Design of Beams MCQ with answer and solution

Concept

Loading conditions acting on gantry girders

Formula

NONE

Step-by-step solution

1. Gantry girders support traveling cranes in industrial buildings. 2. They experience vertical loads due to crane dead load and lifted load, lateral loads due to crane trolley braking, and longitudinal loads due to crane travel along the runway. 3. Therefore, gantry girders are designed to resist lateral, longitudinal, and vertical loads. Answer: D

Explanation

Gantry girders support overhead cranes and must resist multiple dynamic actions during crane operation. They experience vertical loads from the weight of the crane and load, lateral forces from crab movements, and longitudinal forces from crane travel along the track. Therefore, option D is correct because gantry girders are designed to resist lateral, longitudinal, and vertical loads.

Why the other options are wrong

A) Lateral loads from crane surge represent only one component of the combined loads acting on gantry girders. B) Longitudinal braking forces must be resisted alongside vertical wheel loads and lateral surge. C) Lateral and longitudinal loads exclude the primary vertical impact and dead or live loads from crane operation.

Shortcut

Gantry girders handle 3D loads: Vertical, Lateral, and Longitudinal.

Common mistake

Selecting lateral and longitudinal loads while forgetting to include the primary vertical loads.