Page 356 - Forensic Structural Engineering Handbook

TEMPORARY STRUCTURES IN CONSTRUCTION 10.43

(c)
FIGURE 10.7 Indianapolis Steel Frame.(Continued) (c) Pulled-out and broken column base
anchor bolts. (From Michael A. West, Computerized Structural Design, Milwaukee, WI.)

• The owner and construction manager had responsibility for site safety. They failed to
observe the long anchor bolt projection and the lack of temporary guying of the steel
frame.
Although there were differing and unresolved expert opinions as to the cause of the col-
lapse, it was the structural designer’s belief that the collapse could have been prevented by
the erector’s preparation and implementation of a proper temporary erection bracing and
guying system. This would have resulted in the necessary temporary bracing and guying
materials being on-site as they were needed, and in instructions for their timely installation
and removal as the permanent lateral load-resisting systems were completed (see Fig. 10.7).

Case History 8: Brooklyn Wall Bracing
A 15-ft-high, 93-ft-long, 12-in-thick load-bearing unreinforced-concrete masonry block
wall collapsed during its construction in Brooklyn, New York, on March 23, 1990. The
wall was being built as the south side of a second-floor addition to a one-story commercial
building. The wall toppled away from the mason’s scaffold, fell onto and broke through the
roof of the adjacent one-story building, killing 2 and injuring 14 people below. The mason’s
scaffold was not connected to the wall, so rather grotesquely it remained standing in the
middle of nowhere.
Several improprieties and violations were alleged by OSHA and other investigators soon
after the collapse. These included no building permit, no seal on the architectural/ structural
drawings, no shop drawings for the wall support beams, inadequate and unstable support at
the base of the wall, no inspection, and, perhaps most importantly for construction safety, no
temporary lateral bracing of the wall. Because of the fatalities and the obvious negligence,