Performance-Based Seismic Assessment of Skewed Bridges PEER Transportation Systems Research Program Coordination Meeting at UC-Berkeley, August 25, 2009 An update by Ertugrul Taciroglu, Payman Khalili-Tehrani, UCLA Farzin Zareian, Peyman Kaviani, UCI
55
Embed
Performance-Based Seismic Assessment of Skewed …peer.berkeley.edu/transportation/wp-content/uploads/2011/03/PEER... · Performance-Based Seismic Assessment ... Quantify the Sensitivity
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Performance-Based Seismic Assessment of Skewed Bridges
PEER Transportation Systems Research ProgramCoordination Meeting at UC-Berkeley, August 25, 2009
BYU tests by Rollins et al. (circa 2003) (clean & silty sands, gravel)
Validation
UCDUCLA
BYU
HFD Model
HFD ModelHeight-dependence is explicitly modeled
HFD ModelHeight-dependence is explicitly modeled
Suitable for massive computation
F
yavg
Fult
Fult
2
y
ymax
K
HFD ModelHeight-dependence is explicitly modeled
Suitable for massive computation
Cited in upcoming Caltrans SDC
F
yavg
Fult
Fult
2
y
ymax
K
Shamsabadi A, Khalili-Tehrani P, Stewart JP, Taciroglu E (2009). Validated simulation models for lateral response of bridge abutments with typical backfills, ASCE Journal of Bridge Engineering, (in print).
Recent Work(Caltrans & PEER)
Physically parameterized HFD curves
EHFD EquationF
yavg
Fult
Fult
2
y
ymax
K
F( y) =
C y1+ D y
where
had been shown to be height-independent parameters. ar , br
ar =
1β
(η −1)α br =1β
(η − 2)We decompose them further as in
F( y) =
ar yH + br y
H n
Parametric Studies via LSH
Matrix of soil parameters considered in parametric studies
Linear dependence on γ in agreement with Bell’s equation.
α = slope × γ + imtercept
n-equation for Height Effect on Wall Capacity
7
-equation and its accuracy
η =
15.47 forφ < 5&c ≠ 0
18.10 − 9.38 tan(φ) forφ ≥ 5&c ≠ 0
14.36 − 7.49 tan(φ) for allφ&c = 0
⎧
⎨⎪⎪
⎩⎪⎪
η =
yult
y50
≡ f (φ,c) ≅ f (φ) Affects backbone curve shape, especially at small displacements.
Verification of EHFD Equations
8
Validation against Experimental Data
17
Validation against Experimental Data
17
f = 0.64 (δ/φ) + 0.56
wall friction factor
Validation against Experimental Data
17
f = 0.64 (δ/φ) + 0.56
wall friction factor
Validation against Experimental Data
17
f = 0.64 (δ/φ) + 0.56
wall friction factor
Validation against Experimental Data
17
f = 0.64 (δ/φ) + 0.56
wall friction factor
Validation against Experimental Data
17
f = 0.64 (δ/φ) + 0.56
wall friction factor
Khalili-Tehrani P, Shamsabadi A, Stewart JP, Taciroglu E (2009). Physically parameterized backbone curves for passive resistance of homogeneous backfills, ASCE Journal of Geotechnical & Geoenv. Engineering, (coming soon).
10
Extension toSkew Abutments
UCLA Straight Abutment as Tested
11
45o skew Abutment with UCLA backfill
12
45o skew Abutment with UCLA backfill
12
45o skew Abutment with UCLA backfill
12
45o skew Abutment with UCLA backfill
12
How to scale for skew?
13
straight abutment with wall-width wr
How to scale for skew?
13
straight abutment with wall-width wr
skew abutment with wall-width wr
skew abutment with deck-width wr
How to scale for skew?
13
straight abutment with wall-width wr
skew abutment with wall-width wr
skew abutment with deck-width wr
L
U
R
How to scale for skew?
13
straight abutment with wall-width wr
skew abutment with wall-width wr
skew abutment with deck-width wr
L
U
R
L ! U cos α
How to scale for skew?
13
straight abutment with wall-width wr
skew abutment with wall-width wr
skew abutment with deck-width wr
L
U
R
R = ! L + (1 − !) U
L ! U cos α
How to scale for skew?
13
straight abutment with wall-width wr
skew abutment with wall-width wr
skew abutment with deck-width wr
L
U
R
R = ! L + (1 − !) U
= [! cos " + (1 ! !) ] U
L ! U cos α
How to scale for skew?
13
straight abutment with wall-width wr
skew abutment with wall-width wr
skew abutment with deck-width wr
L
U
R
R = ! L + (1 − !) U
=[
! + (1 ! !) cos−1"
]
L
= [! cos " + (1 ! !) ] U
L ! U cos α
How to scale for skew?
13
skew abutment with wall-width wr
straight abutment with wall-width wr
skew abutment with deck-width wr
L
U
R
R = ! L + (1 − !) U
=[
! + (1 ! !) cos−1"
]
L
= [! cos " + (1 ! !) ] U
! = 0.5
How to scale for skew?
13
skew abutment with wall-width wr
straight abutment with wall-width wr
skew abutment with deck-width wr
L
U
R
R = ! L + (1 − !) U
=[
! + (1 ! !) cos−1"
]
L
= [! cos " + (1 ! !) ] U
! = 0.5
L ! U cos α
quo vadis?
3. Upcoming skew test at UCLA
4. Develop a macroelement for a rotating backwall
5. Incorporate new abutment macroelements into the bridge matrix