Introduction. Low water crossing structures made of corrugated metal constructions (hereinafter referred to as CMp), despite having a history of over a century of use, are still quite a new type of structure in Ukraine and are gaining widespread use in transportation construction as an alternative to traditional steel or concrete bridge structures. The well-known advantages that justify the choice of such a solution mainly include the short construction period and relatively low cost. Construction, provided the appropriate technological process is followed, does not pose significant challenges. However, the current design and construction process of low water crossing structures with CMp is imperfect and constantly improving. Some local features require the construction of a low water crossing pipe with a steep slope, which increases the speed of the water and creates a high-energy flow at the exit of the low water crossing pipe. This high-energy water can erode the natural streambed. The most effective method for dissipating excess kinetic energy from the water flow is by using a hydraulic jump. An analysis of the characteristics of the junctions of the pools for road water-crossing pipes in flat problems was conducted, the impact of various factors on the length of the hydraulic jump was determined, and a methodological approach to solving the junction problems was presented.
Problems. It has been established that there is a need to refine the existing approaches to the junction of pools for road water-crossing structures made of corrugated metal constructions, taking into account global practices.
Objectives. The main objectives of this scientific work are to study the junction of pools for low water crossing pipes in the context of a flat problem, to determine the influence of a number of factors on the length of the hydraulic jump, and to present a methodological approach to solving the problems of pool junctions.
Results. An analysis of the operational experience and the features of the functioning of water crossing structures made of corrugated metal constructions on highways has been conducted. The characteristics of the junction of pools for low water crossing pipes in the context of a flat problem have been studied. A methodological approach to solving the problems of pool junctions has been established.
The most effective way to dissipate excess kinetic energy of the water flow is through the use of a hydraulic jump. However, the issues related to the kinematics of the flow at the formation of the hydraulic jump and its stability are poorly researched. The controlling influence on the flow in the spreading zone of active-type dissipator structural elements for relatively wide and narrow channels has not been well studied.
Since in the area of the two-dimensional flow in plan the flow transforms into a three-dimensional one with a high level of anisotropic turbulence, at the current stage, only a statistical approach using methods from the theory of mathematical experiment design is possible for solving such problems.
When forming the flow with specified hydraulic characteristics, it is advisable to use the control principle – targeted influence on the flow using structural elements of the lower pool.
Using the differential form of the liquid motion equation allows for the derivation of the equation for the ideal hydraulic jump in the form explicitly related to the unknown second conjugate depth in the case of rough water conduits with a sloping bed.
The analysis of the general solution equation for the hydraulic jump showed that the influence of external friction forces and the sloping bed on the height of the hydraulic jump can be considered separately, independently of each other.
The analysis of the current state of the problem leads to the conclusion that the existing methods for calculating the junction of pools are imperfect, and there is a need to improve the current approaches to the calculations.
