Measuring and calculating method for length of deep pool segment of step-deep pool type debris flow drainage canal

Abstract

The invention discloses a measuring and calculating method for the length of a deep pool segment of a step-deep pool type debris flow drainage canal. According to the measuring and calculating method, firstly, the unit weight of a debris flow body, the designed longitudinal slope of the drainage canal, the casting angle of debris flow, the designed suspension height of a step segment, the designed width of the drainage canal and the designed peak flow of the drainage canal are determined; then the roughness factor of the drainage canal, the permissible velocity and the overflowing mud depth of the debris flow are determined; afterwards, the average velocity of a debris flow cross section is determined, and the permissible velocity is compared with the average velocity of the debris flow cross section; and finally, the length of the deep pool segment of the step-deep pool type debris flow drainage canal is determined through a measuring and calculating formula of the deep pool segment. Proceeding from the complete movement process of fluid in the canal, the method is based on strict theoretical derivation, and the influence of the properties of the debris flow on the casting range is considered in combination with experiments, so that the length of the deep pool segment of the step-deep pool type debris flow drainage canal is determined reasonably, and a basis is provided for the design of the step-deep pool type drainage canal; the precision of a calculated result is high; the method is adapted to the actual requirement of engineering.

Description

technical field

[0001] The invention relates to a method for measuring and calculating the length of the deep pool section of a ladder-deep pool structure type debris flow drainage channel suitable for a large ditch bed longitudinal gradient. Background technique

[0002] Geological disasters occur frequently in our country. Debris flow, as one of the main mountain disasters, has seriously affected people's life and property safety, production and life, and has also had a certain restrictive effect on the economic development of mountainous areas. Especially after the "5.12" Wenchuan Ms8.0 earthquake, the debris flow activities in the earthquake area have the characteristics of easy blockage, low critical rainfall, high frequency, and high bulk density due to the rich source of matter and superior topographical conditions. The debris flow activities are concentrated in the basin area <5km 2 1. The vertical slope of the channel is > 20%, or even 50% on the channel or s...

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