A landslide body instability grade determination method based on pore water pressure

Abstract

The application discloses a landslide body instability grade determination method based on pore water pressure, belongs to the technical field of geological disaster prevention, and can solve the problems of low utilization rate of historical data in existing landslide analysis, difficulty in quantifying real-time early warning, and obvious difference in response characteristics of different regions in the landslide body. The method comprises the following steps: S1, dividing the landslide body of a reservoir into a first research area and a second research area, and constructing historical fluctuation response data; S2, determining a historical standard parameter table of the landslide body based on the historical fluctuation response data, and constructing target fluctuation response data; S3, determining a target standard parameter set of the landslide body according to the target fluctuation response data and the historical standard parameter table; and S4, calculating an overall mismatch index of the landslide body based on the target fluctuation response data and the target standard parameter set, and determining the instability grade of the landslide body according to the overall mismatch index. The application is used for landslide body instability determination.

Description

Technical Field

[0001] This invention relates to a method for determining the instability level of landslides based on pore water pressure, belonging to the field of geological disaster prevention and control technology. Background Technology

[0002] Landslides, as a common geological hazard, pose a significant threat to the safe operation of reservoirs and their surrounding areas. The impoundment and discharge processes of reservoirs significantly affect the pore water pressure distribution and overall stability of landslide bodies on reservoir banks, especially in mountainous areas with high dams or steep slopes. Traditional landslide monitoring methods mainly rely on on-site pore pressure gauges, inclinometers, and surface displacement observations, using empirical thresholds to determine the presence of abnormal activity within the landslide body. However, these methods have significant limitations: first, it is difficult to quantify the overall risk of the landslide body, and single-point monitoring easily overlooks differences in internal structure; second, there is a lack of unified standard indicators, making direct comparison of responses between different events difficult, and historical data is hard to translate into real-time judgment criteria; third, landslide responses have hysteresis effects and nonlinear characteristics, especially during periods of rapid water level changes, where single-point observations or average values ​​cannot reflect the true changes in key risk areas.

[0003] In recent years, domestic and international research has begun to focus on landslide analysis methods based on changes in pore water pressure and hydrodynamic effects, studying landslide response patterns through numerical simulations or physical experiments. However, many challenges remain in practical engineering: low utilization of historical data, difficulty in quantifying real-time early warning, and significant differences in response characteristics among different regions within the landslide body. Summary of the Invention

[0004] This invention provides a method for determining the instability level of landslides based on pore water pressure, which can solve the problems of low utilization of historical data, difficulty in quantifying real-time early warning, and significant differences in response characteristics between different regions within the landslide body in existing landslide analysis.

[0005] This invention provides a method for determining the instability level of a landslide based on pore water pressure, the method comprising: S1. Divide the landslide body of the reservoir into a first study area and a second study area, and construct historical fluctuation response data based on the historical pore water pressure response data of the first study area and the second study area and the historical reservoir water level change data of the reservoir; wherein, the safety factor of the first study area is less than the safety factor of the second study area. S2. Based on the historical fluctuation response data, determine the historical standard parameter table of the landslide body, and construct the target fluctuation response data according to the target pore water pressure response data of the first study area and the second study area and the target reservoir water level change data of the reservoir. S3. Determine the target standard parameter set of the landslide body based on the target fluctuation response data and the historical standard parameter table; S4. Based on the target fluctuation response data and the target standard parameter set, calculate the overall mismatch index of the landslide body, and determine the instability level of the landslide body according to the overall mismatch index.

[0006] Optionally, the step S2, which determines the historical standard parameter table of the landslide body based on the historical fluctuation response data, specifically includes: Based on the historical reservoir water level change data in the historical fluctuation response data, the historical reservoir water level change events are divided into water release events and water storage events; Based on the historical pore water pressure response data in the historical fluctuation response data, determine the water discharge event response parameter table and the water storage event response parameter table respectively; Based on the water discharge event response parameter table and the water storage event response parameter table, the historical standard parameter table of the landslide body is determined.

[0007] Optionally, based on the historical pore water pressure response data in the historical fluctuation response data, a discharge event response parameter table and a water storage event response parameter table are determined respectively, specifically including: Based on the historical pore water pressure response data in the historical fluctuation response data, determine the first response parameter table for the first study area and the second response parameter table for the second study area in response to the water leakage event, and determine the water leakage event response parameter table based on the first response parameter table and the second response parameter table. Based on the historical pore water pressure response data in the historical fluctuation response data, the third response parameter table for the first study area and the fourth response parameter table for the second study area in response to the water storage event are determined respectively, and the water storage event response parameter table is determined based on the third response parameter table and the fourth response parameter table.

[0008] Optionally, based on the historical pore water pressure response data in the historical fluctuation response data, a first response parameter table for the first study area and a second response parameter table for the second study area to the discharge event are determined, specifically including: The water leakage event is divided into multiple water leakage fluctuation stages; The first standard response slope of the first study area in each of the drainage fluctuation stages is calculated based on the historical pore water pressure response data in the historical fluctuation response data, and all the first standard response slopes are summarized to obtain the first response parameter table of the first study area for the drainage event. The second standard response slope of the second study area in each of the drainage fluctuation stages is calculated based on the historical pore water pressure response data in the historical fluctuation response data, and all the second standard response slopes are summarized to obtain the second response parameter table of the second study area for the drainage event.

[0009] Optionally, based on the historical pore water pressure response data in the historical fluctuation response data, a third response parameter table for the first study area and a fourth response parameter table for the second study area to the water storage event are determined, specifically including: The water storage event is divided into multiple water storage fluctuation stages; The third standard response slope of the first study area in each of the water storage fluctuation stages is calculated based on the historical pore water pressure response data in the historical fluctuation response data, and all the third standard response slopes are summarized to obtain the third response parameter table of the first study area for the water storage event. The fourth standard response slope of the second study area in each of the water storage fluctuation stages is calculated based on the historical pore water pressure response data in the historical fluctuation response data, and all the fourth standard response slopes are summarized to obtain the fourth response parameter table of the second study area for the water storage event.

[0010] Optionally, S3 specifically includes: Based on the target reservoir water level change data in the target fluctuation response data, determine the type of target reservoir water level change event; When the target reservoir water level change event is a discharge event, the discharge event response parameter table is selected as the target standard parameter set for the landslide body; When the target reservoir water level change event is the water storage event, the water storage event response parameter table is selected as the target standard parameter set for the landslide body.

[0011] Optionally, in step S4, the overall mismatch index of the landslide body is calculated based on the target fluctuation response data and the target standard parameter set, specifically including: The target time corresponding to the target reservoir water level change event is divided into multiple time steps, and the mismatch sub-indices of the landslide body are calculated at each time step based on the target fluctuation response data and the target standard parameter set. The overall mismatch index of the landslide body is obtained by averaging the mismatch sub-indices corresponding to all time steps.

[0012] Optionally, based on the target fluctuation response data and the target standard parameter set, the mismatch sub-index corresponding to the landslide body at each time step is calculated, specifically including: Based on the target pore water pressure response data in the target fluctuation response data, the first pore pressure change slope of the first study area at each time step and the second pore pressure change slope of the second study area at each time step are calculated respectively. Calculate the ratio of the first pore pressure change slope to the standard response slope of the corresponding time step in the target standard parameter set to obtain the first slope response ratio, and calculate the ratio of the second pore pressure change slope to the standard response slope of the corresponding time step in the target standard parameter set to obtain the second slope response ratio. Spatially weight the ratio of the first slope response and the ratio of the second slope response corresponding to the same time step to obtain the mismatch index of the landslide body at that time step.

[0013] Optionally, determining the instability level of the landslide body based on the overall mismatch index in step S4 specifically includes: Based on the overall mismatch index and in combination with multiple preset thresholds, the mismatch level of the landslide body is determined; The instability level of the landslide body is determined based on the mismatch level.

[0014] Optionally, before determining the instability level of the landslide body based on the mismatch level, the method further includes: The extreme values ​​of the mismatch sub-indices of the landslide body at all time steps were statistically analyzed. The mismatch level is verified by using the extreme value information to obtain the verified mismatch level.

[0015] The beneficial effects that this invention can produce include: This invention provides a method for determining the instability level of landslides based on pore water pressure. By constructing a historical standard parameter table, it uses the correspondence between reservoir water level changes and pore pressure response under typical historical conditions as a benchmark. Then, it compares the real-time response of the target event with the historical standard response to calculate the overall mismatch index of the landslide, thereby quantifying the landslide's response to reservoir water level changes into comparable and gradeable numerical results. The initial design intent of this invention is to utilize the coupling relationship between the internal pore pressure response of the landslide and external reservoir water level fluctuations. By analyzing whether the two maintain historical normal response patterns, abnormal states can be identified. A high degree of matching indicates that the landslide is in a stable state, while a significant mismatch reflects an abnormality in the internal hydraulic response mechanism of the landslide, increasing the risk of instability. Based on this, this invention achieves a near real-time quantitative assessment of landslide instability risk, fully utilizing historical monitoring experience while also considering real-time monitoring information. This allows for a more accurate reflection of the overall stability of the landslide, improving the scientific rigor and reliability of landslide disaster early warning and reservoir safety operation management. Attached Figure Description

[0016] Figure 1 A flowchart of a landslide instability level determination method based on pore water pressure provided in an embodiment of the present invention; Figure 2 This is a structural block diagram of a landslide instability level determination system based on pore water pressure provided in an embodiment of the present invention. Detailed Implementation

[0017] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0018] This invention provides a method for determining the instability level of a landslide based on pore water pressure, such as... Figure 1 As shown, the method includes: S1. The landslide body of the reservoir is divided into the first study area and the second study area, and historical fluctuation response data are constructed based on the historical pore water pressure response data of the first study area and the second study area and the historical reservoir water level change data of the reservoir; wherein, the safety factor of the first study area is smaller than that of the second study area.

[0019] Specifically, it includes: (1) The landslide body is divided into a first study area and a second study area; wherein, the first study area indicates the structurally fragile area in the landslide body, and the second study area indicates the structurally stable area in the landslide body.

[0020] The specific implementation includes: First, based on the geological structural characteristics and stability differences of the landslide body, the landslide body is divided into the first study area and the second study area. The first study area is used to characterize the relatively fragile areas of the landslide body that are sensitive to changes in reservoir water level, while the second study area is used to characterize the relatively stable areas of the landslide body that are relatively slow to respond to changes in reservoir water level.

[0021] After the zoning was completed, pore water pressure monitoring points were set up in the first and second study areas respectively to obtain pore water pressure response data for the corresponding areas. Specifically, 3-5 pore pressure monitoring points were set up in the first study area to reflect the response characteristics of vulnerable areas; and 5-8 pore pressure monitoring points were set up in the second study area to reflect the basic response characteristics of stable areas.

[0022] The aforementioned monitoring points were pre-deployed within the landslide body and continuously collected pore water pressure response data during reservoir water level changes, forming the basis for subsequent historical fluctuation response data and target fluctuation response data.

[0023] This step involves dividing the landslide body into a structurally vulnerable first study area and a structurally stable second study area, and deploying pore water pressure monitoring points in each area. This allows for the acquisition of high-quality, representative pore pressure data tailored to the response characteristics of different regions. This not only provides a reliable foundation for subsequent statistical analysis of historical fluctuation response data but also fully reflects the internal structural differences and response hysteresis characteristics of the landslide body. Consequently, it provides an accurate basis for determining landslide instability and calculating overall mismatch indicators, improving the scientific rigor and reliability of landslide risk assessment.

[0024] (2) Collect historical fluctuation response data of the first and second study areas; wherein, the historical fluctuation response data includes historical reservoir water level change data and corresponding historical pore water pressure response data.

[0025] The specific implementation includes: First, based on the reservoir scheduling record table, several typical water release events and typical water storage events with complete operating conditions and monitoring data are selected as historical analysis samples. Ideally, three adjacent water release events and three water storage events are selected to maintain a balanced configuration of the number of water release events and water storage events in the historical samples.

[0026] Secondly, the selected historical reservoir water level change events all belong to the typical water release and water storage processes in the normal operation of the reservoir. Their change processes are directly controlled by the operation and scheduling of the reservoir and have uniform engineering boundary conditions. Therefore, they can be used as the historical basic data source for constructing the standard parameter table of the landslide body.

[0027] Finally, the reservoir water level change data corresponding to the selected historical events are time-correlated with the pore water pressure response data of the first and second study areas to form historical fluctuation response data, which is used for the construction of subsequent standard parameter tables.

[0028] This step selects typical historical discharge and impoundment events based on the reservoir scheduling record table and constructs corresponding historical fluctuation response data, avoiding a complex event identification process and improving data acquisition efficiency. Furthermore, since multiple discharge and impoundment events in the reservoir all fall under the same repetitive operating conditions within the same scheduling mechanism, their reservoir water level changes exhibit high consistency and repeatability. This ensures that the constructed historical fluctuation response data has good engineering representativeness and stability, providing a reliable data foundation for subsequent standard parameter extraction and landslide instability assessment.

[0029] S2. Based on historical fluctuation response data, determine the historical standard parameter table of the landslide body, and construct the target fluctuation response data according to the target pore water pressure response data of the first and second study areas and the target reservoir water level change data of the reservoir.

[0030] Based on historical fluctuation response data, S2 defines a table of historical standard parameters for the landslide body, which specifically includes: (1) Based on the historical reservoir water level change data in the historical fluctuation response data, the historical reservoir water level change events are divided into water release events and water storage events.

[0031] (2) Determine the response parameter table for the water discharge event and the response parameter table for the water storage event based on the historical pore water pressure response data in the historical fluctuation response data.

[0032] Specifically, it includes: 1) Based on the historical pore water pressure response data in the historical fluctuation response data, determine the first response parameter table for the first study area and the second response parameter table for the second study area to the water discharge event, and determine the water discharge event response parameter table based on the first response parameter table and the second response parameter table.

[0033] Specifically: First, the discharge event is divided into multiple discharge fluctuation stages. Then, based on the historical pore water pressure response data in the historical fluctuation response data, the first standard response slope of the first study area in each discharge fluctuation stage is calculated, and all first standard response slopes are summarized to obtain the first response parameter table of the first study area for the discharge event. Simultaneously, based on the historical pore water pressure response data in the historical fluctuation response data, the second standard response slope of the second study area in each discharge fluctuation stage is calculated, and all second standard response slopes are summarized to obtain the second response parameter table of the second study area for the discharge event. Finally, the first response parameter table and the second response parameter table are combined to obtain the discharge event response parameter table.

[0034] 2) Based on the historical pore water pressure response data in the historical fluctuation response data, determine the third response parameter table for the first study area and the fourth response parameter table for the second study area in response to the water storage event, and determine the water storage event response parameter table based on the third response parameter table and the fourth response parameter table.

[0035] Specifically: First, the water storage event is divided into multiple water storage fluctuation stages. Then, based on the historical pore water pressure response data in the historical fluctuation response data, the third standard response slope of the first study area in each water storage fluctuation stage is calculated, and all third standard response slopes are summarized to obtain the third response parameter table of the first study area for the water storage event. Simultaneously, based on the historical pore water pressure response data in the historical fluctuation response data, the fourth standard response slope of the second study area in each water storage fluctuation stage is calculated, and all fourth standard response slopes are summarized to obtain the fourth response parameter table of the second study area for the water storage event. Finally, the third and fourth response parameter tables are combined to obtain the water storage event response parameter table.

[0036] (3) Determine the historical standard parameter table of the landslide body based on the water discharge event response parameter table and the water storage event response parameter table.

[0037] The specific implementation includes: Based on the collected historical reservoir water level change data, three historical water release events and three historical water storage events were identified.

[0038] The following example illustrates the process of obtaining the response parameter table for a water leakage event: Assuming a single water discharge event lasts for 12 hours, data is sampled every 15 minutes, with four samples per hour. Preferably, the water discharge event can be divided into three water discharge fluctuation phases, such as: rapid water discharge phase: 1-4 hours, stable water discharge phase: 5-8 hours, and slow water discharge phase: 9-12 hours.

[0039] For each sampling time Pore ​​water pressure zone values ​​in the first and second study areas Measured pore water pressure response data from multiple monitoring points within each study area On average: ; in, These represent the first and second research areas, respectively. This represents the number of measurement points in the corresponding study area.

[0040] This allows us to obtain the pore water pressure values ​​for the first and second study areas at various sampling times, providing a basis for subsequent slope calculations.

[0041] For each stage ( Corresponding to the rapid discharge period, the steady discharge period, and the slow discharge period, four consecutive sampling hours (16 sampling times) were selected during this stage. The corresponding pore water pressure zone value Perform linear fitting.

[0042] The linear fitting formula is as follows: ; in, The 16 sampling times in this phase; The slope of the stage; This is the intercept.

[0043] Calculate the stage slope using the least squares method. The calculation formula is as follows: ; Because three adjacent historical discharge events occurred at the same stage slope The differences are not significant, and the trends are consistent. Therefore, for the same stage of the three water release events... The average slope is taken as the discharge fluctuation stage. The first standard response slope is calculated using the following formula: ; in, For the first During the period of water discharge fluctuation in the study area The first standard response slope.

[0044] The above process yields the response parameter table for water release events. The handling method for water storage events is the same as that for water release events, including stage division, zone value calculation, slope fitting, and mean statistics. The water storage event response parameter table is obtained after the process is completed.

[0045] The standard response slopes of the first and second study areas during the water discharge and water storage phases were summarized to form a complete historical standard parameter table; the historical standard parameter table is shown in Table 1.

[0046] Table 1 Historical Standard Parameter Table

[0047] In summary, this step, by further dividing historical discharge and storage events into multiple fluctuation stages and statistically analyzing the standard response slopes corresponding to each fluctuation stage in both the first and second study areas, establishes a standard correspondence between reservoir water level changes and pore water pressure responses. Since the standard response slopes are determined from the statistical results of multiple typical historical events, the impact of accidental factors in a single event can be effectively reduced, improving the stability and representativeness of the standard parameters. Furthermore, by constructing a historical standard parameter table in stages, the pore pressure response patterns under different reservoir water level change stages can be characterized more precisely, providing a reliable basis for subsequent mismatch analysis of target events and determination of landslide instability levels.

[0048] Next, target fluctuation response data were collected for the first and second study areas; the target fluctuation response data included target reservoir water level change data and corresponding target pore water pressure response data.

[0049] The specific implementation includes: First, the start and end times of the target reservoir water level change event are determined based on the reservoir scheduling record table. The target reservoir water level change event is the water level change process currently to be determined. Based on the start and end times, the reservoir water level monitoring data for the corresponding time period is extracted as the target reservoir water level change data.

[0050] Secondly, based on the time interval corresponding to the target reservoir water level change event, monitoring data from each pore water pressure monitoring point in the first and second study areas are extracted simultaneously, thus forming target pore water pressure response data corresponding to the target reservoir water level change data. Finally, the target reservoir water level change data and the corresponding target pore water pressure response data are correlated over time to obtain the target fluctuation response data.

[0051] This step, by simultaneously acquiring target reservoir water level change data and target pore water pressure response data within the corresponding time period based on the start and end times of the target reservoir water level change event, establishes a correlation between the reservoir water level change process and the pore pressure response process. This provides an accurate data foundation for subsequent selection of target standard parameter sets and calculation of the overall mismatch index of the landslide body. Furthermore, using a unified time interval for data extraction ensures temporal consistency between different data sources, improving the reliability and accuracy of subsequent instability determination results.

[0052] S3. Determine the target standard parameter set of the landslide body based on the target fluctuation response data and historical standard parameter table.

[0053] Specifically, it includes: Based on the target reservoir water level change data in the target fluctuation response data, determine the type of target reservoir water level change event; When the target reservoir water level change event is a discharge event, the discharge event response parameter table is selected as the target standard parameter set for the landslide body. When the target reservoir water level change event is a water storage event, the water storage event response parameter table is selected as the target standard parameter set for the landslide body.

[0054] The specific implementation includes: Based on the target reservoir water level change data, analyze the trend of water level change within the target time period; when the reservoir water level shows a continuous downward trend, the target reservoir water level change event is determined to be a water release event, and when the reservoir water level shows a continuous upward trend, the target reservoir water level change event is determined to be a water storage event.

[0055] Based on the target reservoir water level change event, the corresponding target standard parameter set is selected directly from the historical standard parameter table.

[0056] This step directly determines the type of target reservoir water level change event based on the target reservoir water level change data, and selects the corresponding release event or water storage event response parameter set from the historical standard parameter table. This achieves rapid matching between the target event and historical standard parameters, avoids complex secondary analysis processes, and improves the accuracy of standard parameter selection and processing efficiency.

[0057] S4. Based on the target fluctuation response data and the target standard parameter set, calculate the overall mismatch index of the landslide body, and determine the instability level of the landslide body according to the overall mismatch index.

[0058] Specifically, it includes: (1) Divide the target time corresponding to the target reservoir water level change event into multiple time steps, and calculate the mismatch sub-indices of the landslide body at each time step based on the target fluctuation response data and the target standard parameter set.

[0059] Specifically: 1) Divide the target time corresponding to the target reservoir water level change event into multiple time steps; 2) Based on the target pore water pressure response data in the target fluctuation response data, calculate the first pore pressure change slope of the first study area at each time step and the second pore pressure change slope of the second study area at each time step. 3) Calculate the ratio of the first pore pressure change slope to the standard response slope of the corresponding time step in the target standard parameter set to obtain the first slope response ratio, and calculate the ratio of the second pore pressure change slope to the standard response slope of the corresponding time step in the target standard parameter set to obtain the second slope response ratio. 4) Spatially weight the ratio of the first slope response and the ratio of the second slope response at the same time step to obtain the mismatch index of the landslide body at the time step.

[0060] (2) The mismatch sub-indices corresponding to all time steps are averaged over time to obtain the overall mismatch index of the landslide body.

[0061] (3) Determine the instability level of the landslide body based on the overall mismatch index.

[0062] The specific implementation includes: First, the target time corresponding to the target reservoir water level change event is divided into 12 time steps ( Each time step is 1 hour long; each time step corresponds to 4 sampling times, such as the first time step containing... .

[0063] The pore pressure values ​​of the first and second study areas at each sampling time were calculated using the aforementioned method, and the values ​​are as follows: , ; in, ; This represents the pore pressure value of the first study area at each sampling time. This represents the pore pressure value of the second study area at each sampling time.

[0064] Next, the slope corresponding to each time step is calculated: within each time step, the slope of pore pressure change is calculated using the pore pressure values ​​at four sampling times. The slopes of each time step are calculated for the first and second study areas respectively, to quantify the response speed and sensitivity of different regions to changes in reservoir water level.

[0065] The slope of the first pore pressure change in the first study area (12 time steps): The slope of the first pore pressure change corresponding to the first time step is calculated using the following formula: ; in, The slope of the first pore pressure change corresponding to the first time step; Based on the above formula, the result can be obtained by calculating sequentially. , ; The slope of the second pore pressure change in the second study area (12 time steps): The slope of the second pore pressure change corresponding to the first time step is calculated using the following formula: ; in, The slope of the second pore pressure change corresponding to the first time step; Based on the above formula, the result can be obtained by calculating sequentially. , .

[0066] Next, the actual pore pressure change slope at each time step is compared with the standard response slope of the corresponding stage; this can reflect the degree of deviation between the current response and the typical historical response, thus providing a quantifiable basis for the mismatch index.

[0067] The first slope response ratio (over 12 time steps) of the first study region is calculated using the following formula: ; in, The ratio of the first slope response for all time steps. ; The standard response slope of the first study area corresponding to the target standard parameter set, such as hour, ; The second slope response ratio (over 12 time steps) for the second study region is calculated using the following formula: ; in, The ratio of the second slope response for all time steps. ; For the standard response slope of the second study area corresponding to the target standard parameter set, such as hour, ; Next, the slope ratios of the two study areas at the same time step are weighted according to a preset spatial weight to obtain the mismatch index of the landslide body at each time step; this can simultaneously consider the response differences between structurally vulnerable areas and stable areas, highlighting the impact of key areas. Calculate the mismatch index of the landslide body for each time step; the calculation formula is as follows: , ; in, The mismatch index of the landslide body for all time steps. ; , These are the preset spatial weights corresponding to the first and second study areas, respectively. Preferably, ; When selecting weights, the weight of the first study area can be slightly larger, and the weight of the second study area can be slightly smaller (in order to focus on the lag area, but to ensure the integrity of the response).

[0068] Finally, the mismatch sub-indices of all time steps are averaged over time to obtain the overall mismatch index of the landslide body. This index can comprehensively reflect the stability state of the landslide body during the entire target reservoir water level event, providing a quantitative basis for subsequent instability level determination. The calculation formula for the overall mismatch index of the landslide body is as follows: ; in, This is an indicator of the overall mismatch of the landslide body.

[0069] This step divides the target reservoir water level change event into multiple time steps, calculates the pore pressure change slopes of the first and second study areas within each time step, and then performs a ratio analysis with the historical standard response slope. Combined with spatial weighting and time averaging, an overall mismatch index for the landslide body is obtained, achieving a temporal and quantitative characterization of the landslide response process. This method can simultaneously consider the spatial differences between different study areas and the temporal evolution characteristics of the reservoir water level change process, reducing the random influence of a single moment or region, and improving the stability and reliability of the mismatch index in reflecting the overall landslide state. This provides a more accurate quantitative basis for subsequent instability level determination.

[0070] S4 determines the instability level of the landslide body based on the overall mismatch index, specifically including: Based on the overall mismatch index and combined with multiple preset thresholds, the mismatch level of the landslide body is determined; The instability level of the landslide body is determined based on the mismatch level.

[0071] The correspondence between the mismatch level and the instability level includes: When the mismatch level is the first level, the landslide body is determined to be in a stable state; When the mismatch level is level two, the landslide body is determined to be in a low-risk instability state; When the mismatch level is level three, the landslide body is determined to be in a medium-risk unstable state; When the mismatch level is level four, the landslide body is determined to be in a high-risk instability state.

[0072] Furthermore, before determining the instability level of the landslide body based on the mismatch level, the method further includes: Statistical analysis of extreme values ​​of mismatch sub-indices of landslide bodies across all time steps; The mismatch level is verified by using extreme value information to obtain the verified mismatch level.

[0073] The specific implementation includes: Multiple preset thresholds are preferably controlled within six preset thresholds. The six preset thresholds and the overall mismatch index of the landslide body are used to preliminarily determine the mismatch level; the preferred mismatch level determination table is shown in Table 2.

[0074] Table 2 Mismatch Level Determination Table

[0075] By comparing the overall mismatch index of the landslide body with Table 2, a preliminary mismatch level can be obtained.

[0076] Next, statistical analysis was performed on the landslide mismatch sub-indices corresponding to each time step to obtain their extreme values: ; in, The maximum value of the landslide body mismatch sub-index sequence is used to reflect the most unfavorable response state of the landslide body during the entire reservoir water level change process.

[0077] Next, the overall mismatch index of the landslide body will be determined. The corresponding mismatch level and extreme value Compare the corresponding mismatch levels: like The corresponding mismatch level is higher than The corresponding level is then used to verify the initial mismatch level, and the verified mismatch level is the final mismatch level, which is then adjusted upwards. Corresponding level; like The corresponding mismatch level is lower than The corresponding level or the If the corresponding levels are consistent, the mismatch level after verification remains the original mismatch level.

[0078] This mechanism is used to avoid the "smoothing masking effect" of local extreme responses during time averaging, thereby improving the ability to identify local mutation risks.

[0079] Finally, the instability level of the landslide body was determined based on the correspondence between the mismatch level and the instability level. The correspondence is shown in Table 3.

[0080] Table 3 Correspondence Table

[0081] This step involves mapping the overall mismatch index of the landslide body to a preset mismatch level range to achieve a graded determination of the landslide's stability state. Simultaneously, an auxiliary verification mechanism is introduced using the extreme values ​​of time-step mismatch sub-indicators to correct the overall average result. This prevents significant abnormal responses in local time periods from being masked by the time averaging process, thereby improving the sensitivity and reliability of the instability level determination. Ultimately, this more accurately reflects the actual risk state of the landslide body under target reservoir water level change events, providing a reliable basis for landslide disaster early warning and reservoir safety operation management.

[0082] This invention utilizes the matching relationship between external hydrodynamic forces and internal pore water pressure response to characterize the stability state of a landslide. Existing technologies typically rely on single monitoring parameters such as pore pressure and displacement values, making it difficult to transform real-time monitoring data into a unified risk quantification index. This invention, however, constructs a historical standard parameter table, using the correspondence between reservoir water level changes and pore pressure response under typical historical conditions as a benchmark. It then compares the real-time response of the target event with the historical standard response to calculate the overall mismatch index of the landslide, thereby quantifying the landslide's response to reservoir water level changes into comparable and gradable numerical results. The initial design intent of this invention is to utilize the coupling relationship between the internal pore pressure response of the landslide and external reservoir water level fluctuations. By analyzing whether the two maintain historical normal response patterns, abnormal states can be identified. A high degree of matching indicates that the landslide is in a stable state, while a significant mismatch reflects an abnormality in the internal hydraulic response mechanism of the landslide, increasing the risk of instability. Based on this, the present invention realizes a near real-time quantitative assessment of landslide instability risk, which makes full use of historical monitoring experience and takes into account real-time monitoring information, and can more accurately reflect the overall stability of the landslide, thereby improving the scientificity and reliability of landslide disaster early warning and reservoir safe operation management.

[0083] Another embodiment of the present invention provides a landslide instability level determination system based on pore water pressure, such as... Figure 2 As shown, the system includes: The regional division unit is used to divide the landslide body of the reservoir into a first study area and a second study area; wherein the safety factor of the first study area is smaller than that of the second study area. The historical data acquisition unit, connected to the regional division unit, is used to construct historical fluctuation response data based on the historical pore water pressure response data of the first and second study areas and the historical reservoir water level change data of the reservoir. The historical standard parameter statistics unit is connected to the historical data acquisition unit and is used to determine the historical standard parameter table of the landslide body based on historical fluctuation response data. The target data acquisition unit, connected to the regional division unit, is used to construct target fluctuation response data based on the target pore water pressure response data of the first and second study areas and the target reservoir water level change data of the reservoir. The target standard parameter selection unit is connected to the historical standard parameter statistics unit and the target data acquisition unit. It is used to determine the target standard parameter set of the landslide body based on the target fluctuation response data and the historical standard parameter table. The mismatch index calculation unit is connected to the target data acquisition unit and the target standard parameter selection unit. It is used to calculate the overall mismatch index of the landslide body based on the target fluctuation response data and the target standard parameter set. The instability level determination unit, connected to the mismatch index calculation unit, is used to determine the instability level of the landslide body based on the overall mismatch index.

[0084] Specifically, the historical standard parameter statistical units include: The historical event classification module is used to classify historical reservoir water level change events into water release events and water storage events based on historical reservoir water level change data in historical fluctuation response data. The discharge parameter construction module, connected to the historical event classification module, is used to divide discharge events into multiple discharge fluctuation stages based on their changing characteristics. It calculates the first standard response slope for the first study area in each discharge fluctuation stage and summarizes these slopes to obtain a first response parameter table for the first study area in response to discharge events. It also calculates the second standard response slope for the second study area in each discharge fluctuation stage and summarizes these slopes to obtain a second response parameter table for the second study area in response to discharge events. Finally, it combines the first and second response parameter tables to obtain a discharge event response parameter table. The water storage parameter construction module, connected to the historical event classification module, is used to divide water storage events into multiple water storage fluctuation stages based on their changing characteristics; calculate the third standard response slope of the first study area in each water storage fluctuation stage, and summarize it to obtain the third response parameter table of the first study area for water storage events; calculate the fourth standard response slope of the second study area in each water storage fluctuation stage, and summarize it to obtain the fourth response parameter table of the second study area for water storage events; and summarize the third and fourth response parameter tables to obtain the water storage event response parameter table. The standard parameter generation module, connected to the discharge parameter construction module and the water storage parameter construction module, is used to summarize the discharge event response parameter table and the water storage event response parameter table to obtain the historical standard parameter table.

[0085] Specifically, the target standard parameter selection unit includes: The target event type determination module is used to determine the type of target reservoir water level change event based on the target reservoir water level change data; The target standard parameter selection module is connected to the target event type judgment module. When the target reservoir water level change event is a discharge event, it selects the discharge event response parameter table as the target standard parameter set; when the target reservoir water level change event is a water storage event, it selects the water storage event response parameter table as the target standard parameter set.

[0086] The landslide instability level determination system based on pore water pressure provided by this invention divides the landslide body into a first study area with weak structure and a second study area with relatively stable structure, thereby realizing the zonal analysis of the internal response characteristics of the landslide body and fully considering the differences in sensitivity and hysteresis of different regions to reservoir water level fluctuations. The various units are physically or logically connected to form a complete data flow and computation chain: the regional division unit provides zoning information; the historical data acquisition unit collects historical fluctuation response data based on pore water pressure measurement points and reservoir scheduling records deployed in each study area; the historical standard parameter statistics unit further classifies, divides, and calculates standard slopes for historical data to form a historical standard parameter table, providing a reliable benchmark for subsequent target event analysis; the target data acquisition unit acquires real-time changes in target reservoir water level and corresponding pore pressure response; the target standard parameter selection unit selects the corresponding parameter set from the historical standard parameter table according to the target event type, achieving seamless integration of historical and real-time data; the mismatch index calculation unit uses target data and target standard parameter set to calculate mismatch sub-indices of the landslide body at each time step and performs spatial weighting to obtain the overall mismatch index of the landslide body, providing a quantitative basis for determining the instability level; the instability level determination unit classifies the overall mismatch index based on preset thresholds and further enhances the robustness of the determination through extreme value verification, thereby clarifying the stable or unstable state of the landslide body. Through the collaborative work of the aforementioned units, the system can organically combine historical experience with real-time monitoring information to achieve near real-time quantitative assessment of landslide instability risk. This not only improves the sensitivity and accuracy of landslide response characteristics but also provides scientific and reliable technical support for reservoir operation management and landslide disaster early warning. At the same time, it reduces the burden of manual analysis and realizes an automated process from data collection to instability determination.

[0087] The above descriptions are merely a few embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any modifications or alterations made by those skilled in the art without departing from the scope of the technical solution of the present invention using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for determining the instability level of a landslide based on pore water pressure, characterized in that, The method includes: S1. Divide the landslide body of the reservoir into a first study area and a second study area, and construct historical fluctuation response data based on the historical pore water pressure response data of the first study area and the second study area and the historical reservoir water level change data of the reservoir; wherein, the safety factor of the first study area is less than the safety factor of the second study area. S2. Based on the historical fluctuation response data, determine the historical standard parameter table of the landslide body, and construct the target fluctuation response data according to the target pore water pressure response data of the first study area and the second study area and the target reservoir water level change data of the reservoir. S3. Determine the target standard parameter set of the landslide body based on the target fluctuation response data and the historical standard parameter table; S4. Based on the target fluctuation response data and the target standard parameter set, calculate the overall mismatch index of the landslide body, and determine the instability level of the landslide body according to the overall mismatch index.

2. The method according to claim 1, characterized in that, The step S2, which determines the historical standard parameter table of the landslide body based on the historical fluctuation response data, specifically includes: Based on the historical reservoir water level change data in the historical fluctuation response data, the historical reservoir water level change events are divided into water release events and water storage events; Based on the historical pore water pressure response data in the historical fluctuation response data, determine the water discharge event response parameter table and the water storage event response parameter table respectively; Based on the water discharge event response parameter table and the water storage event response parameter table, the historical standard parameter table of the landslide body is determined.

3. The method according to claim 2, characterized in that, Based on the historical pore water pressure response data in the historical fluctuation response data, the discharge event response parameter table and the water storage event response parameter table are determined respectively, specifically including: Based on the historical pore water pressure response data in the historical fluctuation response data, determine the first response parameter table for the first study area and the second response parameter table for the second study area in response to the water leakage event, and determine the water leakage event response parameter table based on the first response parameter table and the second response parameter table. Based on the historical pore water pressure response data in the historical fluctuation response data, the third response parameter table for the first study area and the fourth response parameter table for the second study area in response to the water storage event are determined respectively, and the water storage event response parameter table is determined based on the third response parameter table and the fourth response parameter table.

4. The method according to claim 3, characterized in that, Based on the historical pore water pressure response data in the historical fluctuation response data, a first response parameter table for the first study area and a second response parameter table for the second study area to the discharge event are determined, specifically including: The water leakage event is divided into multiple water leakage fluctuation stages; The first standard response slope of the first study area in each of the drainage fluctuation stages is calculated based on the historical pore water pressure response data in the historical fluctuation response data, and all the first standard response slopes are summarized to obtain the first response parameter table of the first study area for the drainage event. The second standard response slope of the second study area in each of the drainage fluctuation stages is calculated based on the historical pore water pressure response data in the historical fluctuation response data, and all the second standard response slopes are summarized to obtain the second response parameter table of the second study area for the drainage event.

5. The method according to claim 3, characterized in that, Based on the historical pore water pressure response data in the historical fluctuation response data, a third response parameter table for the first study area and a fourth response parameter table for the second study area to the water storage event are determined, specifically including: The water storage event is divided into multiple water storage fluctuation stages; The third standard response slope of the first study area in each stage of water storage fluctuation is calculated based on the historical pore water pressure response data in the historical fluctuation response data, and all the third standard response slopes are summarized to obtain the third response parameter table of the first study area for the water storage event. The fourth standard response slope of the second study area in each of the water storage fluctuation stages is calculated based on the historical pore water pressure response data in the historical fluctuation response data, and all the fourth standard response slopes are summarized to obtain the fourth response parameter table of the second study area for the water storage event.

6. The method according to claim 2, characterized in that, S3 specifically includes: Based on the target reservoir water level change data in the target fluctuation response data, determine the type of target reservoir water level change event; When the target reservoir water level change event is a discharge event, the discharge event response parameter table is selected as the target standard parameter set for the landslide body; When the target reservoir water level change event is the water storage event, the water storage event response parameter table is selected as the target standard parameter set for the landslide body.

7. The method according to claim 6, characterized in that, The step S4, which calculates the overall mismatch index of the landslide body based on the target fluctuation response data and the target standard parameter set, specifically includes: The target time corresponding to the target reservoir water level change event is divided into multiple time steps, and the mismatch sub-index of the landslide body in each time step is calculated based on the target fluctuation response data and the target standard parameter set. The overall mismatch index of the landslide body is obtained by averaging the mismatch sub-indices corresponding to all time steps.

8. The method according to claim 7, characterized in that, Based on the target fluctuation response data and the target standard parameter set, the mismatch sub-indices of the landslide body at each time step are calculated, specifically including: Based on the target pore water pressure response data in the target fluctuation response data, the first pore pressure change slope of the first study area at each time step and the second pore pressure change slope of the second study area at each time step are calculated respectively. Calculate the ratio of the first pore pressure change slope to the standard response slope of the corresponding time step in the target standard parameter set to obtain the first slope response ratio, and calculate the ratio of the second pore pressure change slope to the standard response slope of the corresponding time step in the target standard parameter set to obtain the second slope response ratio. Spatially weight the ratio of the first slope response and the ratio of the second slope response corresponding to the same time step to obtain the mismatch index of the landslide body at that time step.

9. The method according to claim 1, characterized in that, The step S4, determining the instability level of the landslide body based on the overall mismatch index, specifically includes: Based on the overall mismatch index and in combination with multiple preset thresholds, the mismatch level of the landslide body is determined; The instability level of the landslide body is determined based on the mismatch level.

10. The method according to claim 9, characterized in that, Before determining the instability level of the landslide body based on the mismatch level, the method further includes: The extreme values ​​of the mismatch sub-indices of the landslide body at all time steps were statistically analyzed. The mismatch level is verified by using the extreme value information to obtain the verified mismatch level.

Images