Figure shows the typical framing plan of a steel building. Design beam B1 and B2 as laterally Supported. Use following data for the design.

i) All beams support a brick wall of 150 mm thk. & 3m high having unit wt. $20KN/m^3.$

ii) Thk. of RCC slab is 120 mm & top flanges of the beam is embedded in concrete. Unit wt. of concrete is $25 KN/m^3.$

iii) Live load on slab is $3KN/m^2$ and wt. of floor finish is $0.75KN/m^2 $