Some standard content:
National Standard of the People's Republic of Chinawww.bzxz.net
Specification for Testing Suspended Sediment in Rivers
GB 50159-92
Editor's name: Water Resources and Hydropower Engineering Department of the People's Republic of China Approving Department: Ministry of Construction of the People's Republic of China Date of issue: December 1, 1992
Notice on the promulgation of the national standard "Specification for Testing Suspended Sediment in Rivers"
Construction Standard [1992] No. 516
According to the requirements of the State Planning Commission's document [1986] 250 and the Ministry of Construction's document [1991] 1727, the "Specification for Testing Suspended Sediment in Rivers" jointly formulated by the Ministry of Water Resources and other relevant departments has been reviewed by relevant departments. The "Specification for Testing Suspended Sediment in Rivers" GB 50159-92 is now approved as a mandatory national standard. It will be promulgated on December 1, 1992 This standard is managed by the Ministry of Water Resources, and its specific interpretation and other work are the responsibility of the Hydrological Bureau of the Yellow River Conservancy Commission of the Ministry of Water Resources, and the Standard and Quota Research Institute of the Ministry of Construction is responsible for the publication.
Ministry of Construction of the People's Republic of China
August 10, 1992
Preparation Instructions
This standard is based on the requirements of the National Planning and General [1986] No. 250 document, and is edited by the Hydrological Bureau of the Yellow River Conservancy Commission of our Ministry and jointly compiled with relevant units.
In the process of compiling this standard, the standard compilation team conducted extensive investigations and studies, carefully summarized the practical experience of sediment measurement in my country's river transport, referred to relevant international standards and advanced foreign standards, carried out scientific research and experimental verification on major technical issues, and widely solicited opinions from relevant units. Finally, our Ministry and relevant departments reviewed and finalized the draft.
This specification is compiled for the first time. During the implementation process, we hope that all units will combine engineering practice and scientific research, seriously summarize experience, and pay attention to accumulating information. If you find that there are places that need to be modified and supplemented, please send the opinions and relevant materials to the Hydrological Bureau of the Yellow River Conservancy Commission of our Ministry (No. 2 Chengbei Road, Zhengzhou City, Henan Province, Postal Code: 450004): for reference in future revisions.
Ministry of Water Resources of the People's Republic of China
January 1992
Chapter 1
Chapter 2
Section 1
Book 2
Section 3
Chapter 3
Section 1
Section 2
Section 3 ... ||Section 1
Section 3
Section 4
Section 5
Section 6
Chapter 5
Section 1
Selection and operating requirements of suspended sediment testing instruments Technical requirements for instruments Applicable conditions for different suspended sediment testing instruments Operating requirements for instruments Suspended sediment transport rate and particle grading test General provisions Suspended sediment transport rate and particle grading test Distribution of particle size distributionTest method for suspended sediment rate
Sampling method for suspended sediment rateSampling method for particle size distributionCorresponding sample selection
Determination of sand transport in sandy riverbed by indirect methodError source and control of sand transport…
Single sample sand content test
General provisions
Distribution of single sample sand content test
Single sample particle size distribution test zone
Single sample sand content identification method…
Single sample Suspension and detection of gold containing sand
Sources of error and control
Sediment test under sandy flow conditions
Sediment-containing gold and particle size distribution test
9—10
Section 1 Determination of rheological properties
Observation of debris flow, muddy river and exposed river bottom
Chapter 6
Processing of suspended sediment water samples·
Section -
Section 1
General provisions
Drying method.
Section 1
Retention method
V. Sources of error and control
Chapter E
Calculation, inspection and analysis of suspended sediment test data
Calculation of measured sediment content
Section 1
Section 2
Calculation of sediment transport rate and average sediment content in a certain period of time, and rationality inspection of measured results
Section 3|| tt||Section 4
Analysis of suspended sediment transport rate test method Section 1
Analysis of simplified particle grading sampling method
Section 6
Section 7
Chapter 8
Analysis of single sampling position -
Interval analysis of suspended sediment transport rate and particle grading Estimation of uncertainty in suspended sediment test
Section 1
Chapter. Section
Section 3
Section 4
Attached—
Appendix King
General provisions,
9—12
9—1 3
9—14
9—15
9—16
9—16
9—17
9—17
9—18
9—19
9—19
: 9—20
: 9—21
... 9—-21
9—22
9---22
Suspended sediment test error composition and collection of required data 9-22 Estimation and control index of sub-item uncertainty Estimation of total random uncertainty and systematic uncertainty Equipment and operation of suspended sediment sample treatment 9—23
9—25
Format of report form and filling instructions for suspended sediment test 9—28 Test method for rheological characteristics of high-sediment flow
Terminology used in this specification
Additional instructions
. 9-38
. 9—45
Chapter 1 General
Article 1 This specification is formulated to specify unified methods and technical requirements for the measurement of sediment transport rate, sediment content and particle size distribution of rivers and the estimation of uncertainty in suspended sediment measurement, so as to make the measurement of suspended sediment technically advanced and economically reasonable and provide reliable basic data for river construction. Article 1-0.2 This specification is applicable to the measurement of total sediment transport at national basic sediment stations, hydrological experimental stations and special stations.
Article 1-0.3 The classification of national basic sediment stations shall comply with the following provisions: Classification stations are stations for the main sediment producing areas. , stations that play an important role in the design and management of major engineering sections, river management or riverbed evolution research; Class I stations are general control stations and key regionalized stations; Class III stations are general regionalized stations and small river stations. Article 1.0.4 The test items and requirements of each type of station shall comply with the following provisions: Class I stations shall measure the sediment transport rate, sediment content and the particle size distribution of total sediment and bed sand. The test accuracy shall be higher than that of Class XII and Class III stations, and a long series of annual tests shall be carried out. Some Class I stations may use direct or indirect methods to conduct full sand transport rate tests or conduct river section measurements as needed; Class II and Class III stations Suspended sediment transport rate and sand content should be measured. Most Class II stations should measure the suspended sediment particle gradation. The test accuracy can be as high as that of Class III stations. Class II stations should measure suspended sediment transport rate and sand content. Some Class II stations should measure suspended sediment particle gradation. The test accuracy can be lower than that of Class III stations. Class II stations, Article 10.5 The national basic sediment station shall comply with the following provisions when conducting total sediment transport patrols:
, if a single-sediment relationship has been established, patrols can be carried out during the non-flood season. During the period, there should be people stationed at the station or an automatic sand measuring device should be used to conduct single-sample sand content tests. The distribution of the test can control the change process of the sand content base, patrol sediment transport When measuring the rate, the single sample content test method and the single-section sediment relationship should be checked;
2. For stations where the relationship between flow and discharge rate is relatively stable, only the discharge rate can be measured, and the distribution of sediment rate measurements should meet the requirements for data compilation.
Article 1.0-6 The suspended sediment axial flow rate and particle grading tests of Class II and Class III stations can be carried out through inter-measurement when they meet the inter-measurement conditions in Chapter 7, Section 7 of this Code. Article 1.0.7 The suspended sediment and mud test, in addition to implementing this Code, should also comply with the relevant provisions of the current national standards "Standards for Hydrological Measurement Terms and Symbols", "Water Level Observation Standards" and "River Flow Measurement Codes". 9—4
Chapter 2 Selection and Operation Requirements of Suspended Sediment Testing Instruments Section 1 Technical Requirements for Suspension Sediment Testing
Article 2.1.1 All types of time-accumulation type samplers shall comply with the following provisions: 1. The instrument shall be streamlined in shape, and the nozzle water inlet shall be located at a place where the water flow disturbance is small. When sampling, the pressure inside the instrument shall be balanced with the hydrostatic pressure outside the instrument; 2. When the river flow velocity is less than 5m/s and the sand content is less than 30kg/m, the nozzle inlet velocity coefficient shall be between 0.9 and 1.1 should be greater than 75%, when the sand content is 30-100kg/m. The guarantee rate of the nozzle inlet velocity coefficient between 0.7 and 1.3 should be greater than 75%:
3. The sample volume of the instrument should be able to adapt to the sampling method and indoor analysis requirements, and a longer sampling time can be used to reduce the impact of sediment pulsation; 4. The instrument should be able to obtain water samples close to the river bed surface. For instruments used in wide and shallow rivers, the height from the water inlet nozzle to the river bed surface should be less than 0.15m:
5. When various mixed methods are used for sampling, the instrument should be able to reduce the sand accumulation at the nozzle. 6. The instrument should be simple in design, firm in structure, reliable in operation, easy to maintain, and the instrument can be removed for washing.
Article 2.1-The main recording sampler shall meet the following requirements: 1. The inner wall of the instrument shall be smooth and free of traces; 2. The two ports of the instrument shall be kept closed synchronously and not slippery; 3. The volume of the instrument shall be accurate; 4. The longitudinal axis of the instrument body shall be parallel to the longitudinal axis of the lead fish and shall not be affected by the water blocking of the calcium fish. Article 2.1.3 The field sand measuring instrument shall meet the following requirements: 1. The working curve of the instrument shall be relatively stable, and it shall be able to self-correct for the influence of water temperature, mud particle shape, particle composition and chemical characteristics, or the error shall be controlled within the allowable range; 2. When measuring the sediment content, the stability and reliability of the instrument shall not be lower than that of the cumulative sampler; 3. The instrument shall remain stable during continuous operation; 4. The calibration of the instrument shall be reliable and the measurement frequency shall be low; 5. The instrument can reliably measure the sediment content close to the riverbed; 6. The instrument shall be easy to install, operate and maintain. Section 2 Applicable conditions of different suspended sediment testing instruments Article 2·2·1 Pressure-regulated samplers are applicable to point-selection and mixed sampling when the sediment content is less than 30 kg/m. Article 2·2·2 Bag-type samplers are applicable to depth-collection, point-selection and mixed sampling under different water depths and sediment content conditions. Article 22.3 Ordinary bottle samplers are applicable to two-way depth-collection and manual sampling at a water depth of 1.0 to 5.0 m. Article 2·2·4 Horizontal samplers can be used for sampling under different water depths and sediment content conditions, but are not applicable to continuous sand measurement and should not be used when the accuracy requirements are high. Article 2·2·5 Recording isotope sand measuring instrument is applicable to point-selection sand measurement when the sediment content is less than 20 kg/m.
Section 2 Operation requirements of instrument
Article 2·3·1 Various samplers should be inspected before use. During the test, if any problems are found, the causes should be promptly identified and handled. After sampling, except for replacing the whole selection container or measuring the storage volume on site, the water sample volume should be recorded on site, and the sample container should be rinsed clean. Article 2.3.2 When using the accumulation time sampler and the accumulation depth method to collect samples, the following provisions shall be met: First, the sampling instrument should be raised and lowered at a constant speed; Second, when the water depth is less than or equal to 10m, the lifting and lowering speed should be less than 1/5 of the average flow velocity under the vertical line; when the water depth is greater than 10m, the lifting and lowering speed should be less than the vertical line. 1/3 of the average flow rate of the line;
3. When sampling by the accumulation depth method, the water depth of the first-class station should not be less than 2.0m, and the water depth of the second and third-class stations should be greater than 1.0m
4. When the receiver is in the open state, it shall not stay on the riverbed; 5. The suspension method of the receiver shall ensure that the water inlet nozzle of the instrument is facing the flow direction 6. The ratio of the sampling volume of the receiver to the volume of the instrument water sample chamber and the reduced-sensitivity sample container shall be less than 0.9. When the receiver is found to be full: the water sample taken shall be discarded and retaken. Article 2.33 When sampling with a horizontal sampler, the following provisions shall be met: 1. When the water depth is large: the instrument shall be suspended with a lead fish; 2. When sampling with a hammer switch, the instrument must be lifted after the instrument is turned off:
3. Before pouring the water sample, you should stop for a while to prevent the outside of the instrument from bringing water into the water sample. Article 2.3.4 When sampling with an ordinary bottle sampler, the following rules shall be met: 1. When the vertical half-average flow velocity is less than or equal to 1.0 m/s, a water inlet nozzle with a pipe diameter of btmm shall be selected;
2. When the vertical half-average flow velocity is greater than 1.0m/s, a water inlet with a diameter of 4mm should be used;
Third, the diameter of the exhaust pipe of the device should be smaller than the diameter of the water inlet nozzle. Article 2.3-5 The fruit picking is measured with an isotope meter and shall comply with the following provisions: 1. Before using the instrument, the working curve should be calibrated: 2. When measuring sediment content, the distance from the instrument probe to the water surface and the river bottom shall not be less than the detection radius of the radioactive source;
3. During the use of the instrument, the working curve should be calibrated regularly with an integral time sampler. When the relationship points of the previous and subsequent calibrations deviate from the original working curve by less than or equal to 2%, the original working curve can continue to be used. When it exceeds 2%, the working curve should be re-determined.
Chapter 3 Suspended sediment transport rate and particle grading test Section 1 General provisions
Article 3.1.1 When different suspended sediment transport rate test methods are used to determine the average sediment content of the section, they must meet the partial flow weighted principle and accuracy requirements. Article 3.1.2 The work content of suspended sediment transport rate test shall comply with the following provisions:
1. Arrange velocity and sediment measuring vertical lines, measure the starting point distance and water depth on each vertical line, measure the flow velocity on the velocity measuring vertical line, and take water samples on the sediment measuring vertical line. The sand measuring vertical line should coincide with the velocity measuring vertical line;
2. Observe the water level and water surface gradient. When the water sample needs to be analyzed for particles, the water temperature should be measured:
3. When it is necessary to establish a single-section relationship, the corresponding single sample should be taken: 4. When the buoy method is used to measure the flow or the full-section mixing method is used to measure the sediment transport rate, water samples are only taken on the banknote measuring vertical line.
Article 3·1·3 Various test methods for determining the average particle size distribution of suspended sediment must comply with the weighted principle and accuracy requirements of the sediment transport rate. Section 2 Article 3·2·1 "The distribution of the total sediment transport rate and particle size distribution measurements in one year should be distributed during the flood period and comply with the following provisions:
1. When the cross-section average combined flow process line method is used for data compilation, the annual measurement frequency should follow the whole process of controlling the maximum change of sand content. The measurement frequency for each change of flood peak should not be less than 5 times. In the flat and sticky water period, the first-class station should measure 5-10 times a month, and the second and third-class stations should measure 3-5 times a month. When the single cross-section relationship line of the second and first-class stations in previous years is compared with the comprehensive relationship line of previous years, and the change is within ±3%, the annual measurement frequency should not be less than 15 times. When the second and third-class stations are compared in the same way, and the change is within ±5%, the annual measurement frequency should not be less than 10 times. When the change is within 2% over the years, the annual measurement frequency should not be less than 6 times, and the annual measurement frequency should be evenly divided into cities within the range of sand content variation. Internal:
3. When the single-break sand relationship line is divided into two or more relationship curves according to the water level or time period, the annual total load sediment transport rate measurement frequency should not be less than 25 times for Class I stations, and not less than 15 times for Class I and Class III stations. The measurement frequency should be distributed at the turning point of the relationship curve; 4. When the single-break sand relationship ratio coefficient process line method is used to compile data, the measurement frequency should be evenly distributed and the turning point of the ratio coefficient should be controlled. The measurement frequency should be distributed at the important turning point of the flow plate and the sediment content;
5. When the flow-sediment transport rate relationship curve method is used to compile data, the annual measurement frequency distribution should be able to control the change process of each major flood peak. A small number of measurements should be distributed in the half-water and dry seasons. Article 3.2.2 The suspended sediment transport rate measurement frequency of weirs, reservoir stations and tidal stations should be appropriately distributed according to the changes in water level, sediment content and data compilation requirements.
The new station should increase the number of sediment transport rate measurements within the first three years. Article 3.2.3: The number of measurements for determining the average particle size distribution of the section within a year should be mainly distributed in the flood season and should comply with the following provisions: 1. When using the cross-section average particle size distribution process line method for data compilation, the second-class station and the annual measurement should be able to control the particle size distribution change process. Each large flood peak should be measured 3 to 5 times, and the flood season should not be less than 4 times a month. In the non-flood season, the sandy rivers should be measured 2 to 3 times a month, and the sandy rivers should be measured 1 to 2 times a month;
2: The relationship line between the single-sample particle size distribution of the first-class station and the average particle size distribution of the section (hereinafter referred to as the single-section particle size distribution relationship line) and the comprehensive relationship line over the years are compared. The coarse sand part When the change is within ±2% and the change of fine sand is within ±4%, the annual measurement frequency should not be less than 15 times. For the Class II station, the same comparison is made. When the change of the coarse part is within ±3% and the change of the fine part is within ±6%, the annual measurement frequency should not be less than 10 times. 3. When the single-break particle relationship line is divided into two or more relationship curves according to the water level or different time periods, the annual measurement frequency should not be less than 20 times for Class I stations and 15 times for Class II stations. 4. For stations with scattered single-break particle relationship points or newly carried out particle grading tests, the measurement frequency should be increased accordingly.
5. Class II stations should measure 5 to 7 times in flood season and 2 to 3 times in non-flood season. The monthly and annual average particle grading can be ignored. Section 3 Test method for mobile sediment transport rate
Section 3.3.1 The test method for mobile sediment transport rate should be determined based on the characteristics of the measuring station, accuracy requirements and equipment conditions. Article 3·3·2: The method of laying out the sediment transport rate vertical line and the number of vertical lines shall be determined by test analysis. Before test analysis: the single-width sediment transport rate turning point wiring method can be used. The number of vertical lines for sediment measurement should not be less than 10 for Class I stations, not less than ? for Class II stations, and not less than 3 for Class III stations.
Article 3·3·3: When the suspended sediment transport rate test is carried out at the same time as the flow rate, the vertical line sampling method can adopt the point selection method, the depth accumulation method and the vertical line mixed method, and shall comply with the following provisions:
When the point selection method is adopted, the flow velocity at each point should be followed at the same time. The measurement point locations of various point selection methods shall comply with the provisions of Table 3·3·3-1. Measuring point locations of various point selection methods
Test situation
Test method name
No point selection
Three-point density
Three-point land
One-point summary
Six-point method
Three-point method
One-point drinking
Relative data position of measuring points
Water system, 2, 0.5, 0.B I A Ni
0.2, 0.6.0.8
0.2, u.8
Table 3 + 3 - 3-1
Ice bottom or ice flower village. 0.2, 0.4, 0.6, 0.8, 0.15, 0.85
Let: The relative water course is the ratio of the machine course to the vertical line water course. In the ice period and depression, the relative water depth should be the effective relative water. When using the accumulation depth method, the vertical average flow velocity should be measured at the same time. 3. When the vertical line mixing method is adopted, the average vertical velocity should be measured in time, and the following provisions should be met:
1. When sampling is mixed according to the sampling duration ratio, the sampling position and duration of various sampling methods shall comply with the provisions of Table 3.3 and 3-2. The sampling position and duration of various sampling methods are as follows:
Three-point land
Two-point iron
Relevant water details of sampling
Water surface, 0.2, 0.6, 0.8, and river bottom
0.2. 0.6. n.8
Total fresh water duration of fire burning
Table 3-3-2
Time for sampling at each point
0.11, 0.3. 0.5t. D.21, 0.11
1 173 +/ 3. 1/3
0.5t, 5t
2.When sampling and mixing by volume ratio, the sampling method shall be determined by test analysis. Article 3.3.4: For stations with single-section and deep water in the test section, the equal partial water surface width and full section mixing method can be used to test the suspended sediment transport rate. The instrument lifting and lowering speed and instrument water inlet pipe inspection of each vertical line using the accumulation depth method should be the same, and the wiring should be based on the center of the partial water width.
Article 3.3-5: For stations with rectangular sections sampled by fixed vertical lines, the equal partial area and full section mixing method can be used to test the suspended sediment transport rate. Each vertical line should use the same water inlet nozzle, sampling method and sampling milk, and the partial area represented by each step should be equal.
When the partial areas are not equal, the sampling duration of each vertical line should be allocated according to the weight coefficient of the partial area.
Article 3.3-6: For stations with relatively stable sections, the equal partial flow to full section mixing method can be used to test the suspended sediment transport rate. The water accumulation of each vertical level and the partial flow rate it represents should be equal
When the average sediment content of a certain type of station is determined by the sediment transport rate test method in Article 3·3-7, after experimental analysis, the allowable error of the vertical line selection method and the heavy line layout should not exceed the provisions of Table 3·3·7.
· Class station
Second class station
Third class station
Measurement method and allowable difference in photography layout
Auspicious assistance items
Health fee (%)
Vertical layout
Relevant standards
Combined (%)
Receiving sample missing
System frequency recognition disk (%)
Main suspension sand
Relatively small part
Need for heavy line layout
Drinking cardamom (%)
All sensitive parts
Article 33-8||t t||Some stations in the first category and representative stations in the second and third categories should conduct precision tests on the suspended sediment transport rate test method. Section 4
Sampling method for suspended sediment transport rate and particle size distribution. When using suspended sediment transport rate test water samples for particle analysis, the following provisions should be met:
..-, when using the velocity meter method to measure at any time, the suspended sediment transport rate test water sample can be used as the subject particle analysis, or another water sample can be taken for particle analysis on the same sand measurement vertical line; in addition, various new data determined by test analysis can also be used as the sampling method for sediment transport rate particle size distribution. Before test analysis, the number of sampling vertical lines for the full section filtration method should not be less than 5 for the first category station, and 2. The three types of stations should not be less than 3 items. Article 3.4.2: For the first type of stations and the second and third type of stations to be tested, the five-point method should be used to conduct 2 to 3 sediment transport rate tests on 710 vertical lines every year. Each time, the bed sand and water temperature should be added to the test bed, and particle analysis should be performed. Article 3.4-3: The accuracy of the particle grading sampling method for the suspended sediment transport rate of each type of station should be tested and verified. The uncertainty of the absolute error of the cumulative weight percentage of each particle size grade on the cross section: 1. The second type of station should be less than 6, and the third type of station should be less than 9. The systematic error of each station shall be within 12.0% for the coarse sand part and within ±3.0% for the fine sand part.
The tests and data analysis of each station shall be conducted in conjunction with the accuracy test of the total sediment transport rate test method.
Section 5 Collection of corresponding single samples
Article 3-5-1 For stations that use single-section sand or single-section trace data compilation, corresponding single samples shall be taken at the same time as the sediment transport rate test. Article 3.5.Z The sampling method and instrument for corresponding single samples shall be the same as those for regular single sample tests.
For sediment transport rate measurements that are also used for particle analysis, water and salt shall be observed at the same time. When the single sample sand content sampling method and the single sample sampling method are alternated, the corresponding single sample can be used for particle analysis; when not, a water sample shall be taken for particle analysis. Article 3·5·3 The sampling frequency of the corresponding single sample should be taken when the water situation is stable: when there is a slow change, it should be taken at the beginning and end of the sediment transport rate test; when the water and sand change dramatically, the sampling frequency should be increased, and the non-control turning changes should be avoided. Section 6 Determination of the total sediment transport rate by indirect method in sandy riverbeds Article 3·6·1 Record the design of a type of station and important water conservancy project that requires full sand measurement in sandy riverbeds. Stations that require full sand data for management and riverbed evolution research shall use the indirect method to determine the total sediment transport rate:
Article 3·6·2 When using the indirect method to determine the total sediment transport rate, the total mobile sand rate should be calculated and the taste should be measured. Water temperature and water surface gradient, and sediment particle analysis should be performed.
Article 3·6·3 The frequency of measurement of individual sand dunes by the indirect method shall be 10 to 15 times per year during the flood season, and a full sand dunes data compilation shall be conducted every three years.
Section 7 Sources of Error and Control
Article 3·1·1 The systematic error produced by the test method shall be controlled in accordance with the following provisions:
When a Class I station adopts the vertical line injection according to the volume ratio, the results shall be tested and analyzed. When the identification error exceeds the allowable standard. The line sampling method should be improved: 2. For the transmission rate test of Class I stations, the one-point method shall not be used except when the water depth is less than 0.75m;
3. When the Class I station is tested by the five-point method, the lowest point can be placed at a relative water depth of 0.95 if there is no test data to prove it; 4. When the Class I station adopts the accumulation depth method for sampling, the distance from the instrument water inlet nozzle to the river bottom should not exceed 5% of the vertical line water depth;
5. When the lateral distribution and interruption of the content change significantly, the data should be analyzed in time to adjust the position of the measuring vertical line and the number of vertical lines. Article 3-7·2 Systematic errors caused by testing instruments and operating techniques should be controlled in accordance with the following provisions:
Horizontal samplers should not be used in this type of station;
2. When the deflection angle exceeds 30", the accumulation method should not be used for sampling; 3. When using an accumulation sampler, the inlet flow rate of the instrument should be checked regularly. If it is found to be significantly too large or too small, the cause should be found out and handled in time; 4. Under various test equipment conditions, it should be ensured that the instrument can be accurately placed at the sampling position:
When using ordinary bottle samplers for continuous sand measurement, it is advisable to use manual operation for two-way accumulation depth;
6. When sampling with an accumulation sampler, the pipe should be checked and cleared. Article 3·7·3 Article 4.1-1 The method of testing the single sample sediment content should be able to make the proportional coefficient of the single-break sediment relationship line of the Class II station between 0.95 and 1.05, and that of the Class II and Class III stations between 0.93 and 1.05.07,
Article 4.1-2 When the single sample is also used as a water sample for particle analysis, the sampling method should meet the requirements of the average particle size distribution of the cross section. When the single particles are more skewed or finer than the cross section: the sampling method of the single sample should be improved, or the single particle sampling method should be determined. Article 4.1.3 The sampling of single samples should include the following: 1. Observe the basic water level;
2. Measure the starting point distance of the sampling vertical line;
3. Measure or calculate the vertical line water depth;
4. Sampling according to the determined method:
5. When the single sample needs to be analyzed for particle size, the water temperature should be measured. Section 2 Distribution of the number of measurements of single sample sediment content test Article 4.2.1 The distribution of the number of measurements of the sediment content of a single sample within a year should be able to control the change process of the sediment content and meet the following regulations: 1. During the flood season, each major flood should not be less than 8 times for Class I stations, 5 times for Class II stations, and 3 times for Class III stations. When the flood peak is heavy, the water and sediment are not consistent, or the sediment content changes dramatically, the number of measurements should be increased. The number of measurements should be distributed at the turning point of the sediment content change:
"2. During the flat water period of the siltation period, samples should be taken at regular water level observations. When the sediment content changes slowly during the non-flood season, Class I stations can take samples every 2 to 3 days, and Class II stations can take samples every 5 to 10 days.
3. When there is a periodic daily change in the sediment content, it should be determined through experiments to take samples at representative times. | |tt||Article 4·2-2 Weir and reservoir stations should appropriately distribute measurements and modifications according to the changes in gate 1 and sediment content to control the change process of the total sediment content. Article 4·2-3 Tidal current stations should determine the frequency distribution of single sample sediment content measurements according to the station establishment date, requirements and test conditions. Section 3 Frequency distribution of single sample particle size distribution Article 4·3·1 For Class I and Class II stations that need to conduct single sample particle analysis, the particle size measurements should be distributed in the flood season, and a small number of measurements should be distributed in the non-flood season to control the change process of sediment particle size distribution, and should comply with the following regulations: 1. During the flood season, each large flood peak should be analyzed 3 to 7 times, and particle size measurements should be distributed at the turning point of flow and sediment content changes;
2. During the normal water period of the flood season, the river should be analyzed 5 to 7 times more often, and less frequently. Sandy rivers can be analyzed once every 10 days;
Third, in the non-flood season, sandy rivers can be analyzed once every 7-10 days, and sand-free rivers can be analyzed once every 15 days. When single samples are mixed with accumulated water samples, they are analyzed with accumulated water samples:
At the same time, the sediment transport rate measurements and their corresponding single samples selected for particle analysis should all be subjected to particle analysis.
Chapter 4·3-2: If there are no special requirements for Class III stations. Sampling and analysis are only performed 1 to 3 times during each flood process during the flood season each year. Analyze 2 to 3 times when necessary in the non-flood season. Section 4·4·1 The vertical line layout for the single sample sediment content test has been determined through experiments and meets the following requirements:
. For stations with relatively stable cross-sections and no soil flow swings, Use fixed sampling vertical line positions and analyze and determine according to the provisions of Article 7.6.1 of this Code. When there are large changes in the lateral distribution of sand content in complex rivers or different water levels, the joint sampling positions of representative lines should be determined according to different water levels:
2. For "type 1" stations with unstable sections and movable soil and beach, 3 to 5 sampling lines should be laid out according to the conditions of the measuring station and the provisions of the full section and mixed method to conduct single sample horizontal test.
Article 4.4.2 The vertical sampling method of single sample horizontal test should be consistent with the vertical sampling method of sediment transport rate test and meet the following requirements: 1. For single sample sand content test of type 1 stations, the point method shall be adopted: 2. When the single sample is also used as a water sample and cannot meet the accuracy requirements: the single particle sampling method shall be determined separately for the test.
Article 4-4.3 Single sample shall be taken in special circumstances, and the following regulations shall be followed: 5 [extended distance: flood requirements. During the period of ice and full timber, it is not possible to collect samples at the selected location. You should leave the shore and collect samples at normal water shortage places with notes. The sampling results at the waterside should be related to the average sand content of the section: 2. For the sections with separate water gauges, the sampling positions should be selected as independent sections.
Section 5 Suspension measurement and visual inspection of single sample sand content Article 4.5.1 - Class stations and stations that need single sample sand content data in the dry season should conduct single sample sand content measurement every year. For other stations, when the sediment discharge during the dry season for more than three consecutive months is less than 3.0% of the multi-year average sediment discharge, the single sample sand content and the vertical sand content should be used during the hours, and the combined sand during the floating measurement period should be counted as zero. Article 4-5.2 When the sediment content is less than 0.0Skg/㎡, water samples of equal time intervals and volumes can be accumulated and mixed to serve as the single sample sediment content of Qichuan during the cumulative supply period. The cumulative period should not cross months or years. When the sediment content of the water has obvious changes, stop the accumulation. Article 4-5.3 During the sediment content measurement period, when the water of Mahe River is clear, it can be collected for measurement and the sediment content can be treated. When the sediment content has increased significantly, it should be measured in time.
During flood and flat water period, estimation methods such as colorimetric method, sediment product quotient method, simple guide gravity method and simple replacement method can be used to estimate the sand content and determine the sampling time for additional measurement, suspension measurement and rapid re-measurement.
Section 6 Sources and Control of Error Adjustment
Article 4.6.1 The test error of sand content of a single sample, including the comprehensive error of a single test and the error of insufficient distribution of measurements, shall be controlled in accordance with the following provisions: 1. Single full test error. Mainly comes from the vertical line layout, vertical line sampling method, instrument performance, operation technology and water sample treatment. In addition to strictly implementing relevant regulations, the position of the sampling vertical line should always pay attention to the changes in the lateral distribution of sand content and the relationship between single-section sand. When obvious changes are found, the vertical line position should be adjusted in time; when there are large tributaries joining the section upstream or there is a possibility of abnormal flow in the river channel, the number of vertical lines should be appropriately increased or the number of measuring points on the vertical line close to the bottom should be increased: 2. Distribution of measurements. When the flood composition is complex and the water and sand peak process is inconsistent, in addition to filling according to the water level turning point, a simple method should be used to estimate the sand content, grasp the turning point of the change in sand content and take samples in time; 3. When sampling must be carried out near the water due to special difficulties, the influence of collapsed banks or other abnormal water flows should be avoided to ensure that the water sample is representative. Article 4-6.2 When engineering construction or sand dredging, gold panning, etc. are carried out upstream of the section, causing localized sedimentation, the source of the sediment and the scope of the affected river section should be promptly identified, and the situation should be noted in the records and compiled materials. Chapter 5 Sediment Testing under High-Sediment Flow Conditions Section 1 Sediment Penetration Gradation Test
Article 5.1.1 For section average sediment content testing, Class I stations can adopt the full section grip method, Class II and Class III stations can adopt the stream edge half-depth point method or the accumulation depth method, and Class II stations can adopt mainstream edge sampling when they meet the accuracy requirements after testing. The sediment sampling method can also be used as the gradual average particle size distribution sampling method. Article 5-1-2 During floods, the sediment content card test times are based on the specification in Section 4. -2-1 shall increase the number of particle size measurements by 3 to 5 times accordingly. For each major flood peak, the first-class stations shall conduct no less than 15 measurements, and the second-class stations shall conduct no less than 3 measurements.
Article 5.1.3 When the sediment content is high, a horizontal sampler can be used for sampling, and no repetition is required. When an integral sampler is used, the inlet pipe end with a large diameter shall be used, and the inlet velocity coefficient shall be used as a limitation. In special circumstances, other samplers may be used. Article 5.1.4 Water with high sediment content often contains coarse sediment. When determining the sediment content and the grading of the sand particles, all the coarse particles must be included. Section 2 Determination of rheological properties
Article 5.2-1 In rivers with high sediment content, some important control stations shall be selected as needed to take water samples for the determination of rheological properties within a certain period of time. Article 5-2-2 During each major flood, When the water is wet, use the method of measuring the sand content, and take 2 to 3 water samples for rheological properties test. The volume or weight of the sample should be determined according to the needs of the test items.
Article 5·2·3 The sample for the rheological properties test should be kept as it is. When it is difficult to keep it as it is, the measuring station should put the wet sample into plastic container after measuring the bulk density and pH value of the original sample, and number it and fill in the delivery form, and send it to the central laboratory. The storage time of the sample should not exceed half a month.
Article 5·2·4 The test method of rheological properties can be implemented according to the provisions of the appendix of this specification. When collating the data, the data under the flow channel should be excluded, and the measured verification number of 2000 should be used as the judgment value.
Article 5·2·5
The rheological properties test data can be stopped after meeting the requirements.
Section 3 Debris Flow. Observation of the Bottom of the Slurry River and the Riverbed Article 5.3.1 In areas with debris flow activities, when debris flow occurs in the test river section of the measuring station, observations shall be made in a timely manner according to the following requirements: 1. Observe the water level during the flood process; 2. Use a central buoy or source float to continuously measure the flow rate. Each time a buoy is measured, the water level shall be observed once and the observation time shall be recorded; 3. Use a horizontal sampler or a sampling trap to continuously sample the wells at the mainstream to record the sampling time. When it is difficult to take a semi-deep water sample at the mainstream, you can take a sample at the shore. When taking a sample, all the solid particles in the water sample shall not be removed; 4. For measuring stations with rheological properties test tasks, during the process of a large-scale debris flow, the debris flow slurry samples shall be taken 2 to 3 times, and the volume weight of the samples shall meet the test requirements.
Article 5.3-2 When mudslides occur near the measuring station, the situation should be reported to the monitoring agency in a timely manner, and investigations should be conducted as required according to the following requirements: 1. Investigate the precipitation process or precipitation in the period before the mudslide occurred. If there are difficulties, the total amount of precipitation and its duration should be investigated;
2. Investigate the geological and geomorphological conditions such as the flow area, ditch length, slope of hillside and ditch, soil quality, vegetation and riverbed age, slide or dry area, etc., estimate the amount of solid matter and record and photograph the actual scene in detail; 3. Take representative samples of debris flow deposits at different sections: take samples after mixing with the original sample, and send them to the central laboratory for determination and analysis of the total sand volume, particle size and other related items;
9-12
, estimate the characteristic values of the debris flow such as flow rate and total amount, and finally organize the investigation records. Preparation of investigation and photographic report
Article 5·3·3
When the "slurry river" phenomenon occurs in the test river section, observations should be carried out in a timely manner according to the following requirements:
1. Observe the entire process from flow to stagnation and then flow again:
2. Record the start time of each stagnation and flow. The corresponding water level, water surface gradient and water temperature:
3. Use a horizontal sampler to measure samples at the water surface, half depth and river bottom on the vertical line of the mainstream, and determine the sand content, particle grading and rheological properties respectively: When the slurry flows, the water depth and flow velocity should be measured, and the mud flow rate of the section should be calculated:
Record the actual process. Article 5·3·4 When the "slurry river bottom" phenomenon occurs in the test river section, observations should be carried out in a timely manner according to the following requirements:
Record the start time of the occurrence. Measure the location and river width of the occurrence, measure the volume of the riverbed objects exposed to the water surface, the speed of downstream advancement, the duration of continuation and the distance:
2. Measure the water depth and flow velocity, and add the water level, water surface gradient, single sample and bed sand; 3: Increase the number of flow wall and particle analysis measurements, and add water temperature measurement; 4. Describe the on-site situation in detail and take photos of the whole process. Article 5.3.5 Special phenomena such as mud flow, "slurry river" and "hot bottom" are characterized by suddenness and short-term nature, and full preparations must be made at ordinary times. For stations with more occurrences, on-site video or continuous imaging equipment should be planned.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.