The five collapse patterns are generally associated with _____ construction but may be present in all types of construction.

• A. Heavy Wall
• B. Light Frame
• C. Steel Frame
• D. Masonry

Answer: (A)

Understanding how a building is built tells you how it tends to fail. Heavy wall construction relies on thick bearing walls to carry the roof and floor loads. Because those walls form the main load path, when collapse begins the failure tends to propagate along those walls and the connected floor assemblies, producing a set of recognizable shapes. You’ll see patterns such as floors giving way and stacking down in layers (pancake-like failure) or walls yielding and the structure tipping or leaning to one side (lean-to or similar geometries). Those collapse shapes are most strongly linked to heavy-wall systems, since the walls themselves govern how the structure fails. Light-frame or steel-frame buildings distribute loads through framed members, so their common collapse shapes differ accordingly. Masonry is a form of heavy-wall construction, but the term heavy wall is the category the patterns are most closely associated with in this context.