IMPROVEMENT OF NAVIGATION CONDITIONS ON THE IRTYSH RIVER IN THE SEMEY AREA BASED ON HYBRID MODELING

Abstract

The article presents the results of a comprehensive study aimed at improving navigable conditions in the limiting section of the Irtysh River in the Semey area (Upper and Lower Zhanasemeisky ridges, 2900-2904 km of navigation). The research is based on the methodology of hybrid (combined) hydraulic modeling, which integrates numerical calculations in the HEC-RAS software package and experiments on a spatial physical model. The purpose of the work is a comparative analysis of the effectiveness and justification of the parameters of two variants of regulating hydraulic structures (longitudinal and transverse dams) to ensure guaranteed depths during the inter–ice period. Verification of the numerical model and calibration of the physical model based on field observations were carried out. It was found that both options provide a significant increase in water levels (up to 92 cm for the longitudinal and up to 62 cm for the transverse dam) at an intermediate flow rate of 625 m3/s. A negative effect in the form of a cross-jet flow (up to 1.5 m/s) was identified and quantified for the option with a longitudinal dam, which required correction of its position. Using a semi-collapsible physical model, morphodynamic processes during the flood period (flow rate of 3500 m3/s) were studied and areas of potential erosion threatening the stability of structures were identified. Engineering measures to protect against erosion (reinforcement with flexible reinforced concrete mats and boulder filling) have been developed and tested on the model for each variant. The complementarity and high efficiency of combining numerical and physical modeling methods to obtain reliable and integrated engineering solutions are proved.