ABSTRACT
The method as indicated above assumes that the critical surface of failure is a plane surface passing through the toe of the dam as shown in Fig. 10.5.
The forces that act on the mass above trial failure plane AC inclined at angle ewith the horizontal are shown in the figure. The expression for the weight, W, and the total cohesion C are respectively,
W = .!.yLH cosec fJ sin(fJ-0) 2
and C= c~ The use of the law of sines in the force triangle, shown in the figure, gives
Substituting herein for C and W, and rearranging we have
c' 1 =- cos ec{3sin({3-0) sine0 - ¢l) sec fIJ'
yH B 2 in which the subscript eindicates that the stability number is for the trial plane at inclination e.
