Problem $\backslash$#$3$:

A simply supported beam spans $12$ meters, and cantilevers beyond the supports on each side with spans equal to $3\mathrm{.}5$ meters each.

ra$)$ Draw the influence line for the left support

b$)$ Draw the influence line for the positive moment at midspan

$($c$)$ Calculate the maximum support reaction and the maximum positive moment if a uniformly distributed load of $\backslash (9\mathrm{.}3\backslash$mathrm$\{$kN$\}/\backslash$mathrm$\{$m$\}\backslash )$ is applied. The load can be applied partially or fully.

d$)$ Calculate the maximum support reaction and the maximum midspan positive moment if AASHTO's HL$93$ truck traverses the beam. Note that in AASHTO's truck load, the distance between the two large load can vary, so select the spacing which gives the worst effect.