PE Civil Practice Test 6

A cantilever retaining wall with an 11-ft-wide base is checked for sliding by ASD. Per foot of wall, the stem weighs 3.6 kips, the base slab weighs 4.1 kips, and the soil over the heel weighs 8.4 kips. The horizontal active thrust is 5.9 kip/ft, and the active thrust has no vertical component. The base rests on dense sand with φ′ = 30°, and the base-to-soil interface friction angle is δ = 24°. The designer neglects the 1.5 kip/ft of passive resistance in front of the toe because that soil may be excavated later. The factor of safety against sliding is most nearly: