Method for calculating breach of barrier dam
By dividing the landslide dam breach process into broad-crested weir and open channel modes, and using a two-dimensional hydrodynamic model and a hyperbolic law model to calculate the breach characteristics, the problem that traditional models cannot describe the three-dimensional characteristics of landslide dam breaches is solved, and a more accurate simulation of the breach process is achieved.
Patent Information
- Application Number
- CN202511463001.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-14
- Publication Date
- 2026-01-13
AI Technical Summary
Existing technologies struggle to accurately simulate the three-dimensional features and complex physical processes during the breach of a landslide dam, especially the breach path. Traditional one-dimensional and two-dimensional models cannot fully describe the spatial scale effects and dynamic coupling processes of landslide dams.
The breaching process of the landslide dam is divided into two modes: broad-crested weir and open channel. The breach width and flow rate of each calculation section are calculated using a two-dimensional hydrodynamic model. The breach erosion rate is calculated using a hyperbolic law model. Combined with the shear stress of the water flow and the erosion function, a three-dimensional description of the characteristics is achieved.
It achieves a detailed description of the landslide dam failure process, reduces the complexity of the three-dimensional model, reflects the spatial continuity and variability of the failure process, and the calculation results are more consistent with the actual situation.
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Figure CN121328388A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of water conservancy and disaster simulation, and particularly relates to a method for calculating breach of barrier dam. BACKGROUND
[0002] In recent years, landslides and debris flow frequently occur in high mountain and canyon areas, forming super-long distance barrier dams. The main mode of these dams is overtopping breach. After the overflow of the barrier lake, the dam top section is essentially converted into a flow passage, leading to the evolution of breach development from local point erosion to longitudinal strip erosion. Traditional methods are difficult to accurately capture the spatial scale effect and dynamic coupling process.
[0003] Accurate simulation of the breach process of barrier dam is of great significance for predicting flood evolution and assessing disaster risk. Current barrier dam breach calculation models are mainly one-dimensional and two-dimensional. Although these models can reflect some information in the breach process to some extent, they cannot comprehensively and accurately describe the three-dimensional characteristics and complex physical processes of barrier dam breach, especially the breach path, because they ignore the influence of the length direction and spatial variation along the river. Therefore, a method for calculating the breach of barrier dam is needed to describe the breach process of barrier dam. SUMMARY
[0004] The purpose of the present application is to provide a method for calculating the breach of barrier dam, which accurately describes the three-dimensional characteristics of each calculation section in the breach process of barrier dam.
[0005] To solve the above problems, the present application provides a method for calculating the breach of barrier dam, comprising:
[0006] S100: obtaining the upper water head under the initial state of the barrier dam , the initial velocity of water flow , the initial reservoir water level , and the initial breach width ; S200: selecting a first subsection node of the barrier dam according to the upper water head , and selecting a second subsection node according to the dam shape ; S300: marking the river section upstream of the first subsection node and the river section downstream of the second subsection node as wide-top weir river section, and marking the river section between the first subsection node and the second subsection node as open channel river section; S400: dividing the barrier dam along the potential breach path into a plurality of continuous calculation sections, and sequentially judging whether each calculation section belongs to the wide-top weir river section or the open channel river section; S500: Based on whether the calculated cross section belongs to the broad-crested weir section or the open channel section, the breach width and breach flow of each calculated cross section are calculated sequentially using a two-dimensional hydrodynamic model.
[0007] Furthermore, in the above-mentioned method for calculating the breach of a landslide dam, S500 includes: S501: Given the initial velocity and flow rate increment of the water flow, the average velocity of the water flow at each calculation section is calculated iteratively in sequence. S502: Based on the fact that each of the calculated cross sections belongs to the broad-crested weir section or the open channel section, and the average water level elevation and the average elevation of the breach bottom of each of the calculated cross sections, the breach flow rate and the average water velocity of each calculated cross section are obtained. S503: Calculate a first intermediate quantity based on the average flow velocity and the breach flow rate at each of the calculation sections; S504: Calculate the drop depth of each of the calculated sections based on the water level elevation and the breach bottom elevation of each calculated section; S505: Calculate the flow shear stress of each of the calculated sections based on the drop depth of each section and the average flow velocity; S506: The hyperbolic law model is used as the breach erosion rate model for calculation to obtain the critical shear stress of the water flow, and the erosion function is obtained based on the critical shear stress of the water flow. S507: The relationship between reservoir capacity and water level is obtained based on water balance conditions and on-site measurements; S508: Using the hyperbolic law model as the breach erosion rate model, the unit time required for water flow to pass through each calculated section, as well as the breach undercut height and the breach bottom elevation of each calculated section are calculated based on the erosion function. S509: Calculate the breach width, breach side slope, and breach flow rate for each calculation section based on the initial breach width and the breach bottom elevation of the calculation section.
[0008] Furthermore, in the above-mentioned calculation method for the breach of a landslide dam, section S501... The first formula for calculating the average velocity of the water flow at each of the calculation sections is: (1) in, For the first The average velocity of the water flow at each of the calculated cross sections, For the first The average velocity of the water flow at each of the calculated cross sections, For speed increments, The initial velocity of the water flow is given.
[0009] Furthermore, when the calculation section mentioned in the above-mentioned method for calculating the breach of a landslide dam belongs to the broad-crested weir section, then the first... The breach flow rate at the calculated cross section The formula for calculation is: (2) in, For the first The breach width of the calculated cross section, For the first The water level elevation of the calculated cross section, The initial reservoir water level, For the first The elevation of the bottom of the breach in the calculated cross section. This is the initial bottom elevation of the breach. For the first The average velocity of the water flow at each of the calculated cross sections, For the comprehensive flow coefficient, For inflow traffic, The reservoir water level elevation, The relationship between reservoir capacity and water level; The broad-crested weir section of the river adopts the broad-crested weir breach mode and is affected by the cascade process. The second formula for calculating the average velocity of the water flow at each of the calculation sections is: (3) in, For the first The breach flow rate at the calculated cross section, For the first The water depth at the calculated cross section. For the broad-crested weir coefficient, For the first The average water level elevation of the calculated cross section. For the first The average elevation of the breach bottom at each calculated cross section. For the first The first intermediate quantity of the calculated cross section; When the calculated cross-section belongs to the open channel section, then the first... The breach flow rate at the calculated cross section The formula for calculation is: (4) The open channel section adopts the open channel breach mode, and is not affected by the cascade process. The average velocity of the water flow at each of the calculated cross sections. The second calculation formula is: (5).
[0010] Furthermore, in the above-mentioned method for calculating the breach of a landslide dam, S503, in the case of the broad-crested dam breach mode, by simultaneously solving formulas (1), (2), and (3), the following is obtained: The formula for calculating the first intermediate quantity of the calculated cross section is: (6.1) in, For the first The depth of the erosion at the calculated cross section. For the first The water level drop height of the calculated cross section; In the open channel failure mode, by simultaneously solving formulas (1), (4), and (5), we obtain the first... The formula for calculating the first intermediate quantity of the calculated cross section is: (6.2).
[0011] Furthermore, in the above-mentioned calculation method for the breach of a landslide dam, section S504... When the calculated cross section belongs to the broad-crested weir section, then the first... The depth of the drop at the calculated cross section The formula for calculation is: (7) in, The coefficient for a broad-crested weir; Specifically, when the calculated cross-section belongs to the open channel section, then the first... The depth of the drop at the calculated cross section The formula for calculation is: (8).
[0012] Furthermore, in the above-mentioned calculation method for the breach of a landslide dam, section S505... When the calculated cross section belongs to the broad-crested weir section, then the first... The water flow shear stress at the calculated cross section The calculation formula is: (9) in, The density of water, This is the Manning coefficient; If the first If the calculated cross section belongs to the open channel section, then the first cross section... The water flow shear stress at the calculated cross section The calculation formula is: (10) in, For water density, It is the acceleration due to gravity. For the first The hydraulic radius of the calculated cross section. For the slope.
[0013] Furthermore, the calculation formula for the critical shear stress of water flow described in S506 of the above-mentioned method for calculating the breach of a landslide dam is as follows: (11) in, The critical shear stress of the water flow is... The median particle size of the dam material. For soil density, For water density, It is the internal friction angle; The formula for calculating the erosion function is: (12) in, This represents the actual shear stress of the water flow. The unit transformation factor, and For erosion parameters.
[0014] Furthermore, the formula for calculating the relationship between reservoir capacity and water level in S507 of the above-mentioned landslide dam breach calculation method is as follows: (13) in, The reservoir water level elevation is [missing information]. As the benchmark water level, These are the fitting coefficients for the storage capacity curve; Water flows through S508. The unit time required for each of the aforementioned calculation sections : (14) No. The depth of the erosion at the calculated cross section The formula for calculation is: (15) Among them, the The calculated cross-sections The second intermediate quantity is calculated as follows: (16) Therefore, the first The elevation of the breach bottom of the calculated cross section. The formula for calculation is: (17) No. The water level elevation of the calculated cross section is (18).
[0015] Furthermore, in the above-mentioned calculation method for the breach of a landslide dam, section S509... The breach width of the calculated cross-section is: (19) No. The slope of the breach side bank of the calculated cross section is: (20) in, For the first The slope of the breach side bank of the calculated cross section. For the first The slope of the breach side bank of the calculated cross section. The initial slope of the breach side bank. and These are the coefficients of the hyperbolic ulcer model; No. When the calculated cross section belongs to the broad-crested weir section, then the first... The breach flow rate at each calculated cross section is: (twenty one) No. When the calculated cross-section belongs to the open channel section, then the first cross-section... The breach flow rate at each calculated cross section is: (twenty two).
[0016] The technical solution of this invention has the following beneficial effects: It divides the landslide dam failure mode into broad-crested weirs and open channels, segments them by distance, and calculates the landslide dam failure process at different stages separately. It utilizes existing mature two-dimensional calculation models to calculate the relevant parameters of each cross-section, reducing the complexity of directly constructing a three-dimensional model, while allowing for more detailed consideration of the breach characteristics at different locations. Furthermore, it uses the parameters obtained from the previous calculation cross-section as the starting calculation parameters for the next calculation cross-section, realizing information transfer and continuous calculation between calculation cross-sections. This method can reflect the spatial continuity and variability of the failure process, making the calculation results more consistent with reality. Attached Figure Description
[0017] Figure 1 This is a flowchart of an embodiment of the present invention; Figure 2 This is a schematic diagram of the calculated cross-sectional segmentation of the ulceration in the embodiment of the present invention; Figure 3 This is a schematic diagram of the calculation cross-sectional parameter transfer of the rupture in the embodiment of the present invention; Figure 4 This is a schematic diagram of the longitudinal cross-sectional division of the landslide dam along the direction of water flow in the embodiment of the present invention; Figure 5 This is a side view of the calculated cross section in the embodiment of the present invention; Figure 6 This is a top view of the calculated cross section in the embodiment of the present invention; Figure 7 This is a schematic diagram of the intermediate-breakdown type breakdown path calculation in the embodiment of the present invention; Figure 8 This is a schematic diagram of the breakdown path calculation for the side-breakdown type in the embodiment of the present invention; Figure 9 This is a comparison chart of the flow rate at the breach in the embodiment of the present invention. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.
[0019] The embodiments of the present invention will now be described with reference to the accompanying drawings.
[0020] refer to Figure 1 This invention provides a method for calculating the breach of a landslide dam, which specifically includes the following steps: S100: Obtain the upstream head of the landslide dam in its initial state. Initial velocity of water flow Initial reservoir water level Initial ulcer width ; S200: Select the first segment node of the landslide dam based on the upstream head. At the same time, the second segment node was selected based on the dam body shape. ; Specifically, the distance between the first segment nodes The distance from the upstream vertex of the dam's top surface is: ; S300: The node located at the first segment node The upstream section and the section located at the second segment node The downstream section is marked as the broad-crested weir section, located at the first segment node. and the second segment node The river sections between these points are marked as open channel sections; S400: Divide the landslide dam along the potential breach path into several consecutive calculation sections, and determine in turn whether each calculation section belongs to the broad-crested weir section or the open channel section; S500: Based on whether the calculated cross section belongs to the broad-crested weir section or the open channel section, the breach width and breach flow of each calculated cross section are calculated sequentially using a two-dimensional hydrodynamic model.
[0021] Specifically, the S500 includes: S501: Given the initial velocity and flow rate increment, the average velocity of the water flow at each calculation section is calculated iteratively. The first formula for calculating the average velocity of the water flow at each calculation section is: (1) in, For the first The average velocity of water flow at the calculated cross-section. For the first The average velocity of the water flow at each calculated cross section, For speed increments, The initial velocity of the water flow is given.
[0022] S502: Based on the fact that each calculation section belongs to the broad-crested weir section or the open channel section, and the average water level elevation and the average breach bottom elevation of each calculation section, the breach flow rate and the average flow velocity of each calculation section are obtained. When the calculated cross-section belongs to the aforementioned broad-crested weir section, then the first... The breach flow rate at each calculated cross section The formula for calculation is: (2) in, For the first The width of the breach in each calculated cross-section, For the first The water level elevation of each calculated cross section, The initial reservoir water level, For the first The elevation of the bottom of the breach in each calculated cross section. This is the initial bottom elevation of the breach. For the first The average velocity of water flow at each calculation section For the comprehensive flow coefficient, For inflow traffic, The reservoir water level elevation, The relationship between reservoir capacity and water level; The broad-crested weir section adopts the broad-crested weir breach mode and is affected by the cascading water process. Average velocity of water flow at each calculation section The second calculation formula is: (3) in, For the first The breach flow rate at each calculated cross section, For the first The water depth at each calculated cross section For the broad-crested weir coefficient, For the first The average water level elevation of each calculation section For the first The average elevation of the breach bottom at each calculated cross section. For the first The first intermediate quantity of the calculated cross section; When the calculated cross-section belongs to the aforementioned open channel section, then the first... The breach flow rate at each calculated cross section The formula for calculation is: (4) The open channel section adopts the open channel breach model, which is unaffected by the cascade process. Average velocity of water flow at each calculation section The second calculation formula is: (5).
[0023] S503: In the broad-crested weir failure mode, the first intermediate quantity is calculated based on the average flow velocity and breach flow rate at each calculation section; that is, by combining formulas (1), (2) and (3), the first intermediate quantity is obtained. The formula for calculating the first intermediate quantity of each calculation section is: (6.1) in, For the first The depth of erosion at the calculated cross section. For the first The water level drop height at each calculated cross section; In the open channel breach model, the first intermediate quantity is calculated based on the average flow velocity and breach flow at each calculation section, i.e., by simultaneously solving formulas (1), (4), and (5), the second intermediate quantity is obtained. The formula for calculating the first intermediate quantity of each calculation section is: (6.2).
[0024] S504: Calculate the drop depth of each calculation section based on the water level elevation and the bottom elevation of the breach. Specifically, if the first If the calculated cross section belongs to the broad-crested weir section, then the first cross section... The depth of the drop at each calculated cross section The formula for calculation is: (7) in, The coefficient for a broad-crested weir; Specifically, when the calculated cross-section belongs to the aforementioned open channel section, then the first... The depth of the drop at each calculated cross section The formula for calculation is: (8).
[0025] S505: Calculate the flow shear stress at each calculation section based on the drop depth and average flow velocity at each calculation section; Specifically, the first When the calculated cross section belongs to the broad-crested weir section, then the first cross section... The water flow shear stress at each calculation section The calculation formula is: (9) in, The density of water, This is the Manning coefficient; If the first If the calculated cross-section belongs to the open channel section, then the first cross-section... The water flow shear stress at each calculation section The calculation formula is: (10) in, For water density, It is the acceleration due to gravity. For the first The hydraulic radius of the calculation section, For the slope.
[0026] S506: The hyperbolic law model is used as the breach erosion rate model for calculation to obtain the critical shear stress of the water flow, and the erosion function is obtained based on the critical shear stress of the water flow. The formula for calculating the critical shear stress of water flow is: (11) in, The critical shear stress of the water flow is... The median particle size of the dam material. For soil density, For water density, It is the internal friction angle; The formula for calculating the erosion function is: (12) in, This represents the actual shear stress of the water flow. The unit transformation factor, and For erosion parameters.
[0027] S507: The relationship between reservoir capacity and water level is obtained based on water balance conditions and on-site measurements; the formula for calculating the relationship between reservoir capacity and water level is: (13) in, The reservoir water level elevation, As the benchmark water level, These are the fitting coefficients for the storage capacity curve; S508: Using the hyperbolic law model as the breach erosion rate model, the flow rate through the breach is calculated based on the erosion function. The unit time required for each calculation section : (14) Get the first The calculated depth of the erosion at the breach cross section The formula for calculation is: (15) Among them, the Each calculation section The second intermediate quantity is calculated as follows: (16) Therefore, the first Elevation of the breach bottom of each calculated cross section The formula for calculation is: (17) No. The water level elevation of each calculated section is: (18).
[0028] S509: Based on the initial breach width and the calculated breach bottom elevation of the cross-section. Calculate the breach width, breach bank slope, and breach flow rate for each cross-section. No. The breach width of each calculated section is: (19) No. The slope of the breach side bank at each calculated cross section is: (20) in, For the first The slope of the breach side bank at each calculation section. For the first The slope of the breach side bank at each calculation section. The initial slope of the breach side bank. and These are the coefficients of the hyperbolic ulcer model; No. When the calculated cross section belongs to the broad-crested weir section, then the first cross section... The breach flow rate at each calculated cross section is: (twenty one) No. When the calculated cross-section belongs to the open channel section, then the first cross-section... The breach flow rate at each calculated cross section is: (twenty two) S600: Based on the structural characteristics and failure mechanism of the landslide dam, the failure mode is determined to be either a central failure or a lateral failure, and the failure route is determined based on the central axis of the river channel.
[0029] The S600 specifically includes: S601: Establish a planar coordinate system from the top-down view of the breach to simplify the shape of the river channel; S602: Draw the breach route according to the breach pattern. If it is a central breach, draw the central axis along the river centerline. If it is a lateral breach, draw the central axis along the side bank of the river. S603: Take the horizontal coordinates at equal intervals and extract the points that intersect with the central axis as control points for the breach route; S604: Calculate the x-coordinate of each cross section. The calculation formula is: (twenty three) in, For the first The average velocity of water flow at each cross section.
[0030] S605: Determine the x-coordinate of each calculated section. Does it meet the following requirements: If the conditions are met, the corresponding ordinate is calculated using interpolation. for: (twenty four) S606: Obtain the breakdown path by fitting the coordinates of each calculated section.
[0031] The following is a specific example to illustrate this embodiment. The landslide dam is divided into several continuous calculation sections along the potential breach path, such as... Figure 2 and Figure 3 As shown. Next, it is determined whether each calculated cross-section belongs to a broad-crested weir section or an open channel section, such as... Figure 4 As shown. First, calculate the relevant data for the first calculation section, which belongs to the broad-crested weir section. The initial velocity of the water flow is then used. Calculate the average velocity of the water flow at the first calculation section. :
[0032] Since the first calculation section belongs to the broad-crested weir section, the breach discharge... The formula for calculation is:
[0033] Average velocity of water flow Another calculation formula is:
[0034] Therefore, the first intermediate quantity is:
[0035] The current water depth is:
[0036] Next, the shear stress of the water flow is calculated. for:
[0037] The critical shear stress of water flow is:
[0038] The erosion function is:
[0039] Based on the water balance conditions and on-site measurements, the relationship between reservoir capacity and water level is as follows:
[0040] Cavity erosion height for:
[0041] Then the water level elevation was calculated sequentially. for:
[0042] Breach bottom elevation for:
[0043] The unit time required for water to flow from its initial position through the first calculated cross section for:
[0044] Therefore, the width of the ulcer for:
[0045] slope of the breach side bank for:
[0046] rupture flow for:
[0047] Therefore, the calculation of the first calculation section is completed, and the parameters of the second calculation section are calculated using the parameters of the first section.
[0048] The average velocity of water flow at the second calculation section :
[0049] The second calculation section belongs to the open channel section, therefore the breach discharge... The formula for calculation is:
[0050] Average velocity of water flow Another calculation formula is:
[0051] Therefore, the first intermediate quantity for:
[0052] Since there is no drop in the open channel failure mode, the shear stress of the water flow is... for:
[0053] The erosion function is:
[0054] Based on the water balance conditions and on-site measurements, the relationship between reservoir capacity and water level is as follows:
[0055] Cavity erosion height for:
[0056] Then the water level elevation was calculated sequentially. for:
[0057] Breach bottom elevation for:
[0058] The unit time required for water to flow from its initial position through the first calculated cross section for:
[0059] Therefore, the width of the ulcer for:
[0060] slope of the breach side bank for:
[0061] The rupture flow rate is :
[0062] Therefore, the calculation for the second calculation section is completed, and the parameters for the third section are calculated using the parameters from the second section, and so on, until the loop is complete. After completing the calculation for all calculation sections, a 3D model can be generated based on the physical properties of each calculation section, where the side view and top view are as follows: Figure 5 and Figure 6 As shown.
[0063] The next step is to determine the breach route. First, a planar coordinate system is established from a top-down view of the breach to simplify the river channel shape and determine the breach pattern, such as... Figure 7 and Figure 8 As shown, the central axis is drawn according to the middle collapse type or the side collapse type. Then, the horizontal coordinates are taken at equal intervals, and the intersection points with the central axis are extracted as control points of the collapse route. The horizontal coordinates of each calculation section are calculated, and the corresponding vertical coordinates are calculated using the interpolation method. Finally, the collapse path is obtained by fitting.
[0064] The final calculated breach flow rate curve shows a maximum measured flow rate of 31,000 m³ / s. 3 / s, the inversion result of this program is 31039.4m. 3 / s, the inversion result is quite close to the measured result, differing by only 0.13%; secondly, the calculated breach flow curve is closer to the measured curve, such as Figure 9 As shown.
[0065] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.
Claims
1. A method for calculating the breach of a landslide dam, characterized in that, include: S100: Obtain the upstream head of the landslide dam in its initial state. Initial velocity of water flow Initial reservoir water level Initial ulcer width ; S200: Select the first segment node of the landslide dam based on the upstream head. At the same time, the second segment node was selected based on the dam body shape. ; S300: The node located at the first segment node The upstream section and the section located at the second segment node The downstream section is marked as the broad-crested weir section, located at the first segment node. and the second segment node The river sections between these points are marked as open channel sections; S400: Divide the landslide dam along the potential breach path into several consecutive calculation sections, and determine in turn whether each calculation section belongs to the broad-crested weir section or the open channel section; S500: Based on whether the calculated cross section belongs to the broad-crested weir section or the open channel section, the breach width and breach flow of each calculated cross section are calculated sequentially using a two-dimensional hydrodynamic model.
2. The method for calculating the breach of a landslide dam according to claim 1, characterized in that: The S500 includes: S501: Given the initial velocity and flow rate increment of the water flow, the average velocity of the water flow at each calculation section is calculated iteratively in sequence. S502: Based on the fact that each of the calculated cross sections belongs to the broad-crested weir section or the open channel section, and the average water level elevation and the average elevation of the breach bottom of each of the calculated cross sections, the breach flow rate and the average water velocity of each calculated cross section are obtained. S503: Calculate a first intermediate quantity based on the average flow velocity and the breach flow rate at each of the calculation sections; S504: Calculate the drop depth of each of the calculated sections based on the water level elevation and the breach bottom elevation of each calculated section; S505: Calculate the flow shear stress of each of the calculated sections based on the drop depth of each section and the average flow velocity; S506: The hyperbolic law model is used as the breach erosion rate model for calculation to obtain the critical shear stress of the water flow, and the erosion function is obtained based on the critical shear stress of the water flow. S507: The relationship between reservoir capacity and water level is obtained based on water balance conditions and on-site measurements; S508: Using the hyperbolic law model as the breach erosion rate model, the unit time required for water flow to pass through each calculated section, as well as the breach undercut height and the breach bottom elevation of each calculated section are calculated based on the erosion function. S509: Calculate the breach width, breach side slope, and breach flow rate for each calculation section based on the initial breach width and the breach bottom elevation of the calculation section.
3. The method for calculating the breach of a landslide dam according to claim 2, characterized in that: In S501, the first The first formula for calculating the average velocity of the water flow at each of the calculation sections is: （1） in, For the first The average velocity of the water flow at each of the calculated cross sections, For the first The average velocity of the water flow at each of the calculated cross sections, For speed increments, The initial velocity of the water flow is given.
4. The method for calculating the breach of a landslide dam according to claim 3, characterized in that: When the calculated cross section belongs to the broad-crested weir section, then the first... The breach flow rate at the calculated cross section The formula for calculation is: （2） in, For the first The breach width of the calculated cross section, For the first The water level elevation of the calculated cross section, The initial reservoir water level, For the first The elevation of the bottom of the breach in the calculated cross section. This is the initial bottom elevation of the breach. For the first The average velocity of the water flow at each of the calculated cross sections, For the comprehensive flow coefficient, For inflow traffic, The reservoir water level elevation, The relationship between reservoir capacity and water level; The broad-crested weir section of the river adopts the broad-crested weir breach mode and is affected by the cascade process. The second formula for calculating the average velocity of the water flow at each of the calculation sections is: （3） in, For the first The breach flow rate at the calculated cross section, For the first The water depth at the calculated cross section. For the broad-crested weir coefficient, For the first The average water level elevation of the calculated cross section. For the first The average elevation of the breach bottom at each calculated cross section. For the first The first intermediate quantity of the calculated cross section; When the calculated cross-section belongs to the open channel section, then the first... The breach flow rate at the calculated cross section The formula for calculation is: （4） The open channel section adopts the open channel breach mode, and is not affected by the cascade process. The average velocity of the water flow at each of the calculated cross sections. The second calculation formula is: （5）。 5. The method for calculating the breach of a landslide dam according to claim 4, characterized in that: In S503, during the broad-crested dam failure mode, by simultaneously applying formulas (1), (2), and (3), the following equation is obtained: The formula for calculating the first intermediate quantity of the calculated cross section is: （6.1） in, For the first The depth of the erosion at the calculated cross section. For the first The water level drop height of the calculated cross section; In the open channel failure mode, by simultaneously solving formulas (1), (4), and (5), we obtain the first... The formula for calculating the first intermediate quantity of the calculated cross section is: （6.2）。 6. The method for calculating the breach of a landslide dam according to claim 5, characterized in that: In S504, the first When the calculated cross section belongs to the broad-crested weir section, then the first... The depth of the drop at the calculated cross section The formula for calculation is: （7） in, The coefficient for a broad-crested weir; Specifically, when the calculated cross-section belongs to the open channel section, then the first... The depth of the drop at the calculated cross section The formula for calculation is: （8）。 7. The method for calculating the breach of a landslide dam according to claim 6, characterized in that: The S505 in the above When the calculated cross section belongs to the broad-crested weir section, then the first... The water flow shear stress at the calculated cross section The calculation formula is: （9） in, The density of water, This is the Manning coefficient; If the first If the calculated cross section belongs to the open channel section, then the first cross section... The water flow shear stress at the calculated cross section The calculation formula is: （10） in, For water density, It is the acceleration due to gravity. For the first The hydraulic radius of the calculated cross section. For the slope.
8. The method for calculating the breach of a landslide dam according to claim 7, characterized in that: The formula for calculating the critical shear stress of water flow in S506 is as follows: （11） in, The critical shear stress of the water flow is... The median particle size of the dam material. For soil density, For water density, It is the internal friction angle; The formula for calculating the erosion function is: （12） in, This represents the actual shear stress of the water flow. The unit transformation factor, and For erosion parameters.
9. The method for calculating the breach of a landslide dam according to claim 8, characterized in that: The formula for calculating the relationship between reservoir capacity and water level in S507 is as follows: （13） in, The reservoir water level elevation is [missing information]. As the benchmark water level, These are the fitting coefficients for the storage capacity curve; The water flow in S508 passes through the first The unit time required for each of the aforementioned calculation sections : （14） No. The depth of the erosion at the calculated cross section The formula for calculation is: （15） Among them, the The calculated cross-sections The second intermediate quantity is calculated as follows: （16） Therefore, the first The elevation of the breach bottom of the calculated cross section. The formula for calculation is: （17） No. The water level elevation of the calculated cross section is （18）。 10. The method for calculating the breach of a landslide dam according to claim 9, characterized in that: In S509, the first The breach width of the calculated cross-section is: （19） No. The slope of the breach side bank of the calculated cross section is: （20） in, For the first The slope of the breach side bank of the calculated cross section. For the first The slope of the breach side bank of the calculated cross section. The initial slope of the breach side bank. and These are the coefficients of the hyperbolic ulcer model; No. When the calculated cross section belongs to the broad-crested weir section, then the first... The breach flow rate at each calculated cross section is: （21） No. When the calculated cross-section belongs to the open channel section, then the first cross-section... The breach flow rate at each calculated cross section is: （22）。