Quantitative evaluation method and system for removal effect of free iron oxide in red clay

Abstract

The invention relates to the technical field of engineering materials, and discloses a method and system for quantitatively evaluating the removal effect of free iron oxide in red clay, and the method comprises the following steps: carrying out soil sample pretreatment on a to-be-treated sample to obtain a pretreated sample; free iron oxide in the pretreated sample is removed through a free iron oxide removal step to obtain a removed treated sample, and the content of free iron oxide in the removed treated sample is measured by using an XRF test; carrying out dynamic performance calculation on the unprocessed sample, the completely processed sample and the incompletely processed sample to obtain a dynamic resilience modulus attenuation degree, a cumulative plastic strain attenuation degree and a cumulative strain rate attenuation degree; and quantitatively evaluating the removal effect of the free iron oxide in the red clay according to the dynamic resilience modulus attenuation degree, the cumulative plastic strain attenuation degree and the cumulative strain rate attenuation degree. The method solves the problems that the removal rate of the free iron oxide cannot be accurately measured and quantitative evaluation on the influence of different removal rates of the free iron oxide on the dynamic performance of the red clay is lacked in an existing free iron oxide removal mode.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering materials, and particularly to a method and system for quantitatively evaluating the removal effect of free iron oxide in red clay. Background Art

[0002] When building highways in red clay areas, it is inevitable to use red clay as subgrade filler. However, while red clay has characteristics such as weak expansibility, low compressibility, and strong structure, it also has disadvantages such as high water content, high plasticity index, and low strength, which are determined by iron oxide and clay minerals in the red clay. In hot, humid, and rainy areas, the groundwater level rises and falls repeatedly, causing the loss of free iron oxide between red clay particles and weakening the cementation effect, reducing the bearing capacity of the red clay subgrade. In addition, under the long-term action of traffic dynamic loads, cumulative deformation occurs in the subgrade, seriously affecting driving safety and comfort. However, at present, there is little understanding of the influence of microscopic cementation structure characteristics (such as free iron oxide content) on the dynamic properties of red clay under cyclic dynamic loads, resulting in engineering diseases such as uneven deformation of the subgrade, cracking of the road surface, and deformation of the slope. Therefore, it is necessary to compare the influence of free iron oxide content on the deformation characteristics of red clay. At present, traditional methods for removing free iron oxide (soaking method, permeation method) have problems such as slow treatment time, complex steps, and low removal amount, and existing methods rarely measure the content of removed free iron oxide and cannot determine the effectiveness of the test method. It can be seen that the existing methods for removing free iron oxide cannot accurately measure the removal rate of free iron oxide and lack a quantitative evaluation of the influence of different free iron oxide removal rates on the dynamic performance of red clay. Summary of the Invention

[0003] The present invention provides a method and system for quantitatively evaluating the removal effect of free iron oxide in red clay to solve the problem that the existing methods for removing free iron oxide cannot accurately measure the removal rate of free iron oxide and lack a quantitative evaluation of the influence of different free iron oxide removal rates on the dynamic performance of red clay.

[0004] To achieve the above object, the present invention is realized through the following technical solutions: In the first aspect, the present invention provides a method for quantitatively evaluating the removal effect of free iron oxide in red clay, including: Dividing the obtained target red clay into a sample to be treated and an untreated sample, and performing soil sample pretreatment on the sample to be treated to obtain a pretreated sample; Removing free iron oxide in the pretreated sample through a free iron oxide removal step to obtain a removed and treated sample, and measuring the content of free iron oxide in the removed and treated sample by using X-ray fluorescence spectrometry; Repeat the free iron oxide removal step for the treated sample until the free iron oxide content in the treated sample measured by X-ray fluorescence spectrometry is 0. Take the treated sample with a free iron oxide content of 0 as the completely treated sample, and take the removed sample with a non-zero free iron oxide content as the incompletely treated sample; Perform dynamic performance calculations on the untreated sample, the completely treated sample, and the incompletely treated sample to obtain the first dynamic resilient modulus, the first cumulative plastic strain, and the first cumulative strain rate corresponding to the untreated sample, obtain the second dynamic resilient modulus, the second cumulative plastic strain, and the second cumulative strain rate corresponding to the completely treated sample, and obtain the third dynamic resilient modulus, the third cumulative plastic strain, and the third cumulative strain rate corresponding to the incompletely treated sample; Determine the attenuation degree of the dynamic resilient modulus based on the first dynamic resilient modulus, the second dynamic resilient modulus, and the third dynamic resilient modulus, determine the attenuation degree of the cumulative plastic strain based on the first cumulative plastic strain, the second cumulative plastic strain, and the third cumulative plastic strain, and determine the attenuation degree of the cumulative strain rate based on the first cumulative strain rate, the second cumulative strain rate, and the third cumulative strain rate; Quantitatively evaluate the removal effect of free iron oxide in the red clay according to the attenuation degree of the dynamic resilient modulus, the attenuation degree of the cumulative plastic strain, and the attenuation degree of the cumulative strain rate.

[0005] Optionally, the pretreatment of the soil sample for the sample to be treated to obtain a pretreated sample includes: Add a sodium citrate solution and a sodium bicarbonate solution to the sample to be treated and stir, and then add solid sodium dithionite to the stirred sample and stir again to obtain a pretreated sample.

[0006] Optionally, the free iron oxide removal step includes: Place the pretreated sample in an electrolytic cell with a graphite anode and a copper rod cathode and apply a rated DC voltage to the electrolytic cell; Wash the electrolyzed pretreated sample with distilled water until there is no black-brown precipitate in the supernatant to obtain a treated sample, and dry the treated sample; Screen the dried sample with a sieve, and take the part that passes through the sieve as the removed and treated sample after the free iron oxide removal step.

[0007] Optionally, taking the removed sample with a non-zero free iron oxide content as the incompletely treated sample includes: Starting from the first free iron oxide removal step, after each free iron oxide removal step, divide the obtained sample into a sample to be further treated and a sample not to be further treated; The sample that continues to be processed is used for the next free iron oxide removal step, and the sample that does not continue to be processed is used as an incompletely processed sample; The pretreated sample undergoes N free iron oxide removal steps to obtain a removed sample with a free iron oxide content of 0, thereby obtaining N-1 incompletely treated samples.

[0008] Optionally, the performing of dynamic performance calculation on the unprocessed sample, the completely processed sample, and the incompletely processed sample includes: humidifying the untreated sample, the completely treated sample and the incompletely treated sample to obtain the humidified untreated sample, the humidified completely treated sample and the humidified incompletely treated sample; The dynamic performance of the untreated sample after humidification is calculated to obtain the first dynamic rebound modulus, the first cumulative plastic strain and the first cumulative strain rate corresponding to the untreated sample, and the calculation satisfies the following relationship: ; ; Where, M R1 is the first dynamic rebound modulus, σ d is the dynamic stress amplitude applied by the dynamic triaxial apparatus, ε r1 is the first accumulated plastic strain of the sample, is the first cumulative strain rate, ε pi and ε pi+1 The vibration times are N i and N i+1 The corresponding accumulated plastic strain, N i and N i+1 To load i Times and loads i +1 time; The dynamic performance of the fully treated sample after humidification was calculated to obtain the second dynamic rebound modulus, the second cumulative plastic strain and the second cumulative strain rate corresponding to the untreated sample. The calculation satisfies the following relationship: ; ; Where, M R2 is the second dynamic rebound modulus, ε r2 is the second accumulated plastic strain of the sample, is the second cumulative strain rate; The dynamic performance of the incompletely treated sample after humidification is calculated to obtain the third dynamic resilient modulus, the third cumulative plastic strain, and the third cumulative strain rate corresponding to the untreated sample, and their calculations satisfy the following relational expressions: ; ; In the formula, M R3 is the third dynamic resilient modulus, ε r3 is the third cumulative plastic strain of the sample, is the third cumulative strain rate.

[0009] Optionally, the calculation of the attenuation degree of the dynamic resilient modulus satisfies the following relational expression: ; In the formula, P M is the attenuation degree of the dynamic resilient modulus, M R is the dynamic resilient modulus of the red clay without removing free iron oxide, M t is the dynamic resilient modulus of the red clay with the free iron oxide removal rate of t , M N is the dynamic resilient modulus of the red clay with the complete removal rate of free iron oxide; The calculation of the attenuation degree adapted to the cumulative plastic strain satisfies the following relational expression: ; In the formula, P ε is the attenuation degree of the cumulative plastic strain, ε t is the cumulative plastic strain of the red clay when the free iron oxide removal rate is t , ε R is the cumulative plastic strain of the red clay without removing free iron oxide, ε N is the cumulative plastic strain of the red clay with the complete removal rate of free iron oxide; The calculation of the attenuation degree of the cumulative strain rate satisfies the following relational expression: ; In the formula, P v is the attenuation degree of the cumulative strain rate, V t is the cumulative strain rate of the red clay with the free iron oxide removal rate of t , V R is the cumulative strain rate of the red clay without removing free iron oxide, VN The cumulative strain rate of red clay for the complete removal rate of free iron oxide.

[0010] Optionally, the quantitative evaluation of the removal effect of free iron oxide in red clay according to the dynamic resilient modulus attenuation degree, the cumulative plastic strain attenuation degree, and the cumulative strain rate attenuation degree includes: Compare the magnitudes of the dynamic resilient modulus attenuation degree, the cumulative plastic strain attenuation degree, and the cumulative strain rate attenuation degree, and take the maximum value among the three of the dynamic resilient modulus attenuation degree, the cumulative plastic strain attenuation degree, and the cumulative strain rate attenuation degree; When 0% ≤ P max ≤ 25%, the structural damage degree of the red clay is low, and the dynamic performance is in a stable state; When 25% ≤ P max ≤ 50%, the structural damage degree of the red clay is medium, and the dynamic performance is in a critical state; When 50% ≤ P max ≤ 100%, the structural damage degree of the red clay is high, and the dynamic performance is in an unstable state; Wherein, P max is the maximum value among the three of the resilient modulus attenuation degree, the cumulative plastic strain attenuation degree, and the cumulative strain rate attenuation degree.

[0011] In a second aspect, an embodiment of the present application provides a quantitative evaluation system for the removal effect of free iron oxide in red clay, including a processor and a memory; The memory is used to store a computer program; The processor is used to implement any of the method steps in the first aspect when executing the program stored on the memory.

[0012] Beneficial effects: The quantitative evaluation method for the removal effect of free iron oxide in red clay provided by the present invention uses sodium dithionite, sodium citrate, and sodium bicarbonate as treatment agents, which can efficiently destroy the colloidal structure of free iron oxide, achieve the rapid removal of free iron oxide through electric field-driven redox, quantitatively measure the removal rate of free iron oxide of different red clay soil samples through X-ray fluorescence spectrometry, solves the problem that the existing method cannot accurately measure the removal rate of free iron oxide, this method is simple to operate, has a short test period, is suitable for large-scale treatment, and evaluates the dynamic performance of specimens with different free iron oxide contents through dynamic triaxial tests, and can accurately analyze the influence of free iron oxide on the mechanical properties of red clay. Description of the drawings

[0013] Figure 1Flow chart of the quantitative evaluation method for the removal effect of free iron oxide in red clay according to the preferred embodiment of the present invention; Figure 2 Schematic diagram of the X-ray fluorescence spectroscopy test results according to the preferred embodiment of the present invention; Figure 3 Schematic diagram of the dynamic resilient modulus results provided by the preferred embodiment of the present invention; Figure 4 Schematic diagram of the cumulative deformation results provided by the preferred embodiment of the present invention; Figure 5 Schematic diagram of the cumulative strain rate results provided by the preferred embodiment of the present invention. Detailed implementation manners

[0014] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without any creative work belong to the scope of protection of the present invention.

[0015] Unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meanings understood by those of ordinary skill in the art to which the present invention belongs. The "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, the terms such as "a" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to represent relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship also changes accordingly.

[0016] Embodiment 1 Please refer to Figure 1 , the embodiment of the present application provides a quantitative evaluation method for the removal effect of free iron oxide in red clay, including: Dividing the obtained target red clay into a sample to be processed and an unprocessed sample, and performing soil sample pretreatment on the sample to be processed to obtain a pretreated sample; Removing the free iron oxide in the pretreated sample through a free iron oxide removal step to obtain a removed and processed sample, and measuring the content of free iron oxide in the removed and processed sample by using an X-ray fluorescence (XRF) test; Repeat the free iron oxide removal step for the treated sample until the free iron oxide content in the treated sample measured by X-ray fluorescence spectroscopy is 0. Use the treated sample with a free iron oxide content of 0 as the fully treated sample, and use the treated sample with a non-zero free iron oxide content as the incompletely treated sample. Perform dynamic performance calculations on the untreated sample, fully treated sample, and incompletely treated sample to obtain the first dynamic resilient modulus, first cumulative plastic strain, and first cumulative strain rate corresponding to the untreated sample, the second dynamic resilient modulus, second cumulative plastic strain, and second cumulative strain rate corresponding to the fully treated sample, and the third dynamic resilient modulus, third cumulative plastic strain, and third cumulative strain rate corresponding to the incompletely treated sample. Determine the attenuation degree of the dynamic resilient modulus based on the first dynamic resilient modulus, second dynamic resilient modulus, and third dynamic resilient modulus, determine the attenuation degree of the cumulative plastic strain based on the first cumulative plastic strain, second cumulative plastic strain, and third cumulative plastic strain, and determine the attenuation degree of the cumulative strain rate based on the first cumulative strain rate, second cumulative strain rate, and third cumulative strain rate. Quantitatively evaluate the removal effect of free iron oxide in the red clay according to the attenuation degree of the dynamic resilient modulus, the attenuation degree of the cumulative plastic strain, and the attenuation degree of the cumulative strain rate.

[0017] The following describes different free iron oxide removal steps: I. Soil sample pretreatment Take 2 kg of air-dried and treated red clay and place it in a beaker. Add 4000 mL of 0.3 mol / L sodium citrate solution and 500 mL of 1 mol / L sodium bicarbonate solution and stir.

[0018] II. Chemical dissolution method Add 50 g of solid sodium dithionite, and continuously stir for 15 minutes to allow the mixed solution to react fully.

[0019] III. Electrochemical-driven redox Place the mixed solution in an electrolytic cell with a graphite anode and a copper rod cathode, and apply a rated DC voltage to the electrolytic cell. An oxidation reaction occurs in the anode region, destroying the structure of iron oxide; in the cathode region, a reduction reaction occurs, reducing Fe 3+ to Fe that is more easily reactive with chemical reagents. 2+ The electrochemical treatment lasts for 15 minutes.

[0020] IV. Washing and standing Wash the soil sample with distilled water until there is no black-brown precipitate in the supernatant, and then let it stand for 12 hours.

[0021] V. Detection and analysis After drying the red clay soil samples in an oven at 50 °C, the soil samples were passed through a 0.074 mm sieve, and the content of free iron oxide removed was determined by XRF test, obtaining the oxide content of red clay with a free iron oxide removal rate of 21%, as shown in the appendix Figure 2 shown

[0022] VI. Specimen preparation The red clay samples were passed through a 2 mm sieve. Under the condition that the spray rate of the atomizing humidifier was 200 mL / h, the red clay with a free iron oxide removal rate of 21% was atomized and humidified until the water content of the soil samples reached the optimum water content of 18.8%. Then, specimens with an optimum water content of 18.8% were prepared using a mold with a diameter of 50 mm and a height of 100 mm

[0023] VII. Mechanical property evaluation Dynamic triaxial tests were carried out on red clay specimens with an optimum water content of 18.8% and a free iron oxide removal rate of 21% under the conditions of a confining pressure of 30 kPa, a dynamic deviator stress of 30 kPa, and a consolidation ratio of 1.5 to analyze the effects of the free iron oxide content on the dynamic resilient modulus, plastic strain, and cumulative strain rate of red clay, as shown in the appendix Figure 3 shown. It was found that the attenuation degree of the dynamic resilient modulus of the red clay in this example was the largest, being P = 24%. The degree of structural damage of the red clay was low, and the dynamic performance was in a stable state. The corresponding cumulative plastic strain of its specimens was as shown in Figure 4 shown, while the cumulative strain rate was as shown in Figure 5 shown

[0024] Example 2 I. Soil sample pretreatment 2 kg of air-dried red clay was taken and placed in a beaker, and 4000 mL of 0.3 mol / L sodium citrate solution and 500 mL of 1 mol / L sodium bicarbonate solution were added and stirred

[0025] II. Chemical dissolution method 50 g of solid sodium dithionite was added, and continuous stirring was carried out for 15 minutes to make the mixed solution react fully

[0026] III. Electrochemical-driven redox The mixed solution was placed in an electrolytic cell with a graphite anode and a copper rod cathode, and a rated DC voltage was applied to the electrolytic cell. Oxidation reactions occurred in the anode region, destroying the structure of iron oxide; in the cathode region, reduction reactions occurred, reducing Fe 3+ to Fe that was more easily reactive with chemical reagents 2+ . The electrochemical treatment lasted for 15 minutes

[0027] IV. Washing and standing Wash the soil sample with distilled water until no black-brown precipitate appears in the supernatant, and then let it stand for 24 hours.

[0028] V. Detection and Analysis After drying the red clay soil sample in an oven at 50 °C, pass the soil sample through a 0.074 mm sieve, and determine the content of free iron oxide removed by XRF test to obtain the content of red clay oxide with a free iron oxide removal rate of 48%, as shown in the appendix Figure 2 as shown.

[0029] VI. Specimen Preparation Pass the red clay sample through a 2 mm sieve. Under the condition that the spray volume of the atomizing humidifier is 200 mL / h, atomize and humidify the red clay with a free iron oxide removal rate of 48% until the water content of the soil sample reaches the optimum water content of 18.8%. Then use a mold with a diameter of 50 mm and a height of 100 mm to prepare a specimen with an optimum water content of 18.8%.

[0030] VII. Mechanical Property Evaluation Carry out dynamic triaxial tests on the red clay specimens with an optimum water content of 18.8% and a free iron oxide removal rate of 48% under the conditions of a confining pressure of 30 kPa, a dynamic deviator stress of 30 kPa, and a consolidation ratio of 1.5, and analyze the effects of the free iron oxide content on the dynamic resilient modulus, plastic strain, and cumulative strain rate of red clay, as shown in the appendix Figure 3 as shown. It is found that the attenuation degree of the dynamic resilient modulus of the red clay in this example is the largest, which is P = 55%. The structural damage degree of the red clay is medium, and the dynamic performance is in a critical state. The corresponding cumulative plastic strain of its specimen is as shown in Figure 4 as shown, while the cumulative strain rate is as shown in Figure 5 as shown.

[0031] Example 3 I. Soil Sample Pretreatment Take 2 kg of air-dried red clay and place it in a beaker, add 4000 mL of 0.3 mol / L sodium citrate solution and 500 mL of 1 mol / L sodium bicarbonate solution and stir.

[0032] II. Chemical Dissolution Method Add 50 g of solid sodium dithionite and continuously stir for 15 minutes to make the mixed solution react fully.

[0033] III. Electrochemical Redox Driven by Electric Field Place the mixed solution in an electrolytic cell with a graphite anode and a copper rod cathode, and apply a rated DC voltage to the electrolytic cell. Oxidation reaction occurs in the anode region, destroying the structure of iron oxide; in the cathode region, reduction reaction occurs to reduce Fe 3+ to Fe that is more easily reactive with chemical reagents 2+。The electrochemical treatment lasts for 15 minutes.

[0034] IV. Washing and Static Placement Wash the soil sample with distilled water until there is no black-brown precipitate in the supernatant, and then let it stand for 48 hours.

[0035] V. Detection and Analysis After drying the red clay soil sample in an oven at 50 °C, pass the soil sample through a 0.074 mm sieve, and determine the content of free iron oxide removed through XRF test to obtain the content of red clay oxide with a free iron oxide removal rate of 79%, as shown in the appendix Figure 2 as shown.

[0036] VI. Specimen Preparation Pass the red clay sample through a 2 mm sieve. Under the condition that the spray volume of the atomizing humidifier is 2**00** milliliters per hour, atomize and humidify the red clay with a free iron oxide removal rate of 79% until the water content of the soil sample reaches the optimal water content of 18.8%, and then use a mold with a diameter of 50 mm and a height of 100 mm to prepare a specimen with an optimal water content of 18.8%.

[0037] VII. Mechanical Property Evaluation Conduct dynamic triaxial tests on the red clay specimens with an optimal water content of 18.8% and a free iron oxide removal rate of 79% under the conditions of a confining pressure of 30 kPa, a dynamic deviator stress of 30 kPa, and a consolidation ratio of 1.5, and analyze the effects of the free iron oxide content on the dynamic resilient modulus, plastic strain, and cumulative strain rate of the red clay, as shown in the appendix Figure 3 as shown. It is found that the attenuation degree of the dynamic resilient modulus of the red clay in this embodiment is the largest, which is P =82%, the degree of structural damage of the red clay is high, and the dynamic performance is in an unstable state. The corresponding cumulative plastic strain of its specimen is as shown in Figure 4 as shown, while the cumulative strain rate is as shown in Figure 5 as shown.

[0038] Example 4 I. Soil Sample Take 2 kg of air-dried red clay.

[0039] II. Detection and Analysis Pass the soil sample through a 0.074 mm sieve, and determine the free iron oxide content through XRF test to obtain the content of red clay oxide with a free iron oxide removal rate of 0%, as shown in the appendix Figure 2 as shown.

[0040] III. Specimen Preparation **Note**: There seems to be a mistake in the original text where "200 milliliters per hour" is written as "2**00** milliliters per hour". It has been corrected in the translation.The red clay sample is sieved through a 2 mm sieve, and under the condition that the spray volume of the atomizing humidifier is 200 ml / h, the red clay with a free iron oxide removal rate of 0% is atomized and humidified until the water content of the soil sample reaches the optimum water content of 18.8%. Then, a specimen with an optimum water content of 18.8% is prepared using a mold with a diameter of 50 mm and a height of 100 mm.

[0041] IV. Mechanical Property Evaluation A dynamic triaxial test is carried out on the red clay specimen with an optimum water content of 18.8% and a free iron oxide removal rate of 0% under the conditions of a confining pressure of 30 kPa, a dynamic deviator stress of 30 kPa, and a consolidation ratio of 1.5 to analyze the influence of the free iron oxide content on the dynamic resilient modulus, plastic strain, and cumulative strain rate of the red clay, as shown in the appendix. Figure 3 It is found that the attenuation degree of the dynamic resilient modulus of the red clay in this embodiment P = 0%, the dynamic performance of the red clay is in a stable state, and the corresponding cumulative plastic strain of its specimen is as shown in Figure 4 the figure, while the cumulative strain rate is as shown in Figure 5 the figure.

[0042] The embodiment of the present application also provides a quantitative evaluation system for the removal effect of free iron oxide in red clay, including a processor and a memory; The memory is used to store a computer program; The processor is used to implement any of the method steps in the quantitative evaluation method for the removal effect of free iron oxide in red clay when executing the program stored in the memory.

[0043] The above-mentioned quantitative evaluation system for the removal effect of free iron oxide in red clay can implement each embodiment of the above-mentioned quantitative evaluation method for the removal effect of free iron oxide in red clay and can achieve the same beneficial effects. Here, it will not be elaborated.

[0044] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations according to the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A quantitative evaluation method for the removal effect of free iron oxide in red clay, characterized in that, Including: Dividing the obtained target red clay into a to-be-treated sample and an untreated sample, and performing soil sample pre-treatment on the to-be-treated sample to obtain a pre-treated sample; Removing free iron oxide in the pre-treated sample through a free iron oxide removal step to obtain a removed-treated sample, and measuring the content of free iron oxide in the removed-treated sample by X-ray fluorescence spectrometry; Repeating the free iron oxide removal step for the removed-treated sample until the content of free iron oxide in the removed-treated sample measured by X-ray fluorescence spectrometry is 0, taking the removed-treated sample with a free iron oxide content of 0 as a completely treated sample, and taking the removed sample with a free iron oxide content not equal to 0 as an incompletely treated sample; Performing dynamic performance calculations on the untreated sample, the completely treated sample and the incompletely treated sample to obtain a first dynamic resilient modulus, a first cumulative plastic strain and a first cumulative strain rate corresponding to the untreated sample, obtaining a second dynamic resilient modulus, a second cumulative plastic strain and a second cumulative strain rate corresponding to the completely treated sample, and obtaining a third dynamic resilient modulus, a third cumulative plastic strain and a third cumulative strain rate corresponding to the incompletely treated sample; Determining the attenuation degree of the dynamic resilient modulus based on the first dynamic resilient modulus, the second dynamic resilient modulus and the third dynamic resilient modulus, determining the attenuation degree of the cumulative plastic strain based on the first cumulative plastic strain, the second cumulative plastic strain and the third cumulative plastic strain, and determining the attenuation degree of the cumulative strain rate based on the first cumulative strain rate, the second cumulative strain rate and the third cumulative strain rate; Quantitatively evaluating the removal effect of free iron oxide in red clay according to the attenuation degree of the dynamic resilient modulus, the attenuation degree of the cumulative plastic strain and the attenuation degree of the cumulative strain rate.

2. The quantitative evaluation method for the removal effect of free iron oxide in red clay according to claim 1, characterized in that The performing soil sample pre-treatment on the to-be-treated sample to obtain a pre-treated sample includes: Adding a sodium citrate solution and a sodium bicarbonate solution to the to-be-treated sample for stirring, and adding solid sodium dithionite to the stirred sample and then stirring again to obtain a pre-treated sample.

3. The quantitative evaluation method for the removal effect of free iron oxide in red clay according to claim 1, characterized in that, The free iron oxide removal step includes: Placing the pre-treated sample in an electrolytic cell with a graphite anode and a copper rod cathode, and applying a rated DC voltage to the electrolytic cell; Washing the electrolyzed pre-treated sample with distilled water until there is no black-brown precipitate in the supernatant to obtain a treated sample, and drying the treated sample; Screening the dried sample with a sieve, and taking the part passing through the sieve as the removed-treated sample after the free iron oxide removal step.

4. The quantitative evaluation method for the removal effect of free iron oxide in red clay according to claim 1, characterized in that, The taking the removed sample with a free iron oxide content not equal to 0 as an incompletely treated sample includes: Starting from the first free iron oxide removal step, after each free iron oxide removal step ends, dividing the obtained sample into a sample to be continuously treated and a sample not to be continuously treated; The sample to be continuously treated is used for the next free iron oxide removal step, and the sample not to be continuously treated is used as an incompletely treated sample; If the pre-treated sample undergoes N free iron oxide removal steps to obtain a removed sample with a free iron oxide content of 0, then N - 1 incompletely treated samples are obtained.

5. The quantitative evaluation method for the removal effect of free iron oxide in red clay according to claim 1, characterized in that, Performing dynamic performance calculations on the untreated samples, fully treated samples, and incompletely treated samples includes: Humidifying the untreated samples, fully treated samples, and incompletely treated samples to obtain humidified untreated samples, humidified fully treated samples, and humidified incompletely treated samples; Performing dynamic performance calculations on the humidified untreated samples to obtain the first dynamic resilient modulus, the first cumulative plastic strain, and the first cumulative strain rate corresponding to the untreated samples, and the calculations satisfy the following relational expressions: ； ； In the formula, M R1 is the first dynamic resilient modulus, σ d is the amplitude of the dynamic stress applied by the dynamic triaxial apparatus, ε r1 is the first cumulative plastic strain of the sample, is the first cumulative strain rate, ε pi and ε pi+1 are respectively the cumulative plastic strains corresponding to the number of vibration cycles N i and N i+1 ; N i and N i+1 are the number of loading i times and the number of loading i +1 times. Performing dynamic performance calculations on the humidified fully treated samples to obtain the second dynamic resilient modulus, the second cumulative plastic strain, and the second cumulative strain rate corresponding to the untreated samples, and the calculations satisfy the following relational expressions: ； ； In the formula, M R2 is the second dynamic resilience modulus, and ε r2 is the second cumulative plastic strain of the sample, is the second cumulative strain rate; Performing dynamic performance calculations on the humidified incompletely treated samples to obtain the third dynamic resilient modulus, the third cumulative plastic strain, and the third cumulative strain rate corresponding to the untreated samples, and the calculations satisfy the following relational expressions: ； ； In the formula, M R3 is the third dynamic resilient modulus, and ε r3 is the third cumulative plastic strain of the sample, is the third cumulative strain rate.

6. The quantitative evaluation method for the removal effect of free iron oxide in red clay according to claim 1, characterized in that, The calculation of the attenuation degree of the dynamic resilient modulus satisfies the following relational expressions: ； In the formula, P M is the attenuation degree of dynamic resilient modulus; M R is the dynamic resilient modulus of red clay without removing free iron oxide; M t is the removal rate of free iron oxide; t is the dynamic resilient modulus of red clay with a free iron oxide removal rate of M N is the dynamic resilient modulus of red clay with completely removed free iron oxide; The calculation of the attenuation degree adapted to the cumulative plastic strain satisfies the following relational expressions: ； Wherein, P ε is the cumulative plastic strain attenuation degree, ε t is the cumulative plastic strain of the red clay when the removal rate of free iron oxide is t , ε R is the cumulative plastic strain of the red clay without removing free iron oxide, ε N is the cumulative plastic strain of the red clay with complete removal of free iron oxide; The calculation of the attenuation degree of the cumulative strain rate satisfies the following relational expressions: ； Wherein, P v is the cumulative strain rate attenuation degree, V t is the removal rate of free iron oxide, t is the cumulative strain rate of the red clay with V R is the cumulative strain rate of the red clay without removing free iron oxide, V N is the cumulative strain rate of the red clay with complete removal of free iron oxide.

7. The quantitative evaluation method for the removal effect of free iron oxide in red clay according to claim 1, characterized in that Quantitatively evaluating the removal effect of free iron oxide in red clay according to the attenuation degree of the dynamic resilient modulus, the attenuation degree of the cumulative plastic strain, and the attenuation degree of the cumulative strain rate includes: Comparing the magnitudes of the attenuation degree of the dynamic resilient modulus, the attenuation degree of the cumulative plastic strain, and the attenuation degree of the cumulative strain rate, and taking the maximum value among the three of the attenuation degree of the dynamic resilient modulus, the attenuation degree of the cumulative plastic strain, and the attenuation degree of the cumulative strain rate; When 0% ≤ P max ≤ 25%, the structural damage degree of the red clay is low and its dynamic performance is in a stable state; When 25% ≤ P max ≤ 50%, the structural damage degree of the red clay is medium and the dynamic performance is in a critical state; When 50% ≤ P max , the structural damage degree of the red clay is high and its dynamic performance is in an unstable state; Among them, P max is the maximum value among the rebound modulus attenuation degree, the cumulative plastic strain attenuation degree, and the cumulative strain rate attenuation degree.

8. A quantitative evaluation system for the removal effect of free iron oxide in red clay, characterized in that, Including a processor and a memory; The memory is used to store a computer program; The processor is used to implement the method steps described in any one of claims 1-7 when executing the program stored on the memory.

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