$3$ storeys

$1$st storey stiffness $=$k$1$

$2$nd storey stiffness $=$ k$2$

$3$rd storey stiffness $=$k$3$

$3$rd storey stiffness $=$ k$4$

Find the global stiffness matrix $"$K$",$

Use unit force of $1$kN at each u$\text{'}$s$($degrees of freedom$)$ then find the solution.

Earthquake structural analysis