Anti-seepage control system for earth rock cofferdam

Abstract

The invention relates to the technical field of water conservancy projects, in particular to an anti-seepage control system for an earth rock cofferdam. The method comprises the following steps: periodically acquiring external hydro meteorological data and internal structure response data of a cofferdam through a sensor group based on a monitoring unit; establishing a multi-field coupling model based on a finite element method through a model building unit, and dynamically coupling a wave load, a tidal water level and an osmotic pressure field; the minimum cofferdam crest elevation is determined by comparing the difference between the minimum safety coefficient and a preset safety coefficient on the basis of a decision-making unit; and based on the analysis unit, inputting the minimum cofferdam crest elevation into the multi-field coupling model to obtain the maximum value of the hydraulic gradient of the escape point of the downstream slope within a third preset time period, determining an anti-seepage state based on the maximum value, and adjusting related parameters based on the anti-seepage state. The seepage risk of the cofferdam is monitored, predicted and actively controlled in real time, so that the seepage rate of the earth rock cofferdam is reduced.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, and in particular to a seepage prevention control system for earth-rock cofferdams. Background Technology

[0002] In marine environments, cofferdams must withstand extreme loads such as typhoons, spring tides, and storm surges. Existing design methods mostly employ static load design, which cannot accurately simulate the complex interactions between wave loads, dynamic water level changes, and the internal seepage field of the cofferdam under the coupled effects of typhoons, spring tides, and storm surges. This leads to excessive safety margins in the design, resulting in economic waste, or insufficient estimation under extreme conditions, posing risks of overtopping and cofferdam failure.

[0003] Chinese Patent Publication No. CN114969933A discloses a method for constructing a parametric model of an earth-rock cofferdam, an electronic device, and a storage medium. The method includes: constructing the topographic surface of the earth-rock cofferdam filling area; determining the location of the cofferdam's centerline and drawing the centerline at that location; determining the design elevation of the cofferdam crest; modifying the characteristics and style of the longitudinal section diagram according to the drawing standards, customizing the required longitudinal section diagram style set, and then drawing the longitudinal section diagram and drawing the cofferdam crest design elevation control line on the longitudinal section diagram; constructing a parametric cross-section of the cofferdam; creating a cross-section assembly, loading the parametric cross-section of the cofferdam, and inserting it into the cross-section assembly; when the geometric parameters of the parametric cross-section of the cofferdam meet the requirements, selecting the already drawn or constructed cofferdam centerline, the cofferdam crest design elevation control line, and the cofferdam parametric cross-section on the cofferdam creation interface to generate a parametric model of the earth-rock cofferdam.

[0004] It is evident that existing technologies suffer from the following problems: the lack of systematic theoretical support for load calculation under extreme working conditions and the optimization of cofferdam crest elevation during construction leads to high leakage rates. Summary of the Invention

[0005] Therefore, the present invention provides a seepage prevention control system for earth-rock cofferdams to overcome the problem in the prior art that there is a lack of systematic theoretical support for load calculation under extreme working conditions and construction optimization of cofferdam top elevation, resulting in high leakage rate.

[0006] To achieve the above objectives, the present invention provides a seepage prevention control system for earth-rock cofferdams, comprising: The monitoring unit is used to periodically monitor the data set based on the sensor set, including the hydro-meteorological sensor set for collecting external environmental data of the cofferdam and the structural response sensor set for collecting internal state data of the cofferdam. A model building unit, which is connected to the monitoring unit, is used to build a multi-field coupling model based on the finite element method. The multi-field coupling model dynamically couples and iterates the wave load, tidal level and seepage pressure field in the data group within a first preset time period. The decision-making unit, which is connected to the monitoring unit and the model building unit respectively, is used to calculate the difference between the minimum safety factor determined by inputting the hydrological conditions predicted after the data set and the second preset time into the multi-field coupling model and the preset safety factor, and to determine the minimum cofferdam crest elevation based on the comparison result of the difference and the preset threshold. An analysis unit, connected to the decision unit, is used to input the minimum cofferdam crest elevation into the multi-field coupling model to obtain the maximum value of the hydraulic gradient at the back slope outlet point within a third preset time period. Based on the maximum value, the seepage prevention status is determined, and the preset threshold is adjusted based on the seepage prevention status. The first preset time period is then adjusted based on the seepage prevention status after adjusting the preset threshold.

[0007] Furthermore, the model building unit also includes: a boundary condition driving module, which receives wave load time series data and tidal level difference time series data, and converts the wave load time series data and tidal level difference time series data into dynamic boundary conditions for seepage field calculation; a seepage field analysis module, which is connected to the boundary condition driving module, and calculates the seepage control equation based on the dynamic boundary conditions to determine the pore water pressure distribution and phreatic line position inside the cofferdam; a stress field analysis module, which is connected to the seepage field analysis module, and converts the pore water pressure distribution into seepage volume forces acting on the soil skeleton and determines the displacement field and stress field of the cofferdam based on the external environmental data; and a coupling module. The module is connected to the seepage field analysis module and the stress field analysis module, respectively, to calculate the volumetric strain of each finite element based on the stress field and the displacement field, and to periodically update the porosity of the corresponding finite element based on the volumetric strain of each finite element, and to calculate the corresponding permeability coefficient; the feedback module is connected to the seepage field analysis module and the coupling module, respectively, to feed back the permeability coefficient to the seepage field analysis module, and to iterate the coupling module at least once every time step within the first preset time period, until the difference of the displacement field corresponding to two consecutive iterations is less than the tolerance or the total iteration time is equal to the first preset time period and the iteration stops.

[0008] Furthermore, the decision-making unit further includes: a judgment module, which is used to run the multi-field coupling model based on a set initial cofferdam crest elevation to determine a minimum safety factor; an adjustment module, which is connected to the judgment module, and is used to adjust the initial cofferdam crest elevation based on the comparison result of the minimum safety factor and a preset safety factor; and an iteration module, which is connected to the judgment module and the adjustment module respectively, and cyclically executes the judgment module and the adjustment module at least once based on the adjusted initial cofferdam crest elevation until the difference between the minimum safety factor determined during iteration and the preset safety factor is greater than zero and less than or equal to the preset threshold, and stops the iteration, and determines the cofferdam crest elevation determined after the iteration stops as the minimum cofferdam crest elevation.

[0009] Furthermore, the analysis unit is also used to calculate the variance of the maximum value of the hydraulic gradient at the outlet point of the back slope within the third preset time period when the seepage prevention status is determined to be unqualified; the analysis unit is also used to adjust the preset threshold based on the ratio of the variance to the preset variance when the variance is less than the preset variance; wherein, the maximum value of the hydraulic gradient at the outlet point of the back slope within the third preset time period is greater than the preset value when the seepage prevention status is determined to be unqualified.

[0010] Furthermore, the analysis unit is also used to reduce the preset threshold based on the ratio of the variance to the preset variance, and the reduction of the preset threshold is inversely proportional to the ratio.

[0011] Furthermore, the analysis unit is also used to repeatedly adjust the preset threshold at least once if the seepage prevention status is unqualified after adjusting the preset threshold, until the number of adjustments is less than the preset number and the seepage prevention status is qualified, or the number of adjustments is equal to the preset number and the adjustment stops; the analysis unit is also used to plot a time-hydraulic gradient curve based on the hydraulic gradient of the back slope outlet point at multiple times within the third preset time period if the seepage prevention status is unqualified after the adjustment stops; the analysis unit is also used to calculate the integral of the curve and adjust the tolerance based on the ratio of the integral to the preset integral if the integral is greater than the preset integral.

[0012] Furthermore, the analysis unit is also used to reduce the tolerance based on the ratio of the integral to a preset integral, and the reduction in tolerance is proportional to the ratio.

[0013] Furthermore, the analysis unit is also used to obtain the difference of the displacement field corresponding to each consecutive two iterations within the first preset time period when the seepage prevention state is unqualified after adjusting the tolerance; the analysis unit is also used to calculate the average of the absolute values ​​of multiple differences and adjust the first preset time period based on the ratio of the average value to the preset average value when the average value is greater than the preset average value.

[0014] Furthermore, the analysis unit is also used to increase the first preset duration based on the ratio of the average value to the preset average value, and the increase in the first preset duration is proportional to the ratio.

[0015] Furthermore, the analysis unit is also used to obtain the number of times the maximum value of the hydraulic gradient at the back slope outlet point within the third preset time period is greater than a preset value when the seepage prevention status is unqualified after adjusting the first preset time period; the analysis unit is also used to reduce the period of the sensor group monitoring the data group based on the difference between the number of times and the preset number when the number of times is greater than the preset number of times, and the reduction of the period is proportional to the difference.

[0016] Compared with existing technologies, the advantages of this invention are as follows: The monitoring unit periodically collects external hydrological and meteorological data and internal structural response data of the cofferdam through a sensor array; the model building unit establishes a multi-field coupled model based on the finite element method, dynamically coupling wave loads, tidal levels, and seepage pressure fields; the decision unit determines the minimum cofferdam crest elevation by comparing the difference between the minimum safety factor and the preset safety factor; and the analysis unit inputs the minimum cofferdam crest elevation into the multi-field coupled model to obtain the maximum hydraulic gradient of the back slope outlet point within a third preset time period. Based on this maximum value, the seepage prevention status is determined, and relevant parameters are adjusted accordingly. This invention reduces the seepage rate of earth-rock cofferdams through real-time monitoring, prediction, and proactive control of cofferdam seepage risk.

[0017] Furthermore, this invention defines the specific implementation mechanism of the multi-field coupling model. Through a closed-loop iteration of "boundary condition driving - seepage field analysis - stress field analysis - coupling feedback", the model can realistically reflect how dynamic loads such as waves and tides affect the seepage field and structural stress inside the cofferdam, and how soil deformation reacts to the seepage characteristics, thereby further improving the accuracy and reliability of the forecast, and further reducing the leakage rate of the earth-rock cofferdam.

[0018] Furthermore, the present invention determines the iterative algorithm for the "minimum cofferdam crest elevation". Through the automated process of "judgment-adjustment-iteration", the system can intelligently find an optimal solution that meets the preset safety standards and avoids overly conservative design, which can further reduce the deviation and thus further reduce the leakage rate of the earth-rock cofferdam.

[0019] Furthermore, this invention determines whether to adjust the preset threshold based on the variance of the maximum value of the hydraulic gradient at the back slope outlet point within a third preset time period at multiple historical moments. This can more accurately determine the reasons for the failure of the seepage prevention status, enabling more effective adjustment of relevant parameters in the future, thereby further reducing the leakage rate of the earth-rock cofferdam.

[0020] Furthermore, the present invention adjusts the preset threshold based on the ratio of variance to preset variance, which enables the preset threshold to be adjusted more accurately, thereby determining the minimum cofferdam crest elevation more accurately, and further reducing the seepage rate of the earth-rock cofferdam while ensuring cost savings in engineering.

[0021] Furthermore, the present invention determines whether to adjust the tolerance based on the integral of the time-hydraulic gradient curve, which can more accurately determine the reasons for the failure of the seepage prevention status, and adjust the relevant parameters more effectively based on the reasons, thereby further reducing the leakage rate of the earth-rock cofferdam.

[0022] Furthermore, the present invention adjusts the tolerance based on the ratio of the integral to the preset integral, which makes the tolerance setting more accurate, thereby enabling the feedback module in the multi-field coupling module to iterate more effectively, making the model fit more effectively, and thus further reducing the seepage rate of the earth-rock cofferdam.

[0023] Furthermore, the present invention determines whether to adjust the preset time based on the average of the absolute values ​​of the difference between the displacement fields corresponding to two consecutive iterations within a preset time period. This can more accurately determine the reasons for the failure of the seepage prevention status and more effectively adjust the correlation coefficient based on the accurate reasons, thereby further reducing the leakage rate of the earth-rock cofferdam.

[0024] Furthermore, the present invention adjusts the preset duration based on the ratio of the average value to the preset average value, which enables the feedback module to iterate more effectively, thereby making the model results more accurate and further reducing the leakage rate of the earth-rock cofferdam.

[0025] Furthermore, the present invention adjusts the period of the sensor group monitoring data group based on the number of times the maximum value of the hydraulic gradient at the back slope outlet point exceeds a preset value within multiple preset time periods. This allows for more accurate model inferences based on more effective data, thereby further reducing the leakage rate of the earth-rock cofferdam. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the seepage prevention control system for earth-rock cofferdams according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating the steps of the seepage control method for earth-rock cofferdams according to an embodiment of the present invention. Figure 3 This is a flowchart illustrating the steps of determining the hydraulic gradient at the back slope outlet point within a third preset time period based on a comparison of the maximum value with a preset value in an embodiment of the present invention. Figure 4 This is a flowchart illustrating the steps of determining the seepage prevention status based on adjusting a preset threshold, according to an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0028] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0029] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] Please see Figure 1 As shown, it is a structural schematic diagram of the seepage prevention control system for earth-rock cofferdams according to an embodiment of the present invention.

[0031] The system includes a monitoring unit, a model building unit, a decision-making unit, and an analysis unit.

[0032] The monitoring unit is used to periodically monitor the data set based on the sensor set, including a hydro-meteorological sensor set for collecting external environmental data of the cofferdam and a structural response sensor set for collecting internal state data of the cofferdam. The model building unit is connected to the monitoring unit and is used to build a multi-field coupling model based on the finite element method. The multi-field coupling model dynamically couples and iterates the wave load, tidal level and seepage pressure field in the data group within a first preset time period. The decision-making unit is connected to the monitoring unit and the model building unit respectively. It is used to calculate the difference between the minimum safety factor determined by the data set and the preset safety factor after the hydrological conditions are predicted and input into the multi-field coupling model, and to determine the minimum cofferdam crest elevation based on the comparison result of the difference and the preset threshold. The analysis unit is connected to the decision unit and is used to input the minimum cofferdam crest elevation into the multi-field coupling model to obtain the maximum value of the hydraulic gradient of the back slope outlet point within a third preset time period. Based on the maximum value, the seepage prevention status is determined, and the preset threshold is adjusted based on the seepage prevention status. The first preset time period is also adjusted based on the seepage prevention status after adjusting the preset threshold.

[0033] Specifically, the monitoring unit includes wave gauges, tide gauges, current meters, and rainfall monitoring stations deployed inside, outside, and around the cofferdam to collect external environmental data in real time. It also includes pore water pressure gauges, earth pressure cells, strain gauges, inclinometers, and displacement monitoring points embedded in the cofferdam body and sheet piles to monitor the internal state of the cofferdam in real time, such as the phreatic line, deformation, and stress.

[0034] Specifically, the model building unit employs third-generation wave models such as the SWAN or Boussinesq equations, using measured wind fields as input to calculate the wave pressure distribution time history curves on the upstream side of the cofferdam. Based on the finite element method, the modified seepage control equations are solved, i.e. Where K is the unsaturated permeability tensor, which is the matrix suction. and effective stress This is a function that introduces the influence of stress state on permeability. Indicates water capacity and location head. This reflects the influence of gravity on seepage. The boundary conditions are: the upstream side is a time-varying pressure head boundary, determined by tidal level and wave pressure; the downstream side is a flow boundary or a known head boundary.

[0035] The seepage volume force obtained from seepage calculation and wave load As a physical load, stress-deformation analysis was performed on the dam body using the Mohr-Coulomb elastoplastic constitutive model to calculate the displacement field U and stress field. The calculated volumetric strain is used to update the porosity and permeability coefficient of the soil and fed back to the seepage field analysis module. Within one time step, iterative calculations of seepage and stress are performed until the results converge, and then the next time step is entered to achieve fully coupled analysis.

[0036] Specifically, the decision-making unit initially determines the initial cofferdam crest elevation and drives a multi-field coupled model to conduct time history analysis on the safety of the cofferdam under various possible hydrological combinations in the future, and calculates key indicators: the minimum safety factor, i.e., the minimum anti-sliding stability safety factor Fs_min of the slope. If Fs_min is less than the preset safety factor, the initial cofferdam crest elevation is automatically increased; if Fs_min is much greater than the preset safety factor, the initial cofferdam crest elevation is appropriately reduced. Based on the adjusted initial cofferdam crest elevation, the multi-field coupled model is re-driven. The iteration stops when the difference between Fs_min and the preset safety factor is controlled within a preset range, and the preset range is greater than zero and less than or equal to a preset threshold. The cofferdam crest elevation after stopping the iteration is determined as the minimum cofferdam crest elevation.

[0037] Please see Figure 2 As shown, it is a flowchart of the seepage control method for earth-rock cofferdams according to an embodiment of the present invention.

[0038] The steps of the seepage control method for earth-rock cofferdams of the present invention include: S1, periodically monitors the data group through the sensor group in the monitoring unit, wherein the sensor group includes a hydro-meteorological sensor group for collecting external environmental data of the cofferdam and a structural response sensor group for collecting internal state data of the cofferdam. S2, a multi-field coupling model is constructed based on the finite element method through the model building unit connected to the monitoring unit. The multi-field coupling model dynamically couples and iterates the wave load, tidal level and seepage pressure field in the data group within a first preset time period. S3, the decision unit connected to the monitoring unit and the model building unit respectively calculates the difference between the minimum safety factor determined by the data set and the preset safety factor, which is input into the multi-field coupling model based on the hydrological conditions predicted after the second preset time, and determines the minimum cofferdam crest elevation based on the comparison result of the difference and the preset threshold. S4, the minimum cofferdam crest elevation is input into the multi-field coupling model through the analysis unit connected to the decision unit, so as to obtain the maximum value of the hydraulic gradient of the back slope outlet point within the third preset time period, determine the seepage prevention state based on the maximum value, and adjust the preset threshold based on the seepage prevention state, and adjust the first preset time period based on the seepage prevention state after adjusting the preset threshold.

[0039] Please see Figure 3 As shown, it is a flowchart of the steps for determining the hydraulic gradient of the back slope outlet point within a third preset time period based on the comparison result with the preset value in an embodiment of the present invention.

[0040] Specifically, taking seepage control for earth-rock cofferdams as an example, the corresponding preset or critical parameter values ​​are set based on the physical performance limits of seepage control materials such as clay core walls and geomembranes, the structural tolerance requirements of cofferdams under actual wave and tidal loads, and several historical data such as the evolution of seepage lines and critical hydraulic gradients for piping occurrence obtained through statistical analysis during historical seepage monitoring and emergency response.

[0041] Specifically, taking cohesive soil as an example, the preset value L0 = 1.5 for the maximum hydraulic gradient at the outlet of the back slope within the third preset time period. The comparison process between the maximum value L and the preset value L0 based on the hydraulic gradient at the outlet of the back slope within the third preset time period is as follows: If the maximum value L of the hydraulic gradient at the outlet point of the back slope within the third preset time period is less than or equal to the preset value L0, then the seepage prevention status is determined to be qualified. If the maximum value L of the hydraulic gradient at the outlet point of the back slope is greater than the preset value L0 within the third preset time period, then the seepage prevention status is determined to be unqualified.

[0042] Specifically, when the seepage prevention status is determined to be unqualified, the variance of the maximum hydraulic gradient at the back slope outlet point within a third preset time period is calculated based on multiple historical moments. If the variance is less than the preset variance, it indicates that there is a problem with the minimum cofferdam crest elevation determined by the decision-making unit, causing the maximum hydraulic gradient at the back slope outlet point to continuously exceed the preset value. In this case, the preset threshold is adjusted based on the ratio of the variance to the preset variance. The preset ratio of the variance to the preset variance is P0 = 0.62. The comparison process between the ratio P of the variance to the preset variance and the preset ratio P0 is as follows: If the ratio P of the variance to the preset variance is less than or equal to the preset ratio P0, then the preset threshold is adjusted to 0.83 times the original preset threshold. If the ratio P of the variance to the preset variance is greater than the preset ratio P0, then the preset threshold will be adjusted to 0.91 times the original preset threshold.

[0043] Specifically, the above multiples are determined based on a comprehensive analysis of historical experience and experimental data to identify the corresponding values ​​that yielded the best results.

[0044] Please see Figure 4 The diagram shown is a flowchart illustrating the steps of determining the seepage prevention status based on adjusting a preset threshold in an embodiment of the present invention.

[0045] Specifically, after determining the seepage prevention status after adjusting the preset threshold, if the seepage prevention status is unqualified, the preset threshold is adjusted at least once until the number of adjustments is less than the preset number and the seepage prevention status is qualified, or the number of adjustments is equal to the preset number, at which point the adjustment stops. If the seepage prevention status is still unqualified after stopping the adjustment, a time-hydraulic gradient curve is plotted based on the hydraulic gradient of the back slope outlet point at multiple times within the third preset time period. The integral of the curve is calculated. If the integral is greater than the preset integral, it indicates that the hydraulic gradient has been large for a long time. The reason is that there is a problem with the feedback module in the multi-field coupling module, that is, insufficient iteration, which leads to model misfitting and thus inaccurate results. The tolerance is then adjusted based on the ratio of the integral to the preset integral. The preset ratio of the integral to the preset integral is Q0=1.4. The comparison process between the ratio Q of the integral to the preset integral and the preset ratio Q0 is as follows: If the ratio Q of the integral to the preset integral is less than or equal to the preset ratio Q0, the tolerance will be adjusted to 0.93 times the original tolerance. If the ratio Q of the integral to the preset integral is greater than the preset ratio Q0, the tolerance will be adjusted to 0.76 times the original tolerance.

[0046] Specifically, the above multiples are determined based on a comprehensive analysis of historical experience and experimental data to identify the corresponding values ​​that yielded the best results.

[0047] Specifically, the seepage prevention status after adjusting the tolerance is redefined. If the seepage prevention status is unqualified, the difference in displacement field corresponding to every two consecutive iterations within the first preset time period is obtained. The average of the absolute values ​​of multiple differences is calculated. If the average value is greater than the preset average value, it indicates that the iteration of the feedback module is still insufficient, resulting in model misfit and inaccurate model results. The first preset time period is then adjusted based on the ratio of the average value to the preset average value. The preset ratio of the average value to the preset average value is R0 = 1.89. The comparison process between the ratio R of the average value to the preset average value and the preset ratio R0 is as follows: If the ratio R of the average value to the preset average value is less than or equal to the preset ratio R0, the first preset duration is adjusted to 1.7 times the original first preset duration, and the adjusted first preset duration is rounded up. If the ratio R of the average value to the preset average value is greater than the preset ratio R0, the first preset duration will be adjusted to 2.5 times the original first preset duration, and the adjusted first preset duration will be rounded up.

[0048] Specifically, the above multiples are determined based on a comprehensive analysis of historical experience and experimental data to identify the corresponding values ​​that yielded the best results.

[0049] Specifically, the seepage prevention status is redefined after the first preset time period. If the seepage prevention status is unqualified, the number of times the maximum value of the hydraulic gradient at the back slope outlet point within the third preset time period is greater than the preset value is obtained. If the number is greater than the preset number, it indicates that if the predicted value deviates significantly from the subsequent measured value for several consecutive cycles, especially when the external environment changes rapidly, it means that the "old data" on which the model is based can no longer effectively predict the "new state," and the monitoring cycle can no longer keep up with the speed of environmental change. Therefore, the monitoring cycle of the sensor group is adjusted based on the difference between the number of times and the preset number. The preset difference T0 between the number of times and the preset number is 3. The comparison process between the difference T and the preset difference T0 is as follows: If the difference T between the number of times and the preset number of times is less than or equal to the preset difference T0, the period of the sensor group monitoring data group will be adjusted to 0.87 times the original period, and the adjusted period will be rounded up. If the difference T between the number of times and the preset number of times is greater than the preset difference T0, the period of the sensor group monitoring data group will be adjusted to 0.64 times the original period, and the adjusted period will be rounded up.

[0050] Specifically, the above multiples are determined based on a comprehensive analysis of historical experience and experimental data to identify the corresponding values ​​that yielded the best results.

[0051] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A seepage prevention control system for earth-rock cofferdams, characterized in that, include: The monitoring unit is used to periodically monitor the data set based on the sensor set, including the hydro-meteorological sensor set for collecting external environmental data of the cofferdam and the structural response sensor set for collecting internal state data of the cofferdam. A model building unit, which is connected to the monitoring unit, is used to build a multi-field coupling model based on the finite element method. The multi-field coupling model dynamically couples and iterates the wave load, tidal level and seepage pressure field in the data set within a first preset time period. The decision-making unit, which is connected to the monitoring unit and the model building unit respectively, is used to calculate the difference between the minimum safety factor determined by inputting the hydrological conditions predicted after the data set and the second preset time into the multi-field coupling model and the preset safety factor, and to determine the minimum cofferdam crest elevation based on the comparison result of the difference and the preset threshold. An analysis unit, connected to the decision unit, is used to input the minimum cofferdam crest elevation into the multi-field coupling model to obtain the maximum value of the hydraulic gradient at the back slope outlet point within a third preset time period. Based on the maximum value, the seepage prevention status is determined, and the preset threshold is adjusted based on the seepage prevention status. The first preset time period is then adjusted based on the seepage prevention status after adjusting the preset threshold.

2. The seepage prevention control system for earth-rock cofferdams according to claim 1, characterized in that, The model building unit also includes: The boundary condition driving module is used to receive wave load time series data and tidal level difference time series data, and convert the wave load time series data and the tidal level difference time series data into dynamic boundary conditions for seepage field calculation. The seepage field analysis module, which is connected to the boundary condition driving module, is used to calculate the seepage control equation based on the dynamic boundary conditions in order to determine the pore water pressure distribution and the location of the phreatic line inside the cofferdam. The stress field analysis module, which is connected to the seepage field analysis module, is used to convert the pore water pressure distribution into seepage volume forces acting on the soil skeleton and the external environmental data to determine the displacement field and stress field of the cofferdam. A coupling module, which is connected to the seepage field analysis module and the stress field analysis module respectively, is used to calculate the volumetric strain of each finite element based on the stress field and the displacement field, and to periodically update the porosity of the corresponding finite element based on the volumetric strain of each finite element, and to calculate the corresponding permeability coefficient. The feedback module is connected to the seepage field analysis module and the coupling module respectively, and is used to feed back the permeability coefficient to the seepage field analysis module. The coupling module is iterated at least once every time step within the first preset time period until the difference between the displacement fields corresponding to two consecutive iterations is less than the tolerance or the total iteration time is equal to the first preset time period and the iteration stops.

3. The seepage prevention control system for earth-rock cofferdams according to claim 2, characterized in that, The decision-making unit also includes: The judgment module is used to run the multi-field coupled model based on the set initial cofferdam crest elevation to determine the minimum safety factor; An adjustment module, which is connected to the judgment module, is used to adjust the initial cofferdam crest elevation based on the comparison result between the minimum safety factor and the preset safety factor. An iteration module, which is connected to the judgment module and the adjustment module respectively, executes the judgment module and the adjustment module at least once based on the adjusted initial cofferdam crest elevation, until the difference between the minimum safety factor determined during iteration and the preset safety factor is greater than zero and less than or equal to the preset threshold, and stops the iteration, and determines the cofferdam crest elevation determined after the iteration stops as the minimum cofferdam crest elevation.

4. The seepage prevention control system for earth-rock cofferdams according to claim 3, characterized in that, The analysis unit is also used to calculate the variance of the maximum value of the hydraulic gradient at the back slope outlet point within the third preset time period when it is determined that the seepage prevention status is unqualified. The analysis unit is also used to adjust the preset threshold based on the ratio of the variance to the preset variance when the variance is less than the preset variance. If the maximum value of the hydraulic gradient at the outlet point of the back slope within the third preset time period is greater than the preset value, the seepage prevention status is deemed unqualified.

5. The seepage prevention control system for earth-rock cofferdams according to claim 4, characterized in that, The analysis unit is also used to reduce the preset threshold based on the ratio of the variance to the preset variance, and the reduction of the preset threshold is inversely proportional to the ratio.

6. The seepage prevention control system for earth-rock cofferdams according to claim 5, characterized in that, The analysis unit is also used to repeatedly adjust the preset threshold at least once if the seepage prevention status is not qualified after adjusting the preset threshold, until the adjustment is stopped when the number of adjustments is less than the preset number and the seepage prevention status is qualified or the number of adjustments is equal to the preset number. The analysis unit is also used to plot a time-hydraulic gradient curve based on the hydraulic gradient of the back slope outlet point at multiple times within the third preset time period when the seepage prevention state is unqualified after the adjustment is stopped. The analysis unit is also used to calculate the integral of the curve and, if the integral is greater than a preset integral, to adjust the tolerance based on the ratio of the integral to the preset integral.

7. The seepage prevention control system for earth-rock cofferdams according to claim 6, characterized in that, The analysis unit is also used to reduce the tolerance based on the ratio of the integral to a preset integral, and the reduction in tolerance is proportional to the ratio.

8. The seepage prevention control system for earth-rock cofferdams according to claim 7, characterized in that, The analysis unit is also used to obtain the difference in the displacement field corresponding to each consecutive two iterations within the first preset time period when the seepage prevention state is unqualified after adjusting the tolerance. The analysis unit is also used to calculate the average of the absolute values ​​of multiple differences and, if the average value is greater than a preset average value, to adjust the first preset duration based on the ratio of the average value to the preset average value.

9. The seepage prevention control system for earth-rock cofferdams according to claim 8, characterized in that, The analysis unit is also used to increase the first preset duration based on the ratio of the average value to the preset average value, and the increase in the first preset duration is proportional to the ratio.

10. The seepage prevention control system for earth-rock cofferdams according to claim 9, characterized in that, The analysis unit is also used to obtain the number of times the maximum value of the hydraulic gradient at the back slope outlet point within the third preset time period is greater than the preset value when the seepage prevention status is unqualified after adjusting the first preset time period. The analysis unit is also used to reduce the period of the sensor group monitoring the data group based on the difference between the number of times and the preset number of times when the number of times exceeds the preset number of times, and the reduction in period is proportional to the difference.

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