Shaft spillway is one of the spillway types used to pass additional waters and floods from the upstream to the downstream of dams.
Keywords: Shaft spillway, Discharge coefficient, Submergence, flow pattern
Shaft spillway is a spillway composed of a circular crest that directs the flow to an inclined or vertical axis, which is connected to a low gradient tunnel.
One of the major water conveyance structures that can act as an emergency spillway is shaft spillway. This type of spillway is so effective when there is not adequate space to build other types of spillways.
In this chamber, which is like a metal mesh screens, a series of straw was used to slow the flow that the water passes through the second buffer and entered the reservoir of the shaft spillway. The reservoir of the shaft spillway is sizes 1.2 x 1.1 x 1.2 meter which is completely enclosed from three sides and on the other hand, to observe the phenomenon inside the reservoir, a glass sheet with a thickness of 10 mm and a scale connected to reservoir glass was used to measure the height of the water on the shaft spillway.
To compare sharp triangular vortex breaker blades with rectangular body according to Figures (2) and (3) on the efficiency of the discharge of shaft spillway, 6 vortex breakers in three different lengths of 10, 15 and 20% of the overflow diameter with a thickness of 2 cm and a height of 4 cm m are used.
--bigger cracks, deformation, tilt in shaft spillway 33 ED (12.7%);
The same amount of deformation, tilt in shaft spillway has been registered in Lithuanian dams (12.7%).
The shaft spillway is one of the spillways used in the dams.
Through experimental investigation of the effect of the bend arc radius on shaft spillway flow hydraulic, Youssefvand et al.