Seismic Simulation and Design of Bridge Columns Under Combined Actions and Implication on

System Response

University of Nevada, Reno

Dr. David H. Sanders Juan Arias-Acosta

Jan. 23 - 2009

Bidirectional Mass Platform (Old idea)

Bidirectional Mass Platform (Old idea)

Bidirectional Mass Platform (New idea)

Bidirectional Mass Platform (Without PD)

Bidirectional Mass Platform (PD system)

Bidirectional Mass Platform (With PD)

Circular Columns (Design Parameters)

Height (in) 72Diameter (in) 16

P (k) 80Cover (in) 0.75

Spiral W5.0Pitch (in) 1.5rl (%) 2.0rs (%) 0.92

   f'c (ksi) 5.5Ec (ksi) 4227fyl (ksi) 65fys (ksi) 60Es (ksi) 29000

   fy 0.00032

My (k-in) 1837fu 0.00473

Mu (k-in) 2136mD 6.56

Vu (k) 29.67Tcr (k-in) 353Tu (k-in) 781

Circular Columns Details (Single Curvature)

Circular Columns Construction

Interlocking Columns Details

Interlocking Columns Construction

Interlocking Spiral Columns (Design Parameters)

Height (in) 72

X Diam (in) 12

YDiam (in) 17.5

P (k) 80

Cover (in) 0.5

Spiral W2.9

Pitch (in) 1

rl (%) 1.97

rs (%) 1.05

   

f'c (ksi) 5.5

Ec (ksi) 4227

fyl (ksi) 65

fys (ksi) 60

Es (ksi) 29000

Dir X Dir Y

fy 0.0004 0.0003

My (k-in) 1402 2026

fu 0.00742 0.00431

Mu (k-in) 1564 2235

mD 7.36 7.36

Vu (k) 22 31

Analytical Model (OpenSees)

Point Mass

Rigid link

Beam with Hinges

Frame Element.

Rigid links

Corotational Truss Ele.

Rigid links

Elastic Beams

Additional mass

Frame Element.

Zerolength Element.

Analytic model (OpenSees)

Mass=80 kipsAxial load with unbonded tendon aprox. 80 KipsTorsional stiffness 0.2JG

Biaxial motionsEl Centro: 0.33, 0.66, 1.0, 1.5, 2.0, 2.5, 3.0Sylmar: 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6 Kobe: 0.3, 0.6, 0.9, 1.2, 1.5, 1.8

Mendocino (Petrolia): 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4Northridge (Sepulveda): 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4

Model 1: Mass frame, without axial load, without PD.Model 2: Mass frame, with unbonded tendon, with PD.

Mass Distribution (Plan view)

Case 1

17 k 17 k

17 k 17 k

Case 2

19.83 k

8.5 k 19.83 k

19.83 k

Case 3

19.83 k8.5 k

19.83 k 19.83 k

Case 4

19.83 k

19.83 k 19.83 k

8.5 k

Case 5

19.83 k

19.83 k 8.5 k

19.83 k

Analysis Results (circular column)

Earthquake Load Top Displ. (in) Base Shear. (in) Base Moments. (k-in) T/Mx T/My

   Case X Y Comp X Y Comp Mx My T    

Mendocino 1 3.16 7.79 8.40 19.79 19.79 34.30 2803.94 1979.28 53.14 0.02 0.03

Petrolia x1.4 2 7.53 7.53 8.13 19.51 19.51 34.08 2795.97 2795.97 489.86 0.18 0.18

  3 7.67 7.67 8.32 20.07 20.07 34.37 2791.71 2005.56 598.19 0.21 0.30

  4 3.11 7.72 8.32 19.70 19.70 34.19 2796.71 1967.59 494.12 0.18 0.25

  5 3.20 7.63 8.27 19.95 19.95 34.27 2788.59 1997.50 600.26 0.22 0.30

                         

Northridge 1 7.90 2.55 8.30 29.44 29.44 36.09 2088.70 2946.93 43.87 0.02 0.01

Sepulveda x1.4 2 7.91 2.53 8.30 29.51 29.51 36.25 2106.56 2953.20 488.79 0.23 0.17

  3 2.55 2.55 8.34 29.51 29.51 36.38 2132.98 2953.75 494.74 0.23 0.17

  4 7.90 2.54 8.30 29.49 29.49 36.21 2102.02 2951.53 422.49 0.20 0.14

  5 7.93 2.52 8.32 29.50 29.50 36.39 2126.79 2952.52 455.94 0.21 0.15

Analysis (Mendocino-Case1)

Test Schedule

Project Name: Seismic Simulation and Design of Bridge Columns Under Combined Actions and Implication on System Response

Principal Investigator: Dr. David Sanders

Assistant Researcher: Juan Arias

CIRCULAR COLUMNS TEST C1 From To

1. Install Mass Rig on table     2/16/2009 2/20/2009

2. Install Column on table     2/23/2009 2/25/2009

3. Initial Instrumentation     2/25/2009 2/27/2009

4. Attach mass to the Mass Rig     3/2/2009 3/3/2009

5. Final Instrumentation     3/4/2009 3/5/2009

6. Check the entire system     3/6/2009 3/6/2009

7. Pre-test       3/9/2009 3/10/2009

8. Test Week       3/10/2009 3/13/2009

9. Post Test- Disassembly     3/16/2009 3/18/2009

10. Data analysis       3/18/2009