Pile Foundations MCQ with answer and solution

Concept

Minimum clear cover requirements for pile foundations as per Indian Standards (IS 2911).

Step-by-step solution

1. Refer to IS 2911 (Part 1/Sec 1)-2010 regarding reinforcement and cover in pile shafts. 2. Locate the clause specifying the minimum clear cover for cast-in-situ or precast piles. 3. The code specifies a minimum clear cover of 50 mm to all main reinforcements in the pile shaft.

Explanation

According to IS 2911 (Part 1/Sec 1): 2010 (Code of Practice for Design and Construction of Pile Foundations), the clear cover to all main reinforcements in a pile shaft shall not be less than 50 mm to protect the steel from corrosion and ensure durability.

Why the other options are wrong

A: 20 mm is too small and typically used for slabs in mild conditions. B: 30 mm is generally used for footings or mild exposure beams. C: 40 mm is common for columns, but IS 2911 strictly mandates 50 mm for pile shafts.

Shortcut

Remember that piles are underground and prone to aggressive soil/groundwater environments, so they require a higher minimum cover (50 mm) compared to standard beams/columns.

Common mistake

Confusing pile cover with standard column or beam cover (e.g., 40 mm for beams or 40-50 mm for columns, though piles specifically require at least 50 mm due to severe exposure conditions).