Riverbed sediment particle analysis method and related device

Abstract

The invention discloses a riverbed sediment particle analysis method and a related device, and relates to the technical field of hydraulic engineering and sediment testing.The method comprises the steps that firstly, the light intensity penetrating through a preset plane at each moment in a plurality of moments in the riverbed sediment sample sedimentation process is obtained; the preset plane is any one of the horizontal planes except the highest horizontal plane and the lowest horizontal plane in a sample container filled with the riverbed sediment uniformly-mixed suspension, riverbed sediment with different particle sizes in the riverbed sediment sample settles to the preset plane at different settling speeds, and for each particle size, based on the light intensity penetrating through the preset plane at each moment, the light intensity of the riverbed sediment in the riverbed sediment sample is calculated. Calculating to obtain the percentage of the sand weight smaller than the particle size, based on each particle size and the percentage of the sand weight smaller than the particle size, obtaining the grain composition and the grain composition curve, and further calculating the vertical line average grain composition, the section average grain composition and the section average particle size. According to the method, the particle analysis of the riverbed sediment can be accurately completed.

Description

Technical Field

[0001] The present application relates to the technical fields of water conservancy projects and sediment measurement technologies, and particularly relates to a method for analyzing bed material sediment particles and related devices. Background Art

[0002] In recent decades, the sediment transport volume in the source areas of rivers in many places has shown an increasing trend. In regions such as the Qinghai-Tibet Plateau, the Yellow River, and the Tarim River, the rivers carry different amounts of sediment, which silt up the river channels, causing the riverbed to rise year by year, easily leading to river flooding and meandering, and bringing great difficulties to river channel regulation. The river flow velocity in this area is relatively small, and the sediment deposits and becomes bed material. The sediment in the reservoir area is mostly bed material sediment. The long-term sediment deposition makes the reservoir silt up, shortens the project life, reduces the flood control, irrigation, and power generation capabilities of the project. The sediment will also exacerbate the wear of hydraulic machinery and hydraulic structures, increase the maintenance cost and project cost, etc. Sediment also has its beneficial aspects. Coarse particles are good building materials. Fine-grained sediment can be used for irrigation to improve the soil, turning saline-alkali sandy wasteland into fertile fields. Pumping and silting can reinforce the dike, thus enhancing the flood resistance ability, etc. In order to achieve the purpose of making the best use of advantages and eliminating disadvantages, it is necessary to carry out sediment sampling work, conduct sediment particle analysis and sorting, provide a reliable basis for the development of the basin and national economic construction, and solve the key technical short board of sediment reduction and sediment discharge in the Qinghai-Tibet Plateau reservoir area.

[0003] The main purpose of sampling bed material sediment (i.e., bed sediment) is to conduct particle analysis of bed material sediment, further analyze the cross-sectional lateral distribution and variation of the suspended sediment concentration and the basic sediment transport rate of bed load, and study the basic data of riverbed erosion and deposition changes and roughness. However, the current methods for analyzing the particles of bed material sediment have inaccurate problems. Summary of the Invention

[0004] The purpose of the present application is to provide a method for analyzing bed material sediment particles and related devices, which can accurately complete the particle analysis of bed material sediment.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] In a first aspect, the present application provides a method for analyzing bed material sediment particles, and the method for analyzing bed material sediment particles includes:

[0007] Obtaining the light intensity passing through a preset plane at each of multiple moments during the sedimentation process of a bed material sediment sample; the preset plane is any horizontal plane in a sample container filled with a uniformly mixed suspension of bed material sediment except for the highest horizontal plane and the lowest horizontal plane, the uniformly mixed suspension of bed material sediment is a uniformly mixed sample of bed material sediment and distilled water or a uniformly mixed sample of bed material sediment and salt-free water, and bed material sediment with different particle sizes in the bed material sediment sample settles to the preset plane at different sedimentation velocities;

[0008] For each particle size, based on the light intensity passing through a preset plane at each moment, the percentage of the sediment weight less than the particle size is calculated; the percentage of the sediment weight less than the particle size is the ratio of the sediment content of each particle size less than the particle size to the total sediment content;

[0009] Based on each of the particle sizes and the percentage of the sediment weight less than the particle size, the particle size distribution and the particle size distribution curve are obtained.

[0010] In a second aspect, the present application provides a device for analyzing sediment particles of riverbed material, the device for analyzing sediment particles of riverbed material comprising:

[0011] A light intensity acquisition module, configured to acquire the light intensity passing through a preset plane at each moment among a plurality of moments during the sedimentation process of a riverbed material sediment sample; the preset plane is any horizontal plane in a sample container filled with a uniformly mixed suspension of riverbed material sediment, excluding the highest horizontal plane and the lowest horizontal plane, the uniformly mixed suspension of riverbed material sediment is a uniformly mixed sample of riverbed material sediment and distilled water or a uniformly mixed sample of riverbed material sediment and de-salted water, and the riverbed material sediment with different particle sizes in the riverbed material sediment sample settles to the preset plane at different sedimentation speeds;

[0012] A percentage calculation module, configured to, for each particle size, calculate the percentage of the sediment weight less than the particle size based on the light intensity passing through the preset plane at each moment; the percentage of the sediment weight less than the particle size is the ratio of the sediment content of each particle size less than the particle size to the total sediment content;

[0013] A particle analysis module, configured to obtain the particle size distribution and the particle size distribution curve based on each of the particle sizes and the percentage of the sediment weight less than the particle size.

[0014] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned method for analyzing sediment particles of riverbed material.

[0015] In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the above-mentioned method for analyzing sediment particles of riverbed material is implemented.

[0016] In a fifth aspect, the present application provides a computer program product, comprising a computer program, and when the computer program is executed by a processor, the above-mentioned method for analyzing sediment particles of riverbed material is implemented.

[0017] According to the specific embodiments provided by the present application, the present application has the following technical effects:

[0018] The present application provides a method and related device for analyzing the particles of bed load sediment. The optical analysis method is used to analyze the particles of bed load sediment. Specifically, the light intensity passing through a preset plane at each moment during the sedimentation process of the bed load sediment sample is obtained first. The preset plane is any horizontal plane in the sample container filled with the uniformly mixed suspension of bed load sediment, except for the highest horizontal plane and the lowest horizontal plane. The bed load sediment with different particle sizes in the bed load sediment sample settles to the preset plane at different sedimentation speeds. For each particle size, based on the light intensity passing through the preset plane at each moment, the percentage of the sediment weight less than the particle size is calculated. Based on each particle size and the percentage of the sediment weight less than the particle size, the particle size distribution and the particle size distribution curve are obtained. By introducing the optical analysis method, the present application uses the light intensity passing through the preset plane at each moment during the sedimentation process of the bed load sediment sample to analyze the particles of the bed load sediment, and calculates the particle size distribution and the particle size distribution curve, so as to accurately complete the particle analysis of the bed load sediment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is an application environment diagram of a method for analyzing the particles of bed load sediment provided in Embodiment 1 of the present application.

[0021] Figure 2 It is a schematic flow chart of a method for analyzing the particles of bed load sediment provided in Embodiment 1 of the present application.

[0022] Figure 3 It is a schematic diagram of the analysis results of the bed sediment particles in the Tarilegaka Reservoir Area 2 provided in Embodiment 1 of the present application.

[0023] Figure 4 It is a schematic diagram of the functional modules of a device for analyzing the particles of bed load sediment provided in Embodiment 2 of the present application.

[0024] Figure 5 It is a schematic diagram of the structure of a computer device provided in Embodiment 3 of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0026] Embodiment 1

[0027] The method for analyzing bedload sediment particles provided by the embodiments of the present application can be applied to an application environment as Figure 1 shown. Among them, the terminal communicates with the server through the network. The data storage system can store the data that the server needs to process. The data storage system can be set separately, integrated on the server, or placed on the cloud or other servers. The terminal can send the analysis request to be processed to the server. After receiving the analysis request to be processed, for the analysis request to be processed, the server obtains the light intensity passing through the preset plane at each moment during the sedimentation process of the bedload sediment sample; for each particle size, based on the light intensity passing through the preset plane at each moment, calculates the percentage of the sediment weight less than the particle size; based on each particle size and the percentage of the sediment weight less than the particle size, obtains the particle size distribution and the particle size distribution curve. The server can feedback the analysis result, that is, the particle size distribution and the particle size distribution curve, for the analysis request to the terminal.

[0028] In addition, in some embodiments, the method for analyzing bedload sediment particles can also be implemented by the server or the terminal alone. For example, the terminal can directly process the analysis request to be processed, or the server can obtain the analysis request to be processed from the data storage system and process the analysis request to be processed.

[0029] Among them, the terminal can be, but is not limited to, various desktop computers, laptop computers, smartphones, tablet computers, Internet of Things devices, and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, etc. The portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The server can be implemented by an independent server or a server cluster composed of multiple servers, and can also be a cloud server.

[0030] In an exemplary embodiment, as Figure 2 shown, a method for analyzing bedload sediment particles is provided. This method is executed by a computer device, and specifically can be executed alone by a computer device such as a terminal or a server, or jointly executed by a terminal and a server. In the embodiments of the present application, taking this method applied to the Figure 1 server as an example for illustration, the method includes the following steps.

[0031] Step S1: Obtain the light intensity passing through a preset plane at each of multiple moments during the sedimentation process of the bed load sediment sample. The preset plane is any horizontal plane in the sample container filled with the well-mixed suspension of bed load sediment, excluding the highest and lowest horizontal planes. The well-mixed suspension of bed load sediment is a mixture of well-mixed bed load sediment sample and distilled water or a mixture of well-mixed bed load sediment sample and de-salted water. The bed load sediment with different particle sizes in the bed load sediment sample settles to the preset plane at different sedimentation rates.

[0032] Step S2: For each particle size, calculate the percentage of the sediment weight less than the particle size based on the light intensity passing through the preset plane at each moment. The percentage of the sediment weight less than the particle size is the ratio of the sediment content of each particle size less than the particle size to the total sediment content.

[0033] Step S3: Obtain the particle size distribution and the particle size distribution curve based on each particle size and the percentage of the sediment weight less than the particle size.

[0034] By implementing the above steps S1 to S3, in this embodiment, by obtaining the light intensity passing through the preset plane at each of multiple moments during the sedimentation process of the bed load sediment sample, calculating the percentage of the sediment weight less than each particle size based on the light intensity passing through the preset plane at each moment, and obtaining the particle size distribution and the particle size distribution curve based on each particle size and the percentage of the sediment weight less than the particle size, particle analysis can be completed by optical analysis method, and the particle analysis of the bed load sediment can be completed more accurately.

[0035] In this embodiment, an anti-coagulant is also installed in the sample container, which can prevent the bed load sediment sample from descending in a group in the sample container.

[0036] In this embodiment, the calculation formula for the percentage of the sediment weight less than the particle size is:

[0037]

[0038] where P i is the percentage of the sediment weight less than the i-th particle size; n is the number of particle sizes; D i，i+1 is the particle size between the i-th particle size and the (i + 1)-th particle size; k is the extinction coefficient; L is the thickness of the well-mixed suspension of bed load sediment; I0 is the light intensity at the 0-th moment, that is, the light intensity passing through distilled water or de-salted water; is the light intensity at the moment t i when the bed load sediment of the i-th particle size settles to the preset plane; is the light intensity at the moment t i+1 when the bed load sediment of the (i + 1)-th particle size settles to the preset plane.

[0039] This embodiment can also complete suspended sediment measurement or bed load measurement. Suspended sediment measurement is used for water conservancy projects, river regulation, and soil and water conservation, while bed load measurement is used for reservoir sedimentation and riverbed evolution research, thus facilitating subsequent applications. When the riverbed sediment particle analysis method is applied to suspended sediment measurement or bed load measurement, the riverbed sediment sample is the sample obtained after water sample treatment of the riverbed sediment water sample. The riverbed sediment water sample includes the riverbed sediment water sample of each layer obtained by stratified sampling at each riverbed sediment sampling vertical line for each measurement.

[0040] Among them, the water sample treatment includes: filtering and drying the riverbed sediment water sample to obtain the riverbed sediment sample.

[0041] Among them, stratified sampling refers to sampling at different depths of the riverbed sediment sampling vertical line. When stratified sampling, the calculation formula for the sampling volume of the riverbed sediment water sample is:[[]]

[0042]

[0043] Among them, V is the sampling volume of the riverbed sediment water sample; W min is the minimum sand weight; C is the sediment concentration.

[0044] The riverbed sediment particle analysis method of this embodiment further includes: calculating the vertical average particle size distribution of each riverbed sediment sampling vertical line. The calculation formula for the vertical average particle size distribution is:[[]]

[0045]

[0046] Among them, is the vertical average particle size distribution, d is the particle size; H is the vertical depth; m is the number of layers during stratified sampling; P k (d) is the particle size distribution of the kth layer, that is, the particle size distribution obtained by processing the riverbed sediment sample sampled from the kth layer using steps S1 - S3; Δh k is the sampling thickness of the kth layer.

[0047] The riverbed sediment particle analysis method of this embodiment further includes: calculating the cross-sectional average particle size distribution and cross-sectional average particle size of the cross-section composed of all riverbed sediment sampling vertical lines in each measurement.

[0048] The calculation formula for the cross-sectional average particle size distribution is:[[]]

[0049]

[0050] Among them, is the cross-sectional average particle size distribution; X is the number of riverbed sediment sampling vertical lines; W i is the sand weight per unit width of the ith riverbed sediment sampling vertical line; is the vertical average particle size distribution of the i-th vertical line for bed material sampling.

[0051]

[0052] where D is the maximum particle size; ρ s is the density of bed material sediment; A i (d) is the particle size distribution function of the i-th vertical line for bed material sampling.

[0053] The calculation formula for the cross-section average particle size is:

[0054]

[0055] where D avg is the cross-section average particle size; d max is the maximum particle size; d min is the minimum particle size.

[0056] This embodiment can provide a method for particle analysis of bed material sediment samples obtained by automated sampling of bed material sediment in reservoirs, rivers, lakes, etc., that is, a method for particle analysis of bed material sediment, which can perform particle analysis of bed material sediment scientifically, systematically, efficiently and accurately.

[0057] Hereinafter, taking the application to suspended sediment measurement or bed load measurement as an example, the method for particle analysis of bed material sediment in this embodiment will be introduced in detail. The method for particle analysis of bed material sediment includes the following steps:

[0058] Step 1: Sampling of bed material sediment.

[0059] For particle analysis of bed material sediment, sediment sampling is carried out. During each measurement for particle analysis in suspended sediment measurement or bed load measurement, bed material sediment is taken simultaneously, and the number of measurements can be determined according to user requirements.

[0060] In each measurement, stratified sampling is carried out at each vertical line for bed material sampling. Among them, the vertical line for bed material sampling is in the same position as the vertical line for suspended sediment measurement or bed load measurement. The method for determining the number of vertical lines for bed material sampling is: according to the river width and sediment distribution characteristics, arrange the vertical lines for bed material sampling in accordance with the requirements of the "Regulations for Particle Analysis of River Sediment" (SL42-2010) to cover the main flow zone, shoal and transition zone.

[0061] Step 2: Sampling quantity and sand sample treatment of bed material sediment.

[0062] Calculate the required sampling quantity and treat the sand sample.

[0063] (1) Sampling quantity of bed material sediment samples.

[0064] This embodiment refers to the "Regulations for Sediment Particle Analysis of Rivers" (SL42-2010). For bed sediment, it is usually required that the dry sand weight of each bed sediment sample is not less than 0.1 - 0.5 grams. When sampling, it should be ensured that the bed sediment sample can represent the overall characteristics of the bed sediment, and data deviation caused by too little bed sediment sample should be avoided. At this time, the sampling volume V of the corresponding bed sediment water sample can be calculated according to the sediment concentration C (kg / m3 or g / L) and the minimum sand weight W min Calculate:

[0065]

[0066] The sampling volume of the bed sediment water sample is generally 0.5 - 5 liters.

[0067] (2) Sand sample treatment.

[0068] When analyzing bed sediment samples by the water analysis method, wet bed sediment samples must be used. Except for coarse sand and pebbles that are all analyzed by sieving, dry sand analysis is not allowed. For this reason, the water sample is treated by the replacement method. After the water sample treatment, it can be reserved for particle size analysis. The specific steps of treating the bed sediment water sample by the filtration method and the drying method are as follows:

[0069] ① After sampling, use a standard filter paper or filter membrane to filter the bed sediment water sample to separate the sediment and water. The pore size of the filter paper is usually 0.45 microns. After filtration, put the sediment sample into a sealed container.

[0070] ② Drying: Put the sediment sample into an oven and dry it to a constant weight at 105°C to ensure that all moisture evaporates.

[0071] ③ Weighing: After drying, weigh the weight m of the dried sediment d .

[0072] ④ Calculation: Calculate the dry bulk density ρ of the sediment according to the following formula d .

[0073]

[0074] Among them, ρ d is the dry bulk density of the sediment (unit: g / cm 3 or kg / m 3 ); m d is the mass of the sediment in the completely dry state (unit: g or kg); V is the volume of the sediment (unit: cm3 or m3).

[0075] When concentrating the water sample of bed material sediment, no chemical should be used to accelerate the sedimentation. For the water analysis method, distilled water or demineralized water produced by ion exchange resin must be used. To prevent the bed material sediment sample from descending in a mass during analysis, an anti-flocculant can be added to the concentrated water sample (i.e., distilled water or demineralized water). Generally, 25% ammonia water is used as the anti-flocculant, or other chemicals with better anti-flocculation effects, such as sodium metaphosphate and water glass, can also be added.

[0076] Let the collected water sample of bed material sediment stand for 1 day. If flocculation and subsidence are found, or the upper part of the deposited sediment shows a loose flocculent state, it indicates the presence of water-soluble salts in the water that cause the sediment to descend in a mass. In this case, the following methods can be used for treatment:

[0077] ① Flushing method: Pour the water sample into a beaker, heat it to boiling, and after standing and sedimentation, draw out some clear water, then dilute and precipitate it with hot distilled water, and draw out the clear water again. Repeat this process until there are no water-soluble salts.

[0078] ② Filtration method: Stick a hard filter paper on the funnel, pour the sand sample into the funnel, and then pour in hot distilled water for filtration. During filtration, the liquid level in the funnel should always be 5 mm higher than the sand sample until the filtration of water-soluble salts is completed.

[0079] Step 3: Conduct sediment particle analysis using the optical analysis method in the water analysis method, and calculate the particle size distribution and the particle size distribution curve.

[0080] Based on the particle composition of the bed material sediment, analyze the particle size distribution and draw the particle size distribution curve. The abscissa of the particle size distribution curve is a logarithmic coordinate, representing the sediment particle size, and the ordinate is a probability grid coordinate, representing the percentage of the sand weight less than a certain particle size, including the measurement of the extinction amount and the calculation of the particle size distribution.

[0081] (1) Dynamic monitoring of light intensity attenuation and model construction.

[0082] Put the bed material sediment sample into distilled water or demineralized water, stir evenly to form a well-mixed suspension of bed material sediment. Based on an optoelectronic particle analyzer, continuously monitor the change in light intensity of the bed material sediment sample during the sedimentation process, and construct a quantitative relationship model between the extinction amount and particle characteristics:

[0083]

[0084] where E is the extinction amount; I0 and I are the light intensities after passing through pure water (i.e., distilled water or demineralized water) and turbid water (i.e., the well-mixed suspension of bed material sediment, specifically referring to distilled water or demineralized water containing the bed material sediment sample), respectively.

[0085] (2) Dynamic correlation between the extinction amount and particle parameters.

[0086] The extinction amount E and the sediment concentration C s, the mathematical model between the particle size D and the optical path L is as follows:

[0087]

[0088] Among them, k is the extinction coefficient, which is related to the geometric shape of sediment particles; C s is the sediment concentration of the muddy water; L is the thickness of the muddy water; D is the sediment particle size.

[0089] (3) Dynamic modeling of the sedimentation process in stages.

[0090] ① After the water sample is mixed evenly, at time t1, the sediment with a particle size equal to the first particle size D1 just sinks to the incident light ray (i.e., sinks to the preset plane). At this time, the calculation formula for the extinction amount is as follows:

[0091]

[0092] Among them, is the light intensity at time t1 when the bed sediment with the first particle size sinks to the preset plane; I1, I2..., I i is the light intensity after extinction caused by sediment with particle sizes D1, D2,..., D i respectively. D2 is the second particle size, D i is the i-th particle size; I n is the light intensity after extinction caused by sediment with the smallest n-th particle size D n ; is the extinction amount formed separately by sediment with various particle sizes.

[0093] ② At time t2, all sediment with a particle size greater than D2 sinks below the incident light ray, and the sediment with a particle size of D2 just sinks to the incident light ray. At this time, the calculation formula for the extinction amount is as follows:

[0094]

[0095] Among them, is the light intensity at time t2 when the bed sediment with the second particle size sinks to the preset plane.

[0096] ③ The calculation formula for the light intensity after extinction caused by sediment with a particle size between D1 and D2 is as follows:

[0097]

[0098] Among them, is the extinction amount of sediment with a particle size between D1 and D2; I 1,2 is the light intensity after extinction caused by sediment with a particle size between D1 and D2; C s1,2 is the sediment concentration of sediment with a particle size between D1 and D2; D 1,2 is the particle size of sediment with a particle size between D1 and D2.

[0099] (4) Recursive calculation of the gradation sediment concentration and correction of the extinction coefficient.

[0100] ① The calculation formula for the sediment concentration of sediment with particle size between D1 and D2 is as follows:

[0101]

[0102] ② The calculation formula for the sediment concentration of sediment with particle size between D2 and D3 is as follows:

[0103]

[0104] Among them, C s2,3 is the sediment concentration of sediment with particle size between D2 and D3; D 2,3 is the particle size of sediment with particle size between D2 and D3; is the light intensity at the time t3 when the bed sediment of the 3rd particle size settles to the preset plane.

[0105] ③ The total sediment concentration in the suspension water sample is equal to the sum of the sediment concentrations of various particle sizes, and the calculation formula is as follows:

[0106] C s = C s1,2 + C s2,3 + … + C si,i+1 + … + C sn-1,n ;

[0107] Among them, C si,i+1 is the sediment concentration of sediment with particle size between D i and D i+1 , D i+1 is the (i + 1)th particle size; C sn-1,n is the sediment concentration of sediment with particle size between D n-1 and D n , D n-1 is the (n - 1)th particle size.

[0108] ④ In the well-mixed suspension, the percentage of the sediment weight less than a certain particle size can be obtained by the ratio of the sediment concentrations of each particle size less than a certain particle size to the total sediment concentration:

[0109]

[0110] Among them, P i is the percentage of the sediment weight less than the ith particle size; n is the number of particle sizes; D i，i+1 is the particle size between the ith particle size and the (i + 1)th particle size; k is the extinction coefficient; L is the thickness of the well-mixed suspension of bed sediment; I0 is the light intensity at the 0th moment; is the light intensity at the time t i when the bed sediment of the ith particle size settles to the preset plane; is the time t when the bed sediment of the (i + 1)-th particle size settles to the preset plane i+1 of the light intensity

[0111] Since the known particle sizes D1 to D n and the light intensity at each moment are known, the time when the sediment of each particle size settles to the preset plane can be determined by the existing sediment settlement formula, and thus and the percentage of the sediment weight of the particle size can be calculated. It should be noted that D1 to D n are multiple particle sizes selected according to requirements. There will be other particle sizes between two adjacent particle sizes, so there will be D i，i+1 , which is the particle size between the i-th particle size and the (i + 1)-th particle size

[0112] Step 4: Calculate the vertical average particle size distribution, cross-section average particle size distribution and cross-section average particle size

[0113] Organize the particle size distribution in the optical analysis method, deduce the vertical average particle size distribution, cross-section average particle size distribution and cross-section average particle size of the bed sediment, and the cross-section average particle size distribution curve can also be drawn

[0114] (1) Integral calculation model of vertical average particle size distribution

[0115] Establish a discretized integral model for the bed sediment samples on the sampling vertical line of the bed sediment obtained by the depth-integrating method. Assume that the vertical depth H is divided into m equally divided layers (i.e., sampling layers), and the particle size distribution of the k-th layer is P k (d), then the vertical average particle size distribution is:

[0116]

[0117] where d is the particle size; Δh k is the sampling thickness of the k-th layer, and satisfies

[0118] (2) Vector superposition calculation of cross-section average particle size distribution

[0119] For the calculation of the cross-section average particle size distribution, use the full cross-section mixing method for sampling and particle analysis, and its results can be used as the cross-section average particle size distribution curve. Define that the cross-section consists of n sampling vertical lines of the bed sediment to form a spatial distribution matrix, and establish a vector superposition model based on the sediment weight weight:

[0120]

[0121] where, is the cross-section average particle size distribution; X is the number of sampling vertical lines of the bed sediment; W iis the sediment weight per unit width of the i-th bed material sampling vertical line and is calculated by the following formula:

[0122]

[0123] where D is the maximum particle size; ρ s is the density of bed material sediment; A i (d) is the particle size distribution function (kg / m 3 ·mm - 1) of the i-th bed material sampling vertical line.

[0124] (3) Fractal analysis calculation of the cross-section average particle size.

[0125] ① Discretize the using the Logistic curve, and divide the particle size interval [d min , d max into p geometric series groups:

[0126]

[0127] where d j is the representative value of the particle size of the j-th group; are the upper and lower limits of the particle size of the j-th group respectively.

[0128] ② Establish a grading differential equation:

[0129]

[0130] where ΔP j is the increment of sediment weight percentage (%) corresponding to the particle size of the j-th group, representing the cumulative probability change of the cross-section average particle size grading curve in a specific particle size interval; is the function value of the cross-section average particle size grading function at the upper limit of the particle size of the j-th group; is the function value of the cross-section average particle size grading function at the lower limit of the particle size of the j-th group.

[0131] This differential equation quantifies the proportion of sediment weight in particle size groups through the algebraic difference of the endpoint grading values, providing the core weight parameter for the weighted calculation of the subsequent geometric average particle size.

[0132] ③ Construct a fractal weighted matrix:

[0133]

[0134] where D avg is the cross-section average particle size.

[0135] When ΔP j →0, the equation adopts a continuous integral form:

[0136]

[0137] In this embodiment, and a two - level integration system of vertical line - cross section is constructed, and the operability of actual engineering measurement is realized through spatial discretization processing. The geometric series grouping method is adopted to ensure calculation stability when the particle size span is large. The fractal geometry theory is innovatively introduced. Through exponential weighted average, the particle size distribution characteristics of non - uniform sand are accurately characterized. A traceable mathematical model from microscopic particle analysis to macroscopic cross - section parameters is established for the whole set of algorithms, and a closed - loop calculation chain is formed between each formula through the weight transfer factor.

[0138] This embodiment is used to conduct bed sediment sampling and measurement for a certain reservoir. The water flow velocity of this reservoir is slow and there is sediment deposition. 96.8% of it is bed sediment, which is representative of the particle analysis of the bed sediment in the reservoir area. Through research and analysis, the advantages and positive effects of this embodiment are as follows:

[0139] (1) The scientificity and systematicness of the method for analyzing bed sediment particles. By controlling the sampling amount of sediment samples and applying the optical analysis method, this embodiment can quickly and accurately obtain the particle size distribution. In the measurement of a certain reservoir, the particle analysis results cover the range of 0.002 mm to 2 mm, providing a scientific basis for reservoir silt control and specifically providing reliable technical support for reservoir dredging, river regulation, and ecological environment protection.

[0140] (2) The accuracy of the method for analyzing bed sediment particles. The geometric series grouping method is used to discretize the particle size interval, effectively solving the problem of calculation stability when the particle size span is large. The fractal geometry theory is introduced, and the particle size distribution characteristics of non - uniform sand are quantified through exponential weighted average, enhancing the characterization ability of complex sediment structures. At the same time, the two - level integration system of vertical line - cross section forms a seamless connection between the microscopic particle analysis results (vertical line average gradation) and the macroscopic cross - section parameters (cross - section average particle size) through spatial discretization modeling, forming a full - chain mathematical model from data acquisition to engineering application.

[0141] (3) The efficiency of the method for analyzing bed sediment particles. The closed - loop calculation chain of the weight transfer factor in the algorithm design and the staged dynamic modeling (such as calculating the extinction amount in stages during the sedimentation process) simplify the complexity of actual operation and improve the executability in engineering scenarios. The whole process from stratified sampling to calculating the bed sediment particle size strictly follows industry specifications (such as SL42 - 2010), taking into account both scientific rigor and engineering implementation efficiency.

[0142] Taking the Tarilega Hydropower Station in 2024 as an example, for the measurement frequency layout and sampling operation of the riverbed sediment particle analysis, in the specific implementation process, a macroscopic sediment distribution model of the basin was established through satellite remote sensing image interpretation, and an unmanned ship equipped with a sampling device and an optoelectronic particle analyzer was synchronously deployed to carry out underwater dynamic sampling.

[0143] For the reservoir area, systematic sampling was carried out at the end of the dry season (April 18 - April 20). According to the requirements of the "Regulations for River Sediment Particle Analysis" (SL42 - 2020), within a 30 - km research reach, with the control condition that the change rate of the river channel curvature radius > 15%, 21 characteristic cross - sections were arranged. Five vertical lines for bed sediment sampling were set at each cross - section for stratified sampling, with 1 surface layer sampling, 1 middle layer sampling at 0.5 m, and 1 bottom layer sampling at 1 m. A total of 18 samples were obtained per single cross - section.

[0144] Hydrological parameters were recorded synchronously during the sampling process: flow velocity 0.8 - 1.5 m / s, water temperature 4.2 - 6.8 °C, sediment concentration 0.35 - 1.72 kg / m 3 . The following steps were adopted for sand sample treatment: First, the bed sand particles were filtered; then the bed sand was dried; finally, the dry density of the sediment was determined by the drying and weighing method. The dry density data of the sediment is shown in Table 1 below.

[0145] Table 1 Results of Dry Density of Tarilega

[0146]

[0147] Optical analysis method in the water analysis method was used for sediment particle analysis of the reservoir area bed sand, including light intensity attenuation monitoring, correlation between extinction amount and particle parameters, phased modeling of the sedimentation process, recursive calculation of graded sediment concentration, calculation of the average particle gradation of vertical lines and cross - sections, and fractal analysis of the average particle size of the cross - section.

[0148] The analysis results of the bed sand particles at typical cross - sections (such as the right side of Cross - section 2 in the reservoir area) are shown in Table 2 and Figure 3 , and the results show that the median particle size D50 of the riverbed sediment is 0.056 m, which conforms to the sedimentation characteristics of mountain rivers.

[0149] Table 2 Results of Bed Sand Particle Analysis of Tarilega

[0150]

[0151] The present application also provides an application scenario, which applies the above-mentioned method for analyzing bed load sediment particles. Specifically, the method for analyzing bed load sediment particles provided in this embodiment can be applied to the reservoir treatment scenario. The reservoir treatment scenario includes a particle analysis link and a treatment link. The particle analysis link is used to analyze the bed load sediment particles, and the treatment link is used to treat the reservoir based on the particle analysis results. The method for analyzing bed load sediment particles provided in this embodiment belongs to the particle analysis link.

[0152] Embodiment 2

[0153] Based on the same inventive concept, the embodiment of the present application also provides a device for analyzing bed load sediment particles for implementing the above-mentioned method for analyzing bed load sediment particles. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the device for analyzing bed load sediment particles provided below can refer to the limitations on the method for analyzing bed load sediment particles in the above text, and will not be repeated here.

[0154] In an exemplary embodiment, as Figure 4 shown, a device for analyzing bed load sediment particles is provided. The device for analyzing bed load sediment particles includes:

[0155] An optical intensity acquisition module M1, configured to acquire the optical intensity passing through a preset plane at each of multiple moments during the sedimentation process of the bed load sediment sample; the preset plane is any horizontal plane in the sample container filled with the mixed suspension of bed load sediment other than the highest horizontal plane and the lowest horizontal plane. The mixed suspension of bed load sediment is a mixture of the mixed bed load sediment sample and distilled water or a mixture of the mixed bed load sediment sample and brine-free water. The bed load sediment with different particle sizes in the bed load sediment sample settles to the preset plane at different sedimentation speeds.

[0156] A percentage calculation module M2, configured to calculate, for each particle size, the percentage of the sediment weight less than the particle size based on the optical intensity passing through the preset plane at each moment; the percentage of the sediment weight less than the particle size is the ratio of the sediment content of each particle size less than the particle size to the total sediment content.

[0157] A particle analysis module M3, configured to obtain the particle size distribution and the particle size distribution curve based on each particle size and the percentage of the sediment weight less than the particle size.

[0158] Embodiment 3

[0159] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structure diagram can be as Figure 5As shown in the figure. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a method for analyzing sediment particles on the riverbed.

[0160] Those skilled in the art can understand that Figure 5 the structure shown in the figure is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0161] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, it implements the method for analyzing sediment particles on the riverbed in Embodiment 1.

[0162] Embodiment 4

[0163] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by the processor, it implements the method for analyzing sediment particles on the riverbed in Embodiment 1.

[0164] Embodiment 5

[0165] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by the processor, it implements the method for analyzing sediment particles on the riverbed in Embodiment 1.

[0166] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data that have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0167] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0168] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A method for analyzing riverbed sediment particles, characterized in that: The riverbed sediment particle analysis method comprises: Obtaining the light intensity passing through a preset plane at each of multiple moments in the sedimentation process of the riverbed sediment sample; the preset plane is any horizontal plane except the highest horizontal plane and the lowest horizontal plane in a sample container containing a mixed suspension of riverbed sediment, wherein the mixed suspension of riverbed sediment is a mixed riverbed sediment sample and distilled water or a mixed riverbed sediment sample and non-salted water, and riverbed sediments of different particle sizes in the riverbed sediment sample settle to the preset plane at different sedimentation speeds; For each particle size, based on the light intensity passing through the preset plane at each moment, the percentage of sand weight smaller than the particle size is calculated; the percentage of sand weight smaller than the particle size is the ratio of the sand content of each particle size smaller than the particle size to the total sand content; Based on each of the particle sizes and the percentage of sand weight smaller than the particle size, a particle size distribution and a particle size distribution curve are obtained.

2. The method for analyzing riverbed sediment particles according to claim 1, characterized in that: The calculation formula for the percentage of sand weight smaller than the particle size is: Among them, P i is the percentage of sand weight smaller than the i-th particle size; n is the number of particle sizes; D i，i+1 is the particle size between the i-th particle size and the i+1-th particle size; k is the extinction coefficient; L is the thickness of the mixed suspension of riverbed sediment; I0 ​​is the light intensity at time 0; is the time t when the riverbed sediment of the i-th particle size settles to the preset plane i Light intensity; is the time t when the riverbed sediment of the i+1th particle size settles to the preset plane i+1 light intensity.

3. The method for analyzing riverbed sediment particles according to claim 1, characterized in that: When the riverbed sediment particle analysis method is applied to suspended load test or bed load test, the riverbed sediment sample is a sample obtained after water sample treatment of the riverbed sediment water sample, and the riverbed sediment water sample includes each layer of riverbed sediment water sample obtained by layered sampling at each riverbed sampling vertical line in each measurement; The water sample processing comprises: filtering and drying the riverbed sediment water sample to obtain the riverbed sediment sample; When sampling in layers, the calculation formula for the sampling volume of riverbed sediment water samples is: Wherein, V is the sampling volume of riverbed sediment water sample; W min is the minimum sand weight; C is the sand content.

4. The method for analyzing riverbed sediment particles according to claim 1, characterized in that: The sample container is also filled with an anticoagulant.

5. The method for analyzing riverbed sediment particles according to claim 3, characterized in that: The riverbed sediment particle analysis method further includes: calculating the vertical average particle gradation of each riverbed sampling vertical line; The calculation formula of the vertical average particle size distribution is: in, is the vertical average particle size distribution, d is the particle size; H is the vertical depth; m is the number of layers in layered sampling; P k (d) is the particle size distribution of the kth layer; Δh k is the sampling thickness of the kth layer.

6. The method for analyzing riverbed sediment particles according to claim 5, characterized in that: The riverbed sediment particle analysis method further includes: calculating the cross-sectional average particle size distribution and cross-sectional average particle size of the cross-section formed by all riverbed sampling vertical lines in each measurement; The calculation formula of the average particle size distribution of the cross section is: in, is the average particle size distribution of the cross section; X is the number of vertical lines for riverbed sampling; W i is the sediment weight per unit width of the ith riverbed sampling vertical line; is the average particle size distribution of the vertical line of the ith riverbed sampling vertical line; Where D is the maximum particle size; ρ s is the density of riverbed sediment; A i (d) is the particle size distribution function of the i-th riverbed sample vertical line; The calculation formula of the cross-section average particle size is: Among them, D avg is the average particle size of the cross section; d max is the maximum particle size; d min is the minimum particle size.

7. A riverbed sediment particle analysis device, characterized in that: The riverbed sediment particle analysis device comprises: A light intensity acquisition module is used to acquire the light intensity passing through a preset plane at each of multiple moments in the sedimentation process of the riverbed sediment sample; the preset plane is any horizontal plane except the highest horizontal plane and the lowest horizontal plane in a sample container containing a mixed suspension of riverbed sediment, the mixed suspension of riverbed sediment is a mixed riverbed sediment sample and distilled water or a mixed riverbed sediment sample and non-salted water, and riverbed sediments of different particle sizes in the riverbed sediment sample settle to the preset plane at different sedimentation speeds; A percentage calculation module is used to calculate the percentage of sand weight smaller than the particle size for each particle size based on the light intensity passing through the preset plane at each moment; the percentage of sand weight smaller than the particle size is the ratio of the sand content of each particle size smaller than the particle size to the total sand content; The particle analysis module is used to obtain the particle gradation and particle gradation curve based on each particle size and the percentage of sand weight smaller than the particle size.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the riverbed sediment particle analysis method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for analyzing riverbed sediment particles described in any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for analyzing riverbed sediment particles described in any one of claims 1 to 6 is implemented.

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