Effect of seepage on river bank stability
An experiment- based study was conducted in a laboratory flume to investigate the correlation between river bank stability and the erosion forces of seepage under unidirectional current. The study involved the collapse of a bank slope made up of a non cohesive soil (sand) using only the channel flo...
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| Format: | Final Year Project (FYP) |
| Language: | English |
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2009
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| Online Access: | http://hdl.handle.net/10356/16079 |
| _version_ | 1826129180892332032 |
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| author | Nandakumar Narasimhan |
| author2 | Chiew Yee Meng |
| author_facet | Chiew Yee Meng Nandakumar Narasimhan |
| author_sort | Nandakumar Narasimhan |
| collection | NTU |
| description | An experiment- based study was conducted in a laboratory flume to investigate the correlation between river bank stability and the erosion forces of seepage under unidirectional current. The study involved the collapse of a bank slope made up of a non cohesive soil (sand) using only the channel flow and ground water flow as erosion forces. Whereas most studies hitherto have focused on the two forces individually (i.e. seepage and current effects separately), this study combined the two forces and studied their combined effect on the failure of the slope. The dimensionless Reynolds number for bed shear stress was plotted against the safety factor for the slope using an analytical expression. It was found that an increased channel flow velocity (hence an increased shear stress and shear velocity) facilitated the collapse of the slope and caused it to collapse at a lower hydraulic gradient than one with very slow flow velocity. However there exists a certain critical value for the Reynolds number beyond which the fluvial erosion forces become significant in causing slope failure. The analytical expression that was determined for submerged slope stability fails at higher flow velocities as it gives a higher factor of safety when it was experimentally observed that the slope failed at lower hydraulic gradients. |
| first_indexed | 2024-10-01T07:36:49Z |
| format | Final Year Project (FYP) |
| id | ntu-10356/16079 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:36:49Z |
| publishDate | 2009 |
| record_format | dspace |
| spelling | ntu-10356/160792023-03-03T17:27:10Z Effect of seepage on river bank stability Nandakumar Narasimhan Chiew Yee Meng School of Civil and Environmental Engineering DRNTU::Engineering::Civil engineering::Water resources An experiment- based study was conducted in a laboratory flume to investigate the correlation between river bank stability and the erosion forces of seepage under unidirectional current. The study involved the collapse of a bank slope made up of a non cohesive soil (sand) using only the channel flow and ground water flow as erosion forces. Whereas most studies hitherto have focused on the two forces individually (i.e. seepage and current effects separately), this study combined the two forces and studied their combined effect on the failure of the slope. The dimensionless Reynolds number for bed shear stress was plotted against the safety factor for the slope using an analytical expression. It was found that an increased channel flow velocity (hence an increased shear stress and shear velocity) facilitated the collapse of the slope and caused it to collapse at a lower hydraulic gradient than one with very slow flow velocity. However there exists a certain critical value for the Reynolds number beyond which the fluvial erosion forces become significant in causing slope failure. The analytical expression that was determined for submerged slope stability fails at higher flow velocities as it gives a higher factor of safety when it was experimentally observed that the slope failed at lower hydraulic gradients. Bachelor of Engineering (Environmental Engineering) 2009-05-20T08:37:59Z 2009-05-20T08:37:59Z 2009 2009 Final Year Project (FYP) http://hdl.handle.net/10356/16079 en Nanyang Technological University 58 p. application/pdf |
| spellingShingle | DRNTU::Engineering::Civil engineering::Water resources Nandakumar Narasimhan Effect of seepage on river bank stability |
| title | Effect of seepage on river bank stability |
| title_full | Effect of seepage on river bank stability |
| title_fullStr | Effect of seepage on river bank stability |
| title_full_unstemmed | Effect of seepage on river bank stability |
| title_short | Effect of seepage on river bank stability |
| title_sort | effect of seepage on river bank stability |
| topic | DRNTU::Engineering::Civil engineering::Water resources |
| url | http://hdl.handle.net/10356/16079 |
| work_keys_str_mv | AT nandakumarnarasimhan effectofseepageonriverbankstability |