A method for evaluating a substation concrete foundation

Abstract

The application discloses a kind of substation concrete foundation evaluation methods, it is related to substation technical field, including: the surface environmental parameter of reinforced concrete deck slab is collected, including chloride ion, sulfate ion and carbonate ion etc.;While measuring deck slab protection cap thickness;Reinforced concrete deck slab is located above 3 PHC pipe piles;The best frequency of vibration measuring device is calibrated by test;Under the calibration of best frequency, the dynamic detection and analysis of the bearing capacity of reinforced concrete deck slab is carried out by vibration measuring device, and the bearing deviation index Yz of reinforced concrete deck slab is calculated according to the maximum dynamic elastic modulus Ed and crack detection result;The surface environmental parameter measured, deck slab protection cap thickness and bearing deviation index Yz are input data of life evaluation model, and the life prediction data corresponding to reinforced concrete deck slab is obtained;It improves prediction efficiency and accuracy;To improve regional decision efficiency.

Description

Technical Field

[0001] This invention relates to the field of substation technology, specifically a method for evaluating substation concrete foundations. Background Technology

[0002] Substations are the lifeline of national economic development and construction. Their foundations are the foundation of power transmission and transformation equipment, and their reliability is crucial for the safe operation of the power grid. Unlike concrete in other fields, the concrete foundations of substation equipment are mostly exposed to the natural environment (affected by temperature, humidity, corrosion, etc.) and bear the alternating dynamic and static loads of various transmission and transformation equipment for extended periods. This makes the concrete foundations prone to cracks and voids, which exacerbates steel corrosion, significantly reduces the load-bearing capacity of the substation foundations, and seriously endangers the safe operation of the power grid.

[0003] Currently, the main methods for on-site assessment of concrete strength are curing under the same conditions and ultrasonic rebound and core sampling. Among these, curing under the same conditions results in significant differences due to the influence of specimen size and varying operator skill levels, especially for large-volume concrete with large internal and external temperature differences. Curing under the same conditions can no longer objectively reflect the strength development of the concrete structure, particularly the internal concrete. Based on these shortcomings, this invention proposes an assessment method for substation concrete foundations. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a method for evaluating substation concrete foundations. This invention comprehensively considers the combined effects of complex environmental factors (such as chloride ions, sulfate ions, and carbonate ions), dynamic and static loads, and the thickness of the protective cap to evaluate the concrete foundation and determine its usable lifespan. The evaluation object of this invention is a PHC pipe pile group foundation (connected by a concrete cap on top). The prediction method is based on the combined factors of ① complex environmental factors (such as chloride ions, sulfate ions, and carbonate ions), ② dynamic and static loads, and ③ the thickness of the cap to predict the pile foundation's lifespan.

[0005] To achieve the above objectives, an embodiment of the first aspect of the present invention provides a method for evaluating concrete foundations of substations, comprising the following steps:

[0006] Step 1: Collect surface environmental parameters of the reinforced concrete foundation, including chloride ion, sulfate ion and carbonate ion; at the same time, measure the thickness of the protective cap of the foundation.

[0007] Step 2: A reinforced concrete foundation is located above three PHC pipe piles; the upper part of the PHC pipe piles is connected by the reinforced concrete foundation; a vibration measuring device is placed on the surface of the reinforced concrete foundation; the optimal frequency of the vibration measuring device is calibrated through testing.

[0008] The vibration measuring device includes a hydraulic cylinder, a connecting shaft, tires, an ultrasonic probe, and a drive motor connected to the connecting shaft via an internal gear transmission; the piston of the hydraulic cylinder is connected to the connecting shaft, and tires are provided on both sides of the connecting shaft;

[0009] Step 3: At the calibrated optimal frequency, the bearing capacity of the reinforced concrete foundation is dynamically tested and analyzed using a vibration measurement device. The specific testing and analysis process is as follows:

[0010] S31: At the calibrated optimal frequency, start the drive motor to rotate the connecting shaft; measure the maximum dynamic spring modulus Ed at this frequency.

[0011] S32: Divide the surface of the reinforced concrete foundation into n regions on an equal basis. Set up a plane coordinate system based on the surface of the foundation and mark the coordinates of the n regions as (Xn, Yn). Obtain the pressure values ​​of the n regions during dynamic bearing pressure testing and mark the pressure values ​​of the n regions as Yn.

[0012] S33: Obtain the standard pressure value through the cloud server, then control the output pressure of the hydraulic cylinder to reach the preset standard pressure value, and use an ultrasonic probe to detect cracks on the surface of the bearing platform;

[0013] S34: Based on the maximum dynamic resilient modulus Ed and crack detection results, the compressive performance of the reinforced concrete foundation is dynamically analyzed, and the compressive deviation index Yz of the reinforced concrete foundation is calculated.

[0014] Step 4: Use the measured surface environment parameters, the thickness of the protective cap of the foundation, and the bearing pressure deviation index Yz as input data for the life assessment model to obtain the life prediction data of the corresponding reinforced concrete foundation.

[0015] Furthermore, the specific calculation steps for the pressure deviation index Yz are as follows:

[0016] The surface area of ​​the bearing platform where cracks appear is marked as Bv. The number of areas Bv is counted, and the proportion of areas Bv is obtained as Bz. The proportion of areas Bv is the ratio of the number of areas Bv to n. The pressure value corresponding to the appearance of cracks in area Bv is obtained and marked as Ybv.

[0017] The pressure difference YL1 is calculated by comparing Ybv with the standard pressure value. The pressure difference YL1 is compared with the preset pressure difference threshold. The percentage of times YL1 > the preset pressure difference threshold is Lb1. When YL1 > the preset pressure difference threshold, the difference between YL1 and the preset pressure difference threshold is obtained and summed to obtain the pressure difference CZ.

[0018] The bearing pressure deviation index Yz of the reinforced concrete foundation is calculated using the formula Yz=f×Bz×(Lb1×a1+CZ×a2) / (Ed×a3), where a1, a2, and a3 are preset coefficient factors; and f is a preset equilibrium coefficient.

[0019] Furthermore, the optimal frequency of the vibration measuring device is calibrated through experiments. The specific steps are as follows:

[0020] In the same filler, at the optimum moisture content, the relationship between the internal strength of concrete and the maximum dynamic resilient modulus Ed was measured by vibrating at different frequencies. The optimum frequency was determined by data fitting analysis. At the optimum frequency, the dispersion between strength and maximum dynamic resilient modulus Ed was minimized.

[0021] Furthermore, step S31 also includes:

[0022] The connecting shaft drives the tires on both sides to rotate synchronously. A belt is fitted on the side circumference of the reinforced concrete foundation. When the tires rotate, the friction between the tire surface and the belt surface drives the belt to run, so that while the tires are rotating at high speed, the foundation surface is stationary relative to the tires.

[0023] Furthermore, the specific steps for constructing the life assessment model are as follows:

[0024] Potential life correlation data of reinforced concrete foundations under different scenarios were collected as sample data; potential life correlation data included surface environment parameters, foundation protective cap thickness and bearing pressure deviation index.

[0025] The parameters of the sample data are optimized, including epoch optimization, batch size optimization and number of neurons optimization in sequence.

[0026] The sample data is divided into training set, test set and validation set according to a set ratio. Then the training set, test set and validation set are input into the BERT model to train the life assessment model.

[0027] Furthermore, the semantic extraction layer of the BERT model is a multi-layer bidirectional decoder with a Transformer encoder as the basic unit, which includes three parts: attention mechanism, layer normalization and residual connection, and feedforward neural network.

[0028] Furthermore, it also includes: comparing the pressure deviation index Yz with a preset deviation threshold;

[0029] If Yz is greater than the preset deviation threshold, the reinforced concrete foundation is determined to have weak bearing capacity, and a maintenance and reinforcement signal is generated to remind management personnel to carry out maintenance and reinforcement of the reinforced concrete foundation.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. This invention collects surface environmental parameters of the reinforced concrete foundation, including chloride ions, sulfate ions, and carbonate ions; simultaneously measures the thickness of the foundation's protective cap; the reinforced concrete foundation is located above three PHC pipe piles; a vibration measuring device is placed on the surface of the reinforced concrete foundation; the optimal frequency of the vibration measuring device is calibrated through testing; at the calibrated optimal frequency, the bearing capacity of the reinforced concrete foundation is dynamically detected and analyzed using the vibration measuring device; the bearing deviation index Yz of the reinforced concrete foundation is calculated based on the maximum dynamic resilient modulus Ed and crack detection results; if Yz is greater than a preset deviation threshold, the bearing capacity of the reinforced concrete foundation is determined to be weak, and a maintenance and reinforcement signal is generated; this serves to remind management personnel to carry out maintenance and reinforcement of the reinforced concrete foundation to ensure the safe operation of the power grid;

[0032] 2. This invention collects potential life-related data of reinforced concrete foundations under different scenarios as sample data; the potential life-related data includes surface environment parameters, foundation cap thickness, and bearing pressure deviation index; the sample data is optimized; the sample data is divided into training set, test set, and validation set according to a set ratio, and then the training set, test set, and validation set are input into the BERT model to train the life assessment model; the measured surface environment parameters, foundation cap thickness, and bearing pressure deviation index are used as input data for the life assessment model to obtain the corresponding life prediction data of the reinforced concrete foundation; improving prediction efficiency and accuracy; thereby improving regional decision-making efficiency. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram illustrating the principle of a substation concrete foundation evaluation method according to the present invention.

[0035] Figure 2 This is a top view of the reinforced concrete foundation in this invention.

[0036] Figure 3 This is a schematic diagram of the connection between the PHC pipe pile and the reinforced concrete foundation in this invention.

[0037] Figure 4 This is a schematic diagram of the vibration measuring device in this invention. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] The main factors affecting the internal strength of concrete include: filler (particle size) and moisture content; for the same filler, the internal strength of concrete has a non-linear relationship with moisture content; concrete can only obtain the best internal strength at the optimum moisture content.

[0040] Based on the study of the characteristics of medium and coarse-grained soil-rock mixed foundation, the dynamic resilient modulus Ed of the roadbed is different for foundations with different fill materials under the same vibration source; for the same fill material, under the same vibration source, different strengths also have different dynamic resilient moduli Ed.

[0041] This invention aims to detect the dynamic resilient modulus Ed of the roadbed, determine appropriate strength control parameters through experiments, and thus establish the relationship between the dynamic resilient modulus Ed and the internal strength.

[0042] Meanwhile, this invention comprehensively considers the combined effects of complex environment (such as chloride ions, sulfate ions and carbonate ions), dynamic and static loads, and protective cap thickness to evaluate the lifespan of concrete foundations and determine their usable lifespan.

[0043] This assessment primarily focuses on crack analysis of reinforced concrete foundation caps to conduct a life assessment.

[0044] like Figures 1 to 4 As shown, a method for evaluating concrete foundations of substations includes the following steps:

[0045] Step 1: Collect surface environmental parameters of the reinforced concrete foundation, including chloride ions, sulfate ions, and carbonate ions; at the same time, measure the thickness of the protective cap of the foundation.

[0046] Step Two: A reinforced concrete foundation is located above the three PHC pipe piles; the upper part of the PHC pipe piles is connected by the reinforced concrete foundation; a vibration measuring device is placed on the surface of the reinforced concrete foundation; the optimal frequency of the vibration measuring device is calibrated through testing, and the specific steps are as follows:

[0047] In the same filler, at the optimum moisture content, the relationship between the internal strength of concrete and the maximum dynamic resilient modulus Ed was measured by vibrating at different frequencies. The optimum frequency was determined by data fitting analysis. At the optimum frequency, the dispersion between strength and maximum dynamic resilient modulus Ed was minimized.

[0048] The vibration measurement device includes a hydraulic cylinder, a connecting shaft, tires, an ultrasonic probe, and a drive motor connected to the connecting shaft via an internal gear transmission; the piston of the hydraulic cylinder is connected to the connecting shaft, and tires are installed on both sides of the connecting shaft.

[0049] Step 3: At the calibrated optimal frequency, the bearing capacity of the reinforced concrete foundation is dynamically tested and analyzed using a vibration measurement device. The specific testing and analysis process is as follows:

[0050] S31: At the calibrated optimal frequency, start the drive motor to drive the connecting shaft to rotate; the connecting shaft drives the tires on both sides to rotate synchronously. A belt is fitted on the side circumference of the reinforced concrete foundation. When the tires rotate, the friction between the tire surface and the belt surface drives the belt to run, so that while the tires are rotating at high speed, the foundation surface is stationary relative to the tires; measure the maximum dynamic resilient modulus Ed at this frequency; the larger the maximum dynamic resilient modulus Ed, the greater the internal strength of the concrete.

[0051] S32: Divide the surface of the reinforced concrete foundation into n regions on an equal basis. Set up a plane coordinate system based on the surface of the foundation and mark the coordinates of the n regions as (Xn, Yn). Obtain the pressure values ​​of the n regions during dynamic bearing pressure testing and mark the pressure values ​​of the n regions as Yn.

[0052] S33: Obtain the standard pressure value through the cloud server, then control the output pressure of the hydraulic cylinder to reach the preset standard pressure value, and use an ultrasonic probe to detect cracks on the surface of the bearing platform;

[0053] S34: Dynamic analysis of the bearing capacity of reinforced concrete foundations is conducted based on the maximum dynamic resilient modulus Ed and crack detection results; specifically:

[0054] The surface area of ​​the foundation with cracks is marked as Bv. The number of regions Bv is counted, and the proportion of regions Bv is obtained as Bz. The proportion of regions Bv is the ratio of the number of regions Bv to n.

[0055] Obtain the pressure value corresponding to the appearance of cracks in region Bv and mark it as Ybv; calculate the pressure difference YL1 by comparing Ybv with the standard pressure value.

[0056] Compare the pressure difference value YL1 with the preset pressure difference threshold; count the percentage of times YL1 > preset pressure difference threshold as Lb1. When YL1 > preset pressure difference threshold, obtain the difference between YL1 and preset pressure difference threshold and sum them to obtain the bearing pressure difference value CZ; calculate the bearing pressure deviation index Yz of the reinforced concrete foundation using the formula Yz = f × Bz × (Lb1 × a1 + CZ × a2) / (Ed × a3), where a1, a2, and a3 are preset coefficient factors; f is the preset equilibrium coefficient.

[0057] Step 4: Use the measured surface environment parameters, the thickness of the protective cap of the foundation, and the bearing pressure deviation index as input data for the life assessment model to obtain the life prediction data of the corresponding reinforced concrete foundation.

[0058] The specific steps for constructing the life assessment model are as follows:

[0059] Potential life correlation data of reinforced concrete foundations under different scenarios were collected as sample data; potential life correlation data included surface environment parameters, foundation protective cap thickness and bearing pressure deviation index.

[0060] The parameters of the sample data are optimized, including epoch optimization, batch size optimization and number of neurons optimization in sequence.

[0061] The sample data is divided into training set, test set and validation set according to a set ratio. Then the training set, test set and validation set are input into the BERT model to train the life assessment model.

[0062] The semantic extraction layer of the BERT model is a multi-layer bidirectional decoder with a Transformer encoder as the basic unit. It mainly includes three parts: attention mechanism, layer normalization and residual connection, and feedforward neural network.

[0063] In this embodiment, the method further includes: comparing the bearing capacity deviation index Yz of the reinforced concrete foundation with a preset deviation threshold; if Yz is greater than the preset deviation threshold, it is determined that the bearing capacity of the reinforced concrete foundation is weak, and a maintenance and reinforcement signal is generated; so as to remind the management personnel to carry out maintenance and reinforcement of the reinforced concrete foundation to ensure the safe operation of the power grid.

[0064] The above formulas are all numerical calculations after removing dimensions. The formulas are obtained by software simulation based on a large amount of data and are closest to the real situation. The preset parameters and preset thresholds in the formulas are set by those skilled in the art according to the actual situation or obtained by simulation based on a large amount of data.

[0065] Working principle of the invention:

[0066] A method for assessing substation concrete foundations involves collecting surface environmental parameters of the reinforced concrete foundation cap during operation. These parameters include chloride ion, sulfate ion, and carbonate ion concentrations. The thickness of the protective cap is also measured. The reinforced concrete foundation cap is located above three PHC pipe piles. A vibration measuring device is placed on the surface of the reinforced concrete foundation cap. The optimal frequency of the vibration measuring device is calibrated through testing. At the calibrated optimal frequency, the bearing capacity of the reinforced concrete foundation cap is dynamically detected and analyzed using the vibration measuring device. The bearing capacity deviation index Yz of the reinforced concrete foundation cap is calculated based on the maximum dynamic resilient modulus Ed and crack detection results. If Yz exceeds a preset deviation threshold, the bearing capacity of the reinforced concrete foundation cap is determined to be weak, generating a maintenance and reinforcement signal to alert management personnel to perform maintenance and reinforcement of the reinforced concrete foundation cap, ensuring the safe operation of the power grid.

[0067] Potential life correlation data of reinforced concrete foundations under different scenarios are collected as sample data. The potential life correlation data includes surface environment parameters, foundation cap thickness, and bearing pressure deviation index. Parameter optimization is performed on the sample data. The sample data is divided into training set, test set, and validation set according to a set ratio. Then, the training set, test set, and validation set are input into the BERT model to train the life assessment model. The measured surface environment parameters, foundation cap thickness, and bearing pressure deviation index are used as input data for the life assessment model to obtain the corresponding life prediction data of the reinforced concrete foundation. This improves prediction efficiency and accuracy, thereby improving regional decision-making efficiency.

[0068] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0069] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for evaluating concrete foundations of substations, characterized in that, Includes the following steps: Step 1: Collect surface environmental parameters of the reinforced concrete foundation, including chloride ion, sulfate ion and carbonate ion; at the same time, measure the thickness of the protective cap of the foundation. Step 2: A reinforced concrete foundation is located above three PHC pipe piles; the upper part of the PHC pipe piles is connected by the reinforced concrete foundation; a vibration measuring device is placed on the surface of the reinforced concrete foundation; the optimal frequency of the vibration measuring device is calibrated through testing. The vibration measuring device includes a hydraulic cylinder, a connecting shaft, tires, an ultrasonic probe, and a drive motor connected to the connecting shaft via an internal gear transmission; the piston of the hydraulic cylinder is connected to the connecting shaft, and tires are provided on both sides of the connecting shaft; Step 3: At the calibrated optimal frequency, the bearing capacity of the reinforced concrete foundation is dynamically tested and analyzed using a vibration measurement device. The specific testing and analysis process is as follows: S31: At the calibrated optimal frequency, start the drive motor to rotate the connecting shaft; measure the maximum dynamic spring modulus Ed at this frequency. S32: Divide the surface of the reinforced concrete foundation into n equal regions. Set up a plane coordinate system based on the foundation surface and mark the coordinates of the n regions as (Xn, Yn). Obtain the pressure values ​​of the n regions during dynamic bearing pressure testing and mark the pressure values ​​of the n regions as Yn. S33: Obtain the standard pressure value through the cloud server, then control the output pressure of the hydraulic cylinder to reach the preset standard pressure value, and use an ultrasonic probe to detect cracks on the surface of the bearing platform; S34: Based on the maximum dynamic resilient modulus Ed and crack detection results, the compressive performance of the reinforced concrete foundation is dynamically analyzed, and the compressive deviation index Yz of the reinforced concrete foundation is calculated; the specific calculation steps are as follows: The surface area of ​​the bearing platform where cracks appear is marked as Bv. The number of areas Bv is counted, and the proportion of areas Bv is obtained as Bz. The proportion of areas Bv is the ratio of the number of areas Bv to n. The pressure value corresponding to the appearance of cracks in area Bv is obtained and marked as Ybv. The pressure difference YL1 is calculated by comparing Ybv with the standard pressure value. The pressure difference YL1 is compared with the preset pressure difference threshold. The percentage of times YL1 > the preset pressure difference threshold is Lb1. When YL1 > the preset pressure difference threshold, the difference between YL1 and the preset pressure difference threshold is obtained and summed to obtain the pressure difference CZ. The bearing pressure deviation index Yz of the reinforced concrete foundation is calculated using the formula Yz=ƒ×Bz×(Lb1×a1+CZ×a2) / (Ed×a3), where a1, a2, and a3 are preset coefficient factors; and ƒ is a preset equilibrium coefficient. Step 4: Use the measured surface environment parameters, the thickness of the protective cap of the foundation, and the bearing pressure deviation index Yz as input data for the life assessment model to obtain the life prediction data of the corresponding reinforced concrete foundation. The specific steps for constructing the life assessment model are as follows: Potential life correlation data of reinforced concrete foundations under different scenarios were collected as sample data; potential life correlation data included surface environment parameters, foundation protective cap thickness and bearing pressure deviation index. The parameters of the sample data are optimized, including epoch optimization, batch size optimization and number of neurons optimization in sequence. The sample data is divided into training set, test set and validation set according to a set ratio. Then the training set, test set and validation set are input into the BERT model to train the life assessment model.

2. The method for evaluating concrete foundations of substations according to claim 1, characterized in that, The optimal frequency of the vibration measuring device is determined through testing. The specific steps are as follows: In the same filler, at the optimum moisture content, the relationship between the internal strength of concrete and the maximum dynamic resilient modulus Ed was measured by vibrating at different frequencies. The optimum frequency was determined by data fitting analysis. At the optimum frequency, the dispersion between strength and maximum dynamic resilient modulus Ed was minimized.

3. The method for evaluating concrete foundations of substations according to claim 1, characterized in that, Step S31 also includes: the connecting shaft drives the tires on both sides to rotate synchronously, and a belt is fitted on the side circumference of the reinforced concrete foundation. When the tires rotate, the friction between the tire surface and the belt surface drives the belt to run, so that while the tires are rotating at high speed, the foundation surface is stationary relative to the tires.

4. The method for evaluating concrete foundations of substations according to claim 1, characterized in that, in, The semantic extraction layer of the BERT model is a multi-layer bidirectional decoder with a Transformer encoder as the basic unit, which includes three parts: attention mechanism, layer normalization and residual connection, and feedforward neural network.

5. The method for evaluating concrete foundations of substations according to claim 1, characterized in that, The method further includes: comparing the pressure deviation index Yz with a preset deviation threshold; If Yz is greater than the preset deviation threshold, the reinforced concrete foundation is determined to have weak bearing capacity, and a maintenance and reinforcement signal is generated to remind management personnel to carry out maintenance and reinforcement of the reinforced concrete foundation.

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