Question

Which of the following is not considered to be a type of pile foundation ?

• A. Prest Core
• B. Caisson
• C. Grillage
• D. Bearing

Hint:

Foundation classification:
• Shallow foundations → spread footing, raft, grillage
• Deep foundations → piles, caissons, piers Grillage foundations distribute heavy loads using layers of beams near ground level.

Answer 1

The Correct Option is C

Concept: Pile foundations are deep foundations used to transfer structural loads to deeper, stronger soil layers. Common pile foundation types include:
• Bearing piles
• Friction piles
• Prestressed concrete piles
• Caisson foundations Grillage foundation, however, is a shallow foundation system.

Step 1: Analyze Prest Core.
Prestressed concrete piles are commonly used deep pile foundations. Hence, option A is considered related to pile foundations.

Step 2: Analyze Caisson.
Caisson foundations are deep foundations used especially in bridge and waterfront construction. Hence, option B is related to deep foundations.

Step 3: Analyze Grillage.
Grillage foundation is a shallow foundation system used to spread heavy column loads near the surface. It is not a pile foundation. Hence, option C is correct.

Step 4: Analyze Bearing.
Bearing piles are a recognized type of pile foundation that transfer load to firm strata. Hence, option D is related to pile foundations.

Step 5: Choose the correct option.
Grillage is not a type of pile foundation. Therefore, the correct answer is: \[ {\text{(C) Grillage}} \]