Question #$4[20$ pts$]$

A rigid pavement is used with a modulus of subgrade reaction of $200l\frac{b}{i}{n}^3,$ a slab thickness of $8$

inches, a load transfer coefficient of $3\mathrm{.}2,$ a modulus of elasticity of $5$ million lb$/$in ${?}^2,$ a modulus of

rupture of $600l\frac{b}{i}{n}^2,$ a reliability of $85\%,$ a standard deviation of $0\mathrm{.}30\frac{,}{{?}_{\frac{?}{?}}}\frac{?}{\text{P}\text{S}\text{I}}=2\mathrm{.}2(TSI=2\mathrm{.}5),$ and

a drainage coefficient of $1\mathrm{.}0.$ How many years would the pavement be expected to last based on

the following traffic data?

Daily traffic for pavement design:

$300$ single axles at $10,000lb$ each

$120$ single axles at $18,000lb$ each

$100$ single axles at $23,000lb$ each

$100$ tandem axles at $32,000lb$ each

$30$ single axles at $32,000lb$ each

$100$ triple axles at $40,000lb$ each