Development of physical and mathematical models of the duker to calculate the critical length of its sections between supports on the riverbed

Moscow State University of Civil Engineering, 26, Yaroslavskoye shosse, Moscow, 129337, Russia

^* Corresponding author: dim.p-2010@yandex.ru

Abstract

The issues related to the construction and diagnosis of ducker crossings, signs of their operable condition are considered, with an emphasis on the development of a mathematical model for determining the critical length of the underwater pipeline spans between its supports in an unstable riverbed. A water-filled steel ducker of a certain diameter and wall thickness is subject to consideration for calculating the critical length, where a set of initial data necessary for design and construction is determined on the basis of initial technical, hydraulic and strength parameters. The results of the automated calculation are presented, which reflect the values of the following parameters: drag forces, Reynolds numbers, Froude criteria, pipeline weight, pushing and stretching forces, longitudinal stresses in the pipe wall from internal pressure and tensile force. On the basis of the obtained printouts of the results of the automated calculation, an analysis of the possible change in the value of the critical length of the ducker transition between the supports in the case of correction or clarification of some parameters regarding changes in the flow rates of water in the river and the permissible value of the deflection boom of the pipeline between the supports was carried out.