A natural slope is 35 meters high and the slope inclination is

2(H):1(V). The slope’s properties are: c′ = 50 kN∕m², ′ = 25°, and =

19.0 kN∕m² .No firm layer was encountered beneath the slope during

the subsurface investigation. Downward steady seepage that is

parallel to the slope surface occurs in the slope. The average pore

water pressure ratio for the slope was determined to be 0.4.

(1) Use Bishop–Morgenstern method to determine the minimum fac-

tor of safety (FS) for the slope.

(2) Use Spencer charts to determine the FS.

(3) Use Michalowski charts to determine the FS.