A method and system for predicting the residual strength of anchor cables after corrosion

Abstract

This application relates to the field of mining anchoring technology, and provides a method and system for predicting the residual strength of anchor cables after corrosion. In this method, the corrosion influence parameters of the anchor cable in a corrosive environment are determined based on the changes in the physical parameters of the root wires constituting the anchor cable before and after corrosion. Based on the corrosion influence parameters and a pre-constructed residual strength model of the anchor cable after corrosion, the residual strength of the anchor cable after corrosion is predicted. Thus, by establishing the relationship between the residual irregular shape of the anchor cable after corrosion and its mechanical properties, the residual strength of the in-service anchor cable after corrosion can be predicted without conducting destructive pull-out tests. This provides a direct and reliable technical basis for the safety assessment and life prediction of in-service corroded anchor cables, and provides core support for the safe operation, remaining life prediction, and maintenance decisions of engineering structures.

Description

Technical Field

[0001] This application relates to the field of anchoring technology in underground mines, and in particular to a method and system for predicting the residual strength of anchor cables after corrosion. Background Technology

[0002] Anchor cable support in coal mines is a crucial method for controlling the surrounding rock in mine roadways. However, the complex underground environment of coal mines, with its high humidity, high salinity, methane gas, and groundwater, makes anchor cables highly susceptible to corrosion. Corrosion reduces the effective cross-sectional area of ​​the anchor cable and creates irregular corrosion pits on its surface, severely impacting its load-bearing capacity and service life, posing a significant threat to safe coal mine production. Summary of the Invention

[0003] The purpose of this application is to provide a method and system for predicting the residual strength of anchor cables after corrosion, so as to solve or alleviate the problems existing in the prior art.

[0004] To achieve the above objectives, this application provides the following technical solution: This application provides a method for predicting the residual strength of anchor cables after corrosion, including: Based on the composition of the anchor cable before and after corrosion The changes in the physical parameters of the steel wires were used to determine the corrosion impact parameters of the in-service anchor cables in a corrosive environment; among them, The value is a positive integer; the residual strength of the anchor cable after corrosion is predicted based on the corrosion influence parameters of the anchor cable and the pre-built residual strength model of the anchor cable after corrosion.

[0005] Preferably, the corrosion impact parameters include the corrosion damage factor of in-service anchor cables in corrosive environments. And based on the composition of the anchor cable before and after corrosion Based on the diameter of the steel wire, calculate the corrosion damage factor of the anchor cable. .

[0006] Preferably, according to the corrosion damage model: Calculate the corrosion damage factor of anchor cables In the formula, For the first component of the anchor cable The remaining diameter of the steel wire after corrosion; The initial diameter of the steel wires that make up the anchor cable; It is the ratio of the initial diameter of the central wire that makes up the anchor cable to the initial diameter of the outer wire that makes up the anchor cable.

[0007] Preferably, the corrosion impact parameter includes the corrosion correction factor for in-service anchor cables in corrosive environments. Furthermore, based on the equivalent corrosion pit parameters when the anchor cable is corroded and the composition of the anchor cable before and after corrosion... The cross-sectional area of ​​the steel wire is used to determine the corrosion correction factor for the corrosion state of the anchor cable. .

[0008] Preferably, according to the anchor cable corrosion coefficient model: Corrosion correction factor for determining the corrosion state of anchor cables ; In the formula, This represents the average depth of the equivalent corrosion pit when the anchor cable is corroded. The average width of the equivalent corrosion pit of the anchor cable; This is the corrosion attenuation coefficient; For the composition of anchor cables The remaining total cross-sectional area of ​​the steel wire after corrosion; For the composition of anchor cables The initial total cross-sectional area of ​​the steel wire.

[0009] Preferably, according to the formula: Calculate the components of the anchor cable The initial total cross-sectional area of ​​the steel wire and the components that make up the anchor cable The remaining total cross-sectional area of ​​the steel wire after corrosion ; In the formula, The initial diameter of the steel wires that make up the anchor cable; The diameter of the central steel wire that makes up the anchor cable before corrosion; For the first component of the anchor cable The cross-sectional area of ​​the steel wire after corrosion.

[0010] Preferably, based on the constructed residual strength model of the anchor cable after corrosion, and according to the corrosion damage factor of the anchor cable... Corrosion correction factor The initial tensile strength of the anchor cable is used to predict the residual strength of the anchor cable after corrosion.

[0011] Preferably, the residual strength model after anchor cable corrosion is as follows: In the formula, The residual strength of the anchor cable after corrosion. This represents the initial tensile strength of the anchor cable. Corrosion damage factor for anchor cables, This is the corrosion correction factor for the corrosion state of the anchor cable.

[0012] Preferably, based on the tensile strength of the individual steel wires constituting the anchor cable and the overall strength of the anchor cable... The initial total cross-sectional area of ​​the steel wire is used to determine the initial tensile strength of the anchor cable. .

[0013] This embodiment also provides a system for predicting the residual strength of anchor cables after corrosion. The system uses any of the above-described methods for predicting the residual strength of anchor cables after corrosion to predict the residual strength of in-service anchor cables in a corrosive environment. The system includes: The corrosion effect parameter unit is configured to be based on the composition of the anchor cable before and after corrosion. The changes in the physical parameters of the steel wires were used to determine the corrosion impact parameters of the in-service anchor cables in a corrosive environment; among them, It is a positive integer; The residual strength prediction unit is configured to predict the residual strength of the anchor cable after corrosion based on the corrosion influence parameters of the anchor cable and the pre-built residual strength model of the anchor cable after corrosion.

[0014] Beneficial effects: The method and system for predicting the residual strength of anchor cables after corrosion provided in this application embodiment are based on the composition of the anchor cables before and after corrosion. The changes in the physical parameters of the steel wire are used to determine the corrosion impact parameters of in-service anchor cables in corrosive environments. Based on the corrosion impact parameters of the anchor cable and a pre-constructed residual strength model after corrosion, the residual strength of the anchor cable after corrosion is predicted. Thus, by establishing the relationship between the residual irregular shape of the corroded anchor cable and its mechanical properties, the residual strength of in-service anchor cables after corrosion can be predicted without destructive pull-out tests. This provides a direct and reliable technical basis for the safety assessment and life prediction of in-service corroded anchor cables, and provides core support for the safe operation, remaining life prediction, and maintenance decisions of engineering structures. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figure 1 This is a flowchart illustrating a method for predicting the residual strength of an anchor cable after corrosion, according to some embodiments of this application. Figure 2 This is a schematic diagram of a corrosion anchor cable specimen provided according to some embodiments of this application; Figure 3 This is a schematic diagram of the structure of corrosion pits on the surface of an anchor cable according to an embodiment of this application; Figure 4 This is another structural schematic diagram of corrosion pits on the surface of an anchor cable according to an embodiment of this application; Figure 5This is a schematic diagram of a system for predicting the residual strength of an anchor cable after corrosion, provided according to some embodiments of this application. Detailed Implementation

[0016] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will understand that modifications and variations can be made to the present application without departing from the scope or spirit of the present application. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention should fall within the scope of protection of the embodiments of the present invention.

[0017] Currently, the assessment of anchor cable strength after corrosion largely relies on empirical judgment or destructive testing, lacking a scientific, accurate, and non-destructive method for predicting residual strength. Therefore, this embodiment provides a method for predicting the residual strength of corroded anchor cables, primarily applied to engineering structures such as underground roadways reinforced with prestressed anchor cables. It addresses the problem of localized or uniform corrosion of anchor cables during long-term service due to environmental erosion (such as chloride ions, moisture, and stress corrosion), leading to a significant reduction in ultimate bearing capacity. Through a convenient and low-cost method for assessing the residual strength of corroded anchor cables, it provides core support for the safe operation, remaining service life prediction, and maintenance decisions of engineering structures.

[0018] like Figures 1 to 4 As shown, the method for predicting the residual strength of the corroded anchor cable includes: Step S101: Based on the composition of the anchor cable before and after corrosion... The changes in the physical parameters of the steel wire were used to determine the corrosion impact parameters of the in-service anchor cable in a corrosive environment.

[0019] Typically, mining anchor cables are made by twisting multiple outer steel wires around a central steel wire. Specifically, the anchor cable usually consists of 3, 7, or 19 wires; here, we'll use... To illustrate, an anchor cable is made of 7 steel wires twisted together, that is, it is made by twisting 6 outer steel wires around 1 central steel wire.

[0020] In this embodiment, random sampling is conducted in areas of severe anchor cable corrosion in underground coal mines, and a cutting tool is used to cut the exposed ends of the selected anchor cables. Corroded anchor cable specimens were prepared, and the deformed area of ​​the specimens was cut off at the cut end using a metal cutter in the laboratory, ensuring that the cut surface of the corroded anchor cable specimens was flat.

[0021] After being cut and flattened, the anchor cable samples were acid-washed to remove rust, making the morphological characteristics of the corroded anchor cable samples clearer. Then, the acid-washed corroded anchor cable samples were observed using a microscope and a 3D profilometer to obtain physical parameters such as the depth, width, and distribution of corrosion pits. Furthermore, the components of the anchor cable were analyzed. The remaining dimensions of the steel wire after corrosion were measured.

[0022] Then, based on the composition of the anchor cable before and after corrosion... Based on the diameter of the steel wire, calculate the corrosion damage factor of the anchor cable. ; and, based on the equivalent corrosion pit parameters of the anchor cable when it is corroded and the composition of the anchor cable before and after corrosion. The cross-sectional area of ​​the steel wire is used to determine the corrosion correction factor for the corrosion state of the anchor cable. .

[0023] In a specific example, according to the constructed corrosion damage model: Calculate the corrosion damage factor of in-service anchor cables in a corrosive environment. In the formula, For the first component of the anchor cable The remaining diameter of the steel wire after corrosion; The initial diameter of the steel wires that make up the anchor cable; It is the ratio of the initial diameter of the central wire that makes up the anchor cable to the initial diameter of the outer wire that makes up the anchor cable.

[0024] At the same time, according to the anchor cable composition of the anchor cable The diameter of the steel wire before and after corrosion determines the composition of the anchor cable before and after corrosion. The cross-sectional area of ​​the steel wire. Specifically, according to the formula: Determine the components of the anchor cable The cross-sectional area of ​​the steel wire before corrosion; where, This refers to the cross-sectional area of ​​the single outer steel wire that makes up the anchor cable before corrosion. The cross-sectional area of ​​the central steel wire that makes up the anchor cable before corrosion. The diameter of the central steel wire that makes up the anchor cable before corrosion. .

[0025] According to the formula: Determine the components of the anchor cable The cross-sectional area of ​​the steel wire after corrosion; where, For the first component of the anchor cable The cross-sectional area of ​​the steel wire after corrosion. For the first component of the anchor cable The remaining diameter of the steel wire after corrosion. It should be noted that this refers to the remaining diameter of the constituent steel wires (including the outer and center wires) of the in-service anchor cable after corrosion. It was measured in the laboratory using a micrometer.

[0026] Furthermore, the cross-sectional area of ​​in-service anchor cables before and after corrosion in corrosive environments is as follows: In the formula, For the composition of anchor cables The initial total cross-sectional area of ​​the steel wire before corrosion; For the composition of anchor cables The remaining total cross-sectional area of ​​the steel wire after corrosion.

[0027] In the corrosive environment of underground coal mines, corrosion pits form on the surface of in-service anchor cables due to corrosion. These pits are typically ellipsoidal in shape, leading to stress concentration and significantly impacting the strength of the anchor cables. For an ideal elliptical corrosion pit, the stress concentration factor is... for: In the formula, For the ideal depth of an elliptical corrosion pit, The ideal depth of an elliptical corrosion pit is the radius of curvature at its bottom. However, the complex morphology of anchor cable corrosion pits in underground coal mines makes it difficult to accurately measure the ideal depth of such pits. and ideal radius of curvature In this embodiment, the corrosion pits of the in-service anchor cable affected by corrosion are represented as semi-ellipses. The corroded anchor cable samples after acid washing are observed using a microscope and a 3D profilometer to obtain physical parameters such as the depth, width, and distribution of the corrosion pits. Furthermore, an anchor cable corrosion coefficient model is constructed: Corrosion correction factor for determining the corrosion state of anchor cables In the formula, This represents the average depth of the equivalent corrosion pit when the anchor cable is corroded. The average width of the equivalent corrosion pit when the anchor cable is corroded is the equivalent major axis of the corrosion pit as a semi-ellipse. is the corrosion attenuation coefficient. Wherein, the average depth of the equivalent corrosion pit is... The average width of the equivalent corrosion pit The larger the ratio, the sharper the corrosion pit, the greater the cross-sectional area damage caused by corrosion, the smaller the corrosion correction coefficient, and the greater the weakening effect of corrosion on the anchor cable strength.

[0028] Step S102: Based on the corrosion influence parameters of the anchor cable and the pre-constructed residual strength model of the anchor cable after corrosion, predict the residual strength of the anchor cable after corrosion.

[0029] In this embodiment, based on the constructed residual strength model of anchor cable after corrosion, and according to the corrosion damage factor of the anchor cable... Corrosion correction factor The initial tensile strength of the anchor cable is used to predict the residual strength of the anchor cable after corrosion. Specifically, the tensile strength of the in-service anchor cable before corrosion treatment is considered. It is related to the initial tensile strength of the individual steel wires that make up the anchor cable, specifically, according to the formula: Determine the tensile strength of in-service anchor cables before corrosion treatment. In the formula, This represents the initial tensile strength of a single steel wire that makes up the anchor cable.

[0030] Furthermore, the residual strength model of the anchor cable after corrosion was constructed: Residual strength of in-service anchor cables after corrosion in corrosive environments Corrosion correction factors for different types of anchor cables Corrosion weakening coefficient The corrosion attenuation coefficient varies depending on the type of anchor cable. In this embodiment, the corrosion attenuation coefficient of the same type of anchor cable is obtained by inversion using the measured physical parameters of the corrosion pits and the corresponding measured residual strength of the corrosion anchor cable sample. Furthermore, the corrosion attenuation coefficient is obtained through nonlinear least squares fitting inversion. To enable the prediction of the residual strength of in-service anchor cables in corrosive environments.

[0031] Therefore, by linking the residual irregular shape of the anchor cable after corrosion with its mechanical properties, the residual strength of the in-service anchor cable after corrosion can be predicted without conducting destructive pull-out tests on the anchor cable. This provides a direct and reliable technical basis for the safety assessment and life prediction of in-service corroded anchor cables, and provides core support for the safe operation, remaining life prediction and maintenance decision-making of engineering structures.

[0032] like Figure 5 As shown, this embodiment also provides a system for predicting the residual strength of anchor cables after corrosion. The system uses any of the above embodiments' methods for predicting the residual strength of anchor cables after corrosion in a corrosive environment to predict the residual strength of in-service anchor cables after corrosion. The system includes: Corrosion influence parameter unit 501 is configured to be based on the composition of the anchor cable before and after corrosion. The changes in the physical parameters of the steel wires were used to determine the corrosion impact parameters of the in-service anchor cables in a corrosive environment; among them, It is a positive integer; The residual strength prediction unit 502 is configured to predict the residual strength of the anchor cable after corrosion based on the corrosion influence parameters of the anchor cable and the pre-built residual strength model of the anchor cable after corrosion.

[0033] The anchor cable residual strength prediction system provided in this embodiment can realize the steps and process of the anchor cable residual strength prediction method after corrosion in any of the above embodiments, and achieve the same technical effect, which will not be described in detail here.

[0034] In the description of this invention, it should be understood that the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0035] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for predicting the residual strength of an anchor cable after corrosion, characterized in that, include: Based on the composition of the anchor cable before and after corrosion The changes in the physical parameters of the steel wires were used to determine the corrosion impact parameters of the in-service anchor cables in a corrosive environment; among them, It is a positive integer; Based on the corrosion influence parameters of the anchor cable and the pre-constructed residual strength model of the anchor cable after corrosion, the residual strength of the anchor cable after corrosion is predicted.

2. The method according to claim 1, characterized in that, Corrosion-affecting parameters include corrosion damage factors of in-service anchor cables in corrosive environments. And based on the composition of the anchor cable before and after corrosion Based on the diameter of the steel wire, calculate the corrosion damage factor of the anchor cable. .

3. The method according to claim 2, characterized in that, According to the corrosion damage model: Calculate the corrosion damage factor of anchor cables ; In the formula, For the first component of the anchor cable The remaining diameter of the steel wire after corrosion; The initial diameter of the steel wires that make up the anchor cable; It is the ratio of the initial diameter of the central wire that makes up the anchor cable to the initial diameter of the outer wire that makes up the anchor cable.

4. The method according to claim 1, characterized in that, Corrosion-affecting parameters include the corrosion correction factor for in-service anchor cables in corrosive environments. Furthermore, based on the equivalent corrosion pit parameters when the anchor cable is corroded and the composition of the anchor cable before and after corrosion... The cross-sectional area of ​​the steel wire is used to determine the corrosion correction factor for the corrosion state of the anchor cable. .

5. The method according to claim 4, characterized in that, According to the anchor cable corrosion coefficient model: Corrosion correction factor for determining the corrosion state of anchor cables ; In the formula, The average depth of the equivalent corrosion pit when the anchor cable is corroded. The average width of the equivalent corrosion pit in the anchor cable; This is the corrosion attenuation coefficient; For the composition of anchor cables The remaining total cross-sectional area of ​​the steel wire after corrosion; For the composition of anchor cables The initial total cross-sectional area of ​​the steel wire.

6. The method according to claim 5, characterized in that, According to the formula: Calculate the components of the anchor cable The initial total cross-sectional area of ​​the steel wire and the components that make up the anchor cable The remaining total cross-sectional area of ​​the steel wire after corrosion ; In the formula, The initial diameter of the steel wires that make up the anchor cable; The diameter of the central steel wire that makes up the anchor cable before corrosion; For the first component of the anchor cable The cross-sectional area of ​​the steel wire after corrosion.

7. The method according to claim 1, characterized in that, Based on the constructed residual strength model of anchor cable after corrosion, and according to the corrosion damage factor of anchor cable... Corrosion correction factor The initial tensile strength of the anchor cable is used to predict the residual strength of the anchor cable after corrosion.

8. The method according to claim 7, characterized in that, The residual strength model for anchor cables after corrosion is as follows: In the formula, The residual strength of the anchor cable after corrosion. This represents the initial tensile strength of the anchor cable. Corrosion damage factor for anchor cables, This is the corrosion correction factor for the corrosion state of the anchor cable.

9. The method according to claim 8, characterized in that, Based on the tensile strength of the individual steel wires that make up the anchor cable and the overall strength of the anchor cable... The initial total cross-sectional area of ​​the steel wire is used to determine the initial tensile strength of the anchor cable. .

10. A system for predicting the residual strength of corroded anchor cables, characterized in that, The method for predicting the residual strength of anchor cables after corrosion, as described in any one of claims 1-9, is used to predict the residual strength of in-service anchor cables after corrosion in a corrosive environment. The system comprises: The corrosion effect parameter unit is configured to be based on the composition of the anchor cable before and after corrosion. The changes in the physical parameters of the steel wires were used to determine the corrosion impact parameters of the in-service anchor cables in a corrosive environment; among them, It is a positive integer; The residual strength prediction unit is configured to predict the residual strength of the anchor cable after corrosion based on the corrosion influence parameters of the anchor cable and the pre-built residual strength model of the anchor cable after corrosion.

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