Question

In limit state design, the values of consideration of factor of safety for concrete and steel, respectively, in limit state design are:

1. 1.50 and 1.17
2. 2.00 and 1.70
3. 1.50 and 1.15
4. 1.50 and 1.50

Answer 1

Correct Answer - Option 3 : 1.50 and 1.15

Explanation:

The Acceptable limit for safety and service ability requirements before failure occurs is called a limit state.

It is further divided into two parts:

Limit state of collapse: It deals with strength and stability of the structure under maximum design load.

As per Clause 36.4.2 of IS 456, the material partial safety factor (γm) for concrete and steel should be taken as 1.5 and 1.15, respectively when assessing the strength of the structures or structural members employing limit state of collapse.

Limit state of serviceability: It deals with the deflection and cracking under service loads, durability, stability, fire resistance etc.