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B-1 A P P E N D I X B Summary of Scour Factors in Tabular and Graphical Form
B-2 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.1 Small BridgeâLow Hydrologic UncertaintyâSmall Pier (1 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 2.40 2.13 1.70 4.10 3.82 4.02 Expected scour () 1.63 1.60 1.55 3.19 3.15 2.99 Bias 0.68 0.75 0.92 0.78 0.82 0.74 Std. dev. () 0.26 0.28 0.41 0.49 0.50 0.71 COV 0.16 0.18 0.26 0.15 0.16 0.24 Design scour 2.96 1.87 0.35 1.87 1.35 1.46 Non exceedance 0.9985 0.9696 0.6356 0.9690 0.9110 0.9281 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 1.76 1.74 1.73 3.41 3.39 3.32 = 1.0 (0.8413) 1.89 1.88 1.96 3.67 3.65 3.69 = 1.5 (0.9332) 2.02 2.03 2.21 3.94 3.93 4.09 = 2.0 (0.9772) 2.15 2.17 2.45 4.22 4.22 4.45 = 2.5 (0.9938) 2.28 2.31 2.70 4.51 4.49 4.81 = 3.0 (0.9987) 2.35 2.39 2.98 4.81 4.84 5.07 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.02 0.83 0.89 0.83 = 1.0 (0.8413) 0.79 0.89 1.16 0.90 0.95 0.92 = 1.5 (0.9332) 0.84 0.95 1.30 0.96 1.03 1.02 = 2.0 (0.9772) 0.90 1.02 1.44 1.03 1.10 1.11 = 2.5 (0.9938) 0.95 1.08 1.59 1.10 1.17 1.20 = 3.0 (0.9987) 0.98 1.13 1.76 1.17 1.27 1.26 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 1.76 1.74 1.76 3.43 3.40 3.34 = 1.0 (0.8413) 1.89 1.88 1.96 3.67 3.65 3.69 = 1.5 (0.9332) 2.02 2.02 2.17 3.92 3.90 4.04 = 2.0 (0.9772) 2.15 2.16 2.37 4.16 4.15 4.40 = 2.5 (0.9938) 2.28 2.30 2.58 4.41 4.40 4.75 = 3.0 (0.9987) 2.41 2.44 2.78 4.65 4.65 5.10 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.04 0.84 0.89 0.83 = 1.0 (0.8413) 0.79 0.88 1.16 0.90 0.95 0.92 = 1.5 (0.9332) 0.84 0.95 1.28 0.96 1.02 1.01 = 2.0 (0.9772) 0.90 1.02 1.40 1.02 1.09 1.09 = 2.5 (0.9938) 0.95 1.08 1.52 1.08 1.15 1.18 = 3.0 (0.9987) 1.00 1.15 1.64 1.14 1.22 1.27
Summary of Scour Factors in Tabular and Graphical Form B-3 Table B.2 Small BridgeâLow Hydrologic UncertaintyâMedium Pier (2 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 4.66 3.78 1.70 6.35 5.47 4.02 Expected scour () 3.16 2.84 1.55 4.72 4.39 2.99 Bias 0.68 0.75 0.92 0.74 0.80 0.74 Std. dev. () 0.51 0.50 0.41 0.67 0.65 0.71 COV 0.16 0.18 0.26 0.14 0.15 0.24 Design scour 2.95 1.87 0.35 2.46 1.66 1.46 Non exceedance 0.9984 0.9696 0.6356 0.9930 0.9517 0.9281 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 3.42 3.08 1.73 5.04 4.71 3.32 = 1.0 (0.8413) 3.68 3.35 1.96 5.38 5.04 3.69 = 1.5 (0.9332) 3.92 3.60 2.21 5.73 5.39 4.09 = 2.0 (0.9772) 4.17 3.84 2.45 6.09 5.75 4.45 = 2.5 (0.9938) 4.44 4.10 2.70 6.46 6.09 4.81 = 3.0 (0.9987) 4.57 4.25 2.98 6.81 6.48 5.07 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.02 0.79 0.86 0.83 = 1.0 (0.8413) 0.79 0.89 1.16 0.85 0.92 0.92 = 1.5 (0.9332) 0.84 0.95 1.30 0.90 0.99 1.02 = 2.0 (0.9772) 0.89 1.02 1.44 0.96 1.05 1.11 = 2.5 (0.9938) 0.95 1.09 1.59 1.02 1.11 1.20 = 3.0 (0.9987) 0.98 1.13 1.76 1.07 1.18 1.26 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 3.42 3.09 1.76 5.05 4.72 3.34 = 1.0 (0.8413) 3.67 3.34 1.96 5.38 5.04 3.69 = 1.5 (0.9332) 3.92 3.59 2.17 5.72 5.37 4.04 = 2.0 (0.9772) 4.17 3.84 2.37 6.05 5.69 4.40 = 2.5 (0.9938) 4.43 4.09 2.58 6.38 6.02 4.75 = 3.0 (0.9987) 4.68 4.34 2.78 6.71 6.35 5.10 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.04 0.79 0.86 0.83 = 1.0 (0.8413) 0.79 0.88 1.16 0.85 0.92 0.92 = 1.5 (0.9332) 0.84 0.95 1.28 0.90 0.98 1.01 = 2.0 (0.9772) 0.90 1.02 1.40 0.95 1.04 1.09 = 2.5 (0.9938) 0.95 1.08 1.52 1.00 1.10 1.18 = 3.0 (0.9987) 1.00 1.15 1.64 1.06 1.16 1.27
B-4 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.3 Small BridgeâLow Hydrologic UncertaintyâLarge Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 6.06 5.17 1.70 7.76 6.87 4.02 Expected scour () 4.12 3.89 1.55 5.67 5.44 2.99 Bias 0.68 0.75 0.92 0.73 0.79 0.74 Std. dev. () 0.66 0.69 0.41 0.79 0.81 0.71 COV 0.16 0.18 0.26 0.14 0.15 0.24 Design scour 2.95 1.87 0.35 2.63 1.77 1.46 Non exceedance 0.9984 0.9695 0.6356 0.9958 0.9619 0.9281 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 4.45 4.22 1.73 6.06 5.83 3.32 = 1.0 (0.8413) 4.79 4.58 1.96 6.47 6.24 3.69 = 1.5 (0.9332) 5.10 4.93 2.21 6.86 6.67 4.09 = 2.0 (0.9772) 5.42 5.27 2.45 7.29 7.09 4.45 = 2.5 (0.9938) 5.77 5.61 2.70 7.70 7.51 4.81 = 3.0 (0.9987) 5.96 5.82 2.98 8.12 7.82 5.07 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.02 0.78 0.85 0.83 = 1.0 (0.8413) 0.79 0.89 1.16 0.83 0.91 0.92 = 1.5 (0.9332) 0.84 0.95 1.30 0.89 0.97 1.02 = 2.0 (0.9772) 0.90 1.02 1.44 0.94 1.03 1.11 = 2.5 (0.9938) 0.95 1.09 1.59 0.99 1.09 1.20 = 3.0 (0.9987) 0.98 1.12 1.76 1.05 1.14 1.26 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 4.45 4.23 1.76 6.07 5.84 3.34 = 1.0 (0.8413) 4.78 4.57 1.96 6.46 6.25 3.69 = 1.5 (0.9332) 5.10 4.92 2.17 6.86 6.65 4.04 = 2.0 (0.9772) 5.43 5.26 2.37 7.26 7.05 4.40 = 2.5 (0.9938) 5.76 5.60 2.58 7.65 7.46 4.75 = 3.0 (0.9987) 6.09 5.95 2.78 8.05 7.86 5.10 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.04 0.78 0.85 0.83 = 1.0 (0.8413) 0.79 0.88 1.16 0.83 0.91 0.92 = 1.5 (0.9332) 0.84 0.95 1.28 0.88 0.97 1.01 = 2.0 (0.9772) 0.90 1.02 1.40 0.94 1.03 1.09 = 2.5 (0.9938) 0.95 1.08 1.52 0.99 1.09 1.18 = 3.0 (0.9987) 1.01 1.15 1.64 1.04 1.14 1.27
Summary of Scour Factors in Tabular and Graphical Form B-5 Table B.4 Small BridgeâMedium Hydrologic UncertaintyâSmall Pier (1 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 2.40 2.13 1.70 4.10 3.82 4.02 Expected scour () 1.63 1.60 1.58 3.21 3.17 2.99 Bias 0.68 0.75 0.93 0.78 0.83 0.74 Std. dev. () 0.26 0.29 0.46 0.53 0.55 0.73 COV 0.16 0.18 0.29 0.17 0.17 0.24 Design scour 2.96 1.84 0.26 1.67 1.18 1.42 Non exceedance 0.9985 0.9674 0.6020 0.9525 0.8819 0.9217 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 1.77 1.74 1.78 3.45 3.42 3.33 = 1.0 (0.8413) 1.90 1.89 2.04 3.74 3.72 3.72 = 1.5 (0.9332) 2.02 2.03 2.32 4.04 4.04 4.10 = 2.0 (0.9772) 2.14 2.18 2.63 4.37 4.35 4.48 = 2.5 (0.9938) 2.26 2.31 2.95 4.68 4.68 4.94 = 3.0 (0.9987) 2.35 2.40 3.29 4.94 5.02 5.34 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.05 0.84 0.90 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 0.91 0.97 0.93 = 1.5 (0.9332) 0.84 0.95 1.37 0.99 1.06 1.02 = 2.0 (0.9772) 0.89 1.02 1.55 1.07 1.14 1.11 = 2.5 (0.9938) 0.94 1.09 1.74 1.14 1.22 1.23 = 3.0 (0.9987) 0.98 1.13 1.94 1.21 1.31 1.33 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 1.76 1.74 1.81 3.47 3.45 3.35 = 1.0 (0.8413) 1.89 1.88 2.04 3.74 3.72 3.72 = 1.5 (0.9332) 2.02 2.03 2.27 4.01 4.00 4.08 = 2.0 (0.9772) 2.15 2.17 2.50 4.27 4.27 4.44 = 2.5 (0.9938) 2.28 2.32 2.74 4.54 4.54 4.81 = 3.0 (0.9987) 2.41 2.46 2.97 4.80 4.82 5.17 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.07 0.85 0.90 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 0.91 0.97 0.92 = 1.5 (0.9332) 0.84 0.95 1.34 0.98 1.05 1.02 = 2.0 (0.9772) 0.90 1.02 1.48 1.04 1.12 1.11 = 2.5 (0.9938) 0.95 1.09 1.61 1.11 1.19 1.20 = 3.0 (0.9987) 1.00 1.16 1.75 1.17 1.26 1.29
B-6 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.5 Small BridgeâMedium Hydrologic UncertaintyâMedium Pier (2 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 4.66 3.78 1.70 6.35 5.47 4.02 Expected scour () 3.16 2.84 1.58 4.74 4.41 2.99 Bias 0.68 0.75 0.93 0.75 0.81 0.74 Std. dev. () 0.51 0.51 0.46 0.71 0.70 0.73 COV 0.16 0.18 0.29 0.15 0.16 0.24 Design scour 2.95 1.84 0.26 2.27 1.52 1.42 Non exceedance 0.9984 0.9673 0.6020 0.9884 0.9352 0.9217 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 3.42 3.10 1.78 5.08 4.75 3.33 = 1.0 (0.8413) 3.68 3.35 2.04 5.45 5.12 3.72 = 1.5 (0.9332) 3.93 3.61 2.32 5.84 5.50 4.10 = 2.0 (0.9772) 4.16 3.87 2.63 6.22 5.87 4.48 = 2.5 (0.9938) 4.37 4.11 2.95 6.58 6.22 4.94 = 3.0 (0.9987) 4.57 4.27 3.29 6.91 6.65 5.34 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.05 0.80 0.87 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 0.86 0.93 0.93 = 1.5 (0.9332) 0.84 0.95 1.37 0.92 1.01 1.02 = 2.0 (0.9772) 0.89 1.02 1.55 0.98 1.07 1.11 = 2.5 (0.9938) 0.94 1.09 1.74 1.04 1.14 1.23 = 3.0 (0.9987) 0.98 1.13 1.94 1.09 1.21 1.33 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 3.42 3.09 1.81 5.09 4.76 3.35 = 1.0 (0.8413) 3.67 3.35 2.04 5.45 5.11 3.72 = 1.5 (0.9332) 3.92 3.60 2.27 5.80 5.46 4.08 = 2.0 (0.9772) 4.18 3.86 2.50 6.16 5.81 4.44 = 2.5 (0.9938) 4.43 4.11 2.74 6.52 6.16 4.81 = 3.0 (0.9987) 4.68 4.37 2.97 6.87 6.51 5.17 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.07 0.80 0.87 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 0.86 0.93 0.92 = 1.5 (0.9332) 0.84 0.95 1.34 0.91 1.00 1.02 = 2.0 (0.9772) 0.90 1.02 1.48 0.97 1.06 1.11 = 2.5 (0.9938) 0.95 1.09 1.61 1.03 1.13 1.20 = 3.0 (0.9987) 1.01 1.16 1.75 1.08 1.19 1.29
Summary of Scour Factors in Tabular and Graphical Form B-7 Table B.6 Small BridgeâMedium Hydrologic UncertaintyâLarge Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 6.06 5.17 1.70 7.76 6.87 4.02 Expected scour () 4.12 3.88 1.58 5.70 5.46 2.99 Bias 0.68 0.75 0.93 0.73 0.79 0.74 Std. dev. () 0.66 0.70 0.46 0.84 0.86 0.73 COV 0.16 0.18 0.29 0.15 0.16 0.24 Design scour 2.94 1.84 0.26 2.47 1.65 1.42 Non exceedance 0.9983 0.9672 0.6020 0.9932 0.9500 0.9217 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 4.46 4.24 1.78 6.10 5.88 3.33 = 1.0 (0.8413) 4.79 4.59 2.04 6.53 6.32 3.72 = 1.5 (0.9332) 5.12 4.94 2.32 6.98 6.77 4.10 = 2.0 (0.9772) 5.42 5.31 2.63 7.42 7.19 4.48 = 2.5 (0.9938) 5.70 5.62 2.95 7.84 7.68 4.94 = 3.0 (0.9987) 5.96 5.84 3.29 8.28 8.09 5.34 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.05 0.79 0.86 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 0.84 0.92 0.93 = 1.5 (0.9332) 0.85 0.95 1.37 0.90 0.99 1.02 = 2.0 (0.9772) 0.89 1.03 1.55 0.96 1.05 1.11 = 2.5 (0.9938) 0.94 1.09 1.74 1.01 1.12 1.23 = 3.0 (0.9987) 0.98 1.13 1.94 1.07 1.18 1.33 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 4.45 4.23 1.81 6.11 5.89 3.35 = 1.0 (0.8413) 4.78 4.58 2.04 6.53 6.32 3.72 = 1.5 (0.9332) 5.11 4.93 2.27 6.95 6.74 4.08 = 2.0 (0.9772) 5.44 5.28 2.50 7.37 7.17 4.44 = 2.5 (0.9938) 5.77 5.63 2.74 7.79 7.60 4.81 = 3.0 (0.9987) 6.10 5.98 2.97 8.20 8.03 5.17 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.07 0.79 0.86 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 0.84 0.92 0.92 = 1.5 (0.9332) 0.84 0.95 1.34 0.90 0.98 1.02 = 2.0 (0.9772) 0.90 1.02 1.48 0.95 1.04 1.11 = 2.5 (0.9938) 0.95 1.09 1.61 1.00 1.11 1.20 = 3.0 (0.9987) 1.01 1.16 1.75 1.06 1.17 1.29
B-8 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.7 Small BridgeâHigh Hydrologic UncertaintyâSmall Pier (1 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 2.40 2.13 1.70 4.10 3.82 4.02 Expected scour () 1.63 1.60 1.58 3.21 3.18 3.01 Bias 0.68 0.75 0.93 0.78 0.83 0.75 Std. dev. () 0.26 0.28 0.55 0.61 0.63 0.78 COV 0.16 0.18 0.35 0.19 0.20 0.26 Design scour 2.99 1.87 0.20 1.45 1.03 1.29 Non exceedance 0.9986 0.9690 0.5806 0.9259 0.8481 0.9013 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 1.76 1.74 1.80 3.47 3.44 3.37 = 1.0 (0.8413) 1.89 1.88 2.12 3.81 3.80 3.78 = 1.5 (0.9332) 2.02 2.03 2.47 4.20 4.17 4.23 = 2.0 (0.9772) 2.14 2.16 2.89 4.57 4.58 4.71 = 2.5 (0.9938) 2.26 2.30 3.30 5.04 5.05 5.15 = 3.0 (0.9987) 2.35 2.41 3.82 5.53 5.56 5.69 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.06 0.85 0.90 0.84 = 1.0 (0.8413) 0.79 0.89 1.25 0.93 0.99 0.94 = 1.5 (0.9332) 0.84 0.96 1.46 1.02 1.09 1.05 = 2.0 (0.9772) 0.89 1.02 1.70 1.11 1.20 1.17 = 2.5 (0.9938) 0.94 1.08 1.95 1.23 1.32 1.28 = 3.0 (0.9987) 0.98 1.13 2.25 1.35 1.45 1.42 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 1.76 1.74 1.86 3.52 3.49 3.40 = 1.0 (0.8413) 1.89 1.88 2.13 3.82 3.81 3.79 = 1.5 (0.9332) 2.02 2.02 2.41 4.13 4.12 4.18 = 2.0 (0.9772) 2.15 2.16 2.68 4.43 4.43 4.57 = 2.5 (0.9938) 2.27 2.31 2.96 4.74 4.74 4.96 = 3.0 (0.9987) 2.40 2.45 3.24 5.04 5.06 5.35 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.10 0.86 0.91 0.85 = 1.0 (0.8413) 0.79 0.88 1.26 0.93 1.00 0.94 = 1.5 (0.9332) 0.84 0.95 1.42 1.01 1.08 1.04 = 2.0 (0.9772) 0.89 1.02 1.58 1.08 1.16 1.14 = 2.5 (0.9938) 0.95 1.08 1.75 1.16 1.24 1.24 = 3.0 (0.9987) 1.00 1.15 1.91 1.23 1.32 1.33
Summary of Scour Factors in Tabular and Graphical Form B-9 Table B.8 Small BridgeâHigh Hydrologic UncertaintyâMedium Pier (2 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 4.66 3.78 1.70 6.35 5.47 4.02 Expected scour () 3.16 2.83 1.58 4.74 4.42 3.01 Bias 0.68 0.75 0.93 0.75 0.81 0.75 Std. dev. () 0.51 0.51 0.55 0.79 0.77 0.78 COV 0.16 0.18 0.35 0.17 0.17 0.26 Design scour 2.97 1.86 0.20 2.05 1.38 1.29 Non exceedance 0.9985 0.9688 0.5806 0.9797 0.9154 0.9013 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 3.41 3.09 1.80 5.10 4.77 3.37 = 1.0 (0.8413) 3.67 3.35 2.12 5.52 5.17 3.78 = 1.5 (0.9332) 3.93 3.61 2.47 5.98 5.62 4.23 = 2.0 (0.9772) 4.17 3.86 2.89 6.41 6.07 4.71 = 2.5 (0.9938) 4.40 4.09 3.30 6.94 6.53 5.15 = 3.0 (0.9987) 4.61 4.27 3.82 7.49 7.15 5.69 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.06 0.80 0.87 0.84 = 1.0 (0.8413) 0.79 0.89 1.25 0.87 0.95 0.94 = 1.5 (0.9332) 0.84 0.96 1.46 0.94 1.03 1.05 = 2.0 (0.9772) 0.90 1.02 1.70 1.01 1.11 1.17 = 2.5 (0.9938) 0.95 1.08 1.95 1.09 1.19 1.28 = 3.0 (0.9987) 0.99 1.13 2.25 1.18 1.31 1.42 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 3.41 3.09 1.86 5.13 4.80 3.40 = 1.0 (0.8413) 3.66 3.34 2.13 5.53 5.19 3.79 = 1.5 (0.9332) 3.91 3.59 2.41 5.92 5.57 4.18 = 2.0 (0.9772) 4.17 3.85 2.68 6.32 5.95 4.57 = 2.5 (0.9938) 4.42 4.10 2.96 6.71 6.34 4.96 = 3.0 (0.9987) 4.67 4.35 3.24 7.10 6.72 5.35 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.10 0.81 0.88 0.85 = 1.0 (0.8413) 0.79 0.88 1.26 0.87 0.95 0.94 = 1.5 (0.9332) 0.84 0.95 1.42 0.93 1.02 1.04 = 2.0 (0.9772) 0.89 1.02 1.58 0.99 1.09 1.14 = 2.5 (0.9938) 0.95 1.09 1.75 1.06 1.16 1.24 = 3.0 (0.9987) 1.00 1.15 1.91 1.12 1.23 1.33
B-10 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.9 Small BridgeâHigh Hydrologic UncertaintyâLarge Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 6.06 5.17 1.70 7.76 6.87 4.02 Expected scour () 4.12 3.88 1.58 5.70 5.46 3.01 Bias 0.68 0.75 0.93 0.73 0.80 0.75 Std. dev. () 0.66 0.70 0.55 0.91 0.92 0.78 COV 0.16 0.18 0.35 0.16 0.17 0.26 Design scour 2.94 1.86 0.20 2.25 1.53 1.29 Non exceedance 0.9983 0.9684 0.5806 0.9878 0.9369 0.9013 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 4.45 4.23 1.80 6.12 5.90 3.37 = 1.0 (0.8413) 4.78 4.58 2.12 6.61 6.38 3.78 = 1.5 (0.9332) 5.13 4.94 2.47 7.12 6.88 4.23 = 2.0 (0.9772) 5.44 5.29 2.89 7.64 7.38 4.71 = 2.5 (0.9938) 5.76 5.61 3.30 8.24 7.93 5.15 = 3.0 (0.9987) 6.02 5.85 3.82 8.85 8.55 5.69 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.06 0.79 0.86 0.84 = 1.0 (0.8413) 0.79 0.89 1.25 0.85 0.93 0.94 = 1.5 (0.9332) 0.85 0.96 1.46 0.92 1.00 1.05 = 2.0 (0.9772) 0.90 1.02 1.70 0.98 1.07 1.17 = 2.5 (0.9938) 0.95 1.09 1.95 1.06 1.15 1.28 = 3.0 (0.9987) 0.99 1.13 2.25 1.14 1.24 1.42 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 4.45 4.23 1.86 6.16 5.92 3.40 = 1.0 (0.8413) 4.78 4.58 2.13 6.61 6.38 3.79 = 1.5 (0.9332) 5.11 4.92 2.41 7.07 6.84 4.18 = 2.0 (0.9772) 5.44 5.27 2.68 7.53 7.30 4.57 = 2.5 (0.9938) 5.77 5.62 2.96 7.98 7.76 4.96 = 3.0 (0.9987) 6.10 5.97 3.24 8.44 8.22 5.35 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.10 0.79 0.86 0.85 = 1.0 (0.8413) 0.79 0.88 1.26 0.85 0.93 0.94 = 1.5 (0.9332) 0.84 0.95 1.42 0.91 1.00 1.04 = 2.0 (0.9772) 0.90 1.02 1.58 0.97 1.06 1.14 = 2.5 (0.9938) 0.95 1.09 1.75 1.03 1.13 1.24 = 3.0 (0.9987) 1.01 1.15 1.91 1.09 1.20 1.33
Summary of Scour Factors in Tabular and Graphical Form B-11 Table B.10 Medium BridgeâLow Hydrologic UncertaintyâSmall Pier (1.5 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 3.60 3.19 8.02 11.62 11.21 15.12 Expected scour () 2.45 2.39 7.36 9.81 9.75 11.23 Bias 0.68 0.75 0.92 0.84 0.87 0.74 Std. dev. () 0.39 0.43 2.21 2.25 2.26 2.88 COV 0.16 0.18 0.30 0.23 0.23 0.26 Design scour 2.95 1.85 0.30 0.81 0.65 1.35 Non exceedance 0.9984 0.9676 0.6170 0.7897 0.7406 0.9113 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 2.65 2.61 8.34 10.80 10.78 12.58 = 1.0 (0.8413) 2.84 2.84 9.59 12.10 12.01 14.09 = 1.5 (0.9332) 3.04 3.04 10.84 13.31 13.28 15.66 = 2.0 (0.9772) 3.23 3.26 12.30 14.75 14.76 17.31 = 2.5 (0.9938) 3.43 3.46 13.65 16.17 16.15 19.27 = 3.0 (0.9987) 3.54 3.61 15.15 17.50 17.65 20.87 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.04 0.93 0.96 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 1.04 1.07 0.93 = 1.5 (0.9332) 0.85 0.95 1.35 1.15 1.18 1.04 = 2.0 (0.9772) 0.90 1.02 1.53 1.27 1.32 1.15 = 2.5 (0.9938) 0.95 1.08 1.70 1.39 1.44 1.27 = 3.0 (0.9987) 0.98 1.13 1.89 1.51 1.57 1.38 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 2.64 2.61 8.46 10.93 10.88 12.67 = 1.0 (0.8413) 2.84 2.83 9.57 12.05 12.01 14.11 = 1.5 (0.9332) 3.04 3.04 10.68 13.18 13.14 15.55 = 2.0 (0.9772) 3.23 3.26 11.78 14.30 14.27 17.00 = 2.5 (0.9938) 3.43 3.47 12.89 15.42 15.40 18.44 = 3.0 (0.9987) 3.62 3.69 14.00 16.55 16.52 19.88 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.06 0.94 0.97 0.84 = 1.0 (0.8413) 0.79 0.89 1.19 1.04 1.07 0.93 = 1.5 (0.9332) 0.84 0.95 1.33 1.13 1.17 1.03 = 2.0 (0.9772) 0.90 1.02 1.47 1.23 1.27 1.12 = 2.5 (0.9938) 0.95 1.09 1.61 1.33 1.37 1.22 = 3.0 (0.9987) 1.01 1.16 1.75 1.42 1.47 1.32
B-12 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.11 Medium BridgeâLow Hydrologic UncertaintyâMedium Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 7.20 5.94 8.02 15.22 13.95 15.12 Expected scour () 4.90 4.45 7.36 12.26 11.81 11.23 Bias 0.68 0.75 0.92 0.81 0.85 0.74 Std. dev. () 0.78 0.81 2.21 2.34 2.37 2.88 COV 0.16 0.18 0.30 0.19 0.20 0.26 Design scour 2.95 1.84 0.30 1.26 0.90 1.35 Non exceedance 0.9984 0.9672 0.6170 0.8967 0.8168 0.9113 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 5.29 4.87 8.34 13.31 12.90 12.58 = 1.0 (0.8413) 5.68 5.27 9.59 14.62 14.20 14.09 = 1.5 (0.9332) 6.09 5.66 10.84 15.94 15.50 15.66 = 2.0 (0.9772) 6.46 6.06 12.30 17.42 17.02 17.31 = 2.5 (0.9938) 6.86 6.45 13.65 18.80 18.47 19.27 = 3.0 (0.9987) 7.08 6.71 15.15 20.33 20.18 20.87 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.04 0.87 0.92 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 0.96 1.02 0.93 = 1.5 (0.9332) 0.85 0.95 1.35 1.05 1.11 1.04 = 2.0 (0.9772) 0.90 1.02 1.53 1.14 1.22 1.15 = 2.5 (0.9938) 0.95 1.09 1.70 1.24 1.32 1.27 = 3.0 (0.9987) 0.98 1.13 1.89 1.34 1.45 1.38 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 5.29 4.86 8.46 13.43 12.99 12.67 = 1.0 (0.8413) 5.68 5.26 9.57 14.60 14.18 14.11 = 1.5 (0.9332) 6.07 5.66 10.68 15.77 15.37 15.55 = 2.0 (0.9772) 6.46 6.06 11.78 16.94 16.55 17.00 = 2.5 (0.9938) 6.85 6.47 12.89 18.12 17.74 18.44 = 3.0 (0.9987) 7.24 6.87 14.00 19.29 18.93 19.88 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.06 0.88 0.93 0.84 = 1.0 (0.8413) 0.79 0.89 1.19 0.96 1.02 0.93 = 1.5 (0.9332) 0.84 0.95 1.33 1.04 1.10 1.03 = 2.0 (0.9772) 0.90 1.02 1.47 1.11 1.19 1.12 = 2.5 (0.9938) 0.95 1.09 1.61 1.19 1.27 1.22 = 3.0 (0.9987) 1.01 1.16 1.75 1.27 1.36 1.32
Summary of Scour Factors in Tabular and Graphical Form B-13 Table B.12 Medium BridgeâLow Hydrologic UncertaintyâLarge Pier (4.5 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 10.35 8.44 8.02 18.37 16.45 15.12 Expected scour () 7.06 6.33 7.36 14.41 13.69 11.23 Bias 0.68 0.75 0.92 0.78 0.83 0.74 Std. dev. () 1.14 1.15 2.21 2.57 2.53 2.88 COV 0.16 0.18 0.30 0.18 0.18 0.26 Design scour 2.89 1.84 0.30 1.54 1.09 1.35 Non exceedance 0.9981 0.9670 0.6170 0.9380 0.8632 0.9113 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 7.62 6.92 8.34 15.59 14.87 12.58 = 1.0 (0.8413) 8.21 7.49 9.59 17.00 16.22 14.09 = 1.5 (0.9332) 8.80 8.05 10.84 18.40 17.59 15.66 = 2.0 (0.9772) 9.34 8.63 12.30 20.05 19.15 17.31 = 2.5 (0.9938) 9.90 9.14 13.65 21.50 20.70 19.27 = 3.0 (0.9987) 10.33 9.55 15.15 23.11 22.34 20.87 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.04 0.85 0.90 0.83 = 1.0 (0.8413) 0.79 0.89 1.20 0.93 0.99 0.93 = 1.5 (0.9332) 0.85 0.95 1.35 1.00 1.07 1.04 = 2.0 (0.9772) 0.90 1.02 1.53 1.09 1.16 1.15 = 2.5 (0.9938) 0.96 1.08 1.70 1.17 1.26 1.27 = 3.0 (0.9987) 1.00 1.13 1.89 1.26 1.36 1.38 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 7.63 6.90 8.46 15.70 14.95 12.67 = 1.0 (0.8413) 8.20 7.48 9.57 16.98 16.21 14.11 = 1.5 (0.9332) 8.77 8.05 10.68 18.27 17.48 15.55 = 2.0 (0.9772) 9.34 8.62 11.78 19.56 18.74 17.00 = 2.5 (0.9938) 9.91 9.20 12.89 20.84 20.00 18.44 = 3.0 (0.9987) 10.48 9.77 14.00 22.13 21.27 19.88 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.74 0.82 1.06 0.85 0.91 0.84 = 1.0 (0.8413) 0.79 0.89 1.19 0.92 0.99 0.93 = 1.5 (0.9332) 0.85 0.95 1.33 0.99 1.06 1.03 = 2.0 (0.9772) 0.90 1.02 1.47 1.06 1.14 1.12 = 2.5 (0.9938) 0.96 1.09 1.61 1.13 1.22 1.22 = 3.0 (0.9987) 1.01 1.16 1.75 1.20 1.29 1.32
B-14 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.13 Medium BridgeâMedium Hydrologic UncertaintyâSmall Pier (1.5 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂo n Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 3.60 3.19 8.02 11.62 11.21 15.12 Expected scour () 2.45 2.39 7.42 9.87 9.81 11.35 Bias 0.68 0.75 0.93 0.85 0.88 0.75 Std. dev. () 0.39 0.42 2.74 2.78 2.78 3.18 COV 0.16 0.18 0.37 0.28 0.28 0.28 Design scour 2.99 1.90 0.22 0.63 0.50 1.18 Non exceedance 0.9986 0.9713 0.5857 0.7353 0.6923 0.8818 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 2.64 2.60 8.60 11.07 11.02 12.77 = 1.0 (0.8413) 2.84 2.82 10.17 12.66 12.61 14.55 = 1.5 (0.9332) 3.03 3.03 11.89 14.36 14.31 16.38 = 2.0 (0.9772) 3.22 3.23 13.56 16.08 16.04 18.21 = 2.5 (0.9938) 3.37 3.41 15.50 18.02 17.89 20.54 = 3.0 (0.9987) 3.48 3.56 17.24 19.79 19.79 22.31 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.07 0.95 0.98 0.84 = 1.0 (0.8413) 0.79 0.88 1.27 1.09 1.13 0.96 = 1.5 (0.9332) 0.84 0.95 1.48 1.24 1.28 1.08 = 2.0 (0.9772) 0.89 1.01 1.69 1.38 1.43 1.20 = 2.5 (0.9938) 0.94 1.07 1.93 1.55 1.60 1.36 = 3.0 (0.9987) 0.97 1.12 2.15 1.70 1.77 1.48 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 2.64 2.60 8.79 11.26 11.20 12.94 = 1.0 (0.8413) 2.83 2.81 10.16 12.65 12.59 14.53 = 1.5 (0.9332) 3.02 3.02 11.53 14.03 13.98 16.12 = 2.0 (0.9772) 3.22 3.23 12.91 15.42 15.37 17.72 = 2.5 (0.9938) 3.41 3.45 14.28 16.81 16.76 19.31 = 3.0 (0.9987) 3.60 3.66 15.65 18.20 18.15 20.90 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.81 1.10 0.97 1.00 0.86 = 1.0 (0.8413) 0.79 0.88 1.27 1.09 1.12 0.96 = 1.5 (0.9332) 0.84 0.95 1.44 1.21 1.25 1.07 = 2.0 (0.9772) 0.89 1.01 1.61 1.33 1.37 1.17 = 2.5 (0.9938) 0.95 1.08 1.78 1.45 1.50 1.28 = 3.0 (0.9987) 1.00 1.15 1.95 1.57 1.62 1.38
Summary of Scour Factors in Tabular and Graphical Form B-15 Table B.14 Medium BridgeâMedium Hydrologic UncertaintyâMedium Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 7.20 5.94 8.02 15.22 13.95 15.12 Expected scour () 4.89 4.45 7.42 12.31 11.87 11.35 Bias 0.68 0.75 0.93 0.81 0.85 0.75 Std. dev. () 0.77 0.79 2.74 2.86 2.89 3.18 COV 0.16 0.18 0.37 0.23 0.24 0.28 Design scour 2.99 1.89 0.22 1.01 0.72 1.18 Non exceedance 0.9986 0.9706 0.5857 0.8444 0.7648 0.8818 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 5.29 4.85 8.60 13.58 13.13 12.77 = 1.0 (0.8413) 5.68 5.24 10.17 15.18 14.76 14.55 = 1.5 (0.9332) 6.05 5.63 11.89 16.90 16.47 16.38 = 2.0 (0.9772) 6.44 6.01 13.56 18.69 18.28 18.21 = 2.5 (0.9938) 6.73 6.37 15.50 20.73 20.21 20.54 = 3.0 (0.9987) 6.96 6.62 17.24 22.54 22.19 22.31 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.07 0.89 0.94 0.84 = 1.0 (0.8413) 0.79 0.88 1.27 1.00 1.06 0.96 = 1.5 (0.9332) 0.84 0.95 1.48 1.11 1.18 1.08 = 2.0 (0.9772) 0.89 1.01 1.69 1.23 1.31 1.20 = 2.5 (0.9938) 0.94 1.07 1.93 1.36 1.45 1.36 = 3.0 (0.9987) 0.97 1.11 2.15 1.48 1.59 1.48 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 5.28 4.84 8.79 13.75 13.31 12.94 = 1.0 (0.8413) 5.66 5.23 10.16 15.18 14.75 14.53 = 1.5 (0.9332) 6.05 5.63 11.53 16.61 16.20 16.12 = 2.0 (0.9772) 6.43 6.02 12.91 18.04 17.64 17.72 = 2.5 (0.9938) 6.82 6.42 14.28 19.48 19.08 19.31 = 3.0 (0.9987) 7.20 6.81 15.65 20.91 20.53 20.90 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.10 0.90 0.95 0.86 = 1.0 (0.8413) 0.79 0.88 1.27 1.00 1.06 0.96 = 1.5 (0.9332) 0.84 0.95 1.44 1.09 1.16 1.07 = 2.0 (0.9772) 0.89 1.01 1.61 1.19 1.26 1.17 = 2.5 (0.9938) 0.95 1.08 1.78 1.28 1.37 1.28 = 3.0 (0.9987) 1.00 1.15 1.95 1.37 1.47 1.38
B-16 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.15 Medium BridgeâMedium Hydrologic UncertaintyâLarge Pier (4.5 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 10.35 8.44 8.02 18.37 16.45 15.12 Expected scour () 7.05 6.32 7.42 14.47 13.74 11.35 Bias 0.68 0.75 0.93 0.79 0.84 0.75 Std. dev. () 1.13 1.12 2.74 3.13 3.03 3.18 COV 0.16 0.18 0.37 0.22 0.22 0.28 Design scour 2.91 1.88 0.22 1.25 0.89 1.18 Non exceedance 0.9982 0.9701 0.5857 0.8935 0.8143 0.8818 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 7.64 6.90 8.60 15.86 15.09 12.77 = 1.0 (0.8413) 8.19 7.46 10.17 17.65 16.79 14.55 = 1.5 (0.9332) 8.77 8.00 11.89 19.43 18.56 16.38 = 2.0 (0.9772) 9.34 8.55 13.56 21.32 20.40 18.21 = 2.5 (0.9938) 9.79 9.06 15.50 23.34 22.41 20.54 = 3.0 (0.9987) 10.26 9.44 17.24 25.29 24.82 22.31 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.07 0.86 0.92 0.84 = 1.0 (0.8413) 0.79 0.88 1.27 0.96 1.02 0.96 = 1.5 (0.9332) 0.85 0.95 1.48 1.06 1.13 1.08 = 2.0 (0.9772) 0.90 1.01 1.69 1.16 1.24 1.20 = 2.5 (0.9938) 0.95 1.07 1.93 1.27 1.36 1.36 = 3.0 (0.9987) 0.99 1.12 2.15 1.38 1.51 1.48 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 7.62 6.88 8.79 16.04 15.26 12.94 = 1.0 (0.8413) 8.18 7.45 10.16 17.60 16.77 14.53 = 1.5 (0.9332) 8.75 8.01 11.53 19.16 18.29 16.12 = 2.0 (0.9772) 9.32 8.57 12.91 20.73 19.80 17.72 = 2.5 (0.9938) 9.89 9.13 14.28 22.29 21.32 19.31 = 3.0 (0.9987) 10.45 9.69 15.65 23.86 22.84 20.90 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.74 0.82 1.10 0.87 0.93 0.86 = 1.0 (0.8413) 0.79 0.88 1.27 0.96 1.02 0.96 = 1.5 (0.9332) 0.85 0.95 1.44 1.04 1.11 1.07 = 2.0 (0.9772) 0.90 1.02 1.61 1.13 1.20 1.17 = 2.5 (0.9938) 0.96 1.08 1.78 1.21 1.30 1.28 = 3.0 (0.9987) 1.01 1.15 1.95 1.30 1.39 1.38
Summary of Scour Factors in Tabular and Graphical Form B-17 Table B.16 Medium BridgeâHigh Hydrologic UncertaintyâSmall Pier (1.5 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 3.60 3.19 8.02 11.62 11.21 15.12 Expected scour () 2.46 2.40 7.40 9.85 9.80 11.40 Bias 0.68 0.75 0.92 0.85 0.87 0.75 Std. dev. () 0.39 0.43 3.26 3.28 3.30 3.51 COV 0.16 0.18 0.44 0.33 0.34 0.31 Design scour 2.94 1.85 0.19 0.54 0.43 1.06 Non exceedance 0.9984 0.9679 0.5754 0.7046 0.6656 0.8553 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 2.65 2.61 8.77 11.22 11.18 12.87 = 1.0 (0.8413) 2.84 2.83 10.60 13.10 13.05 14.83 = 1.5 (0.9332) 3.04 3.05 12.52 15.04 15.03 16.99 = 2.0 (0.9772) 3.24 3.27 14.84 17.33 17.33 19.44 = 2.5 (0.9938) 3.43 3.47 17.67 20.00 20.00 22.33 = 3.0 (0.9987) 3.56 3.58 19.84 22.36 22.32 25.51 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.09 0.97 1.00 0.85 = 1.0 (0.8413) 0.79 0.89 1.32 1.13 1.16 0.98 = 1.5 (0.9332) 0.84 0.96 1.56 1.29 1.34 1.12 = 2.0 (0.9772) 0.90 1.02 1.85 1.49 1.55 1.29 = 2.5 (0.9938) 0.95 1.09 2.21 1.72 1.78 1.48 = 3.0 (0.9987) 0.99 1.12 2.47 1.93 1.99 1.69 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 2.65 2.61 9.02 11.49 11.45 13.16 = 1.0 (0.8413) 2.84 2.83 10.65 13.13 13.09 14.91 = 1.5 (0.9332) 3.04 3.04 12.28 14.77 14.74 16.67 = 2.0 (0.9772) 3.23 3.25 13.91 16.42 16.39 18.42 = 2.5 (0.9938) 3.43 3.47 15.54 18.06 18.04 20.18 = 3.0 (0.9987) 3.62 3.68 17.17 19.70 19.69 21.93 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.74 0.82 1.13 0.99 1.02 0.87 = 1.0 (0.8413) 0.79 0.89 1.33 1.13 1.17 0.99 = 1.5 (0.9332) 0.84 0.95 1.53 1.27 1.32 1.10 = 2.0 (0.9772) 0.90 1.02 1.74 1.41 1.46 1.22 = 2.5 (0.9938) 0.95 1.09 1.94 1.55 1.61 1.33 = 3.0 (0.9987) 1.01 1.15 2.14 1.70 1.76 1.45
B-18 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.17 Medium BridgeâHigh Hydrologic UncertaintyâMedium Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 7.20 5.94 8.02 15.22 13.95 15.12 Expected scour () 4.91 4.47 7.40 12.31 11.87 11.40 Bias 0.68 0.75 0.92 0.81 0.85 0.75 Std. dev. () 0.78 0.80 3.26 3.35 3.41 3.51 COV 0.16 0.18 0.44 0.27 0.29 0.31 Design scour 2.94 1.83 0.19 0.87 0.61 1.06 Non exceedance 0.9984 0.9667 0.5754 0.8073 0.7295 0.8553 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 5.30 4.86 8.77 13.74 13.32 12.87 = 1.0 (0.8413) 5.69 5.27 10.60 15.63 15.25 14.83 = 1.5 (0.9332) 6.07 5.69 12.52 17.62 17.25 16.99 = 2.0 (0.9772) 6.47 6.09 14.84 19.93 19.60 19.44 = 2.5 (0.9938) 6.85 6.50 17.67 22.53 22.32 22.33 = 3.0 (0.9987) 7.13 6.73 19.84 24.89 24.68 25.51 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.09 0.90 0.95 0.85 = 1.0 (0.8413) 0.79 0.89 1.32 1.03 1.09 0.98 = 1.5 (0.9332) 0.84 0.96 1.56 1.16 1.24 1.12 = 2.0 (0.9772) 0.90 1.03 1.85 1.31 1.41 1.29 = 2.5 (0.9938) 0.95 1.09 2.21 1.48 1.60 1.48 = 3.0 (0.9987) 0.99 1.13 2.47 1.64 1.77 1.69 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 5.30 4.87 9.02 13.98 13.57 13.16 = 1.0 (0.8413) 5.69 5.27 10.65 15.66 15.28 14.91 = 1.5 (0.9332) 6.08 5.67 12.28 17.33 16.98 16.67 = 2.0 (0.9772) 6.47 6.07 13.91 19.01 18.69 18.42 = 2.5 (0.9938) 6.86 6.47 15.54 20.69 20.40 20.18 = 3.0 (0.9987) 7.25 6.87 17.17 22.36 22.10 21.93 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.74 0.82 1.13 0.92 0.97 0.87 = 1.0 (0.8413) 0.79 0.89 1.33 1.03 1.10 0.99 = 1.5 (0.9332) 0.84 0.95 1.53 1.14 1.22 1.10 = 2.0 (0.9772) 0.90 1.02 1.74 1.25 1.34 1.22 = 2.5 (0.9938) 0.95 1.09 1.94 1.36 1.46 1.33 = 3.0 (0.9987) 1.01 1.16 2.14 1.47 1.58 1.45
Summary of Scour Factors in Tabular and Graphical Form B-19 Table B.18 Medium BridgeâHigh Hydrologic UncertaintyâLarge Pier (4.5 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 10.35 8.44 8.02 18.37 16.45 15.12 Expected scour () 7.06 6.36 7.40 14.46 13.75 11.40 Bias 0.68 0.75 0.92 0.79 0.84 0.75 Std. dev. () 1.15 1.14 3.26 3.64 3.56 3.51 COV 0.16 0.18 0.44 0.25 0.26 0.31 Design scour 2.87 1.82 0.19 1.08 0.76 1.06 Non exceedance 0.9979 0.9658 0.5754 0.8589 0.7756 0.8553 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 7.64 6.92 8.77 16.06 15.30 12.87 = 1.0 (0.8413) 8.23 7.51 10.60 18.08 17.27 14.83 = 1.5 (0.9332) 8.78 8.10 12.52 20.21 19.30 16.99 = 2.0 (0.9772) 9.39 8.69 14.84 22.54 21.72 19.44 = 2.5 (0.9938) 10.03 9.25 17.67 25.07 24.58 22.33 = 3.0 (0.9987) 10.45 9.64 19.84 27.20 27.00 25.51 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.09 0.87 0.93 0.85 = 1.0 (0.8413) 0.79 0.89 1.32 0.98 1.05 0.98 = 1.5 (0.9332) 0.85 0.96 1.56 1.10 1.17 1.12 = 2.0 (0.9772) 0.91 1.03 1.85 1.23 1.32 1.29 = 2.5 (0.9938) 0.97 1.10 2.21 1.36 1.49 1.48 = 3.0 (0.9987) 1.01 1.14 2.47 1.48 1.64 1.69 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 7.63 6.93 9.02 16.27 15.53 13.16 = 1.0 (0.8413) 8.21 7.50 10.65 18.09 17.32 14.91 = 1.5 (0.9332) 8.78 8.07 12.28 19.91 19.10 16.67 = 2.0 (0.9772) 9.36 8.64 13.91 21.73 20.88 18.42 = 2.5 (0.9938) 9.93 9.21 15.54 23.55 22.66 20.18 = 3.0 (0.9987) 10.51 9.78 17.17 25.37 24.44 21.93 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.74 0.82 1.13 0.89 0.94 0.87 = 1.0 (0.8413) 0.79 0.89 1.33 0.99 1.05 0.99 = 1.5 (0.9332) 0.85 0.96 1.53 1.08 1.16 1.10 = 2.0 (0.9772) 0.90 1.02 1.74 1.18 1.27 1.22 = 2.5 (0.9938) 0.96 1.09 1.94 1.28 1.38 1.33 = 3.0 (0.9987) 1.01 1.16 2.14 1.38 1.49 1.45
B-20 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.19 Large BridgeâLow Hydrologic UncertaintyâSmall Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 7.20 6.10 5.29 12.49 11.39 10.96 Expected scour () 4.90 4.56 4.95 9.85 9.51 8.28 Bias 0.68 0.75 0.93 0.79 0.83 0.76 Std. dev. () 0.78 0.81 1.93 2.08 2.11 3.24 COV 0.16 0.18 0.39 0.21 0.22 0.39 Design scour 2.97 1.90 0.18 1.28 0.89 0.83 Non exceedance 0.9985 0.9712 0.5711 0.8990 0.8140 0.7961 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 5.29 4.96 5.74 10.74 10.42 9.57 = 1.0 (0.8413) 5.69 5.38 6.86 11.89 11.59 11.47 = 1.5 (0.9332) 6.07 5.76 8.05 13.16 12.84 13.56 = 2.0 (0.9772) 6.44 6.19 9.35 14.46 14.21 15.70 = 2.5 (0.9938) 6.79 6.60 10.79 15.87 15.65 18.25 = 3.0 (0.9987) 7.10 6.85 12.55 17.68 17.62 21.51 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.81 1.08 0.86 0.91 0.87 = 1.0 (0.8413) 0.79 0.88 1.30 0.95 1.02 1.05 = 1.5 (0.9332) 0.84 0.95 1.52 1.05 1.13 1.24 = 2.0 (0.9772) 0.89 1.02 1.77 1.16 1.25 1.43 = 2.5 (0.9938) 0.94 1.08 2.04 1.27 1.37 1.66 = 3.0 (0.9987) 0.99 1.12 2.37 1.41 1.55 1.96 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 5.28 4.96 5.91 10.88 10.56 9.90 = 1.0 (0.8413) 5.67 5.37 6.88 11.92 11.62 11.52 = 1.5 (0.9332) 6.06 5.77 7.84 12.96 12.67 13.14 = 2.0 (0.9772) 6.45 6.18 8.80 14.00 13.73 14.76 = 2.5 (0.9938) 6.84 6.58 9.76 15.04 14.78 16.39 = 3.0 (0.9987) 7.22 6.99 10.73 16.07 15.84 18.01 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.81 1.12 0.87 0.93 0.90 = 1.0 (0.8413) 0.79 0.88 1.30 0.95 1.02 1.05 = 1.5 (0.9332) 0.84 0.95 1.48 1.04 1.11 1.20 = 2.0 (0.9772) 0.90 1.01 1.66 1.12 1.21 1.35 = 2.5 (0.9938) 0.95 1.08 1.84 1.20 1.30 1.49 = 3.0 (0.9987) 1.00 1.15 2.03 1.29 1.39 1.64
Summary of Scour Factors in Tabular and Graphical Form B-21 Table B.20 Large BridgeâLow Hydrologic UncertaintyâMedium Pier (6 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 13.77 11.28 5.29 19.07 16.57 10.96 Expected scour () 9.35 8.43 4.95 14.30 13.38 8.28 Bias 0.68 0.75 0.93 0.75 0.81 0.76 Std. dev. () 1.51 1.50 1.93 2.58 2.50 3.24 COV 0.16 0.18 0.39 0.18 0.19 0.39 Design scour 2.94 1.89 0.18 1.85 1.28 0.83 Non exceedance 0.9983 0.9707 0.5711 0.9677 0.8990 0.7961 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 10.11 9.18 5.74 15.50 14.56 9.57 = 1.0 (0.8413) 10.88 9.95 6.86 16.88 15.87 11.47 = 1.5 (0.9332) 11.62 10.68 8.05 18.30 17.26 13.56 = 2.0 (0.9772) 12.33 11.47 9.35 19.82 18.81 15.70 = 2.5 (0.9938) 13.03 12.21 10.79 21.28 20.34 18.25 = 3.0 (0.9987) 13.57 12.73 12.55 22.99 22.31 21.51 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.81 1.08 0.81 0.88 0.87 = 1.0 (0.8413) 0.79 0.88 1.30 0.89 0.96 1.05 = 1.5 (0.9332) 0.84 0.95 1.52 0.96 1.04 1.24 = 2.0 (0.9772) 0.90 1.02 1.77 1.04 1.13 1.43 = 2.5 (0.9938) 0.95 1.08 2.04 1.12 1.23 1.66 = 3.0 (0.9987) 0.99 1.13 2.37 1.21 1.35 1.96 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 10.10 9.19 5.91 15.59 14.63 9.90 = 1.0 (0.8413) 10.86 9.94 6.88 16.88 15.88 11.52 = 1.5 (0.9332) 11.61 10.69 7.84 18.17 17.13 13.14 = 2.0 (0.9772) 12.36 11.44 8.80 19.46 18.38 14.76 = 2.5 (0.9938) 13.12 12.19 9.76 20.75 19.63 16.39 = 3.0 (0.9987) 13.87 12.94 10.73 22.04 20.88 18.01 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.81 1.12 0.82 0.88 0.90 = 1.0 (0.8413) 0.79 0.88 1.30 0.89 0.96 1.05 = 1.5 (0.9332) 0.84 0.95 1.48 0.95 1.03 1.20 = 2.0 (0.9772) 0.90 1.01 1.66 1.02 1.11 1.35 = 2.5 (0.9938) 0.95 1.08 1.84 1.09 1.18 1.49 = 3.0 (0.9987) 1.01 1.15 2.03 1.16 1.26 1.64
B-22 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.21 Large BridgeâLow Hydrologic UncertaintyâLarge Pier (9 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 17.93 15.90 5.29 23.22 21.19 10.96 Expected scour () 12.19 11.89 4.95 17.14 16.84 8.28 Bias 0.68 0.75 0.93 0.74 0.79 0.76 Std. dev. () 1.97 2.13 1.93 2.93 2.96 3.24 COV 0.16 0.18 0.39 0.17 0.18 0.39 Design scour 2.91 1.89 0.18 2.08 1.47 0.83 Non exceedance 0.9982 0.9704 0.5711 0.9811 0.9296 0.7961 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 13.18 12.95 5.74 18.55 18.27 9.57 = 1.0 (0.8413) 14.19 14.03 6.86 20.07 19.79 11.47 = 1.5 (0.9332) 15.16 15.08 8.05 21.62 21.32 13.56 = 2.0 (0.9772) 16.11 16.20 9.35 23.31 23.08 15.70 = 2.5 (0.9938) 17.00 17.21 10.79 25.16 24.93 18.25 = 3.0 (0.9987) 17.72 17.95 12.55 26.86 26.66 21.51 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.81 1.08 0.80 0.86 0.87 = 1.0 (0.8413) 0.79 0.88 1.30 0.86 0.93 1.05 = 1.5 (0.9332) 0.85 0.95 1.52 0.93 1.01 1.24 = 2.0 (0.9772) 0.90 1.02 1.77 1.00 1.09 1.43 = 2.5 (0.9938) 0.95 1.08 2.04 1.08 1.18 1.66 = 3.0 (0.9987) 0.99 1.13 2.37 1.16 1.26 1.96 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 13.18 12.95 5.91 18.60 18.32 9.90 = 1.0 (0.8413) 14.16 14.02 6.88 20.07 19.80 11.52 = 1.5 (0.9332) 15.15 15.08 7.84 21.53 21.27 13.14 = 2.0 (0.9772) 16.13 16.14 8.80 23.00 22.75 14.76 = 2.5 (0.9938) 17.12 17.20 9.76 24.46 24.23 16.39 = 3.0 (0.9987) 18.10 18.27 10.73 25.93 25.71 18.01 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.81 1.12 0.80 0.86 0.90 = 1.0 (0.8413) 0.79 0.88 1.30 0.86 0.93 1.05 = 1.5 (0.9332) 0.84 0.95 1.48 0.93 1.00 1.20 = 2.0 (0.9772) 0.90 1.02 1.66 0.99 1.07 1.35 = 2.5 (0.9938) 0.95 1.08 1.84 1.05 1.14 1.49 = 3.0 (0.9987) 1.01 1.15 2.03 1.12 1.21 1.64
Summary of Scour Factors in Tabular and Graphical Form B-23 Table B.22 Large BridgeâMedium Hydrologic UncertaintyâSmall Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 7.20 6.10 5.29 12.49 11.39 10.96 Expected scour () 4.89 4.57 5.09 9.98 9.66 8.50 Bias 0.68 0.75 0.96 0.80 0.85 0.78 Std. dev. () 0.77 0.82 2.56 2.67 2.72 4.30 COV 0.16 0.18 0.50 0.27 0.28 0.51 Design scour 2.99 1.87 0.08 0.94 0.64 0.57 Non exceedance 0.9986 0.9691 0.5322 0.8274 0.7379 0.7165 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 5.28 4.99 6.08 11.04 10.76 9.96 = 1.0 (0.8413) 5.67 5.40 7.58 12.61 12.34 12.57 = 1.5 (0.9332) 6.06 5.81 9.31 14.32 14.06 15.55 = 2.0 (0.9772) 6.43 6.20 11.20 16.24 15.93 19.09 = 2.5 (0.9938) 6.76 6.56 13.22 18.19 18.01 22.78 = 3.0 (0.9987) 7.04 6.88 15.22 20.40 20.15 26.69 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.15 0.88 0.94 0.91 = 1.0 (0.8413) 0.79 0.89 1.43 1.01 1.08 1.15 = 1.5 (0.9332) 0.84 0.95 1.76 1.15 1.23 1.42 = 2.0 (0.9772) 0.89 1.02 2.12 1.30 1.40 1.74 = 2.5 (0.9938) 0.94 1.08 2.50 1.46 1.58 2.08 = 3.0 (0.9987) 0.98 1.13 2.87 1.63 1.77 2.44 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 5.28 4.98 6.37 11.31 11.02 10.65 = 1.0 (0.8413) 5.66 5.39 7.64 12.64 12.38 12.80 = 1.5 (0.9332) 6.05 5.80 8.92 13.98 13.74 14.95 = 2.0 (0.9772) 6.44 6.21 10.20 15.31 15.10 17.10 = 2.5 (0.9938) 6.82 6.61 11.48 16.64 16.46 19.25 = 3.0 (0.9987) 7.21 7.02 12.76 17.98 17.82 21.40 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.20 0.91 0.97 0.97 = 1.0 (0.8413) 0.79 0.88 1.44 1.01 1.09 1.17 = 1.5 (0.9332) 0.84 0.95 1.69 1.12 1.21 1.36 = 2.0 (0.9772) 0.89 1.02 1.93 1.23 1.33 1.56 = 2.5 (0.9938) 0.95 1.08 2.17 1.33 1.45 1.76 = 3.0 (0.9987) 1.00 1.15 2.41 1.44 1.56 1.95
B-24 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.23 Large BridgeâMedium Hydrologic UncertaintyâMedium Pier (6 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 13.77 11.28 5.29 19.07 16.57 10.96 Expected scour () 9.32 8.46 5.09 14.41 13.54 8.50 Bias 0.68 0.75 0.96 0.76 0.82 0.78 Std. dev. () 1.52 1.52 2.56 3.19 3.09 4.30 COV 0.16 0.18 0.50 0.22 0.23 0.51 Design scour 2.93 1.85 0.08 1.46 0.98 0.57 Non exceedance 0.9983 0.9681 0.5322 0.9278 0.8365 0.7165 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 10.08 9.23 6.08 15.82 14.87 9.96 = 1.0 (0.8413) 10.85 10.00 7.58 17.61 16.59 12.57 = 1.5 (0.9332) 11.63 10.78 9.31 19.50 18.42 15.55 = 2.0 (0.9772) 12.41 11.48 11.20 21.47 20.44 19.09 = 2.5 (0.9938) 13.05 12.16 13.22 23.59 22.77 22.78 = 3.0 (0.9987) 13.76 12.84 15.22 25.70 24.97 26.69 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.15 0.83 0.90 0.91 = 1.0 (0.8413) 0.79 0.89 1.43 0.92 1.00 1.15 = 1.5 (0.9332) 0.84 0.96 1.76 1.02 1.11 1.42 = 2.0 (0.9772) 0.90 1.02 2.12 1.13 1.23 1.74 = 2.5 (0.9938) 0.95 1.08 2.50 1.24 1.37 2.08 = 3.0 (0.9987) 1.00 1.14 2.87 1.35 1.51 2.44 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 10.08 9.22 6.37 16.00 15.09 10.65 = 1.0 (0.8413) 10.84 9.98 7.64 17.60 16.63 12.80 = 1.5 (0.9332) 11.60 10.74 8.92 19.20 18.18 14.95 = 2.0 (0.9772) 12.36 11.50 10.20 20.79 19.72 17.10 = 2.5 (0.9938) 13.12 12.26 11.48 22.39 21.27 19.25 = 3.0 (0.9987) 13.88 13.02 12.76 23.99 22.81 21.40 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.20 0.84 0.91 0.97 = 1.0 (0.8413) 0.79 0.88 1.44 0.92 1.00 1.17 = 1.5 (0.9332) 0.84 0.95 1.69 1.01 1.10 1.36 = 2.0 (0.9772) 0.90 1.02 1.93 1.09 1.19 1.56 = 2.5 (0.9938) 0.95 1.09 2.17 1.17 1.28 1.76 = 3.0 (0.9987) 1.01 1.15 2.41 1.26 1.38 1.95
Summary of Scour Factors in Tabular and Graphical Form B-25 Table B.24 Large BridgeâMedium Hydrologic UncertaintyâLarge Pier (9 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 17.93 15.90 5.29 23.22 21.19 10.96 Expected scour () 12.20 11.92 5.09 17.28 17.01 8.50 Bias 0.68 0.75 0.96 0.74 0.80 0.78 Std. dev. () 2.02 2.16 2.56 3.59 3.53 4.30 COV 0.17 0.18 0.50 0.21 0.21 0.51 Design scour 2.84 1.84 0.08 1.66 1.18 0.57 Non exceedance 0.9977 0.9672 0.5322 0.9510 0.8819 0.7165 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 13.20 13.01 6.08 18.85 18.60 9.96 = 1.0 (0.8413) 14.23 14.10 7.58 20.84 20.50 12.57 = 1.5 (0.9332) 15.26 15.25 9.31 22.99 22.53 15.55 = 2.0 (0.9772) 16.32 16.23 11.20 25.27 24.68 19.09 = 2.5 (0.9938) 17.26 17.27 13.22 27.52 27.32 22.78 = 3.0 (0.9987) 18.28 18.24 15.22 29.85 29.60 26.69 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.15 0.81 0.88 0.91 = 1.0 (0.8413) 0.79 0.89 1.43 0.90 0.97 1.15 = 1.5 (0.9332) 0.85 0.96 1.76 0.99 1.06 1.42 = 2.0 (0.9772) 0.91 1.02 2.12 1.09 1.16 1.74 = 2.5 (0.9938) 0.96 1.09 2.50 1.18 1.29 2.08 = 3.0 (0.9987) 1.02 1.15 2.87 1.29 1.40 2.44 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 13.21 13.00 6.37 19.08 18.78 10.65 = 1.0 (0.8413) 14.22 14.08 7.64 20.87 20.54 12.80 = 1.5 (0.9332) 15.23 15.16 8.92 22.67 22.31 14.95 = 2.0 (0.9772) 16.24 16.24 10.20 24.46 24.07 17.10 = 2.5 (0.9938) 17.25 17.32 11.48 26.25 25.84 19.25 = 3.0 (0.9987) 18.26 18.40 12.76 28.05 27.60 21.40 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.74 0.82 1.20 0.82 0.89 0.97 = 1.0 (0.8413) 0.79 0.89 1.44 0.90 0.97 1.17 = 1.5 (0.9332) 0.85 0.95 1.69 0.98 1.05 1.36 = 2.0 (0.9772) 0.91 1.02 1.93 1.05 1.14 1.56 = 2.5 (0.9938) 0.96 1.09 2.17 1.13 1.22 1.76 = 3.0 (0.9987) 1.02 1.16 2.41 1.21 1.30 1.95
B-26 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.25 Large BridgeâHigh Hydrologic UncertaintyâSmall Pier (3 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 7.20 6.10 5.29 12.49 11.39 10.96 Expected scour () 4.90 4.58 5.26 10.16 9.84 8.79 Bias 0.68 0.75 0.99 0.81 0.86 0.80 Std. dev. () 0.77 0.81 3.16 3.24 3.32 5.33 COV 0.16 0.18 0.60 0.32 0.34 0.61 Design scour 2.99 1.86 0.01 0.72 0.47 0.41 Non exceedance 0.9986 0.9686 0.5039 0.7642 0.6796 0.6582 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 5.29 5.00 6.45 11.38 11.16 10.63 = 1.0 (0.8413) 5.67 5.40 8.35 13.30 13.09 13.83 = 1.5 (0.9332) 6.06 5.80 10.48 15.49 15.28 17.57 = 2.0 (0.9772) 6.45 6.20 12.99 17.95 17.77 22.21 = 2.5 (0.9938) 6.82 6.60 15.76 20.66 20.41 27.26 = 3.0 (0.9987) 7.08 6.81 18.06 23.13 23.10 32.80 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.22 0.91 0.98 0.97 = 1.0 (0.8413) 0.79 0.89 1.58 1.06 1.15 1.26 = 1.5 (0.9332) 0.84 0.95 1.98 1.24 1.34 1.60 = 2.0 (0.9772) 0.90 1.02 2.45 1.44 1.56 2.03 = 2.5 (0.9938) 0.95 1.08 2.98 1.65 1.79 2.49 = 3.0 (0.9987) 0.98 1.12 3.41 1.85 2.03 2.99 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 5.28 4.99 6.84 11.78 11.50 11.45 = 1.0 (0.8413) 5.67 5.40 8.42 13.40 13.16 14.12 = 1.5 (0.9332) 6.05 5.80 10.00 15.02 14.82 16.79 = 2.0 (0.9772) 6.44 6.21 11.58 16.65 16.48 19.45 = 2.5 (0.9938) 6.82 6.62 13.16 18.27 18.13 22.12 = 3.0 (0.9987) 7.21 7.02 14.74 19.89 19.79 24.78 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.29 0.94 1.01 1.04 = 1.0 (0.8413) 0.79 0.88 1.59 1.07 1.16 1.29 = 1.5 (0.9332) 0.84 0.95 1.89 1.20 1.30 1.53 = 2.0 (0.9772) 0.89 1.02 2.19 1.33 1.45 1.77 = 2.5 (0.9938) 0.95 1.09 2.48 1.46 1.59 2.02 = 3.0 (0.9987) 1.00 1.15 2.78 1.59 1.74 2.26
Summary of Scour Factors in Tabular and Graphical Form B-27 Table B.26 Large BridgeâHigh Hydrologic UncertaintyâMedium Pier (6 ) Pier Scour (HEC 18) Pier Scour (FDOT) ContracÂon Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 13.77 11.28 5.29 19.07 16.57 10.96 Expected scour () 9.31 8.48 5.26 14.57 13.74 8.79 Bias 0.68 0.75 0.99 0.76 0.83 0.80 Std. dev. () 1.53 1.52 3.16 3.79 3.68 5.33 COV 0.16 0.18 0.60 0.26 0.27 0.61 Design scour 2.92 1.84 0.01 1.19 0.77 0.41 Non exceedance 0.9983 0.9672 0.5039 0.8826 0.7796 0.6582 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 10.05 9.24 6.45 16.16 15.29 10.63 = 1.0 (0.8413) 10.84 10.02 8.35 18.24 17.28 13.83 = 1.5 (0.9332) 11.63 10.78 10.48 20.62 19.72 17.57 = 2.0 (0.9772) 12.43 11.53 12.99 23.32 22.25 22.21 = 2.5 (0.9938) 13.26 12.28 15.76 25.83 24.94 27.26 = 3.0 (0.9987) 13.79 12.70 18.06 28.62 27.83 32.80 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.73 0.82 1.22 0.85 0.92 0.97 = 1.0 (0.8413) 0.79 0.89 1.58 0.96 1.04 1.26 = 1.5 (0.9332) 0.84 0.96 1.98 1.08 1.19 1.60 = 2.0 (0.9772) 0.90 1.02 2.45 1.22 1.34 2.03 = 2.5 (0.9938) 0.96 1.09 2.98 1.35 1.51 2.49 = 3.0 (0.9987) 1.00 1.13 3.41 1.50 1.68 2.99 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 10.07 9.24 6.84 16.46 15.58 11.45 = 1.0 (0.8413) 10.84 10.00 8.42 18.36 17.42 14.12 = 1.5 (0.9332) 11.60 10.76 10.00 20.25 19.25 16.79 = 2.0 (0.9772) 12.36 11.52 11.58 22.14 21.09 19.45 = 2.5 (0.9938) 13.13 12.28 13.16 24.03 22.93 22.12 = 3.0 (0.9987) 13.89 13.04 14.74 25.93 24.77 24.78 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.73 0.82 1.29 0.86 0.94 1.04 = 1.0 (0.8413) 0.79 0.89 1.59 0.96 1.05 1.29 = 1.5 (0.9332) 0.84 0.95 1.89 1.06 1.16 1.53 = 2.0 (0.9772) 0.90 1.02 2.19 1.16 1.27 1.77 = 2.5 (0.9938) 0.95 1.09 2.48 1.26 1.38 2.02 = 3.0 (0.9987) 1.01 1.16 2.78 1.36 1.49 2.26
B-28 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction Table B.27 Large BridgeâHigh Hydrologic UncertaintyâLarge Pier (9 ) Pier Scour (HEC 18) Pier Scour (FDOT) Contrac on Scour Total Scour (HEC 18) Total Scour (FDOT) Abutment Scour Design scour () 17.93 15.90 5.29 23.22 21.19 10.96 Expected scour () 12.23 11.95 5.26 17.49 17.22 8.79 Bias 0.68 0.75 0.99 0.75 0.81 0.80 Std. dev. () 2.06 2.16 3.16 4.25 4.11 5.33 COV 0.17 0.18 0.60 0.24 0.24 0.61 Design scour 2.76 1.82 0.01 1.35 0.97 0.41 Non exceedance 0.9971 0.9658 0.5039 0.9113 0.8335 0.6582 Scour Non exceedance () Based on Monte Carlo Results = 0.5 (0.6915) 13.23 13.03 6.45 19.25 19.02 10.63 = 1.0 (0.8413) 14.27 14.15 8.35 21.59 21.20 13.83 = 1.5 (0.9332) 15.35 15.27 10.48 24.36 23.76 17.57 = 2.0 (0.9772) 16.55 16.27 12.99 27.29 26.54 22.21 = 2.5 (0.9938) 17.73 17.36 15.76 30.43 29.62 27.26 = 3.0 (0.9987) 18.69 17.99 18.06 33.56 32.75 32.80 Scour Factors Based on Monte Carlo Results = 0.5 (0.6915) 0.74 0.82 1.22 0.83 0.90 0.97 = 1.0 (0.8413) 0.80 0.89 1.58 0.93 1.00 1.26 = 1.5 (0.9332) 0.86 0.96 1.98 1.05 1.12 1.60 = 2.0 (0.9772) 0.92 1.02 2.45 1.18 1.25 2.03 = 2.5 (0.9938) 0.99 1.09 2.98 1.31 1.40 2.49 = 3.0 (0.9987) 1.04 1.13 3.41 1.44 1.55 2.99 Scour Non exceedance ( ) Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 13.26 13.03 6.84 19.62 19.27 11.45 = 1.0 (0.8413) 14.29 14.12 8.42 21.74 21.32 14.12 = 1.5 (0.9332) 15.33 15.20 10.00 23.87 23.38 16.79 = 2.0 (0.9772) 16.36 16.28 11.58 25.99 25.43 19.45 = 2.5 (0.9938) 17.39 17.36 13.16 28.11 27.49 22.12 = 3.0 (0.9987) 18.42 18.45 14.74 30.24 29.54 24.78 Scour Factors Based on Scour Mean and Standard Deviaon = 0.5 (0.6915) 0.74 0.82 1.29 0.84 0.91 1.04 = 1.0 (0.8413) 0.80 0.89 1.59 0.94 1.01 1.29 = 1.5 (0.9332) 0.85 0.96 1.89 1.03 1.10 1.53 = 2.0 (0.9772) 0.91 1.02 2.19 1.12 1.20 1.77 = 2.5 (0.9938) 0.97 1.09 2.48 1.21 1.30 2.02 = 3.0 (0.9987) 1.03 1.16 2.78 1.30 1.39 2.26
Summary of Scour Factors in Tabular and Graphical Form B-29 (a) (b) Figure B.1. Scour factors for the HEC-18 pier scour equation. 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 0.50 1.00 1.50 2.00 2.50 3.00 Sc ou rF ac to r Reliability Index ( ) HEC 18 Pier Scour Monte Carlo Results SB LH SP SB LH MP SB LH LP SB MH SP SB MH MP SB MH LP SB HH SP SB HH MP SB HH LP MB LH SP MB LH MP MB LH LP MB MH SP MB MH MP MB MH LP MB HH SP MB HH MP MB HH LP LB LH SP LB LH MP LB LH LP LB MH SP LB MH MP LB MH LP LB HH SP LB HH MP LB HH LP 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.05 0.50 1.00 1.50 2.00 2.50 3.00 Sc ou rF ac to r Reliability Index ( ) HEC 18 Pier Scour Statis cal Results SB LH SP SB LH MP SB LH LP SB MH SP SB MH MP SB MH LP SB HH SP SB HH MP SB HH LP MB LH SP MB LH MP MB LH LP MB MH SP MB MH MP MB MH LP MB HH SP MB HH MP MB HH LP LB LH SP LB LH MP LB LH LP LB MH SP LB MH MP LB MH LP LB HH SP LB HH MP LB HH LP HEC-18 Pier Scour â te C rlo Results
B-30 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction (a) (b) Figure B.2. Scour factors for the Florida DOT (FDOT) pier scour equation. 0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.15 1.20 0.50 1.00 1.50 2.00 2.50 3.00 Sc ou rF ac to r Reliability Index ( ) FDOT Pier Scour Monte Carlo Results SB LH SP SB LH MP SB LH LP SB MH SP SB MH MP SB MH LP SB HH SP SB HH MP SB HH LP MB LH SP MB LH MP MB LH LP MB MH SP MB MH MP MB MH LP MB HH SP MB HH MP MB HH LP LB LH SP LB LH MP LB LH LP LB MH SP LB MH MP LB MH LP LB HH SP LB HH MP LB HH LP 0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.15 1.20 0.50 1.00 1.50 2.00 2.50 3.00 Sc ou rF ac to r Reliability Index ( ) FDOT Pier Scour Statis cal Results SB LH SP SB LH MP SB LH LP SB MH SP SB MH MP SB MH LP SB HH SP SB HH MP SB HH LP MB LH SP MB LH MP MB LH LP MB MH SP MB MH MP MB MH LP MB HH SP MB HH MP MB HH LP LB LH SP LB LH MP LB LH LP LB MH SP LB MH MP LB MH LP LB HH SP LB HH MP LB HH LP i r r â Monte Carlo Results
Summary of Scour Factors in Tabular and Graphical Form B-31 (a) (b) Figure B.3. Scour factors for contraction scour. 1.00 1.50 2.00 2.50 3.00 3.50 0.50 1.00 1.50 2.00 2.50 3.00 Sc ou rF ac to r Reliability Index ( ) Contraction Scour Monte Carlo Results SB LH SB MH SB HH MB LH MB MH MB HH LB LH LB MH LB HH 1.00 1.50 2.00 2.50 3.00 3.50 0.50 1.00 1.50 2.00 2.50 3.00 Sc ou rF ac to r Reliability Index ( ) Contraction Scour Sta s cal Results SB LH SB MH SB HH MB LH MB MH MB HH LB LH LB MH LB HH
B-32 Reference Guide for Applying Risk and Reliability-Based Approaches for Bridge Scour Prediction (a) (b) Figure B.4. Scour factors for the NCHRP Project 24-20 abutment scour equation. 0.50 1.00 1.50 2.00 2.50 3.00 0.50 1.00 1.50 2.00 2.50 3.00 Sc ou rF ac to r Reliability Index ( ) Abutment Scour Monte Carlo Results SB LH SB MH SB HH MB LH MB MH MB HH LB LH LB MH LB HH 0.50 1.00 1.50 2.00 2.50 3.00 0.50 1.00 1.50 2.00 2.50 3.00 Sc ou rF ac to r Reliability Index ( ) Abutment Scour Statis cal Results SB LH SB MH SB HH MB LH MB MH MB HH LB LH LB MH LB HH
Abbreviations and acronyms used without deï¬nitions in TRB publications: A4A Airlines for America AAAE American Association of Airport Executives AASHO American Association of State Highway Officials AASHTO American Association of State Highway and Transportation Officials ACIâNA Airports Council InternationalâNorth America ACRP Airport Cooperative Research Program ADA Americans with Disabilities Act APTA American Public Transportation Association ASCE American Society of Civil Engineers ASME American Society of Mechanical Engineers ASTM American Society for Testing and Materials ATA American Trucking Associations CTAA Community Transportation Association of America CTBSSP Commercial Truck and Bus Safety Synthesis Program DHS Department of Homeland Security DOE Department of Energy EPA Environmental Protection Agency FAA Federal Aviation Administration FHWA Federal Highway Administration FMCSA Federal Motor Carrier Safety Administration FRA Federal Railroad Administration FTA Federal Transit Administration HMCRP Hazardous Materials Cooperative Research Program IEEE Institute of Electrical and Electronics Engineers ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITE Institute of Transportation Engineers MAP-21 Moving Ahead for Progress in the 21st Century Act (2012) NASA National Aeronautics and Space Administration NASAO National Association of State Aviation Officials NCFRP National Cooperative Freight Research Program NCHRP National Cooperative Highway Research Program NHTSA National Highway Traffic Safety Administration NTSB National Transportation Safety Board PHMSA Pipeline and Hazardous Materials Safety Administration RITA Research and Innovative Technology Administration SAE Society of Automotive Engineers SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (2005) TCRP Transit Cooperative Research Program TEA-21 Transportation Equity Act for the 21st Century (1998) TRB Transportation Research Board TSA Transportation Security Administration U.S.DOT United States Department of Transportation
