A foundation rests on which of the following?
Try it first: pick an option, then read the explanation.
Correct answer: D. both sub grade and foundation soil
Asked in SSC JE 22/01/2018 (Morning)
Detailed Explanation
Two parts make up a foundation system: the foundation itself (the structural part, such as a footing) and the foundation soil or bed on which it is placed. The soil immediately beneath is also called the subgrade.
Why “both sub grade and foundation soil” Is Correct
The foundation transfers the load to the ground directly below it. That ground is referred to as both the subgrade and the foundation soil, so the foundation rests on both — option (d).
Why the Other Options Are Wrong
- A. base of the foundation: The base is part of the foundation itself, not what it rests on.
- B. sub grade: Correct but incomplete; the subgrade is also the foundation soil.
- C. foundation soil: Correct but incomplete; the foundation soil is also called the subgrade.
Key Point
Foundation → rests on foundation soil / subgrade (the foundation bed).
Key Concepts for Students
- The term ‘foundation bed’ is also used.
- In pavements, the subgrade is the natural soil under the pavement layers.
- Subgrade strength is measured by CBR or plate load tests.
Practice more: this is question 30 in Shallow and Deep Foundation MCQs – Part 2. Try the whole set and check every answer instantly.