earthquake simulation and near-fault ground motions effect of ground motion on collapse behavior...

Earthquake Simulation and

Near-Fault Ground Motions

Jack MoehleUC Berkeley

WWW.CONCRETE.ORG/ACI318

WWW.CONCRETE.ORG/ACI318NCREE


Effect of ground motion on collapse behavior

Shin, Galanis, Moehle, EESD 2016


Column detailing

(a) Old details (b) Modern details



Sample results

Typical Modern Column Typical Older Column



Modern Details

Sample results

Chile

Older Details

Kobe



Sample results – Modern columnsHaselton et al (2006) model

0 10 20 30 40 50 60 70-6

-4

-2

0

2

4

6

Time (sec)

Dis

pla

ce

me

nt

(in

)

Top Column Displacement

Analysis

Test 3

-0.15 -0.1 -0.05 0 0.05 0.1 0.15-200

-150

-100

-50

0

50

100

150

200Column 1

Drift / Height

Ba

se

Mo

me

nt

(kip

s-i

n)

-0.15 -0.1 -0.05 0 0.05 0.1 0.15-200

-150

-100

-50

0

50

100

150

200Column 2

Drift / Height

Ba

se

Mo

me

nt

(kip

s-i

n)

0 10 20 30 40-6

-4

-2

0

2

4

6

Time (sec)

Dis

pla

ce

me

nt

(in

)


Analysis

Test 5

-0.15 -0.1 -0.05 0 0.05 0.1 0.15-200

-150

-100

-50

0

50

100

150

200Column 1

Drift / Height

Ba

se

Mo

me

nt

(kip

s-i

n)

-0.15 -0.1 -0.05 0 0.05 0.1 0.15-200

-150

-100

-50

0

50

100

150

200Column 2

Drift / Height

Ba

se

Mo

me

nt

(kip

s-i

n)

Chile Kobe



Sample results – Modern columnsHaselton et al (2006) model

0 10 20 30 40-6

-4

-2

0

2

4

6

Time (sec)

Dis

pla

ce

me

nt

(in

)


Analysis

Test 5

-0.15 -0.1 -0.05 0 0.05 0.1 0.15-200

-150

-100

-50

0

50

100

150

200Column 1

Drift / Height

Ba

se

Mo

me

nt

(kip

s-i

n)

-0.15 -0.1 -0.05 0 0.05 0.1 0.15-200

-150

-100

-50

0

50

100

150

200Column 2

Drift / Height

Ba

se

Mo

me

nt

(kip

s-i

n)

Chile Kobe



Seismic hazard analysis

ARUP


Seismic hazard analysis

Pulse probability for T = 0.75s (0.8g)

Pulse probability for T = 7.5s (0.08g)

ARUP, based on Shahi and Baker (2011)


Seismic hazard

analysis

ARUP


Reinforced

Concrete Frames

with High-Strength

Reinforcement

Under Near-Fault

Ground Motions

To and Moehle, ongoing, Pankow Foundation


Beam (upended)

UC Berkeley

Beam and column tests (Grade 60 to 100)

Column

UT Austin


Test setups

Beam Test Column Test


0

20

40

60

80

100

120

140

160

180

0.00 0.05 0.10 0.15

Stre

ss, k

si

Strain

Gr. 100 T/Y = 1.30

Gr. 100 T/Y = 1.18

Gr. 100 MMFX (A1035)

Gr. 60 T/Y = 1.50 (A615)

Gr. 60 T/Y = 1.36 (A706)

Material properties

Stre

ss, M

Pa

1000

500

0

WWW.CONCRETE.ORG/ACI318Strain profile of longitudinal bars at 4.5% Drift Ratio

Spread of plasticity

No

rmal

ized

po

siti

on

alo

ng

bea

m s

pan

Fixed end

Inflection point


Test results – Column bond failure

Sokoli and Ghannoum, ACI Structural Journal, 2016.

(a) Bond splitting cracks

ℓu

P

MV

M V

P

Cs

Cs

Ts

Ts

(b) Internal forces

Cs Plastic length

Plastic length

Bonded length

Ts

u

(c) Bond forces


Test results – Column bond failure


Test results - Beams

-0.06 -0.04 -0.02 0 0.02 0.04 0.06-80

-60

-40

-20

0

20

40

60

80

Drift Ratio

Late

ral F

orc

e a

t T

ip (

kip

s)

Load vs. Deflection

Initiation of Beam Twisting

-0.06 -0.04 -0.02 0 0.02 0.04 0.06-80

-60

-40

-20

0

20

40

60

80

Drift Ratio

Late

ral F

orc

e a

t T

ip (

kip

s)

Load vs. Drift Ratio

Initiation of Bar Buckling

Start of Beam Twisting

-0.06 -0.04 -0.02 0 0.02 0.04 0.06-80

-60

-40

-20

0

20

40

60

80

Drift Ratio

Late

ral F

orc

e a

t T

ip (

kip

s)


1st Fracture of Longitudinal Bar

2nd Fracture

3rd Fracture

-0.06 -0.04 -0.02 0 0.02 0.04 0.06-80

-60

-40

-20

0

20

40

60

80

Drift Ratio

Late

ral F

orc

e a

t T

ip (

kip

s)


Necking of Longitudinal Bars

Fracture of Longitudinal Bars

Gr. 100 – T/Y = 1.18

Gr. 100 – T/Y = 1.30Gr. 60 A706

Gr. 100 –A1035


Archetype Frame Building (Visnjic 2014)Conventional Grade 60 Reinforcement

Archetype building design


Hypothetical location of archetype buildings from United States

Geological Survey report (marked with bull’s eye)

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0.00 1.00 2.00 3.00 4.00 5.00 6.00

Sa (

g)

Period (s)

DBE MCE

Pseudo-Acceleration Design Spectra

Seismic hazard


0 1 2 3 4 5 60

0.5

1

1.5

2

2.5

3

Period (s)

Sa (

g)

Target MCE Spectrum

Average Near Fault FN-component Spectrum

Scaled Near Fault FN-component Spectra

0 1 2 3 4 5 60

0.5

1

1.5

2

2.5

3

Period (s)

Sa (

g)

Target RotD50 Spectrum

Average Near Fault FP-component Spectrum

Scaled Near Fault FP-component Spectra


Selected and scaled ground motions


Earthquake: Superstition Hills-02,

Station: El Centro Imp. Co. Cent

0 10 20 30 40 50 60 70-60

-40

-20

0

20

40

60

Time Series (s)

Ro

of D

isp

lace

me

nt

Gr. 60 A706

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

-150

-100

-50

0

50

100

150

Strain (in/in)

Str

ess (

ksi)

Gr. 60 A706

Stress-strain response of longitudinal

steel in one of beams

Dynamic analysis results:Roof drift history


0 10 20 30 40 50 60 70-60

-40

-20

0

20

40

60

Time Series (s)

Ro

of D

isp

lace

me

nt

Gr. 60 A706

Gr. 100 T/Y = 1.30

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

-150

-100

-50

0

50

100

150

Strain (in/in)

Str

ess (

ksi)

Gr. 60 A706

Gr. 100 T/Y = 1.30







0 10 20 30 40 50 60 70-60

-40

-20

0

20

40

60

Time Series (s)

Ro

of D

isp

lace

me

nt

Gr. 60 A706

Gr. 100 T/Y = 1.30

Gr. 100 T/Y = 1.18

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

-150

-100

-50

0

50

100

150

Strain (in/in)

Str

ess (

ksi)

Gr. 60 A706

Gr. 100 T/Y = 1.30

Gr. 100 T/Y = 1.18







0 10 20 30 40 50 60 70-60

-40

-20

0

20

40

60

Time Series (s)

Ro

of D

isp

lace

me

nt

Gr. 60 A706

Gr. 100 T/Y = 1.30

Gr. 100 T/Y = 1.18

Gr. 100 A1035

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

-150

-100

-50

0

50

100

150

Strain (in/in)

Str

ess (

ksi)

Gr. 60 A706

Gr. 100 T/Y = 1.30

Gr. 100 T/Y = 1.18

Gr. 100 A1035







Average Displacement


Fault-Normal Components

-50 -40 -30 -20 -10 0 10 20 30 40 500

0.2

0.4

0.6

0.8

1

Displacement (in)

No

rma

lize

d H

eig

ht

Gr. 60 A706

Gr. 100 T/Y = 1.30

Gr. 100 T/Y = 1.18

Gr. 100 A1035

Average Displacement


Fault-Parallel Components

-50 -40 -30 -20 -10 0 10 20 30 40 500

0.2

0.4

0.6

0.8

1

Displacement (in)

No

rma

lize

d H

eig

ht

Gr. 60 A706

Gr. 100 T/Y = 1.30

Gr. 100 T/Y = 1.18

Gr. 100 A1035

Dynamic analysis results:Mean drifts for different reinforcement


Average Drift Ratio


Fault-Normal Components

Average Drift Ratio


Fault-Parallel Components

-0.03 -0.02 -0.01 0 0.01 0.02 0.030

0.2

0.4

0.6

0.8

1

Drift Ratio

No

rma

lize

d H

eig

ht

Gr. 60 A706

Gr. 100 T/Y = 1.30

Gr. 100 T/Y = 1.18

Gr. 100 A1035

-0.03 -0.02 -0.01 0 0.01 0.02 0.030

0.2

0.4

0.6

0.8

1

Drift Ratio

No

rma

lize

d H

eig

ht

Dynamic analysis results:Mean story drift ratios for different reinforcement


Column shears

Τℎ𝑖ℎ𝑛

2 4 6 800.0

0.2

0.4

0.6

0.8

1.0

Nonlinear Dynamic

Τ𝑉𝑖 𝐴𝑔 𝑓𝑐′, psi

0.50

Τ𝑉𝑖 𝐴𝑔 𝑓𝑐′, MPa

d 𝑉𝑢 = 𝜔Ω0𝑉𝑀𝑅𝑆𝐴


ACI 318-19 Code Changes (tentative)

High seismic

• Permit Grade 80 (550)

– T/Y ≥ 1.17

– elongation ≥ 0.10

• Details as shown

– Grade 60

– Grade 80

150 mm6db (5db)d/4

s ≤

Hoopsalong 2hb

100 to 150 mmh/46db (5db)as required for shear

≥ 20db (26db)

≥ 2

.5l d


Earthquake Simulation and


earthquake simulation and near-fault ground motions effect of ground motion on collapse behavior...

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