Consider the following statements regarding the Limit State of Serviceability 1. It ensures that the structure does not collapse under the design loads. 2. It includes checks for excessive deflection and cracking to ensure user comfort and durability. 3. Partial safety factors for loads in serviceability checks are generally taken as 1.0. Which of the statements given above are correct?
- A1 and 2 only
- B2 and 3 onlyCorrect
- C1 and 3 only
- D1, 2 and 3
Solution
Concept
Limit State of Serviceability
Formula
N/A
Step-by-step solution
1. Analyze each statement regarding the Limit State of Serviceability. 2. Note that statement 1 relates to Limit State of Collapse, while statements 2 and 3 correctly describe serviceability checks and safety factors. 3. Select Option (b) as the correct choice.
Explanation
Statement 1 is incorrect because preventing collapse is the purpose of the Limit State of Collapse, not Serviceability. Statements 2 and 3 are correct because the Limit State of Serviceability focuses on controlling deflection and cracking for everyday comfort and durability, using a partial safety factor of 1.0 for working loads under normal service conditions. Therefore, option B (2 and 3 only) is correct.
Shortcut
To remember the concept of Limit State of Serviceability (SLS), use the mnemonic "SERVICE": - Service/Working Loads: Checked under everyday working conditions (Partial safety factor = 1.0). - Everyday Comfort & Durability: Prevents user discomfort, excessive deflection, cracking, and vibration. - Rule out Collapse: Collapse prevention belongs to the Limit State of Collapse, not Serviceability.
Common mistake
A common mistake is selecting option D or option A by confusing the Limit State of Serviceability with the Limit State of Collapse, assuming that preventing structural collapse is a requirement of serviceability. In reality, collapse prevention is covered under the Limit State of Collapse, whereas the Limit State of Serviceability focuses on service conditions such as deflection and cracking. Another frequent mistake is assuming that partial safety factors for loads are always greater than 1.0, forgetting that a factor of 1.0 is standard for serviceability checks.
Correct answer: B) 2 and 3 only