Chapter 15

Question 1

3 ways Wood-frame bldg collapse. Correct
A. 90 degree angle wall collapse is sudden and does not give any visible warning signs prior to failure
B. Lean-over collapse usually involves collapse of two, three, or four walls simultaneously
C. 3 story braced frame structure frequently falls in inward/outward collapse. Top 2 stories collapse inward, back on top of pancaked flrs, lower story collapses outward on sidewalk
D. Inward/outward collapse may not exhibit any structural warning at all. Sometimes only indication that a collapse is imminent is a serous fire burning for a long time on an upper fl.

Answer 1

C
A Corners of walls pulling apart from remaining wall
B One side
D Lower fl

Question 2

Wood frame bldg collapse incorrect
A. Bearing wall collapse- flrs will collapse. If interior flrs collapse, bearing walls may collapse
B. In PD, condos, and row-town houses, the front and rear walls ware often load bearing and the two side walls are non-load bearing
C. In peaked roof bldgs, bearing walls support majority of roof rafters that are perpendicular to ridgepole
D. In flat roofed wood bldgs, bearing walls are usually the walls w/shortest dimension and non-load bearing walls have greatest dimension

Answer 2

D Bearing walls have greatest dimension

Question 3

The exterior wall of a wood frame building can be weakened by the weight of a metal fire escape landing or ladder. The metal fire escape transmits what type of load to the exterior wall?
A: Axial
B: Torsional
C: Eccentric
D: None of the above, because it’s a wood frame building

Answer 3

C Without a fire escape, the wood wall studs are under an Axial load….add a metal fire escape now the wall studs are under an eccentric load