If an eight-meter-tall unreinforced masonry building is considered, the approximate collapse zone distance is how many meters?

If an eight-meter-tall unreinforced masonry building is considered, the approximate collapse zone distance is how many meters?

• A. 16 meters
• B. 32 meters
• C. 24 meters
• D. 40 meters

Answer: (C)

The idea behind a collapse zone is to account for how far debris can travel if a building fails. For unreinforced masonry, the potential debris spread is large, so the standard guideline uses a multiplier of the building's height. Specifically, three times the height is used for URM construction. So for an eight-meter-tall URM building, the approximate collapse zone is 8 × 3 = 24 meters. The other multipliers (2×, 4×, 5×) would give distances like 16, 32, or 40 meters, but they aren’t the typical guideline for URM, where 3× height is used.

The idea behind a collapse zone is to account for how far debris can travel if a building fails. For unreinforced masonry, the potential debris spread is large, so the standard guideline uses a multiplier of the building's height. Specifically, three times the height is used for URM construction. So for an eight-meter-tall URM building, the approximate collapse zone is 8 × 3 = 24 meters. The other multipliers (2×, 4×, 5×) would give distances like 16, 32, or 40 meters, but they aren’t the typical guideline for URM, where 3× height is used.