A flood discharge gate wide tail pier and a design method thereof

Abstract

The present application relates to the field of flood discharge, in particular to a kind of flood discharge lock wide tail pier and design method thereof, design method includes the following steps: S1: establishing flood discharge lock single hole mathematical model;Determine the structural design parameters of wide tail pier, including tail pier type, contraction front orifice width, pier tail corner, contraction ratio, outlet width, contraction section length and pier top elevation;S2: for structural design parameters combination, form multiple wide tail pier design scheme, and each design scheme is respectively input mathematical model calculation, obtain calculation result;S3: with impact support hinge risk value k as judging condition to determine the optimal design scheme of wide tail pier, k=f (water jump jump head position, jump head water depth, lock chamber maximum bottom flow velocity, discharge flow, lock chamber water surface line), f is function.The present application establishes flood discharge lock single hole mathematical model, obtains the calculation result of various design schemes quickly, with impact support hinge risk value k as judging condition, can quickly and accurately determine the optimal structure form of wide tail pier.

Description

Technical Field

[0001] This invention relates to the field of flood discharge, and in particular to a wide tail pier for a flood discharge gate and its design method. Background Technology

[0002] A floodgate is a gate used to discharge floodwaters and regulate the water level of a reservoir. It releases excess water when the water level is too high, ensuring the safety of the reservoir or river, effectively preventing floods, and avoiding significant losses of life and property. At the same time, floodgates can also regulate water levels, maintain the stability of water sources and the cleanliness of water quality, and improve production efficiency and agricultural productivity.

[0003] Low-head riverbed-type sluice gates have large discharge volumes and significant downstream submersion. Hydraulic jumps may occur in the steep slope section of the gate chamber, with the jump head located close to the gate hinges. The surface water jets may impact the gate hinges, potentially affecting the stability of the hinge structure.

[0004] A wide-tail pier involves widening the tail of the gate pier, narrowing the gate chamber outlet, and causing the water flow behind the pier to contract laterally, forming a narrow and high "1"-shaped three-dimensional contraction jet to enhance energy dissipation, reduce erosion, and prevent corrosion. It utilizes the wide-tail pier to create a contraction jet at the weir crest, forming a violently aerated three-dimensional hydraulic jump in the stilling basin, thereby significantly increasing the energy dissipation rate. By modifying the structural form of the wide-tail pier, it helps the water flow transition more smoothly, reducing water jet jumping and splashing, thus lowering the risk of impact from the surface water jet on the gate hinges. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a wide tail pier for a flood discharge gate and its design method.

[0006] In a first aspect, the present invention provides a design method for a wide tail pier of a flood discharge gate, comprising the following steps:

[0007] S1: Establish a mathematical model of a single outlet of the floodgate; determine the structural design parameters of the wide tail pier, including the tail pier type, the width of the outlet before contraction, the tail pier angle, the contraction ratio, the outlet width, the length of the contraction section, and the top elevation of the pier;

[0008] S2: Combine the structural design parameters to form multiple wide tail pier design schemes, and input each design scheme into the mathematical model for calculation to obtain the calculation results;

[0009] S3: The optimal design scheme of the wide tail pier is determined by using the impact hinge risk value k as the judgment condition. k = f(position of the water jump, water depth of the jump, maximum bottom velocity of the gate chamber, discharge flow rate, water surface line of the gate chamber), where f is a function.

[0010] This invention provides a design method for a wide tail pier of a flood discharge gate. By establishing a mathematical model of a single opening of the flood discharge gate, the law of hydraulic jump can be studied, and the calculation results of various design schemes can be obtained quickly. Through further evaluation of the calculation results, the optimal design scheme of the wide tail pier is determined by using the impact hinge risk value k as a judgment condition. The optimal structural form of the wide tail pier can be determined quickly and accurately.

[0011] Preferably, in step S3, the expression for the impact hinge risk value k is as follows:

[0012] k = n1f1 (position of the water jump) + n2f2 (depth of the water jump) + n3f3 (maximum near-bottom velocity of the lock chamber)

[0013] +n4f4 (discharge flow) +n5f5 (water level in the gate chamber);

[0014] In the formula, f1, f2, f3, f4, and f5 are functions, n1, n2, n3, n4, and n5 are coefficients, and n1+n2+n3+n4+n5=1.

[0015] Preferably, in S3, n1≥n2>n3≥n4≥n5.

[0016] Preferably, in S1, the model range for establishing the mathematical model of a single outlet of the flood discharge gate is from l1m above the dam to l2m below the dam, where l2>l1.

[0017] Preferably, in S1, when establishing the mathematical model of a single outlet of the flood discharge gate, the upstream boundary adopts the water level boundary, and the downstream boundary adopts the water level boundary.

[0018] Preferably, in S1, the tail pier type includes rectangular, Y-shaped, and X-shaped.

[0019] Preferably, in step S1, the structural design parameters further include whether the bottom is open and the bottom open height.

[0020] Preferably, the numerical value of each of the structural design parameters is determined to be within a preliminary range based on theoretical calculations.

[0021] Preferably, the numerical value of each of the structural design parameters varies uniformly.

[0022] In a second aspect, the present invention provides a floodgate, which is designed using any of the floodgate wide tail pier design methods described above.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention provides a wide-tail pier for a flood discharge gate and its design method. By establishing a mathematical model of a single gate, the hydraulic jump variation law can be studied, and the calculation results of various design schemes can be quickly obtained. Through further evaluation of the calculation results, the optimal design scheme of the wide-tail pier is determined using the impact hinge risk value k as a judgment condition. This allows for the rapid and accurate determination of the optimal structural form of the wide-tail pier. The optimized wide-tail pier of the flood discharge gate can effectively reduce the risk of surface water splash impacting the gate hinges, ensuring the safe operation of the flood discharge gate. Attached Figure Description

[0025] Figure 1 This is a plan view of the spillway structure.

[0026] Figure 2 This is a longitudinal section view of the floodgate.

[0027] Figure 3 This is a schematic diagram illustrating the risk of water droplets on the surface of the water jet impacting the gate hinges.

[0028] Figure 4 This is a schematic diagram of the mathematical model of a single outlet of a floodgate.

[0029] Figure 5 This is a boundary condition diagram for the mathematical model of the flood discharge gate.

[0030] Figure 6 This is a schematic diagram of the shape and structure of the wide tail pier.

[0031] Figure 7 Plan view of the wide tail pier (unit: m).

[0032] Figure 8 This is a schematic diagram of the flow field in the gate chamber of the wide-tail pier scheme.

[0033] Figure 9 The waterline along the route of the wide tail pier scheme.

[0034] Figure 10 Recommended wide-tail pier body shape parameters diagram (unit: m). Detailed Implementation

[0035] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0036] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0037] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0038] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing between identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0039] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0040] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0041] Example 1

[0042] The spillway structure of a certain hub mainly consists of 7 floodgates and 1 bottom outlet. The dam is 122m long and the crest elevation is 17.50m. The plan layout and longitudinal section of the spillway structure are shown below. Figure 1-2 As shown.

[0043] The seven-gate spillway is located in the main channel, with a single gate having a net width of 13.0m and a total frontal width of 116.0m. It employs a segmented pier design, with the left pier being 2.0m thick, the middle pier 3.5m thick, and the right pier 2.0m thick, resulting in a single-gate span width of 16.50m. The spillway crest elevation is 17.50m, the weir crest elevation is 1.00m, and the gate chamber is 35.0m long in the direction of water flow. From upstream to downstream, a flat inspection gate and an arc-shaped working gate are sequentially installed. The inspection gate is opened and closed using a mobile gantry crane on the dam crest, while the working gate is opened and closed using a hydraulic hoist. A 4.8m wide traffic bridge is located upstream of the gate crest, with a bridge crest elevation of 17.50m. Two gantry crane track beams are located adjacent to the traffic bridge, and a cable and oil pipeline box girder is located downstream. The spillway weir is a broad-crested weir, with a crest elevation of 1.00m for all sections. After the floodgate, it connects to the sea via a 1:4 slope. The sea is 100m long and has a rock-filled anti-scour trough at the end.

[0044] This dam is a low-head riverbed dam with a large flood discharge and significant downstream submersion. Under the check conditions, the hydraulic jump occurs on a steep slope of the dam chamber, with the jump head located close to the gate hinges. The surface water jet poses a risk of impacting the gate hinges, potentially negatively affecting their stability. Figure 3 As shown.

[0045] Consider optimizing the gate chamber's structure to shift the hydraulic jump location downstream, thereby reducing the water depth at the hinge location. Specifically:

[0046] A design method for a wide tail pier of a flood discharge gate includes the following steps:

[0047] S1: Establish a mathematical model of a single outlet of the floodgate, determine the boundary conditions and initial water flow of the mathematical model, and perform numerical simulation calculations.

[0048] Mathematical model of a single spillway gate as follows Figure 4 As shown. The model's research range is from 10m upstream of the dam to 120m downstream. The upstream boundary uses a water level boundary with a water level set at 15.17m, and the downstream boundary uses a water level boundary with a water level set at 11.74m. The boundary conditions and initial flow settings for the mathematical model are shown below. Figure 5 .

[0049] The structural design parameters for the wide-tail pier are determined, including pier type, orifice width before contraction, pier tail angle, contraction ratio, outlet width, contraction section length, and pier top elevation. More preferably, the structural design parameters also include whether the bottom is open and the height of the open bottom.

[0050] S2: Combine the structural design parameters to form multiple wide tail pier design schemes, and input each design scheme into the mathematical model for calculation to obtain the calculation results.

[0051] The numerical values ​​of each structural design parameter can be determined based on theoretical calculations to establish a preliminary range. For example, the body shape parameters of wide-tail piers in some existing low-head water projects are shown in Table 1 and... Figure 6 As shown.

[0052] Table 1. Body shape parameters of wide-tail piers in typical existing projects

[0053]

[0054] In the table, the shrinkage ratio ε = B / B; the initial inflection point position parameter = X / Hd.

[0055] Based on the layout characteristics of a certain hub's floodgate and referring to relevant engineering experience, the wide-tail pier body shape was designed. Two initial turning points for the wide-tail piers were initially selected: (1) According to the actual layout of the project, in order to ensure a smooth lateral transition of the water flow, the starting turning point of the wide-tail pier was selected at the point where the width of the original gate wall changed, 18.33m from the end of the gate pier; (2) According to engineering experience, the starting turning point of the wide-tail pier was selected at 8m from the end of the gate pier, with a contraction ratio of 0.5 and a corresponding tail-end turning angle of 20°. The plan layout of the two wide-tail pier body shapes is as follows: Figure 7 As shown.

[0056] The numerical value of each of the structural design parameters can vary uniformly or non-uniformly. For example, the change in the pier top height can be in increments of 0.5m, with the pier top heights of the floodgate being 0.5m, 1m, 1.5m, 2m, and so on. Alternatively, it can vary non-linearly, for example, 1m, 2m, 3m, and 5m.

[0057] The calculation conditions and statistical results are shown in Table 2. Traditional straight-wall wide tail piers are suitable for flood discharge in situations with high tailwater depth and large unit width. However, when the tailwater depth is small or the discharge flow is low, water flow concentration is likely to occur, which will cause a sharp increase in the impact pressure of the downstream floodplain. To increase the applicability of the wide tail pier structure to the discharge flow, an X-type wide tail pier structure was also studied.

[0058] Table 2 Calculation conditions and statistical results for the wide-tail pier scheme

[0059]

[0060] S3: The optimal design scheme of the wide tail pier is determined by using the impact hinge risk value k as the judgment condition. k = f(position of the water jump, water depth of the jump, maximum bottom velocity of the gate chamber, discharge flow rate, water surface line of the gate chamber), where f is a function.

[0061] This invention selects the position of the water jump head, the water depth of the jump head, the maximum near-bottom flow velocity of the gate chamber, the discharge flow rate, and the water surface line of the gate chamber as the influencing factors of the impact hinge risk value k. These influencing factors can accurately describe the impact hinge risk value.

[0062] Next, the most important influencing factors are identified in the calculation of impact hinge risk and assigned the largest coefficient. By setting different levels of importance, the risk value k of the impact hinge can be obtained more accurately.

[0063] In S3, the expression for the impact hinge risk value k is as follows:

[0064] k = n1f1 (position of the water jump) + n2f2 (depth of the water jump) + n3f3 (maximum near-bottom velocity of the lock chamber)

[0065] +n4f4 (discharge flow) +n5f5 (water level in the gate chamber);

[0066] In the formula, f1, f2, f3, f4, and f5 are functions, and n1, n2, n3, n4, and n5 are coefficients, with n1 + n2 + n3 + n4 + n5 = 1. n1, n2, n3, n4, and n5 represent the importance of different influencing factors. The values ​​of n1, n2, n3, n4, and n5 can be different, with larger values ​​indicating greater importance.

[0067] Furthermore, n1≥n2>n3≥n4≥n5. That is, the influence and importance of the position and depth of the hydraulic jump head are generally greater than the influence and importance of the maximum bottom velocity, discharge capacity, and water surface line of the lock chamber.

[0068] The longitudinal flow field results under various schemes are as follows Figure 8 As shown, the water surface line along the path is as follows Figure 9 As shown. According to the settlement results, the addition of the wide tail pier structure has virtually no impact on the flow rate. The optimal design scheme for the wide tail pier is determined using the impact hinge risk value k as the criterion. The recommended layouts for the three structural types are as follows: Figure 10 As shown.

[0069] This invention provides a design method for a wide tail pier of a flood discharge gate. By establishing a mathematical model of a single opening of the flood discharge gate, the law of hydraulic jump can be studied, and the calculation results of various design schemes can be obtained quickly. Through further evaluation of the calculation results, the optimal design scheme of the wide tail pier is determined by using the impact hinge risk value k as a judgment condition. The optimal structural form of the wide tail pier can be determined quickly and accurately.

[0070] Example 2

[0071] A floodgate is designed using the wide tail pier design method of a floodgate as described in Example 1.

[0072] The floodgate described in this invention is designed using the design method described in Example 1. The optimized design of the floodgate's wide tail pier can effectively reduce the risk of water jets impacting the gate hinges and ensure the safe operation of the floodgate.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for a wide tail pier of a flood discharge gate, characterized in that, Includes the following steps: S1: Establish a mathematical model of a single outlet of the floodgate; determine the structural design parameters of the wide tail pier, including the tail pier type, the width of the outlet before contraction, the tail pier angle, the contraction ratio, the outlet width, the length of the contraction section, and the top elevation of the pier; S2: Combine the structural design parameters to form multiple wide tail pier design schemes, and input each design scheme into the mathematical model for calculation to obtain the calculation results; S3: Impact hinge risk value k The impact hinge risk value is used as a criterion to determine the optimal design scheme for the wide-tail pier. k The expression is as follows: k = n 1 f 1 (Water Jump Head Position) + n 2 f 2 (leaping head water depth) + n 3 f 3 (Maximum flow velocity at the bottom of the gate chamber) + n 4 f 4 (outflow) + n 5 f 5 (Water level in the lock chamber); In the formula, f 1. f 2. f 3. f 4. f 5 are functions, n 1. n 2. n 3. n 4. n 5 represents the coefficients. n 1+ n 2+ n 3+ n 4+ n 5 = 1.

2. The design method for a wide tail pier of a flood discharge gate according to claim 1, characterized in that, In S3, n 1≥ n 2> n 3≥ n 4≥ n 5.

3. The design method for a wide tail pier of a flood discharge gate according to claim 1, characterized in that, In S1, the model scope for establishing the mathematical model of a single-hole floodgate is the area above the dam. l 1m to the bottom of the dam l 2m, l 2> l 1.

4. The design method for a wide tail pier of a flood discharge gate according to claim 1, characterized in that, In S1, when establishing the mathematical model of a single outlet of the flood discharge gate, the upstream boundary and the downstream boundary are both water level boundaries.

5. The design method for a wide tail pier of a flood discharge gate according to claim 1, characterized in that, In S1, the tail pier type includes rectangular, Y-shaped and X-shaped.

6. The design method for a wide tail pier of a flood discharge gate according to claim 1, characterized in that, In S1, the structural design parameters also include whether the bottom is open and the bottom open height.

7. A design method for a wide tail pier of a flood discharge gate according to any one of claims 1-6, characterized in that, The numerical value of each of the structural design parameters is initially determined based on theoretical calculations.

8. The design method for a wide tail pier of a flood discharge gate according to claim 7, characterized in that, The values ​​of each of the structural design parameters vary uniformly.

9. A floodgate, characterized in that, The design was obtained using the design method for a wide tail pier of a floodgate as described in any one of claims 1-8.

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