Evolutionary state recognition and early warning method for embankment piping failure based on potential observation

Abstract

The application discloses a kind of embankment piping failure evolution state identification and early warning method based on potential observation, first, the potential observation system of earth-rock embankment is laid out, potential measurement is implemented, and real-time potential increment is calculated;Then, the distribution characteristics and variation characteristics of the obtained real-time potential increment are analyzed, and the evolution state of the piping failure of earth-rock embankment is identified;Finally, the early warning system of piping failure of earth-rock embankment is constructed, and the identification result of piping failure evolution state is used to implement real-time early warning for piping failure of earth-rock embankment;It can efficiently and quickly realize real-time capture and real-time early warning for different evolution states of piping failure, thereby ensuring the safety of embankment, reducing disaster losses, and improving the dynamic detection and early warning capability of earth-rock embankment and the technical level of disaster prevention and reduction.

Description

Technical Field

[0001] This invention belongs to the field of detection technology for piping failure in earth-rock dams, specifically involving a method for identifying and warning of the evolution state of piping failure in dams based on potential observation. Background Technology

[0002] According to statistics from the Ministry of Water Resources, by the end of 2020, my country had built over 98,000 reservoirs of various types, of which approximately 92% were earth-rock dams. In addition, 328,000 kilometers of river embankments of grade 5 and above had been constructed. These earth-rock dams play a vital role in flood control, power generation, water supply, and irrigation, generating significant economic and social benefits. However, about 80% of the existing earth-rock dams and embankments were built between the 1950s and 1970s. Due to low engineering design standards, poor construction quality, long-term impacts from flora and fauna, and aging and neglect, most earth-rock dams suffer from varying degrees of seepage damage, which is particularly pronounced during high water levels in the flood season, endangering the structural stability of the dams and the lives and property of the general public. Piping, a typical form of seepage damage, is numerous, widespread, and highly destructive, easily causing localized subsidence, uneven settlement, and overall instability of the dam body. In severe cases, it can even lead to dam failure and breaches, thus becoming one of the main causes of earth-rock dam failures. According to incomplete statistics, among earth-rock dams built after 1950, dam failures induced by piping accounted for as high as 54%. Therefore, timely and effective detection of piping damage in earth-rock dams, obtaining relevant evolutionary information on piping damage, and implementing real-time early warning are of great practical significance for determining the degree of evolution of piping damage, guiding engineering emergency intervention, and preventing and mitigating the disaster risks caused by piping damage.

[0003] Because piping failure in earth-rock dams is highly concealed, current engineering practices mainly rely on geophysical exploration technology to carry out related detection work. Although existing methods can accurately diagnose the location and extent of existing piping channels after piping failure occurs in the dam, from the perspective of disaster prevention and mitigation, it is still a reactive response after the fact and cannot achieve proactive tracking, identification, and early warning of the degree and state of piping failure. Summary of the Invention

[0004] In view of this, the purpose of this invention is to overcome the defects in the prior art and provide a method for identifying and warning of the evolution state of piping failure in dams based on potential observation. By utilizing the potential distribution characteristics and variation law of earth-rock dams, this method can efficiently and quickly achieve real-time capture and real-time warning of different evolution states of piping failure, thereby ensuring dam safety, reducing disaster losses, and improving the dynamic detection and early warning capabilities of earth-rock dams as well as the level of disaster prevention and mitigation technology.

[0005] The present invention provides a method for identifying and warning of the evolution of piping failure in dams based on potential observation, comprising the following steps:

[0006] Step 1: Deploy a potential monitoring system for the earth-rock embankment, conduct potential measurements, and calculate real-time potential increments;

[0007] Step 2: Analyze the distribution and variation characteristics of the obtained real-time potential increments, and identify the evolution state of piping failure in earth-rock embankments;

[0008] Step 3: Construct an early warning system for piping failure in earth-rock dams, and use the identification results of piping failure evolution state to implement real-time early warning for piping failure in earth-rock dams.

[0009] Furthermore, step one includes the following steps:

[0010] Step 1.1: Starting from the intersection of the top of the earth-rock dam and the downstream slope, set a survey line L perpendicular to the dam axis along the upstream direction;

[0011] Step 1.2: Arrange j+1 electrodes at equal intervals along the survey line L, in the order of M0, M1, ..., M j-1 M j M0 is located at the end point on the downstream side of survey line L, M j The endpoint located on the upstream side of survey line L;

[0012] Step 1.3: Use electrode M0 on survey line L as power supply electrode A, and arrange power supply electrode B at the dam toe point. Power supply electrode B and survey line L are located on the same dam cross section. Power supply electrode A and power supply electrode B are connected to the positive and negative terminals of the power supply through wires, respectively.

[0013] Step 1.4: Connect electrodes M1 to M2 on the measuring line L. j As measuring electrodes, measuring electrode N is arranged on the top of the dam, and measuring electrode N is located on the perpendicular bisector of the measuring line L on the top surface of the dam; measuring electrodes M1~M j The measuring electrode N is connected to the potential measuring device via wires;

[0014] Step 1.5: The potential measuring device performs time-interval measurements on the earth-rock embankment, and uses the potential results obtained from each measurement to further calculate the real-time potential increment at each measuring point. The total number of measurements t ≥ 3

[0015] The real-time potential increment is the difference between the real-time measured potential at the measuring point and the potential at the same location when the earth-rock embankment structure is intact. The calculation model is as follows:

[0016]

[0017] In the formula: For the nth measurement, the measuring electrode M i Real-time potential increment at the location; For the nth measurement, the measuring electrode M i Real-time measured potential at the location; Electrode M is used for measuring when the dam structure is intact. i The electrical potential at the location.

[0018] Furthermore, in step two, starting from the third measurement, the real-time potential increments of each measuring point obtained from each measurement are used to compare the magnitude relationship between the real-time potential increments of any two adjacent measuring points, and the distribution characteristics of the real-time potential increments of all measuring points along the measuring line are obtained.

[0019] Simultaneously, by using the real-time potential increments of each measurement and the previous two measurements obtained at each measuring point, the magnitude relationship between the real-time potential increments of any measuring point in three consecutive measurements is compared to obtain the time variation characteristics of the real-time potential increment of any single measuring point; by using the distribution characteristics and time variation characteristics of the real-time potential increments obtained in each measurement along the measuring line, the evolution state of piping failure of earth-rock embankments can be identified in real time.

[0020] Furthermore, the criteria for real-time identification of the evolution of piping failure in earth-rock dams are as follows:

[0021] ① When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment had no piping failure;

[0022] ② When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment was experiencing piping failure and was in the initial stage;

[0023] ③ When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment had piping failure and was in a state of continuous development of piping channels;

[0024] ④ When the distribution characteristics of the survey line are And the time-varying characteristics are or At that time, it was determined that the earth-rock dam had piping failure and that the piping channel was about to penetrate the dam body;

[0025] ⑤ When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock dam had piping failure and that the piping channel had penetrated the dam body.

[0026] Furthermore, in step three, an early warning system is constructed: an early warning system for piping failure in earth-rock dams is constructed based on the degree of piping failure risk, the early warning level of piping failure, the early warning degree of piping failure, and the early warning signal of piping failure. Among them, the degree of piping failure risk includes five levels, in order of no risk, low risk, medium risk, high risk, and extremely high risk; the early warning level of piping failure includes four levels, in order of Level IV, Level III, Level II, and Level I; the early warning degree of piping failure includes four levels, in order of general, serious, particularly serious, and extremely serious; the early warning signal of piping failure includes four signals, in order of blue early warning signal of piping failure, yellow early warning signal of piping failure, orange early warning signal of piping failure, and red early warning signal of piping failure.

[0027] Furthermore, based on the constructed early warning system for piping failure of earth-rock dams, and utilizing the identification results of the piping failure evolution state of earth-rock dams obtained in step two, real-time early warning of piping failure of earth-rock dams is implemented. The specific early warning criteria are as follows:

[0028] ① When it is determined that there is no piping failure in the earth-rock embankment, the risk level of piping failure is determined to be no risk, and no piping failure warning is issued;

[0029] ② When piping failure is identified in an earth-rock embankment and it is in the initial stage, the danger level of piping failure is determined to be low, the early warning level of piping failure is assessed as Level IV, indicating a general warning level, and a blue early warning signal for piping failure is issued.

[0030] ③ When piping failure is identified in an earth-rock embankment and the piping channel is in a state of continuous development, the danger level of piping failure is determined to be medium danger, the early warning level of piping failure is assessed as Level III, indicating a serious warning level, and a yellow early warning signal for piping failure is issued;

[0031] ④ When piping failure is identified in an earth-rock dam and the piping channel is about to penetrate the dam body, the risk level of piping failure is determined to be high risk, the early warning level of piping failure is assessed as Level II, indicating a particularly serious warning level, and an orange early warning signal for piping failure is issued;

[0032] ⑤ When piping failure is identified in an earth-rock dam and the piping channel has penetrated the dam body, the danger level of the piping failure is determined to be extremely high, the early warning level of the piping failure is assessed as Level I, indicating an extremely serious warning level, and a red early warning signal for piping failure is issued.

[0033] Furthermore, in step 1.1, if the width of the dam crest is greater than one-fifth of the length of the downstream dam slope line perpendicular to the dam axis, then the length d of the survey line L is equal to one-fifth of the length of the downstream dam slope line perpendicular to the dam axis; if the width of the dam crest is less than or equal to one-fifth of the length of the downstream dam slope line perpendicular to the dam axis, then the length d of the survey line L is equal to the width of the dam crest.

[0034] Furthermore, in step 1.2, the number of electrodes arranged is not less than 4, and the distance between the electrodes is 0.5 to 1 meter. If the length d of the measuring line cannot meet the above two requirements at the same time, the distance between the electrodes should be appropriately reduced to prioritize meeting the requirement of the number of electrodes.

[0035] Furthermore, in step 1.3, the power supply is a DC power supply, and the current is not less than 5 amperes. Furthermore, in step 1.4, the distance between the measuring electrode N and the measuring line L is greater than or equal to 5d, and the minimum scale (accuracy) of the potential measuring device is not higher than 0.001 volts. This invention is based on the inventors' in-depth research and discovery of inherent physical laws: when piping failure occurs in an earth-rock dam, its internal seepage field undergoes drastic changes, mainly manifested in the formation and expansion of the piping channel altering the saturation of the soil and rock inside the dam body and the position of the phreatic line. The resistivity characteristics of the dam body medium are highly sensitive to its saturation; increased saturation leads to a significant decrease in resistivity. Therefore, after applying a stable artificial current field to the dam crest, the resistivity distribution change caused by piping evolution will manifest as a redistribution of surface potential. The potential increment ΔU defined in this invention, i.e., the difference between the real-time measured potential and the reference potential when the structure is intact, can effectively capture this abnormal signal caused by piping. By monitoring the spatial distribution characteristics of ΔU along the measuring line on the dam crest and its changes over time, the specific evolution stage of the piping can be inferred. Appendix Figure 2 The typical relationship curve between ΔU and the piping evolution process, verified by model experiments, is shown.

[0036] The beneficial effects of this invention are as follows: The method for identifying and warning of the evolution state of piping failure in embankments based on potential observation disclosed in this invention is convenient, fast, and highly operable. It can capture and determine in real time whether piping failure exists in earth-rock embankments and the evolution state of piping failure based on relevant potential characteristics, and realize real-time early warning of piping failure. It can not only be applied to the on-site diagnosis after piping failure occurs, providing a basis for decision-making for flood control, emergency rescue, and reinforcement of earth-rock embankments, but also to the long-term seepage monitoring and seepage stability evaluation of earth-rock embankments, guiding the daily operation and maintenance management of embankment projects. Attached Figure Description

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0038] Figure 1 This is a schematic diagram of the layout of the potential monitoring system for earth-rock dams in this invention;

[0039] Figure 2 This is a graph showing the relationship between the measured potential increment and the evolution process of piping failure in this invention;

[0040] Appendix Figure 1In the middle: 1. Earth-rock dam, 2. Water area in front of the dam, 3. Measuring electrode N, 4. Dam crest, 5. Measuring electrode M, 6. Measuring line layout, 7. Power supply electrode A, 8. Downstream slope of the dam, 9. Power supply connection wire, 10. Power supply electrode B, 11. Potential measuring device connection wire, 12. Potential measuring device. Detailed Implementation

[0041] Figure 1 This is a schematic diagram of the layout of the potential monitoring system for earth-rock dams in this invention; Figure 2 This is a graph showing the relationship between the measured potential increment and the evolution process of piping failure in this invention; as shown in the figure, Figure 2 As shown, the curves relating the potential increment (ΔU) measured through physical model experiments to the degree of piping development indicate that ΔU exhibits a regular variation with the development of piping: in the initial stage, ΔU remains constant from zero (horizontal segment), representing the piping-free stage; in the development stage, it continuously increases (uphill segment), reaching its peak value (peak point) just before the piping channel is about to be completed; subsequently, it begins to decrease (downhill segment), and after completion, it stabilizes at a new constant value (horizontal segment). The identification criteria of this invention are the refinement and application of this objective physical law; the method for identifying and warning of the evolution state of dam piping failure based on potential observation in this embodiment includes the following steps:

[0042] Step 1: Deploy a potential monitoring system for the earth-rock embankment, conduct potential measurements, and calculate real-time potential increments;

[0043] Step 2: Analyze the distribution and variation characteristics of the obtained real-time potential increments, and identify the evolution state of piping failure in earth-rock embankments;

[0044] Step 3: Construct an early warning system for piping failure in earth-rock dams, and use the identification results of piping failure evolution state to implement real-time early warning for piping failure in earth-rock dams;

[0045] Step one specifically includes:

[0046] 1. Starting from the intersection of the top of the earth-rock dam and the downstream slope, set a survey line L perpendicular to the dam axis along the upstream direction. If the width of the dam top is greater than one-fifth of the length of the downstream slope line perpendicular to the dam axis, then the length d of the survey line L is equal to one-fifth of the length of the downstream slope line perpendicular to the dam axis; if the width of the dam top is less than or equal to one-fifth of the length of the downstream slope line perpendicular to the dam axis, then the length d of the survey line L is equal to the width of the dam top.

[0047] 2. Arrange j+1 electrodes at equal intervals along the survey line L, namely M0, M1, ..., M j-1 M j M0 is located at the end point on the downstream side of survey line L, M jThe endpoint is located on the upstream side of the survey line L. The number of electrodes should be no less than 4, and the electrodes should be evenly spaced at a distance of 0.5 to 1 meter. If the length d of the survey line cannot meet both of the above requirements at the same time, the electrode spacing should be appropriately reduced to prioritize meeting the requirement for the number of electrodes.

[0048] 3. Use electrode M0 on survey line L as power supply electrode A, and place power supply electrode B at the dam toe point. Power supply electrode B and survey line L are located on the same dam cross section. Power supply electrode A and power supply electrode B are connected to the positive and negative terminals of the power supply respectively via wires. The power supply is a DC power supply with a current of not less than 5 amperes.

[0049] 4. Connect electrodes M1 to M2 on measuring line L. j Measuring electrodes M1 to M2 are used as measuring electrodes and are arranged on the dam crest. Measuring electrode N is located on the perpendicular bisector of the measuring line L, and the distance between measuring electrode N and measuring line L is greater than or equal to 5d. j The measuring electrode N is connected to the potential measuring device via wires. The minimum scale (accuracy) of the potential measuring device is no higher than 0.001 volts.

[0050] 5. Based on the above-mentioned dam crest survey line L and measuring electrodes M1 to M... j A potential observation system consists of measuring electrode N, power supply electrode A, power supply electrode B, power supply, potential measuring device, and connecting wires. Figure 1 As shown.

[0051] 6. Utilize the established potential monitoring system to perform sequential measurements on the earth-rock embankment at equal time intervals. Using the potential results obtained from each measurement, further calculate the real-time potential increment at each measuring point. The total number of measurements, t, is determined based on the measurement objective, t…3; the equal time interval between measurements should ideally be 1–3 minutes.

[0052] The real-time potential increment is the difference between the real-time measured potential at the measuring point and the potential at the same location when the earth-rock embankment structure is intact. The calculation model is as follows:

[0053] ΔU (Mi,n) =U (Mi,n) -U (Mi) (1≤i≤j, 1≤n≤t)

[0054] In the formula: For the nth measurement, the measuring electrode M i Real-time potential increment at the location; For the nth measurement, the measuring electrode M i Real-time measured potential at the location; Electrode M is used for measuring when the dam structure is intact. i The electrical potential at the location.

[0055] Step two specifically includes:

[0056] 1. Starting from the third measurement, using the real-time potential increments of each measuring point obtained from each measurement, compare the magnitude relationship between the real-time potential increments of any two adjacent measuring points to obtain the distribution characteristics of the real-time potential increments of all measuring points along the measuring line; at the same time, using the real-time potential increments of each measuring point obtained from each measurement and the previous two measurements, compare the magnitude relationship between the real-time potential increments of any measuring point in three consecutive measurements to obtain the change characteristics of the real-time potential increment of any single measuring point over time.

[0057] 2. Simultaneously, by utilizing the distribution characteristics and time-varying characteristics of the real-time potential increments obtained from each measurement along the survey line, the evolution state of piping failure in earth-rock embankments can be identified in real time. Figure 2 This diagram illustrates the relationship between the potential increment obtained through calculation and experimentation after the deployment of the potential observation system in this invention and the evolution process of piping failure in earth-rock embankments.

[0058] The evolution of piping failure in earth-rock dams includes both no piping failure and piping failure. The piping failure state includes four states, which are, according to the evolution process, the initial piping failure state, the continuous development of the piping channel, the piping channel about to penetrate the dam body, and the piping channel having penetrated the dam body.

[0059] The specific identification criteria are as follows:

[0060] ① When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment had no piping failure;

[0061] ② When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment was experiencing piping failure and was in the initial stage;

[0062] ③ When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment had piping failure and was in a state of continuous development of piping channels;

[0063] ④ When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock dam had piping failure and that the piping channel was about to penetrate the dam body;

[0064] ⑤ When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock dam had piping failure and that the piping channel had penetrated the dam body.

[0065] Step three specifically includes:

[0066] 1. Construct an early warning system for piping failure in earth-rock dams based on the degree of piping failure risk, the piping failure warning level, the piping failure warning severity, and the piping failure warning signal. The piping failure risk level includes five levels: no risk, low risk, medium risk, high risk, and extremely high risk. The piping failure warning level includes four levels: Level IV, Level III, Level II, and Level I. The piping failure warning severity includes four levels: general, serious, particularly serious, and extremely serious. The piping failure warning signal includes four signals: blue, yellow, orange, and red.

[0067] 2. Based on the constructed early warning system for piping failure of earth-rock dams, and utilizing the identification results of the piping failure evolution state of earth-rock dams obtained in step two, real-time early warning of piping failure of earth-rock dams is implemented. The specific early warning criteria are as follows:

[0068] ① When it is determined that there is no piping failure in the earth-rock embankment, the risk level of piping failure is determined to be no risk, and no piping failure warning is issued;

[0069] ② When piping failure is identified in an earth-rock embankment and it is in the initial stage, the danger level of piping failure is determined to be low, the early warning level of piping failure is assessed as Level IV, indicating a general warning level, and a blue early warning signal for piping failure is issued.

[0070] ③ When piping failure is identified in an earth-rock embankment and the piping channel is in a state of continuous development, the danger level of piping failure is determined to be medium danger, the early warning level of piping failure is assessed as Level III, indicating a serious warning level, and a yellow early warning signal for piping failure is issued;

[0071] ④ When piping failure is identified in an earth-rock dam and the piping channel is about to penetrate the dam body, the risk level of piping failure is determined to be high risk, the early warning level of piping failure is assessed as Level II, indicating a particularly serious warning level, and an orange early warning signal for piping failure is issued;

[0072] ⑤ When piping failure is identified in an earth-rock dam and the piping channel has penetrated the dam body, the danger level of the piping failure is determined to be extremely high, the early warning level of the piping failure is assessed as Level I, indicating an extremely serious warning level, and a red early warning signal for piping failure is issued.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for identifying and warning of the evolution of piping failure in dams based on potential observation, characterized in that: Includes the following steps: Step 1: Deploy a potential monitoring system for the earth-rock embankment, conduct potential measurements, and calculate real-time potential increments; Step 2: Analyze the distribution and variation characteristics of the obtained real-time potential increments, and identify the evolution state of piping failure in earth-rock embankments; Step 3: Construct an early warning system for piping failure in earth-rock dams, and use the identification results of piping failure evolution state to implement real-time early warning for piping failure in earth-rock dams; Step one includes the following steps: Step 1.1: Starting from the intersection of the top of the earth-rock dam and the downstream slope, set a survey line L perpendicular to the dam axis along the upstream direction; Step 1.2: Arrange j+1 electrodes at equal intervals along the survey line L, in the order of M0, M1, ..., M j-1 M j M0 is located at the end point on the downstream side of survey line L, M j The endpoint located on the upstream side of survey line L; Step 1.3: Use electrode M0 on survey line L as power supply electrode A, and arrange power supply electrode B at the dam toe point. Power supply electrode B and survey line L are located on the same dam cross section. Power supply electrode A and power supply electrode B are connected to the positive and negative terminals of the power supply through wires, respectively. Step 1.4: Connect electrodes M1 to M2 on the measuring line L. j As measuring electrodes, measuring electrode N is arranged on the top of the dam, and measuring electrode N is located on the perpendicular bisector of the measuring line L on the top surface of the dam; measuring electrodes M1~M j The measuring electrode N is connected to the potential measuring device via wires; Step 1.5: The potential measuring device measures the earth-rock embankment at equal intervals, and uses the potential results obtained from each measurement to further calculate the real-time potential increment at each measuring point. The total number of measurements t≥3. The real-time potential increment is the difference between the real-time measured potential at the measuring point and the potential at the same location when the earth-rock embankment structure is intact. The calculation model is as follows: In the formula: For the nth measurement, the measuring electrode M i Real-time potential increment at the location; For the nth measurement, the measuring electrode M i Real-time measured potential at the location; Electrode M is used to measure the dam structure when it is intact. i The potential at the location; in step two, starting from the third measurement, the real-time potential increment of each measuring point obtained from each measurement is used to compare the magnitude relationship between the real-time potential increments of any two adjacent measuring points, and to obtain the distribution characteristics of the real-time potential increments of all measuring points along the measuring line. Meanwhile, by using the real-time potential increments of each measurement and the previous two measurements obtained at each measuring point, the magnitude relationship between the real-time potential increments of any measuring point in three consecutive measurements is compared to obtain the time variation characteristics of the real-time potential increment of any single measuring point; by using the distribution characteristics and time variation characteristics of the real-time potential increments obtained in each measurement along the measuring line, the evolution state of piping failure of earth-rock embankments is identified in real time. The criteria for real-time identification of the evolution of piping failure in earth-rock dams are as follows: ① When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment had no piping failure; ② When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment was experiencing piping failure and was in the initial stage; ③ When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock embankment had piping failure and was in a state of continuous development of piping channels; ④ When the distribution characteristics of the survey line are And the time-varying characteristics are or At that time, it was determined that the earth-rock dam had piping failure and that the piping channel was about to penetrate the dam body; ⑤ When the distribution characteristics of the survey line are And the time-varying characteristics are At that time, it was determined that the earth-rock dam had piping failure and that the piping channel had penetrated the dam body.

2. The method for identifying and warning of the evolution state of dam piping failure based on potential observation according to claim 1, characterized in that: In step three, an early warning system is constructed: an early warning system for piping failure in earth-rock dams is constructed based on the degree of piping failure risk, the early warning level of piping failure, the early warning degree of piping failure, and the early warning signal of piping failure. Among them, the degree of piping failure risk includes five levels, in order of no risk, low risk, medium risk, high risk, and extremely high risk; the early warning level of piping failure includes four levels, in order of Level IV, Level III, Level II, and Level I; the early warning degree of piping failure includes four levels, in order of general, serious, particularly serious, and extremely serious; the early warning signal of piping failure includes four signals, in order of blue early warning signal, yellow early warning signal, orange early warning signal, and red early warning signal of piping failure.

3. The method for identifying and warning of the evolution state of dam piping failure based on potential observation according to claim 2, characterized in that: Based on the constructed early warning system for piping failure of earth-rock dams, the identification results of the piping failure evolution state of earth-rock dams obtained in step two are used to implement real-time early warning for piping failure of earth-rock dams. The specific early warning criteria are as follows: ① When it is determined that there is no piping failure in the earth-rock embankment, the risk level of piping failure is determined to be no risk, and no piping failure warning is issued; ② When piping failure is identified in an earth-rock embankment and it is in the initial stage, the danger level of piping failure is determined to be low, the early warning level of piping failure is assessed as Level IV, indicating a general warning level, and a blue early warning signal for piping failure is issued. ③ When piping failure is identified in an earth-rock embankment and the piping channel is in a state of continuous development, the danger level of piping failure is determined to be medium danger, the early warning level of piping failure is assessed as Level III, indicating a serious warning level, and a yellow early warning signal for piping failure is issued; ④ When piping failure is identified in an earth-rock dam and the piping channel is about to penetrate the dam body, the risk level of piping failure is determined to be high risk, the early warning level of piping failure is assessed as Level II, indicating a particularly serious warning level, and an orange early warning signal for piping failure is issued; ⑤ When piping failure is identified in an earth-rock dam and the piping channel has penetrated the dam body, the danger level of the piping failure is determined to be extremely high, the early warning level of the piping failure is assessed as Level I, indicating an extremely serious warning level, and a red early warning signal for piping failure is issued.

4. The method for identifying and warning of the evolution state of dam piping failure based on potential observation according to claim 1, characterized in that: In step 1.1, if the width of the dam crest is greater than one-fifth of the length of the downstream dam slope line perpendicular to the dam axis, then the length d of the survey line L is equal to one-fifth of the length of the downstream dam slope line perpendicular to the dam axis; if the width of the dam crest is less than or equal to one-fifth of the length of the downstream dam slope line perpendicular to the dam axis, then the length d of the survey line L is equal to the width of the dam crest.

5. The method for identifying and warning of the evolution state of dam piping failure based on potential observation according to claim 1, characterized in that: In step 1.2, the number of electrodes arranged shall not be less than 4, and the distance between the electrodes shall be 0.5 to 1 meter. If the length d of the measuring line cannot meet the above two requirements at the same time, the distance between the electrodes shall be appropriately reduced to prioritize meeting the requirement of the number of electrodes.

6. The method for identifying and warning of the evolution state of dam piping failure based on potential observation according to claim 1, characterized in that: In step 1.3, the power supply is a DC power supply with a current of not less than 5 amps.

7. The method for identifying and warning of the evolution state of dam piping failure based on potential observation according to claim 1, characterized in that: In step 1.4, the distance between the measuring electrode N and the measuring line L is greater than or equal to 5d, and the minimum scale (accuracy) of the potential measuring device is not higher than 0.001 volts.

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