Q4. Figure Q4 shows a steel column that pinned on top and fixed at the base. The column is restrained by steel beams about its x-axis and y-axis on the top of the column. The radius of gyrations of the column about x-axis is 137 mm and y-axis is 77.8 mm. The Modulus Elasticity of the column is 200 x10 kPa. (i) Calculate the moment of inertia of the column on x axis and y axis. (17 marks) (ii) Find the effective length of the column about x and y axis. (2 marks) (iii) Determine the slenderness ratio of the column and choose the critical slenderness ratio. (2 marks) (iv) Calculate the critical buckling stress and axial load of the column. (4 marks)

308 mm 20.6 mm 1 1 318 mm 13.1 mm 20.6 mm PLAN VIEW COLUMN SECTION 12 m 11.7 m SIDE VIEW FIGURE Q4