Inland river ecological channel scale design method

Abstract

The invention relates to an inland river ecological channel scale design method, and belongs to the field of water conservancy projects. Determining a designed ship type according to channel operation requirements, calculating a designed channel scale, and selecting a ship-to-ground navigation speed; channel background flow characteristics are analyzed and calculated according to water flow characteristics of a river where the channel is located; analyzing ecological threshold values of fishes and benthos in the area where the engineering is located; establishing a designed ship type, and respectively calculating ship hydrodynamic conditions under downstream and countercurrent conditions; according to the determined threshold values, maximum values of influence ranges in the width direction and the depth direction of the outer side channel of the ship body are taken as ecological surplus width and depth of ship navigation respectively; calculating the width and depth of an ecological channel according to the determined ecological surplus width and depth; comparing with a design channel scale recommended according to specifications, and comprehensively determining an ecological channel scale; the method has high practicability and operability, fills the blank of an ecological channel scale design method, and enriches related theories and methods of the ecological channel.

Description

Technical Field

[0001] The invention belongs to the field of water conservancy engineering, relates to the field of water transport science and technology, and in particular to a method for designing the scale of an inland ecological waterway. Background Art

[0002] There is no unified framework for the definition, connotation, design method, and evaluation of ecological waterways at home and abroad, and many studies are still in the initial stage, but the core idea of ​​combining waterway construction with ecological protection is basically the same. Ecological waterways are built on the basis of habitat needs and shipping needs, and the concept of ecology runs through the entire process of waterway construction, thus forming a new type of waterway with "smooth shipping, ecological friendliness, resource conservation, and coordinated development" as its fundamental characteristics.

[0003] Inland waterways refer to channels used for ship navigation in inland waters; while the scale of ecological waterways refers to the scale of waterways that can simultaneously meet the basic navigation needs of ships and the requirements of ecological protection. Since there is no clear definition of the scale of ecological waterways, there is no clear design method for the scale of waterways that meet ecological needs, and there are no relevant research results for reference. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a method for designing the scale of an inland ecological waterway.

[0005] To achieve the above object, the technical solution adopted by the present invention is: An inland river ecological waterway scale design method includes the following steps: S1. Determine the design ship type and control ship type according to the waterway operation requirements, calculate the design waterway scale, and select the ship's navigation speed over the ground; S2. Analyze and calculate the background flow characteristics of the channel under different guarantee rates according to the water flow characteristics of the river where the channel is located; the background flow characteristics of the channel include the background flow velocity and the background flow direction of the channel; S3. Analyze the ecological thresholds of fish, benthic organisms, and typical aquatic organisms in the project area; S4. Establish a ship model of the designed ship type, and combine the background flow velocity of the channel and the ship's navigation speed over the ground. Use the computational fluid dynamics model to carry out numerical simulation experiments to calculate the hydrodynamic conditions of the ship's navigation waters under downstream and upstream conditions respectively; S5. Based on the threshold value determined in step S3, the velocity and turbulence intensity influence ranges of each group calculated in step S4 are analyzed, and the maximum values ​​of the influence ranges in the width and depth directions of the channel outside the hull are taken as the ecologically rich width and ecologically rich depth of the ship's navigation, respectively; S6, calculating the ecological channel width and the ecological channel depth based on the ecological rich width and the ecological rich depth determined in step S5; S7. Compare the width and depth of the ecological channel with the design channel width and depth calculated using the formula recommended by the specification, and comprehensively determine the scale of the ecological channel.

[0006] Preferably, the hydrodynamic conditions of the ship's navigation waters include hydrodynamic flow velocity and hydrodynamic turbulence intensity indicators.

[0007] Preferably, in step S1, the design of the representative ship type and the control ship type scale are determined according to the "Inland River Navigation Standards", "Yangtze River Trunk Navigation Standards", and "Canal Navigation Standards"; the ship's navigation speed over the ground is determined according to the relevant requirements of navigation management and ship navigation experience; In step S2, the water flow velocity and flow direction data of the river where the waterway is located in different seasons and time periods are collected, the flow velocity distribution of the waterway to be studied is analyzed by frequency, the flow velocity at different guarantee rates of 25%, 50%, 75% and 90% is calculated, and the background flow characteristics of the waterway used in the scale design of the ecological waterway are comprehensively determined.

[0008] Preferably, in step S3, the ecological thresholds affecting the growth of aquatic organisms mainly include flow velocity tolerance thresholds, turbulence intensity tolerance thresholds, and sound wave and element tolerance thresholds.

[0009] Preferably, in step S4, the computational fluid dynamics model includes Flow-3D, Fluent, CFX, Star-CCM+, and Openfoam models, a ship model of the designed ship type is established, the channel background flow velocity and the ship's navigation speed over the ground are combined, and a calibrated and verified computational fluid dynamics model software is used to carry out three-dimensional hydrodynamic numerical simulation.

[0010] Preferably, in step S5, according to the ecological threshold determined in step S3, ecological threshold contour lines are drawn in the velocity, turbulence and element results diagram calculated in step S4 to analyze the ecological impact range, and the maximum value of the impact range in the width and depth direction of the channel outside the hull is taken as the ecological rich width and ecological rich depth of the ship's navigation.

[0011] Preferably, in step S6, the calculation formula for the width of the ecological waterway is: B e =B Fd +B Fu +d e1 +d e2 +C B Fd =B Sd +L d sinβ B Fu =B Su +L u sinβ Among them, Be B is the width of the straight double-line ecological channel; Fd B is the width of the downstream ship track; Fu is the width of the upstream ship track; d e1 is the ecologically rich width from the outer side of the downstream ship to the edge of the channel, and is determined according to the calculation result of step S5; d e2 is the ecologically rich width from the outer side of the upstream ship to the edge of the channel, determined according to the calculation result of step S5; B Sd L is the width of the downstream ship; d is the length of the downstream ship; β is the ship's drift angle, of which 3° is acceptable for Class I to Class V waterways, and 2° for Class V and Class VII waterways; B Su is the width of the upstream ship; L u is the length of the upstream ship; C is the safe distance when ships meet each other, taking the width of the upstream and downstream ships B Su and B Sd The maximum value of The calculation formula for the ecological channel depth is: e =T+ΔH e

[0012] Where: H e is the depth of the ecological channel; T is the ship's design draft or operating draft; ΔH e is the ecological rich depth, which is determined according to the calculation result of step S5, and the maximum value of the ecological rich depth of the downstream and upstream ships should be taken during the calculation.

[0013] Preferably, in step S7, the formula recommended by the specification mainly refers to the waterway dimension calculation formula specified in the "Inland Waterway Navigation Standards", "Canal Navigation Standards", "Waterway Engineering Design Standards" and the Ministry of Transport specifications.

[0014] Preferably, in step S7, When the width Be and depth He of the ecological channel are less than or equal to the width and depth of the designed channel, the scale of the ecological channel shall be the scale of the designed channel; When the scale of the ecological waterway is larger than the scale of the designed waterway but within 1.5 times of the scale of the designed waterway, the scale of the waterway determined in step S6 is taken as the scale of the ecological waterway; When the scale of the ecological channel is more than 1.5 times the scale of the design channel, the ship speed and the background flow velocity can be adjusted, and steps S4 to S7 can be repeated until the scale of the ecological channel that reduces the navigation efficiency but meets the ecological requirements is obtained.

[0015] Due to the adoption of the above technical solution, the beneficial effects obtained by the present invention include: The ecological waterway scale design method disclosed in the present invention has a clear concept, strong practicability and operability, fills the gap in the ecological waterway scale design method, and enriches the relevant theories and methods of the ecological waterway. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of an embodiment of the inland ecological waterway scale design method of the present invention.

[0017] Figure 2 It is a flow chart of a specific embodiment of the inland ecological waterway scale design method of the present invention.

[0018] Figure 3 It is a typical three-dimensional view of a ship in an embodiment of the inland ecological waterway scale design method of the present invention.

[0019] Figure 4 It is a model test hull grid diagram of an embodiment of the inland ecological waterway scale design method of the present invention.

[0020] Figure 5 It is a free surface waveform diagram of a ship's navigation in an embodiment of the inland ecological waterway scale design method of the present invention.

[0021] Figure 6 It is a diagram of the ship navigation flow field changes in an embodiment of the inland ecological waterway scale design method of the present invention. DETAILED DESCRIPTION

[0022] like Figure 1-6 As shown, a method for designing the scale of an inland ecological waterway in the present invention provides a quantitative design method for the scale design of an ecological waterway. In this embodiment, taking the scale design of an inland ecological waterway as an example, the specific implementation process of the present invention is described in detail: S1. According to the waterway operation requirements, determine the design ship type including the design representative ship type and other control ship types; calculate the design waterway scale and select the appropriate ship's navigation speed over the ground.

[0023] According to the waterway development plan, the waterway grade is inland waterway II, which can accommodate 2,000-ton ships. According to the Inland Waterway Navigation Standard (GB 50139), the representative ship type is designed with a total length of 90m, a beam of 15.4m, and a designed draft of 2.6m (Table 1).

[0024] Table 1 Channel grades and representative ship types

[0025] According to the channel dimension calculation formula recommended by the Inland Navigation Standard (GB 50139) or the Channel Engineering Design Code (JTS 181), the designed channel depth is 3.0m, the channel width is 70m, and the channel slope is 1:3 (Table 2). According to the relevant requirements of navigation management and ship navigation experience, the ship's ground navigation speed is selected as 15km / h.

[0026] Table 2 Design channel dimensions

[0027]

[0028] S2. According to the flow characteristics of the river where the waterway is located, the background flow characteristics of the waterway under different guarantee rates are analyzed and calculated; in S2, the water flow velocity and flow direction data of the river where the waterway is located in different seasons and time periods are collected, and the flow velocity distribution of the waterway to be studied is analyzed by frequency, and the flow velocity under different guarantee rates such as 5%, 10%, 25%, 50%, 75%, 90%, and 95% is used to comprehensively determine the background flow characteristics of the waterway (including flow velocity and flow direction) used in the scale design of the ecological waterway.

[0029] According to the analysis of the measured flow velocity and direction data in the proposed inland ecological waterway hydrological test, the flow velocity is 0.5m / s at a 75% guarantee rate, and the flow direction is from upstream to downstream along the deep trough.

[0030] S3. Analyze the ecological thresholds of fish, benthic organisms or typical aquatic organisms in the area where the project is located; in S3, the ecological thresholds that affect the growth of aquatic organisms mainly include the flow velocity tolerance threshold, turbulence intensity tolerance threshold, sound wave and other factor tolerance thresholds, etc. The evaluation indicators of fish swimming ability mainly include induced flow velocity, preferred flow velocity and limit flow velocity. The maximum value of the limit flow velocity of different fish is the flow velocity tolerance threshold of fish; benthic organisms represented by crabs generally consider the maximum flow velocity of normal growth and habitat as the flow velocity tolerance threshold of benthic organisms. The maximum value of turbulence intensity of normal growth and habitat of benthic organisms is used as the turbulence intensity tolerance threshold of benthic organisms. The maximum value of sound intensity of normal life of fish is used as the sound wave threshold. Other factors affecting the growth and habitat of aquatic organisms are comprehensively determined based on the species of organisms and influencing factors of the waterway to be studied.

[0031] The scale design of the ecological waterway in this project is only explained by taking the flow velocity tolerance threshold as an example. Other indicators such as the turbulence intensity tolerance threshold, sound wave and other element tolerance thresholds can be determined by referring to the same method proposed in this invention. According to the analysis of the existing literature (Table 3 and Table 4), the limiting flow velocity of fish in inland waterways is 1.1m / s, and the limiting flow velocity of benthic organisms represented by crabs is 1.5m / s.

[0032] Table 3 Characteristic flow velocities of typical fish species in inland waterways

[0033]

[0034] Table 4 Characteristic flow velocities of typical benthic organisms in inland waterways

[0035] S4. Establish a ship model of the designed ship type, and combine the background flow velocity of the channel and the ship's navigation speed over the ground. Use the computational fluid dynamics model to carry out numerical simulation experiments, and calculate the hydrodynamic conditions of the ship's navigation waters in the downstream and upstream conditions respectively; In S4, computational fluid dynamics (CFD) models include Flow-3D, Fluent, CFX, Star-CCM+, Openfoam models, etc. Establish a ship model of the designed ship type, and combine the background flow velocity of the channel and the ship's navigation speed over the ground. Use the calibrated and verified computational fluid dynamics model software to carry out three-dimensional hydrodynamic numerical simulations, and calculate the hydrodynamic conditions of the ship's navigation waters in the downstream and upstream conditions (including flow velocity and turbulence intensity, etc.). According to the calibrated three-dimensional hydrodynamic numerical simulation calculation results of the ship's navigation, the free surface waveform diagram of the ship's navigation in the upstream condition is obtained (such as Figure 5 ).

[0036] S5. Based on the threshold value determined in step S3, the flow velocity and turbulence intensity influence ranges of each group calculated in step S4 are analyzed, and the maximum values ​​of the influence ranges in the width and depth directions of the channel outside the hull are taken as the ecologically rich width and ecologically rich depth of the ship's navigation, respectively. In S5, according to the ecological threshold value determined in S3, the ecological threshold contour lines are drawn in the flow velocity, turbulence and other factor result maps calculated in S4 to analyze the ecological influence range, and the maximum values ​​of the influence ranges in the width and depth directions of the channel outside the hull are taken as the ecologically rich width (d e ) and ecological richness depth (ΔH e ).

[0037] According to the limit flow velocity of benthic organisms, the velocity tolerance threshold of inland waterways is taken as 1.5 m / s, and the 1.5 m / s contour line is drawn in the velocity result map calculated by S4 (such as Figure 6 The maximum value d of the influence range in the channel width direction outside the hull is analyzed (shown by the thick red line in the middle). e and the maximum value of the influence range in the depth direction ΔH e , which is the ecologically rich width d of the ship's navigation e and ecological affluence depth ΔH e Since the navigable ships in both upstream and downstream directions of the two-way channel of this project are 2,000-ton ships, the ecologically rich width from the outer side of the upstream and downstream ships to the channel edge is equal, that is, d e1 =d e2 =16m. If the number of navigable ships going upstream and downstream is different, the ecologically rich width d from the outer side of the downstream ship to the edge of the channel needs to be calculated separately.e1 , ecologically rich width d from the outer side of the upstream ship to the edge of the channel e2 .

[0038] According to the ecological impact range analysis in the channel depth direction, the ecological rich depth ΔH e If the upstream and downstream navigable ships are different, it is necessary to calculate the ecological rich depth of the upstream and downstream ships respectively, and take the maximum value as the ecological rich depth ΔH e .

[0039] S6. Calculate the width and depth of the ecological channel based on the ecological richness width and ecological richness depth determined in S5. In S6, the width of the ecological channel B e and ecological channel depth H e Calculate according to the following formula. The calculation formula for the width of the ecological waterway is: B e =B Fd +B Fu +d e1 +d e2 +C B Fd =B Sd +L d sinβ B Fu =B Su +L u sinβ

[0040] Where: B e —Width of the straight double-line ecological waterway (m); B Fd —Width of downstream ship track (m); B Fu —Width of upstream ship track (m); d e1 —Ecologically rich width from the outer side of the downstream ship to the edge of the channel (m), determined according to the result of step 5; d e2 —Ecologically rich width from the outer side of the upstream ship to the edge of the channel (m), determined based on the result of step 5 Sd —Width of downstream ship (m); L d —downstream ship length (m); β—ship drift angle (°), 3° for Class I to Class V waterways, and 2° for Class V and Class VII waterways; B Su —Width of upstream ship (m); L u —The length of the upstream ship (m); C—The safe distance when ships meet each other (m), which is usually taken as the width of the upstream and downstream ships B Su and B Sd The maximum value of .

[0041] Ecological channel depth H e The calculation formula is: e=T+ΔH e

[0042] Where: H e —Ecological channel depth (m); T—ship design draft or operating draft (m); ΔH e —Ecological rich depth, determined according to the result of step 5, and the maximum value of the ecological rich depth of the downstream and upstream ships should be taken when calculating.

[0043] The width of ecological abundance d determined by S5 e and ecological affluence depth ΔH e , use the above calculation formula to calculate the width of the ecological channel B e =B Fd +B Fu +d e1 +d e2 +C=20.1+20.1+16+16+15.4=87.6m.

[0044] Ecological channel depth H e =T+ΔH e =2.6+0.6=3.2m.

[0045] S7. Compare the width and depth of the ecological channel with the design channel width and depth calculated using the formula recommended by the specification, and comprehensively determine the scale of the ecological channel. The values ​​are selected in three cases:

[0046] (1) Ecological channel width B e 、Ecological channel depth H e When the water depth and width of the design channel are less than or equal to the water depth of the design channel, the scale of the ecological channel shall be the scale of the design channel; (2) When the scale of the ecological waterway is larger than the scale of the design waterway but within 1.5 times of the scale of the design waterway, the scale of the waterway determined in step 6 shall be taken as the scale of the ecological waterway; (3) When the scale of the ecological channel is larger than 1.5 times the scale of the design channel, S4 to S7 can be repeated by adjusting the ship speed, adjusting the background flow velocity, etc., until the scale of the ecological channel that reduces the navigation efficiency but meets the ecological requirements is obtained.

[0047] The width of the ecological channel B calculated based on S6 e The design channel width in Table 2 is 70m, and the width of the ecological channel is 1.25 times (within 1.5 times) the design channel width; the depth of the ecological channel H e The width of the ecological channel is 3.2 m. The depth of the design channel in Table 2 is 3.0 m. The depth of the ecological channel is 1.07 times (within 1.5 times) the depth of the design channel. According to the judgment condition (2) of S7, the width of the ecological channel B e and ecological channel depth H eare larger than the design channel size but within 1.5 times of it. Therefore, the width of the ecological channel B e and ecological channel depth H e The ecological waterway scale values ​​calculated by S6 are 87.6m and 3.2m respectively.

[0048] If the judgment condition (3) in S7 occurs, it is necessary to adjust the ship speed, adjust the background flow velocity, etc., and repeat S4 to S7 until the ecological waterway scale that meets the ecological requirements is obtained.

[0049] The above-mentioned related explanations and descriptions of the embodiments are for the convenience of those skilled in the art to understand and apply the present invention. It is obvious that those familiar with the art can easily make various modifications to these contents and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above-mentioned related explanations and descriptions of the embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for designing the scale of an inland ecological waterway, characterized in that: The steps include: S1. Determine the design ship type and control ship type according to the waterway operation requirements, calculate the design waterway scale, and select the ship's navigation speed over the ground; S2. Analyze and calculate the background flow characteristics of the channel under different guarantee rates according to the water flow characteristics of the river where the channel is located, wherein the background flow characteristics of the channel include the background flow velocity and the background flow direction of the channel; S3. Analyze the ecological thresholds of fish, benthic organisms, and typical aquatic organisms in the project area; S4. Establish a ship model of the designed ship type, and combine the background flow velocity of the channel and the ship's navigation speed over the ground. Use the computational fluid dynamics model to carry out numerical simulation experiments to calculate the hydrodynamic conditions of the ship's navigation waters under downstream and upstream conditions respectively; S5. Based on the threshold value determined in step S3, the velocity and turbulence intensity influence ranges of each group calculated in step S4 are analyzed, and the maximum values ​​of the influence ranges in the width and depth directions of the channel outside the hull are taken as the ecologically rich width and ecologically rich depth of the ship's navigation, respectively; S6, calculating the ecological channel width and the ecological channel depth based on the ecological rich width and the ecological rich depth determined in step S5; S7. Compare the width and depth of the ecological channel with the design channel width and depth calculated using the formula recommended by the specification, and comprehensively determine the scale of the ecological channel.

2. The inland river ecological waterway scale design method according to claim 1 is characterized in that: The hydrodynamic conditions of the ship's navigation waters include hydrodynamic flow velocity and hydrodynamic turbulence intensity indicators.

3. The inland river ecological waterway scale design method according to claim 1 is characterized in that: In step S1, the design of representative ship type and control ship type scale is determined according to the "Inland River Navigation Standard", "Yangtze River Main Line Navigation Standard" and "Canal Navigation Standard"; the ship's navigation speed over the ground is determined according to the relevant requirements of navigation management and ship navigation experience; In step S2, the water flow velocity and flow direction data of the river where the waterway is located in different seasons and time periods are collected, the flow velocity distribution of the waterway to be studied is analyzed by frequency, the flow velocity at different guarantee rates of 25%, 50%, 75% and 90% is calculated, and the background flow characteristics of the waterway used in the scale design of the ecological waterway are comprehensively determined.

4. The inland river ecological waterway scale design method according to claim 1 is characterized in that: In step S3, the ecological thresholds that affect the growth of aquatic organisms mainly include flow velocity tolerance threshold, turbulence intensity tolerance threshold, and sound wave and element tolerance threshold.

5. The inland river ecological waterway scale design method according to claim 1 is characterized in that: In step S4, computational fluid dynamics models including Flow-3D, Fluent, CFX, Star-CCM+, and Openfoam models are used to establish a ship model of the designed ship type, combine the channel background flow velocity and the ship's navigation speed over the ground, and use calibrated and verified computational fluid dynamics model software to carry out three-dimensional hydrodynamic numerical simulation.

6. The inland river ecological waterway scale design method according to claim 1 is characterized in that: In step S5, according to the ecological threshold determined in step S3, ecological threshold contour lines are drawn in the velocity, turbulence and element results diagram calculated in step S4 to analyze the ecological impact range, and the maximum value of the impact range in the width and depth direction of the channel outside the hull is taken as the ecological rich width and ecological rich depth of the ship's navigation.

7. The inland river ecological waterway scale design method according to claim 1 is characterized in that: In step S6, the calculation formula of the ecological waterway width is: B e =B Fd +B Fu +d e1 +d e2 +C B Fd =B Sd +L d sinβ B Fu =B Su +L u sinβ Among them, B e B is the width of the straight double-line ecological channel; Fd B is the width of the downstream ship track; Fu is the width of the upstream ship track; d e1 is the ecologically rich width from the outer side of the downstream ship to the edge of the channel, and is determined according to the calculation result of step S5; d e2 is the ecologically rich width from the outer side of the upstream ship to the edge of the channel, determined according to the calculation result of step S5; B Sd L is the width of the downstream ship; d is the length of the downstream ship; β is the ship's drift angle, of which 3° is acceptable for Class I to Class V waterways, and 2° for Class V and Class VII waterways; B Su is the width of the upstream ship; L u is the length of the upstream ship; C is the safe distance when ships meet each other, taking the width of the upstream and downstream ships B Su and B Sd The maximum value of The calculation formula for the ecological channel depth is: e =T+ΔH e Where: H e is the depth of the ecological channel; T is the ship's design draft or operating draft; ΔH e is the ecological rich depth, which is determined according to the calculation result of step S5, and the maximum value of the ecological rich depth of the downstream and upstream ships should be taken during the calculation.

8. The inland river ecological waterway scale design method according to claim 1 is characterized in that: In step S7, the formula recommended by the specification mainly refers to the waterway dimension calculation formula specified in the "Inland Waterway Navigation Standards", "Canal Navigation Standards", "Waterway Engineering Design Standards" and the Ministry of Transport specifications.

9. The inland river ecological waterway scale design method according to claim 1 is characterized in that: In step S7, When the width Be and depth He of the ecological channel are less than or equal to the width and depth of the designed channel, the scale of the ecological channel shall be the scale of the designed channel; When the scale of the ecological waterway is larger than the scale of the designed waterway but within 1.5 times of the scale of the designed waterway, the scale of the waterway determined in step S6 is taken as the scale of the ecological waterway; When the scale of the ecological channel is more than 1.5 times the scale of the design channel, the ship speed and the background flow velocity can be adjusted, and steps S4 to S7 can be repeated until the scale of the ecological channel that reduces the navigation efficiency but meets the ecological requirements is obtained.

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