Page 44 - Advanced Design Examples of Seismic Retrofit of Structures

36 Advanced Design Examples of Seismic Retrofit of Structures

and can easily fall down. In some cases, even partial collapse of nonload-
bearing walls can result in the collapse of the aforesaid bays.
In response to the need for seismic retrofit of these roofs, the Iranian Code of
Practice for Seismic Resistant Design of Buildings (Standard 2800) [7] recom-
mends providing the roof with uniformity by means of placing diagonal steel
strips on the roof. In this way, jack-arch roofs can take advantage of arch action
and maintain their stability during earthquakes. Examples of damage to jack-
arch roofs are shown in Fig. 2.22.

2.4.12 Damage in “Dome Roof”

In some cases, “dome roofs” are not considered as structural parts, and hence
experience different types of damage during earthquakes. There are some case
in which although the building itself performed appropriately, the “dome roof”
experiences severe damage. Fig. 2.23 shows examples of different types of
damage in the “dome roof.” In part (B) of this figure, the collapse of the
“dome roof” on the lower story can easily cause life-threatening damage.

(A) (B)

(C)
FIG. 2.22 Damage in “dome roof”. (A) Partial collapse of “dome roof”. (B) Collapse of “dome
roof” which caused severe damage in the lower story. (C) Out-of-plane failure of wall in “dome
roof” after bam earthquake, 2003. (Permission from DRES.)