Structural Systems and Building Technology
This domain tests structural load paths, system selection, foundation behavior, and integration with architecture. Expect conceptual questions on span, load, and lateral resistance.
Core rules
- Loads include dead, live, snow, wind, and seismic; load combinations govern design.
- Span-to-depth rules of thumb: steel beam about L/20, concrete beam about L/10 to L/12, wood joist about L/15.
- Lateral systems include shear walls, braced frames, and moment frames; continuity and redundancy matter.
- Foundations include spread footings, mats, and piles; soil bearing and frost depth govern selection.
Worked example
A 30-ft simply supported steel beam with a rule-of-thumb depth of L/20 = 1.5 ft = 18 in. If the architect needs 12 in for ceiling clearance, the beam depth must shrink, increasing deflection; the engineer may need a deeper section, composite action, or a different bay. The architect must coordinate the structural zone before freezing ceiling heights.
Traps
Confusing live load with dead load; ignoring lateral drift; assuming a column can be moved without load-path analysis; using span rules as final design.