Question

Calculate imposed load on roof truss of span 20m with slope of 20^o.

(a) 0.75 kN/m^2

(b) 0.95 kN/m^2

(c) 0.45 kN/m^2

(d) 0.55 kN/m^2

This question was addressed to me during an interview for a job.

Question is taken from Characteristic Loads in chapter Structural Analysis, Loading and Load Combinations of Design of Steel Structures

Answer 1

Right option is (d) 0.55 kN/m^2

For explanation I would say: As per IS 875, for roofs of slope greater than 10^o, the imposed load is reduced by 0.02 kN/m^2  for every degree rise in slope.

Therefore, Imposed load = 0.75 – 0.02*(20^o-10^o) = 0.55 kN/m^2.