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