| Summary: | 碩士 === 逢甲大學 === 土木及水利工程所 === 92 === This study uses SMS-TABS-RAM2 2D unsteady flow model. This model analyses Wu River on the downstream of Shuang-Dong Bridge in different peak flow. The numerical solution of the previously investigated 1D HEC-RAS model bow wave is compared to SMS-TABS 2D model. These numerical models can achieve reliable flow forecast, thus providing reliable information and references for bridge engineers. This study also compares the differences between the results obtained from Empirical Equations of bow wave with the results obtained from SMS-TABS-RAM2 2D model study.
This study includes 3 flow patterns, namely 100 years, 50 years and 20 years return flood peak flow. It simulates Wu River Shuang-Dong Bridge’s water level, stream velocity and the affected region of back flow (from pier resistance). From the results of the 3 flow patterns, the deepest pier will have the highest bow wave. The maximum bow wave is 0.95m at pier No. 5. The maximum stream velocity is 4.9 m/sec between pier No. 8 and pier No. 9. The affected region of backflow reaches 16m at upstream, and reaches 16m at downstream. The length of affected region is 1/10 of the river width. This model study result is compared with 1D formula of D’Aubuioson, Nagler and Yarnell. It is found that D’Aubuioson 1D formula result deviates very much from the other two formulae results. Furthermore, D’Aubuioson formula computed with a negative value for the bow wave height. Therefore, this value is not adopted. As for the Nagler and Yarnell formulae, the computed results are more conservative than the SMS-TABS-RAM2 2D model study result, but in similar trend.
|
|---|
