Dam abutment slope structure health monitoring system and method based on distributed strain optical cables

Abstract

The invention discloses a dam abutment slope structure health monitoring system and method based on distributed strain optical cables. Comprising the following steps: obtaining zero strain data of each distributed measuring point of the dam abutment slope by subtracting initial stable strain data of each distributed measuring point of the dam abutment slope from initial stable temperature data of the corresponding distributed measuring point of the dam abutment slope; obtaining real-time strain data of each distributed measuring point of the dam abutment slope by subtracting the strain data at each moment of each distributed measuring point of the dam abutment slope from the temperature data at the corresponding moment of each distributed measuring point corresponding to the dam abutment slope; performing strain calculation according to the real-time strain data of each distributed measuring point of the dam abutment slope and the zero strain data of the corresponding distributed measuring point of the dam abutment slope to obtain the strain variation of each distributed measuring point of the dam abutment slope along with the time change; and evaluating the structural health state of the dam abutment slope according to the development trend of the strain variation of each distributed measuring point of the dam abutment slope along with the time change and a preset periodic environment interference curve.

Description

Technical Field

[0001] This invention relates to the field of dam safety monitoring, specifically to a dam abutment slope structure health monitoring system and method based on distributed strain optical cables. Background Technology

[0002] As a critical infrastructure, the safe operation of dams directly impacts the safety of life and property downstream and regional economic stability. The stability of the dam abutment slopes is a crucial component of the overall dam safety. In practical engineering, many large-scale water conservancy projects are constructed in deeply incised V-shaped valleys. This geological environment often results in significant differences in geological conditions and topographic slopes on both sides of the dam. The main body of the dam is typically an inverted trapezoidal structure. Under the immense weight of its own body and water pressure, its gravitational component generates uneven stress on both dam abutments. Specifically, due to gravity and the characteristics of the dam structure, the dam as a whole tends to tilt and compress towards the side with the gentler slope of the abutment. This causes the gentler slope to bear greater compressive stress, resulting in greater compressive strain in the rock mass of that area, making it prone to deformation and cracking over long-term. While the stress on the steeper slope is relatively smaller, the asymmetrical tilting tendency of the dam as a whole leads to differential deformation at the junction of the dam and the rock mass of that side, also making it susceptible to structural cracking. Once cracks form and expand, they can easily become dominant channels for reservoir water seepage. The seepage pressure of the water flow and its softening effect on the rock will further exacerbate the development of cracks, seriously threatening the long-term service safety of the dam.

[0003] Currently, monitoring methods for dam abutment slopes are mainly divided into two categories: surface monitoring and internal monitoring. Surface monitoring primarily employs geodetic methods such as total stations and GPS / GNSS. These methods can only acquire surface displacement information and cannot detect the stress state, deformation evolution, and seepage conditions of the left and right abutment slopes and the dam's contact surface. Furthermore, they are susceptible to adverse weather conditions such as rain and fog. Internal monitoring mainly relies on drilling holes in the rock mass at the contact surface between the two banks and deploying sensors such as inclinometers and multi-point displacement gauges within these holes. While these point sensors can provide high-precision data at specific locations, their spatial coverage is limited. They cannot acquire continuous strain distribution along a certain path and struggle to accurately capture the initial initiation location and subsequent propagation path of deformation and cracks. Especially in stress concentration areas, the omission of monitoring points can potentially lead to the overlooking of significant safety hazards.

[0004] Therefore, there is an urgent need for a new continuous real-time monitoring method for dam shoulder slopes that can overcome the limitations of existing surface monitoring ("blind spots") and traditional internal monitoring ("point-based") methods. Summary of the Invention

[0005] The purpose of this invention is twofold: firstly, to provide a dam abutment slope structural health monitoring system based on distributed strain optical cables; and secondly, to provide a method for monitoring the structural health of dam abutment slopes based on distributed strain optical cables. This system and method enable direct, in-situ monitoring of this vulnerable structural interface by deploying distributed strain and temperature optical cables along the stress concentration zone and structurally vulnerable surface at the interface between the slopes on both banks and the dam. This effectively solves the problem that existing surface monitoring methods cannot perceive the internal state. By employing a large-area deployment of distributed sensing optical cables along the dam abutment slope, discrete "measuring points" are upgraded to continuous "measuring lines" and "measuring surfaces," achieving blind-spot-free, high-density, full-coverage monitoring of the dam abutment slope. This allows for the detection of problems easily missed by traditional methods, such as localized stress concentrations and early-stage minute deformations.

[0006] To achieve this objective, the present invention provides a dam abutment slope structure health monitoring system based on distributed strain optical cables, comprising: The strain and temperature data of each distributed measuring point on the dam abutment slope are monitored in real time by using distributed strain sensing optical cables and distributed temperature sensing optical cables arranged according to a preset path on the dam abutment slope. In the initial stable state of the dam abutment slope, the zero-point strain data of each distributed measuring point on the dam abutment slope is obtained by subtracting the initial stable strain data from the initial stable temperature data of the corresponding distributed measuring points on the dam abutment slope. Furthermore, in each moment after the initial stable state of the dam abutment slope, the real-time strain data of each distributed measuring point on the dam abutment slope is obtained by subtracting the strain data of each distributed measuring point on the dam abutment slope from the corresponding temperature data of the corresponding distributed measuring points on the dam abutment slope. Based on the real-time strain data of each distributed measuring point on the dam abutment slope and the zero-point strain data of the corresponding distributed measuring points on the dam abutment slope, strain calculation is performed to obtain the strain change of each distributed measuring point on the dam abutment slope over time. The structural health status of the dam abutment slope is assessed based on the development trend of strain changes over time at various distributed measuring points on the slope and the preset periodic environmental disturbance curves.

[0007] Furthermore, the distributed strain sensing optical cable and the distributed temperature sensing optical cable are laid along an S-shaped path from low to high on the dam shoulder slope, and the turning points of the distributed strain sensing optical cable and the distributed temperature sensing optical cable along the S-shaped path are fixed to the edge of the dam shoulder slope.

[0008] Furthermore, the process of deploying distributed strain sensing optical cables and distributed temperature sensing optical cables according to the set route is as follows: During the layered pouring of concrete on the dam shoulder slope, the distributed strain sensing optical cables and distributed temperature sensing optical cables are fixed in advance along an S-shaped path on the surface of the rock mass on the hillside where the dam shoulder slope is located. The part of the dam shoulder slope above the ground plane is divided into multiple segments from low to high and concrete is poured in segments from low to high. During the concrete pouring process, the flowing concrete automatically covers the distributed strain sensing optical cables and distributed temperature sensing optical cables. After the concrete solidifies, the distributed strain sensing optical cables and distributed temperature sensing optical cables are fixed.

[0009] Furthermore, the initial stability strain data of each distributed measuring point on the dam abutment slope and the initial stability temperature data of the corresponding distributed measuring points on the dam abutment slope are obtained after the dam abutment slope is poured and the structure is stable.

[0010] Furthermore, the method for calculating the strain change of each distributed measuring point on the dam abutment slope over time by using real-time strain data from each distributed measuring point and zero-point strain data from the corresponding distributed measuring points on the dam abutment slope includes: subtracting the real-time strain data values ​​from the corresponding zero-point strain data values ​​of each distributed measuring point on the dam abutment slope point by point to obtain the strain change of each distributed measuring point on the dam abutment slope over time. ,in, For the m-th distributed measuring point on the dam abutment slope The change in strain at any given time. For the m-th distributed measuring point on the dam abutment slope Real-time strain data values ​​at any given moment. This represents the zero-point strain data value corresponding to the m-th distributed measuring point on the dam abutment slope. Let m be the spatial coordinates of the distributed measuring point. This refers to the nth monitoring time.

[0011] Furthermore, the method for assessing the structural health status of the dam abutment slope based on the development trend of strain changes over time at various distributed measuring points on the dam abutment slope and a preset periodic environmental disturbance curve includes: within a preset series of sliding time windows, when the variance of strain changes over time at various distributed measuring points on the dam abutment slope is less than a first preset threshold, the dam abutment slope structure is assessed to be in a stable state; or when the cross-correlation coefficient between strain changes over time at various distributed measuring points on the abutment slope and the preset periodic environmental disturbance curve is greater than a second preset threshold, it is determined that strain changes over time at various distributed measuring points on the abutment slope fluctuate periodically with environmental factors, exhibiting a convergent or periodic trend, and the dam abutment slope structure is assessed to be in a stable state.

[0012] Furthermore, when the strain change of each distributed measuring point on the dam abutment slope over time exhibits a monotonically increasing or monotonically decreasing trend over multiple consecutive monitoring periods, the residual signal between the strain change of each distributed measuring point on the dam abutment slope over time and the environmental interference component at the corresponding time point in the preset periodic environmental interference curve is calculated. When the residual signal is less than a third preset threshold over multiple consecutive detection periods, it is assessed that the dam abutment slope structure is in a stable state; otherwise, it is assessed that the dam abutment slope structure is undergoing plastic deformation or long-term creep and is in a state of structural deterioration.

[0013] Furthermore, when the strain change of each distributed measuring point on the dam abutment slope over time shows a peak amplitude exceeding the safety threshold at a single location point on the distributed strain sensing optical cable, it is determined that a crack has appeared at that single location point. The location of the crack is located based on the position of the single location point on the distributed strain sensing optical cable for subsequent repair.

[0014] Furthermore, a method for monitoring the structural health of dam abutment slopes based on the system using distributed strain optical cables includes: The strain and temperature data of each distributed measuring point on the dam abutment slope are monitored in real time by using distributed strain sensing optical cables and distributed temperature sensing optical cables arranged according to a preset path on the dam abutment slope. In the initial stable state of the dam abutment slope, the zero-point strain data of each distributed measuring point on the dam abutment slope is obtained by subtracting the initial stable strain data from the initial stable temperature data of the corresponding distributed measuring points on the dam abutment slope. Furthermore, in each moment after the initial stable state of the dam abutment slope, the real-time strain data of each distributed measuring point on the dam abutment slope is obtained by subtracting the strain data of each distributed measuring point on the dam abutment slope from the corresponding temperature data of the corresponding distributed measuring points on the dam abutment slope. Based on the real-time strain data of each distributed measuring point on the dam abutment slope and the zero-point strain data of the corresponding distributed measuring points on the dam abutment slope, strain calculation is performed to obtain the strain change of each distributed measuring point on the dam abutment slope over time. The structural health status of the dam abutment slope is assessed based on the development trend of strain changes over time at various distributed measuring points on the slope and the preset periodic environmental disturbance curves.

[0015] The beneficial effects of this invention are as follows: This invention proposes a construction method that involves layered pouring and simultaneous segmented fixing of the dam concrete. It cleverly utilizes the existing construction process of the dam body to permanently and securely embed the sensing optical cable between the dam concrete and the abutment rock. This method not only fundamentally solves the construction problem of directly bonding and fixing the sensing optical cable to rough and hard rock surfaces, but also protects the sensor from damage caused by exposure, thereby greatly improving the coordinated deformation capability of the monitoring system and the dam structure, and enhancing its long-term service survival rate.

[0016] This invention upgrades traditional point-based monitoring to continuous monitoring along lines and even across surfaces by deploying sensing optical cables in an S-shaped path. This distributed, full-coverage monitoring method overcomes the limitations of traditional internal monitoring (such as inclinometers and multi-point displacement gauges) in terms of limited layout density and numerous blind spots. It can comprehensively cover the critical interface between the dam body and the abutment rock mass, ensuring that local stress concentrations or early micro-cracks at any location can be effectively detected.

[0017] This invention can accurately locate the initiation point of cracks by detecting abnormal strain peaks, and can further estimate the opening and closing width of cracks and dynamically track their development. This elevates dam stress monitoring from the traditional method of identifying potential hazards to the level of quantitative assessment and dynamic tracking, enabling dual early warning based on crack width and development rate, and providing more refined and timely decision-making basis for dam safety assessment. Attached Figure Description

[0018] Figure 1 This is a frontal view of the dam and the slopes of the dam shoulders on both banks according to the present invention; Figure 2 This is a schematic diagram of the deployment of the distributed sensing optical cable of the present invention; Figure 3 This is a schematic diagram showing the connection between the distributed strain sensing (DSS) optical cable and the distributed temperature sensing (DTS) optical cable and the demodulation instrument of the present invention. Figure 4 This is a schematic diagram of the structure of the present invention; Among them, 1—left dam shoulder slope; 2—right dam shoulder slope; 3—dam; 4—composite sensing optical cable; 5—distributed strain sensing (DSS) optical cable in composite sensing optical cable; 6—distributed temperature sensing (DTS) optical cable in composite sensing optical cable; 7—demodulation instrument. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1 like Figure 4 As shown, a dam abutment slope structure health monitoring system based on distributed strain optical cable includes: The data monitoring module is used to monitor the strain and temperature data of each distributed measuring point on the dam abutment slope in real time using distributed strain sensing optical cables and distributed temperature sensing optical cables arranged according to a preset path on the dam abutment slope. The data correction module is used to obtain the zero-point strain data of each distributed measuring point on the dam abutment slope by subtracting the initial stable strain data of each distributed measuring point on the dam abutment slope from the initial stable temperature data of the corresponding distributed measuring points on the dam abutment slope under the initial stable state; it is also used to obtain the real-time strain data of each distributed measuring point on the dam abutment slope by subtracting the strain data of each distributed measuring point on the dam abutment slope from the corresponding temperature data of the corresponding distributed measuring points on the dam abutment slope at each time after the initial stable state; and to calculate the strain change of each distributed measuring point on the dam abutment slope over time by performing strain calculation based on the real-time strain data of each distributed measuring point on the dam abutment slope and the zero-point strain data of the corresponding distributed measuring points on the dam abutment slope. The data analysis module is used to assess the structural health status of the dam abutment slope based on the development trend of strain changes over time at various distributed measuring points on the dam abutment slope and the preset periodic environmental disturbance curves.

[0021] Figure 1 This is a frontal view of the dam and the slopes on both sides of the dam. The main body of the dam 3 is an inverted trapezoidal structure. The two sides of the main body of the dam are the left slope 1 and the right slope 2, which are used to support the main body of the dam.

[0022] In some technical solutions, the distributed strain sensing optical cable and the distributed temperature sensing optical cable are laid along an S-shaped path from low to high on the dam shoulder slope, and the turning points of the distributed strain sensing optical cable and the distributed temperature sensing optical cable along the S-shaped path are fixed at the edge of the dam shoulder slope.

[0023] Distributed sensor optical cables were laid in an S-shaped path on the rock mass of the left and right abutment slopes of the dam. This S-shaped layout aims to maximize the spatial coverage of the monitoring area through path optimization of the sensor optical cables, ensuring that any local strain concentration or cracks that occur at any location can be effectively captured by the sensor network.

[0024] Figure 2 This is a schematic diagram of the layout of distributed strain sensing (DSS) optical cable 5 and distributed temperature sensing (DTS) optical cable 6. The distributed strain sensing optical cable and the distributed temperature sensing optical cable are hinged together or laid side by side to obtain the composite sensing optical cable 4.

[0025] In some technical solutions, the process of deploying distributed strain sensing optical cables and distributed temperature sensing optical cables according to a set route is as follows: During the layered pouring of concrete on the dam shoulder slope, the distributed strain sensing optical cables and distributed temperature sensing optical cables are fixed in advance along an S-shaped path on the surface of the rock mass on the hillside where the dam shoulder slope is located. The part of the dam shoulder slope above the ground plane is divided into multiple segments from low to high, and concrete is poured in segments from low to high. During the concrete pouring process, the flowing concrete automatically covers the distributed strain sensing optical cables and distributed temperature sensing optical cables. After the concrete solidifies, the distributed strain sensing optical cables and distributed temperature sensing optical cables are fixed.

[0026] In some embodiments, because the rock surface of the dam abutment slope is typically rough and hard, it is difficult to directly and firmly adhere the sensing optical cables (including distributed strain sensing optical cables and distributed temperature sensing optical cables). Therefore, this invention employs a construction method of laying and fixing the cables layer by layer and step by step during the dam concrete construction. The concrete dam body is typically poured in layers and blocks, layer by layer upwards. This invention utilizes this construction characteristic, synchronizing the laying of the sensing optical cables with the dam pouring progress. The specific operation is as follows: When the main dam construction is about to begin pouring a certain elevation layer, the construction workers first lay the sensing optical cable of that section on the dam shoulder slope rock surface at the corresponding elevation that will be in contact with the concrete layer, following a pre-designed S-shaped path. To prevent the fiber optic cable from shifting or being damaged by the impact of subsequent concrete pouring, adhesive, clips, and small anchors can be used to temporarily fix this section of cable to the designed path on the rock surface. After the fiber optic cable is laid and temporarily fixed, the concrete pouring work begins according to the normal procedure. The flowing concrete will naturally cover this section of sensing fiber optic cable, and after final solidification, it will be permanently and firmly embedded between the interface between the dam concrete and the dam abutment rock.

[0027] As the dam was poured layer by layer, the sensing optical cables were also laid upwards in a layered and segmented manner along an S-shaped path, eventually forming a distributed sensing network that completely covered the key contact surfaces of the dam abutment slopes from bottom to top. Through this method of layered pouring and simultaneous segmented fixing along with the dam, the sensing optical cables were finally firmly embedded in the contact surfaces between the dam and the dam abutment slopes.

[0028] After the sensing optical cables are laid out and fixed according to the above scheme, the ends of the distributed strain sensing (DSS) and distributed temperature sensing (DTS) optical cables in the composite sensing optical cable are connected to the demodulation instrument. For example... Figure 3 As shown, the distributed strain sensing (DSS) optical cable 5 and the distributed temperature sensing (DTS) optical cable 6 are connected to the demodulation instrument 7.

[0029] The initial stability strain data and the initial stability temperature data of the corresponding distributed measuring points on the dam abutment slope were obtained after the dam abutment slope was poured and the structure was stabilized.

[0030] After successful integration between the sensing optical cable and the demodulation instrument, the structurally stable state (initial stable state) after the dam's pouring is selected. Under this state, the demodulation instrument receives the initial stable temperature data from the distributed temperature sensing optical cable and the initial stable strain data from the distributed strain sensing optical cable. The initial stable temperature data is used to correct the initial stable strain data measured by the distributed strain sensing (DSS) optical cable to eliminate non-structural strain caused by temperature changes, thus obtaining the true mechanical strain purely caused by structural stress. This strain data is then stored as zero-point data.

[0031] The total strain measured by the distributed strain sensing optical cable contains two components: one is the mechanical strain generated by the actual stress on the structure (the target signal to be monitored), and the other is the thermal strain caused by the thermal expansion and contraction of the optical cable itself due to changes in ambient temperature (interference signal to be eliminated). By performing temperature compensation correction on the real-time strain data, the influence of temperature changes on strain monitoring can be effectively separated and eliminated from the total strain. This allows for the acquisition of true mechanical strain data purely caused by the stress on the dam abutment slope structure. It improves the accuracy and reliability of strain monitoring data, avoiding data distortion and misjudgment caused by diurnal or seasonal temperature fluctuations.

[0032] In some technical solutions, the method of calculating the strain change of each distributed measuring point on the dam abutment slope over time by using real-time strain data from each distributed measuring point on the dam abutment slope and zero-point strain data from the corresponding distributed measuring points includes: subtracting the real-time strain data values ​​from the corresponding zero-point strain data values ​​of each distributed measuring point on the dam abutment slope point by point to obtain the strain change of each distributed measuring point on the dam abutment slope over time. ,in, For the m-th distributed measuring point on the dam abutment slope The change in strain at any given time. For the m-th distributed measuring point on the dam abutment slope Real-time strain data values ​​at any given moment. This represents the zero-point strain data value corresponding to the m-th distributed measuring point on the dam abutment slope. Let m be the spatial coordinates of the distributed measuring point. This refers to the nth monitoring time.

[0033] By subtracting the temperature-compensated real-time strain data from the zero-point strain data point by point, non-structural strain caused by temperature changes can be eliminated, thus obtaining the true mechanical strain purely caused by structural stress. This allows for the extraction of the dynamic strain increment generated purely by changes in structural stress since the initial monitoring moment. This enables the quantitative tracking of the evolution of the dam abutment slope structural behavior, allowing any minute or local strain changes to be captured with high sensitivity.

[0034] The strain increments on the dam abutment slopes were continuously tracked, and their trends over time were analyzed. This trend analysis allows for assessment of the structural stability: if the strain change stabilizes after an initial increase, or fluctuates periodically only with factors such as reservoir water level (i.e., exhibiting a convergent or periodic trend), the structure is in a stable state. Conversely, if the strain change continues to show a sustained, irreversible, unidirectional cumulative increase after excluding periodic disturbances (i.e., exhibiting a developmental trend), the structure may be undergoing plastic deformation or long-term creep, indicating structural deterioration.

[0035] In some technical solutions, the method for assessing the structural health status of a dam abutment slope based on the development trend of strain changes over time at various distributed measuring points and a preset periodic environmental disturbance curve includes: within a preset series of sliding time windows, when the variance of strain changes over time at various distributed measuring points on the dam abutment slope is less than a first preset threshold, the dam abutment slope structure is assessed as being in a stable state; within a preset series of sliding time windows, when the variance of strain changes over time at various distributed measuring points on the dam abutment slope is greater than or equal to the first preset threshold, the dam abutment slope structure is assessed as being in an unstable state; or when the variance of strain changes over time at various distributed measuring points on the .... When the cross-correlation coefficient between the strain change over time and the preset periodic environmental disturbance curve is greater than the second preset threshold, it is determined that the strain change of each distributed measuring point on the shoulder slope fluctuates periodically with environmental factors (exhibiting a convergent or periodic trend), and the assessment indicates that the dam shoulder slope structure is in a stable state. When the cross-correlation coefficient between the strain change of each distributed measuring point on the shoulder slope over time and the preset periodic environmental disturbance curve is less than or equal to the second preset threshold, it is determined that the strain change of each distributed measuring point on the shoulder slope does not fluctuate periodically with environmental factors (non-convergent or periodic), and the assessment indicates that the dam shoulder slope structure is in an unstable state. The preset multiple consecutive sliding time windows include, but are not limited to, 15 days, and can be specifically designed according to actual conditions.

[0036] variance( The calculation formula is: ,in, It is the total number of data points within the sliding time window. It is a moment The change in strain. It is the sample mean of the strain change over time at various distributed measuring points on the dam abutment slope within the same time window. .

[0037] For the strain change sequence within the same time period and the periodic environmental interference sequence in the preset periodic environmental interference curve The formula for calculating the Pearson cross-correlation coefficient R between them is: n is the number of synchronized data point pairs within the calculation window. The mean of the strain change sequence within the calculation window. The value of the periodic environmental disturbance sequence within the calculation window is the mean. The correlation coefficient R ranges from -1 to 1. When R is close to +1, it indicates a strong positive linear correlation (the trends of change are completely in the same direction and synchronous). When R is close to -1, it indicates a strong negative linear correlation (the trends of change are completely opposite). When R is close to 0, it indicates no linear correlation between the two. The second preset threshold includes, but is not limited to, 0.7 or 0.8. In some embodiments, the data of the preset periodic environmental disturbance curve is obtained from continuous automatic monitoring of specific environmental parameters or authoritative historical databases. For example, the reservoir water level disturbance sequence is obtained by real-time and continuous monitoring of water level gauges (such as pressure water level gauges or radar water level gauges) deployed in the reservoir to obtain daily or higher frequency water level data. Reservoir water levels generally exhibit annual periodic changes (water level rises during the rainy season and falls during the dry season) or multi-year periodic changes (such as multi-year regulating reservoirs).

[0038] The stabilization of strain change after an initial increase indicates that the dam abutment slope structure has completed the initial stress redistribution and reached a new equilibrium after bearing load. The stabilization of strain change after an initial increase, or its periodic fluctuations with environmental factors, exhibiting a convergent or periodic trend, indicates that the dam abutment slope structure has an elastic and recoverable response to known environmental factors (such as periodic rises and falls in reservoir water levels). Assessing the stability of the dam abutment slope by judging whether the strain change exhibits a convergent or periodic trend allows for effective identification of the structural condition from long-term monitoring data, reducing the misjudgment rate.

[0039] In some technical solutions, when the strain change of each distributed measuring point on the dam abutment slope over time shows a monotonically increasing or monotonically decreasing trend over multiple consecutive monitoring periods, the residual signal between the strain change of each distributed measuring point on the dam abutment slope over time and the environmental interference component at the corresponding time point in the preset periodic environmental interference curve is calculated. When the residual signal is less than a third preset threshold over multiple consecutive detection periods, it is assessed that the dam abutment slope structure is in a stable state. When the residual signal is greater than or equal to the third preset threshold over multiple consecutive detection periods, it is assessed that the dam abutment slope structure is undergoing plastic deformation or long-term creep and is in a state of structural deterioration.

[0040] In some embodiments, when calculating the residual signal between the strain change of each distributed measuring point on the dam abutment slope over time and the environmental disturbance component at the corresponding time point in the preset periodic environmental disturbance curve, the environmental disturbance component corresponding to the current reservoir water level (the strain change corresponding to the current reservoir water level) is predicted based on a pre-established water level-strain response model (i.e., the linear relationship between the strain change corresponding to the periodic changes in historical reservoir water level data). This component is the theoretical elastic strain value caused by the change in reservoir water level load. The residual strain signal is obtained by subtracting the environmental disturbance component from the strain change of each distributed measuring point on the dam abutment slope over time. The third preset threshold includes, but is not limited to, 20µε~30µε (micro-strain). By comparing and analyzing the developmental strain trend curve with the periodic environmental disturbance curve, the aim is to distinguish between the elastic strain response caused by known environmental factors (such as periodic rises and falls in reservoir water level and temperature cycles) and the irreversible plastic deformation caused by the accumulation of structural damage. This improves the accuracy and reliability of the health status assessment of dam abutment slope structures and effectively avoids misjudging benign, recoverable environmental responses as structural deterioration.

[0041] In some technical solutions, when the strain change of each distributed measuring point on the dam abutment slope over time shows a peak at a single location on the distributed strain sensing optical cable with an amplitude exceeding the safety threshold, it is determined that a crack has appeared at that single location. The location of the crack is located based on the position of the single location on the distributed strain sensing optical cable for subsequent repair.

[0042] When the cumulative strain at a certain location on a dam abutment slope exceeds the failure threshold that the material can withstand, physical damage occurs, i.e., the formation or propagation of cracks. When a crack occurs or an existing crack propagates at a certain location on the dam abutment slope, the structural deformation is transmitted to the embedded sensing optical cable, causing the optical cable to generate a local strain concentration at that point that is much larger than the surrounding area, which is manifested as an excessively large peak on the strain increment curve. By determining which measuring point the abnormal peak belongs to, and combining this with the spatial resolution of the optical cable, the meter coordinates of the abnormal peak on the optical cable can be determined. By combining this with the deployment path map of the sensing optical cable, the location of the crack can be accurately located. In some embodiments, the safety threshold includes, but is not limited to, 100µε (micro-strain).

[0043] Because the local strain change sensed by the distributed sensing optical cable measurement points is physically positively correlated with the actual displacement of the crack at that location, a larger amplitude of the abnormal peak indicates a wider crack opening at that location. By analyzing the change of the peak value over time, the development state of the crack can be further understood, determining whether the crack is in a stable, slowly opening, or rapidly expanding stage.

[0044] Example 2 A method for monitoring the structural health of dam abutment slopes based on a distributed strain optical cable according to the system includes: The strain and temperature data of each distributed measuring point on the dam abutment slope are monitored in real time by using distributed strain sensing optical cables and distributed temperature sensing optical cables arranged according to a preset path on the dam abutment slope. In the initial stable state of the dam abutment slope, the zero-point strain data of each distributed measuring point on the dam abutment slope is obtained by subtracting the initial stable strain data from the initial stable temperature data of the corresponding distributed measuring points on the dam abutment slope. Furthermore, in each moment after the initial stable state of the dam abutment slope, the real-time strain data of each distributed measuring point on the dam abutment slope is obtained by subtracting the strain data of each distributed measuring point on the dam abutment slope from the corresponding temperature data of the corresponding distributed measuring points on the dam abutment slope. Based on the real-time strain data of each distributed measuring point on the dam abutment slope and the zero-point strain data of the corresponding distributed measuring points on the dam abutment slope, strain calculation is performed to obtain the strain change of each distributed measuring point on the dam abutment slope over time. The structural health status of the dam abutment slope is assessed based on the development trend of strain changes over time at various distributed measuring points on the slope and the preset periodic environmental disturbance curves.

[0045] Example 3 The present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the method described in Embodiment 2.

[0046] This invention can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented in whole or in part as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0047] It will be readily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of the present invention are included within the protection scope of the present invention.

[0048] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A dam abutment slope structure health monitoring system based on distributed strain optical cable, characterized in that, It includes: The data monitoring module is used to monitor the strain and temperature data of each distributed measuring point on the dam abutment slope in real time using distributed strain sensing optical cables and distributed temperature sensing optical cables arranged according to a preset path on the dam abutment slope. The data correction module is used to obtain the zero-point strain data of each distributed measuring point on the dam abutment slope by subtracting the initial stable strain data of each distributed measuring point on the dam abutment slope from the initial stable temperature data of the corresponding distributed measuring points on the dam abutment slope under the initial stable state; it is also used to obtain the real-time strain data of each distributed measuring point on the dam abutment slope by subtracting the strain data of each distributed measuring point on the dam abutment slope from the corresponding temperature data of the corresponding distributed measuring points on the dam abutment slope at each time after the initial stable state; and to calculate the strain change of each distributed measuring point on the dam abutment slope over time by performing strain calculation based on the real-time strain data of each distributed measuring point on the dam abutment slope and the zero-point strain data of the corresponding distributed measuring points on the dam abutment slope. The data analysis module is used to assess the structural health status of the dam abutment slope based on the development trend of strain changes over time at various distributed measuring points on the dam abutment slope and the preset periodic environmental disturbance curves.

2. The dam abutment slope structure health monitoring system based on distributed strain optical cable according to claim 1, characterized in that: The distributed strain sensing optical cable and the distributed temperature sensing optical cable are laid along an S-shaped path from low to high on the dam shoulder slope, and the turning points of the distributed strain sensing optical cable and the distributed temperature sensing optical cable along the S-shaped path are fixed at the edge of the dam shoulder slope.

3. The dam abutment slope structure health monitoring system based on distributed strain optical cable according to claim 2, characterized in that: The process of deploying distributed strain sensing optical cables and distributed temperature sensing optical cables according to a preset path is as follows: During the layered pouring of concrete on the dam shoulder slope, the distributed strain sensing optical cables and distributed temperature sensing optical cables are fixed in advance along an S-shaped path on the surface of the rock mass on the hillside where the dam shoulder slope is located. The part of the dam shoulder slope above the ground level is divided into multiple sections from low to high, and concrete is poured in sections from low to high. During the concrete pouring process, the flowing concrete automatically covers the distributed strain sensing optical cables and distributed temperature sensing optical cables. After the concrete solidifies, the distributed strain sensing optical cables and distributed temperature sensing optical cables are fixed.

4. The dam abutment slope structure health monitoring system based on distributed strain optical cable according to claim 1, characterized in that: The initial stability strain data and the initial stability temperature data of the corresponding distributed measuring points on the dam abutment slope were obtained after the dam abutment slope was poured and the structure was stabilized.

5. The dam abutment slope structure health monitoring system based on distributed strain optical cable according to claim 4, characterized in that: The method for calculating the strain change of each distributed measuring point on the dam abutment slope over time by using real-time strain data from each distributed measuring point and zero-point strain data from the corresponding distributed measuring points on the dam abutment slope includes: subtracting the real-time strain data values ​​from the corresponding zero-point strain data values ​​of each distributed measuring point on the dam abutment slope point by point to obtain the strain change of each distributed measuring point on the dam abutment slope over time. ,in, For the m-th distributed measuring point on the dam abutment slope The change in strain at any given time. For the m-th distributed measuring point on the dam abutment slope Real-time strain data values ​​at any given moment. This represents the zero-point strain data value corresponding to the m-th distributed measuring point on the dam abutment slope. Let m be the spatial coordinates of the distributed measuring point. This refers to the nth monitoring time.

6. The dam abutment slope structure health monitoring system based on distributed strain optical cable according to claim 5, characterized in that: The method for assessing the structural health status of a dam abutment slope based on the development trend of strain changes over time at various distributed measuring points and a preset periodic environmental disturbance curve includes: within a preset series of sliding time windows, if the variance of strain changes over time at various distributed measuring points on the dam abutment slope is less than a first preset threshold, the dam abutment slope structure is assessed to be in a stable state; or if the cross-correlation coefficient between strain changes over time at various distributed measuring points on the abutment slope and the preset periodic environmental disturbance curve is greater than a second preset threshold, it is determined that strain changes over time at various distributed measuring points on the abutment slope fluctuate periodically with environmental factors, and the dam abutment slope structure is assessed to be in a stable state.

7. The dam abutment slope structure health monitoring system based on distributed strain optical cable according to claim 6, characterized in that: When the strain change of each distributed measuring point on the dam abutment slope over time shows a monotonically increasing or monotonically decreasing trend over multiple consecutive monitoring periods, the residual signal between the strain change of each distributed measuring point on the dam abutment slope over time and the environmental interference component at the corresponding time point in the preset periodic environmental interference curve is calculated. When the residual signal is less than the third preset threshold over multiple consecutive detection periods, it is assessed that the dam abutment slope structure is in a stable state.

8. The dam abutment slope structure health monitoring system based on distributed strain optical cable according to claim 7, characterized in that: When the strain change of each distributed measuring point on the dam abutment slope over time shows a peak amplitude exceeding the safety threshold at a single location on the distributed strain sensing optical cable, it is determined that a crack has appeared at that single location. The location of the crack is located based on the position of the single location on the distributed strain sensing optical cable for subsequent repair.

9. A method for monitoring the structural health of dam abutment slopes based on distributed strain optical cables according to claim 1, characterized in that, include: The strain and temperature data of each distributed measuring point on the dam abutment slope are monitored in real time by using distributed strain sensing optical cables and distributed temperature sensing optical cables arranged according to a preset path on the dam abutment slope. In the initial stable state of the dam abutment slope, the zero-point strain data of each distributed measuring point on the dam abutment slope is obtained by subtracting the initial stable strain data from the initial stable temperature data of the corresponding distributed measuring points on the dam abutment slope. Furthermore, in each moment after the initial stable state of the dam abutment slope, the real-time strain data of each distributed measuring point on the dam abutment slope is obtained by subtracting the strain data of each distributed measuring point on the dam abutment slope from the corresponding temperature data of the corresponding distributed measuring points on the dam abutment slope. Based on the real-time strain data of each distributed measuring point on the dam abutment slope and the zero-point strain data of the corresponding distributed measuring points on the dam abutment slope, strain calculation is performed to obtain the strain change of each distributed measuring point on the dam abutment slope over time. The structural health status of the dam abutment slope is assessed based on the development trend of strain changes over time at various distributed measuring points on the slope and the preset periodic environmental disturbance curves.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 9.

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