A raft (mat) foundation is preferred over individual footings when:
Choose the correct answer
Soil bearing capacity is very high
Total footing area would exceed 50-70% of the floor area, OR differential settlements are large, OR individual footings would overlap
Rock is present at shallow depth
Load per column is very small
Correct Answer
B. Total footing area would exceed 50-70% of the floor area, OR differential settlements are large, OR individual footings would overlap
AI Detailed Explanation & IS Code Reference
Unlock the reasoning, formula path and code-linked notes inside your student dashboard.
Raft foundation covers entire building area, distributing load over large area. Advantages: lower bearing pressure, reduces differential settlement, resists hydrostatic uplift, suitable for weak soils. Types: flat mat, beam and slab, rigid, cellular raft. Designed by conventional or soil-structure interaction methods.
ScoreCardAI links this solution with subject, topic and difficulty signals so your scorecard can identify weak areas after a full mock test.
Practice more Civil Engineering questions
This MCQ belongs to AE Level Premium Test Series. Full tests include timed attempts, rank comparison and subject-wise analysis.