Calculation method for design longitudinal shrinking slope of ladder-pool debris flow drainage groove and application

Abstract

The invention discloses a calculation method for a design longitudinal shrinking slope of a ladder-pool debris flow drainage groove and an application. The calculation method determines the average longitudinal shrinking slope of a natural channel, the total design length of the drainage groove and the suspending height of a ladder section in the site selection range of the drainage groove firstly; and then the dimensionless parameter slope ratio and pool configuration density are determined; the quantity of a deep pool section is determined; finally, the design longitudinal shrinking slope of the ladder-pool debris flow drainage groove is determined by the calculation formula of the design longitudinal shrinking slope. The method is based on strict theoretical derivation, defines the dimensionless parameter with a physical significance and determines the design longitudinal shrinking slope of the ladder-pool debris flow drainage groove rationally so as to provide a basis to the profile design of the drainage groove; the calculation is simple and convenient; the calculation result is high in precision and adaptable to the needs of actual projects.

Description

technical field

[0001] The invention relates to a method for measuring and calculating the vertical gradient of a ladder-deep pool structure type debris flow drainage channel suitable for a large trench bed longitudinal gradient and debris flow ditch, and its application in the design of the longitudinal section of the ladder-deep pool type debris flow drainage channel Applications. 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...

Examples

Embodiment 1

[0049] Such as figure 1 shown. A debris flow ditch is located in the northwest of Mianzhu City, on the left bank of the Mianyuan River. It is a typical representative of debris flow ditch with multiple sources, large gradient and small watershed after the earthquake. Groove area: 1.36km 2 ; Main ditch length: 2.59km; highest point elevation: 1980m; ditch mouth elevation: 960m; relative height difference: 1020m; average vertical gradient: 625‰. Before the earthquake, the ditch was a mountain torrent ditch. After the 5.12 earthquake, the middle and upper mountain body produced a collapse debris flow, which accumulated in the ditch and formed a debris flow under the action of rainfall. From June 2008 to September 2011, a total of 5000m 3 More than 10 times of the above mudslide activities not only buried the Hanwang-Qingping Highway, the lifeline of the ditch mouth, but also blocked the Mianyuan River many times, forming a mudslide barrier lake. After engineering treatment, d...

Embodiment 2

[0059] Such as figure 1 shown. A debris flow ditch is located in the north of Qingpingchang Town in the northwest mountainous area of ​​Mianzhu City, Sichuan Province. In terms of landform, it belongs to tectonic erosion cutting steep low-middle mountain landform, slope and gully landform. The watershed generally extends east-west, the main ditch is in the shape of "7", the cross-section is a combination of "V" and "U", and the catchment area is 7.81km 2 , the total length of the main ditch is 3.25km, the lowest point in the basin is located at the mouth of the ditch at an altitude of 883m, and the highest peak is located at Dingziya of Jiuding Mountain in the eastern part of the watershed, with an altitude of 2402m and a relative height of 1519m. The average longitudinal slope of the trench bed is 458.5‰. There have been many large-scale debris flows in the ditch, which pose a great threat to Qingping Township.

[0060] In order to effectively guide debris flow and reduce...

technical field

[0001] The invention relates to a method for measuring and calculating the vertical gradient of a ladder-deep pool structure type debris flow drainage channel suitable for a large trench bed longitudinal gradient and debris flow ditch, and its application in the design of the longitudinal section of the ladder-deep pool type debris flow drainage channel Applications. 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...

Examples

Embodiment 1

[0049] Such as figure 1 shown. A debris flow ditch is located in the northwest of Mianzhu City, on the left bank of the Mianyuan River. It is a typical representative of debris flow ditch with multiple sources, large gradient and small watershed after the earthquake. Groove area: 1.36km 2 ; Main ditch length: 2.59km; highest point elevation: 1980m; ditch mouth elevation: 960m; relative height difference: 1020m; average vertical gradient: 625‰. Before the earthquake, the ditch was a mountain torrent ditch. After the 5.12 earthquake, the middle and upper mountain body produced a collapse debris flow, which accumulated in the ditch and formed a debris flow under the action of rainfall. From June 2008 to September 2011, a total of 5000m 3 More than 10 times of the above mudslide activities not only buried the Hanwang-Qingping Highway, the lifeline of the ditch mouth, but also blocked the Mianyuan River many times, forming a mudslide barrier lake. After engineering treatment, d...

Embodiment 2

[0059] Such as figure 1 shown. A debris flow ditch is located in the north of Qingpingchang Town in the northwest mountainous area of ​​Mianzhu City, Sichuan Province. In terms of landform, it belongs to tectonic erosion cutting steep low-middle mountain landform, slope and gully landform. The watershed generally extends east-west, the main ditch is in the shape of "7", the cross-section is a combination of "V" and "U", and the catchment area is 7.81km 2 , the total length of the main ditch is 3.25km, the lowest point in the basin is located at the mouth of the ditch at an altitude of 883m, and the highest peak is located at Dingziya of Jiuding Mountain in the eastern part of the watershed, with an altitude of 2402m and a relative height of 1519m. The average longitudinal slope of the trench bed is 458.5‰. There have been many large-scale debris flows in the ditch, which pose a great threat to Qingping Township.

[0060] In order to effectively guide debris flow and reduce...

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