Page 215 - Advanced Design Examples of Seismic Retrofit of Structures

208 Advanced Design Examples of Seismic Retrofit of Structures

(A) (B)
FIG. 4.9 Out-of-plane failure of infill walls. (A) Infill walls with three-sided boundary conditions;
look at the crack pattern because of free upper side under lightweight roof; after Avaj earthquake,
2002 (Permission from DRES). (B) Collapse of infill walls due to lack of wall post or other measures
preventing from outward movement; after Ezgeleh earthquake, 2017. (Photo taken by Mohammad
Yekrangnia.)
4.4 EVALUATION OF THE BUILDING
In this part, the example building is evaluated for possible retrofit using criteria
according to ASCE 41 [1] and Iranian Code for Evaluation and Rehabilitation
of Infilled Frame Buildings (ICERIFB) [2]. The main target is to evaluate suffi-
ciency of the existing infill walls in the load-bearing mechanism of the building.

4.4.1 Applicability of the Used Codes
4.4.1.1 Frame
The buildings which can be evaluated according to ICERIFB [2] should have up
to three stories and the frame alone should be adequate for tolerating the load
combinations due to gravity loads, Q G , according to the following actions:
(1) Where the effects or actions of gravity loads and seismic forces are addi-
tive, the action caused by gravity loads, Q G , shall be obtained in accordance
with Eq. (4.2):

Q G ¼ 1:1 Q D + Q L + Q s Þ (4.2)
ð

where:
Q D ¼action caused by dead loads;
Q L ¼action caused by live load, equal to 25% of the unreduced live load
obtained in accordance with ASCE 7 [9] but not less than the actual live
load; and