- 2082 Bhadra · 2 marks
Shallow versus deep foundation
Short answer
Shallow foundations (Df ≤ B) transfer load near surface, for good shallow soil, simple construction, low cost. Deep foundations (Df > B, typically Df/B > 4) reach a deep strong stratum, handle heavy or uplift loads, cost more, require special equipment. Types: shallow - isolated, strip, combined, raft; deep - piles, piers, wells.
Differentiate between shallow foundation and deep foundation. Also, name their types.
A shallow foundation transfers load to the soil near the surface (); a deep foundation transfers load to a deeper, stronger stratum (, usually to 5 for piles).
| Point | Shallow foundation | Deep foundation |
|---|---|---|
| Depth / width ratio | (up to 3-4 in some books) | to 5 |
| Load transfer | Mainly by base bearing | By end bearing and/or skin friction |
| Suitable soil | Good soil near surface | Weak upper soil, strong deep layer |
| Construction | Open excavation, simple | Needs special equipment and skill |
| Cost and time | Low, quick | High, slow |
| Load capacity | Light to moderate | Heavy, also uplift and lateral |
| Analysis | Bearing capacity + settlement | Pile capacity, group effect, negative skin friction |
Types
- Shallow: isolated (spread) footing, wall (strip) footing, combined footing, strap footing, raft (mat) foundation.
- Deep: pile foundation (driven, bored, friction, end-bearing), pier foundation, well (caisson) foundation, drilled shaft.
✓ Answer checked by Claude Sonnet 5.5
Related questions
- Classify shallow and deep foundations · Foundation Engineering, chapter 1 · asked 4×
- When piles are preferred to shallow foundations · Foundation Engineering, chapter 8 · asked 3×
- Deep foundation types and use of shallow foundations · Building Technology, chapter 2
- Shallow and deep wells · Water Supply Engineering, chapter 2 · asked 4×
- Types of shallow foundation · Building Technology, chapter 2
- Foundation requirements and shallow foundation types · Building Technology, chapter 2