Experimental study on energy dissipation of annular overflow shaft

Abstract

The annular shaft, which is widely used in tailings and some large and medium water conservancy project, has the characteristics of simple structure and strong discharge capacity. With the increase of working head, the energy dissipation problem of shaft is becoming much important. Model test results shows that the peak of the hydrodynamic pressure at the bottom of the shaft happens when the water jet merge together, for the water depth H in the shaft is low then, the pre-excavated hydrostatic depth is the main factor of energy dissipation. The fitting formula of the maximum impact pressure is obtained and it is suggested that the energy dissipation depth h should be 0.8D.