Page 217 - Advanced Design Examples of Seismic Retrofit of Structures

210 Advanced Design Examples of Seismic Retrofit of Structures

FIG. 4.10 An example of the infill wall with sold bricks and sand-cement mortar. (Permission
from DRES.)

Field observations of the infill walls indicate that the quality of brick work in the
example building is fair to good; hence, according to ICERIFB [2], the expected
compressive strength of the masonry prism (f me ) and the expected shear strength
of mortar (v me ) are 5.000MPa and 0.165MPa, respectively. The modulus of
elasticity of the masonry prism is:
E me ¼ 550f me ¼ 550 5 ¼ 2750MPa (4.5)
4.4.1.4 Conditions for Activation of Infill Wall Behavior
At this stage, it is assumed that all the frame members can acceptably tolerate
the forces from the infill walls. The acceptance criteria for each frame member
are checked in Section “The Results” and, if vulnerable, proper retrofit solution
is proposed to upgrade these members.
According to ICERIFB [2], each wall should have all of these conditions in
order to be considered as an infill wall:
l The wall shall have adequate strength to when subjected to out-of-plane
force. By assuming the arching action in the walls, the lower-bound out-
of-plane strength of the infill panel is determined using Eq. (4.6).

0:7f mL λ 1 λ 2
Q CL ¼ 144 (4.6)
h inf
t inf
where:
f mL ¼lower bound of masonry compressive strength;
λ 1 ¼slenderness parameter as defined in Table 4.1;