Problem $1$:

The frame shown is located on sloping

ground. The beam is made much stiffer than

the columns and can be assumed rigid with

total mass of $450,000kg.$ The cross$-$sections

of the three columns as shown but their

lengths are $2\mathrm{.}4m,4\mathrm{.}8m$ and $9\mathrm{.}6m,$

respectively. Determine the base shears in the

three columns due to EQ spectra assuming

$5\%$ damping ratio shown on problem $4.$

Assume $E=20,000$MPa.