Simulation method of seismic performance of fabricated bridge pier considering corrosion of reinforcement and grouting sleeve

Abstract

The application discloses a kind of considering steel bar and grouting sleeve corrosion assembly type pier seismic performance simulation method, belong to engineering structure technical field.The method is first calculated the corrosion initiation time of steel bar under the induction of chloride ion, and then determine the reduction diameter of steel bar after corrosion and the degradation law of yield strength;Quantify the deterioration of concrete mechanics performance simultaneously, obtain the time-varying compressive strength of cover and restrained concrete;For grouting sleeve, simulate the reduction process of its equivalent cross-sectional area, establish time-varying equivalent cross-sectional area, and calculate the yield force decay coefficient under the failure mode of steel bar fracture and non-steel bar fracture respectively, to determine the equivalent yield strength of corrosion grouting sleeve.Finally, execute the analysis instruction corresponding to the above steps in OpenSees software platform in turn, and according to the execution result, output the displacement-force hysteretic curve data of pier seismic performance.The method can effectively support the seismic performance evaluation and life prediction of assembly type concrete structure in corrosive environment.

Description

Technical Field

[0001] This invention belongs to the field of engineering structure technology, and in particular relates to a method for simulating the seismic performance of prefabricated bridge piers that takes into account the corrosion of steel bars and grouting sleeves. Background Technology

[0002] Grouting sleeve connections are a common connection method between precast components in precast concrete structures, with steel or cast iron sleeves being widely used due to their excellent mechanical properties. During the long-term service of prestressed concrete structures, the grouting sleeves and internal reinforcing steel inevitably face a chloride-corrosion environment, and the resulting corrosion poses a potential threat to the structure's seismic performance.

[0003] To address the aforementioned issues, scholars have conducted relevant experimental studies. For example, existing technologies have used pull-out tests to examine grouting sleeves, systematically investigating the effects of parameters such as corrosion degree, rebar eccentricity, and grouting sleeve dimensions on the failure modes and mechanical properties of grouting sleeves. The studies indicate that increased corrosion leads to a decrease in the load-bearing capacity and deformation capacity of the grouting sleeve, with crack load, yield load, and peak load all showing a gradual decreasing trend. Existing technologies have also conducted quasi-static tests on column base joints connected by grouting sleeves, showing that increased corrosion degree continuously weakens the joint's load-bearing capacity and energy dissipation capacity. Furthermore, existing technologies have also conducted time-varying pushover analysis under the coupled effects of chloride corrosion and freeze-thaw cycles on precast bridge piers connected by grouting sleeves.

[0004] However, existing research still has the following shortcomings: First, existing experimental data mainly focus on the mechanical property degradation patterns at the component level, and it is still difficult to systematically characterize the overall hysteretic behavior of precast bridge piers under the coupled effects of steel reinforcement corrosion and grouting sleeve corrosion. The mechanical property degradation caused by corrosion involves multiple levels of materials, connection interfaces, and components, and their mutual coupling mechanisms are complex and cannot be fully revealed by experimental methods alone.

[0005] Second, numerical simulation, as an important research tool, is not yet fully applied in the seismic performance analysis of precast bridge piers under corrosion. The key limiting factor is the lack of a constitutive model for the grouting sleeve material that can reflect the corrosion development over time, as well as the constitutive relationship of the connection interface under corrosion, which makes it difficult for existing numerical methods to accurately simulate the evolution of the mechanical response of the structure during the corrosion process.

[0006] Third, unlike cast-in-place bridge piers, precast concrete bridge piers exhibit significant differences in corrosion damage between the grouting sleeve area and the ordinary concrete area. Coupled with the spatial non-uniformity of the corrosive environment, this results in complex and non-uniform mechanical performance degradation characteristics along the height direction. This spatial difference further increases the difficulty of refined simulation, making it difficult for existing research methods to effectively track the seismic performance evolution of precast bridge piers throughout their entire life cycle.

[0007] In summary, there is an urgent need to develop a numerical simulation method that can comprehensively consider the corrosion effects of steel bars and grouting sleeves and reflect the non-uniform mechanical property degradation of precast bridge piers, so as to support the seismic performance assessment and life prediction of precast concrete structures in corrosive environments. Summary of the Invention

[0008] The purpose of this invention is to address the technical problems existing in the prior art by conducting a numerical simulation study on precast concrete bridge piers (precast concrete components, PC components) affected by corrosion, and to propose a method for simulating the seismic performance of precast bridge piers that considers the corrosion of reinforcing bars and grouting sleeves.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a method for simulating the seismic performance of prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves, comprising the following steps: S1: Calculate the parameters for the onset time of chloride ion-induced steel corrosion based on chloride ion diffusion theory. ; S2: Based on the relationship between corrosion current density and time, calculate the reduced diameter of the reinforcing bar at a certain moment after corrosion. This allows for the calculation of the time-varying cross-sectional area of ​​the corroded reinforcing steel and the grouting sleeve. and ; S3: Reinforcing steel mass loss rate over time Calculate the yield strength of the steel reinforcement after corrosion. ; S4: For both protective concrete and confined concrete, quantify the degradation of compressive strength caused by corrosion, and calculate the compressive strength of the protective concrete after corrosion. and the compressive strength of corroded concrete ; S5: Simplify the grouting sleeve of the composite section into a steel bar with an equivalent cross-sectional area, and calculate the time-varying equivalent cross-sectional area of ​​the grouting sleeve. ; S6: Obtain two failure modes of the corrosion grouting sleeve, including a rebar fracture failure mode and a non-rebar fracture failure mode; calculate the yield strength attenuation coefficient under the rebar fracture failure mode respectively. and the yield strength attenuation coefficient in the non-reinforcement fracture failure mode According to the yield strength attenuation coefficient in the described steel reinforcement fracture failure mode and the yield strength attenuation coefficient in the non-reinforcement fracture failure mode Determine the equivalent yield strength of the corrosion grouting sleeve as a function of time. ; S7: In the OpenSees software platform, execute the analysis commands corresponding to steps S1 to S6 sequentially, and based on the key parameters used to characterize the degree of steel reinforcement corrosion and grouting sleeve corrosion in the execution results of steps S2 to S6, i.e. , , , , and Output displacement-force hysteresis curve data of bridge pier seismic resistance.

[0010] Furthermore, in step S1, the parameter for the onset time of steel bar corrosion... The calculation formula is: ; in The thickness of the protective concrete layer; The environmental factor is set to 0.942. The experimental method coefficient is taken as 0.832; The maintenance time correction factor is set to 1.0; For reference time period The diffusion coefficient; It is the Gaussian error function; The aging coefficient; The critical chloride ion concentration; This represents the chloride ion concentration on the concrete surface.

[0011] Furthermore, in step S2, the reduced diameter of the reinforcing bar at a certain moment after corrosion... The calculation formula is: ; in The original diameter of the reinforcing bar; This represents the corrosion current density. express time.

[0012] Furthermore, in step S3, the yield strength of the corroded steel bar... The calculation formula is: ; in, This indicates the yield strength of the uncorroded steel reinforcement. The percentage of steel reinforcement loss over time. , This represents the cross-sectional area of ​​the uncorroded reinforcing steel. This represents the time-varying cross-sectional area of ​​the corroded steel reinforcement. .

[0013] Furthermore, in step S4, the compressive strength of the corroded protective layer concrete... The calculation formula is: ; in and These are the compressive strengths of the original concrete and the concrete of the protective layer after corrosion, respectively. It is related to the roughness and diameter of the reinforcing steel. It is the peak strain of the uncorroded concrete; It is the average tensile strain of the cracked concrete. , This refers to the quantity of reinforcing bars in the pier on the compressed side. Indicates the width of the concrete cross-section; It refers to the width of cracks in concrete that changes over time. , , Indicates the average corrosion depth of concrete. This is the ratio of the steel bar radii. This is a dimensionless parameter with a value of 0.63. =1.41MPa; Represents the average tensile strength of concrete; The original diameter of the reinforcing bar; The thickness of the protective concrete layer; The compressive strength of the corroded confined concrete The calculation formula is: ; in, This indicates the compressive strength of the original concrete; This represents the effective lateral restraint stress borne by the concrete.

[0014] Furthermore, in step S5, the time-varying equivalent cross-sectional area of ​​the grouting sleeve... The calculation formula is: ; in and These are the elastic moduli of the grouting sleeve and the reinforcing bar, respectively. This refers to the time-varying cross-sectional area of ​​the grouting sleeve after corrosion. This represents the cross-sectional area of ​​the uncorroded reinforcing steel. , The time-varying residual outer diameter of the grouting sleeve after corrosion; This is the inner diameter of the grouting sleeve.

[0015] Furthermore, step S6 specifically includes: S61: Determine the time-varying equivalent yield strength of the grouting sleeve under corrosive conditions: Define the equivalent yield strength of a time-varying grouting sleeve. As shown in the following formula; ; in, The equivalent yield force of the grouting sleeve varies with time. The time-varying equivalent cross-sectional area of ​​the grouting sleeve; the equivalent yield force Determined by the following formula: ; in, The yield strength reduction factor, The equivalent yield force of the original grouting sleeve; S62: Calculate according to failure mode. and : When the failure mode is steel bar fracture, based on fundamental mechanics theory Corrosion of grouting sleeve Equivalent yield force at time Represented as: ;in The equivalent yield strength of the original grouting sleeve; and The yield strengths are those of the uncorroded and corroded grouting sleeves, respectively. This represents the cross-sectional area of ​​the uncorroded grouting sleeve; from this, the yield strength attenuation coefficient corresponding to the steel reinforcement fracture failure mode is derived. for: ; When the failure mode is a non-reinforcement fracture failure mode, the yield strength attenuation coefficient under the non-reinforcement fracture failure mode Represented as: ; in This represents the yield strength of the corrosion-grouted sleeve corresponding to the non-reinforced steel fracture mode. S63: The equivalent yield strength degradation unified model for corrosion grouting sleeves is constructed as follows: .

[0016] Compared with the prior art, the advantages of the present invention through the above design scheme are as follows: 1. Based on the fundamental mechanical theory in steps S1 to S5 and the phenomenological method in step S6 of the method described in this invention, the yield strength attenuation coefficient mentioned in step S6 is proposed. The analysis commands corresponding to steps S1 to S6 are executed sequentially in the OpenSees software platform. Based on the key parameters characterizing the corrosion degree of the reinforcing steel and the grouting sleeve in the execution results of steps S2 to S6, displacement-force hysteresis curve data of the bridge pier's seismic resistance are output for seismic simulation of the bridge pier. This yields a low-cost, high-precision numerical simulation method for the seismic performance of prefabricated bridge piers that considers the influence of corrosion of the reinforcing steel and the grouting sleeve. 2. By clearly distinguishing the differences in corrosion behavior between reinforcing bars and grouting sleeves, the seismic performance of prefabricated bridge piers with grouting sleeve connections can be predicted under any corrosive environment. Attached Figure Description

[0017] Figure 1 Flowchart of a simulation method for the seismic performance of prefabricated bridge piers, taking into account corrosion of reinforcing bars and grouting sleeves; Figure 2 The calculated and measured cyclic curves of specimen PC20 in this embodiment of the invention are shown. Detailed Implementation

[0018] To more clearly illustrate the present invention, it will be further described below with reference to the accompanying drawings. Those skilled in the art should understand that the specific description below is illustrative and not restrictive, and should not be construed as limiting the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains.

[0019] To avoid obscuring the essence of this invention, well-known methods, processes, and procedures are not described in detail.

[0020] like Figure 1 As shown, the seismic performance simulation method for prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves proposed in this invention includes: S1: Simulates the initiation time of steel corrosion, and calculates the parameters of the initiation time of chloride ion-induced steel corrosion. ; S2: Simulates the dimensions of the degraded reinforcing steel, calculating the reduced diameter of the steel at a certain moment after corrosion. ; S3: Simulates the degradation of the mechanical properties of reinforcing steel bars and calculates the yield strength of the steel bars after corrosion. ; S4: Quantify the degradation of concrete mechanical properties and calculate the compressive strength of the protective layer concrete after corrosion. and the compressive strength of corroded concrete ; S5: Simulate the reduction of the equivalent cross-sectional area of ​​the grouting sleeve, and calculate the time-varying equivalent cross-sectional area of ​​the grouting sleeve. ; S6: Quantify the mechanical properties of the grouting sleeve after corrosion, and calculate them specifically using formulas. and To calculate Finally obtained ,in This represents the yield strength attenuation coefficient under the fracture failure mode of steel reinforcement. This represents the yield strength attenuation coefficient in non-reinforcement fracture failure modes. This represents the equivalent yield force of the grouting sleeve. This represents the equivalent yield strength of the corrosion grouting sleeve as a function of time. S7: In the OpenSees software platform, execute the analysis commands corresponding to steps S1 to S6 sequentially, and based on the key parameters used to characterize the degree of steel reinforcement corrosion and grouting sleeve corrosion in the execution results of steps S2 to S6, i.e. , , , , and Output displacement-force hysteresis curve data of bridge pier seismic resistance.

[0021] Specifically, step S1 includes: calculating the chloride ion-induced steel reinforcement corrosion initiation time parameter based on chloride ion diffusion theory. .

[0022] In one specific embodiment, step S1 includes the following steps: S11: The initiation time parameter of chloride ion-induced steel corrosion is derived from formula (1).

[0023] (1); in The thickness of the protective concrete layer; The environmental factor is set to 0.942. The experimental method coefficient is taken as 0.832; The maintenance time correction factor is set to 1.0; It is the Gaussian error function; For reference time period ( The diffusion coefficient (=28 days); The aging coefficient; The critical chloride ion concentration; The chloride ion concentration on the concrete surface is calculated using formula (2): (2); in Water-cement ratio; Take 7.758.

[0024] Specifically, step S2 includes: calculating the reduced diameter of the reinforcing bar at a certain moment after corrosion based on the relationship between corrosion current density and time. This allows for the calculation of the time-varying cross-sectional area of ​​the corroded reinforcing steel and the grouting sleeve. and .

[0025] In one specific embodiment, step S2 includes the following steps: S21: Calculate the reduced diameter of the reinforcing bar at time using formula (3). .

[0026] (3); in The original diameter of the reinforcing bar; This represents the corrosion current density.

[0027] S22: Given the similar corrosion mechanisms of reinforcing bars and grouting sleeves, the results obtained in step S21... Capable of describing the time-varying residual outer diameter of corrosion grouting sleeves The time-varying cross-sectional areas of the corroded steel bars and the grouting sleeve were calculated using equations (4) and (5), respectively. and ; (4); (5); in The inner diameter is the grouting sleeve. Because the outer surface of the grouting sleeve acts as a barrier against chloride ion penetration, the corrosion of the inner wall of the grouting sleeve and the reinforcing steel encased in the internal grouting material can be disregarded.

[0028] Specifically, step S3 includes: based on the steel reinforcement mass loss rate changing over time. Calculate the yield strength of the steel reinforcement after corrosion. .

[0029] In one specific embodiment, step S3 includes the following steps: S31: The deterioration of the mechanical properties of steel bars is quantified by formula (6), including yield strength, ultimate strength and ultimate strain.

[0030] (6); (7); (8); in, and These represent the yield strength of uncorroded and corroded reinforcing bars, respectively. and These represent the ultimate strength of uncorroded and corroded reinforcing bars, respectively. and These correspond to the ultimate strain of uncorroded and corroded reinforcing bars, respectively. The steel reinforcement mass loss rate as a function of time is calculated using formula (9); (9).

[0031] Specifically, step S4 includes: quantifying the degradation of compressive strength caused by corrosion for both the protective concrete and the confined concrete, and calculating the compressive strength of the protective concrete after corrosion. and the compressive strength of corroded concrete .

[0032] In one specific embodiment, step S4 includes the following steps: S41: The compressive mechanical properties of the corrosion-damaged concrete protective layer are quantified by formula (10); (10); in and These are the compressive strengths of the original concrete and the concrete of the protective layer after corrosion, respectively. It is related to the roughness and diameter of the reinforcing steel. It is the peak strain of the uncorroded concrete. It is the average tensile strain of the cracked concrete, which is calculated by formula (11); (11); in This refers to the amount of reinforcing steel bars in the pier on the compressed side. This indicates the width of the concrete cross-section. It is the crack width of concrete that changes over time, which is predicted using formulas (12) and (13); (12); (13); in This represents the ratio of the average corrosion depth to the radius of the reinforcing bar. This is a dimensionless parameter with a value of 0.63. =1.41MPa. This represents the average tensile strength of the concrete. When the crack width reaches 1 mm, the concrete cover peels off, at which point... ;;

[0033] S42: For confined concrete, based on the existing Mander confined concrete model and considering the corrosion-induced confinement strength degradation effect, its compressive strength... Calculated using formula (14); (14); in This indicates the effective lateral restraint strength that the concrete can withstand.

[0034] Specifically, step S5 includes: simplifying the composite cross-section grouting sleeve into a steel bar with an equivalent cross-sectional area, and calculating the time-varying equivalent cross-sectional area of ​​the grouting sleeve. .

[0035] In one specific embodiment, step S5 includes the following steps: S51: Determine the mass loss rate of the corrosion grouting sleeve using equation (15) ; (15); in This indicates the cross-sectional area of ​​the uncorroded grouting sleeve.

[0036] S52: The grouting sleeve with a composite section is simplified to a steel bar with an equivalent cross-sectional area. The equivalent cross-sectional area of ​​the grouting sleeve is calculated using formula (16). The equivalent method can be seen from the relationship between the grouting sleeve and the reinforcing bar, and the cross-sectional areas of the two can be equivalent. (Sun WFHSW. Dynamic shear strength of precast connection with UHPC-based and traditional grouted sleeves: Test, simulation, and analytical formulas. Engineering Structures. 2025;323. Dynamic shear strength of precast connection with UHPC-based and traditional grouted sleeves: Test, simulation and analytical formulas

[32] Sun HSCYC. Seismic performance of precast multi-segment columns with grouted sleeves: Experimental and numerical investigations Engineering Structures. 2024;301 Seismic performance of precast multi-segment columns with grouted sleeves: Experimental and numerical investigations) (16); in and These are the elastic moduli of the grouting sleeve and the reinforcing bar, respectively.

[0037] Specifically, step S6 includes: obtaining two failure modes of the corrosion grouting sleeve, the two failure modes including a rebar fracture mode and a non-rebar fracture mode; and calculating the yield strength attenuation coefficient under the rebar fracture mode respectively. and the yield strength attenuation coefficient under the non-reinforced fracture mode According to the yield strength attenuation coefficient under the described steel reinforcement fracture mode and the yield strength attenuation coefficient under the non-reinforced fracture mode Determine the equivalent yield strength of the corrosion grouting sleeve as a function of time. .

[0038] In one specific embodiment, step S6 includes the following steps: S61: Defines the equivalent yield strength of a grouting sleeve that varies with time. As shown in formula (17); (17); in The equivalent yield force of the grouting sleeve as a function of time is calculated using equation (18): (18); in The yield strength reduction factor, The equivalent yield force of the original grouting sleeve; S62: Calculation and ; When the failure mode is steel bar fracture, the equivalent yield force of the grouting sleeve is derived using basic mechanics theory (formula (19)). At any given moment, the equivalent yield force of the corrosion grouting sleeve... Calculations are performed using formula (20); (19); (20); in The equivalent yield strength of the original grouting sleeve; and These represent the yield strengths of the uncorroded and corroded grouting sleeves, respectively. Based on formulas (18)-(20), the yield strength attenuation coefficients for the corresponding steel reinforcement fracture modes are derived. As shown in formula (21); (twenty one); When a failure occurs that is not a steel reinforcement fracture mode, the reduction factor is calculated using formula (22). .

[0039] (twenty two); in This represents the yield strength of the corrosion-grouted sleeve corresponding to the non-reinforced steel fracture mode.

[0040] S63: Based on formula (18), two failure modes of corrosion grouting sleeves are defined: steel bar fracture mode (the sleeve is reliably anchored, and the steel bar reaches its yield strength and then necking and fracture, which is a ductile ideal failure) and non-steel bar fracture mode (the steel bar does not yield and then interface slippage, grout splitting, sleeve failure or anchorage failure occurs, which is a brittle unsafe failure).

[0041] The influence mechanism of steel reinforcement fracture and non-steel reinforcement fracture on mechanical properties can be further expressed by the equivalent yield strength degradation model through formula (23); (twenty three).

[0042] Specifically, step S7 includes: sequentially executing the analysis commands corresponding to steps S1 to S6 in the OpenSees software platform, and based on the key parameters used to characterize the degree of steel reinforcement corrosion and the corrosion degree of the grouting sleeve in the execution results of steps S2 to S6, i.e. , , , , and Output displacement-force hysteresis curve data of bridge pier seismic resistance.

[0043] In one specific embodiment, step S7 includes the following steps: S71: In the OpenSees software platform, execute the analysis commands corresponding to steps S1 to S6 in sequence, and in response to the execution results of steps 1 to 6, output the displacement-force hysteresis curve data of the bridge pier seismic resistance; it should be noted that the displacement-force hysteresis curve (also known as the restoring force curve) is a closed curve used in structural engineering to describe the nonlinear relationship between force and displacement of a component or material under cyclic loading, and is widely used in seismic performance assessment, material constitutive modeling and structural health monitoring.

[0044] S72: In a specific embodiment, input the specific parameters of specimen PC20: ; This invention makes targeted improvements to the existing program instructions of the Opensees software platform. Specifically, by reconstructing and optimizing the key expressions and their corresponding parameters, a numerical model of prefabricated bridge piers capable of reflecting the effects of corrosion on reinforcing bars and grouting sleeves is constructed. This improvement is not a simple call to the original instructions or adjustment of parameters, but rather a substantial modification to the internal calculation logic and parameter passing method of the program based on the mechanical response mechanism under corrosion, thereby achieving effective simulation of the stress behavior of prefabricated bridge piers under the influence of corrosion.

[0045] S73: Numerical simulation of the seismic performance of prefabricated bridge piers was performed using a numerical model. The displacement-force hysteresis curves of the piers under seismic resistance were output, and the simulation results were finally obtained. The calculated and measured hysteresis curves of specimen PC20 were compared as follows: Figure 2 , Figure 2 The experimental and simulated curves of the PC20 specimen are compared. The numerical model accurately captures the nonlinear force-displacement relationship of the PC20 specimen, with a peak strength error of only 2.52%. The comparison shows that the method described in this patent has high accuracy.

Claims

1. A method for simulating the seismic performance of prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves, characterized in that, Includes the following steps: S1: Calculate the parameters for the onset time of chloride ion-induced steel corrosion based on chloride ion diffusion theory. ; S2: Based on the relationship between corrosion current density and time, calculate the reduced diameter of the reinforcing bar at a certain moment after corrosion. This allows for the calculation of the time-varying cross-sectional area of ​​the corroded reinforcing steel and the grouting sleeve. and ; S3: Reinforcing steel mass loss rate over time Calculate the yield strength of the steel reinforcement after corrosion. ; S4: For both protective concrete and confined concrete, quantify the degradation of compressive strength caused by corrosion, and calculate the compressive strength of the protective concrete after corrosion. and the compressive strength of corroded concrete ; S5: Simplify the grouting sleeve of the composite section into a steel bar with an equivalent cross-sectional area, and calculate the time-varying equivalent cross-sectional area of ​​the grouting sleeve. ; S6: Obtain two failure modes of the corrosion grouting sleeve, including a rebar fracture failure mode and a non-rebar fracture failure mode; calculate the yield strength attenuation coefficient under the rebar fracture failure mode respectively. and the yield strength attenuation coefficient in the non-reinforcement fracture failure mode ; Based on the yield strength attenuation coefficient of the aforementioned steel reinforcement fracture failure mode and the yield strength attenuation coefficient in the non-reinforcement fracture failure mode Determine the equivalent yield strength of the corrosion grouting sleeve as a function of time. ; S7: In the OpenSees software platform, execute the analysis commands corresponding to steps S1 to S6 sequentially, and based on the key parameters used to characterize the degree of steel reinforcement corrosion and grouting sleeve corrosion in the execution results of steps S2 to S6, i.e. , , , , and Output displacement-force hysteresis curve data of bridge pier seismic resistance.

2. The method for simulating the seismic performance of prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves according to claim 1, characterized in that, In step S1, the parameter for the onset time of steel corrosion. The calculation formula is: ； in The thickness of the protective concrete layer; The environmental factor is set to 0.

942. The experimental method coefficient is taken as 0.832; The maintenance time correction factor is set to 1.0; For reference time period The diffusion coefficient; It is the Gaussian error function; The aging coefficient; The critical chloride ion concentration; This represents the chloride ion concentration on the concrete surface.

3. The method for simulating the seismic performance of prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves according to claim 1, characterized in that, In step S2, the reduced diameter of the reinforcing bar at a certain moment after corrosion. The calculation formula is: ； in The original diameter of the reinforcing bar; This represents the corrosion current density. express time.

4. The method for simulating the seismic performance of prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves according to claim 1, characterized in that, In step S3, the yield strength of the corroded steel bar... The calculation formula is: ； in, This indicates the yield strength of the uncorroded steel reinforcement. The percentage of steel reinforcement loss over time. , This represents the cross-sectional area of ​​the uncorroded reinforcing steel. This represents the time-varying cross-sectional area of ​​the corroded steel reinforcement. .

5. The method for simulating the seismic performance of prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves according to claim 1, characterized in that, In step S4, the compressive strength of the corroded protective layer concrete... The calculation formula is: ； in and These are the compressive strengths of the original concrete and the concrete of the protective layer after corrosion, respectively. It is related to the roughness and diameter of the reinforcing steel. It is the peak strain of the uncorroded concrete; It is the average tensile strain of the cracked concrete. , This refers to the quantity of reinforcing steel bars in the pier on the compressed side. Indicates the width of the concrete cross-section; It refers to the width of cracks in concrete that changes over time. , , Indicates the average corrosion depth of concrete. This is the ratio of the steel bar radii. This is a dimensionless parameter with a value of 0.

63. =1.41MPa; Represents the average tensile strength of concrete; The original diameter of the reinforcing bar; The thickness of the protective concrete layer; The compressive strength of the corroded confined concrete The calculation formula is: ； in, This indicates the compressive strength of the original concrete; This represents the effective lateral restraint stress borne by the concrete.

6. The method for simulating the seismic performance of prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves according to claim 1, characterized in that, In step S5, the time-varying equivalent cross-sectional area of ​​the grouting sleeve... The calculation formula is: ； in and These are the elastic moduli of the grouting sleeve and the reinforcing bar, respectively. This refers to the time-varying cross-sectional area of ​​the grouting sleeve after corrosion. This represents the cross-sectional area of ​​the uncorroded reinforcing steel. , The time-varying residual outer diameter of the grouting sleeve after corrosion; This is the inner diameter of the grouting sleeve.

7. The method for simulating the seismic performance of prefabricated bridge piers considering corrosion of reinforcing bars and grouting sleeves according to claim 1, characterized in that, Step S6 specifically includes: S61: Determine the time-varying equivalent yield strength of the grouting sleeve under corrosive conditions: Define an equivalent yield strength of a time-varying grouting sleeve. As shown in the following formula; ； in, The equivalent yield force of the grouting sleeve varies with time. The time-varying equivalent cross-sectional area of ​​the grouting sleeve; the equivalent yield force Determined by the following formula: ； in, The yield strength reduction factor, The equivalent yield force of the original grouting sleeve; S62: Calculate according to failure mode. and : When the failure mode is steel bar fracture, based on fundamental mechanics theory Corrosion of grouting sleeve Equivalent yield force at time Represented as: ;in The equivalent yield strength of the original grouting sleeve; and The yield strengths are those of the uncorroded and corroded grouting sleeves, respectively. This represents the cross-sectional area of ​​the uncorroded grouting sleeve; from this, the yield strength attenuation coefficient corresponding to the steel reinforcement fracture failure mode is derived. for: ； When the failure mode is a non-reinforcement fracture failure mode, the yield strength attenuation coefficient under the non-reinforcement fracture failure mode Represented as: ； in This represents the yield strength of the corrosion-grouted sleeve corresponding to the non-reinforcement fracture mode; S63: The equivalent yield strength degradation unified model for corrosion grouting sleeves is constructed as follows: 。

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