$2-$ A fill wall is needed to maintain the grade difference of a highway. The cantilever reinforced cast$-$in$-$place $($CIP$)$ wall shown in Figure $1$ was selected. The base soil and the backfill have the same properties. Evaluate the wall design for the ultimate limit state. Assume a wall length of $30ft$ in evaluating the bearing capacity of the wall. Make reasonable assumptions as needed regarding parameters not provided.

How does the stability of the wall change if the passive resistance of soil in front of the wall is incorporated?

Figure $2$: Cantilever wall for Problem $2.$