Design features of protective slopes of bridge supports across small watercourses on pressure sections of the sea shores

This article examines some of the complex natural factors that must be taken into account when designing bridge supports built across the mouths of small watercourses and railway tracks running along the pressure sections of the shores of the seas. Pressing areas are defined as places where the earthbed is bounded on one side by steep slopes, and on the other by the sea or watercourses that do not have coastal terraces. The issues of engineering protection of bridge supports and the roadbed of transport structures that are exposed to the most unfavorable combination of hydrological phenomena – river flooding and sea storm surges of rare frequency – are considered.
The research was carried out using the method of physical modeling. Physical modeling of coastal and riverbed processes was performed in a deep-sea wave basin. The simulation is performed at a scale of 1 : 40. At the same time, the simultaneous passage of a flood on a river of 1% availability and a sea storm with a repeatability of 1 every 25 years was reproduced. The stability of the protective wave-damping band in the estuary region was assessed. A variant of the layout of nano-retaining structures and a wave-extinguishing strip with the width necessary to dampen the rolling energy in order to protect the roadbed was investigated.
The purpose of the research is to assess bottom deformations in the estuarine zone under the simultaneous influence of storm waves and a river stream of a calculated flood.
According to the results of physical modeling, deformations of profiles in the estuarine part of the river and in the estuarine zone of the sea were obtained. The model defines the zones of erosion and accumulation of material removed from the riverbed by flood waters. The bottom deformation model (change in depths) and, as a result, the change in wave heights and the location of wave collapse should be taken into account when calculating the parameters of engineering protection structures for bridge crossings.
The research results can be used to correct mathematical models of hydrodynamic processes in the coastal zone of the seas near the mouths of watercourses.

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