Question

Why plate girder is preferred over truss girder?

(a) plate girder requires costly maintenance

(b) higher vertical clearance required for plate girder than truss girder

(c) cost of fabrication of plate girder is high

(d) cost of fabrication of truss girder is high

This question was addressed to me in homework.

I'd like to ask this question from Plate Girders & General Considerations in chapter Gantry Girders, Design of Plate Girders & Industrial Buildings of Design of Steel Structures

Answer 1

Correct choice is (d) cost of fabrication of truss girder is high

Easy explanation: When load is heavier and span is also large, either plate girder or truss girder can be used. But, plate girder is preferred because of the disadvantages of truss girder. The disadvantages of truss girder are higher cost of fabrication and erection, problem of vibration and impact, requirements of higher vertical clearance and costly maintenance.