Strong unloading fractured rock slope instability risk assessment method and system

Abstract

The invention relates to the technical field of hydroelectric and hydraulic engineering water ecological protection, and discloses a strong unloading fractured rock mass slope instability risk assessment method and system.The method comprises the steps that unloading fracture distribution characteristics are divided into a plurality of independent assessment units, and each assessment unit is provided with at least one set of field monitoring point positions in advance; the method comprises the following steps: performing coupling analysis on multi-dimensional monitoring information of a field monitoring point position, establishing an association relationship among the multi-dimensional monitoring information, determining a dominant disturbance factor influencing the slope stability in an evaluation unit, constructing an instability risk association function of the evaluation unit, outputting a real-time risk coefficient of the evaluation unit, and determining the stability of the slope in the evaluation unit. Calculating a risk coefficient difference value between the adjacent evaluation units and a risk transfer potential value between the adjacent evaluation units, judging whether a risk transfer channel exists between the adjacent evaluation units, and generating an instability risk evaluation result of the slope in combination with the real-time risk coefficient of each evaluation unit; according to the method, the key influence factors of slope instability and the coverage risk transmission path can be accurately identified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water power and water conservancy ecological protection, and particularly relates to a strong unloading broken rock mass slope instability risk assessment method and system. BACKGROUND

[0002] In the construction of water conservancy hubs, open-pit mines, highway / railway cuts and other engineering projects, strong unloading broken rock mass slopes are a typical high-risk engineering object. Due to unloading effects such as engineering excavation and geological structure movement, the rock mass of such slopes produces a large number of through-going fissures, and the structural integrity of the rock mass is severely damaged, with a significant reduction in shear strength and bearing capacity. At the same time, the slope is exposed to the natural environment for a long time, and is easily disturbed by external factors such as rainfall infiltration, groundwater level fluctuation, and blasting vibration, resulting in continuous changes in the internal stress state of the rock mass and continuous expansion of the fissures, eventually leading to sudden instability disasters such as landslides and collapses. According to engineering statistics, strong unloading broken rock mass slope instability accidents not only cause equipment damage and project shutdown, but also threaten the safety of personnel, with a single accident often causing economic losses of several million yuan or more, so accurate assessment of the instability risk of such slopes has become a core requirement of engineering safety management.

[0003] Current engineering field methods for assessing the risk of slope instability are mostly based on traditional rock mechanics theory or a single monitoring index, and are difficult to adapt to the complex characteristics of strong unloading broken rock mass. Some evaluation methods rely only on slope geometric parameters (such as slope ratio and slope height) or static rock mechanics parameters (such as cohesion and internal friction angle) for stability calculation, ignoring the dynamic evolution law of the rock mass structure under unloading and the coupling effect of external disturbance factors, resulting in a large deviation between the evaluation results and the actual risk. Other methods introduce monitoring data, but mostly focus on single-dimensional displacement monitoring, without establishing a correlation between stress, fissure, and micro-vibration monitoring information, and are unable to identify key disturbance factors affecting slope instability, making it difficult to capture instability precursors in advance, and the timeliness and accuracy of the evaluation cannot meet engineering requirements.

[0004] The existing evaluation system also has the defect of inadequate description of risk transmission rules. The instability of a strong unloading broken rock mass slope does not occur independently in a single area, but is a process in which the risk of a high-risk area is transmitted and diffused to surrounding low-risk areas through through-going fissures. However, current methods mostly judge the risk of the slope as a whole or as an isolated unit, without considering the influence of risk gradient differences and fissure connectivity between adjacent areas on risk transmission, and are unable to construct a complete risk transmission path, resulting in evaluation results that can only locate high-risk areas, but cannot predict the range and speed of risk diffusion. This limitation makes it difficult for engineering protection measures to accurately cover the risk transmission path, and when a slope instability disaster occurs, it is easy to cause the disaster area to expand due to lagging protection, For example, patent document CN111598406B discloses a quantitative assessment method for the instability risk of blocks on steep slopes, including the following steps: S1, numbering each unstable body on the steep slope in sequence; S2, analyzing and calculating the stability coefficient, volume, relative height, affected objects, and contact frequency characteristics of each block; S3, establishing risk assessment factor weight coefficients ai and scoring standards based on engineering characteristics, and assigning scores xi to the risk assessment factors based on the block characteristic values ​​calculated in step S2; S4, calculating the risk value f(x) = ∑(ai × xi) for each risk assessment factor, which is the sum of the products of the weight coefficients ai and the factor scores xi for each risk assessment factor, and classifying the instability risk of the unstable body according to the risk value. This technical solution assesses each unstable body on the steep slope separately, but does not construct a complete risk transmission path, making it difficult to accurately cover the risk transmission path. Therefore, there is an urgent need to design a technical solution for slope instability assessment that can accurately identify the key influencing factors of slope instability in strongly unloaded fractured rock masses and construct a complete risk transmission path. Summary of the Invention

[0005] To address the technical problems of existing technologies being unable to adapt to the complex characteristics of heavily unloaded fractured rock masses, failing to construct complete risk transmission paths, resulting in assessment results that can only locate high-risk areas and cannot accurately cover risk transmission paths or predict the scope and speed of risk diffusion, a method for assessing the instability risk of heavily unloaded fractured rock mass slopes is provided, comprising the following steps: The distribution characteristics of unloading fractures in a strongly unloaded fractured rock slope are determined, and the distribution characteristics of unloading fractures are divided into several independent evaluation units. Each evaluation unit has at least one set of field monitoring points. The distribution characteristics of unloading fractures are that there are dense fracture areas and sparse fracture isolated areas within the same slope. A coupled analysis is performed on the multi-dimensional monitoring information of the field monitoring points for a specified duration to establish the correlation between the multi-dimensional monitoring information and determine the dominant disturbance factor affecting slope stability in each evaluation unit; the multi-dimensional monitoring information includes information on stress change inside the rock mass, information on crack opening and closing degree change, and information on micro-vibration of the slope surface; Based on the dominant disturbance factor, an instability risk correlation function for the assessment unit is constructed, and the real-time risk coefficient of the assessment unit is output. Calculate the risk coefficient difference between adjacent assessment units. Where i and j represent adjacent evaluation units; Based on the distribution characteristics of unloading cracks, the crack connectivity parameters between adjacent evaluation units are determined. Combined with the risk coefficient difference Calculate the risk transmission potential value between adjacent assessment units. Determine whether there is a risk transmission channel between the adjacent assessment units; Based on the judgment results of the risk transmission channel, combined with the real-time risk coefficient of each assessment unit... The results of the instability risk assessment of the strongly unloaded fractured rock slope are generated. The assessment results include at least the location of the high-risk assessment unit, the risk transmission path, and the overall slope instability warning level.

[0006] Furthermore, the method for determining whether a risk transmission channel exists between adjacent assessment units includes the following: Set risk transmission threshold Calculate the risk transmission potential value between adjacent assessment units. ; like If so, it is determined that there is a risk transmission channel between the adjacent assessment units, and the risk transmission direction of the risk transmission channel is from the high-risk coefficient assessment unit to the low-risk coefficient assessment unit. Among them, the risk transmission potential value between adjacent assessment units The calculation expression is: , The higher real-time risk coefficient among the adjacent evaluation units .

[0007] Furthermore, the overall slope instability warning level is classified according to the overall slope risk index S, and the calculation expression for the overall slope risk index S is as follows: ; in, The number of high-risk assessment units, This represents the total number of slope assessment units. This is the sum of the transmission potential values ​​of all risk transmission channels. The total number of risk transmission channels. , These are the corresponding weighting coefficients.

[0008] Furthermore, the process of establishing the correlation between the multi-dimensional monitoring information includes the following: The multi-dimensional monitoring information is standardized, and a mutual information coupling model is used to calculate the correlation degree between any two types of monitoring information. A correlation matrix is ​​constructed, and the correlation relationships between the multi-dimensional monitoring information are established through the correlation matrix. The correlation degree is the mutual information value calculated by the mutual information coupling model. ; in, , For any two types of monitoring information.

[0009] Furthermore, the mutual information value The expression is: ; in, for Take the first Values ​​and Take the first The joint probability of each value They are respectively Take the first individual values Take the first The marginal probability of each value The number of sampling points for monitoring data within a specified time period.

[0010] Furthermore, the method for determining the dominant perturbation factor includes the following: Based on the correlation matrix, a set of potential disturbance factors that are correlated with all the multi-dimensional monitoring information is selected. A disturbance factor contribution calculation model is constructed to calculate the contribution of each potential disturbance factor to the multi-dimensional monitoring information. Set the contribution threshold as When the contribution ≥ The contribution threshold If so, the current potential disturbance factor is determined as the dominant disturbance factor affecting slope stability within the current assessment unit.

[0011] Furthermore, the real-time risk coefficient of the evaluation unit The calculation method includes the following: Obtain the rate of change of the determined dominant disturbance factor at the current moment, input the rate of change into the instability risk correlation function, and calculate the real-time risk coefficient through the instability risk correlation function. The real-time risk coefficient The calculation expression is: ; in, This represents the number of dominant disturbance factors within the current evaluation unit. For the first The weighting coefficients of the dominant disturbance factors, For the first The dominant disturbance factors at time rate of change, For the first Sensitivity index of the dominant disturbance factor.

[0012] Furthermore, the risk coefficient difference between adjacent assessment units The calculation expression is: ; in, As an evaluation unit and The straight-line distance between the center points of the boundary. The characteristic length parameter of a strongly unloaded fractured rock slope.

[0013] Furthermore, the risk transmission path is determined by constructing a directed risk transmission network, and the method for constructing the directed risk transmission network includes: Set risk transmission threshold ; Starting with all the high-risk assessment units as initial nodes, traverse all identified risk transmission channels, establish directed edges for each risk transmission channel according to the risk transmission direction, and calculate the risk transmission value for each non-high-risk unit. ; when When the current unit is incorporated into the risk transmission network and used as an intermediate node, the process is repeated iteratively to form a directed risk transmission network.

[0014] The present invention also provides a risk assessment system for the instability of a strongly unloaded fractured rock slope, which is implemented by the aforementioned risk assessment method for the instability of a strongly unloaded fractured rock slope. The risk assessment system for the instability of a strongly unloaded fractured rock slope includes a monitoring and acquisition unit, a dominant factor identification unit, a risk transmission calculation unit, and an assessment result generation unit. The monitoring and acquisition unit is used to collect multi-dimensional monitoring information data of the strongly unloaded fractured rock slope and spatial attribution information data of the on-site monitoring points, and transmit them synchronously to the dominant factor identification unit. The dominant factor identification unit is used to receive data transmitted by the monitoring and acquisition unit, determine the dominant disturbance factor and standardize the multi-dimensional monitoring information data, and transmit the dominant disturbance factor information data and the standardized multi-dimensional monitoring information data to the risk transmission calculation unit. The risk transmission calculation unit is used to receive data transmitted by the dominant factor identification unit and calculate the real-time risk coefficient. And determine the risk transmission channel, and transfer the real-time risk coefficient. The risk transmission channel judgment result is transmitted to the assessment result generation unit; the risk transmission channel judgment result includes risk transmission channel and transmission direction information; The evaluation result generation unit is used to receive the real-time risk coefficient transmitted by the risk transfer calculation unit. Based on the risk transmission channel assessment results, a risk assessment report on the instability of a strongly unloaded fractured rock slope is generated. The risk assessment report includes the location of high-risk units, risk transmission paths, warning levels, and quantitative data.

[0015] The beneficial effects of this invention are: (1) This invention performs coupled analysis on multi-dimensional monitoring information such as internal stress of rock mass, crack opening and closing degree, and micro-vibration of slope surface, constructs a correlation matrix by combining mutual information coupling model, and then screens the dominant disturbance factors by contribution calculation model. This can effectively eliminate the interference of secondary factors, focus on the core factors that play a decisive role in slope stability, avoid the assessment deviation caused by the ambiguity of factor identification in traditional methods, provide accurate parameter basis for subsequent risk calculation, make the assessment process more in line with the actual instability mechanism of strongly unloaded fractured rock mass, accurately identify the key influencing factors of slope instability of strongly unloaded fractured rock mass, and greatly improve the pertinence of risk assessment.

[0016] (2) This invention constructs an instability risk correlation function based on the dominant disturbance factor, and calculates the real-time risk coefficient by taking the real-time change rate of the factor as input. It can dynamically reflect the evolution trend of slope risk over time, capture subtle risk changes in the process of slope from stability to instability in real time, detect abnormal risk fluctuations in time, identify instability precursors in advance, and give engineers more time for emergency response. It can effectively reduce the passivity of disaster prevention and control caused by assessment lag. It realizes the dynamic quantification of real-time risk of strongly unloaded fractured rock slope, and significantly improves the timeliness and accuracy of assessment.

[0017] (3) This invention calculates the risk coefficient difference between adjacent assessment units and determines the risk transmission channel by combining the fracture connectivity parameter. It constructs a directed risk transmission network, which can intuitively present the risk diffusion path and transmission potential from high-risk areas to low-risk areas. This allows engineers to clearly grasp the scope and direction of risk diffusion, providing clear guidance for targeted deployment of protective measures and blocking of risk transmission, and improving the accuracy of slope disaster prevention and control. It can clearly depict the risk transmission law of strongly unloaded fractured rock slopes, filling the gap in the existing assessment system for depicting risk diffusion.

[0018] (4) The comprehensive assessment results generated by this invention can provide comprehensive and practical decision support for the safety management of strongly unloaded fractured rock slopes. It not only includes the location of high-risk units and risk transmission paths, but also divides the early warning level by calculating the overall risk index, which makes it easy for engineers to quickly locate the core risk area and formulate differentiated prevention and control strategies according to the early warning level. At the same time, it provides data support for subsequent slope reinforcement and monitoring scheme optimization, realizes the closed loop from risk assessment to safety control, and significantly improves the safety management level of strongly unloaded fractured rock slope engineering. Attached Figure Description

[0019] Figure 1This is a flowchart of the method for assessing the instability risk of strongly unloaded fractured rock slopes provided by the present invention; Figure 2 This is a distribution diagram of the nodes in the directed risk transmission network provided by the present invention; Figure 3 This is a structural diagram of the high-unloading fractured rock slope instability risk assessment system provided by the present invention. Detailed Implementation

[0020] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0021] This invention provides a method for assessing the instability risk of a strongly unloaded fractured rock slope, such as... Figure 1 As shown, it includes the following steps: Step S100: Determine the distribution characteristics of unloading fractures in the strongly unloaded fractured rock slope, and divide the distribution characteristics of unloading fractures into several independent evaluation units. Each evaluation unit shall have at least one set of field monitoring points. The distribution characteristics of unloading fractures are that there are dense fracture areas and sparse fracture isolated areas in the same slope. Step S200: Perform coupled analysis on the multi-dimensional monitoring information of the field monitoring points for a specified duration, establish the correlation between the multi-dimensional monitoring information, and determine the dominant disturbance factor affecting slope stability within each evaluation unit; the multi-dimensional monitoring information includes information on stress changes within the rock mass, information on changes in the opening and closing degree of fractures, and information on micro-vibrations on the slope surface; the dominant disturbance factor is a factor whose contribution to both stress changes and fracture opening and closing degree changes within the specified duration exceeds a preset threshold; The process of establishing the correlation between the multi-dimensional monitoring information includes the following: The multi-dimensional monitoring information is standardized, and a mutual information coupling model is used to calculate the correlation degree between any two types of monitoring information. A correlation matrix is ​​constructed, and the correlation relationships between the multi-dimensional monitoring information are established through the correlation matrix. The correlation degree is the mutual information value calculated by the mutual information coupling model. ; in, , For any two types of monitoring information.

[0022] The mutual information value The expression is: ; in, for Take the first Values ​​and Take the first The joint probability of each value They are respectively Take the first individual values Take the first The marginal probability of each value The number of sampling points for monitoring data within a specified time period.

[0023] The method for determining the dominant perturbation factor includes the following: Based on the correlation matrix, a set of potential disturbance factors that are correlated with all the multi-dimensional monitoring information is selected. A disturbance factor contribution calculation model is constructed to calculate the contribution of each potential disturbance factor to the multi-dimensional monitoring information. The contribution The calculation expression is: ; in, Perturbation factor The rate of change over a specified period of time. The total number of potential disturbance factors. For the first Standardized values ​​of the potential disturbance factors; Set the contribution threshold as When the contribution ≥ The contribution threshold If so, the current potential disturbance factor is determined as the dominant disturbance factor affecting slope stability within the current assessment unit.

[0024] Step S300: Based on the dominant disturbance factor, construct the instability risk correlation function of the evaluation unit and output the real-time risk coefficient of the evaluation unit. Calculate the risk coefficient difference between adjacent assessment units. Where i and j represent adjacent evaluation units; The real-time risk coefficient of the evaluation unit The calculation method includes the following: Obtain the rate of change of the determined dominant disturbance factor at the current moment, input the rate of change into the instability risk correlation function, and calculate the real-time risk coefficient through the instability risk correlation function. The real-time risk coefficient The calculation expression is: ; in, This represents the number of dominant disturbance factors within the current evaluation unit. For the first The weighting coefficients of the dominant disturbance factors, For the first The dominant disturbance factors at time rate of change, For the first Sensitivity index of the dominant disturbance factor.

[0025] Step S400: Based on the unloading crack distribution characteristics, determine the crack connectivity parameters between adjacent evaluation units. Combined with the risk coefficient difference Calculate the risk transmission potential value between adjacent assessment units. Determine whether there is a risk transmission channel between the adjacent assessment units; The method for determining whether there is a risk transmission channel between adjacent assessment units includes the following: Set risk transmission threshold Calculate the risk transmission potential value between adjacent assessment units. ; like If so, it is determined that there is a risk transmission channel between the adjacent assessment units, and the risk transmission direction of the risk transmission channel is from the high-risk coefficient assessment unit to the low-risk coefficient assessment unit. Among them, the risk transmission potential value between adjacent assessment units The calculation expression is: ; in, The higher real-time risk coefficient among the adjacent evaluation units .

[0026] The risk coefficient difference between adjacent assessment units The calculation expression is: ; in, As an evaluation unit and The straight-line distance between the center points of the boundary. The characteristic length parameter of a strongly unloaded fractured rock slope.

[0027] Step S500: Based on the judgment result of the risk transmission channel, and combined with the real-time risk coefficient of each evaluation unit... The results of the instability risk assessment of the strongly unloaded fractured rock slope are generated. The assessment results include at least the location of the high-risk assessment unit, the risk transmission path, and the overall slope instability warning level. Where i and j represent adjacent evaluation units.

[0028] The overall slope instability warning level is classified according to the overall slope risk index S, and the calculation expression for the overall slope risk index S is as follows: ; in, The number of high-risk assessment units, This represents the total number of slope assessment units. This is the sum of the transmission potential values ​​of all risk transmission channels. The total number of risk transmission channels. , These are the corresponding weighting coefficients.

[0029] In this embodiment, the risk transmission path is determined by constructing a directed risk transmission network, and the method for constructing the directed risk transmission network includes: Set risk transmission threshold ; Starting with all the high-risk assessment units as initial nodes, traverse all identified risk transmission channels, establish directed edges for each risk transmission channel according to the risk transmission direction, and calculate the risk transmission value for each non-high-risk unit. The risk transmission value The calculation expression is: ; in, For non-high-risk units Upstream units with risk transmission channels Real-time risk coefficient, For unit and The potential value of risk transmission between them Let be the connectivity length between the two unit boundaries. This is the risk attenuation coefficient. For all units A set of units with upstream risk transmission relationships.

[0030] when When the current unit is incorporated into the risk propagation network and used as an intermediate node, the process is repeated iteratively to form a directed risk propagation network. The node distribution of the directed risk propagation network is as follows: Figure 2 As shown.

[0031] This invention describes in detail how to accurately identify the dominant disturbance factors of slope instability, dynamically quantify real-time risk coefficients, clearly depict the risk transmission path, and generate a comprehensive result including high-risk locations, transmission directions, and warning levels. This solves the problems of vague factor identification, lagging static assessment, and insufficient risk transmission characterization in traditional methods, and provides accurate and efficient decision support for the safety management of strongly unloaded fractured rock slopes.

[0032] This invention also provides a risk assessment system for the instability of strongly unloaded fractured rock slopes, implemented using the aforementioned risk assessment method for the instability of strongly unloaded fractured rock slopes, such as... Figure 3 As shown, the high-unloading fractured rock slope instability risk assessment system includes a monitoring and acquisition unit, a dominant factor identification unit, a risk transmission calculation unit, and an assessment result generation unit. The monitoring and acquisition unit is used to collect multi-dimensional monitoring information data of the strongly unloaded fractured rock slope and spatial attribution information data of the on-site monitoring points, and transmit them synchronously to the dominant factor identification unit. Specifically, the monitoring and acquisition unit does not participate in data processing and calculation. By deploying stress sensors, crack opening and closing sensors, micro-vibration sensors, rain gauges and groundwater level gauges at preset monitoring points on the slope, it collects real-time data on stress changes inside the rock mass, crack opening and closing changes, micro-vibration data on the slope surface, rainfall data and groundwater level data. All original monitoring data and the spatial attribution information (to which the corresponding evaluation unit) of the corresponding monitoring points are synchronously transmitted to the dominant factor identification unit.

[0033] The dominant factor identification unit is used to receive data transmitted by the monitoring and acquisition unit, determine the dominant disturbance factor and standardize the multi-dimensional monitoring information data, and transmit the dominant disturbance factor information data and the standardized multi-dimensional monitoring information data to the risk transmission calculation unit. Specifically, the dominant factor identification unit receives the raw data transmitted by the monitoring and acquisition unit, first standardizes the data (eliminating dimensional differences), then constructs a monitoring information correlation matrix through a mutual information coupling model, filters potential disturbance factors that are related to stress and crack changes based on the matrix, and finally determines the dominant disturbance factor of each assessment unit through a disturbance factor contribution calculation model (quantifying the contribution of each factor to stress and crack changes), and transmits the dominant disturbance factor information and the standardized monitoring data to the risk transmission calculation unit.

[0034] The risk transmission calculation unit is used to receive data transmitted by the dominant factor identification unit and calculate the real-time risk coefficient. And determine the risk transmission channel, and transfer the real-time risk coefficient. The risk transmission channel judgment result is transmitted to the assessment result generation unit; the risk transmission channel judgment result includes risk transmission channel and transmission direction information; Specifically, the risk transmission calculation unit does not participate in result integration. It receives the output information data from the dominant factor identification unit, first constructs the instability risk correlation function of each assessment unit based on the dominant disturbance factor, and calculates the real-time risk coefficient of each unit by inputting the real-time change rate of the dominant disturbance factor into the function. Then, it calculates the risk coefficient difference between adjacent assessment units based on the real-time risk coefficient (combined with unit spatial distance correction), and determines the risk transmission channel and transmission direction by combining the slope unloading crack connectivity parameter. The real-time risk coefficient, risk transmission channel and transmission direction information are then transmitted to the assessment result generation unit. The evaluation result generation unit is used to receive the real-time risk coefficient transmitted by the risk transfer calculation unit. Based on the risk transmission channel assessment results, a risk assessment report on the instability of a strongly unloaded fractured rock slope is generated. The risk assessment report includes the location of high-risk units, risk transmission paths, warning levels, and quantitative data.

[0035] Specifically, the assessment result generation unit does not participate in front-end data collection or calculation, but receives the output information from the risk transmission calculation unit and generates the result through the following steps: ① Identify high-risk assessment units (mark units whose risk coefficients reach a preset threshold); ② Starting from high-risk units, construct a directed risk transmission network along the transmission direction; ③ Calculate the overall risk index of the slope and classify the warning levels; generate an assessment report that includes the location of high-risk units, risk transmission paths, warning levels and quantitative data, and complete the slope instability risk assessment.

[0036] This invention describes in detail how a four-unit collaborative approach—monitoring and data collection, identification of dominant factors, risk transmission calculation, and assessment result generation—can accurately acquire multi-dimensional data, locate dominant disturbance factors, quantify real-time risks and transmission channels, and output a comprehensive assessment report. This addresses the problems of poor targeting and insufficient timeliness in traditional assessments, providing efficient support for the safety management of strongly unloaded fractured rock slopes.

[0037] The above-disclosed embodiments are merely specific examples of the present invention. However, the present invention is not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A method for assessing the instability risk of a strongly unloaded fractured rock slope, characterized in that, Includes the following steps: The distribution characteristics of unloading fractures in a strongly unloaded fractured rock slope are determined, and the distribution characteristics of unloading fractures are divided into several independent evaluation units. Each evaluation unit has at least one set of field monitoring points. The distribution characteristics of unloading fractures are that there are dense fracture areas and sparse fracture isolated areas within the same slope. A coupled analysis is performed on the multi-dimensional monitoring information of the field monitoring points for a specified duration to establish the correlation between the multi-dimensional monitoring information and determine the dominant disturbance factor affecting slope stability in each evaluation unit. The multi-dimensional monitoring information includes information on stress changes inside the rock mass, changes in the opening and closing of cracks, and micro-vibration information on the slope surface; Based on the dominant disturbance factor, an instability risk correlation function for the assessment unit is constructed, and the real-time risk coefficient of the assessment unit is output. Calculate the risk coefficient difference between adjacent assessment units. Where i and j represent adjacent evaluation units; Based on the distribution characteristics of unloading cracks, the crack connectivity parameters between adjacent evaluation units are determined. Combined with the risk coefficient difference Calculate the risk transmission potential value between adjacent assessment units. Determine whether there is a risk transmission channel between the adjacent assessment units; Based on the judgment results of the risk transmission channel, combined with the real-time risk coefficient of each assessment unit... The results of the instability risk assessment of the strongly unloaded fractured rock slope are generated. The assessment results include at least the location of the high-risk assessment unit, the risk transmission path, and the overall slope instability warning level.

2. The method for assessing the instability risk of strongly unloaded fractured rock slopes as described in claim 1, characterized in that, The method for determining whether there is a risk transmission channel between adjacent assessment units includes the following: Set risk transmission threshold Calculate the risk transmission potential value between adjacent assessment units. ; like If so, it is determined that there is a risk transmission channel between the adjacent assessment units, and the risk transmission direction of the risk transmission channel is from the high-risk coefficient assessment unit to the low-risk coefficient assessment unit. Among them, the risk transmission potential value between adjacent assessment units The calculation expression is: , The higher real-time risk coefficient among the adjacent evaluation units .

3. The method for assessing the instability risk of strongly unloaded fractured rock slopes as described in claim 2, characterized in that, The overall slope instability warning level is classified according to the overall slope risk index S, and the calculation expression for the overall slope risk index S is as follows: ； in, The number of high-risk assessment units, This represents the total number of slope assessment units. This is the sum of the transmission potential values ​​of all risk transmission channels. The total number of risk transmission channels. , These are the corresponding weighting coefficients.

4. The method for assessing the instability risk of strongly unloaded fractured rock slopes as described in claim 3, characterized in that, The process of establishing the correlation between the multi-dimensional monitoring information includes the following: The multi-dimensional monitoring information is standardized, and a mutual information coupling model is used to calculate the correlation degree between any two types of monitoring information. A correlation matrix is ​​constructed, and the correlation relationships between the multi-dimensional monitoring information are established through the correlation matrix. The correlation degree is the mutual information value calculated by the mutual information coupling model. ; in, , For any two types of monitoring information.

5. The method for assessing the instability risk of strongly unloaded fractured rock slopes as described in claim 4, characterized in that, The mutual information value The expression is: ； in, for Take the first Values ​​and Take the first The joint probability of each value They are respectively Take the first individual values, Take the first The marginal probability of each value The number of sampling points for monitoring data within a specified time period.

6. The method for assessing the instability risk of strongly unloaded fractured rock slopes as described in claim 5, characterized in that, The method for determining the dominant perturbation factor includes the following: Based on the correlation matrix, a set of potential disturbance factors that are correlated with all the multi-dimensional monitoring information is selected. A disturbance factor contribution calculation model is constructed to calculate the contribution of each potential disturbance factor to the multi-dimensional monitoring information. Set the contribution threshold as When the contribution ≥ The contribution threshold If so, the current potential disturbance factor is determined as the dominant disturbance factor affecting slope stability within the current assessment unit.

7. The method for assessing the instability risk of strongly unloaded fractured rock slopes as described in claim 6, characterized in that, The real-time risk coefficient of the evaluation unit The calculation method includes the following: Obtain the rate of change of the determined dominant disturbance factor at the current moment, input the rate of change into the instability risk correlation function, and calculate the real-time risk coefficient through the instability risk correlation function. The real-time risk coefficient The calculation expression is: ； in, This represents the number of dominant disturbance factors within the current evaluation unit. For the first The weighting coefficients of the dominant disturbance factors, For the first The dominant disturbance factors at time rate of change, For the first Sensitivity index of the dominant disturbance factor.

8. The method for assessing the instability risk of a strongly unloaded fractured rock slope as described in claim 7, characterized in that, The risk coefficient difference between adjacent assessment units The calculation expression is: ； in, As an evaluation unit and The straight-line distance between the center points of the boundary. The characteristic length parameter of a strongly unloaded fractured rock slope.

9. The method for assessing the instability risk of a strongly unloaded fractured rock slope as described in claim 8, characterized in that, The risk transmission path is determined by constructing a directed risk transmission network, and the method for constructing the directed risk transmission network includes: Set risk transmission threshold ; Starting with all the high-risk assessment units as initial nodes, traverse all identified risk transmission channels, establish directed edges for each risk transmission channel according to the risk transmission direction, and calculate the risk transmission value for each non-high-risk unit. ; when When the current unit is incorporated into the risk transmission network and used as an intermediate node, the process is repeated iteratively to form a directed risk transmission network.

10. A risk assessment system for instability of fractured rock slopes under heavy unloading, characterized in that, The risk assessment method for instability of strongly unloaded fractured rock slopes according to any one of claims 1-9 is applied. The risk assessment system for instability of strongly unloaded fractured rock slopes includes a monitoring and acquisition unit, a dominant factor identification unit, a risk transmission calculation unit, and an assessment result generation unit. The monitoring and acquisition unit is used to collect multi-dimensional monitoring information data of the strongly unloaded fractured rock slope and spatial attribution information data of the on-site monitoring points, and transmit them synchronously to the dominant factor identification unit. The dominant factor identification unit is used to receive data transmitted by the monitoring and acquisition unit, determine the dominant disturbance factor and standardize the multi-dimensional monitoring information data, and transmit the dominant disturbance factor information data and the standardized multi-dimensional monitoring information data to the risk transmission calculation unit. The risk transmission calculation unit is used to receive data transmitted by the dominant factor identification unit and calculate the real-time risk coefficient. And determine the risk transmission channel, and transfer the real-time risk coefficient. The risk transmission channel judgment result is transmitted to the assessment result generation unit; the risk transmission channel judgment result includes risk transmission channel and transmission direction information; The evaluation result generation unit is used to receive the real-time risk coefficient transmitted by the risk transfer calculation unit. Based on the risk transmission channel assessment results, a risk assessment report on the instability of a strongly unloaded fractured rock slope is generated. The risk assessment report includes the location of high-risk units, risk transmission paths, warning levels, and quantitative data.

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