0
1
3
2
4
# of
col
umn
shea
r fai
lure
at
grou
nd s
tory
Sa(T=0.6s ) [g]0.07 0.27 0.5 1.0 1.60
25
0
10
5
15
20
Mea
n re
plac
emen
t cos
t ra
tio (%
)
50% in 50 yrs 10% in 50 yrs 2% in 50 yrs
Earthquake Intensity level
Schematic of infill frame modelTri-linear backbone curve
for infill strut model (Burton & Deierlein 2013)
Stru
t for
ce
ΔrΔy Δcap
Strut deformation
Off-diagonal strut
Diagonal strut
InfillVy
Vcap
A′B′
AB
Diagonal strut
Compression only infill struts
Off-diagonal strut
Rigid end zone offset(PEER/ATC 2010)
Zero-length shear spring (Jeon et al. 2015)
Fiber-section force-based distributed plasticity
beam-column element
Fiber-section force-based distributed plasticity
beam-column element
0.25Vcap
0.75Vcap
0.25Vy
0.75Vy
A B
A′ B′
-60
-40
-20
0
20
40
60
Bas
e sh
ear (
Kip
)
Drift ratio (%)3210-1-2-3
S5Mehrabi (1994)
2Drift ratio (%)
10-1-2-150
-100
-50
0
50
100
150
Bas
e sh
ear (
Kip
)
S7Mehrabi (1994)
(c) Weak frame-solid infill (with column shear failure)
(d) Strong frame-solid infill (without column shear failure)
Specimen 1Sezen (2002)
5Drift ratio (%)
0-5
806040
20
0
-40
-60-80
-20
Col
umn
shea
r (K
ip)
1050-5-10
406080
-80
-60
-40-20
020
10Drift ratio (%)
50-5-10
Col
umn
shea
r (K
ip)
U2Saatcioglu et
al. (1989)
(a) Column flexural failure (b) Column flexural shear failure
FRAGILITY FUNCTIONS FOR A CODE DESIGNED URM INFILLED RC FRAME BUILDING
NSF Funded Project with Collaboration from PEERPrincipal Investigators: Andre R. Barbosa, Michael J. Olsen, OSU, and Andreas Stavridis, UB
Student Investigator: Mohammad Shafiqual Alam,OSUStructural Engineering Research Laboratory, Oregon State University
References:1. Bai, J. W., Hueste, M. B. D., & Gardoni, P. (2009). Probabilistic assessment of structural damage due to earthquakes for buildings in Mid-America. Journal of structural engineering, 135(10), 1155-1163.2. Baker, J. W., & Cornell, C. A. (2006). Vector-valued ground motion intensity measures for probabilistic seismic demand analysis. Pacific Earthquake Engineering Research Center, College of Engineering, University
of California, Berkeley.3. Burton, H., & Deierlein, G. (2013). Simulation of seismic collapse in nonductile reinforced concrete frame buildings with masonry infills. Journal of Structural Engineering, 140(8), A4014016.4. D'Ayala D., & Meslem A. (2013).Sensitivity of analytical fragility functions to capacity-related parameters, GEM Technical. Report 2013-X, GEM Foundation, Pavia.5. FEMA, H. M. M. (2003). Technical Manual, Vol. Earthquake Model. Federal Emergency Management Agency, Washington DC.6. Jeon, J. S., Lowes, L. N., DesRoches, R., & Brilakis, I. (2015). Fragility curves for non-ductile reinforced concrete frames that exhibit different component response mechanisms. Engineering Structures, 85, 127-143.7. Mehrabi, A. B. (1994). Performance of masonry-infilled RC frames under in plane lateral loads (Report CU/SR-94/6). Boulder: University of Colorado.8. Pacific Earthquake Engineering Research Center/Applied Technology Council, (2010). Interim Guidelines on Modeling and Acceptance Criteria for Seismic Design and Analysis of Tall Buildings, PEER/ATC 72-1,
PEER/ATC, Redwood City, California.9. Saneinejad, A., & Hobbs, B. (1995). Inelastic design of infilled frames. Journal of Structural Engineering, 121(4), 634-650.10. Saatcioglu, M., & Ozcebe, G. (1989). Response of reinforced concrete columns to simulated seismic loading. ACI Structural Journal, 86(1).11. Sezen, H. (2002). Seismic behavior and modeling of reinforced concrete building columns, Ph.D. Thesis, Department of Civil and Environmental Engineering, University of California at Berkeley, CA.
1.Motivation
Infilled reinforced concrete buildingperformance data collection in theaftermath of the April 25, 2015 NepalEarthquake (NSF Award #1545632).
Quantitative damage assessments. Need for development of fragility
functions for these types of buildingswas identified.
30 Miles
Epicenter12 May
Epicenter25 April
Mt. Everest
Nuwakot
Charikot
BarabiseChautara
Kathmandu
Bhaktapur
Piskar
Manakamana
Towns and areas visited
5.Fragility, Probabilistic Seismic Demand, and Loss Assessment
The nonlinear structural model is analyzed following MSAapproach using 30 GMs per intensity level for 20 intensitylevels. GMs are selected for a site in Salem, OR having similarseismicity in Dhaka using Conditional spectra.
Fragility curves are developed using generalized linear models. Definition of limit states for RC frame and infilled RC frame
follow approach by D’Ayala and Meslem (2013).
4.Component Validation
capV
3.Modeling Scheme
Infill struts lateral strength, is based on work by Mehrabi etal. (1994).
Initial stiffness is computed using the models by Saneinejadand Hobbs (1995).
2.Case Study Frame
0.03
0
0.02
0.01
Ann
ual r
ate
of e
xcee
danc
e, λ
DS
Damage StateSlight Moderate Extensive Complete
8420 6Sa(T=0.6s ) [g]
P [D
S ≥
ds
|Sa(
T=0.
6s)]
0
0.2
0.4
0.6
0.8
1
Sa(T=0.6s ) [g]40 2 6 8
0.6
0.4
0.2
0
21′ 19′ 12′ 21′ 19′ 12′
12′
12′
12′
15′
15′
15′
12′
12′
12′
15′
15′
15′T=1.0s T=0.6s
Analyzed Infilled RC frame is an internal frame of an existing6-story building of Dhaka Medical College Hospital, Bangladesh.
Designed according to Bangladesh National Building Code(BNBC) which follows International Building Code (2006) andACI 318.
Cases considered in the masonry infill configuration for the RC frames
(a) Bare frame (b) Frame with existing infill
A B F G H I J K LC D E
4
2
1
3
Cla
ss ro
om
Cla
ss ro
om
Cla
ss ro
om
Cla
ss ro
om
Cla
ss ro
om
A B C D E F G H I J
Lecture gallery
1
2
3
4
2nd Floor plan
3rd Floor plan 8420 6Sa(T=0.6s ) [g]
P [D
S ≥
Com
plet
e |S
a(T=
0.6s
)]
0
0.2
0.4
0.6
0.8
1
[]
()
λ≥
dim
IMP
DS
ds|i
m.
dim