A method for measuring the maximum uplift height of viscous debris flow and its application

Abstract

The invention discloses a method for calculating the maximum uplift height of a viscous debris flow and its application. The method takes the mud level line of the viscous debris flow in the natural channel as the reference line, and the maximum distance of the vertical reference line on the mud level line when the viscous debris flow encounters an obstacle is the maximum height of the viscous debris flow; Determine the bulk density γc of the viscous debris flow, the angle θ between the direction of debris flow movement and the channel obstacle, the average longitudinal ratio drop J of the debris flow channel, the viscosity coefficient η, the yield stress τB and the flow depth of the debris fluid above the original channel surface H, so as to determine the maximum rushing height value of the obstacle encountered by the debris flow during the movement. The calculation result of this method is high in accuracy and simple in calculation. It is used for the design of the safety height of debris flow blocking engineering and meets the needs of the project.

Description

technical field [0001] The invention relates to a method for measuring and calculating the maximum rush-up height of a viscous mud-rock flow when encountering an obstacle, and its application in determining the design height of a prevention and control project, belonging to the field of mud-rock flow prevention and control. Background technique [0002] Debris flow disaster is one of the main types of mountain disasters, causing hundreds of millions of dollars in economic losses every year. At present, engineering prevention and control is the most effective measure to prevent and control debris flow disasters. However, during the long-term use of prevention and control projects, the damage caused by debris flows to the prevention and control projects cannot be ignored. Even if these projects are damaged, the scale of debris flows will increase on the original basis, greatly increasing the damage caused by debris flows. For example, in 2010, the large mudslide disaster in Z...

AI Technical Summary

Problems solved by technology

For example, if a sand dam is built in a debris flow channel, the debris flow will encounter the sand dam during its progress and cause the debris flow to turn over the non-overflow section of the sand dam and scour the dam abutment and the slope behind the dam, which will easily cause the sand dam unstable

According to the "Code for Design of Debris Flow Prevention and Control Engineering" (DZ / T0239-2004), the non-overflow section of the sand check dam is 0.5-1.0m higher than the overflow section. In this case, only the overflow when the dam body is silted to full storage capacity The dam height design of the dam part ignores the scour generated by the impact of debris flow on the sand check dam, which will easily cause the debris flow to overturn the non-overflow section of the sand check dam, scour the abutment and the slope behind the dam, and cause damage

Existing debris flow calculations mainly use the energy method to analyze the debris flow as a whole. The resulting height is the height of the overall center of gravity of the debris flow. Obviously, the height of the center of gravity is lower than the actual height of the debris flow. It reflects the difference in flow velocity distribution of debris flow within the flow depth range; and the formula is simple, without considering the characteristics of the debris flow itself and the nature of the channel, the accuracy of the calculated value is not high, and it is easy to cause hidden dangers to the protection engineering design

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