Spillway Profile With Breast Wall

Spillway Profile With Breast Wall

Spillway Profile With Breast Wall

  • Spillways, generally the ogee-crested type, are sometimes provided with a breast wall from various considerations such as increasing the regulating storage of flood  discharge, reducing the height of the gate, minimizing the cost of gate operating mechanism, etc. 

For the spillways with breast wall, the following parameters are required to be determined:

  1. Profile of the spillway crest including the upstream and downstream quadrants, 

  2. Profile of the bottom surface of the breast wall, and 

  3. Estimation of discharge efficiency of the spillway. 

  • The flow through a spillway with breast wall has been idealised as two-dimensional flow through a sharp edged orifice in a large tank. The following guidelines for determining the parameters mentioned above may be used for preparing preliminary designs and studies on hydraulic model may be conducted for confirming or improving on the preliminary design. Figure 36 shows pertinent details of various profiles of the spillway with a breast wall.