QUESTION $1$

Given a continuous beam in Figure $1$ below. Do the following.

$1\mathrm{.}1.$ Select one stiffness method and calculate the moments at joints $A,B,$ and $C.$ Please note the beam members have different stiffness $AB=4$I,$BC=2$I, and CD $=$ I. $(20)$

$1\mathrm{.}2.$ Using moments calculated in Question $1\mathrm{.}1.$ Calculate the reactions at $A,B,$ and C$.(5)$

$1\mathrm{.}3.$ Draw the shear force and the bending moment diagram. $(6)$

$[31$ Marks$]$