Which of the following statements best describes the Philosophy of Earthquake-Resistant Design as per IS 1893?
- AThe building should remain completely undamaged during a Maximum Considered Earthquake (MCE).
- BThe building should remain functional with no structural damage during a minor earthquake, but may undergo repairable damage during a moderate earthquake and survive without collapse during a major earthquake.Correct
- CEarthquake-proof design is a standard requirement for all residential buildings to ensure zero cracking.
- DThe structure is designed to remain purely elastic even during the strongest possible ground shaking.
Solution
Concept
Philosophy of Earthquake-Resistant Design
Formula
N/A
Step-by-step solution
1. Review the philosophy of earthquake-resistant design as outlined in IS 1893. 2. Recognize that structures should withstand minor earthquakes with no damage, moderate earthquakes with repairable damage, and major earthquakes without collapse. 3. Select Option B as the correct answer.
Explanation
Option B correctly describes the earthquake-resistant design philosophy. It ensures a building suffers no damage during minor earthquakes, incurs only minor or repairable damage during moderate earthquakes, and prevents structural collapse to save lives during strong or major earthquakes.
Shortcut
To remember the IS 1893 Earthquake-Resistant Design Philosophy, use the rule "Minor = Fine, Moderate = Fix, Major = Free from Collapse": - Minor Earthquakes: No structural damage (Fully Functional) - Moderate Earthquakes: Minor or repairable damage (Repairable) - Major Earthquakes: Controlled damage, but strictly NO collapse (Life Safety)
Common mistake
A common mistake is selecting option A or D by incorrectly assuming that earthquake-resistant design aims to make structures completely undamaged or purely elastic during a Maximum Considered Earthquake (MCE). In reality, designing buildings to withstand major shaking without any damage is economically unfeasible, so the IS 1893 design philosophy relies on controlled damage and ductility to dissipate energy and prevent structural collapse.
Correct answer: B) The building should remain functional with no structural damage during a minor earthquake, but may undergo repairable damage during a moderate earthquake and survive without collapse during a major earthquake.