CN102607646A - Riverbank stability monitoring, analysis and assessment method - Google Patents

Abstract

A method for monitoring, analyzing and evaluating river bank stability, including establishing a monitoring wire based on the topographic map of the near-shore river bed and a monitoring data collection network for the analysis section of the underwater slope of the near-shore river bed; The topographic map of the near-shore riverbed where the monitoring wire is located is digitized, and the topographic map of the near-shore riverbed of the river where the intersection of the underwater slope monitoring starting point and ending wire, the erosion-silting monitoring wire and the monitoring analysis section is digitized. Based on the obtained data and results, draw the relationship diagram of the riverbed elevation change along the process of the erosion-silting monitoring wire and draw the relationship diagram of the change relationship of the near-shore riverbed underwater slope and slope toe slope ratio along the process, and calculate the average value of each segment; according to the above The results and technical parameters such as the geological boundary conditions of the river bank are assigned to each section according to the detailed rules of the classification, grade, feature, and scoring rules, and then the comprehensive evaluation score is calculated, and the bank slope stability risk level of the corresponding section is evaluated.

Description

Analysis and Evaluation Method of Riverbank Stability Monitoring

technical field

The invention relates to the technical field of water conservancy engineering, in particular to a method for monitoring, analyzing and evaluating river bank stability.

Background technique

Bank collapse is a manifestation of river channel evolution, which is commonly found in alluvial plain channels. The impact of bank collapse is not only that the beach in relevant areas is gradually "eroded" and disappears, but more importantly, bank collapse endangers the embankment projects built on the beach. Basic security, which in turn threatens the safety of people's lives and property in the embankment protection area, affects the development and utilization of river shoreline resources, the normal use of water conservancy facilities on both sides of the river, and the normal development of the social economy in the embankment protection area. River revetment engineering is an effective measure to maintain or control the stability of the river bank. It is widely used in alluvial plain river improvement projects. Like all construction projects, river revetment engineering is not once and for all, and has its natural life, especially underwater revetment Engineering, water damage is the main factor affecting the natural life of river revetment works, and the bank slopes that lose the protection of revetment works are not far from the day when bank collapse occurs.

At present, the risk management of river bank stability is basically the treatment after bank collapse, and it is still difficult to prevent it from burning before it burns. The scale is much larger. The collapse of the river bank or the instability of the river bank is a process of continuous accumulation of river bank stability risks. It generally goes through the time process of the occurrence, cumulative development, and occurrence of bank stability risks. Prevention of unburned hazards, timely treatment of hidden dangers of river bank stability, has a significant effect on maintaining the stability of river banks, and can avoid major safety accidents such as flood control. Analyzing and evaluating the degree of river bank stability risk is an important basis for determining the treatment of river bank stability risk, and it has a guiding role in the flood control and rescue work of river courses.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for monitoring, analyzing and evaluating river bank stability, which can detect in time the degree and changing trend of bank stability risks of alluvial plain rivers, especially downstream rivers of reservoir dams, and directly identify banks with potential safety hazards. Provide technical guidance for risk management of relevant river sections; provide technical support for safety management such as flood control safety in embankment engineering protection areas of relevant river sections, and safe operation of water conservancy facilities on both sides of the river.

A method for monitoring, analyzing and evaluating river bank stability, comprising the following steps:

Step A: Establish a monitoring data collection network based on the topographic map of the near-shore river bed and the monitoring data collection section of the underwater slope analysis section of the near-shore river bed; there are 3 monitoring wires, namely, the erosion-silting monitoring wire, the underwater slope monitoring starting wire, and the water slope monitoring wire. The lead wire at the end point of slope monitoring; the underwater slope analysis section is arranged as required, and generally one monitoring and analysis section is arranged at an interval of 50-300m;

Step B: Based on the topographic map of the near-shore river bed of the river course, digitize the topographic map of the river bed near the bank where the erosion-silting monitoring wire is located, and draw the river bed of the erosion-silting monitoring wire along the flow direction according to the obtained data and results Elevation change relationship diagram, and calculate the average elevation change of each segment;

Step C: Based on the topographic map of the near-shore riverbed of the river course, digitize the topographic map of the location of the intersection of the monitoring wire and the monitoring and analysis section perpendicular to the flow direction of the river course, and draw according to the obtained data results. The relationship diagram of the slope ratio change along the process of the underwater slope and slope toe of the near-shore river bed, and calculate the average value of the slope ratio for each segment;

Step D: According to the above analysis results, combined with the geological boundary conditions of the river bank, the external force conditions of the river regime and runoff, the shoreline status and the analysis and evaluation of the river regime evolution elements of the river section where the bank section is located, according to the classification and grading rules of the risk factors affecting the bank stability, the Analyze and evaluate the bank section to classify and assign grades, and then calculate the comprehensive score value. Among them, the geological structure of the river bank slope and the revetment situation are the geological boundary conditions that affect the stability of the river bank; according to the interval of the bank slope stability risk level where the comprehensive score value is located , to determine the slope stability risk level of the corresponding section.

The present invention has following beneficial effects:

(1) It can comprehensively and directly reflect the changes of scouring and silting of the near-shore riverbed along the monitoring section, overcome the representative limitations of the typical section method in analyzing the changes of the near-shore riverbed, and directly discover the changes of scouring and silting of the near-shore riverbed along the monitoring section. (Following the flow direction) distribution relationship, with the characteristics of overall quantitative analysis;

(2) It can fully and directly reflect the changes of the underwater slope of the near-shore riverbed along the monitoring section and the inner slope at the foot of the slope, so as to directly discover the distribution relationship along the course (following the flow direction) of the variation of the underwater slope of the near-shore riverbed in the monitoring section. , has the characteristics of overall quantitative analysis.

(3) To objectively evaluate the stability of the river bank, predict the possibility of bank collapse, provide scientific basis for the prevention and treatment of bank collapse hazards, and provide technical support for river safety management.

Description of drawings

Figure 1 is the layout of the monitoring wires and monitoring sections of the near-shore riverbed in the North Gate section;

Figure 2 is a schematic diagram of the sub-division of the underwater slope and the inner slope at the toe of the near-shore riverbed monitoring section, taking the North Gate section of the Jingjiang section of the Yangtze River as an example;

Figure 3 is an example of the north gate area of the Jingjiang section of the Yangtze River, and the elevation change diagram of the monitoring wire at the front of the underwater slope toe of the near-shore riverbed;

Figure 4 takes the Beimenkou section of the Jingjiang section of the Yangtze River as an example, and the change of the slope ratio of the underwater slope of the near-shore riverbed along the course;

Figure 5 is an example of the variation of the inner slope ratio at the toe of the near-shore riverbed, taking the Beimenkou section of the Jingjiang section of the Yangtze River as an example.

Detailed ways

The technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention.

The bank stability monitoring analysis and evaluation method of the present invention comprises the following steps:

Step A: Establish monitoring wires based on topographic maps of near-shore riverbeds and monitoring data collection network for underwater slope analysis sections of near-shore riverbeds; Conductor at the end point of slope monitoring; underwater slope analysis sections are arranged as required, and generally one monitoring and analysis section is arranged at an interval of 50-300m.

When determining the plane coordinate position of the scouring and silting monitoring wire, comprehensively consider the following elements: 1. For those with underwater bank revetment works, the width of the underwater river bank revetment project should be considered, and the distance between the plane position of the scouring and silting monitoring wire The outer edge of the project is 5 to 30 meters; ② For the section of underwater bank revetment without river bank revetment, the plane position of the erosion-silting monitoring wire is determined according to the width of the inner edge line of the near-shore deep groove from the multi-year average low water level line, and the erosion-silting monitoring wire The plane position of the river is 60-150 meters away from the multi-year average dry water level; ③ At the same time, considering the irregularity of the river's dry water level and the smoothness of the main stream near the coast in the dry season, the plane position of the erosion and deposition monitoring wire is properly adjusted to make the erosion and sedimentation monitoring wire smooth .

Consider the following elements when determining the plane coordinate position of the underwater slope monitoring starting line: the riverbed elevation at the location of the control point on the line is 2 to 3m lower than the average dry water level for many years;

The following content elements are considered when determining the plane coordinate position of the underwater slope monitoring terminal wire: the position of the control point on the wire is near the "inflection point" of the section shape change near the foot of the slope;

Taking the Beimenkou section as an example (as shown in Figure 1), the total length of the monitoring shore section at Beimenkou is 6km, of which the section with pile number 6+000~9+000 (3km in length) is the revetment section, and the width of the underwater revetment project is 60m~80m ; Stake No. 9+000～12+000 (3km in length) is the section without revetment works. The scouring and silting monitoring wire is a smooth multi-point curve, which is located near the front of the underwater works in the revetment section of the river channel and near the inner edge line of the near-shore deep groove in the un-reverted section of the river channel. It is basically guaranteed to pass through the near-shore deep groove. The 25.6m (85 Yellow Sea base) line is about 80-120m, and the dry water level of 25.6m is the monthly water level from December to March of the next year from June 2003 (after the water storage of the Three Gorges Project) to December 2011. annual average. According to the content requirements of the above-mentioned arrangement of monitoring wires, determine the starting wire of underwater slope monitoring, the end wire of underwater slope monitoring, and the wire of erosion and silting monitoring in the North Gate section, see Figure 1 for details; the underwater slope analysis section is arranged at intervals of 1 monitoring analysis section , see Figure 1 for details.

Step B: Based on the topographic map of the near-shore river bed of the river course, digitize the topographic map of the river bed near the bank where the erosion-silting monitoring wire is located, and draw the river bed of the erosion-silting monitoring wire along the flow direction according to the obtained data and results Elevation change relationship diagram, and calculate the average elevation change of each segment;

Described step B specifically comprises:

Data collection: Take a set point on the monitoring wire (for example: the upstream top point of the monitoring wire) as the origin, corresponding to the pile number of the bank protection bank engineering, and collect an elevation value at a certain distance along the monitoring wire.

Data processing: Use EXCEL and AUTOCAD programs to draw the elevation change map of the monitoring wire (as shown in Figure 3); analyze the elevation change graph of the monitoring wire in different periods, and calculate the erosion or deposition of each section according to the characteristics of the elevation change of the monitoring wire Amplitude.

Step C: Based on the topographic map of the near-shore riverbed of the river course, digitize the topographic map of the location of the intersection of the monitoring wire and the monitoring and analysis section perpendicular to the flow direction of the river course, and draw according to the obtained data results. The relationship diagram of the change of the slope ratio of the underwater slope and the slope toe of the near-shore river bed along the process, and calculate the average value of the elevation change of each segment;

Described step C specifically comprises:

Data collection: The underwater slope ratio of the monitoring section is the segmental average generalization of the underwater bank slope of the river channel. The underwater bank slope is divided into the underwater slope and the inner slope at the foot of the underwater slope. Underwater slope range: the area between the underwater slope monitoring start wire and the underwater slope monitoring end wire; the underwater slope toe inner slope range: the area between the underwater slope monitoring end wire and the erosion and silting monitoring wire. The intersection of the monitoring section line and the underwater slope monitoring start wire and the underwater slope monitoring end wire is the original data collection point of the underwater slope slope ratio. The river bed elevation and horizontal distance at the intersection point are used to calculate the underwater slope slope ratio of the relevant monitoring section. The intersection of the monitoring section line and the underwater slope monitoring terminal wire and the erosion-silting monitoring wire is the original data collection point of the slope ratio at the foot of the underwater slope. Read the riverbed elevation and the horizontal distance between the two points at each collection point. 2 The river bed elevation and horizontal distance at the intersection point calculate the slope ratio of the underwater slope toe of the relevant monitoring section.

Data processing: Calculate the slope ratio of the underwater slope and the inner slope ratio of the underwater slope toe of each monitoring section, and use EXCEL and AUTOCAD programs to draw the variation map of the slope ratio of the underwater slope and the inner slope of the underwater slope toe ( See Figures 4 and 5 for details); analyze the slope ratio change diagrams along the course in different periods, and calculate and divide the underwater slope ratio and the variation range of the underwater slope toe slope ratio in sections according to the slope ratio change characteristics.

Step D: According to the above analysis results, combined with the geological boundary conditions of the river bank, the external force conditions of the river regime and runoff, the shoreline status and the analysis and evaluation of the river regime evolution elements of the river section where the bank section is located, according to the classification and grading rules of the risk factors affecting the bank stability, the Analyze and evaluate the bank section to classify and assign grades, and then calculate the comprehensive assessment value. Among them, the geological structure of the river bank slope and the bank revetment are the geological boundary conditions that affect the stability of the river bank; interval to determine the bank slope stability risk level of the corresponding section. The slope stability risk assessment is divided into 4 levels: general, second-level fortification, first-level fortification, and alert level. The corresponding color prompts are: green coast section, blue coast section, orange warning coast section, and red warning coast section. The river regime is the relative relationship between the mainstream line of the river channel and the river bank and the edge line of Jiangxinzhou (beach). The river regime evolution elements include: the variation range of the plane position of the mainstream line of the river channel, the plane position of the bank line and the edge line of the Jiangxinzhou (shoal) under the condition of the river channel flood control water level.

Detailed scoring rules for classification and grading of risk factors affecting river bank stability:

The detailed rules for classification and grade feature scoring items are divided into: conditional feature items, scour process feature items, and shoreline condition feature items. The scores for each type of item are as follows:

1. Conditional feature scoring terms

The conditions and characteristics scoring items are divided into geological boundary conditions and river regime runoff external force conditions. The geological structure of the river bank slope and revetment are geological boundary conditions that affect the stability of the river bank, and the river regime runoff characteristics are the external force conditions that affect the stability of the river bank. The weighted average method is adopted for the comprehensive score of the condition characteristic clause, among which, the geological boundary condition accounts for 70%, and the external force condition of river regime and runoff accounts for 30%; The score of the structure is 0-10, the score of the revetment is 0-7, and the score is the highest measurement principle; the score of the external force condition of the river regime and runoff is 0-3. The following is an example of the assignment of conditional feature clauses:

1) Grade clauses for slope geological structure conditions:

Ground-1: Binary structure with sand on the top and sand on the bottom, with a score of 0;

Ground-2: silt layer structure, assigned a score of 0;

Land-3: loamy soil mixed with sand layer structure, assigned a score of 1;

Land-4: loam structure, assigned a score of 2;

Land-5: old clay structure, with a score of 5;

Ground-6 rock structure, with a score of 10.

2) Condition grade clauses of revetment:

Protection-0: the section without revetment is assigned a score of 0;

Protection-1: The revetment project implemented before 1998 has not been reinforced after 1998, and the score is +2;

Protection-2: The bank revetment project implemented before 1998, underwater reinforcement from 1999 to 2003, water slope protection project transformation, is basically in good condition now, and the score is +3;

Protection-3: The bank revetment project implemented before 1998, the underwater reinforcement and above-water slope protection project transformation from 2006 to 2009, is basically in good condition now, and the score is +5;

Protection-4: The bank revetment project implemented before 1998, the underwater reinforcement and water slope protection project transformation from 2010 to 2011, is basically in good condition now, and the score is +4;

Protection-5: The new revetment project implemented from 1999 to 2003 has not been reinforced after 2003, and the slope protection project on the water is basically intact, and the score is +5;

Protection-6: The new bank revetment project implemented from 1999 to 2003 has not been reinforced after 2003, and there are many damages in the water slope protection project, and the score is +4;

Protection-7: New revetment projects or reinforcement projects implemented from 2006 to 2009, and water slope protection projects are basically intact; score +6;

Protection-8: The new bank revetment project implemented in 2010-2011 is in good condition now, with a score of +7.

3) Conditions and grades of river regime runoff external force conditions:

River-0: The river section where the monitoring section is located (range: 5km upstream of the upper end of the monitoring section to 3km downstream of the lower end of the monitoring section, the same below) the river regime is stable, and the monitoring area is not the main stream adjoining the bank, and the score is 0;

River-1: The river regime of the monitoring section is stable, and the straight transition section with seasonal adjoining flow is assigned a score of -1;

River-2: The river regime where the monitoring section is located is basically stable, and the seasonal adjoining flow tops the bend section, and the score is -2;

River-3: The river regime where the monitoring section is located has obvious adjustments, and the section of the river that sticks to the top and rushes over the bend all the year round is assigned a score of -3.

2. Grading terms for scour process characteristics

It is divided into the scour degree of the near-shore riverbed and the change of the underwater bank slope, and the total score is 0 to -10. Among them, the score of the scour degree of the near-shore riverbed (that is, the magnitude of scouring or deposition calculated in the above step B) is 0 to -7, the score of the underwater slope change (that is, the underwater slope ratio calculated in the above step C, and the variation range of the underwater slope toe slope ratio) is 0 to -3, and the scour process characteristics Items are scored using the principle of arithmetic summation. The following is an example of the scoring of the characteristic clauses of the flushing process as follows:

1) Grading terms of near-shore river bed scour degree:

Rush-0: During the period from May 2006 to October-December 2011, the sedimentation section at the front of the underwater slope toe is assigned a score of 0.

Rush-1: During the period from May 2006 to October-December 2011, the average sinking depth at the toe of the underwater slope is within 2.0m, and the maximum sinking depth is within 3.0m, and the score is -1;

Rush-2: During the period from May 2006 to October-December 2011, the average sinking depth at the toe of the underwater slope is 2.0-4.0m, and the maximum sinking depth is within 4.0-6.0m, assigned a score of -3;

Rush-3: From May 2006 to October-December 2011, the average sinking depth at the toe of the underwater slope was 4.0-6.0m; the maximum sinking depth was 6.0-9.0m, assigned a score of -5;

Rush-4: During the period from May 2006 to October-December 2011, the average sinking depth at the toe of the underwater slope is more than 6.0m; the maximum sinking depth is more than 9.0m, and the score is -7;

Chong-5: During the period from May 2006 to October-December 2010, the average sinking depth at the toe of the underwater slope was 4.0-6.0m. Scour, score -5;

Chong-6: Since September 1998, the scouring pit in Jitou has shown a trend of erosion and expansion. In 2011, the area of the scouring pit reached or approached the maximum value since records were recorded, and the score was -7;

Chong-7: Since September 1998, the Jitou scour pit has shown a trend of scour depth. In 2011, the elevation of the lowest point of the scour pit reached or was close to the lowest point ever recorded, and the score was -7;

2) Gradation clauses for near-shore riverbed slope conditions:

Slope-1: From October 2007 to December 2011, the average slope value of the underwater slope was less than 0.33 (1:3), and there was no steepening trend in the past 3 years; the inner slope at the foot of the slope was gentle, with a score of 0;

Slope-2: During the period from October 2007 to December 2011, the average slope value of the underwater slope was less than 0.33 (1:3), and there was a tendency to become steeper in the past three years; or the inner slope at the foot of the slope tended to become steeper; assigned a value -1;

Slope-3: From October 2007 to December 2011, the average slope value of the underwater slope was 0.33-0.5 (1:2), and there was no steepening trend in the past 3 years; -2;

Slope-4: During the period from October 2007 to December 2011, the inner slope at the foot of the underwater slope has become steeper in the past three years, and the score is -2.

Slope-5: During the period from October 2007 to December 2011, the average slope value of the underwater slope was greater than 0.5 (1:2), and there was a tendency to become steeper in the past three years, and the score was -3.

3. Scoring clauses for shoreline condition characteristics

It is the case of bankline collapse, which is the result of concentrated explosion of bankline stability risks, and the score of the shoreline condition characteristic item (riverline collapse) is 0 to -10. The following is an example of assigning points to the characteristics of shoreline conditions as follows:

Collapse-0: There has been no bank collapse in the last 5 years (hydrological year, the same below) in the section without revetment, and there has been no obvious water damage or slope slippage in the section with revetment in the last 5 years, and the score is 0;

Collapse-1: 200m away from the embankment project, a small number of bank collapse points have occurred in the section without revetment in the last 3 years; a small amount of water damage or hanging sills at the front of the dry water platform have occurred in the section with revetment in the last 3 years, and the bank collapse points have not been repaired, and the points are assigned value -2;

Collapse-2: 200m away from the embankment project, a small number of bank collapse points have occurred in the section without bank revetment in the last 3 years; a small amount of water damage or bank slide has occurred in the section with bank revetment in the last 3 years, and the bank collapse points have not been repaired, and the score is - 3;

Collapse-3: 100-200m away from the embankment project, many bank collapse points have occurred in the section without bank revetment in the past 3 years, and a small amount of bank slide has occurred in the section with bank revetment in the past 3 years. Within the range of , assign a value of -4;

Collapse-4: 100-200m away from the embankment project, there have been many bank collapse points in the section without bank revetment in the past 3 years, and a small number of bank slopes or dry water platform slides in the section with bank protection in the past 3 years, bank collapse or bank slope slide points Within the range of 250m upstream and downstream, the score is -5;

Collapse-5: Within 100 meters away from the embankment project, there are many bank collapse points in the first 3 years in the section without bank revetment, and a small amount of bank collapse in the past 3 years in the section with bank revetment. Within the range, the score is -6;

Collapse -6: 200m away from the main dike project, there have been a large number of bank collapse points in the last 3 years in the section without revetment, and the score is -7;

Collapse -7: 200m away from the embankment project, there have been a large number of bank collapse points in the last 3 years in the section without revetment, and the score is -6;

Collapse-8: Within 100 meters away from the embankment project, there are many bank collapse points in the first 3 years in the section without bank revetment, and a small amount of bank slope or dry water platform slippage in the first 3 years in the section with bank revetment, and the bank collapse or bank slope slide point Within the range of 250m downstream, the score is -7;

Collapse -9: Bank collapse occurs in that year, and the shoreline within 100m from the embankment project is assigned a score of -7.

Collapse -10: The coastline within 100m from the embankment project in the current year is given a score of -8.

Collapse -11: A score of -9 is assigned to shorelines within 50m of civil embankment projects where bank collapse or bank slope slippage occurred in the year.

Collapse -12: A score of -10 is assigned to shorelines within 50m of the embankment project in the current year when there is bank collapse or bank slope slippage.

Calculation Method of Comprehensive Score for Slope Stability

According to the factors that affect the bank slope stability risk and the characteristics of the risk at different stages, it is divided into conditional characteristic clauses, scour process characteristic clauses and shoreline condition characteristic clauses. 30%) and result terms (weight 40%) weighted average method to evaluate the bankline stability. See Table 1.

Table 1 Score evaluation weight distribution table of slope stability factors

Clause name condition feature clause Flushing Process Characteristic Clause Shoreline Condition Characteristics Clause Weights 30% 30% 40%

Risk classification method for river bank slope stability

Comprehensive assessment of the bank slope stability risk level of the monitored bank section According to the comprehensive assessment score of the bank slope stability of the monitored bank section and corresponding to the actual situation of each bank section, the range of comprehensive assessment score value of the bank slope stability risk level of the river course is determined, as shown in Table 2.

Table 2 Statistical table of score range of comprehensive assessment of river bank slope stability risk level

Stability Risk Level General section Secondary fortification shore section First-level fortification coast section Warning section Color warning prompt green shore section blue shore section Coastal section of orange warning Coastal section of red warning Comprehensive score range Greater than 0 0～-2.0 -2.0～-3.0 Less than -3.0

In accordance with the above-mentioned rules for classification and grading of risk factors affecting bank stability, and compared with the specific conditions of the North Gate section, comprehensively evaluate the bank slope condition characteristics, scour process characteristics, and shoreline condition characteristics of the bank slope stability of the river bank. Score. See Table 3 for details.

Table 3 Statistical table of assigned scores for risk impact assessment of river bank slope stability in Beimenkou section

The stability grade of the river bank slope of the North Gate section is divided according to the score range of the comprehensive assessment of the river bank slope stability risk level in Table 2 and the assessment score value of the North Gate section of the river bank slope stability risk impact assessment in Table 3. See Table 4 for details.

Table 4 Statistical Table of Stability Levels of River Bank Slopes in North Gate Section

Applications

At present, this method has begun to be applied to the river regime monitoring and analysis of the Jingjiang section of the middle reaches of the Yangtze River, to analyze and evaluate the impact of the Three Gorges Reservoir on the stability of the Jingjiang river bank after the water storage is used, and to provide services for the prevention and control planning of river bank collapse disasters.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any changes or substitutions that can be easily imagined by those skilled in the art within the technical scope disclosed in the present invention, All should be covered within the protection scope of the present invention.

Claims (5)

1. bank stabilization property monitoring analysis and appraisal procedure is characterized in that comprising the steps:

Steps A: set up based on the monitoring lead of offshore bed configuration figure and the Monitoring Data collection network of offshore river bed water descending slope analysis section; Wherein monitoring lead has 3, is respectively the monitoring lead that dash to become silted up, slope monitoring starting point lead, slope monitoring terminal point lead under water under water; Gradient analysis section is arranged on demand under water, and general 50～300m at interval arranges 1 monitoring analysis section;

Step B: offshore bed configuration figure is a basic document with the river course; The topomap that liquidating silt monitoring lead belongs to position, offshore riverbed, river course carries out digitized processing; According to the outcome data data that is obtained; Draw and dash the bed elevation variation relation figure of silt monitoring lead, and calculate each segmentation elevation change mean value along Parallel to the flow direction;

Step C: offshore bed configuration figure is a basic document with the river course; The topomap that the intersection point of the monitoring analysis section of monitoring lead and vertical streamflow direction is belonged to position, offshore riverbed, river course carries out digitized processing; According to the outcome data data that is obtained; Draw the variation relation figure of side slope under the offshore river bed water, toe inner slope slope ratio longshore current journey, and calculate each segmentation slope average of relatives value;

Step D: according to above-mentioned analysis results; And combine the geological boundry condition on riverbank and river gesture runoff external force condition, water front situation and river, section, analysis and evaluation bank section place gesture to develop key element; By bank stabilization venture influence factor classification grade scoring detailed rules and regulations; Analysis and evaluation bank section is carried out classification grade compose branch, calculate the comprehensive score value of composing then, wherein river course bank slope geologic structure and shore protection situation are to influence the stable geological boundry condition of bank line; By comprehensive interval of composing score value place bank stability property risk class, confirm the bank stability property risk class in corresponding location.

2. bank stabilization property monitoring analysis as claimed in claim 1 and appraisal procedure; It is characterized in that: take all factors into consideration following content element when confirming the said plane coordinates position that dashes the monitoring lead that becomes silted up in the said steps A: 1. to the location of bank-protection works under water, river course is arranged, the planimetric position that dashes the monitoring lead that becomes silted up is apart from 5～30 meters of the outer rims of channel revetment Underwater Engineering; 2. do not have the channel revetment location of bank-protection works under water, the inward flange line-spacing of pressing the offshore deep trouth width of average low water bit line for many years confirms to dash the planimetric position of monitoring lead of becoming silted up, and the planimetric position that dashes the monitoring lead that becomes silted up is apart from average low water bit line 60-150 rice for many years; 3. consider simultaneously river course low water level flowage line irregularity and low water season the offshore main stream line smooth and easy, suitably the planimetric position of the monitoring lead that becomes silted up is dashed in adjustment, makes that to dash the monitoring lead that becomes silted up smooth and easy; Take all factors into consideration following content element when confirming the plane coordinates position of the said starting point of slope monitoring under water lead in the said steps A: the bed elevation of the position, reference mark on the lead is lower than average for many years low water level 2～3m; Take all factors into consideration following content element when confirming the plane coordinates position of the said terminal point of slope monitoring under water lead in the said steps A: the position, reference mark on the lead is that near the fracture morphology the toe changes near " flex point ".

3. bank stabilization property monitoring analysis as claimed in claim 1 and appraisal procedure is characterized in that: said step B specifically comprises:

Data acquisition: the point to dash a setting on the monitoring lead that becomes silted up is an initial point, and corresponding embankment bank-protection works pile No. is gathered a height value at a certain distance along the monitoring lead;

Data processing: utilize EXCEL, AUTOCAD program to draw and dash the monitoring lead elevation that becomes silted up along the journey variation diagram; Analyze dashing of different times and become silted up monitoring lead place bed elevation, calculate the amplitude of washing away or depositing by dashing the monitoring lead place's bed elevation variation characteristic segmentation of becoming silted up along the journey variation diagram.

4. bank stabilization property monitoring analysis as claimed in claim 1 and appraisal procedure is characterized in that: said step C specifically comprises:

Data acquisition: the sloping under water ratio of monitoring section is that the segmental averaging of river course offshore slope is generally changed; Offshore slope is divided into side slope and toe inner slope under water under water, side slope scope under water: slope monitoring starting point lead to the zone between slope monitoring terminal point lead under water under water; Toe inner slope scope under water: slope monitoring terminal point lead is to dashing the zone of becoming silted up between the monitoring lead under water; Monitoring section line and slope monitoring starting point lead under water, the intersection point of slope monitoring terminal point lead be the raw data acquisition point of the sloping ratio of side slope under water under water; Bed elevation according to 2 intersection points of gathering calculates relevant monitoring section side slope slope ratio under water with level interval; The monitoring section line with slope monitoring terminal point lead under water, the intersection point that dashes the monitoring lead that becomes silted up be the raw data acquisition point of toe inner slope slope ratio under water, according to the bed elevation of 2 intersection points of gathering and the relevant monitoring section of the level interval calculating sloping ratio of toe inner slope under water;

Data processing: calculate the side slope under water slope ratio of each monitoring section, toe inner slope slope ratio under water, utilize that EXCEL, AUTOCAD program are drawn under water side slope slope ratio, toe inner slope slope ratio is along the journey variation diagram under water; The sloping ratio of analyzing different times is along the journey variation diagram, calculates than variation characteristic segmentation by the slope and divides section side slope slope ratio, the amplitude of variation of toe inner slope slope ratio under water under water.

5. bank stabilization property monitoring analysis as claimed in claim 1 and appraisal procedure; It is characterized in that: said bank stability risk assessment is divided into 4 grades: general, secondary is set up defences, one-level is set up defences, alert level, and corresponding color tips is respectively: green bank section, blue bank section, orange early warning bank section, red early warning bank section.

Images