A design method for partitioned flow of a porous barrage

Abstract

The present application belongs to the technical field of river barrage design, and particularly relates to a method for partitioned flow design of a multi-hole river barrage, which comprises the following steps: obtaining characteristic hydrological parameters and structural parameters of the river barrage, and obtaining a fitted water level-flow relationship curve of the river barrage according to historical water level and flow data of the river barrage; calculating a selected opening water level and a corresponding flow through the river barrage based on the characteristic hydrological parameters, the structural parameters and the water level-flow relationship curve of the river barrage; and calculating and determining the number of the first opening holes and the number of the second opening holes based on the characteristic hydrological parameters, the structural parameters and the flow through the river barrage when the second opening holes are opened. According to the characteristic hydrological parameters and the structural parameters of different river barrages, the present application can quickly and simply design the partitioned flow of the multi-hole river barrage, determine the number of the first and second opening holes, and use the number as the basis for the design of the downstream energy dissipation and scour prevention and the development of the partitioned multi-hole barrage operation scheme.

Description

Technical Field

[0001] This invention belongs to the field of river dam design technology, specifically relating to a multi-hole river dam zone flow design method. Background Technology

[0002] In engineering practice, multi-hole dams have been widely adopted in coastal river network areas such as Guangdong, Fujian, and Jiangsu to achieve comprehensive functions including flood control, drainage, tide control, water supply, and power generation. The flow area of ​​the dam is divided into zones for energy dissipation and scour prevention by setting up piers or guide walls, which not only helps optimize project investment but also simplifies operation and scheduling logic.

[0003] Currently, the design of river dams mainly follows the industry standard "Design Code for River Dams" (SL 265-2016). Its design concept is to set up piers or guide walls as needed to carry out zoned energy dissipation and scour prevention. It is clear that this approach is beneficial to improving the downstream flow pattern, but it does not further clarify the specific conditions, technical advantages and design methods for zoning, and lacks systematic guidance.

[0004] Given that existing dam designs lack a systematic approach to zonal flow control for multi-gate dams, there is an urgent need to establish a zonal flow control design method based on the characteristic parameters of dams. This method should systematically determine the number of opening gates in advance and the number of opening gates in the later stages based on hydrological and structural parameters, providing a theoretical basis and engineering guidance for energy dissipation and scour prevention design and zonal scheduling. Summary of the Invention

[0005] The purpose of this invention is to provide a method for designing the zonal flow passage of a multi-hole dam, which can quickly and easily design the zonal flow passage of a multi-hole dam based on the characteristic hydrological parameters and structural parameters of different dams, and determine the number of openings in sequence, thereby serving as the basis for the design of energy dissipation and scour prevention downstream of the dam and the formulation of the zonal multi-hole dam scheduling and operation scheme.

[0006] The specific technical solution adopted by this invention is as follows: A method for designing zoned flow passage in a multi-hole river dam includes the following steps: Obtain characteristic hydrological parameters and structural parameters of the dam, and derive the downstream water level-discharge relationship curve based on historical downstream water level and flow data of the multi-hole dam. Based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the water level-discharge relationship curve downstream of the dam, the selected dam opening water level and the corresponding discharge flow are calculated. Based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the gate is opened later, the number of gates to be opened first and the number of gates to be opened later are calculated and determined. The order of opening holes, the order of opening holes, and the arrangement of partition walls are determined.

[0007] As an optional solution, the characteristic hydrological parameters and structural parameters of the dam include the upstream water level. , weir crest elevation Total number of sluice gates Single hole width ; At the same time, the water level downstream of the sluice gate was set as The flow rate downstream of the gate is The downstream water level-flow curve is used to reflect the relationship between the downstream water level and flow rate under the overflow state of the multi-hole dam.

[0008] As an optional approach, the calculation of the selected gate opening water level and corresponding flow rate based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the downstream water level-flow relationship curve includes the following steps: The water level after the gate is opened is set to be... Based on the characteristic hydrological parameters and structural parameters of the dam, the opening water level is calculated and selected as follows: (1) Formula (1) At this point, the characteristic hydrological parameters and structural parameters of the dam are substituted into the right side of the inequality in the above formula (1) for calculation, thereby selecting... ; At the same time, the corresponding flow rate through the dam when the gate is opened is obtained by interpolation based on the downstream water level-flow relationship curve. .

[0009] As an optional approach, the calculation and determination of the number of openings before and after the gate is opened, based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the gate is opened later, includes the following steps: Set the number of holes to be opened first. The number of openings to be opened first is calculated based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the later openings are opened, as shown in formulas (2) and (3) below: Formula (2) Formula (3) in, This indicates the minimum total width of the orifice for flow. At this point, the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the gate is opened are substituted into the above formula (2) for calculation. ,Will Substituting the calculation result into formula (3) yields the result. The value; At the same time, the actual number of openings of the multi-hole dam is set to be greater than the calculated number of openings, so as to ensure that the dam has sufficient flood discharge space when the flow is flowing and reduce the impact of upstream floods on the multi-hole dam. Set the number of rear opening holes to The calculation is performed using the following formula (4): Formula (4) Substitute the structural parameters of the dam and the calculation results of formula (3) into formula (4) to calculate. The value of .

[0010] As an optional approach, the pre-opening, post-opening, and partition wall arrangement includes the following steps: The first opening is centrally located in the river channel, while the second opening is located on both sides of the dam. A stilling basin is set up in the area downstream of the first opening, while no stilling basin is set up in the area downstream of the second opening. Alternatively, a stilling basin may be set up in the area downstream of the corresponding gate opening in the river channel. A partition wall may be set up between the stilling basins to physically separate the water flows from different gate openings, so as to avoid the water flows from interfering with each other, colliding and forming disordered vortices in the stilling basin, thereby improving the energy dissipation efficiency.

[0011] As an alternative, the pre-opening and post-opening areas are arranged alternately, and at least one of the pre-opening and post-opening areas is adjacent to the riverbank. Meanwhile, the number of the first-opening holes and the number of the second-opening holes are equal, or the number of the first-opening holes and the number of the second-opening holes are unequal.

[0012] As an alternative, the characteristic hydrological parameters of the dam can be measured by setting up permanent water gauges in stable river sections upstream and downstream of the dam chamber; Alternatively, measurements can be taken by installing automatic water level gauges in stable river sections upstream and downstream of the sluice chamber; Meanwhile, the flow velocity at each point in the standard cross-section before and after the gate was measured using a Doppler velocity profiler. Alternatively, the flow velocity at each point in the standard cross-section before and after the gate can be measured using a rotor-type flow meter.

[0013] As an optional solution, the total number of gate openings N, the width of a single gate b0, and the weir crest elevation H of the dam are... 堰顶 The weir crest elevation H is set according to the existing conditions of the river channel. 堰顶 The elevation of the riverbed at the location of the sluice gate is set.

[0014] As an alternative, after the design method is used to design the river dam, the first and second opening holes remain normally closed when there is no flood passing through, or the first opening hole is partially opened to only meet the ecological flow discharge.

[0015] The technical effects achieved by this invention are as follows: This invention enables rapid and convenient design of multi-hole dam zonal flow passage using known hydrological and structural parameters of dams, determining the zonal sections for opening the dams first and later. A stilling basin is installed downstream of the first-opening dam, while a stilling basin may not be installed downstream of the second-opening dam. This simplifies energy dissipation calculations, saves on engineering investment, and facilitates operation and management.

[0016] The multi-hole dam zoning flow design method provided by this invention is applicable to large-flow, multi-hole dams with normally closed gates for water storage built in coastal areas and other regions, and can be used to promote the zoning flow design of this type of dam. Attached Figure Description

[0017] Figure 1 This is a flowchart of the partitioned overcurrent design method of the present invention; Figure 2 This is a schematic diagram of the design parameters for the partitioned overcurrent design method of the present invention; Figure 3 This is a schematic diagram of the water level-flow relationship curve downstream of the sluice gate in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the water level-flow relationship curve downstream of the sluice gate in Embodiment 2 of the present invention. Detailed Implementation

[0018] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0019] Example 1: like Figures 1-3 As shown, a multi-hole river dam zone flow design method includes the following steps: First, based on the specific circumstances of the dam project, we obtain the characteristic hydrological parameters and structural parameters of the dam. Taking the first multi-span dam as an example, for instance... Figure 3 The design parameters shown, along with the characteristic hydrological parameters and structural parameters of the dam, are as follows: Upstream water level , weir crest elevation (Set according to the riverbed elevation at the dam site), total number of dam openings (Set according to the location of the dam, the width of the river channel, and the width of each individual sluice gate) Single sluice gate width (Set according to requirements); Among them, the characteristic hydrological parameters of the dam are measured by setting up permanent water gauges or installing automatic water level gauges in the stable river sections upstream and downstream of the dam chamber. At the same time, the flow velocity at each point of the standard cross-section upstream or downstream of the dam is measured by using a Doppler current profiler or a rotor current meter, and the flow rate is calculated by integrating the cross-sectional area. The structural parameters of the dam include the total number of gates N, the width of a single gate b0, and the weir crest elevation H. 堰顶 The settings are based on the current conditions of the river channel. Based on the characteristic hydrological parameters and structural parameters of the first multi-hole dam, its downstream water level was set as follows: The flow rate downstream of the gate is The downstream water level and flow rate data of the first multi-hole dam were obtained by calculating the characteristic hydrological parameters and recorded in Table 1 below; Table 1. Statistical data on downstream water level and flow rate of the first multi-hole dam. At this point, the downstream water level and flow rate data of the first multi-hole dam in Table 1 are used to plot the downstream water level and flow rate relationship curve shown in the figure. ~ The curve is used to intuitively reflect the positive correlation between the water level downstream of the first multi-hole dam and its downstream flow rate under the flow conditions, and serves as the data basis for calculating the number of openings before and after the first multi-hole dam. Secondly, the water level for opening the gate after the sluice gate is set to be... Based on the characteristic hydrological parameters and structural parameters of the dam, the opening water level after the gate is opened is calculated and selected. The calculation relationship is as follows: (1) Formula (1) Therefore, the characteristic hydrological parameters and structural parameters of the dam are substituted into the right side of the inequality in the above formula (1) for calculation. Therefore, this embodiment selects ; At the same time, the corresponding flow rate through the dam when the gate is opened is obtained by interpolation based on the downstream water level-flow relationship curve. ; Then, set the number of holes to be opened first. The number of gates to be opened first is calculated based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the gate is opened later. The calculation relationships are as follows: Formula (2) and Formula (3): Formula (2) Formula (3) in, This indicates the minimum total width of the orifice for flow. Therefore, the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the gate is opened are substituted into the above formula (2) for calculation: At this point, substitute the above calculation results into formula (3) for calculation: In this embodiment, to allow for a certain degree of margin, the actual number of openings in the first multi-hole dam is greater than the calculated number. This ensures that the dam has sufficient flood discharge space during overflow, reducing the impact of upstream floodwaters on the first multi-hole dam. Therefore, the actual number of openings in the first multi-hole dam is set to 13, and the number of openings to be opened later is also set to... The calculation is performed using the following formula (4): Formula (4) Substitute the structural parameters of the dam and the calculation results of formula (3) into formula (4) to obtain the calculation results. hole; Finally, the arrangement of the pre- and post-opening holes and the partition walls is carried out. In this embodiment, 13 pre-opening holes are arranged in the center of the river channel, and 7 post-opening holes are arranged on both sides of the dam. The area of ​​the river channel downstream of the 13 pre-opening holes is equipped with a stilling pool according to the energy dissipation requirements, while the area of ​​the river channel downstream of the post-opening holes may not be equipped with a stilling pool, so as to reduce the construction cost of the dam.

[0020] It should be noted that the opening holes are distributed alternately, and the opening hole can be set at the edge of the river channel, or the opening hole can be set at both the edge of the river channel and the center; the opening hole can be set at the edge of the river channel, or the opening hole can be set at both the edge of the river channel and the center.

[0021] The pre-opening and post-opening areas are arranged alternately, and at least one of the pre-opening and post-opening areas is adjacent to the riverbank. At the same time, the number of the first-opening hole area and the second-opening hole area are equal, or the number of the first-opening hole area and the second-opening hole area are unequal.

[0022] Assume that stilling basins are set up in the areas downstream of the first and second gates of the river channel, and partition walls are set up between the stilling basins. The partition walls can physically separate the water flows from different gates, preventing the water flows from interfering with each other, colliding, or forming disordered vortices in the stilling basins, thereby improving the downstream flow pattern and increasing the energy dissipation efficiency. The partition walls can also limit the lateral diffusion of the hydraulic jump, so that the hydraulic jump occurs more stably within the design range of the stilling basin, thereby improving the energy dissipation effect.

[0023] Example 2: like Figure 1 and Figure 4As shown, a multi-hole dam zone flow design method is basically the same as that in Embodiment 2. The similarities can be found in Embodiment 2, but the difference lies in the inclusion of the following steps: First, based on the specific circumstances of the dam project, the characteristic hydrological parameters and structural parameters of the dam are obtained. Taking the second multi-gate dam as an example, its characteristic hydrological parameters and structural parameters are as follows: Upstream water level , weir crest elevation Total number of sluice gates Single hole width ; Collect the downstream water level and flow rate data of the second multi-hole dam at a preset period, and record them in Table 2 below; Table 2. Statistical data on downstream water level and flow rate of the second multi-hole dam. At this point, the downstream water level and flow rate data of the second multi-hole dam in Table 2 are used to plot the downstream water level and flow rate relationship curve shown in the figure. ~ The curve is used to intuitively reflect the positive correlation between the water level downstream of the second multi-hole dam and its downstream flow rate under the flow conditions, and serves as the data basis for calculating the number of openings before and after the multi-hole dam. Secondly, based on the characteristic hydrological parameters and structural parameters of the dam, the opening water level after the gate is selected is calculated. The characteristic hydrological parameters and structural parameters of the dam are then substituted into the right side of the inequality in formula (1) of Example 2 for calculation. Therefore, this embodiment selects ; At the same time, the flow rate through the dam when the second multi-hole dam is opened is obtained by interpolation based on the water level-flow relationship curve. Then, based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the second opening is opened, the number of openings of the second multi-hole dam is calculated. The characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the second opening is opened are substituted into formula (2) of Example 2 for calculation: At this point, substitute the above calculation results into formula (3) of Example 2 for calculation: In this embodiment, to reserve a certain degree of margin, the actual number of opening holes of the second multi-hole dam is greater than the calculated number of opening holes, so as to ensure that the second multi-hole dam has sufficient flood discharge space during overflow, thereby reducing the impact of upstream floods on the second multi-hole dam. The actual number of opening holes of the second multi-hole dam is set to 10. The dam structure parameters of the second multi-hole dam and the calculation results of formula (3) are substituted into formula (4) for calculation to obtain the calculation results. hole; Finally, the arrangement of the first and last opening holes and the partition wall of the second multi-hole dam is carried out. In this embodiment, 10 first opening holes are arranged in the center of the river channel, and 11 last opening holes are arranged on both sides of the second multi-hole dam. The area of ​​the river channel downstream of the 10 first opening holes is equipped with a stilling pool according to the energy dissipation needs, while the area of ​​the river channel downstream of the last opening holes may not be equipped with a stilling pool, so as to reduce the construction cost of the dam.

[0024] In summary, this invention enables rapid and simple design of multi-hole dam zonal flow passage using known hydrological and structural parameters of dams, determining the zonal sections for opening the dams first and later. A stilling basin is installed downstream of the first-opening dam, while a stilling basin may not be installed downstream of the second-opening dam. This simplifies energy dissipation calculations, saves on engineering investment, and facilitates operation and management, providing a theoretical basis for the construction of multi-hole dams.

[0025] It should be noted that the multi-hole dam targeted by this invention remains in a normally closed state when there is no flood passing through. That is, after the water level upstream of the multi-hole dam drops to the safe height limit, the first and second opening holes can be closed to restore the multi-hole dam to its normal closed state, or the first opening hole can be partially opened to only meet the ecological flow discharge.

[0026] In summary, this invention enables rapid and convenient zonal flow design of multi-gate dams based on the characteristic hydrological and structural parameters of different dams, determining the number of gates to be opened first and last, thus serving as the basis for the energy dissipation and scour prevention design downstream of the dam and the formulation of zonal multi-gate scheduling and operation schemes.

[0027] The above description is merely an optional embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A method for designing zoned flow passage in a multi-hole river dam, characterized in that, Includes the following steps: Obtain characteristic hydrological parameters and structural parameters of the dam, and derive the downstream water level-discharge relationship curve based on historical downstream water level and flow data of the multi-hole dam. Based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the water level-discharge relationship curve downstream of the dam, the selected dam opening water level and the corresponding discharge flow are calculated. Based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the gate is opened later, the number of gates to be opened first and the number of gates to be opened later are calculated and determined. The order of opening holes, the order of opening holes, and the arrangement of partition walls are determined.

2. The multi-hole dam zone flow design method according to claim 1, characterized in that: The characteristic hydrological parameters and structural parameters of the dam include the upstream water level. , weir crest elevation Total number of sluice gates Single hole width ; At the same time, the water level downstream of the sluice gate was set as The flow rate downstream of the gate is The downstream water level-flow curve is used to reflect the relationship between the downstream water level and flow rate under the overflow state of the multi-hole dam.

3. The multi-hole river dam zone flow design method according to claim 2, characterized in that, The calculation and selection of the gate opening water level and corresponding flow rate based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the downstream water level-discharge relationship curve includes the following steps: The water level after the gate is opened is set to be... Based on the characteristic hydrological parameters and structural parameters of the dam, the opening water level is calculated and selected as follows: (1) Official (1) At this point, the characteristic hydrological parameters and structural parameters of the dam are substituted into the right side of the inequality in the above formula (1) for calculation, thereby selecting... ; At the same time, the corresponding flow rate through the dam when the gate is opened is obtained by interpolation based on the downstream water level-flow relationship curve. .

4. The multi-hole dam zone flow design method according to claim 2, characterized in that, The process of calculating and determining the number of openings before and after the dam, based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the dam is opened later, includes the following steps: Set the number of holes to be opened first. The number of openings to be opened first is calculated based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the later openings are opened, as shown in formulas (2) and (3) below: Official (2) Official (3) in, This indicates the minimum total width of the orifice for flow. At this point, the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the gate is opened are substituted into the above formula (2) for calculation. ,Will Substituting the calculation result into formula (3) yields the result. The value of .

5. The multi-hole dam zone flow design method according to claim 1, characterized in that, The calculation and determination of the number of openings first and last based on the characteristic hydrological parameters of the dam, the structural parameters of the dam, and the flow rate through the dam when the gate is opened later also includes the following steps: The actual number of openings of the multi-hole dam is set to be greater than the calculated number of openings, so as to ensure that the dam has sufficient flood discharge space when the flow is flowing and reduce the impact of upstream floods on the multi-hole dam. Set the number of rear opening holes to The calculation is performed using the following formula (4): Official (4) Substitute the structural parameters of the dam and the calculation results of formula (3) into formula (4) to calculate. The value of .

6. The multi-hole river dam zone flow design method according to claim 1, characterized in that, The process of pre-opening holes, post-opening holes, and arranging partition walls includes the following steps: The first and second opening holes are arranged in the river channel. A stilling basin is set up in the area of ​​the river channel downstream of the first opening hole, while no stilling basin is set up in the area of ​​the river channel downstream of the second opening hole. A partition wall is set up between the areas of the first and second opening holes downstream of the river channel. Alternatively, a stilling basin may be set up in the area downstream of the later-opening gate in the river channel. A partition wall is set between the area of ​​this stilling basin and the area of ​​the stilling basin downstream of the earlier-opening gate. The partition wall is used to physically separate the water flow from different gates, so as to avoid the water flow from interfering with each other, colliding and forming disordered vortices in the stilling basin, thereby improving the energy dissipation efficiency.

7. The multi-hole dam zone flow design method according to claim 6, characterized in that: The pre-opening and post-opening areas are arranged alternately, and at least one of the pre-opening and post-opening areas is adjacent to the riverbank. Meanwhile, the number of the first-opening hole region and the second-opening hole region are equal, or the number of the first-opening hole region and the second-opening hole region are unequal.

8. The multi-hole dam zone flow design method according to claim 1, characterized in that: The characteristic hydrological parameters of the dam are measured by setting up permanent water gauges in stable river sections upstream and downstream of the dam chamber. Alternatively, measurements can be taken by installing automatic water level gauges in stable river sections upstream and downstream of the sluice chamber; Meanwhile, the flow velocity at each point in the standard cross-section before and after the gate was measured using a Doppler velocity profiler. Alternatively, the flow velocity at each point in the standard cross-section before and after the gate can be measured using a rotor-type flow meter.

9. The multi-hole dam zone flow design method according to claim 1, characterized in that: The total number of gate openings N, the width of a single gate b0, and the weir crest elevation H of the dam are specified. 堰顶 The weir crest elevation H is set according to the existing conditions of the river channel. 堰顶 The elevation of the riverbed at the location of the sluice gate is set.

10. The multi-hole dam zone flow design method according to claim 1, characterized in that: After the design method is used to design the river dam, when there is no flood passing through, the first opening hole and the second opening hole remain in a normally closed state, or the first opening hole is partially opened to meet the ecological flow discharge.

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