Dependence of actual filling level of gravity flow water distribution on sediment thickness in benching part of pipes

Abstract

The regulatory requirements of SP 32.13330.2018 (Sewerage. Pipelines and wastewater treatment plants) set the minimum sewage velocity in water distribution systems, depending on the highest filling level of pipes. It is known that during the operation of gravity flow water distribution systems under certain conditions, a layer of internal sediments might be formed, which increases the filling level of pipes and changes the values of the hydraulic characteristics of the flow. The study suggests the dependence between the values of hydraulic characteristics of the flow and the amount of internal sediments on the surface where the sewage flows. The authors introduced the calculated dependencies for hydraulic calculation of gravity flow water distribution systems with sediments on the surface where the sewage is moving. The study confirmed the dependence of the actual filling level of gravity flow water distribution systems on the amount of sediments on the surface. A specific example confirming the existence of such a dependence was given. The paper presented a graph of dependence between actual filling level and sediment thickness in benching part of pipes. It was shown that during the operation of gravity flow water distribution systems with internal sediments it is necessary to control the value of the actual filling of pipes 𝐻ф 𝑑пр and the amount of sediment in their benching part ℎ, which have a significant impact on the values of the hydraulic characteristics of the sewage flow.