Method for determining crest elevation of rolling type earth and rockfill dam in water conservancy and hydropower engineering

Abstract

The invention discloses a method for determining the crest elevation of a rolling type earth and rockfill dam in water conservancy and hydropower engineering. Comprising the following steps: collecting meteorological data, determining a calculated wind speed, determining a water area plane, determining an equivalent wind area length, determining a water area average depth, determining an average wave height and an average wave period, determining an average wavelength, determining a designed wave climb height, determining a wind congestion water surface height, determining a safe height, determining a dam body total superelevation, and determining a wave wall height. And determining the dam crest elevation. The method is suitable for earth and rockfill dams such as clay core-wall rockfill dams, asphalt concrete core-wall rockfill dams, asphalt concrete face rockfill dams, concrete face rockfill dams and homogeneous dams. The method not only has scientificity, accuracy, comprehensiveness, systematicness, safety and economical efficiency, but also is easy to popularize and apply, and has important significance for improving the accuracy and safety of dam design.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower engineering technology, specifically to a method for determining the crest elevation of a roller-compacted earth-rock dam in water conservancy and hydropower engineering. Background Technology

[0002] In water conservancy and hydropower projects, the determination of the dam crest elevation is directly related to the safety and stability of the dam body. While traditional methods for determining dam crest elevation consider various factors, they often have shortcomings in calculating wave run-up, wind damming, and safety margins, leading to designed dam crest elevations that may not meet actual safety requirements. Therefore, a more scientific, accurate, and comprehensive method for determining dam crest elevation is needed. Summary of the Invention

[0003] The present invention aims to provide a method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project. This method comprehensively considers various factors such as meteorological data, water characteristics, wave characteristics, wind-induced water level rise, safety height increase, and dam settlement to ensure that the designed dam crest elevation meets actual safety requirements.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project includes the following steps: Collect meteorological data: Collect data from the meteorological bureau in the area where the dam site is located to determine the multi-year average maximum wind speed and prevailing wind direction; Determine the calculation wind speed: Based on the dam level, the calculation wind speed is determined by using 1.5 to 2.0 times the multi-year average annual maximum wind speed (for Class I and II dams) or 1.5 times (for Class III, IV, and V dams). Determine the water area level: Determine a water area level based on the characteristic water level elevation initially determined by the hydrological plan; Determine the equivalent wind zone length: The equivalent wind zone length is obtained by drawing the principal ray and rotating it for calculation, according to the formula. Determine the average depth of the water body: Draw a topographic profile along the wind direction and calculate the ratio of the water area to the width of the water surface to obtain the average depth of the water body; Determine wave characteristics: including mean wave height, mean wave period, and mean wavelength, which are calculated using formulas; Determine the design wave run-up: Calculate the average wave run-up using the formula based on parameters such as wave characteristics, face type, and slope coefficient. Determine the height of the wind-induced water level obstruction: Based on parameters such as the length of the wind zone, the comprehensive friction coefficient, the angle between the calculated wind direction and the normal to the dam axis, and the average water depth, the height of the wind-induced water level obstruction is calculated using the formula. Determine the safety height increase: Based on the different levels of the dam and the operating conditions, the safety height increase value is obtained by referring to the table; Determine the total freeboard of the dam: The total freeboard of the dam is calculated using a formula based on parameters such as maximum wave run-up, wind damming height, and safety margin. Determine the height of the breakwater: According to relevant regulations, the design height of the breakwater is generally 1.0 to 1.2 meters to ensure that it does not obstruct people's view and does not affect pedestrian safety; Determine the dam crest elevation: Based on parameters such as (normal water level, design flood level, check flood level), plus the total freeboard of the dam body, calculated settlement height, and wave wall height, take the maximum value to determine the dam crest elevation.

[0005] In another aspect, the present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0006] In another aspect, the present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described above.

[0007] As can be seen from the above technical solution, the method for determining the crest elevation of a roller-compacted earth-rock dam in water conservancy and hydropower engineering of the present invention has the following specific beneficial effects: (1) Scientificity and accuracy: This invention takes into account a variety of factors and ensures the scientificity and accuracy of the determination of the dam crest elevation through precise calculation formulas and steps.

[0008] (2) Comprehensiveness and systematicness: The method of the present invention covers the entire process from meteorological data collection to dam crest elevation determination, and is comprehensive and systematic.

[0009] (3) Safety and economy: By accurately calculating the dam crest elevation, the safety and stability of the dam body are ensured, while also taking into account the economy.

[0010] (4) Easy to promote and apply: The method of the present invention is easy to understand and operate, applicable to various types of earth-rock dams, and has broad promotion and application value.

[0011] (5) The calculation system is complete and highly accurate: The system integrates 12 key parameters such as wind speed, wind zone, water depth, wave run-up, wind jam height, and safety height, and provides graded formulas and interpolation rules (such as the piecewise formula for the slope coefficient m), which avoids the errors caused by parameter simplification in traditional methods and significantly improves the scientific nature of dam crest elevation design.

[0012] (6) Advanced method for determining wind zone length: The innovative method of "rotating the main ray ±7.5° 12 times" is adopted. Through multi-angle ray weighted calculation, the wind field effect under complex terrain is more realistic. It is especially suitable for canyon-type reservoirs and is more consistent with the actual wind energy distribution than the traditional single main wind direction method.

[0013] (7) Strong versatility for multiple dam types: It is clearly applicable to all types of roller-compacted earth-rock dams, such as clay core wall, asphalt concrete core wall / panel, concrete panel, and homogeneous dam. There is no need to adjust the calculation logic for different dam types, which greatly reduces the learning and implementation costs for design units.

[0014] (8) Dual optimization of safety and economy: By combining the graded wind speed values ​​(1.5 to 2.0 times for dams of level 1 to 2 and 1.5 times for dams of level 3 to 5) with the standard safety height increase table, the dam body can be increased excessively while ensuring flood control safety, which can reduce the amount of earthwork by 10% to 15%.

[0015] (9) Convenient digital implementation: The computer program storage medium is equipped to modularize the 12-step calculation process, which can be directly embedded into the CAD / BIM design platform to realize the automation from meteorological data input to dam crest elevation output. The efficiency is improved by more than 80% compared with traditional manual calculation, and it is especially suitable for multi-scheme comparison in the feasibility study stage. Attached Figure Description

[0016] Figure 1 This is a flowchart of the present invention; Figure 2 This is an example of calculating the average water depth according to the present invention; Figure 3 This is a schematic diagram illustrating the calculation of the equivalent wind zone length according to the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0018] like Figure 1 As shown in this embodiment, the method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project includes the following steps: (1) Collect data from the meteorological bureau in the area where the dam site is located to determine the multi-year average maximum wind speed and prevailing wind direction; (2) According to the specifications, when the dam is a Class 1 or Class 2 dam, the annual maximum wind speed is 1.5 to 2.0 times the multi-year average, and when the dam is a Class 3, Class 4 or Class 5 dam, the annual maximum wind speed is 1.5 times the multi-year average. The calculated wind speed W is determined accordingly. (3) Determine a water area level based on the characteristic water level elevation initially determined by the hydrological plan; (4) Determine the equivalent wind zone length D based on the water surface; 1) Based on the determined dam axis and prevailing wind direction, draw the main ray that intersects the dam axis; 2) Based on the fact that the main ray rotates clockwise by 7.5° each time, for a total of 6 times, we can obtain... and Then, rotate counterclockwise by 7.5° each time, for a total of 6 times, to obtain... and ; 3) Finally, the equivalent wind zone length D is obtained using the following formula. Figure 3 This is a schematic diagram illustrating the calculation of the equivalent wind zone length according to the present invention;

[0019] In the formula: D—Equivalent wind zone length; D—The distance from the calculation point to the boundary of the water area, taken as ±1, ±2, ±3, ±4, ±5, ±6; —The angle between the i-th ray and the principal ray is equal to i × 7.5°; (5) Determine the average depth H of the water area m H can be obtained by drawing a topographic profile along the wind direction. m The calculated water level should be consistent with the static water level under the corresponding design conditions.

[0020] H m =Water area / Water surface width (6) Determine the mean wave height h m (m) and mean wave period T m (s); Calculated according to the following formula:

[0021]

[0022] In the formula: h m —Mean wave height, m; T m —Mean wave period, seconds; W—Calculated wind speed, m / s; D—Length of the wind zone, in meters; H m —Average water depth, in meters; an example of calculating average water depth is shown below. Figure 2 As shown; g—acceleration due to gravity, taken as 9.81 m / s²; (7) Determine the average wavelength Lm (m), calculated using the following formula, yields:

[0023] (8) Determine the design wave run-up height R.

[0024] 1) When m = 1.5~5.0, the average wave run-up is calculated using the following formula:

[0025] In the formula: R m = Average wave rise, m; m—slope coefficient of a single slope, m=2.5; K △ —The roughness and permeability coefficient of the slope, if the angle of failure is That is, equal to cot ; K w —The empirical coefficients can be found in the table below.

[0026] Roughness permeability coefficient K △

[0027] Empirical coefficient K w

[0028] 2) When m ≤ 1.25, the average wave run-up is calculated using the following formula:

[0029] In the formula: R0—mean wave height h under calm conditions m =1m, smooth and impermeable facing (K) △ The elevation value for (=1) can be found in the table below.

[0030] R0 value

[0031] 3) When 1.25 < m < 1.5, the value can be determined by interpolation from the calculated values ​​of m = 1.25 and m = 1.5.

[0032] (9) Determine the height e of the wind-blown water surface 1) The height of the water surface obstructed by wind is calculated using the following formula:

[0033] In the formula: e—Height of wind-induced water level obstruction at the calculation point, in meters; D—Length of the wind zone (m); K f —Comprehensive friction coefficient, taken as 3.6×10 -6 ; β—Calculate the angle between the wind direction and the normal to the dam axis, (°); H m —Average water depth (m) within the wind zone; W — Calculated wind speed (m / s).

[0034] (10) Determine the safety height increase A The safety enhancement value A is obtained from the table below, depending on the dam's different levels, normal operating conditions, and emergency operating conditions.

[0035] Safety increases A value

[0036] (11) Determine the total superelevation of the dam body The freeboard of the dam crest above the reservoir's still water level is calculated using the following formula:

[0037] In the formula: y—Dam crest superelevation, in meters; R—maximum wave rise on the dam slope, in meters; e—Maximum wind resistance height above water surface, in meters; A—Safety height increased, m.

[0038] (12) Determine the height of the wave wall To prevent waves from overturning the dam crest and ensure the safety of the dam structure, the height of the wave wall must be designed to not obstruct people's view or affect pedestrian safety. According to relevant regulations, the height of the wave wall is generally 1.0 to 1.2 meters.

[0039] When a wave wall is installed on the upstream side of the dam crest, the dam crest freeboard can be changed to the requirement for the top of the wave wall. However, under normal operating conditions, the dam crest should be 0.5m above the still water level; under emergency operating conditions, the dam crest should not be lower than the still water level.

[0040] (13) Determine the dam crest elevation Therefore, the dam crest elevation is determined based on the maximum value of the normal water level, design flood level, check flood level + total dam height + calculated settlement height - wave wall height.

[0041] Specifically, Safety enhancement in earthquake zones should include increasing earthquake subsidence and seismic surge height.

[0042] The design dam crest elevation is equal to the sum of the reservoir static water level and the dam crest freeboard. It should be calculated according to the following operating conditions, and the maximum value should be taken: (1) Normal water level plus dam crest freeboard under normal operating conditions; (2) Design flood level plus dam crest freeboard under normal operating conditions; (3) Check flood level plus dam crest freeboard under extraordinary operating conditions; (4) Normal water level plus dam crest freeboard under extraordinary operating conditions, plus earthquake safety height.

[0043] Under normal operating conditions, the dam crest should be 0.5m above the still water level; under emergency operating conditions, the dam crest should not be lower than the still water level.

[0044] The superelevation for settlement after completion should be reserved on the dam crest, generally not exceeding 1% of the dam height.

[0045] The average depth H of the water area m To calculate the area S (m²) of the topographic profile along the wind direction. 2 ) / water surface width L (m).

[0046] The characteristic water levels are the normal storage water level, the design flood level, and the check flood level.

[0047] The average wavelength L m It needs to be obtained through trial and error.

[0048] Specifically, the beneficial effects of the embodiments of the present invention are as follows: (1) Verification of the accuracy of the calculation of the equivalent wind zone length D Traditional method: Only the straight-line distance in the prevailing wind direction is taken, resulting in D = 2.8 km. The method of this invention: using the algorithm of "major ray ± 7.5° rotation 12 times", the weighted calculation yields D = 3.45km. Effect: The wind zone length is increased by 23%, which more accurately reflects the wind field of the canyon reservoir and avoids underestimating the effect of waves.

[0049] (2) Comparison of wave rise R calculation Parameters: Wind speed W = 25 m / s (Class 1 dam, take 1.8 times), dam slope m = 2.5, facing is asphalt concrete (KΔ = 1.0) Traditional empirical formula: Without considering slope segments, R = 1.8m The method of this invention: R = 2.34m is calculated according to the formula m = 2.5 (considering Kw = 1.16). Effect: The climb rate is increased by 30%, directly reducing the design error of the dam crest superelevation.

[0050] (3) Comparison of calculations for wind-induced water surface height e Parameters: β=30°, Hm=35m, D=3.45km Traditional simplified formula: e = 0.12m (ignoring the correction for the included angle β) The method of this invention: Calculation yields e = 0.21m (including β correction) Effect: Increases height by 75%, avoiding the risk of overtopping below the check flood level.

[0051] (4) Enhanced security A-level optimization verification Dam Classification: Class 1 dam, under normal operating conditions Traditional one-size-fits-all value: A=1.2m (without class distinction) The method of this invention: By referring to the table, A = 1.5m (normal conditions for a Class 1 dam). Effect: Although the height is increased by 0.3m, it meets the requirements of the classification standards and avoids over-design.

[0052] In summary, the embodiments of the present invention improve the design accuracy of dam crest elevation by more than 20% without significantly increasing costs through refined wind zone calculation, segmented wave run-up formula, and graded safety heightening. It is particularly suitable for complex conditions such as high dams and canyon reservoirs, and verifies the unity of scientific validity, safety, and economy.

[0053] In another aspect, the present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0054] In another aspect, the present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described above.

[0055] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the methods for determining the crest elevation of a roller-compacted earth-rock dam in the above embodiments.

[0056] It is understood that the systems, devices, and storage media provided in the embodiments of the present invention correspond to the methods provided in the embodiments of the present invention, and the explanations, examples, and beneficial effects of the relevant content can be referred to the corresponding parts of the above methods.

[0057] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0059] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project, characterized in that, Includes the following steps, S1. Collect data from the meteorological bureau in the area where the dam site is located to determine the multi-year average maximum wind speed and prevailing wind direction; S2. According to the specifications, when the dam is of level 1 or 2, the wind speed is 1.5 to 2.0 times the annual average maximum wind speed. When the dam is of level 3, 4 or 5, the wind speed is 1.5 times the annual average maximum wind speed. The wind speed W is then used to determine the calculation wind speed. S3. Determine a water area level based on the characteristic water level elevation initially determined by the hydrological plan; S4. By drawing the main ray and rotating it, the equivalent wind zone length D is obtained according to the formula. S5. Determine the average depth H of the water area. m H can be obtained by constructing a topographic profile along the wind direction. m The average depth of the water body is obtained by calculating the ratio of the water area to the width of the water surface. S6. Determine wave characteristics: including average wave height, average wave period, and average wavelength, which are calculated using formulas; S7. Determine the design wave run-up: Calculate the average wave run-up using the formula based on parameters such as wave characteristics, face type, and slope coefficient. S8. Determine the height of the wind-induced water level obstruction: Based on parameters such as the length of the wind zone, the comprehensive friction coefficient, the angle between the calculated wind direction and the normal to the dam axis, and the average water depth, the height of the wind-induced water level obstruction is calculated using the formula. S9. Determine the safety height increase: Based on the different levels of the dam and the operating conditions, refer to the table to obtain the safety height increase value; S10. Determine the total freeboard of the dam: The total freeboard of the dam is calculated using the formula based on parameters such as maximum wave run-up, wind damming height, and safety margin. S11. Determine the height of the breakwater: Design the height of the breakwater according to relevant regulations to ensure that it does not obstruct people's view and does not affect pedestrian safety; S12. Based on parameters such as normal water level, design flood level, check flood level, total dam height, calculated settlement height, and wave wall height, the maximum value is taken to determine the dam crest elevation.

2. The method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project according to claim 1, characterized in that: Step S4 specifically includes, S41. Based on the determined dam axis and prevailing wind direction, draw the main ray and make it intersect the dam axis; S42. Based on the fact that the main ray rotates clockwise by 7.5° each time, for a total of 6 times, we obtain... and ; Then rotate counterclockwise by 7.5° each time, for a total of 6 times, to obtain... and ; S43. Finally, the equivalent wind zone length D is obtained according to the following formula; In the formula: D—Equivalent wind zone length; D—The distance from the calculation point to the boundary of the water area, taken as ±1, ±2, ±3, ±4, ±5, ±6; —The angle between the i-th ray and the principal ray is equal to i × 7.5°.

3. The method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project according to claim 1, characterized in that: The average depth H of the water area in step S5 m The calculation formula is as follows: Hm = Area of ​​water body / Width of water surface.

4. The method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project according to claim 1, characterized in that: The calculation formula for step S6 is as follows: In the formula: h m —Mean wave height, m; T m —Mean wave period, seconds; W—Calculated wind speed, m / s; D—Length of the wind zone, in meters; H m —Average water depth, in meters; g—gravitational acceleration, taken as 9.81 m / s².

5. The method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project according to claim 4, characterized in that: The calculation formula for step S7 is as follows: 。 6. The method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project according to claim 5, characterized in that: Step S7 specifically includes, 1) When m = 1.5~5.0, the average wave run-up is calculated using the following formula: In the formula: R m It is the average wave rise, in meters (m). M is the slope coefficient of a single slope, m=2.5; K △ It is the roughness and permeability coefficient of the slope. If the angle of failure is... That is, equal to cot ; K w It is an empirical coefficient; 2) When m ≤ 1.25, the average wave run-up is calculated using the following formula: In the formula: R0 is the mean wave height h under calm conditions. m When the surface is 1m, the smooth, impermeable surface is K. △ =1 climb value; 3) When 1.25 < m < 1.5, the value can be determined by interpolation from the calculated values ​​of m = 1.25 and m = 1.

5.

7. The method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project according to claim 6, characterized in that: Step S8 specifically includes, The height of the water surface obstructed by wind is calculated using the following formula: In the formula: E is the wind-induced water level rise at the calculation point, in meters (m). D is the length of the wind zone, in meters; K f This is the overall friction coefficient, taken as 3.6 × 10⁻⁶. -6 ; β is the angle between the wind direction and the normal to the dam axis, in degrees. H m It is the average water depth within the wind zone, in meters (m). W represents the calculated wind speed, measured in m / s.

8. The method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project according to claim 7, characterized in that: Step S10 specifically includes, The freeboard of the dam crest above the reservoir's still water level is calculated using the following formula: In the formula: Y represents the superelevation of the dam crest, in meters (m). R is the maximum wave run-up height on the dam slope, in meters; E is the maximum wind resistance height above the water surface, in meters (m). A represents the safety height, measured in meters (m).

9. The method for determining the crest elevation of a roller-compacted earth-rock dam in a water conservancy and hydropower project according to claim 8, characterized in that: Step S12 specifically includes, The design dam crest elevation is equal to the sum of the reservoir's static water level and the dam crest freeboard, calculated according to the following operating conditions, and the maximum value is taken: ( 1) The superelevation of the dam crest under normal storage conditions plus normal operating conditions; (2) The superelevation of the dam crest under normal operating conditions plus design flood level; (3) The superelevation of the dam crest under extraordinary operating conditions plus check flood level; (4) The superelevation of the dam crest under extraordinary operating conditions plus earthquake safety level.

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