Overflowing treatment method for linear water retaining structure under two-dimensional non-structural flood numerical simulation framework

Abstract

The invention discloses an overflowing treatment method of a linear water retaining structure under a two-dimensional non-structural flood numerical simulation framework. After topographic and geomorphological data of a calculation area and geometric feature data of the linear water retaining structure are obtained, a quadrilateral non-structural grid discrete calculation area is adopted, and thecenter line of the linear water retaining structure serves as a control line of grid division. After grid division is completed, grid unit edges representing the linear water retaining structure are defined as special edges, and the rest unit edges are defined as boundary edges and common edges. The weir flow form is judged according to the ratio of the top width of the linear structure to the upstream water depth of the linear structure, the unit width flow passing through the special edge is calculated through a corresponding weir flow formula, and the mass flux and the momentum flux passingthrough the special edge in the outer normal direction are obtained. According to the treatment method, the mass exchange process and the momentum exchange process of the two sides of the linear structure can be considered while the calculation efficiency is considered, and the defects of an existing method are overcome.

Description

technical field [0001] The invention belongs to the technical field of water conservancy engineering, and in particular relates to a flow-through treatment method of a linear water-retaining structure under a two-dimensional non-structural flood numerical simulation framework. Background technique [0002] The so-called linear water-retaining structures refer to structures such as expressway embankments, railway embankments, and water-retaining embankments that are often encountered in the calculation area. The tops of these structures are usually higher than the ground, and their spatial forms are linear. When a flood occurs, these structures will play an obvious role in blocking water, and when the water level on one side is greater than the elevation of the top, overflow will occur. [0003] In engineering practice, a two-dimensional shallow water model is usually used to simulate a large-scale flood flow process. In the calculation of two-dimensional flood numerical sim...

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Problems solved by technology

At present, there are two commonly used methods to deal with these linear structures under the framework of two-dimensional non-structural numerical simulation. One is to use a fine grid to separate the linear structures, which requires very fine terrain data to support, but when When performing large-scale flood analysis, on the one hand, the cost of obtaining such fine terrain is too high; on the other hand, although the numerical accuracy of this kind of processing is high, it will bring catastrophic calculation efficiency problems at the same time, so in practical applications The other is a very simplified treatment method, which uses the wide-crested weir flow formula to directly transfer the water flow through the top of the linear water-retaining structure to the downstream grid, and only considers the water exchange on both sides of the linear water-retaining structure. However, the exchange of water flow on both sides is ignored, and the different weir flow characteristics at the top of the linear water retaining structure are usually not distinguished, which will have a great impact on the actual calculation accuracy

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