A method and system for evaluating the overall resilience of a dike based on a multi-failure mode

Abstract

The application provides a kind of embankment overall toughness evaluation method and system based on multiple failure modes, comprising: collecting embankment basic data, dividing embankment into several embankment sections, evaluating the importance of each embankment section basic failure mode, obtaining influence factor;Obtain the embankment response parameter of each embankment section under given wave for different basic failure modes;Compare the vulnerability curve corresponding to the basic failure mode, obtain the damage level and its probability distribution of different failure modes of embankment section;From the three dimensions of casualty rate, economic loss rate and repair efficiency, analyze the loss caused by different damage levels;Calculate embankment section safety evaluation index and embankment section repair evaluation index and form overall evaluation index, qualitative evaluation embankment toughness.The application considers the attribute difference of different sections of embankment, measures the complexity of different failure modes of embankment, evaluates the toughness level of embankment under wave action from three dimensions, the method has strong logic and high feasibility, provides important reference for actual embankment engineering.

Description

Technical Field

[0001] This invention relates to the field of building evaluation technology, and more specifically, to a method and system for evaluating the overall resilience of embankments based on multiple failure modes. Background Technology

[0002] To address the climate crisis and ensure the safety and stability of waterfront areas, a comprehensive method for assessing the overall resilience of levees is urgently needed. On the one hand, the wave-levee interaction mechanism is complex, and levee failure occurs in various modes. Current levee assessment methods often only evaluate a single failure mode, failing to encompass the impact of multiple failure modes on levee resilience. On the other hand, existing levee assessment techniques focus only on the resilience level of a single levee, without considering the overall resilience level of the levee system in a given area. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for evaluating the overall resilience of dikes based on multiple failure modes.

[0004] According to one aspect of the present invention, a method for evaluating the overall toughness of a dike based on multiple failure modes is provided, comprising:

[0005] Collect basic data on the dikes, divide the dikes into several sections based on typical cross sections, assess the importance of the basic failure modes of each section, and obtain the influencing factors.

[0006] Obtain the levee response parameters for each levee segment under different basic failure modes under a given wave;

[0007] By comparing the levee response parameters with the vulnerability curves corresponding to the basic failure modes, the damage levels and probability distributions of different failure modes of the levee section are obtained.

[0008] The analysis focuses on the losses caused by different damage levels from three dimensions: casualty rate, economic loss rate, and repair efficiency.

[0009] Based on the influencing factors, the levee response parameters, the losses and probability distribution caused by different damage levels, the casualty rate, the economic loss rate, and the repair efficiency, the levee section safety assessment index and the levee section repair assessment index are calculated. The overall assessment index is formed by combining the safety assessment index and the repair assessment index of all levee sections to conduct a qualitative assessment of the levee resilience.

[0010] Preferably, the basic information of the dike is information that affects the performance of the dike, including historical disaster information, meteorological and hydrological data, engineering topography and geology, dike construction materials, geometric dimensions and cross-sectional type;

[0011] The process of dividing the dike into several sections based on typical cross-sections involves determining whether each section shares the same typical cross-section. The principle for determining whether a section shares the same typical cross-section is as follows:

[0012] For the same type of embankment construction material, the variation in material parameters shall not exceed 5%;

[0013] The cross-sectional shapes of the dikes are the same, and the variation in cross-sectional geometric dimensions does not exceed 5%.

[0014] The underlying foundation soil is of the same type, and the variation in its properties does not exceed 10%.

[0015] The potential wave characteristics within the levee section should not vary by more than 5%.

[0016] The basic failure modes include wave failure, slip failure, rock instability and foundation scour;

[0017] The influencing factor refers to the assessment of the importance of the basic failure mode of the dike. This influencing factor is related to dike performance, dike failure mechanism, and basic dike data, and is calculated using the following formula:

[0018]

[0019] In the formula, N represents the influencing factor corresponding to failure mode j of levee segment k. k n represents the total number of times the dike section k has been damaged in history. j This represents the number of times destruction mode j occurs.

[0020] Preferably, the levee response parameters refer to parameters that reflect changes in levee performance when a certain failure mode occurs under wave action. The types of levee response parameters correspond to the basic failure modes: the levee response parameters corresponding to overtopping failure, slippage failure, rock instability and foundation scour are overtopping amount, slippage amount, rock erosion index and scour rate, respectively.

[0021] The overtopping volume refers to the average unit width discharge of waves over the crest of the levee along its length, denoted by the parameter Q, and measured in meters (m). 3 / (m·s);

[0022] The slippage refers to the horizontal displacement of the dike along its width under the action of waves, denoted by the parameter S, and the unit is m;

[0023] The rock erosion index is calculated by the following formula:

[0024]

[0025] In the formula, E r The erosion index of boulders is a dimensionless parameter, where A is the cross-sectional erosion area in m². 2 Dn50 The nominal diameter of the stone block is in meters (m).

[0026] The scouring rate is calculated by the following formula:

[0027] D = Z mf / B m

[0028] In the formula, D is the scouring rate, which is a dimensionless parameter, and Z... mf Maximum scour depth, in meters (m), B m The average width of the embankment is expressed in meters.

[0029] The dike response parameters are obtained through formulas, numerical models, physical models, or post-disaster field measurements.

[0030] Preferably, the vulnerability curve establishes the relationship between the dike response parameters and the actual damage state based on a critical threshold, wherein the critical threshold is the standard for classifying the dike damage state into different damage levels;

[0031] The critical threshold refers to the dike response parameter corresponding to a certain extreme damage state, and is classified into levels according to the degree of impact; the vulnerability curve follows a log-normal distribution, and the median and log standard deviation corresponding to different damage levels of the basic failure mode are obtained based on the critical threshold.

[0032] Preferably, the step of comparing the levee response parameters with the vulnerability curves corresponding to the basic failure modes to obtain the damage levels and probability distributions of different failure modes of the levee section includes:

[0033] The exceedance probabilities corresponding to the obtained levee response parameters are read from the vulnerability curves for different damage levels. The difference between the exceedance probabilities of the two lines is the probability of a certain damage level, calculated according to the following formula:

[0034]

[0035] In the formula, RP refers to the type of levee response parameters. The levee response parameters obtained by levee segment k under failure mode j. Let P be the probability that the damage level is i given the levee response parameters in damage mode j. i It is the exceedance probability read on the i-th fragility curve, P i+1 It is the exceedance probability read on the i+1 level vulnerability curve;

[0036] When i = 0, take P0 = 1. This represents the probability that the dike will not be damaged, when i = max.

[0037] Preferably, the casualty rate, economic loss rate, and repair efficiency are performance indicators determined by the dike damage mode, and exhibit a probability distribution as the damage level, economic cost, basic dike data, and dike scale change.

[0038] Based on the performance indicators that present a probability distribution: casualty rate, economic loss rate, and repair efficiency, a loss curve corresponding to the basic damage mode of the dike is obtained.

[0039] The loss curves follow a log-normal distribution, and each performance index corresponds to a different median and log standard deviation under different failure modes.

[0040] Preferably, the calculation of the embankment safety assessment index and the embankment repair assessment index includes:

[0041] Calculate the loss results C for embankment segment k in terms of casualty rate, economic loss rate, and repair efficiency. k E k R k :

[0042]

[0043]

[0044]

[0045] The influencing factors of different failure modes j in section k of the embankment. Let the parameters be the levee response parameters for different failure modes j of levee segment k. The casualty rate, economic loss rate, and repair efficiency corresponding to different damage levels i under different damage modes j;

[0046] Safety assessment index SA of the levee section k The loss outcome, determined by the casualty rate, is expressed by the following formula:

[0047] SA k =C k

[0048] The decision ratio f is based on the economic loss rate and the repair efficiency. E f R The levee repair assessment index RA k for:

[0049] RA k =f E E k +f R R k

[0050] In the formula, f E f Rare respectively the decision proportions of the economic loss rate and the repair efficiency, and there is a relationship of f E +f R =1 between the parameters.

[0051] Preferably, the integrating of all the embankment section results to form an overall evaluation index to perform qualitative evaluation on embankment resilience includes:

[0052] performing weighted calculation on the embankment section safety evaluation index SA k and the embankment section repair evaluation index RA k to obtain an embankment overall safety evaluation index SA and an overall repair evaluation index RA, where the calculation formula is as follows:

[0053]

[0054]

[0055] where l k is the length of the embankment section k, and L is the total length of the embankment;

[0056] The overall safety evaluation index SA and the overall repair evaluation index RA quantitatively evaluate the overall resilience level of the embankment under wave action, where a larger SA represents a weaker ability of the embankment to ensure safety, and a larger RA represents a greater difficulty in repairing the embankment after a disaster.

[0057] Preferably, the performing qualitative evaluation on embankment resilience includes:

[0058] The qualitative evaluation criteria are:

[0059] SA≤1×10 -5 and RA≤5%, resilience level 1;

[0060] SA≤1×10 -4 and RA≤10%, resilience level 2;

[0061] SA≤1×10 -4 and 10%<RA≤30%, resilience level 3;

[0062] SA≤1×10 -4 and 30%<RA≤50%, resilience level 4;

[0063] SA>1×10 -4 or RA>50%, resilience level 5.

[0064] According to a second aspect of the present invention, an embankment overall resilience evaluation system based on multiple failure modes is provided, comprising:

[0065] The damage analysis module collects basic data on the dike, divides the dike into several sections based on typical cross-sections, assesses the importance of the basic damage modes of each section, and obtains the influencing factors.

[0066] The response analysis module obtains the levee response parameters for different basic failure modes of each levee segment under a given wave, based on formulas, numerical models, physical models, or post-disaster field measurements.

[0067] The vulnerability analysis module compares the levee response parameters with the vulnerability curves corresponding to the basic failure modes to obtain the damage level and probability distribution of different failure modes of the levee section.

[0068] The loss analysis module analyzes the losses caused by different damage levels from three dimensions: casualty rate, economic loss rate, and repair efficiency.

[0069] The comprehensive evaluation module calculates the safety assessment index and the repair assessment index of the dike section based on the influencing factors, the dike response parameters, the losses and probability distribution caused by different damage levels, the casualty rate, the economic loss rate, and the repair efficiency. It then integrates all the safety assessment index and the repair assessment index of the dike section to form an overall assessment index, thereby qualitatively assessing the dike's resilience.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] This invention provides a method and system for assessing the overall resilience of dikes considering multiple failure modes, based on three performance indicators: casualty rate, economic loss rate, and repair efficiency. The method and system include five stages: failure analysis, response analysis, vulnerability analysis, loss analysis, and comprehensive evaluation. The dike resilience assessment is divided into three levels: different dike sections, different failure modes, and different damage levels. The overall dike resilience assessment result is obtained by combining performance indicators. This method is logically rigorous, scientifically sound, and highly operable, providing an evaluation method for building highly resilient riverside dike systems and possessing significant practical application value. Attached Figure Description

[0072] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0073] Figure 1 This is a flowchart illustrating a method for evaluating the overall toughness of a dike based on multiple failure modes, according to an embodiment of the present invention.

[0074] Figure 2 The following are schematic diagrams of two typical cross-sections of a dike in a specific embodiment, wherein (a) is a caisson-type vertical dike and (b) is a sloping dike constructed of twisted I-beam blocks.

[0075] Figure 3 The vulnerability curves corresponding to the basic failure modes of specific embodiments are shown below, where (a) is the wave overtopping vulnerability curve, (b) is the slippage vulnerability curve, (c) is the rock erosion index vulnerability curve, and (d) is the scour rate vulnerability curve.

[0076] Figure 4 The casualty rate loss curves are for specific embodiments, where (a) corresponds to the failure mode of overtopping failure and foundation scour, and (b) corresponds to the failure mode of sliding failure and boulder instability.

[0077] Figure 5 The economic loss rate curves are for specific embodiments, where (a) corresponds to wave failure, (b) corresponds to slip failure, (c) corresponds to rock instability, and (d) corresponds to foundation scour.

[0078] Figure 6 The repair efficiency loss curves are for specific embodiments, where (a) corresponds to the overtopping failure mode, (b) corresponds to the slip failure and rock instability mode, and (c) corresponds to the foundation scour mode. Detailed Implementation

[0079] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0080] To better assess regional stability, levee resilience evaluation can proceed from point to line, studying the overall resilience level of the levee system within a region, thus providing a more intuitive display of the levee's disaster resilience. Based on this, this invention provides a method for evaluating the overall resilience of levees based on multiple failure modes. This method divides the levee into different sections, studies the probability of different damages occurring for each section under various failure modes, analyzes the losses caused by different damages based on three performance indicators: casualty rate, economic loss rate, and repair efficiency, and finally integrates the results of all levee sections, considering both safety and repair difficulty, to form an overall levee resilience evaluation.

[0081] Based on the above-described inventive concept, this invention provides an embodiment of a method for evaluating the overall toughness of dikes based on multiple failure modes. (See also...) Figure 1 This includes the following steps:

[0082] The first step is damage analysis, which involves collecting basic data on the dike, dividing the dike into several sections based on typical cross-sections, assessing the importance of the basic damage modes of each section, and obtaining the influencing factors.

[0083] The second step is response analysis, which obtains the levee response parameters for different basic failure modes of each levee segment under a given wave.

[0084] The third step is vulnerability analysis, which compares the response parameters with the vulnerability curves corresponding to the basic failure modes to obtain the damage level and probability distribution of different failure modes of the embankment section.

[0085] The fourth step is loss analysis, which analyzes the losses caused by different levels of damage from three dimensions: casualty rate, economic loss rate, and repair efficiency.

[0086] The fifth step is a comprehensive evaluation. Based on the influencing factors in the first step, the levee response parameters in the second step, the losses and probability distribution caused by different damage levels in the third step, and the casualty rate, economic loss rate, and repair efficiency in the fourth step, the safety assessment index and the repair assessment index of the levee section are calculated. The overall assessment index is formed by combining the safety assessment index and the repair assessment index of all levee sections to conduct a qualitative assessment of the levee's resilience.

[0087] This embodiment takes into account the resilience level of the dikes on a macro level, and has great reference value for the design, renovation and repair of regional dike systems in coastal, lakeside and riverside towns.

[0088] In a preferred embodiment of the present invention, the first step, damage analysis, specifically includes the following process:

[0089] S11, Collect basic information about the dikes.

[0090] Basic information about dikes includes historical disaster data, meteorological and hydrological data, engineering topography and geology, dike construction materials, geometric dimensions, cross-sectional type, and other information that affects the performance of dikes.

[0091] S12 divides the dike into several sections based on typical cross-sections.

[0092] The principles for dividing embankment sections that share the same typical cross-section are as follows:

[0093] 1. The types and parameters of embankment construction materials are basically the same;

[0094] 2. The cross-sectional shapes of the dikes are the same, and the variation in cross-sectional geometric dimensions does not exceed 5%;

[0095] 3. The properties of the underlying foundation soil are basically the same;

[0096] 4. The potential wave characteristics within the levee section do not change significantly;

[0097] 5. From the perspective of simplifying the evaluation process, it can be regarded as the same dike section (that is, when some dike sections do not meet the requirements of 1-4, the decision-maker decides whether to classify them as the same dike section).

[0098] S13, assess the importance of the basic failure mode for each levee section and obtain the impact factor.

[0099] The basic failure modes described in the failure analysis phase include wave overtopping failure, slippage failure, rock bursting, and foundation scour. These basic failure modes were obtained based on data collection, mechanism studies, and expert consultation.

[0100] The impact factors mentioned in the damage analysis phase refer to the assessment of the importance of the basic damage mode of the dike. The impact factors are related to dike performance, dike failure mechanism, and basic dike data, and are calculated using the following formula:

[0101]

[0102] In the formula, N represents the influencing factor corresponding to failure mode j of levee segment k. k n represents the total number of times the dike section k has been damaged in history. j This represents the number of times destruction mode j occurs.

[0103] In a preferred embodiment of the present invention, the second step, response analysis, is performed. Dike response parameters refer to parameters reflecting changes in dike performance when a certain failure mode occurs under wave action. The types of dike response parameters correspond to the basic failure modes. The four basic failure modes are overtopping failure, slippage failure, rockfall instability, and foundation scour. The corresponding types of dike response parameters are overtopping amount, slippage amount, rockfall erosion index, and scour rate, respectively.

[0104] The aforementioned wave overtopping refers to the average unit width discharge of waves over the top of the levee along the length of the levee, denoted by the parameter Q, and measured in meters. 3 / (m·s).

[0105] The aforementioned slippage refers to the horizontal displacement of the dike along its width under the action of waves, denoted by the parameter S, and the unit is m.

[0106] The above-mentioned erosion index of boulders is calculated by the following formula:

[0107]

[0108] In the formula, E r The erosion index of boulders is a dimensionless parameter, where A is the cross-sectional erosion area in m². 2 D n50 The nominal diameter of the stone block is expressed in meters (m).

[0109] The above-mentioned scouring rate is calculated by the following formula:

[0110] D = Z mf / B m

[0111] In the formula, D is the scouring rate, which is a dimensionless parameter, and Z... mf Maximum scour depth, in meters (m), B m The average width of the embankment is expressed in meters (m).

[0112] Furthermore, the levee response parameters mentioned in the response analysis phase can be obtained through formulas, numerical models, physical models, or post-disaster field measurements. The formulas should have high industry usage rates, the numerical models should have high accuracy, and the physical models and post-disaster field measurements should be averaged multiple times. Generally, numerical models include finite element numerical models, fluid dynamics numerical models, etc.; physical models refer to field tests.

[0113] In a preferred embodiment of the present invention, the third step, vulnerability analysis, is performed, and the specific process includes:

[0114] S31, Establish the fragility curve.

[0115] The vulnerability curve establishes the relationship between the levee response parameters and the actual damage state based on the critical threshold. The critical threshold is the standard for classifying the levee damage state into different damage levels.

[0116] The critical threshold refers to the dike response parameter corresponding to a certain extreme damage state, and it should be classified according to the degree of impact.

[0117] In a preferred embodiment, the critical threshold is divided into three levels. Based on the four basic failure modes mentioned above: wave failure, slip failure, rock instability, and foundation scour, the classification principle of the critical threshold is as follows:

[0118] Overtopping: When the threshold level is 1, overtopping is likely to affect particularly important areas behind the dike; when the threshold level is 2, overtopping is likely to affect generally important areas behind the dike; when the threshold level is 3, overtopping is likely to affect other areas behind the dike or threaten structural safety.

[0119] Slippage: When the threshold level is 1, the dike basically does not need to be repaired; when the threshold level is 2, the dike can be repaired using simple methods; when the threshold level is 3, the dike is more difficult to repair.

[0120] Rock erosion index: When the threshold level is 1, a small portion of the rocks in the dike become unstable and fall off; when the threshold level is 2, a portion of the rocks in the dike become unstable and fall off; when the threshold level is 3, most of the rocks in the dike become unstable and fall off, exposing the filter layer.

[0121] Scouring rate: When the threshold level is 1, the foundation experiences slight scouring and loss, which does not affect the stability of the embankment; when the threshold level is 2, the foundation experiences significant scouring and loss, which affects the local stability of the embankment; when the threshold level is 3, the foundation experiences severe scouring and loss, which affects the stability of the embankment.

[0122] In a preferred embodiment, the vulnerability curves follow a log-normal distribution, providing the median and log-standard deviation of the vulnerability curves corresponding to different damage levels of the basic failure mode. Specifically:

[0123] Overtopping failure: When damage level i = 1, the median overtopping amount is 0.005m. 3 / (m·s), with a logarithmic standard deviation of 0.53; when damage level i=2, the median overflight volume is 0.01m. 3 / (m·s), with a logarithmic standard deviation of 0.46; when damage level i=3, the median overflight volume is 0.05m. 3 / (m·s), with a logarithmic standard deviation of 0.30.

[0124] Slip failure: When damage level i = 1, the median slip is 0.1 m and the logarithmic standard deviation is 0.46; when damage level i = 2, the median slip is 0.5 m and the logarithmic standard deviation is 0.28; when damage level i = 3, the median slip is 1 m and the logarithmic standard deviation is 0.2.

[0125] Rock instability: When the damage level i = 1, the median value of the rock erosion index is 2, and the log standard deviation is 0.14; when the damage level i = 2, the median value of the rock erosion index is 4, and the log standard deviation is 0.28; when the damage level i = 3, the median value of the rock erosion index is 8, and the log standard deviation is 0.21.

[0126] Foundation scour: When damage level i = 1, the median scour rate is 5%, and the logarithmic standard deviation is 0.30; when damage level i = 2, the median scour rate is 10%, and the logarithmic standard deviation is 0.46; when damage level i = 3, the median scour rate is 20%, and the logarithmic standard deviation is 0.32.

[0127] S32, obtain the damage level and probability distribution of different failure modes of the embankment section.

[0128] The damage level and its probability distribution should be obtained from the vulnerability curves of different damage levels, corresponding to the exceedance probabilities of the levee response parameters. The difference between the exceedance probabilities of the two lines is the probability of a certain damage level, which can be calculated according to the following formula:

[0129]

[0130] In the formula, RP refers to the type of levee response parameters. This refers to the levee segment k under failure mode j, based on the obtained levee response parameters. Let P be the probability that the damage level is i given the levee response parameters in damage mode j. i It is the exceedance probability read on the i-th fragility curve, P i+1It is the exceedance probability read on the i+1 level vulnerability curve.

[0131] Specifically, when i = 0, P0 = 1. This represents the probability that the dike will not be damaged, when i = max.

[0132] In a preferred embodiment of the present invention, the fourth step, loss analysis, is performed, and the specific process includes:

[0133] S41, Establish the loss curve.

[0134] The casualty rate, economic loss rate, and repair efficiency in the loss analysis phase are performance indicators determined by the dike failure mode, and they exhibit a probability distribution that varies with the damage level, economic cost, basic dike data, and dike scale. The casualty rate refers to the ratio of casualties within the dike's impact area to the total population. The economic loss rate consists of the ratio of property damage in the dike's area and dike repair costs to the overall construction cost of the dike. Repair efficiency is the ratio of post-disaster repair time to the construction time of the dike being evaluated.

[0135] In a preferred embodiment, based on performance indices exhibiting probability distributions, loss curves corresponding to the basic failure modes of the dike are provided. These loss curves follow a log-normal distribution, and the median and log-standard deviation of different performance indices under different failure modes are as follows:

[0136] Casualty rate: For wave overtopping failure and foundation scour, the median value is 1 × 10⁻⁶ for damage level i = 1. -5 With a logarithmic standard deviation of 0.46, the median value for damage grade i = 2 is 1 × 10⁻⁶. -4 With a logarithmic standard deviation of 0.37, the median value for damage grade i = 3 is 1 × 10⁻⁶. -3 The logarithmic standard deviation was 0.14; for slip failure and rock instability, the median value was 1 × 10 for damage level i = 1. -6 With a logarithmic standard deviation of 0.55, the median value for damage grade i = 2 is 1 × 10⁻⁶. -5 With a logarithmic standard deviation of 0.46, the median value for damage grade i = 3 is 1 × 10⁻⁶. -4 The logarithmic standard deviation is 0.18.

[0137] Economic loss rates: For wave failure, the median value is 10% with a logarithmic standard deviation of 0.46 when damage level i=1; 25% with a logarithmic standard deviation of 0.42 when damage level i=2; and 60% with a logarithmic standard deviation of 0.15 when damage level i=3. For slip failure, the median value is 5% with a logarithmic standard deviation of 0.60 when damage level i=1; 15% with a logarithmic standard deviation of 0.57 when damage level i=2; and 30% with a logarithmic standard deviation of 0.36 when damage level i=3. For rock instability, the median value is 5% with a logarithmic standard deviation of 0.60 when damage level i=1; 10% with a logarithmic standard deviation of 0.46 when damage level i=2; and 20% with a logarithmic standard deviation of 0.48 when damage level i=3. For foundation scour, the median value is 5% when the damage level i = 1, and the logarithmic standard deviation is 0.60; the median value is 25% when the damage level i = 2, and the logarithmic standard deviation is 0.42; and the median value is 60% when the damage level i = 3, and the logarithmic standard deviation is 0.15.

[0138] Repair efficiency: For wave-induced failure, the median value is 5% with a logarithmic standard deviation of 0.30 when damage level i=1; 10% with a logarithmic standard deviation of 0.23 when damage level i=2; and 30% with a logarithmic standard deviation of 0.12 when damage level i=3. For slippage failure and rock instability, the median value is 5% with a logarithmic standard deviation of 0.30 when damage level i=1; 15% with a logarithmic standard deviation of 0.19 when damage level i=2; and 30% with a logarithmic standard deviation of 0.12 when damage level i=3. For foundation scour, the median value is 10% with a logarithmic standard deviation of 0.46 when damage level i=1; 30% with a logarithmic standard deviation of 0.24 when damage level i=2; and 70% with a logarithmic standard deviation of 0.11 when damage level i=3.

[0139] S42, combining basic data on dikes and market economic conditions, optimizes the casualty rate, economic loss rate, and repair efficiency for different damage levels on the loss curve.

[0140] In a preferred embodiment of the present invention, the fifth step, comprehensive analysis, is carried out, and the specific process is as follows:

[0141] S51, calculate the safety assessment index and the repair assessment index of the embankment section.

[0142] The calculation process and formulas for the safety assessment index and the repair assessment index of the embankment section are as follows:

[0143] Collect basic data on the dikes, divide the dikes into several sections, and obtain the typical cross-section of the dike section k to be evaluated;

[0144] The basic failure mode of levee segment k was obtained and its influencing factors were evaluated. The influencing factors of different failure modes j were also obtained.

[0145] For different failure modes j, response analysis is conducted on typical cross-sections of levee k using formulas, numerical models, physical models, or post-disaster field measurements to obtain levee response parameters.

[0146] Based on various levee response parameters By comparing with the fragility curve, the damage level is obtained. probability

[0147] Based on the actual conditions of the levee section, the casualty rates corresponding to different damage levels i under different failure modes j are optimized. Economic loss rate Repair efficiency

[0148] Calculate the loss results C for embankment segment k in terms of casualty rate, economic loss rate, and repair efficiency according to the following formulas. k E k R k :

[0149]

[0150]

[0151]

[0152] Safety assessment index SA of the levee section k The loss outcome, determined by the casualty rate, is expressed by the following formula:

[0153] SA k =C k

[0154] The decision ratio f is based on the economic loss rate and the repair efficiency. E f R The levee repair assessment index RA k for:

[0155] RA k =f E E k +f R R k

[0156] In the formula, f E f R These are the decision ratios for economic loss rate and repair efficiency, respectively, and there is an f relationship between the parameters. E +f R =1.

[0157] In S52, all results of the levee sections are integrated to form an overall evaluation index.

[0158] For the levee section safety evaluation index SA obtained in S51 k and the levee section restoration evaluation index RA k weighted calculation is performed to obtain the overall levee safety evaluation index SA and the overall restoration evaluation index RA, and the calculation formula is as follows:

[0159]

[0160]

[0161] In the formula, l k is the length of the levee section k, and L is the total length of the levee.

[0162] The above indexes quantitatively evaluate the overall resilience level of the levee under wave action. A larger SA indicates a weaker ability of the levee to ensure safety, and a larger RA indicates a greater difficulty in restoring the levee after a disaster.

[0163] In S53, qualitative evaluation is performed on the levee resilience.

[0164] In the comprehensive evaluation stage, the qualitative evaluation adopts the following criteria:

[0165] SA≤1×10 -5 and RA≤5%, resilience level 1;

[0166] SA≤1×10 -4 and RA≤10%, resilience level 2;

[0167] SA≤1×10 -4 and 10%<RA≤30%, resilience level 3;

[0168] SA≤1×10 -4 and 30%<RA≤50%, resilience level 4;

[0169] SA>1×10 -4 or RA>50%, resilience level 5.

[0170] Based on the same inventive concept, in other embodiments of the present invention, a levee overall resilience evaluation system based on multiple failure modes is provided, comprising a failure analysis module, a response analysis module, a vulnerability analysis module, a loss analysis module and a comprehensive evaluation module. Wherein:

[0171] The failure analysis module is configured to collect basic data of the levee, divide the levee into a plurality of levee sections according to typical sections, evaluate the importance degree of the basic failure mode of each of the levee sections, and obtain an influence factor;

[0172] The response analysis module obtains the levee response parameters for different basic failure modes of each levee segment under a given wave, based on formulas, numerical models, physical models, or post-disaster field measurements.

[0173] The vulnerability analysis module compares the levee response parameters with the vulnerability curves corresponding to the basic failure modes to obtain the damage level and probability distribution of different failure modes of the levee section.

[0174] The loss analysis module analyzes the losses caused by different damage levels from three dimensions: casualty rate, economic loss rate, and repair efficiency.

[0175] The comprehensive evaluation module calculates the safety assessment index and repair assessment index of the dike section based on influencing factors, response parameters, losses and probability distribution caused by different damage levels, casualty rate, economic loss rate, and repair efficiency. It integrates the safety assessment index and repair assessment index of all dike sections to form an overall assessment index, and conducts a qualitative assessment of the dike's resilience.

[0176] Based on the same inventive concept, this invention provides a specific embodiment, whose toughness assessment process is as follows:

[0177] (1) Damage analysis: Collect basic data on the levee to be evaluated. Based on the characteristics of the levee construction materials, levee cross-section, geological conditions, wave parameters, and incoming flow direction, the levee is divided into two sections. A typical cross-section is shown below. Figure 2 As shown. Figure 2 Section 1 of the dike shown in (a) is a caisson-type vertical dike with a width B = 10m and a height h = 16.2m. The design wave conditions are a water depth d = 12.3m and an effective wave height H. s =3m, period T =7s, wavelength L =63.92m, wave direction angle β =0°, effective wave height in deep water H0 =3.286m, and length of the dike section l1 =120m. Figure 2 Section 2 of the embankment shown in (b) is a sloping embankment constructed of twisted I-shaped blocks, with a crest width B. t =10m, width of the dike base B b =65.2m, levee height h = 18.4m, design wave conditions are water depth d = 14.2m, significant wave height H s =3.5m, wavelength L =124.57m, average period T =11.4s, deep water effective wave height H0 =3.604m, dike section length l2 =80m.

[0178] Based on the basic failure modes proposed in this invention, and considering the history of dike failures and performance requirements, the influencing factors of the basic failure modes are determined using the following formula:

[0179]

[0180] for Figure 2 The influencing factors of vertical breakwater wave overtopping failure shown in Figure (a) The influencing factor for slip failure is 0.25. The influencing factor for boulder instability is 0.5. The influencing factor of foundation scour is 0. It is 0.25. For Figure 2 The influencing factors of wave overtopping failure of the sloping breakwater shown in (b) are as follows. The influencing factor of slip failure is 0.3. The influencing factor of boulder instability is 0. The influencing factor of foundation scour is 0.5. It is 0.2.

[0181] (2) Response analysis to obtain the levee response parameters for each basic failure mode. For Figure 2 The wave overtopping volume of the vertical breakwater shown in (a) is calculated using the following formula:

[0182]

[0183] In the formula, Q is the wave displacement, and g is the gravitational acceleration, taken as 9.80 m / s². 2 H s Where d is the effective wave height, d is the water depth, and R is the effective wave height. c For the superelevation of the levee crest, γ β This is a factor that reduces the amount of water overflowed.

[0184] Specifically, the superelevation of the embankment crest in this section is R. c =3.9m, wave direction angle β = 0° corresponding to wave overshoot reduction factor γ β =1.00. Therefore, the overtopping amount Q is calculated to be 0.022m. 3 / (m·s).

[0185] Calculation using physical models Figure 2 The slippage of the vertical breakwater shown in (a) is assumed to be 1000 waves in a single storm surge. Wave generation is performed based on the wave conditions corresponding to the cross section, and the results of 1000 physical model tests are obtained. The average value is taken as the slippage result, i.e., S = 0.05m.

[0186] The underlying soil of section one of the embankment has relatively fine particles, with a median particle size D. 50 Since the depth is 0.8mm, the maximum scouring depth can be calculated using the following formula:

[0187]

[0188] Substituting the wave conditions of levee section one, we can obtain Z. mf =0.678m, then the scour rate D = Z mf / Bm =0.678 / 10 = 6.78%.

[0189] for Figure 2 The overtopping volume of the sloping embankment shown in (b) is calculated using the following formula:

[0190]

[0191] In the formula, A is an empirical coefficient, and K A T is the influence coefficient of the facing structure. P R represents the spectral peak period, and m represents the slope coefficient. Specifically, the freeboard of the embankment crest in this section is R. c =4.2m, influence coefficient K of the facing structure corresponding to the twisted I-beam block A =0.4, the slope coefficient m is 1.5, therefore the empirical coefficient A is taken as 0.035, and the spectral peak period T P =1.21×T=13.794s, substituting into the wave condition, we get the overtopping amount Q=0.047m. 3 / (m·s).

[0192] for Figure 2 The sloping embankment shown in (b) has a wave breaking similarity parameter ξ. z Calculate according to the following formula:

[0193]

[0194] The slope toe α is 0.588 rad. Substituting the relevant parameters, we get ξ. z =5.07, indicating that the waves have not broken. The following formula is used to calculate the rock erosion index:

[0195]

[0196] In the formula, Δ is the relative density of the boulders. For section two of the embankment, Δ = 1.6 is taken, and the nominal diameter D of the boulders is taken as... n50 =1m, P is the structural permeability coefficient, taken as 0.5, N is the wave number, taken as 1000. Then the erosion index E of the boulders can be calculated. r =6.32.

[0197] Median particle size D of foundation sand in section 2 of the embankment 50 If the depth is 0.8 mm, then the maximum scour depth of the embankment slope is calculated by the following formula:

[0198]

[0199] In the formula, the maximum wave height H max =H 13％ +H R H 13％ For a wave height of 13% of the cumulative frequency, H R The height of the reflected wave is calculated using the following formula:

[0200]

[0201] In the formula, H R H represents wave reflectivity. I ρ is the incident wave height, which is related to the slope properties. α is the slope toe, L0 is the deep water wavelength, and H0 is the deep water wave height.

[0202] Substituting the wave conditions of levee section two, we can obtain H. 13％ =H S ÷1.6×1.61=3.522m, take the incident wave height as H 13％ For the riprap slope, take ρ = 0.4, slope toe α = 0.588 rad, and the deep-water wavelength and deep-water wave height associated with the incident wave are 202.70 m and 3.627 m respectively. Therefore, Z is obtained. mf =1.733m, for a trapezoidal cross section, the average embankment width B can be obtained. m = (B t +B b ) / 2=37.6m, then the scour rate D=Z mf / B m =1.733 / 37.6 = 4.61%.

[0203] (3) Vulnerability analysis, combining the response parameters obtained above with... Figure 3 By comparing the vulnerability curves corresponding to the basic failure modes shown, the damage levels and probability distributions of different failure modes of the embankment section are obtained as follows:

[0204] Section 1: When wave overtopping fails, P1 = 99.7%, P2 = 95.7%, P3 = 0.3%. At the point of slip failure, P1 = 6.6%, P2 = 0%, P3 = 0%. During foundation erosion, P1 = 84.5%, P2 = 19.9%, and P3 = 0%.

[0205] Section 2: When the wave overtopping failure occurs, P1 = 100%, P2 = 100%, P3 = 41.8%. When the rock becomes unstable, P1 = 100%, P2 = 94.9%, and P3 = 13.1%. During foundation erosion, P1 = 39.3%, P2 = 4.6%, and P3 = 0%.

[0206] (4) Loss analysis, combining basic data on the dikes and market economic conditions. Figure 4 , Figure 5 , Figure 6 The loss curves shown are used to optimize the casualty rate, economic loss rate, and repair efficiency for different damage levels. The results are as follows:

[0207] Over-wave failure: When damage level i = 1, When damage level i = 2, When damage level i = 3,

[0208] Slip failure: When damage level i = 1, When damage level i = 2, When damage level i = 3,

[0209] Rock instability: When damage level i = 1, When damage level i = 2, When damage level i = 3,

[0210] Foundation scour: When damage level i = 1, When damage level i = 2, When damage level i = 3,

[0211] (5) Comprehensive evaluation: According to the formula given in this invention, the loss results of embankment section one and embankment section two in terms of casualty rate, economic loss rate, and repair efficiency are calculated respectively:

[0212] C1 = 0.25 × (4% × 1 × 10) -5 +95.4% × 1 × 10 -4 +0.3% × 1 × 10 -3 )+0.5×(6.6%×1×10 -6 +0%×1×10 -5 +0%×1×10 -4 )+0.25×(64.6%×1×10 -5 +19.9% ​​× 1 × 10 -4 +0%×1×10 -3 ) = 3.1323 × 10 -5

[0213] E1=0.25×(4%×10%+95.4%×25%+0.3%×60%)+0.5×(6.6%×5%+0%×15%+0%×30%)+0.25×(64.6%×5%+19.9%×25%+0%×60%)=8.32375%

[0214] R1=0.25×(4%×5%+95.4%×10%+0.3%×30%)+0.5×(6.6%×5%+0%×15%+0%×30%)+0.25×(64.6%×10%+19.9%×30%+0%×70%)=5.73%

[0215] C2 = 0.3 × (0% × 1 × 10) -5 +58.2% × 1 × 10 -4 +41.8% × 1 × 10 -3 )+0.5×(5.1%×1×10 -6 +81.8% × 1 × 10 -5 +13.1% × 1 × 10 -4 )+0.2×(34.7%×1×10 -5 +4.6% × 1 × 10 -4 +0%×1×10 -3 ) = 1.551395 × 10 -4

[0216] E2=0.3×(0%×10%+58.2%×25%+41.8%×60%)+0.5×(5.1%×5%+81.8%×10%+13.1%×20%)+0.2×(34.7%×5%+4.6%×25%+0%×60%)=17.9935%

[0217] R2=0.3×(0%×5%+58.2%×10%+41.8%×30%)+0.5×(5.1%×5%+81.8%×15%+13.1%×30%)+0.2×(34.7%×10%+4.6%×30%+0%×70%)=14.7055%

[0218] Therefore, the safety assessment index SA for the levee section k for:

[0219] SA1 = C1 = 3.1323 × 10 -5 SA2 = C2 = 1.551395 × 10 -4

[0220] Choose the economic loss rate decision ratio f E The repair efficiency decision ratio is 0.6, f. Ris 0.4, then the embankment section repair assessment index RA k is:

[0221] RA1=0.6×E1+0.4×R1=7.28625%, RA2=0.6×E2+0.4×R2=16.6783%

[0222] The overall embankment safety assessment index SA and the overall repair assessment index RA are calculated by weighting according to the length of each embankment section, as follows:

[0223]

[0224]

[0225] According to the qualitative evaluation criteria proposed by the present invention, since SA≤1×10 -4 and 10%<RA≤30%, the overall resilience level of this embankment is grade 3.

[0226] The specific embodiments of the present invention are described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essential content of the present invention. The above preferred features can be used in any arbitrary combination on the premise of no mutual conflict.

Claims

1. A method for evaluating the overall toughness of levees based on multiple failure modes, characterized in that, include: Collect basic data on the dikes, divide the dikes into several sections based on typical cross sections, assess the importance of the basic failure modes of each section, and obtain the influencing factors. Obtain the levee response parameters for each levee segment under different basic failure modes under a given wave; By comparing the levee response parameters with the vulnerability curves corresponding to the basic failure modes, the damage levels and probability distributions of different failure modes of the levee section are obtained. The analysis focuses on the losses caused by different damage levels from three dimensions: casualty rate, economic loss rate, and repair efficiency. Based on the influencing factors, the levee response parameters, the losses and probability distribution caused by different damage levels, the casualty rate, the economic loss rate, and the repair efficiency, the levee section safety assessment index and the levee section repair assessment index are calculated. The overall assessment index is formed by combining the safety assessment index and the repair index of all levee sections to conduct a qualitative assessment of the levee resilience. The basic information about the dikes includes information that affects the performance of the dikes, such as historical disaster information, meteorological and hydrological data, engineering topography and geology, dike construction materials, geometric dimensions and cross-sectional type. The process of dividing the dike into several sections based on typical cross-sections involves determining whether each section shares the same typical cross-section. The principle for determining whether a section shares the same typical cross-section is as follows: For the same type of embankment construction material, the variation in material parameters shall not exceed 5%; The cross-sectional shapes of the dikes are the same, and the variation in cross-sectional geometric dimensions does not exceed 5%. The underlying foundation soil is of the same type, and the variation in its properties does not exceed 10%. The potential wave characteristics within the levee section should not vary by more than 5%. The basic failure modes include wave failure, slip failure, rock instability and foundation scour; The influencing factor refers to the assessment of the importance of the basic failure mode of the dike. This influencing factor is related to dike performance, dike failure mechanism, and basic dike data, and is calculated using the following formula: ； In the formula, For the influencing factor corresponding to failure mode j of levee segment k, This represents the total number of times the levee section k has been damaged in history. This represents the number of times destruction mode j occurs.

2. The method for evaluating the overall toughness of a levee based on multiple failure modes according to claim 1, characterized in that, The levee response parameters refer to the parameters that reflect the changes in levee performance when a certain failure mode occurs under wave action. The types of levee response parameters correspond to the basic failure modes: the levee response parameters corresponding to overtopping failure, slippage failure, rock instability and foundation scour are overtopping amount, slippage amount, rock erosion index and scour rate, respectively. The wave overtopping refers to the average unit width discharge of waves over the crest of the dike along its length, expressed as a parameter. Q It indicates that the unit is m. 3 / (m·s); The slippage refers to the horizontal displacement of the dike along its width under wave action, expressed as a parameter. S It indicates that the unit is meters (m). The rock erosion index is calculated by the following formula: ； In the formula, The erosion index of boulders is a dimensionless parameter. A The cross-sectional erosion area is expressed in m². 2 , D n50 The nominal diameter of the stone block is in meters (m). The scouring rate is calculated by the following formula: ； In the formula, D The erosion rate is a dimensionless parameter. Z mf Maximum scour depth, in meters (m). B m The average width of the embankment is expressed in meters. The dike response parameters are obtained through formulas, numerical models, physical models, or post-disaster field measurements.

3. The method for evaluating the overall toughness of a levee based on multiple failure modes according to claim 1, characterized in that, The vulnerability curve establishes the relationship between the levee response parameters and the actual damage state based on a critical threshold, where the critical threshold is the standard for classifying the levee damage state into different damage levels. The critical threshold refers to the dike response parameter corresponding to a certain extreme damage state, and is classified into levels according to the degree of impact; the vulnerability curve follows a log-normal distribution, and the median and log standard deviation corresponding to different damage levels of the basic failure mode are obtained based on the critical threshold.

4. The method for evaluating the overall toughness of a levee based on multiple failure modes according to claim 3, characterized in that, The step of comparing the levee response parameters with the vulnerability curves corresponding to the basic failure modes to obtain the damage levels and probability distributions of different failure modes of the levee section includes: The exceedance probabilities corresponding to the obtained levee response parameters are read from the vulnerability curves for different damage levels. The difference between the exceedance probabilities of the two lines is the probability of a certain damage level, calculated according to the following formula: ； In the formula, This refers to the type of levee response parameters. The levee response parameters obtained by levee segment k under failure mode j. Let i be the probability of damage level i given the levee response parameters when the damage mode is j. P i It is the exceedance probability read from the i-th level vulnerability curve. P i+1 It is the exceedance probability read on the i+1 level vulnerability curve; When i=0, take P 0=1, This represents the probability that the dike will not be damaged, when i=max. .

5. The method for evaluating the overall toughness of a levee based on multiple failure modes according to claim 1, characterized in that, The casualty rate, economic loss rate, and repair efficiency are performance indicators determined by the dike damage mode, and they exhibit a probability distribution as the damage level, economic cost, basic dike data, and dike scale change. Based on the performance indicators that present a probability distribution: casualty rate, economic loss rate, and repair efficiency, a loss curve corresponding to the basic damage mode of the dike is obtained. The loss curves follow a log-normal distribution, and each performance index corresponds to a different median and log standard deviation under different failure modes.

6. The method for evaluating the overall toughness of a levee based on multiple failure modes according to claim 1, characterized in that, The calculation of the embankment safety assessment index and the embankment repair assessment index includes: Calculate the loss results of embankment segment k in terms of casualty rate, economic loss rate, and repair efficiency. C k , E k , R k : ； ； ； The influencing factors for different failure modes j of embankment segment k. ~ Let the parameters be the levee response parameters for different failure modes j of levee segment k. , , The casualty rate, economic loss rate, and repair efficiency corresponding to different damage levels i under different damage modes j; Safety assessment indicators for embankment sections The loss outcome, determined by the casualty rate, is expressed by the following formula: ； Decision ratio based on economic loss rate and repair efficiency f E , f R Then the embankment repair assessment indicators for: ； In the formula, f E , f R These are the decision ratios for economic loss rate and repair efficiency, respectively, and there are parameters between them. f E + f R The relationship is equal to 1.

7. The method for evaluating the overall toughness of a levee based on multiple failure modes according to claim 6, characterized in that, The overall evaluation index, which synthesizes the results of all embankment sections, is used to qualitatively assess the resilience of the embankment, including: The safety assessment indicators of the embankment section and the aforementioned embankment repair assessment indicators Weighted calculations are performed to obtain the overall safety assessment index of the dike. and overall restoration assessment indicators The calculation formula is as follows: ； ； In the formula, Let k be the length of the embankment segment. This refers to the total length of the dike. The overall security assessment indicators and the overall repair assessment indicators The overall resilience level of the levee under wave action was quantitatively evaluated. The larger the levee, the weaker its ability to ensure safety. The larger the levee, the more difficult it is to repair after a disaster.

8. The method for evaluating the overall toughness of a levee based on multiple failure modes according to claim 7, characterized in that, The qualitative assessment of the dike resilience includes: The qualitative evaluation criteria are as follows: Level 1 toughness; Level 2 toughness; Level 3 toughness; Level 4 toughness; Level 5 toughness.

9. A multi-failure mode-based system for evaluating the overall resilience of a levee, used to implement the method described in claim 1, characterized in that, include: The damage analysis module collects basic data on the dike, divides the dike into several sections based on typical cross-sections, assesses the importance of the basic damage modes of each section, and obtains the influencing factors. The response analysis module obtains the levee response parameters for different basic failure modes of each levee segment under a given wave, based on formulas, numerical models, physical models, or post-disaster field measurements. The vulnerability analysis module compares the levee response parameters with the vulnerability curves corresponding to the basic failure modes to obtain the damage level and probability distribution of different failure modes of the levee section. The loss analysis module analyzes the losses caused by different damage levels from three dimensions: casualty rate, economic loss rate, and repair efficiency. The comprehensive evaluation module calculates the safety assessment index and the repair assessment index of the dike section based on the influencing factors, the dike response parameters, the losses and probability distribution caused by different damage levels, the casualty rate, the economic loss rate, and the repair efficiency. It then integrates all the safety assessment index and the repair assessment index of the dike section to form an overall assessment index, thereby qualitatively assessing the dike's resilience.

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