$11\mathrm{.}10$ An interstate highway pavement composed of a HMA surface course, a cement treated base course, and a sand$-$gravel subbase is to be designed for an ESAL of $1\mathrm{.}2{10}^6.$ The quality of drainage is considered fair because water can be removed from the subbase within a week. However, there is a large amount of precipitation, so more than $25\%$ of the time the pavement will be exposed to moisture levels approaching saturation. The material properties' are as follows: effective roadbed soil resilient modulus $=5500$ psi, resilient modulus of subbase $=15,000,$ unconfined compressive strength of cement$-$treated base at $7$ days $=500$ psi $($see Figure $7\mathrm{.}15c$ for correlation$),$ and resilient modulus of HMA$=4\mathrm{.}3{10}^5$ psi. Assuming a minimum thickness for HMA, determine the thicknesses of the surface, base, and subbase courses required. $[$Answer: $3$ in$.,6$ in$.,$ and $9in.]$