Hi Chris,
I am conducting a hydraulic analysis to study the impacts of a small head dam approximately 16 m upstream of an existing bridge. The small head dam is modeled as inline structure using sharp-crested weir.
The predicted proposed condition water levels upstream of in-line structure are higher than the existing water levels for smaller flows (< 84 m3/s) as expected. The predicted proposed condition water levels upstream of in-line structure are lower than the existing conditions for higher flows (> 84 m3/s). The existing conditions flows does not overtop the bridge but dam by the bridge deck and flow under the bridge for higher flows. With inline structures water levels at bridge are much lower than the bridge deck.
could it be due to the fact that bridge and in-line structure are too close? is the water level upstream of in-line structure determined by the weir equation without considering the downstream bridge?
Any thoughts on this issue are appreciated.
Thanks.
Sundar