一、概述当坝基或坝体含有软弱夹层时,一般情况下假定为通过软弱夹层的复式滑动面的滑动破坏(见图1)要比假定为圆柱面的滑动破坏更危险。这种复式滑动,一般称为非圆弧滑动。计算稳定安全系数极值分布规律时,复式滑动面ABCD的两端AB和CD可为圆弧,称为改良圆弧法,也可以为直线或折线,称为楔体法或滑块法。图2是某工程的施工围堰,在 I. INTRODUCTION When a dam foundation or a dam contains a weak interlayer, the sliding failure (see Figure 1), which is generally assumed to be a compound sliding plane through a weak interlayer, is more dangerous than a sliding failure assumed to be a cylinder. This compound sliding, commonly known as non-circular sliding. When calculating the law of the extreme value of the stability and safety factor, AB and CD at both ends of the compound sliding surface AB can be arcs, called modified arcs, or straight lines or broken lines, called wedge or slider methods. Figure 2 is a construction cofferdam, at