seepage forces on slope stability is more reasonable with the flow-net method.When it comes to the Bishop's method which considers the lateral forces of slices,the effective stress method and total stress method are totally equivalent in numerical calculation.Nevertheless,the effective stress method is more convenient in the hydrostatic condition,and the total stress method is more convenient in the seepage condition.