Page 475 - Design of Reinforced Masonry Structures

SHEAR WALLS 7.37

Method A: The relative rigidity of the entire wall is taken as the sum of the rela-
tive rigidities of individual piers. Thus,
n
R = ∑ R = 0 714 4 96 4 96 4 96 0 714 16 31. + . + . + . + . = .
i
i=1
The relative rigidity of the perforated shear wall is 16.31.
Method B: Calculate the deflection of the entire wall assuming it as a solid
cantilever.
h 20
= = 025
.
d 80
R = 12.308 (Table A.26)
Calculate the deflection of the solid strip of the wall having length equal to length
of the entire wall and height equal to that of the tallest opening, assuming it as
fixed-ended. It contains piers 2 through 7.
h 10
.
= = 0 125
d 80
R solid strip 2+3+4+5+6+7 = 26.528 (Table A.27)
Calculate the deflection of the solid strip containing piers 3 through 6, assuming
it as fixed-ended.

h 10
.
= = 025 R 3+4+5+6 = 13.061
d 40
∆ ++ + = 1 = 1 = . ( − 2
7 6564 10 )
34 5 6
.
R 34 5 6 13 061
+
++
Calculate the deflections of piers 2 and 7, assuming them as fixed-ended.
R = R = 0.714 (calculated earlier)
2
7
Therefore, ∆ = ∆ = 1 = 1 401
.
7
2
0 714
.
Calculate deflections of piers 3, 4, and 5 individually, assuming them as fixed-

ended.
R = R = R = 4.96 (calculated earlier)
3
5
4
.
Therefore, ∆ = ∆ = ∆ = 1 = 0 2061
5
3
4
496
.
Calculate deflection of Pier 3-4-5.
∆ 34 5 = 1 1 1 1 = 1 1 1 1 = . 0 08628
++
∆ 2 + ∆ 3 4 5 6 + ∆ 7 1 401 + 0 0984 1..401
.
.
+
++