Assessment of the Bill Emerson Memorial Bridge - FTP Directory ...

More documents

Recommendations

Info

Measured frequency (Hz)141210864200 2 4 6 8 10 12 14Calculated frequency (Hz)Figure 5.39 Comparison of calculated and measured frequencies5.4.2. Mode shape verificationThe validation of the FE model was evaluated by comparing the graphical representationof the corresponding calculated and identified mode shapes as shown in Figures 5.40 to5.45. It can be visually seen that a good correlation between the calculated and theidentified mode shapes of several vibration modes has been demonstrated. Tosystematically evaluate the correlation of all calculated and identified mode shapes, themodal assurance criterion (MAC) index (Friswell and Mottershead, 1995) is computedfor each mode as follows:th({φ } T )j{φ k} 2MAC jk= (5.6)({φ j} T {φ })({ } Tjφ k{φ k})where { φj} is the j mode shape from the FE model and{φ k}is the k mode shapeidentified from the measured accelerations. In this study, the mode shapes are extractedfrom the seismic records during the May 1, 2005 earthquake. Due to insufficient numberof accelerometers installed on the approach span, only the cable-stayed main span of thebridge is considered. In addition, the exact locations of accelerometers are unknown. Themode shapes identified from the acceleration records are only rough estimates. Thisestimation may cause some uncertainties in the measured mode shapes. The MAC valuesof the bridge are graphically shown in Figure 5.46. It is clearly seen that the calculatedmode shapes correlate rather well with the identified mode shapes. These results furtherensure the reliability of the FE model.th72
10.6TestFE model0.2-0.20 100 200 300 400 500 600 700-0.6Location along the bridge (m)Figure 5.40 Calculated versus measured 1 st mode shape1.20.8TestFE model0.40-0.40 100 200 300 400 500 600 700-0.8-1.2Location along the bridge (m)Figure 5.41 Calculated versus measured 2 nd mode shape73
Page 1 and 2:
Organizational Results Research Rep
Page 3 and 4:
TECHNICAL REPORT DOCUMENTATION PAGE
Page 5 and 6:
Executive SummaryOpen to traffic on
Page 7 and 8:
8. All cables behave elastically un
Page 9 and 10:
Table of ContentsExecutive summary.
Page 11 and 12:
List of Figure CaptionsFigure 1.1 A
Page 13 and 14:
Figure 5.30 29 th mode shape (1.032
Page 15 and 16:
1. Introduction1.1. GeneralCable-st
Page 17 and 18:
Figure 1.1Artist rendering of the B
Page 19 and 20:
Expansionand lateralearthquakerestr
Page 21 and 22:
3. Evaluate the model by conducting
Page 23 and 24:
2. Automatic Retrieval of Peak Acce
Page 25 and 26:
2.2.3. Map/Find stationsClicking th
Page 27 and 28:
2.2.5. Displaying seismogramsTo dis
Page 29 and 30:
Figure 2.8Directory chooser2.2.6. S
Page 31 and 32:
3.2. Seismic instrumentation networ
Page 33 and 34:
The main bridge from Bent 1 to Pier
Page 35 and 36: (a) South side of deck at support o
Page 37 and 38: (a) North side of deck at middle of
Page 39 and 40: The seismic responses at the top (T
Page 41 and 42: Polyreference Complex Exponential (
Page 43 and 44: are evaluated and presented in Figu
Page 45 and 46: 0.353.50.330.252.5Amplitude0.20.15A
Page 47 and 48: 1 x 10-4 Frequency(Hz)Amplitude0.90
Page 49 and 50: Amplitude0.20.180.160.140.120.10.08
Page 51 and 52: Amplitude0.20.180.160.140.120.10.08
Page 53 and 54: 1.20.80.400 100 200 300 400 500 600
Page 55 and 56: 4. Finite Element Modeling of Bill
Page 57 and 58: Since the cable stays are connected
Page 59 and 60: Table 4.3Initial property of cables
Page 61 and 62: Table 4.4Spring and damping coeffic
Page 63 and 64: (a) View of the entire bridge(b) Vi
Page 65 and 66: 4.6. RemarksA detailed 3-D FE model
Page 67 and 68: knω = (5.4)nm nSimilarly, when dam
Page 69 and 70: mainly corresponds to the vertical
Page 71 and 72: thFigure 5.10 9 mode shape (0.740Hz
Page 73 and 74: thFigure 5.19 18 mode shape (0.947H
Page 75 and 76: Figure 5.27 26 th mode shape (0.977
Page 77 and 78: When the bridge deck moves up and d
Page 79 and 80: 1.1Frequency (Hz)0.90.70.5BC Case 1
Page 81 and 82: 1.1Frequency(Hz)0.90.70.5Plus 0Plus
Page 83 and 84: no difference among the three cases
Page 85: The FE model of the bridge was vali
Page 89 and 90: 1.20.80.40-0.4TestFE model0 100 200
Page 91 and 92: differences is that the exact locat
Page 93 and 94: (a) Vertical acceleration time hist
Page 95 and 96: The FE model of the cable-stayed br
Page 97 and 98: Displacement (m)0.30.20.10-0.1-0.2X
Page 99 and 100: Station D1 (before amplification) a
Page 101 and 102: ending of the tower as shown in Fig
Page 103 and 104: symmetric about the centerline of t
Page 105 and 106: Tensile stress (MPa)800750700650600
Page 107 and 108: 7. Conclusions and RecommendationsB
Page 109 and 110: The vast arrays of acceleration dat
Page 111 and 112: 14. Cunha A, Caetano and Delgado T.
Page 113 and 114: 42. Song, W., Giraldo, D.F., Clayto
Page 115 and 116: Figure A.2 Vertical stiffness and d
Page 117 and 118: A.2 Group Interaction FactorThe cro
Page 119 and 120: For a group of piles with identical
Page 121: Missouri Department of Transportati
show all

Assessment of the Bill Emerson Memorial Bridge - FTP Directory ...

Create successful ePaper yourself

Delete template?

Save as template?