Concrete freeze-thaw damage mechanical property evaluation method and system applied to digital line

Abstract

The application provides a concrete freeze-thaw damage mechanical property evaluation method and system applied to a digital line, and relates to the technical field of power grid infrastructure health monitoring and durability evaluation. The method comprises the following steps: acquiring environmental parameters and design parameters of a power transmission line tower site area; calculating a concrete freeze-thaw damage strength parameter based on the minimum temperature and the water-cement ratio; calculating a damage compressive strength according to the concrete freeze-thaw damage strength parameter, the freeze-thaw cycle number and the test compressive strength; calculating a damage compressive elastic modulus and a damage peak stress compressive strain based on the ratio of the damage compressive strength to the test compressive strength; comparing the damage index with a preset threshold value to determine whether the mechanical property meets the safety requirement and outputting a reinforcement prompt. The application realizes accurate quantitative evaluation of the deep mechanical property of concrete under a freeze-thaw environment, and completes digital operation and maintenance transformation from post-repair to pre-control.

Description

Technical Field

[0001] This invention relates to the field of power grid infrastructure health monitoring and durability assessment technology, and more specifically, to a method and system for assessing the mechanical properties of concrete subjected to freeze-thaw damage in digital power lines. Background Technology

[0002] As a crucial component of the power system, the safe and stable operation of transmission lines directly impacts the reliability of the power supply for the entire society. With the continuous expansion of power grid construction and the extension of site selection areas, an increasing number of transmission lines are being deployed in extremely harsh, cold, and high-altitude regions. These unique geographical areas exhibit extremely harsh natural environments, characterized by significant seasonal temperature variations and drastic diurnal temperature fluctuations. The foundations of transmission lines are typically constructed using concrete. Under these special climatic conditions, the foundation concrete structure is exposed to prolonged and frequent alternations of wet and dry conditions and intense freeze-thaw cycles. The damage mechanism of freeze-thaw cycles on concrete materials is complex and destructive: when the ambient temperature drops below freezing, free water in the tiny pores within the concrete freezes and expands, generating enormous frost heave stress on the pore walls; when the temperature rises and the ice and snow melt, moisture further penetrates into newly formed microcracks. This cyclical process of freezing and thawing leads to irreversible damage to the internal microstructure of concrete, which manifests macroscopically as increased porosity and decreased density, resulting in a significant decline in key mechanical indicators related to the load-bearing capacity of concrete.

[0003] In traditional construction and operation and maintenance processes, monitoring methods for the performance degradation of transmission line foundation concrete are often limited to post-construction manual inspections and qualitative experience-based judgments. Maintenance personnel typically rely solely on visual observation, focusing on obvious surface defects such as cracking, spalling, exposed reinforcement, and pitting. However, this subjective experience-based approach suffers from significant limitations and lag. Firstly, a seemingly intact surface does not guarantee the preservation of internal structural mechanical properties; by the time obvious surface defects appear, severe structural damage has often already occurred within the concrete. Secondly, existing methods lack quantitative assessment tools for evaluating the changes in deep mechanical properties of concrete under complex freeze-thaw conditions. Accurate quantitative models have been lacking for understanding the attenuation patterns of core mechanical parameters such as compressive strength, compressive modulus of elasticity, and compressive strain corresponding to peak stress after freeze-thaw damage as a function of environmental changes.

[0004] The lack of such quantitative assessment methods prevents power grid management departments from accurately and proactively controlling the true load-bearing capacity and safety and health status of transmission line foundations during long-term operation and maintenance. Under extreme weather or high-load conditions, concrete foundations that have been subjected to freeze-thaw damage over a long period are highly susceptible to structural instability. This can lead to uneven settlement or tilting of transmission towers, or even major power grid safety accidents such as tower collapse and line breakage, posing a significant threat to the stable operation of the entire power system.

[0005] Furthermore, with the construction of smart grids and the popularization of the digital line concept, the operation and maintenance of transmission lines is transforming towards digitalization and lean management. However, currently, there is no technology that can fully integrate on-site meteorological environmental data and initial concrete design parameters to construct scientific material degradation mechanics criteria, thereby achieving digital, automated, and quantitative assessment of the mechanical properties and safety status of concrete in high-altitude and cold regions. Therefore, the power industry urgently needs a new method to achieve a shift from post-construction surface repair to pre-construction performance control of power grid infrastructure equipment, enabling refined management and control. Summary of the Invention

[0006] The present invention aims to solve at least one of the aforementioned technical problems existing in the prior art.

[0007] Therefore, the first aspect of the present invention provides a method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits.

[0008] A second aspect of the present invention provides a system for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits.

[0009] This invention provides a method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits, comprising: S1. Obtain environmental data and design data of the area where the transmission line tower is located. The environmental data includes the lowest temperature measured on site and the number of freeze-thaw cycles measured on site. The design data includes the water-cement ratio, the test compressive strength and test compressive modulus of concrete under standard curing conditions, and the design values ​​of the concrete compressive strength and compressive modulus of concrete. S2. Based on the measured minimum temperature on site and the water-cement ratio, the freeze-thaw damage strength parameters of concrete are calculated using the preset damage strength parameter calculation criteria. S3. Based on the concrete freeze-thaw damage strength parameters, the number of freeze-thaw cycles measured on site, and the test compressive strength, calculate the compressive strength of the concrete after freeze-thaw damage. S4. Based on the ratio of the damaged compressive strength to the tested compressive strength, the damaged compressive modulus is calculated in conjunction with the tested compressive modulus, and the peak stress compressive strain is calculated. S5. Compare the damage compressive strength, the damage compressive elastic modulus, and the damage peak stress compressive strain with preset judgment thresholds. If all of them meet the corresponding threshold conditions, it is determined that the mechanical properties of the concrete after freeze-thaw damage meet the design and safety requirements. Otherwise, it is determined that the requirements are not met and a reinforcement and repair prompt is output.

[0010] The method for evaluating the mechanical properties of concrete freeze-thaw damage in digital circuits according to the above-described technical solution of the present invention may further have the following additional technical features: In the above technical solution, the method for calculating the concrete freeze-thaw damage strength parameter includes:

[0011] in, Here are the parameters for the freeze-thaw damage strength of concrete; w / c is the water-cement ratio. This refers to the total mass of mixing water in each cubic meter of concrete. The amount of cement used per cubic meter of concrete; This is the lowest temperature measured on-site.

[0012] In the above technical solution, the method for calculating the compressive strength of concrete after freeze-thaw damage includes:

[0013] in, The compressive strength of concrete after freeze-thaw damage; F is the number of freeze-thaw cycles measured on site; This refers to the test compressive strength of concrete under standard curing conditions.

[0014] In the above technical solution, the method for calculating the damage compressive elastic modulus includes:

[0015] in, To compensate for damage to the compressive elastic modulus; It is the compressive modulus of elasticity of concrete under standard curing conditions.

[0016] In the above technical solution, the method for calculating the peak stress-compressive strain of the damage includes:

[0017] in, The peak stress-compressive strain represents the damage peak.

[0018] In the above technical solution, the criteria for determining whether the mechanical properties of concrete after freeze-thaw damage meet the design and safety requirements include:

[0019]

[0020]

[0021] In the formula, This refers to the compressive strength of concrete after freeze-thaw damage. To compensate for damage to the compressive elastic modulus; The peak stress-compressive strain is the damage stress. The test compressive strength of concrete under standard curing conditions; The compressive modulus of elasticity of concrete under standard curing conditions; This is the design value for the compressive strength of concrete; This is the design value for the compressive elastic modulus of concrete.

[0022] In the above technical solution, the methods for obtaining environmental and design data include: importing data on the on-site temperature, water-cement ratio, concrete strength grade, and elastic modulus of the area where the transmission line tower is located into the environmental information database and the design information database in spreadsheet format.

[0023] This invention provides a system for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits, used to perform the method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits as described in any of the above technical solutions. The system includes: The information database is used to receive and store environmental data and design data of the area where the transmission line tower is located. The environmental data includes the lowest temperature measured on site and the number of freeze-thaw cycles measured on site. The design data includes the water-cement ratio, the test compressive strength and compressive modulus of concrete under standard curing conditions, and the design values ​​of the compressive strength and compressive modulus of concrete. The concrete freeze-thaw damage mechanical property assessment center, connected to the database, is used to calculate concrete freeze-thaw damage strength parameters based on the lowest temperature measured on-site and the water-cement ratio; calculate the damaged compressive strength based on the concrete freeze-thaw damage strength parameters, the number of freeze-thaw cycles measured on-site, and the test compressive strength; calculate the damaged compressive elastic modulus and the peak stress-strain based on the damaged compressive strength; and compare the damaged compressive strength, damaged compressive elastic modulus, and peak stress-strain with preset judgment thresholds to output an assessment conclusion. The terminal is connected to the concrete freeze-thaw damage mechanical property assessment center and is used to receive and output the assessment conclusions.

[0024] The above technical solution also includes a graphical user interface window, which is communicatively connected between the concrete freeze-thaw damage mechanical property assessment center and the terminal. The graphical user interface window is used to receive the result data stream containing the evaluation conclusions output by the concrete freeze-thaw damage mechanical property evaluation center. When the evaluation conclusion meets the requirements, the display interface of the graphical user interface window is green; when the evaluation conclusion does not meet the requirements, the display interface of the graphical user interface window is red and outputs a warning signal to trigger a re-inspection command for the corresponding tower location area.

[0025] In the above technical solution, the terminal is used to generate a concrete freeze-thaw damage mechanical property evaluation report in a preset document format from the received result data stream.

[0026] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are: This invention abandons the traditional approach of relying on subjective experience and surface observation (such as cracking and spalling), and innovatively constructs a quantitative evaluation model based on the lowest temperature measured on-site, the number of freeze-thaw cycles, and the water-cement ratio. By accurately calculating key mechanical indicators such as compressive strength, compressive modulus of elasticity, and peak stress-strain after freeze-thaw damage, this invention can intuitively and accurately quantify the degree of damage to the internal microstructure of concrete and the true attenuation of its load-bearing capacity and deformation performance, solving the bottleneck problem that traditional methods cannot accurately control changes in deep mechanical properties.

[0027] This invention enables objective grading and evaluation of the health status and safety margin of transmission line concrete foundations by cross-comparing calculated damaged mechanical performance indicators with preset judgment thresholds from multiple dimensions. Based on scientific damage assessment conclusions and early warning prompts output by the system, maintenance personnel can identify potential structural risk areas in advance and formulate targeted repair, reinforcement, or strengthening plans. This effectively avoids the passive situation of operating with defects or experiencing serious structural instability before emergency repairs are carried out, achieving pre-emptive performance control and precise maintenance, and effectively ensuring the safe and stable operation of power grid infrastructure in harsh and cold environments.

[0028] The evaluation system of this invention tightly integrates environmental information collection, mechanical performance calculation, safety threshold determination, and result visualization into a closed-loop digital processing system. It automatically reads on-site environmental and design data from the system database, intuitively presents the safety status (e.g., red and green color display) using a graphical user interface, and automatically generates standardized evaluation reports from the terminal. This significantly reduces reliance on manual on-site inspections and the risk of human error, improving the efficiency and standardization of detection and evaluation, and providing reliable technical support for high-quality digital and intelligent operation and maintenance of power grid projects.

[0029] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart of a method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the execution logic of a concrete freeze-thaw damage mechanical property evaluation system for digital circuits according to an embodiment of the present invention. Detailed Implementation

[0031] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0033] The following reference Figure 1 and Figure 2 This invention describes a method and system for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits, provided by some embodiments of the present invention.

[0034] Some embodiments of this application provide a method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits.

[0035] This invention addresses the technical challenge of quantitatively assessing the internal damage of concrete foundations in high-altitude and frigid regions under freeze-thaw conditions. It overcomes the limitations of traditional methods relying on surface defect observation by constructing a mechanical performance degradation model that deeply couples environmental factors with material parameters. By introducing the concept of a digital line, this invention acquires real-world, harsh weather data (such as minimum temperature and freeze-thaw cycle count) and initial concrete mix design parameters (such as water-cement ratio and initial mechanical properties) from the transmission line site. Using these as input parameters, and relying on unique calculation criteria for damage strength, elastic modulus, and stress-strain, it accurately quantifies and derives the degree of deep mechanical property degradation of concrete after long-term freeze-thaw cycles. Finally, through multi-dimensional comparison with design safety thresholds, it achieves objective grading and automated early warning of foundation health status, thereby supporting the digital transformation of power grid infrastructure from post-repair to pre-emptive quantitative control.

[0036] Specifically, such as Figure 1As shown in the figure, this embodiment proposes a method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits, which includes the following steps S1 to S5.

[0037] S1. Obtain environmental data and design data of the area where the transmission line tower is located. The environmental data includes the lowest temperature measured on site and the number of freeze-thaw cycles measured on site. The design data includes the water-cement ratio, the test compressive strength and test compressive modulus of concrete under standard curing conditions, and the design values ​​of the concrete compressive strength and compressive modulus of concrete. S2. Based on the measured minimum temperature on site and the water-cement ratio, the freeze-thaw damage strength parameters of concrete are calculated using the preset damage strength parameter calculation criteria. S3. Calculate the compressive strength of concrete after freeze-thaw damage based on the concrete freeze-thaw damage strength parameters, the number of freeze-thaw cycles measured on site, and the test compressive strength. S4. Based on the ratio of the damaged compressive strength to the tested compressive strength, the damaged compressive modulus is calculated in conjunction with the tested compressive modulus, and the peak stress compressive strain is calculated. S5. Compare the damage compressive strength, the damage compressive elastic modulus, and the damage peak stress compressive strain with preset judgment thresholds. If all of them meet the corresponding threshold conditions, it is determined that the mechanical properties of the concrete after freeze-thaw damage meet the design and safety requirements. Otherwise, it is determined that the requirements are not met and a reinforcement and repair prompt is output.

[0038] The detailed implementation process for each step will be described below.

[0039] In step S1, environmental data and design data of the area where the transmission line tower is located are obtained. The environmental data includes the lowest temperature measured on site and the number of freeze-thaw cycles measured on site. The design data includes the water-cement ratio, the test compressive strength and test compressive modulus of concrete under standard curing conditions, and the design values ​​of the concrete compressive strength and compressive modulus of elasticity.

[0040] As the initial data input for digital line assessment, step S1 aims to comprehensively collect core parameters that reflect the characteristics of harsh external environments and the material properties of the foundation concrete itself. High-altitude and cold regions have harsh climatic conditions; therefore, the lowest measured temperature and the number of measured freeze-thaw cycles in the environmental data are key external indicators characterizing the intensity of freeze-thaw damage in these areas. Meanwhile, the water-cement ratio in the design data directly determines the porosity and density of the concrete, which are the primary intrinsic material factors affecting its freeze-thaw resistance. The experimental compressive strength and experimental compressive modulus of elasticity represent the initial mechanical benchmarks of this batch of concrete under ideal, undamaged conditions, used for subsequent calculations of relative attenuation. The corresponding design values ​​for compressive strength and compressive modulus of elasticity serve as the fundamental red lines that cannot be crossed in the final safety assessment. By comprehensively acquiring these two types of data, complete data support is provided for the subsequent construction of a deeply coupled quantitative assessment model.

[0041] In some embodiments, to ensure the efficiency and standardization of data processing, the acquisition of environmental and design data includes: importing data on the on-site temperature, water-cement ratio, concrete strength grade, test compressive strength, and test compressive modulus of elasticity of the area where the transmission line tower is located into the corresponding environmental information nodes and design information nodes (represented as data sets of environmental information databases and design information databases in subsequent system embodiments) in a preset data format. This standardized data import method enables the evaluation method to quickly read and process massive amounts of tower node parameters, adapting to the data scale of long-distance transmission lines in vast areas.

[0042] In one specific embodiment, the preset data format can be a spreadsheet file format. Since geological survey data, meteorological monitoring data, and civil construction records in the early stages of power grid construction are usually stored in tabular form, organizing the basic parameters collected on-site into .xls or .xlsx format files and directly importing them into the evaluation process not only greatly reduces the cost of data conversion but also facilitates operation and communication for frontline construction and maintenance personnel, thereby improving the convenience and feasibility of this evaluation method in practical engineering applications.

[0043] In step S2, based on the lowest temperature measured on site and the water-cement ratio, the freeze-thaw damage strength parameters of concrete are calculated using a preset damage strength parameter calculation criterion.

[0044] Step S2 is a core prerequisite for the quantitative assessment model. The severity of freeze-thaw damage to concrete under harsh environments is not determined by a single factor, but rather by the deep coupling effect of external extreme weather conditions and the internal material resistance. The lowest temperature measured on-site determines the magnitude of frost heave stress generated when pore water inside the concrete freezes. The lower the temperature, the higher the freezing rate of water in the pores, and the stronger the resulting volume expansion and frost heave destructive force. The water-cement ratio directly determines the internal microstructure and free water content of the concrete after molding. Concrete with a higher water-cement ratio has more capillary pores, making it easier for external moisture to penetrate and resulting in a more significant effect of freezing expansion and destructive force, leading to poorer freeze-thaw resistance. Therefore, this invention abandons the traditional assessment method that separates the environment and the material, and couples these two key indicators for calculation to derive damage strength parameters characterizing the constitutive degradation rate of the material.

[0045] In one specific embodiment, the preset damage strength parameter calculation criterion is used to calculate the concrete freeze-thaw damage strength parameter according to the following formula:

[0046] in, Here are the parameters for the freeze-thaw damage strength of concrete; w / c is the water-cement ratio. This refers to the total mass of mixing water in each cubic meter of concrete. The amount of cement used per cubic meter of concrete; This is the lowest temperature measured on-site.

[0047] In the formula model of the above specific embodiment, the natural logarithm function is introduced to characterize the nonlinear aggravation of the damage effect of the minimum temperature. That is, as the temperature decreases below the freezing point, its aggravating effect on freeze-thaw damage conforms to this logarithmic law. At the same time, the water-cement ratio, as a core weighting coefficient, is deeply involved in the adjustment of the coefficient of the temperature logarithmic term and the baseline constant term. This calculation criterion fully fits the degradation law of actual engineering in high-altitude and cold regions, considering not only the absolute value of temperature but also the amplification effect of material porosity on temperature sensitivity. In this way, the structural damage evolution rate of foundation concrete under specific extreme climates can be quantified more accurately and scientifically, laying a very solid numerical foundation for the subsequent calculation of deep compressive strength and deformation mechanical properties.

[0048] In step S3, the compressive strength of concrete after freeze-thaw damage is calculated based on the concrete freeze-thaw damage strength parameters, the number of freeze-thaw cycles measured on site, and the test compressive strength.

[0049] Step S3 is a further extrapolation and calculation based on the aforementioned damage strength parameters, aiming to quantify the cumulative degradation effect of concrete compressive bearing capacity over time (number of freeze-thaw cycles). In actual high-altitude and cold natural environments, the decline in the mechanical properties of concrete is a structural damage evolution process that gradually accumulates with seasonal changes and repeated freeze-thaw cycles. The concrete freeze-thaw damage strength parameters obtained in step S2 essentially characterize the relative mechanical deceleration rate of the material under a single freeze-thaw cycle or unit environmental action. Coupled with this deceleration rate and the number of freeze-thaw cycles measured on-site, the total cumulative damage suffered by the power transmission foundation concrete within a specific service life can be accurately depicted. Finally, this cumulative damage measure is applied to the test compressive strength under standard curing conditions (i.e., the ideal initial state benchmark without damage), thereby scientifically calculating the true residual compressive capacity of the concrete under the current state. This calculation logic breaks away from the crude mode of qualitatively estimating strength based solely on surface spalling and cracking in traditional inspections, realizing the quantitative determination of compressive strength, a core safety indicator of engineering.

[0050] In one specific embodiment, the compressive strength of the concrete after freeze-thaw damage is calculated according to the following formula:

[0051] in, The compressive strength of concrete after freeze-thaw damage; F is the number of freeze-thaw cycles measured on site; This refers to the test compressive strength of concrete under standard curing conditions.

[0052] In the calculation criteria of the above formula, The term represents the total cumulative damage reduction factor of concrete material after undergoing F freeze-thaw cycles in actual field conditions. By subtracting this cumulative reduction factor, the dimensionless residual strength ratio is calculated. Finally, multiplying by the test compressive strength benchmark value under the above-mentioned undamaged condition completes the rigorous conversion from theoretical damage ratio to actual mechanical parameter dimensions. This linear reduction model not only ensures the efficiency of the underlying calculation of the digital evaluation system, but also accurately captures the core physical essence of the monotonically increasing macroscopic damage effect of materials with the number of cyclic erosion cycles.

[0053] In step S4, based on the ratio of the damaged compressive strength to the test compressive strength, the damaged compressive modulus and the peak stress-strain of the damage are calculated in conjunction with the test compressive modulus.

[0054] Step S4 overcomes the limitations of relying solely on a single strength index for safety evaluation, constructing a deep correlation model between concrete strength decay and deformation capacity degradation. In the actual stress scenarios of transmission line foundation engineering, the overall stability of the foundation structure depends not only on its ultimate bearing capacity against crushing (i.e., compressive strength), but also highly on its stiffness against deformation under stress (characterized by compressive elastic modulus), and the deformation characteristics of the material when it reaches its ultimate failure state (characterized by peak stress-compressive strain). The propagation of internal microcracks caused by freeze-thaw cycles leads to a complex synergistic degradation law of the material's strength and stiffness. This invention creatively uses the "ratio of damaged compressive strength to experimental compressive strength" (i.e., the proportion of relative residual strength) as the core parameter for quantifying the degree of damage to the internal microstructure of the material. Based on this, combined with the initial elastic modulus benchmark under undamaged conditions, the deformation and ductility indices after damage are derived, thereby comprehensively and three-dimensionally reconstructing the constitutive mechanical characteristics of concrete foundations after freeze-thaw erosion.

[0055] In one specific embodiment, the damage compressive modulus of elasticity is calculated according to the following formula:

[0056] in, To compensate for damage to the compressive elastic modulus; It is the compressive modulus of elasticity of concrete under standard curing conditions.

[0057] In the above-mentioned calculation criteria for the elastic modulus, the system models the degradation law of the stiffness parameter as an exponential function relationship based on the ratio of relative residual strength. This nonlinear mathematical model accurately reflects that, in the early stage of freeze-thaw damage, the weakening effect of microcracks on stiffness is often more sensitive than the weakening effect on strength.

[0058] In another specific embodiment, the peak stress-compressive strain of the damage is calculated according to the following formula:

[0059] in, The peak stress-compressive strain represents the damage peak.

[0060] In this calculation criterion, the model linearly adjusts the residual strength ratio and further introduces the strength modulus ratio of the base material itself for dimensional transformation and failure characteristic mapping. Accurate determination of peak stress-compressive strain is of crucial engineering significance for precisely assessing whether transmission foundations damaged by freeze-thaw cycles will experience brittle fracture or ductile failure when subjected to unbalanced pull-out loads caused by extreme icing and strong winds. This effectively fills the gap in traditional operation and maintenance inspections regarding the lack of a system for predicting deformation failure modes.

[0061] In step S5, the damage compressive strength, the damage compressive elastic modulus, and the damage peak stress compressive strain are compared with preset judgment thresholds. If all of them meet the corresponding threshold conditions, it is determined that the mechanical properties of the concrete after freeze-thaw damage meet the design and safety requirements; otherwise, it is determined that the requirements are not met and a reinforcement and repair prompt is output.

[0062] Step S5 is the data decision-making and risk output endpoint of the entire assessment method. Through the coupled calculations of the preceding steps, the system has acquired three core mechanical indicators that quantitatively characterize the current internal structural state of the concrete foundation. Due to the harsh operating conditions of transmission line tower foundations (such as strong winds and the enormous overturning moment caused by heavy icing), their safety requires not only sufficient compressive bearing capacity to prevent crushing and sufficient stiffness to limit tower foot displacement and uneven settlement, but also reasonable strain characteristics to prevent sudden brittle failure. Therefore, this step establishes a multi-dimensional joint judgment mechanism. Only when the strength, elastic modulus, and deformation indicators are all within the safety envelope is a "satisfactory" safety conclusion given. This "one-vote veto" multi-dimensional assessment logic greatly improves the reliability of power grid facility health assessment under freeze-thaw conditions, fundamentally eliminating the phenomenon of "operating with defects" where a single indicator appears qualified but the overall structure already has serious hidden dangers.

[0063] In one specific embodiment, the criteria for determining whether the mechanical properties of concrete after freeze-thaw damage meet design and safety requirements include:

[0064]

[0065]

[0066] In the formula, This refers to the compressive strength of concrete after freeze-thaw damage. To compensate for damage to the compressive elastic modulus; The peak stress-compressive strain is the damage stress. The test compressive strength of concrete under standard curing conditions; The compressive modulus of elasticity of concrete under standard curing conditions; This is the design value for the compressive strength of concrete; This is the design value for the compressive elastic modulus of concrete.

[0067] In the aforementioned preset threshold system, both the damaged compressive strength and the damaged compressive modulus of elasticity are reduced by 0.7 times the initial test benchmark value. This means that once the absolute strength or stiffness loss of the base material reaches or exceeds 25% due to long-term freeze-thaw cumulative damage, even if there are no visible large-area cracks or spalling on the concrete surface, the structure has lost the necessary safety margin in a deep mechanical sense. Simultaneously, the system introduces the theoretical ratio of the initial design value of the concrete's compressive strength to the design value of its compressive modulus of elasticity as a rigid upper limit constraint on compressive strain to ensure that the deformation characteristics of the material damaged by freeze-thaw near its ultimate bearing capacity are strictly controlled within the theoretical deformation tolerance range of the original engineering design.

[0068] If any of the three indicators mentioned above fails the corresponding threshold test, the evaluation process will automatically determine that the mechanical performance of the current tower foundation structure does not meet safety requirements. In actual digital line operation and maintenance scenarios, the system will output a clear reinforcement and repair prompt at this time. Combined with the communication link of the digital platform, this prompt can be manifested as a red warning window popping up on the system interface of the evaluator, followed by the conversion of the relevant data stream into a standard format (such as .pdf or .doc) "Mechanical Performance Evaluation Report of Concrete Freeze-Thaw Damage in High-Altitude and Cold Regions".

[0069] Combination Figure 2 As shown, other embodiments of the present invention also provide a system for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits, the system being used to perform the method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits as described in any of the foregoing embodiments.

[0070] The system includes a database. In some embodiments, the database can be logically divided into an environmental database and a design database. The database receives and stores environmental and design data for the area where the transmission line towers are located. The environmental data includes the lowest measured temperature and the number of measured freeze-thaw cycles. The design data includes the water-cement ratio, the test compressive strength and test compressive modulus of elasticity of concrete under standard curing conditions, and the design values ​​of the concrete compressive strength and compressive modulus of elasticity. By constructing a dedicated database, the digital power grid platform can easily classify, aggregate, and persistently manage multi-source infrastructure data.

[0071] The system also includes a concrete freeze-thaw damage mechanical property assessment center connected to the database. This center serves as the data processing and calculation hub of the system, internally configured with and calling upon a freeze-thaw damage mechanical property calculation criterion library. This library covers calculation criteria for freeze-thaw damage compressive strength, freeze-thaw damage compressive elastic modulus, and freeze-thaw damage peak stress-compressive strain. The assessment center reads parameters from the database, calculates concrete freeze-thaw damage strength parameters based on the lowest measured temperature and the water-cement ratio; calculates damaged compressive strength based on the concrete freeze-thaw damage strength parameters, the number of measured freeze-thaw cycles, and the experimental compressive strength; calculates damaged compressive elastic modulus and peak stress-compressive strain based on the damaged compressive strength; and cross-compares the damaged compressive strength, damaged compressive elastic modulus, and peak stress-compressive strain with preset judgment thresholds to deduce and output an assessment conclusion.

[0072] The system also includes a terminal connected to the evaluation center, used to receive and ultimately output the evaluation conclusion.

[0073] In some embodiments, the system further includes a graphical user interface (GUI) window, which is communicatively connected between the assessment center and the terminal. The GUI window receives a result data stream containing assessment conclusions output by the assessment center. In one specific embodiment, to achieve intuitive and automated early warning for operation and maintenance monitoring, the GUI window displays green when the assessment conclusion meets the requirements; and displays red when the assessment conclusion does not meet the requirements, simultaneously outputting an early warning signal to trigger a re-inspection command for the corresponding transmission line tower location area. This striking visual interactive feedback mechanism assists the on-duty personnel of the power grid monitoring center in quickly locating tower locations with potential freeze-thaw risks among a massive number of nodes.

[0074] In one specific embodiment, the terminal is used to automatically generate a report on the mechanical properties of concrete in high-altitude and cold regions due to freeze-thaw damage from the received result data stream in a preset document format (e.g., .pdf or .doc electronic file format). This results in a finished document within the digital line management system, facilitating online internal review and approval by power grid owners, maintenance and construction units.

[0075] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits, characterized in that, include: S1. Obtain environmental data and design data of the area where the transmission line tower is located. The environmental data includes the lowest temperature measured on site and the number of freeze-thaw cycles measured on site. The design data includes the water-cement ratio, the test compressive strength and test compressive modulus of concrete under standard curing conditions, and the design values ​​of the concrete compressive strength and compressive modulus of concrete. S2. Based on the measured minimum temperature on site and the water-cement ratio, the freeze-thaw damage strength parameters of concrete are calculated using the preset damage strength parameter calculation criteria. S3. Based on the concrete freeze-thaw damage strength parameters, the number of freeze-thaw cycles measured on site, and the test compressive strength, calculate the compressive strength of the concrete after freeze-thaw damage. S4. Based on the ratio of the damaged compressive strength to the tested compressive strength, the damaged compressive modulus is calculated in conjunction with the tested compressive modulus, and the peak stress compressive strain is calculated. S5. Compare the damage compressive strength, the damage compressive elastic modulus, and the damage peak stress compressive strain with preset judgment thresholds. If all of them meet the corresponding threshold conditions, it is determined that the mechanical properties of the concrete after freeze-thaw damage meet the design and safety requirements. Otherwise, it is determined that the requirements are not met and a reinforcement and repair prompt is output.

2. The method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits according to claim 1, characterized in that, The calculation method for the concrete freeze-thaw damage strength parameter includes: in, Here are the parameters for the freeze-thaw damage strength of concrete; w / c is the water-cement ratio. The total mass of mixing water in each cubic meter of concrete. The amount of cement used per cubic meter of concrete; This is the lowest temperature measured on-site.

3. The method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits according to claim 2, characterized in that, The method for calculating the compressive strength of concrete after freeze-thaw damage includes: in, The compressive strength of concrete after freeze-thaw damage; F is the number of freeze-thaw cycles measured on site; This refers to the test compressive strength of concrete under standard curing conditions.

4. The method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits according to claim 3, characterized in that, The method for calculating the damage compressive elastic modulus includes: in, To compensate for damage to the compressive elastic modulus; It is the compressive modulus of elasticity of concrete under standard curing conditions.

5. The method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits according to claim 4, characterized in that, The method for calculating the peak stress-compressive strain of the damage includes: in, The peak stress-compressive strain represents the damage peak.

6. The method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits according to claim 1, characterized in that, The criteria for determining whether the mechanical properties of concrete after freeze-thaw damage meet design and safety requirements include: In the formula, This refers to the compressive strength of concrete after freeze-thaw damage. To compensate for damage to the compressive elastic modulus; The peak stress-compressive strain is the damage stress. The test compressive strength of concrete under standard curing conditions; The compressive modulus of elasticity of concrete under standard curing conditions; This is the design value for the compressive strength of concrete; This is the design value for the compressive elastic modulus of concrete.

7. The method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits according to claim 1, characterized in that, The methods for obtaining environmental and design data include: importing data on the on-site temperature, water-cement ratio, concrete strength grade, and elastic modulus of the area where the transmission line tower is located into the environmental information database and the design information database in spreadsheet format.

8. A system for evaluating the mechanical properties of concrete subjected to freeze-thaw damage in digital circuits, characterized in that, The system is used to perform the method for evaluating the mechanical properties of concrete subjected to freeze-thaw damage applied to digital lines as described in any one of claims 1 to 7, the system comprising: The information database is used to receive and store environmental data and design data of the area where the transmission line tower is located. The environmental data includes the lowest temperature measured on site and the number of freeze-thaw cycles measured on site. The design data includes the water-cement ratio, the test compressive strength and compressive modulus of concrete under standard curing conditions, and the design values ​​of the compressive strength and compressive modulus of concrete. The concrete freeze-thaw damage mechanical property assessment center, connected to the database, is used to calculate concrete freeze-thaw damage strength parameters based on the lowest temperature measured on-site and the water-cement ratio; calculate the damaged compressive strength based on the concrete freeze-thaw damage strength parameters, the number of freeze-thaw cycles measured on-site, and the test compressive strength; calculate the damaged compressive elastic modulus and the peak stress-strain based on the damaged compressive strength; and compare the damaged compressive strength, damaged compressive elastic modulus, and peak stress-strain with preset judgment thresholds to output an assessment conclusion. The terminal is connected to the concrete freeze-thaw damage mechanical property assessment center and is used to receive and output the assessment conclusions.

9. The concrete freeze-thaw damage mechanical property evaluation system for digital circuits according to claim 8, characterized in that, It also includes a graphical user interface window, which is communicatively connected between the concrete freeze-thaw damage mechanical property assessment center and the terminal. The graphical user interface window is used to receive the result data stream containing the evaluation conclusions output by the concrete freeze-thaw damage mechanical property evaluation center. When the evaluation conclusion meets the requirements, the display interface of the graphical user interface window is green; when the evaluation conclusion does not meet the requirements, the display interface of the graphical user interface window is red and outputs a warning signal to trigger a re-inspection command for the corresponding tower location area.

10. The concrete freeze-thaw damage mechanical property evaluation system for digital circuits according to claim 9, characterized in that, The terminal is used to generate a concrete freeze-thaw damage mechanical property assessment report from the received result data stream in a preset document format.

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