Ex$.4\mathrm{.}1$

You have been asked to design a flexible pavement and the following traffic is expected

for design:

Reliability is $90\%,$ overall standard deviation is $0\mathrm{.}40\frac{,}{{?}_{\frac{?}{?}}}\frac{?}{\text{P}\text{S}\text{I}}$ is $1\mathrm{.}8,$ and the design life is

$12$ years. The soil has a resilient modulus of $13,750-(94\mathrm{.}81$MPa$).$ If the TSI is $2\mathrm{.}5,$

what is the required structural number?