Stability Evaluation Method of Horizontal Displacement Monitoring Control Network

Abstract

The invention relates to the field of stability evaluation of a horizontal displacement monitoring and control network, and provides a method for evaluating the stability of a horizontal displacement monitoring and control network based on a known system, comprising the following steps: collecting relevant data of the horizontal displacement monitoring and control network; establishing a scale benchmark, a direction benchmark and a position benchmark of the horizontal displacement monitoring and control network, that is, establishing a first-phase known system result (first-phase result), wherein the first-phase result of the first-phase horizontal displacement monitoring and control network includes the results of all horizontal displacement monitoring and control network points; taking the first-phase result as a benchmark, using the re-measured free network results of the horizontal displacement monitoring and control network of the analysis stable point, obtaining the parameters of a two-dimensional four-parameter plane coordinate conversion model, reducing the re-measured free network results to the known system results, obtaining the re-measured results and the weight of the re-measured results according to the value provisions of the re-measured results of the control network analysis method based on the known system, and calculating the displacement of the displacement point.

Description

Technical Field

[0001] The invention relates to the field of stability evaluation of a horizontal displacement monitoring control network, and in particular to a method for evaluating the stability of a horizontal displacement monitoring control network. Background Art

[0002] At present, the stability evaluation of the horizontal displacement monitoring and control network often focuses on the use of inherent instruments to measure the various parameters of the horizontal displacement monitoring and control network. However, due to the errors in instrument calibration and measurement data themselves, and the fact that the starting point of the horizontal displacement monitoring and control network may change during each measurement period, the displacement of the starting point may cause a systematic error, resulting in an inaccurate stability evaluation of the horizontal displacement monitoring and control, which is not conducive to the management of engineering safety monitoring work.

[0003] See patent application No. 201310195414.X, which discloses a displacement monitoring method for determining dam stability, including the following steps: (1) determining the overall range of the dam body and the detection network; (2) setting the dam displacement benchmark monitoring point; (3) installing monitoring equipment and acquiring data; (4) determining the dam trend displacement statistic r; (5) determining the critical statistic criterion rd for the dam overall trend displacement; (6) analyzing and determining the dam overall trend displacement r; (7) calculating and determining the dam overall trend displacement rate k; (8) evaluating the overall stability of the dam and warning of instability risk. The method of this patent application can provide graded warnings for dam instability and provide a basis for dam protection and management.

[0004] Then, the above patent application did not focus on the stability evaluation of the starting point of the horizontal displacement monitoring and control network, resulting in systematic errors in the calculations at each stage. Summary of the invention

[0005] The purpose of the present invention is to provide a method for evaluating the stability of a horizontal displacement monitoring and control network, which can effectively weaken the system error caused by the displacement of the starting point of the horizontal displacement monitoring and control network, measurement error and measurement instrument calibration error, improve the accuracy of the stability evaluation of the horizontal displacement monitoring and control network, provide a reliable working benchmark for engineering horizontal displacement monitoring work, and further improve the management level of safety monitoring work.

[0006] The present invention solves the technical problem and adopts the following technical solution:

[0007] The method for judging the stability of the horizontal displacement monitoring control network includes the following steps:

[0008] Step 1: Collect relevant information on the horizontal displacement monitoring and control network

[0009] Step 2: Calculation of first-period results;

[0010] Step 2.1 The first measurement of the horizontal displacement monitoring and control network is carried out in the first phase. The scale, direction and position benchmark of the horizontal displacement monitoring and control network are established according to the single-point single-direction free network adjustment, that is, the known system results (the first phase first results);

[0011] Step 2.2: Using the two-dimensional four-parameter conversion model, taking the first free net result of the first period as the benchmark, calculate the parameters of the two-dimensional four-parameter plane coordinate conversion model between the second free net result of the first period and the first free net result. According to this model, the second free net result of the first period is converted into the known system result, and the difference between the converted result and the first result of the first period is compared;

[0012] Step 2.3 Eliminate the points where the difference is greater than the stability judgment limit, recalculate the conversion model parameters, use the new conversion model to convert the free network results of the first period and the second measurement into the new known system results, and calculate the difference between the converted results and the first period and the first result again;

[0013] Step 2.4 Repeat steps 2.2-2.3 until all points with differences greater than the stability judgment limit are eliminated, and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated. The first-phase second-phase results are converted into known system results using the final two-dimensional four-parameter plane coordinate transformation model;

[0014] Step 2.5: Provisions for the first phase of results:

[0015] (1) Stable point

[0016] a) First period results = (first period first result + first period second calculation result) / 2;

[0017] b) The first period achievement rights = 1+1=2.

[0018] (2) Displacement point

[0019] a) First period results = first period second imputed results;

[0020] b) First-period achievement rights = 1;

[0021] Step 3: Calculate the results of the retest in this period;

[0022] Step 3.1 Perform free network adjustment on the re-measured observation values ​​of this period according to single point and single direction to obtain the free network results of the re-measured free network of the horizontal displacement monitoring and control network;

[0023] Step 3.2: Based on the previous period results, calculate the parameters of the two-dimensional plane coordinate transformation model between the current period retest free network results and the previous period results, convert the current period retest free network results into known system results according to this model, and compare the difference between the converted results and the previous period results;

[0024] Step 3.3 Eliminate the points whose difference is greater than the stability judgment limit, recalculate the conversion model parameters, use the new conversion model to convert the free network results of this period's retest into new known system results, and recalculate the difference between the converted results and the previous results;

[0025] Step 3.4 Repeat steps 3.2-3.3 until all points with differences greater than the stability judgment limit are eliminated, and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated. The final transformation model is used to convert the free network results of this period of retest into known system results;

[0026] Step 3.5 Regulations for the value of this period's results:

[0027] (1) Stable point

[0028] a) Current period results = (previous period results × previous period results rights + current period results) / (previous period results rights + 1);

[0029] b) The current period’s achievement rights = the previous period’s achievement rights + 1.

[0030] (2) Displacement point

[0031] a) Current period results = current period imputed results;

[0032] b) The current period's achievement rights = 1;

[0033] (3) Displacement amount and direction

[0034] a) Displacement during the period = previous period results - current period results; the displacement direction is represented by the azimuth of the displacement vector;

[0035] b) Cumulative displacement = first period results - current period results; the displacement direction is expressed by the azimuth of the displacement vector.

[0036] Furthermore, in step 1, the collected horizontal displacement monitoring control network data include but are not limited to monitoring design documents, original observation data, instrument calibration certificates, monitoring calculation data and monitoring reports.

[0037] Furthermore, step 2 is specifically as follows: taking the free network results of the first fixed single point and fixed single direction adjustment of the first observation of the horizontal displacement monitoring and control network in the first phase as the known system results, according to the two-dimensional four-parameter plane coordinate transformation model, the free network results of the second fixed single point and fixed single direction adjustment in the first phase are converted into known system results based on the adjustment results of the first fixed single point and fixed single direction in the first phase, and determining whether there are displacement points.

[0038] Furthermore, in step 2:

[0039] a) Taking the free network results of two fixed single-point and fixed single-direction adjustments as known data, the parameters of the two-dimensional four-parameter plane coordinate transformation model are obtained by removing the displacement points, which does not contain the displacement points;

[0040] b) Using the two-dimensional four-parameter plane coordinate transformation model calculated in a) to convert the free network results of the first and second fixed single-point and fixed single-direction adjustments into known system results;

[0041] c) The values ​​of the first known system results.

[0042] Furthermore, step c includes the following steps:

[0043] (a) The stable point takes the average of the first result and the second known system result as the first period result, and the result weight is 2;

[0044] (b) The displacement point is the first-phase result of the free network results of the second fixed single point and fixed single direction adjustment, with the result weight of 1. The displacement point refers to the point where the difference between the first-phase second free network known system reduction result and the first result is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network.

[0045] Furthermore, in step 3, after obtaining the resurvey results, the resurvey data is first preprocessed, and the preprocessing refers to obtaining the resurvey free network results by using a fixed single point and fixed single direction adjustment method.

[0046] Furthermore, after preprocessing the remeasured data, taking the previous results as the benchmark, the free network results of this remeasurement and the previous results as known data, the parameters of the two-dimensional four-parameter plane coordinate transformation model are calculated using the stable point results after eliminating the displacement points. This transformation model is used to convert the free network results of this period into known system results, and the values ​​of this period's results are taken.

[0047] Furthermore, the step of obtaining the value of the current period's results specifically includes the following steps:

[0048] (a) The stable point result is the weighted average of the previous period's result and the current period's result. The current period's result weight is the previous period's weight + 1.

[0049] (b) The displacement point results are taken as the results of the current period, and the weight of the results of the current period is 1, where the displacement points include: the point where the difference between the known system reduction results of the current period and the known system results of the previous period is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network, and the point where the difference between the known system reduction results of the current period and the known system results of the first period is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network.

[0050] Furthermore, it is characterized in that, in step 3.4, all displacement points are eliminated and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated, which specifically includes the following steps:

[0051] a) Taking the previous results and all the results of this period's free network results as known data, calculate the first two-dimensional four-parameter plane coordinate transformation model parameters;

[0052] b) Using the conversion parameters calculated in a) to convert the current period's free network results into the results based on the previous period's results, compare the known system results of the two periods, and determine the points with a difference greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network as displacement points;

[0053] c) After removing the displacement points, recalculate the model parameters of the second two-dimensional four-parameter plane coordinate transformation;

[0054] d) Repeat b) and c) until all displacement points are eliminated and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated.

[0055] Furthermore, after the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated, the stability analysis conclusion of the horizontal displacement monitoring control network can be obtained according to the provisions of step 2.5 and step 3.5 of claim 1.

[0056] The beneficial effect of the present invention is that through the above-mentioned horizontal displacement monitoring control network stability evaluation method, the system error caused by translation, scaling, rotation, etc. of the observation data can be weakened, the stability of the control network points can be accurately evaluated, and a reliable observation work benchmark can be provided for engineering horizontal displacement monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a flow chart of a method for judging the stability of a dam horizontal displacement monitoring and control network during operation according to the present invention;

[0058] Figure 2 It is a layout diagram of the horizontal displacement control network and the verification network of Jinping I Hydropower Station in an embodiment of the present invention;

[0059] Figure 3 This is a diagram showing the layout of the network points for monitoring the surface deformation below the water level of the reservoir in front of the left bank of the Jinping I Hydropower Station in this embodiment;

[0060] Figure 4 This is a diagram showing the network layout of the base point for monitoring the surface deformation of the Jinping I Hydropower Station dam rear bridge and atomization area in this embodiment;

[0061] Figure 5 It is the horizontal displacement reference network and verification network of the Ertan Hydropower Station dam in this embodiment;

[0062] Figure 6 This is a network diagram of the virtual control network in this embodiment. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0064] The present invention proposes a method for evaluating the stability of a horizontal displacement monitoring control network, and its flow chart is shown in Figure 1 , wherein the method comprises the following steps:

[0065] S1. Collect data on the horizontal displacement monitoring and control network; the collected data include but are not limited to monitoring design documents, original observation data, instrument calibration certificates, monitoring calculation data, monitoring reports and other related information.

[0066] S2. Acquire the first phase results of the horizontal displacement monitoring and control network, establish the scale, direction and position benchmark of the horizontal displacement monitoring and control network, and form a known system result. The first phase horizontal displacement monitoring and control network includes all control points.

[0067] Here, the free network results of the first fixed single point and fixed single direction adjustment of the first observation of the horizontal displacement monitoring and control network are taken as the known system. According to the two-dimensional four-parameter plane coordinate transformation model, the free network results of the second fixed single point and fixed single direction adjustment of the first period are converted into the known system results based on the free network results of the first fixed single point and fixed single direction adjustment of the first period, and it is determined whether there is a displacement point.

[0068] Specifically, S2 includes the following steps:

[0069] a) Taking the free network results of two fixed single-point and fixed single-direction adjustments as known data, the parameters of the two-dimensional four-parameter plane coordinate transformation model are obtained by removing the displacement points, which does not contain the displacement points;

[0070] b) Using the two-dimensional four-parameter plane coordinate transformation model calculated in a) to convert the free network results of the first and second fixed single-point and fixed single-direction adjustments into known system results;

[0071] c) The value of the first phase results (known system results).

[0072] Wherein, step c includes the following steps:

[0073] (a) The stable point takes the average of the first result and the second known system result as the first period result, and the result weight is 2;

[0074] (b) The displacement point is the first-phase result of the free network results of the second fixed single point and fixed single direction adjustment, with the result weight of 1. The displacement point refers to the point where the difference between the first-phase second free network known system reduction result and the first result is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network.

[0075] S3. Re-measure the horizontal displacement monitoring and control network and obtain re-measurement results.

[0076] After obtaining the resurvey results, the resurvey data are first preprocessed, and the preprocessing refers to obtaining the resurvey free network results by using a fixed single point and fixed single direction adjustment method.

[0077] S4. Taking the previous period's results as the benchmark, using the current period's re-measured free network results and the previous period's results as known data, the stable point results after eliminating the displacement points are used to calculate the parameters of the two-dimensional four-parameter plane coordinate transformation model. The transformation model is used to convert the current period's free network results into known system results, and the current period's results are valued.

[0078] The step of obtaining the value of the current period's results specifically includes the following steps:

[0079] (a) The stable point result is the weighted average of the previous period's result and the current period's result. The weight of the current period's result is the weight of the previous period's result + 1;

[0080] (b) The displacement point results are taken as the results of the current period, and the weight of the results of the current period is 1, where the displacement points include: the point where the difference between the known system reduction results of the current period and the known system results of the previous period is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network, and the point where the difference between the known system reduction results of the current period and the known system results of the first period is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network.

[0081] S5. Compare the current results with the previous results to determine the displacement amount and direction of the stable points and displacement points.

[0082] Here, all displacement points are eliminated and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated, which specifically includes the following steps:

[0083] a) Taking the previous results and all the results of this period's free network results as known data, calculate the first two-dimensional four-parameter plane coordinate transformation model parameters;

[0084] b) Using the conversion parameters calculated in a) to convert the current period's free network results into the results based on the previous period's results, compare the known system results of the two periods, and determine the points with a difference greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network as displacement points;

[0085] c) After removing the displacement points, recalculate the model parameters of the second two-dimensional four-parameter plane coordinate transformation;

[0086] d) Repeat b) and c) until all displacement points are eliminated and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated.

[0087] After the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated, the stability of the horizontal displacement monitoring control network is verified.

[0088] Example

[0089] This embodiment is described in detail by taking Jinping I Hydropower Station and Ertan Hydropower Station as examples.

[0090] In this embodiment, the engineering hub areas of Jinping I Hydropower Station and Ertan Hydropower Station are both located in high mountain canyon areas, with dedicated high-grade roads passing through, and relatively convenient transportation. The climate is relatively humid only in the rainy season throughout the year, and it is very dry at other times. The temperature varies greatly between day and night, and the sunshine is abundant. The meteorological conditions for external deformation observation are not ideal.

[0091] 1. Jinping I Hydropower Station

[0092] Jinping I Hydropower Station is located in Yanyuan County and Muli County of Liangshan Yi Autonomous Prefecture, Sichuan Province. It is a "controlling" reservoir cascade in the hydropower development plan of the middle and lower reaches of the Yalong River. The project is huge in scale. The development task is mainly to generate electricity. Combined with water storage during the flood season, it also plays a role in flood control in the middle and lower reaches of the Yangtze River. The installed capacity of the power station is 3,600MW. The dam is the world's highest arch dam, with a height of 305m. The normal water level of the reservoir is 1,880.00m, the dead water level is 1,800.00m, and the storage capacity below the normal water level is 7.76 billion m 3 , regulating reservoir capacity 4.91 billion m 3 , which is an annual regulation reservoir. The hub is mainly composed of permanent buildings such as a concrete hyperbolic arch dam, 4 surface holes + 5 deep holes + 2 emptying bottom holes on the dam body, a water cushion pond behind the dam, a pressure-connected non-pressure spillway on the right bank, and an underground powerhouse in the middle of the right bank. The power station is located in a deep mountain valley area with complex geological conditions, huge engineering scale, and high technical difficulty, especially the maximum height of the dam is 305m. Its technical level is at the forefront of the world. Figure 2-4 , the layout of the plane monitoring and control network is as follows:

[0093] (1) Hub area horizontal displacement control network and verification network

[0094] According to the scale of Jinping I Hydropower Station and the topographic and geological conditions of the dam area, a total of 10 points were selected on both sides of the Yalong River near the dam area, including 4 calibration base points (TM1~TM4) and 6 monitoring base points (TN1~TN6), forming a plane monitoring control network (such as Figure 1 As shown in Figure 1.5, the double geodetic quadrilateral synthetic calibration network is composed of six points, namely, calibration base points TM1, TM2, TM3, TM4 and TN1, TN2. TM1 and TM2 are used as the benchmarks of the calibration network. The stability of TN1 to TN4 is calibrated by geodetic method. At the same time, an inverted plumb line is laid at TN1, TN2, TN3, and TN4, and the inverted plumb lines are numbered IP1 to IP4. The monitoring results of the horizontal displacement of the inverted plumb line are mutually verified with the measurement results of the calibration network.

[0095] The horizontal displacement control network and verification network of Jinping Level 1 hub area were observed in accordance with the technical requirements of first-order side angle measurement. The first phase of observation was carried out in November 2010, and then re-measured once a year. The observation was intensified after the dam was filled with water.

[0096] (2) Surface deformation monitoring work base point network below the reservoir water level in front of the left bank dam

[0097] According to the actual situation on site, the horizontal displacement monitoring of the measuring area below the reservoir water level on the left bank slope dam is affected by the line of sight, and independent working base points TNG-1 and TNG-2 are used for observation and calculation. The annual working base point calibration is carried out after the observation of the horizontal displacement control network in the hub area. The calibration of the working base points TNG-1 and TNG-2 uses the points TN5 and TN3 of the horizontal displacement control network in the hub area of ​​Jinping I Hydropower Station as the observation and calculation basis.

[0098] The surface deformation monitoring work base point network below the reservoir water level in front of the left bank dam was observed in accordance with the technical requirements of first-order angle measurement. The first observation was carried out in October 2016, and then repeated once a year.

[0099] (3) Surface deformation monitoring work base network of the dam rear bridge and atomization area

[0100] According to the actual situation on site, the surface deformation of the bridge behind the dam and the fogging area on the left and right banks was observed. The surface deformation monitoring of the survey area affected by the visibility conditions was carried out by networking the working base points TNWH1, TNWH2, TNWH3, TNWH4 with the control network points TN4, TN2, TN1 for joint measurement, and the classic free network adjustment was carried out with three-point constraints.

[0101] The base point network for monitoring the surface deformation of the dam's rear bridge and atomization area was observed in accordance with the technical requirements of first-order angle measurement. The first phase of observation was carried out in April 2013, and repeated observations were carried out once a year thereafter.

[0102] 2. Ertan Hydropower Station

[0103] Ertan Hydropower Station is located on the main stream of Yalong River in Panzhihua City, Sichuan Province. It is the first power station in the cascade development of Yalong River. The normal water level of the reservoir is 1200m, and the total storage capacity is 5.8 billion m 3 , regulating reservoir capacity 3.37 billion m 3 The reservoir has seasonal regulation capabilities. The total installed capacity of the power station is 3,300MW (six 550MW Francis turbine generator sets). The Ertan Hydropower Station Dam is a concrete parabolic hyperbolic arch dam built on syenite and basalt. The maximum dam height is 240m and the dam top arc length is 774.69m. It is the first 200m high arch dam built in my country. Figure 5 , the layout of the plane monitoring and control network is as follows:

[0104] The horizontal displacement monitoring and control network of the Ertan Hydropower Station dam is composed of a plane reference network and a plane verification network. The plane verification network is composed of points C0 to C4, and the plane reference network is composed of points C5 to C12 and the original temporary plane monitoring points III06 and III11. The whole network has 15 points. The horizontal displacement reference network completed its first observation between February and April 2000, and was re-measured at a frequency of once a year.

[0105] The horizontal displacement control network and verification network of Jinping I Hydropower Station hub area, the surface deformation monitoring base point network below the water level of the reservoir in front of the left bank dam, and the surface deformation monitoring base point network of the bridge behind the dam and the atomization area are all first-order equal-angle networks.

[0106] The plane reference network and plane verification network for monitoring the horizontal displacement of the Ertan Hydropower Station dam are both first-order equal-angle networks.

[0107] Relevant literature can be consulted to investigate the current status of the industry's dam deformation monitoring and control network stability assessment technology and related research results. Through literature research, investigation and research, data analysis and comparative research methods, the monitoring data of the horizontal displacement monitoring and control network of this project over the years can be comprehensively sorted out to analyze and identify the weak links in the stability analysis of the original data.

[0108] In specific applications, the following procedures can be followed:

[0109] 1) Data collection

[0110] The data collection should include: monitoring design documents, original observation data, instrument calibration certificates, monitoring calculation data, monitoring reports and other relevant information.

[0111] 2) The first phase of monitoring and control network adjustment is to establish a known system.

[0112] 3) Free network adjustment of the monitoring and control network in other periods.

[0113] The observation data of each period are adjusted according to the free network to obtain the free network results of each period, evaluate the quality of the observation data of each period, and check the conformity of the quality of the results of each period with the design documents.

[0114] 4) For the remaining periods, the monitoring and control network and free network results are known, and the system reduction model solution and results calculation are carried out.

[0115] 5) Calculation of the deviation of stable points and displacement of displacement points of the monitoring control network for other periods.

[0116] Calculate the period difference between each period's results and the previous period's results and the cumulative difference between each period's results and the first period's results. The difference at the stable point is caused by the measurement error, while the difference at the displacement point is caused by the combined influence of the displacement and the measurement error.

[0117] 6) Analysis conclusions of the monitoring and control network for other periods.

[0118] 7) Compare and analyze the conclusions of the inverted observation with those of the known system analysis.

[0119] Compare the conclusions of the inverted observation with those of the known system analysis. When there are differences in the conclusions, on-site verification and analysis should be carried out.

[0120] 8) Form a final conclusion

[0121] Based on the analysis in 7), the final monitoring conclusion is formed.

[0122] 9) Standardized development of known system analysis software and preparation of analysis reports.

[0123] The known system analysis software currently in use is encapsulated into an execution file program for easy later use, and the analysis data of each period of monitoring and control network is bound into a book to form an analysis report.

[0124] When implementing this embodiment, the following problems are encountered:

[0125] 1) Eliminate or reduce system errors

[0126] Since the horizontal displacement deformation monitoring of the monitored body is carried out at the horizontal displacement monitoring reference point or the horizontal displacement monitoring working reference point, the stability analysis of the periodic re-measurement of the horizontal displacement monitoring control network must be an important task of horizontal displacement monitoring. However, the re-measurement of the horizontal displacement monitoring control network (including the calibration network, the reference network and the working reference point network) is affected by various factors such as personnel, equipment, environment, and methods, which makes it inevitable that there will be accidental errors and systematic errors between the re-measurement results and the previous results. Usually, the stability analysis is based on the accidental errors. Therefore, how to eliminate or weaken the systematic errors becomes the difficulty of the stability analysis of the horizontal displacement monitoring control network.

[0127] 2) Setting of stability point determination limit

[0128] Due to the inconsistency of control network structure and accuracy level, the accuracy of control network points is also inconsistent. Therefore, in order to obtain correct and reliable stability analysis conclusions, the first task is to determine the stable point displacement judgment limit. Therefore, setting the stable point judgment limit is also a difficult point.

[0129] To accurately find a way to eliminate or weaken the system error, we must first analyze the specific reasons for the system error. The horizontal displacement monitoring and control network of Jinping I Hydropower Station and Ertan Hydropower Station are both composed of first-order triangle networks. The observation elements of the triangle network include edges, angles, and meteorological elements. The Russian instruments used are high-precision total stations with a nominal angle measurement accuracy of 0.5″ and a distance measurement accuracy better than 1mm+1ppm. Plateau empty box barometers and exhaust-type dry and wet thermometers are usually used for adjustment. The method of fixed starting data is usually used.

[0130] 1. System error analysis

[0131] (1) Error analysis of side length observation system

[0132] a) Instrument calibration error

[0133] The specification stipulates that the instruments and equipment used for monitoring should be qualified by the metrology verification unit and should be used within the validity period of the qualification. However, due to the errors in the verification field used by the metrology verification unit, there will inevitably be errors in the addition constant and multiplication constant of the distance measurement side. If the verification constant containing errors is used to correct the side length, even if other conditions are the same, there will be systematic errors between the side lengths of different periods.

[0134] b) Errors caused by changes in environmental conditions

[0135] Changes in environmental conditions will also affect the measurement accuracy of instruments and equipment. Since the environmental conditions during measurements at different times cannot be completely consistent, the measurement data at different times will also produce systematic errors. This type of error includes the following two types.

[0136] (c) Meteorological element measurement errors;

[0137] (d) Total station side length measurement error.

[0138] Errors caused by instrument calibration errors and changes in environmental conditions will cause scaling errors in the results.

[0139] 2. Direction observation system error analysis

[0140] Taking the starting direction as an example, due to measurement errors, the observed values ​​of the starting direction between two phases of measurement cannot be completely consistent. Therefore, when other conditions are completely consistent, there will be a direction error between the two phases of results, that is, the results contain rotation errors.

[0141] 3. Fixed starting point system error analysis

[0142] a) Fixed starting point displacement

[0143] Any change in the position of the starting point used for adjustment will cause translation and rotation between the two phases of results, thus generating systematic errors.

[0144] b) Systematic errors not eliminated by adjustment methods

[0145] (a) The original data is adjusted in a hierarchical manner: namely, the calibration network, the datum network and the working base point network. The stability analysis is conducted based on the hierarchical adjustment results. When the difference between the two intervals of the fixed points used for the initial calculation does not exceed the deformation judgment value, it is judged to be stable. The fixed points used for the initial calculation in the subsequent adjustment use the previous values, but the initial calculation points have actually been deformed, but have not exceeded the deformation judgment value. Therefore, there must be systematic errors between the later and previous results.

[0146] (b) The deformation of the fixed starting point does not reach the deformation judgment value, but due to the combined influence of accidental errors and systematic errors, the difference between the two periods of adjustment results is greater than the deformation judgment value. The deformation of the fixed starting point is determined and the new results are used for adjustment, which will inevitably lead to a systematic error between the new results and the previous results.

[0147] Fixed starting point displacement and systematic errors that are not eliminated by the adjustment method will cause translation errors and rotation errors in the results.

[0148] Since there may be scale scaling, direction rotation and position translation between the re-survey of the horizontal displacement monitoring control network and the previous results, according to the "Technical Specifications for Coordinate Transformation of Geodetic Control Points" CH 2014-2016, the two-dimensional four-parameter plane coordinate transformation model can greatly eliminate or weaken the system errors of scaling, rotation and displacement between the two-phase results through coordinate transformation. Therefore, the results of the two-phase observation stable points can be used to calculate the parameters of the two-dimensional plane coordinate transformation model from the later results to the previous results. Through the transformation model, the later free network results are converted to the results with the previous results as the known system (scale benchmark, direction benchmark and position benchmark), thereby obtaining the results of the unified benchmark (known system).

[0149] After eliminating or weakening the systematic error, the result error is mainly accidental error, supplemented by systematic error. Therefore, the limit of the accidental error of the difference between the observation results of the same precision in two periods should be Taking into account the influence of residual system error, 3m is taken as the limit of stable point determination, m is the point position error of horizontal displacement monitoring control network, and its value is calculated by the following formula:

[0150]

[0151] in:

[0152] a-total station additive constant error, unit: mm;

[0153] b-total station multiplication constant error, unit: mm / km;

[0154] D-average side length of horizontal displacement monitoring and control network, unit: km;

[0155] m α- Horizontal displacement monitoring control network horizontal observation error, unit ";

[0156] ρ - is the constant of radians per second, 206265;

[0157] n 1 -Average number of observed edges of horizontal displacement monitoring control points;

[0158] n 2 -Average number of observation directions of horizontal displacement monitoring control points.

[0159] It should be noted that the specific operation method of this embodiment is:

[0160] (1) Establish the scale, direction and position benchmark of the horizontal displacement monitoring control network (known system)

[0161] The adjustment results of the fixed single point and fixed single direction of the first observation of the horizontal displacement monitoring control network (calibration network, benchmark network and working base point network) (referred to as free network results) are used as the known system. According to the two-dimensional four-parameter plane coordinate conversion model, the first-period second free network results are converted into known system results based on the first-period first free network results as the benchmark (scale, direction and position), and it is determined whether there is a displacement point. The specific implementation method is:

[0162] a) Take the results of the two free nets as known data and use the results of eliminating displacement points to find the parameters of the two-dimensional four-parameter plane coordinate transformation model; normally there should be no displacement points;

[0163] b) Using the conversion model calculated in a) to convert the first phase second free network results into known system results;

[0164] c) Value of the first phase results (known system results)

[0165] (a) The stable point takes the average of the first result and the second known system result as the first period result, and the result weight is 2;

[0166] (b) The displacement point takes the result of the known system reduction of the first period and the second period free network as the first period known system result, and the result weight is 1. The displacement point refers to the control network point where the difference between the first period and the second period free network known system reduction result and the first result is greater than 3m.

[0167] (2) Retest data preprocessing and stability analysis

[0168] a) Retest data preprocessing

[0169] The re-survey data pre-processing also uses the fixed single point and fixed single direction adjustment method to obtain the re-survey free network results;

[0170] b) Taking the known system results of the previous period as the benchmark, using the free network results of this period and the known system results of the previous period as known data, the stable point results after removing the displacement points are used to calculate the parameters of the two-dimensional four-parameter plane coordinate transformation model, and the free network results of this period are converted into known system results using this transformation model;

[0171] c) Value of this period's results (known system results)

[0172] (a) The stable point result is the weighted average of the known system result of the previous period and the calculated result of the current period. The result weight of the current period is the weight of the previous option + 1;

[0173] (b) The displacement point result is the result of the current period, and the result weight of the current period is 1.

[0174] The displacement points include: control points where the difference between the current period's known system calculation results and the previous period's known system results is greater than 3m, and control points where the difference between the current period's known system calculation results and the first period's known system results is greater than 3m.

[0175] (3) Calculation method of two-dimensional plane coordinate transformation model

[0176] a) Taking the previous period's results and the current period's free network results as all known data, calculate the first conversion model parameters;

[0177] b) Using the conversion parameters calculated in (1) to convert the current free network results to the results based on the previous known system results, compare the two known system results, and determine the points with a difference greater than 3m as displacement points;

[0178] c) After removing the displacement points, recalculate the second conversion model parameters;

[0179] d) Repeat b) and c) until all displacement points are eliminated and the final two-dimensional coordinate transformation model parameters are calculated.

[0180] Then, the theoretical data of the reliability of the known system analysis method in this implementation is verified. In actual application, the retest of the safety monitoring and control network usually encounters the following three problems:

[0181] 1) Changes in length standards caused by meteorological element observation errors, instrument replacement or regular instrument calibration;

[0182] 2) Direction change caused by observation error of the starting direction or displacement of the starting direction point;

[0183] 3) Displacement of the starting point in the starting direction;

[0184] 4) Observation fluctuation error caused by grid structure

[0185] The above reasons combined to cause the following problems:

[0186] 1) Changes in the length benchmark will have a scaling effect on the results;

[0187] 2) The observation error of the starting direction or the direction change caused by the displacement of the starting direction point will have a rotational effect on the results;

[0188] 3) The displacement of the starting point in the starting direction will have a translational effect on the results;

[0189] 4) The observation fluctuation error caused by the grid structure will produce accidental fluctuation error in the results.

[0190] Based on this, see Figure 6 , set up a virtual control network, which consists of 8 points, with the shortest side of 510.868m, the longest side of 1577.611m, the average side length of 1000.850m, 40 observation directions, 20 opposite sides, the prior angle measurement error of 0.7″, and the side measurement accuracy of 1mm+1mm / km.

[0191] The stability judgment displacement limit ΔP is:

[0192]

[0193] in:

[0194] D is the average side length in kilometers;

[0195] m α is the direction error, in seconds;

[0196] n 1 To control the average number of sides of the network points;

[0197] n 2 To control the average direction number of dots.

[0198] After calculation, the stability determination displacement limit in this example is 3.2mm.

[0199] The results of the virtual control network include the average results of the first two phases, the results of 10ppm magnification, the results of 1″ rotation, the results of 0.015m translation and the results of 0.015m translation and 1″ magnification of 10ppm. The results are shown in Tables 1 and 2.

[0200] Table 1 Results of the first phase of the virtual control network and the amplification of 10ppm

[0201]

[0202] Table 2 Results of virtual control network rotation 1″, translation 0.015m and translation 0.015m rotation 1′ amplification 10ppm

[0203]

[0204] The 10ppm magnification results, 1 second rotation results, 0.015m translation results and 0.015m translation and 1' rotation magnification 10ppm results in the case results are directly compared with the first-phase results. The comparison results are shown in Table 3.

[0205] Table 3 Comparison of the first phase results of the virtual control network with the results of amplification 10ppm and rotation 1 second results Unit: mm

[0206]

[0207] According to the data in 3, according to the given limit of 3.2mm for the displacement of stable points, it can be seen that: in the result of 10ppm amplification, only the starting point TN01 is stable, and the rest are displacement points; in the result of 1 second rotation, only the starting point TN01 and TN02 and TN03 which are closer to the starting point are stable, and the rest are displacement points; all the results of 0.015m translation and 0.015m translation and 1' rotation amplification by 10ppm are displacement points.

[0208] Finally, the known system analysis conversion results are compared with the first phase conclusions:

[0209] Convert the amplified 10ppm result in the case results into the following formula:

[0210] X=(0.999990024796369).x+(-5.4057252887891E-09).y+(32.12114555794)

[0211] Y=(5.4057252887891E-09).x+(0.999990024796369).y+(5.030165890173)

[0212] Convert the 1″ rotation result in the case result into the following formula:

[0213] X=(1.00000000123721).x+(4.85611480017656E-06).y+(-2.46124722241)

[0214] Y=(-4.85611480017656E-06).x+(1.00000000123721).y+(15.63522006321)

[0215] Convert the translation result of 0.015m in the case result into the following formula:

[0216] X=(1.00000000122123).x+(3.02191106073157E-08).y+(-0.00663590227)

[0217] Y=(-3.02191106073157E-08).x+(1.00000000122123).y+(0.104779957153)

[0218] The translation of 0.015m, rotation of 1' and amplification of 10ppm in the case results are converted as follows:

[0219] X=(0.999990003554322).x+(-4.84761178102376E-06).y+(34.66894471007)

[0220] Y=(4.84761178102376E-06).x+(0.999990003554322).y+(-10.5488242638)

[0221] The comparison between the conversion results and the first phase results is shown in 11.

[0222] Table 11 Comparison of the first phase results of the virtual control network with the results of amplification 10ppm and rotation 1 second results Unit: mm

[0223]

[0224] This shows that the known system analysis method can effectively eliminate the influence of system errors, and the conclusions of the analysis are consistent with the actual conclusions.

Claims

1. A method for evaluating the stability of a horizontal displacement monitoring control network, characterized in that: The steps include: Step 1: Collect relevant information of horizontal displacement monitoring and control network; Step 2: Calculation of first-period results; Step 2 is specifically as follows: taking the adjustment results of the fixed single point and fixed single direction of the first observation of the entire horizontal displacement monitoring and control network in the first period as the known system results, according to the two-dimensional four-parameter plane coordinate conversion model, the adjustment results of the second fixed single point and fixed single direction in the first period are converted into the known system results based on the adjustment results of the first fixed single point and fixed single direction in the first period, and determining whether there is a displacement point; Step 2.1 The first measurement of the horizontal displacement monitoring control network in the first phase, the scale, direction and position benchmark of the horizontal displacement monitoring control network are established according to the single-point single-direction free network adjustment, which is the first achievement of the first phase; Step 2.2: Using the two-dimensional four-parameter conversion model, taking the first free net result of the first period as the benchmark, calculate the parameters of the two-dimensional four-parameter plane coordinate conversion model between the second free net result of the first period and the first free net result. According to this model, the second free net result of the first period is converted into the known system result, and the difference between the converted result and the first result of the first period is compared; Step 2.3 Eliminate the points where the difference is greater than the stability judgment limit, recalculate the conversion model parameters, use the new conversion model to convert the free network results of the first period and the second measurement into the new known system results, and calculate the difference between the converted results and the first period and the first result again; Step 2.4 Repeat steps 2.2-2.3 until all points with differences greater than the stability judgment limit are eliminated, and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated. The first-phase second-phase results are converted into known system results using the final two-dimensional four-parameter plane coordinate transformation model; Step 2.5: Provisions for the first phase of results: (1) Stable point a) First period results = (first period first result + first period second calculation result) / 2; b) First-period achievement rights = 1+1=2; (2) Displacement point a) First period results = first period second imputed results; b) First-period achievement rights = 1; Step 3: Calculate the results of the retest in this period; Step 3.1 Perform free network adjustment on the re-measured observation values ​​of this period according to single point and single direction to obtain the free network results of the re-measured free network of the horizontal displacement monitoring and control network; Step 3.2: Based on the previous period results, calculate the parameters of the two-dimensional plane coordinate transformation model between the current period retest free network results and the previous period results, convert the current period retest free network results into known system results according to this model, and compare the difference between the converted results and the previous period results; Step 3.3 Eliminate the points whose difference is greater than the stability judgment limit, recalculate the conversion model parameters, use the new conversion model to convert the free network results of this period's retest into new known system results, and recalculate the difference between the converted results and the previous results; Step 3.4 Repeat steps 3.2-3.3 until all points with differences greater than the stability judgment limit are eliminated, and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated. The final transformation model is used to convert the free network results of this period of retest into known system results; Step 3.5 Regulations for the value of this period's results: (1) Stable point a) Current period results = (previous period results × previous period results rights + current period results) / (previous period results rights + 1); b) The current period's achievement rights = the previous period's achievement rights + 1; (2) Displacement point a) Current period results = current period imputed results; b) The current period's achievement rights = 1; (3) Displacement amount and direction a) Displacement during the period = previous period results - current period results; the displacement direction is represented by the azimuth of the displacement vector; b) Cumulative displacement = first period results - current period results; the displacement direction is expressed by the azimuth of the displacement vector.

2. The method for evaluating the stability of a horizontal displacement monitoring and control network according to claim 1 is characterized in that: In step 1, the collected data include monitoring design documents, original observation data, instrument calibration certificates, monitoring calculation data and monitoring reports.

3. The method for evaluating the stability of a horizontal displacement monitoring and control network according to claim 1 is characterized in that: In step 2: a) Taking the free network results of two fixed single-point and fixed single-direction adjustments as known data, the parameters of the two-dimensional four-parameter plane coordinate transformation model are obtained by removing the displacement points, which does not contain the displacement points; b) Using the two-dimensional four-parameter plane coordinate transformation model calculated in a), the free network results of the first and second fixed single-point and fixed single-direction adjustments are converted into known system results; c) The values ​​of the first known system results.

4. The method for evaluating the stability of a horizontal displacement monitoring and control network according to claim 3 is characterized in that: Step c) comprises the following steps: (a) The stable point takes the average of the first result and the second known system result as the first period result, and the result weight is 2; (b) The displacement point is the first-phase result of the free network results of the second fixed single point and fixed single direction adjustment, and the known system reduction result is taken as the first-phase result. The result weight is 1. The displacement point refers to the point where the difference between the first-phase second free network known system reduction result and the first result is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network.

5. The method for evaluating the stability of a horizontal displacement monitoring and control network according to claim 1 is characterized in that: In step 3, after obtaining the re-survey observation data, the re-survey data is first pre-processed, and the pre-processing refers to obtaining the re-survey free network results by using a fixed single point and fixed single direction adjustment method.

6. The method for evaluating the stability of a horizontal displacement monitoring and control network according to claim 5 is characterized in that: After preprocessing the remeasured data, the previous results are taken as the benchmark, the free network results of this period's remeasurement and the previous results are used as known data, and the stable point results after eliminating the displacement points are used to calculate the parameters of the two-dimensional four-parameter plane coordinate transformation model. This transformation model is used to convert the free network results of this period into known system results, and the values ​​of the known system results of this period are taken.

7. The method for evaluating the stability of a horizontal displacement monitoring and control network according to claim 6 is characterized in that: The step of obtaining the value of the known system achievements of this period specifically includes the following steps: (a) The stable point result is the weighted average of the previous period's result and the current period's result. The current period's result weight is the previous option + 1; (b) The displacement point results are taken as the results of the current period, and the weight of the results of the current period is 1, where the displacement points include: the point where the difference between the current period's known system reduction results and the previous period's results is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network, and the point where the difference between the current period's known system reduction results and the first period's known system results is greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network.

8. The method for evaluating the stability of a horizontal displacement monitoring and control network according to any one of claims 1 to 7, characterized in that: Step 2.4 and step 3.4, remove all displacement points and calculate the final two-dimensional four-parameter plane coordinate transformation model parameters, specifically including the following steps: a) Taking the previous results and all the results of this period's free network results as known data, calculate the first two-dimensional four-parameter plane coordinate transformation model parameters; b) Using the conversion parameters calculated in a) to convert the current free network results to the results based on the previous results, compare the converted results with the previous results, and determine the points with a difference greater than 3 times the error in the estimation of the horizontal displacement monitoring and control network as displacement points; c) After removing the displacement points, recalculate the model parameters of the second two-dimensional four-parameter plane coordinate transformation; d) Repeat b) and c) until all displacement points are eliminated and the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated.

9. The method for evaluating the stability of a horizontal displacement monitoring and control network according to claim 8, characterized in that: After the final two-dimensional four-parameter plane coordinate transformation model parameters are calculated, the stability analysis conclusion of the horizontal displacement monitoring control network can be obtained according to the provisions of step 2.5 and step 3.5 of claim 1.

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