Investigation of the impact of the construction of a bridge crossing over the river. Oka (Nizhny Novgorod) on the upstream waterways using mathematical modeling of the riverbed flow

For the projected bridge crossing over the river. An assessment of the impact of its construction on the reliability of operation of upstream aqueducts in the riverbed was carried out in Nizhny Novgorod. These conduits are subject to erosion and to assess the impact of the bridge supports being erected on the condition of the conduits, three-dimensional mathematical modeling of the river flow in the studied river area was performed. The simulation is based on a system of Navier-Stokes equations. The k-e turbulence model is used to describe turbulent phenomena. The three-dimensional geometry of the area under study includes the riverbed, bridge supports, and culverts. The performed mathematical modeling of the section of the river The Oka in the area of the aqueducts in two states – in natural (before the construction of the bridge) and operational (after the bridge was put into operation) at low inter-soil levels allowed us to conclude that there was practically no effect of the bridge supports on further erosion of the bottom in the area of the aqueducts. Also, dredging, which is necessary to maintain navigation on an additional ship's course in the sleeve, does not affect the erosion of the bottom under the pipes of the aqueducts. The results of the work are intended for use in the design and construction of the facility.