Post on 31-Mar-2018
Assessment of Capacity of Existing Building Through Nonlinear
Static Pusover Analysis A Comparison between Micro and Macro
Modeling
by
Narender Bodige, Raghavender Baroda, Pradeep Kumar Ramancharla
in
Advances inEarth Sciences, Structural, Geotechnical and Earthquake Engineering(AESG2E-2012)
Report No: IIIT/TR/2012/-1
Centre for Earthquake EngineeringInternational Institute of Information Technology
Hyderabad - 500 032, INDIAOctober 2012
Assessment of Capacity of Existing Building
Through Nonlinear Static Pusover Analysis
A Comparison between Micro and Macro Modeling
B Narender, IIIT Hyderabad
B Raghavender, JNTU Anantapur
and
R Pradeep Kumar
Earthquake Engineering Research Centre
International Institute of Inform
ation Technology
Gachibowli, Hyderabad 500 032, India
Slide 2
EERC @ IIIT, Hyderabad
�Introduction
�Case studies
�Applied Element Method
�Nonlinear Pushover Analysis
�Collapse simulation
�Observations
�Conclusions
OVERVIEW
Slide 3
Reason for collapse of structures
-Earthquake loads
-Wind loads
-Explosions
-Other natural and Manmade disasters
-To understand the process of collapse, we need efficient
numerical model
Slide 4
Collapse during earthquakes
Slide 5
More than 60 % area
is earthquake prone.
Zone V
12 %
Zone IV 18 %
Zone III 26 %
Zone II
44 %
IS 1893:2002
Slide 6
Lat( Deg N )
Long( Deg E )
1819 JUN 16
23.60
68.60
KUTCH,GUJARAT
8.0
1869 JAN 10
25.00
93.00
NEAR CACHAR, ASSAM
7.5
1885 MAY 30
34.10
74.60
SOPOR, J&K
7.0
1897 JUN 12
26.00
91.00
SHILLONGPLATEAU
8.7
1905 APR 04
32.30
76.30
KANGRA, H.P
8.0
1918 JUL 08
24.50
91.00
SRIMANGAL, ASSAM
7.6
1930 JUL 02
25.80
90.20
DHUBRI, ASSAM
7.1
1934JAN 15
26.60
86.80
BIHAR-NEPALBORDER
8.3
1941 JUN 26
12.40
92.50
ANDAMAN ISLANDS
8.1
1943 OCT 23
26.80
94.00
ASSAM
7.2
1950 AUG 15
28.50
96.70
ARUNACHAL PRADESH-CHINA BORDER
8.5
1956 JUL 21
23.30
70.00
ANJAR, GUJARAT
7.0
1967 DEC 10
17.37
73.75
KOYNA, MAHARASHTRA
6.5
1975 JAN 19
32.38
78.49
KINNAUR, HP
6.2
1988 AUG 06
25.13
95.15
MANIPUR-M
YANMAR BORDER
6.6
1988 AUG 21
26.72
86.63
BIHAR-NEPAL BORDER
6.4
1991 OCT 20
30.75
78.86
UTTARKASHI, UP HILLS
6.6
1993 SEP 30
18.07
76.62
LATUR-O
SMANABAD, MAHARASHTRA
6.3
1997 MAY 22
23.08
80.06
JABALPUR,M
P
6.0
1999 M
AR 29
30.41
79.42
CHAMOLI DIST, UP
6.8
2001 JAN 26
23.40
70.32
BHUJ, GUJARAT
6.9
DATE
EPICENTRE
LOCATION
MAGNITUDE
List of Significant Earthquakes in India
and its Neighborhood
Slide 7
PERFORMANCE OF BUILDINGS
Common site destruction in meizoseismalarea
Slide 8
Damage in Anjar
situated on hill
Slide 9
Essentials of
Earthquake Resistant Design
�Configuration
�Strength
�Stiffness
�Ductility
Slide 10
Extensive damage occurred in
non-engineered structures
Many casualties occurred in
stone masonry buildings
Slide 11
Large blocks piled
up using weak bond
Out of plane failure of
brick masonry walls
Slide 12
Soft bottom storey
Slide 13
Pan cake collapse
Surprise for common man:
Adjoining buildings with
radically different
performances
Slide 14
Poor reinforcement
detailing
Slide 15
Weak joint
Slide 16
Numerical technique
Slide 17
Continuum M
odeling
Discrete M
odeling
Numerical Techniques
FEM
RBSM
BEM
Disk Element Method
DDA
EDEM
AEM
Slide 18
APPLIED ELEMENT METHOD
(AEM)
Element Form
ulation
�Material is composed of discrete elements.
�Elements are connected to each other by means of
springs.
Norm
al and S
hear Springs
and shea
r sp
rings
by a
pair o
f norm
al
Are
a repre
sente
d
bd
a
d/2 a
d
b
a
Rein
forc
emen
t bar
Structu
re b
oundary
Slide 19
Spring distribution and area of
influence of each pair of
springs
Element shape, contact point
and degrees of freedom
a
td
EKn
**
=
a
td
GKs
**
=
Slide 20
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
()
α+
α
αα
+θ
+
αα
+θ
αα
+θ
−
αα
+θ
αα
+θ
+
αα
+θ
α+
θ+
α+
θ
α+
θα
+θ
+
α+
θα
+θ
−
αα
+θ
−
αα
+θ
α+
θα
+θ
+
α+
θα
+θ
−
α+
θ+
α+
θ
s2
2
n2
2
sn
ns
sn
n2
s2
sn
ns
sn
s2
n2
KSin
L
KC
os
L
LSin
KSin
LC
os
KC
os
LC
os
KSin
LSin
KC
os
LSin
KSin
LC
os
KC
os
KC
os
KSin
Cos
Sin
K
Cos
Sin
K
LC
os
KSin
LSin
KC
os
Cos
Sin
K
Cos
Sin
K
KC
os
KSin
Slide 21
�Each spring represents area of d*t of cross section and
length "a" i.e. the distance between centrelines.
�Three degrees of freedom, rigid body m
otion.
�Global stiffness m
atrix by adding all the m
atrices.
[]{}
{}F
K=
∆�
Load control & Displacement control.
�Reinforcement is also m
odeled.
Slide 22
�Each spring represents distance (D/2n).
�Horizontal and vertical degrees of freedom have no
effect.
Number of springs
Effect of number of connecting springs on rotational stiffness
Slide 23
Analy
sis dom
ain
of A
EM
com
para
ble
to F
EM
Slide 24
Tension, compression and shear models for concrete
Slide 25
Stress strain relation for steel
Slide 26
cB
a
xa
axσ
σσ
)(
2
−+
=
22
12
1)
2(
)2
(τ
σσ
σσ
σ+
−+
+=
p
)2
()
2ta
n(
21
σσ
τβ
+=
Failure Criteria
Slide 27
Rel
ation b
etw
een load a
nd w
all r
ota
tion for
2-s
tori
ed R
C w
all
0
10
20
30
40
50
60
70
00.0
02
0.0
04
0.0
06
0.0
08
0.0
1
Rota
tion, θ
(rad
)
Load, P (tf)
500 incr
emen
ts
(10 springs)
50 incr
emen
ts
(10 springs)
250 incr
emen
ts
(2 springs)
Exper
imen
t250 incr
emen
ts
(10 springs)
(5 springs)
00.0
02
0.0
04
0.0
06
0.0
08
0.0
1
0
10
20
30
40
50
60
70
50 incr
em
ents
(10 spri
ngs) 500 incr
em
ents
(10 spri
ngs)
Load (x 9.81 kN)
Rota
tion (ra
dia
ns)
Slide 28
Deform
ed shape and crack locations of 2-storied RC wall structure
(in case of 500 increments with 10 springs between each two adjacent faces,
Illustration scale factor=30)
Def
orm
ed shape
and c
rack
ed p
atter
ns
460 k
N540 k
N620 k
N
660 k
N700 k
NE
xper
imen
t
Slide 29
(a)Concrete (b) Steel
Material models for steel and concrete
Slide 30
Dim
ensions and reinforcement of a double cantilever subjected tocyclic loading
Slide 31
-80
-60
-40
-200
20
40
60
80
0500
1000
1500
2000
2500
3000
3500
4000
No. of in
crem
ents
Load (tf)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Load cycles applied to a double cantilever
-60
-40
-200
20
40
60
80
-0.0
15
-0.0
1-0
.005
00.0
05
0.0
10.0
15
0.0
20.0
25
0.0
3
Dis
pla
cem
ent (m
)
Load (tf)
New
model
Exper
imen
t
Load-displacement relation of a double cantilever
Slide 32
Deform
ed shape and crack
patterns of a double cantilever
Slide 33
Finite Element Method (FEM)inSAP-2000
Description of finite element modal at joint
Modeling of a structure
Slide 34
Material model
Kent and park concrete model
IS 456 stress strain curve for steel
Slide 35
Stress blocks at different extreme compression fiber strain
Moment-Curvature
Assumed M-θ
hinge property
Slide 36
Plan of building (All
dimension are in meters)
Elevation of frame along
X-direction
Structural details of Four storey RC building
Column
Beam
C1
360 X 300
C2
C3
C4
360 X 300
360 X 300
360 X 300
B1
300 X 240
B2
300 X 240
B3
300 X 240
B4
300 X 240
Slab thickness: 120
Table.1Schedule of member sizes
Material property of members
Use M20, M25 and M30 grade of
concrete
Fe 250 and Fe 415 for steel
Table.2
material property
Slide 37
S.N
o
Load
Com
bin
atio
nD
LLL
EQ
11.5
DL+1.5
LL
1.5
1.5
-
21.2
(DL+LL
*+EQ
X)
1.2
0.2
5/0
.5*
+1.2
31.2
(DL+LL
*-EQ
X)
1.2
0.2
5/0
.5*
-1.2
41.2
(DL+LL
* +
EQ
Y)
1.2
0.2
5/0
.5*
+1.2
51.2
(DL+LL
* -
EQ
Y)
1.2
0.2
5/0
.5*
-1.2
61.5
(DL+
EQ
X)
1.5
-+1.5
71.5
(DL-EQ
X)
1.5
--1
.5
81.5
(DL+
EQ
Y)
1.5
-1.5
91.5
(DL-EQ
Y)
1.5
--1
.5
10
0.9
DL+1.5
EQ
X0.9
-+1.5
11
0.9
DL-1
.5EQ
X0.9
--1
.5
12
0.9
DL+1.5
EQ
Y0.9
-+1.5
13
0.9
DL-1
.5EQ
Y0.9
--1
.5
Table.3Load combinations for earthquake loading
Loads
Gravity Loads
1. live load : 2 Kn/m
2
2. Floor finishing load: 1 Kn/m
2
3. Brick load : 12.04 Kn/m
Seismic load
1.Zone-II
2.Hard soil
3.Base shear: 26.73 KN
4.Story forces
a.11.25KN at top
b.9.96 KN at Third floor
c. 4.43 KN at second floor
d. 1.11 KN at first floor
Slide 38
EERC @ IIIT, Hyderabad
Load combination of frame along x-direction
Slide 39
3-12mm
8mm@30
0mm c/c
2-8 mm
3-16mm
8mm@30
0mm c/c
2-8 mm
8mm@300
mm c/c
8-20 mm
3-12mm
6mm@10
0 c/c
2-10 mm
4-14mm
6mm@10
0 c/c
2-10 mm
8mm@75
c/c
8-20 mm
IS: 456 design details
IS: 13920 ductile design details
Design details
Slide 40
Steel-Case-1-Column
Steel-Case-2-Column
Non Ductile Ductile
S-M
15, B&C-M
20 S-M
15, B&C-M
20
S-M
15, B-M
20 , C-25 S-M
15, B-M
20, C-25
Non Ductile Ductile
S-M
15, B&C-M
20 S-M
15, B&C-M
20
S-M
15, B-M
20 , C-25 S-M
15, B-M
20, C-25
Structure :
S-M
15, B&C-M
20
S-M
15, B-M
20 & C-M
25
Only Concrete for Beam & Column
Moment-
Curvature
Slide 41
EERC @ IIIT, Hyderabad
Moment Curvature
Moment curvature for M-20 Non-ductile Case-1 Beam
Slide 42
EERC @ IIIT, Hyderabad
Moment curvature for M-20 ductile Case-1 Beam
Slide 43
Moment Curvature
Moment curvature for M-20 Non-ductile Case-1 columns
Slide 44
EERC @ IIIT, Hyderabad
Moment curvature for M-20 Non-ductile Case-2 columns
Slide 45
EERC @ IIIT, Hyderabad
Moment curvature for M-25 Non-ductile Case-1 columns
Slide 46
case-1: Reinforcement details changed in Column-Non
ductile detailing
Pushover curve for 2D RC frame building Non-ductile, S-M
15, B&C-M
20
Comparing Pushover curve from AEM and FEM
Slide 47
case-1: Reinforcement details changed in Column-Non
ductile detailing
Pushover curve for 2D RC frame building Non-ductile, S-M
15, B20 and C-M
25
Slide 48
Case-1: Reinforcement details changed in Column-ductile
detailing
Pushover curve for 2D RC frame building ductile detailing, S-M
15, B & C20
Slide 49
Case-1: Reinforcement details changed in Column-ductile
detailing
Pushover curve for 2D RC frame building Non-ductile, S-M
15, B20 and C-M
25
Slide 50
Case-2: Reinforcement details changed in Column-Non
ductile detailing
Pushover curve for 2D RC frame building Non-ductile, S-M
15, B & C20
Slide 51
Case-2: Reinforcement details changed in Column-ductile
detailing
Pushover curve for 2D RC frame building ductile detailing, S-M
15, B & C20
Slide 52
Pushover curve for four storey concrete structure
Slide 53
Pushover curve for four storey RC Frame for Non-ductile detailing
Slide 54
Pushover curve for four storey RC Frame for Ductile detailing
Slide 55
Pushover curves for Effect of grade of concrete for Non ductiledetailing
Slide 56
Pushover curves for Effect of grade of concrete for ductile detailing
Slide 57
Pushover curves for Change in diameter of bars in column members
non ductile detailing
Slide 58
Pushover Curves change in diameter of bars in column members for
ductile detailing
Slide 59
EERC @ IIIT, Hyderabad
Thank you