Channeling design method for reservoir capacity recovery in front of high floodland and deep-cut channel reservoir dam

Abstract

The invention discloses a channeling design method for reservoir capacity recovery in front of a high floodland and deep-cut channel reservoir dam, and belongs to the technical field of water conservancy project desilting. Due to the fact that a natural main channel and a floodland exist on the upstream of the dam, the high position of the floodland at the drought period is exposed above the riversurface, and channeling construction operations can be executed with small-sized equipment; then water is led into the channel before the floor season of the river, and floodland silt outside the channel is made to collapse; and finally the reservoir water level is lowered to discharge the silt, and thus the reservoir capacity in front of the dam can be recovered. By adoption of the method, the wet soil boundary in the critical state is subjected to stability against sliding checking calculation, the designed channeling depth is determined, and the optimal excavation gradient inside the channel is calculated through the starting speed of the silt. By means of the method disclosed by the invention, the design and construction scheme is simple, no large-sized hoisting equipment and carryingequipment are required, and the cost is low and reasonable; and moreover, the water level fluctuation law is ingeniously utilized, natural scouring and collapsing happen to soil bodies, time and labor are saved, the sand-contained water flow concentration inside the dug channel is high during desilting, the desilting effect is good and the channeling design method is suitable for small-sized heavily silt-carrying river tributaries and large-and-medium-sized heavily silt-carrying river main streams.

Description

technical field [0001] The invention belongs to the technical field of sand discharge in water conservancy projects, and in particular relates to a design method for excavating high beaches and deep grooves before dams to restore storage capacity. Background technique [0002] Reservoirs on sandy rivers will reduce the effective storage capacity and shorten the service life of the reservoir due to sedimentation. Most of the rivers in northern my country are such rivers, and the runoff is unevenly distributed throughout the year. Many water conservancy projects have been built to regulate water volume. The construction of water conservancy projects can effectively improve the flood control capacity of rivers and play an important role in the development of upstream and downstream industrial and agricultural economies. However, the reality of high sediment content in rivers has caused serious siltation in northern reservoirs. The sediment entering the reservoir has encroached...

AI Technical Summary

Problems solved by technology

However, mechanical dredging has the following disadvantages: (1) The transportation conditions of mountainous reservoirs are poor, and it is difficult to carry dredging equipment and silted soil; (2) The dredging equipment has high operating costs and a small operating range; When the degree of sedimentation is not high and the concentration of muddy water is low, the dredging efficiency will also decrease, and there is uncertainty.

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