HYDRAULIC JUSTIFICATION OF THE WATER OUTLET CONDUIT PARAMETERS IN CONNECTION WITH THE DON MAIN CANAL RECONSTRUCTION (2ND PHASE OF THE II RECONSTRUCTION STAGE)

Purpose: calculation substantiation of the Don Main Canal outlet conduit parameters, which would ensure reliable and safe operation, as well as reduced risks of flooding and damage, for their adaptation to new hydraulic conditions. Materials and methods. Based on data analysis for the Don Main Canal section, calculations of the headrace, transit part and discharge channel were performed. According to the materials and design features, the pipeline diameter was determined in accordance with the passing flow rate. The discharge channel was calculated based on the required diversion capacity as the most hydraulically advantageous with the monolithic reinforced concrete channel slopes and the bottom fastening. Results. For the most critical part of the structure, within which the turbulent flow is coupled with a calm one using a hydraulic jump and complete excess kinetic energy dissipation of the flow, the form of flow conjugation was established. It was found that we have a stable form of pool conjugation according to the type of a submerged jump (the third type of conjugation), the beginning of which is located within the pipe and the apron minimum dimensions are determined. Conclusions. The obtained results of hydraulic calculations allow us to conclude that the narrowing of the design cross-section of the channel under the bridge and above the storm drains requires channel lining, since it causes the water level rise above the maximum, while the channel fixing with stone is impossible due to the water level rise above the permissible. Lining the channel with reinforced concrete slabs allows passing the design flow of 110 cub. m/s without exceeding the maximum level and at permissible flow rates. The need to justify the materials and design solutions to ensure the effective and safe operation of the water outlet conduit on the Don Main Canal was taken into account during the hydraulic calculation of the structure parameters.