Accounting For Ductility and Overstrength in Seismic Design of Reinforced Concrete Structures
Accounting For Ductility and Overstrength in Seismic Design of Reinforced Concrete Structures
Accounting For Ductility and Overstrength in Seismic Design of Reinforced Concrete Structures
ABSTRACT: This study is conducted to review the methods proposed by seismic codes in order to take account both of the
concept of ductility and overstrength of structural elements. Otherwise, in order to assess how to take account of the
overstrength in reinforced concrete structures, the factors that affect the overstrength and their possible sources are presented,
and reinforced concrete building structures having moment resisting frames or mixed (frames + shear wall), are analyzed for
their responses to lateral loading by applying the static non linear push-over analysis . These structures are assumed located in a
region of high seismicity and are subject to lateral loads deducted from the European seismic code and are designed with the
Algerian codes. The results of this study show the importance of the overstrength that has this type of structures in their ability
to resist horizontal loads caused by earthquakes.
KEY WORDS: Reinforced concrete structure; Overstrenght; Base shear; Ductility; Pushover analysis; Code.
1.
INTRODUCTION
RELATION BETWEEN
DESIGN STRENGHT
OVERSTRENGHT AND
Ductility
factor :
= Ve/Vy
Overstrength
factor :
Rs = Vy/V1
V11
311
C1
C3
C2
C1
B1
C4
C6
C5
C2
C1
B3
B2
B1
3 @ 5.0 m
3 @ 5.0 m
STR1
STR2
B3
C3
B2
C4
3 @ 5.0 m
C2
B1
C1
B3
C6
C5
B2
C4
B1
3 @ 5.0 m
STR3
STR4
Figure 2. Geometry of the structures under investigation.
6.
312
6 @ 3.3 m
B2
C5
C3
6 @ 3.3 m
C2
B3
C6
Wall
C3
Longitudinal
Reinforcement
8-HD20
8-HD16
8-HD14
12-HD20
12-HD16
12-HD14
8-HD20
8-HD20
8-HD20
HD10
R
(RPA)
3.5
2.0
3.5
3.5
q
(EC8)
3.90
3.90
3.12
3.12
Vy
(kN)
1800
3500
1350
1100
V1
(kN)
1000
1500
1000
850
Rs=Vy/V1
1.80
2.33
1.35
1.29
5.0
5.5
4.5
4.0
DISCUSSION OF RESULTS
overstrength.
CONCLUSION
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