The National Academies Press

Currently Skimming:

Pages 162-183

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.

From page 162... ... 160 APPENDIX SCOUR-DEPTH ESTIMATION METHODS A.1 INTRODUCTION This appendix briefly evaluates existing methods for estimating scour depth. It includes methods proposed prior to 1990 though focussing especially on methods developed since 1990. Read the entire page →
From page 163... ... 161 Chitale (1962) Read the entire page →
From page 164... ... 162 May and Willoughby (1990)              = sm sc sc s ss y y y yfy 4.2 For circular cylinder: fs 0.10.1 0.152.0166.31 76.1 >= ≤≤      −−= c ccsc s V V V V V V y y = 1.0 0.10.1 7.255.0 6.0 >= ≤     = a y a y a y y y sm sc Breusers and Raudkivi (1991) Read the entire page →
From page 165... ... 163 Melville (1997) θKKKKKy sdIybs = θKKKKy sdybs = Kyb K = 2.4a y/a > 1.4 yb = 2(ya) Read the entire page →
From page 166... ... 164 Miller and Sheppard (2002) Read the entire page →
From page 167... ... 165 Table A-2 Dimensionless parameters included in the selected pier scour equations (The table is divided to indicate methods proposed since 1990) Reference y/a a/D Pier Shape Pier Alignment V/V Inglis (1949) Read the entire page →
From page 168... ... 166 parameter y/a* defines the scale of the pier flow field (a* Read the entire page →
From page 169... ... 167 completeness of evaluation, all the equations discussed in the previous section are included in the plots, either individually or in combination for cases where the original equation by a certain author has been replaced or augmented by a newer equation; e.g. the Melville (1997) Read the entire page →
From page 170... ... 168 Figure A-1 Comparison of normalized local scour depth predictions using 22 different equations/methods for transition from clear-water to live-bed scour conditions. Pier width large compared to the water depth, fine sand. Read the entire page →
From page 171... ... 169 Figure A-2 Comparison of normalized local scour depth predictions using 22 different equations/methods for a particular live-bed scour condition. Pier width large compared to the water depth, fine sand. Read the entire page →
From page 172... ... 170 Figure A-3 Comparison of normalized local scour depth predictions using 22 different equations/methods for transition from clearwater to live-bed scour conditions. Pier width equal to water depth, fine sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s / a V1/Vc=1, y1/a=1, D50=0.2 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 173... ... 171 Figure A-4 Comparison of normalized local scour depth predictions using 22 different equations/methods for a particular live-bed scour condition. Pier width equal to water depth, fine sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s / a V1/Vc=3, y1/a=1, D50=0.2 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 174... ... 172 Figure A-5 Comparison of normalized local scour depth predictions using 22 different equations/methods for transition from clearwater to live-bed scour conditions. Deep water relative to pier width, fine sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s / a V1/Vc=1, y1/a=3, D50=0.2 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 175... ... 173 Figure A-6 Comparison of normalized local scour depth predictions using 22 different equations/methods for a particular live-bed scour condition. Deep water relative to pier width, fine sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s / a V1/Vc=3, y1/a=3, D50=0.2 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 176... ... 174 Figure A-7 Comparison of normalized local scour depth predictions using 22 different equations/methods for transition from clearwater to live-bed scour conditions. Pier width large compared to water depth, very coarse sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s / a V1/Vc=1, y1/a=0.33, D50=3 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 177... ... 175 Figure A-8 Comparison of normalized local scour depth predictions using 22 different equations/methods for a particular live-bed scour condition. Pier width large relative to water depth, fine sand, very coarse sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s / a V1/Vc=3, y1/a=0.33, D50=3 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 178... ... 176 Figure A-9 Comparison of normalized local scour depth predictions using 22 different equations/methods for transition from clear-water to live-bed scour conditions. Pier width equal to water depth, very coarse sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s / a V1/Vc=1, y1/a=1, D50=3 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 179... ... 177 Figure A-10 Comparison of normalized local scour depth predictions using 22 different equations/methods for a particular live-bed scour condition. Pier width equal to water depth, very coarse sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s / a V1/Vc=3, y1/a=1, D50=3 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 180... ... 178 Figure A-11 Comparison of normalized local scour depth predictions using 22 different equations/methods for transition from clearwater to live-bed scour conditions. Deep water relative to pier width, very coarse sand. Read the entire page →
From page 181... ... 179 Figure A-12 Comparison of normalized local scour depth predictions using 22 different equations/methods for a particular live-bed scour condition. Deep water relative to pier width, very coarse sand 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Ing lis1 94 9 Ah ma d 1 95 3 La urs en 19 58 -63 Ch ita le 19 62 La rra s 1 96 3 Br eu se rs 19 65 Ble nc h 1 96 9 Sh en 19 69 Co lem an 19 71 Ha nc u 1 97 1 Ne ill 19 73 Br eu se rs 19 77 Ja in 19 81 Fro eh lich 19 81 Ma y 1 99 0 Br eu se rs 19 91 Ga o 1 99 3 An sa ri 1 99 4 Wi lso n 1 99 4 Me lvil le 19 97 Ric ha rds on 20 01 Sh ep pa rd 20 06 y s /a V1/Vc=3, y1/a=3, D50=3 mm a=0.05 m a=1 m a=10 m Read the entire page →
From page 182... ... 180 The methods used in Figures A-1 through A-12 were developed during the period 1949 to 2006. Improvements in the understanding of pier scour processes inevitably have resulted in improvements to scour-depth predictive methods. Read the entire page →
From page 183... ... 181 appraisal in NCHRP Project 24-32, also requires further consideration. The two methods yield overall comparable estimates of scour depth in the assessment shown in Section A.4. Read the entire page →

From page 162...

... 160 APPENDIX SCOUR-DEPTH ESTIMATION METHODS A.1 INTRODUCTION This appendix briefly evaluates existing methods for estimating scour depth. It includes methods proposed prior to 1990 though focussing especially on methods developed since 1990.