D. Güney. Optimization of The Configuration of Infill Walls in Order To Increase Seismic Resistance of Building Structures
D. Güney. Optimization of The Configuration of Infill Walls in Order To Increase Seismic Resistance of Building Structures
D. Güney. Optimization of The Configuration of Infill Walls in Order To Increase Seismic Resistance of Building Structures
The behavior of empty frames and infilled frames is very different. The infill walls are considered as
non-structural elements and are ignored in the analysis; these elements tend to interact with the frame
in case of lateral load effect. The aim of this paper is to indicate the contribution of infill walls in the
earthquake resistant building design. Three different type of configuration of infill walls are applied in
the numerical models. Consequently, according to the number and position of infill walls in the
numerical analysis the behavior of the structure subjected to the lateral loads is changed.
Key words: Infill walls, seismic, response, optimization, structure, design.
INTRODUCTION
The need for including infill panels in the analysis of RC
frames has been recognized for a long time. The
behavior of empty frames and infilled frames is very
different. The contribution of masonry infills to the global
capacity of the structure constitutes the structural
strength to the 80% and stiffness to the 85%. The main
reason of their beneficial behavior is that the amount of
increase in earthquake inertia force appears to be
relatively small, comparatively with the increase in the
strength of masonry infills (Lee et al., 2002).
Widely used masonry infill elements in the reinforced
concrete frame building design are adobe blocks, hallow
bricks, solid bricks, clay bricks, aerated concrete blocks,
briquette blocks etc.
Although there is no general acceptance of the
contribution of infill walls in the earthquake resistant
design, many researches point out that negative effects
are often associated with irregularities in the distribution
of infills in plan and/or in the evaluation. The main
problem in the design process is mostly that masonry
infills have as-built properties and it is almost impossible
to take into account reliably (Fardis et al., 1999).
Due to the design and methodological complexity
incorporation of infill walls in the numerical analysis as
699
700
0.400
0.300
ag (m/s2)
0.200
0.100
0.000
-0.100
-0.200
-0.300
-0.400
Mu&&(t ) + Cu& (t ) + Ku (t ) = Fe (t )
C = M + K
=
(1)
(2)
i j
i + j
(3)
i +
(4)
701
Column (x.y) (m 2)
Shearwall (x) (m2)
2
Shearwall (y) (m )
2
Infillwall (x) (m )
2
Infillwall (y) (m )
Total area of structuralelements (x) (m2)
Total area of structuralelements (y) (m2)
F/D
G/E
Moment
Without infillwall
6.72
2.80
2.00
0.00
0.00
9.52
8.72
0.00
0.00
CONF. 1
6.72
2.80
2.00
14.10
12.66
9.52
8.72
0.68
1.45
CONF. 2
6.72
2.80
2.00
10.50
8.66
9.52
8.72
0.91
0.99
CONF. 3
6.72
2.80
2.00
10.50
12.66
9.52
8.72
0.91
1.45
CONF. 4
6.72
2.80
2.00
10.50
6.32
9.52
8.72
0.91
0.72
frame
V
Masonry
h h
infill walls
8
l
(a)
(b)
Figure 3. Equivalent strut model for masonry infill walls in frame structures: (a) Masonry infill
frame geometry, (b) Masonry infill walls and strut (Madan and Reinhorn, 1997).
Parameter
Mod.of elasticity E (MPa)
Comp. strength (MPa)
Tensile strength (MPa)
Lowerbound
1500
1.90
1.1
Upperbound
5000
3.2
1.3
702
703
Displacement (m)
0.200
Displacement -u
Conf1
ux
ux-d
t(s)
0.000
10
15
20
25
30
-0.200
Figure 7. Comparison of displacement history in x-direction between two configurations (without and wit infill
walls, Configuration 1).
Displacement (m)
0.100
uy
uy-d
0.050
t (s)
0.000
0
-0.050
10
15
20
25
30
Displacement-u
Conf.1
-0.100
Figure 8. Comparison of displacement history in y-direction between two configurations
(without and with infill walls, Configuration 1).
704
Without infillwall
0.44
0.40
0.31
0.14
0.10
0.170
0.091
0.00
0.00
T1 (s)
T2 (s)
T3 (s)
T4 (s)
T5 (s)
Ux-max (m)
Uy-max (m)
Area rate 1
Area rate 2
CONF. 1
0.36
0.34
0.28
0.12
0.10
0.117
0.072
0.68
1.45
CONF. 2
0.37
0.35
0.29
0.12
0.10
0.122
0.075
0.91
0.99
CONF. 3
0.36
0.35
0.28
0.12
0.10
0.123
0.072
0.91
1.45
CONF. 4
0.36
0.35
0.29
0.12
0.10
0.121
0.082
0.91
0.72
Displacement (m)
0.200
Displacement -u
Conf.2
0.100
ux
ux-d
t(s)
0.000
0
10
15
20
25
30
-0.100
-0.200
Figure 9. Comparison of displacement history in x-direction between two configurations
(without and wit infill walls, Configuration 2).
Displacement (m)
0.100
Displacement - u
Conf.2
0.080
uy
0.060
uy-d
0.040
0.020
t(s)
0.000
-0.020
10
15
20
25
30
-0.040
-0.060
-0.080
-0.100
Displacement (m)
0.200
ux
ux-d
Displacement -u
Conf. 3
0.100
t (s)
0.000
0
10
15
20
25
30
-0.100
-0.200
Figure 11. Comparison of displacement history in x-direction between two configurations
(without and wit infill walls, Configuration 3).
Displacement (m)
0.100
uy
Displacement - u
Conf. 3
uy -d
0.050
t (s)
0.000
0
10
15
20
25
30
-0.050
-0.100
Figure 12. Comparison of displacement history in y-direction between two configurations
(without and with infill walls, Configuration 3).
Displacement (m)
0.200
Displacement
Conf. 4
0.100
ux
-u
ux-d
t (s)
0.000
0
10
15
20
25
30
-0.100
-0.200
Figure 13. Comparison of displacement history in x-direction between two configurations without
and with infill walls, Configuration 4).
705
706