Earthquake Engineering MCQ with answer and solution

Concept

Imposed load in seismic weight

Step-by-step solution

1. IS 1893 (Table 10): imposed load up to and including 3 kN/m² → 25%. 2. Imposed load above 3 kN/m² → 50%. 3. Here 4 kN/m² > 3 kN/m², so 50% is taken.

Explanation

Only part of the imposed load is likely to be present during an earthquake, so the seismic weight includes 25 percent of imposed loads up to 3 kN/m² and 50 percent for heavier loads. No imposed load is taken on the roof.

Why the other options are wrong

25% is for loads up to 3 kN/m². 40% and 75% are not percentages in the table.

Shortcut

≤ 3 kN/m² → 25%; > 3 kN/m² → 50%.

Common mistake

Using 25%.