Pile Foundations MCQ with answer and solution

Concept

Specification of minimum concrete grade for durability and structural integrity of pile foundations as per Indian Standards.

Step-by-step solution

1. Refer to IS 2911 (Part 1/Sec 1): 2010 code provisions for concrete piles. 2. Check the clause regarding the grade of concrete. 3. The minimum grade of concrete specified for bored cast-in-situ piles is M 25.

Explanation

As per IS 2911 (Part 1/Sec 1): 2010 for concrete piles, the minimum grade of concrete to be used for bored cast-in-situ piles shall be M-25, and for driven precast piles, it shall be M-30. Since general piling standards refer to M-25 for cast-in-situ concrete piles as a standard baseline, M-25 is the correct standard choice.

Why the other options are wrong

A: M15 is too low for structural piling as per current IS 2911 standards. B: M20 was allowed in older versions, but current revision specifies higher grades. D: M30 is specified for driven precast concrete piles, whereas general cast-in-situ requires M25.

Shortcut

Remember that for modern structures as per IS codes (IS 456 and IS 2911), M25 is typically the baseline minimum grade for reinforced concrete structural elements exposed to severe or standard environments.

Common mistake

Confusing with older versions of codes or plain cement concrete requirements where M15 or M20 were permitted.