Use of dispersing springboards to reduce near-bottom velocity in a toe basin
It is noted that the load that develops under high near-bottom velocities should be consider when analyzing the loads on a toe-basin slab in the case of high-head hydroprojects. They may not only create significant forces against the surface of the slabs, but also give rise to the appearance of suspending forces, which act on blocks of the toe—basin slab of the apron. To reduce near-bottom velocities, it is recommended that a group of dispersing springboards with a double-curved surface be incorporated in the terminal section of the spillway. Numerical modeling of the operating regime of the basin indicates that a submerged hydraulic jump is formed here in the basin, while near-bottom velocities are reduced by more than a factor of two, and, consequently, a more than fourfold reduction occurs in the load.