A quantitative evaluation method and system for the removal 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. The method comprises the following steps: performing soil sample pretreatment on a sample to be treated to obtain a pretreated sample; removing free iron oxide from the pretreated sample through a free iron oxide removal step to obtain a removed sample, and determining the free iron oxide content in the removed sample by using an XRF test; calculating the dynamic properties of an untreated sample, a completely treated sample, and an incompletely treated sample to obtain dynamic rebound modulus attenuation, cumulative plastic strain attenuation, and cumulative strain rate attenuation; and quantitatively evaluating the removal effect of free iron oxide in red clay based on the dynamic rebound modulus attenuation, cumulative plastic strain attenuation, and cumulative strain rate attenuation. The method solves the problem that existing methods for removing free iron oxide cannot accurately determine the free iron oxide removal rate and lack quantitative evaluation of the influence of different free iron oxide removal rates on the dynamic properties of red clay.

Description

Technical Field

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

[0002] When constructing highways in red clay regions, red clay is inevitably used as a roadbed filler. However, while red clay possesses characteristics such as low expansion, low compressibility, and strong structural properties, it also suffers from high moisture content, a high plasticity index, and low strength. These shortcomings are due to the iron oxide and clay minerals in red clay. In hot, humid, and rainy regions, the fluctuating groundwater level causes the loss of free iron oxide between red clay particles, weakening the cementation and reducing the bearing capacity of the red clay roadbed. Furthermore, the cumulative deformation of the roadbed under long-term traffic dynamic loads seriously affects driving safety and comfort. However, little is currently known about the impact of microscopic cementation structure characteristics (such as free iron oxide content) on the dynamic properties of red clay under cyclic dynamic loads, leading to engineering defects such as uneven roadbed deformation, pavement cracking, and slope deformation. Therefore, it is necessary to compare the effect of free iron oxide content on the deformation properties of red clay. Currently, traditional methods for removing free iron oxide (immersion and infiltration) suffer from slow processing times, complex procedures, and low removal rates. Furthermore, existing methods rarely measure the amount of free iron oxide removed, making it impossible to assess the effectiveness of these methods. Consequently, existing methods for removing free iron oxide are unable to accurately determine free iron oxide removal rates, and lack a quantitative assessment of the impact of different free iron oxide removal rates on the dynamic properties 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, so as to solve the problem that the existing method for removing free iron oxide cannot accurately measure the free iron oxide removal rate and lacks a quantitative evaluation of the impact of different free iron oxide removal rates on the dynamic performance of red clay.

[0004] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0005] In a first aspect, the present invention provides a method for quantitatively evaluating the removal effect of free iron oxide in red clay, comprising:

[0006] The obtained target red clay is divided into a to-be-treated sample and an untreated sample, and the to-be-treated sample is subjected to soil sample pretreatment to obtain a pretreated sample;

[0007] removing free iron oxide from the pretreated sample by a free iron oxide removal step to obtain a removed sample, and determining the free iron oxide content in the removed sample by an X-ray fluorescence spectrometry test;

[0008] Repeating the free iron oxide removal step for the removed sample until the free iron oxide content in the removed sample measured by X-ray fluorescence spectrometry is 0, the removed sample with a free iron oxide content of 0 is regarded as a completely treated sample, and the removed sample with a free iron oxide content not 0 is regarded as an incompletely treated sample;

[0009] Performing dynamic performance calculations on the untreated sample, the completely treated sample, and the incompletely treated sample to obtain a first dynamic elastic modulus, a first cumulative plastic strain, and a first cumulative strain rate corresponding to the untreated sample, a second dynamic elastic modulus, a second cumulative plastic strain, and a second cumulative strain rate corresponding to the completely treated sample, and a third dynamic elastic modulus, a third cumulative plastic strain, and a third cumulative strain rate corresponding to the incompletely treated sample;

[0010] determining a dynamic modulus of elasticity attenuation based on the first dynamic modulus of elasticity, the second dynamic modulus of elasticity, and the third dynamic modulus of elasticity, determining a cumulative plastic strain attenuation based on the first cumulative plastic strain, the second cumulative plastic strain, and the third cumulative plastic strain, and determining a cumulative strain rate attenuation based on the first cumulative strain rate, the second cumulative strain rate, and the third cumulative strain rate;

[0011] The removal effect of free iron oxide in red clay is quantitatively evaluated according to the dynamic rebound modulus attenuation, the cumulative plastic strain attenuation and the cumulative strain rate attenuation.

[0012] Optionally, the step of performing soil sample pretreatment on the sample to be processed to obtain a pretreated sample includes:

[0013] Sodium citrate solution and sodium bicarbonate solution are added to the sample to be treated and stirred, and solid sodium dithionite is added to the stirred sample and stirred again to obtain a pretreated sample.

[0014] Optionally, the free iron oxide removal step comprises:

[0015] Placing the pretreated sample in an electrolytic cell with a graphite anode and a copper rod cathode, and applying a rated DC voltage to the electrolytic cell;

[0016] The pre-treated sample after electrolysis was washed with distilled water until the supernatant was free of dark brown precipitates to obtain the treated sample, and the treated sample was dried;

[0017] The dried sample was screened using a sieve, and the portion passing through the sieve was used as the removed sample after the free iron oxide removal step.

[0018] Optionally, treating the removed sample with a free iron oxide content not equal to 0 as an incompletely processed sample includes:

[0019] Starting from the first free iron oxide removal step, after each free iron oxide removal step, the obtained samples are divided into samples to be processed and samples not to be processed;

[0020] 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;

[0021] 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.

[0022] Optionally, the performing of dynamic performance calculation on the unprocessed sample, the completely processed sample, and the incompletely processed sample includes:

[0023] 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;

[0024] 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:

[0025] ;

[0026] ;

[0027] 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;

[0028] 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:

[0029] ;

[0030] ;

[0031] 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;

[0032] The dynamic performance of the incompletely treated sample after humidification was calculated to obtain the third dynamic rebound modulus, the third cumulative plastic strain and the third cumulative strain rate corresponding to the untreated sample. The calculation satisfies the following relationship:

[0033] ;

[0034] ;

[0035] Where, M R3 is the third dynamic rebound modulus, ε r3 is the third accumulated plastic strain of the sample, is the third cumulative strain rate.

[0036] Optionally, the calculation of the dynamic rebound modulus attenuation satisfies the following relationship:

[0037] ;

[0038] Where, P M is the attenuation of dynamic elastic modulus, M R is the dynamic rebound modulus of red clay without removing free iron oxide, M t The removal rate of free iron oxide is t The dynamic rebound modulus of red clay, M N The dynamic rebound modulus of red clay with complete removal rate of free iron oxide;

[0039] The calculation of the cumulative plastic strain attenuation satisfies the following relationship:

[0040] ;

[0041] Where, P ε is the cumulative plastic strain decay, ε t When the free iron oxide removal rate is t The accumulated plastic strain of red clay at εR is the accumulated plastic strain of red clay without removing free iron oxide, ε N The accumulated plastic strain of red clay with complete removal rate of free iron oxide;

[0042] The calculation of the cumulative strain rate attenuation satisfies the following relationship:

[0043] ;

[0044] Where, P v is the cumulative strain rate decay, V t The removal rate of free iron oxide is t The cumulative strain rate of red clay, V R is the cumulative strain rate of red clay without removing free iron oxide, V N Cumulative strain rate of red clay for complete removal of free iron oxide.

[0045] Optionally, the quantitative evaluation of the removal effect of free iron oxide in red clay according to the dynamic rebound modulus attenuation, the cumulative plastic strain attenuation, and the cumulative strain rate attenuation includes:

[0046] Compare the dynamic elastic modulus attenuation, cumulative plastic strain attenuation, and cumulative strain rate attenuation, and take the maximum value among the three;

[0047] When 0%≤ P max When ≤25%, the red clay structure is at low damage level and the dynamic performance is stable;

[0048] When 25%≤ P max When ≤50%, the red clay structure damage is moderate and the dynamic performance is critical;

[0049] When 50%≤ P max When , the red clay structure is highly damaged and the dynamic performance is unstable;

[0050] in, P max It is the maximum value among the attenuation of rebound modulus, cumulative plastic strain and cumulative strain rate.

[0051] In a second aspect, an embodiment of the present application provides a system for quantitatively evaluating the removal effect of free iron oxide in red clay, comprising a processor and a memory;

[0052] Memory for storing computer programs;

[0053] The processor is configured to implement any one of the method steps described in the first aspect when executing a program stored in the memory.

[0054] Beneficial effects:

[0055] The present invention provides a quantitative evaluation method for the removal effect of free iron oxide in red clay. The method utilizes sodium dithionite, sodium citrate, and sodium bicarbonate as treatment agents, can efficiently destroy the colloidal structure of free iron oxide, achieve rapid removal of free iron oxide through electric field-driven redox, and quantitatively measure the free iron oxide removal rates of different red clay samples through X-ray fluorescence spectroscopy, thereby solving the problem that existing methods cannot accurately measure the free iron oxide removal rate. The method is simple to operate, has a short test cycle, and is suitable for large-scale treatment. The dynamic performance of samples with different free iron oxide contents is evaluated through dynamic triaxial testing, and the influence of free iron oxide on the mechanical properties of red clay can be accurately analyzed. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a flow chart of a method for quantitatively evaluating the removal effect of free iron oxide in red clay according to a preferred embodiment of the present invention;

[0057] Figure 2 Schematic diagram of X-ray fluorescence spectroscopy test results of a preferred embodiment of the present invention;

[0058] Figure 3 A schematic diagram of the dynamic elastic modulus results provided for a preferred embodiment of the present invention;

[0059] Figure 4 A schematic diagram of cumulative deformation results provided by a preferred embodiment of the present invention;

[0060] Figure 5 A schematic diagram of the cumulative strain rate results provided by a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0061] The following is a clear and complete description of the technical solutions of the present invention. It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0062] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "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, words such as "one" or "a" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship also changes accordingly.

[0063] Example 1

[0064] See Figure 1 The present invention provides a method for quantitatively evaluating the removal effect of free iron oxide in red clay, comprising:

[0065] The obtained target red clay is divided into a to-be-treated sample and an untreated sample, and the to-be-treated sample is subjected to soil sample pretreatment to obtain a pretreated sample;

[0066] The free iron oxide in the pre-treated sample is removed by a free iron oxide removal step to obtain a removed sample, and the free iron oxide content in the removed sample is determined by an X-ray fluorescence spectrometry (XRF) test;

[0067] Repeating the free iron oxide removal step for the removed sample until the free iron oxide content in the removed sample measured by X-ray fluorescence spectrometry is 0, the removed sample with a free iron oxide content of 0 is regarded as a completely treated sample, and the removed sample with a free iron oxide content not 0 is regarded as an incompletely treated sample;

[0068] The dynamic properties of the untreated sample, the completely treated sample and the incompletely treated sample are calculated to obtain the first dynamic elastic modulus, the first cumulative plastic strain and the first cumulative strain rate corresponding to the untreated sample, the second dynamic elastic modulus, the second cumulative plastic strain and the second cumulative strain rate corresponding to the completely treated sample, and the third dynamic elastic modulus, the third cumulative plastic strain and the third cumulative strain rate corresponding to the incompletely treated sample;

[0069] determining a dynamic modulus attenuation degree based on the first dynamic modulus of elasticity, the second dynamic modulus of elasticity, and the third dynamic modulus of elasticity, determining a cumulative plastic strain attenuation degree based on the first cumulative plastic strain, the second cumulative plastic strain, and the third cumulative plastic strain, and determining a cumulative strain rate attenuation degree based on the first cumulative strain rate, the second cumulative strain rate, and the third cumulative strain rate;

[0070] The removal effect of free iron oxide in red clay was quantitatively evaluated based on the dynamic rebound modulus attenuation, cumulative plastic strain attenuation and cumulative strain rate attenuation.

[0071] The following describes the different steps for removing free iron oxide:

[0072] 1. Soil sample pretreatment

[0073] 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.

[0074] 2. Chemical Dissolution Method

[0075] Add 50 g of solid sodium dithionite and continue stirring for 15 minutes to allow the mixed solution to react fully.

[0076] 3. Electric Field Driven Redox

[0077] The mixed solution is placed in an electrolytic cell with graphite as the anode and copper rod as the cathode, and a rated DC voltage is applied to the electrolytic cell. An oxidation reaction occurs in the anode area, destroying the structure of iron oxide; a reduction reaction occurs in the cathode area, converting Fe 3+ Reduced to Fe that is more easily reactive with chemical reagents 2+ The electrochemical treatment lasted for 15 minutes.

[0078] 4. Washing and Standing

[0079] The soil samples were washed with distilled water until no dark brown precipitate appeared in the supernatant, and then allowed to stand for 12 hours.

[0080] 5. Testing and Analysis

[0081] After drying the red clay sample in a 50°C oven, the soil sample was passed through a 0.074 mm sieve and the free iron oxide content removed was determined by XRF testing. The red clay oxide content with a free iron oxide removal rate of 21% was obtained. Figure 2 shown.

[0082] 6. Sample preparation

[0083] The red clay sample was passed through a 2 mm sieve and atomized and humidified with a free iron oxide removal rate of 21% under the condition of a spray volume of 200 ml / h of an atomizing humidifier until the moisture content of the soil sample reached the optimal moisture content of 18.8%. Then, a mold with a diameter of 50 mm and a height of 100 mm was used to prepare a sample with an optimal moisture content of 18.8%.

[0084] 7. Mechanical properties evaluation

[0085] Dynamic triaxial tests were carried out on red clay samples with an optimum moisture content of 18.8% and a free iron oxide removal rate of 21% under conditions of 30 kPa confining pressure, 30 kPa dynamic deviatoric stress, and a consolidation ratio of 1.5. The effects of free iron oxide content on the dynamic rebound modulus, plastic strain, and cumulative strain rate of red clay were analyzed. Figure 3 It is found that the red clay dynamic rebound modulus of this embodiment has the largest attenuation, which is P =24%, the red clay structure is low in damage and its dynamic performance is stable. The corresponding accumulated plastic strain of the sample is as follows: Figure 4 As shown, the cumulative strain rate is as Figure 5 shown.

[0086] Example 2

[0087] 1. Soil sample pretreatment

[0088] 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.

[0089] 2. Chemical Dissolution Method

[0090] Add 50 g of solid sodium dithionite and continue stirring for 15 minutes to allow the mixed solution to react fully.

[0091] 3. Electric Field Driven Redox

[0092] The mixed solution is placed in an electrolytic cell with graphite as the anode and copper rod as the cathode, and a rated DC voltage is applied to the electrolytic cell. An oxidation reaction occurs in the anode area, destroying the structure of iron oxide; a reduction reaction occurs in the cathode area, converting Fe 3+ Reduced to Fe that is more easily reactive with chemical reagents 2+ The electrochemical treatment lasted for 15 minutes.

[0093] 4. Washing and Standing

[0094] The soil samples were washed with distilled water until no dark brown precipitate appeared in the supernatant, and then allowed to stand for 24 hours.

[0095] 5. Testing and Analysis

[0096] After drying the red clay sample in a 50°C oven, the soil sample was passed through a 0.074 mm sieve and the free iron oxide content removed was determined by XRF testing. The red clay oxide content with a free iron oxide removal rate of 48% was obtained. Figure 2 shown.

[0097] 6. Sample preparation

[0098] The red clay sample was passed through a 2 mm sieve and atomized and humidified with a free iron oxide removal rate of 48% under the condition of a spray volume of 200 ml / h of an atomizing humidifier until the moisture content of the soil sample reached the optimal moisture content of 18.8%. Then, a mold with a diameter of 50 mm and a height of 100 mm was used to prepare a sample with an optimal moisture content of 18.8%.

[0099] 7. Mechanical properties evaluation

[0100] Dynamic triaxial tests were carried out on red clay samples with an optimum moisture content of 18.8% and a free iron oxide removal rate of 48% under conditions of 30 kPa confining pressure, 30 kPa dynamic deviatoric stress, and a consolidation ratio of 1.5. The effects of free iron oxide content on the dynamic rebound modulus, plastic strain, and cumulative strain rate of red clay were analyzed. Figure 3 It is found that the red clay dynamic rebound modulus of this embodiment has the largest attenuation, which is P =55%, the red clay structure damage is moderate, the dynamic performance is critical, and the corresponding cumulative plastic strain of the sample is as follows: Figure 4 As shown, the cumulative strain rate is as Figure 5 shown.

[0101] Example 3

[0102] 1. Soil sample pretreatment

[0103] 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.

[0104] 2. Chemical Dissolution Method

[0105] Add 50 g of solid sodium dithionite and continue stirring for 15 minutes to allow the mixed solution to react fully.

[0106] 3. Electric Field Driven Redox

[0107] The mixed solution is placed in an electrolytic cell with graphite as the anode and copper rod as the cathode, and a rated DC voltage is applied to the electrolytic cell. An oxidation reaction occurs in the anode area, destroying the structure of iron oxide; a reduction reaction occurs in the cathode area, converting Fe 3+ Reduced to Fe that is more easily reactive with chemical reagents 2+ The electrochemical treatment lasted for 15 minutes.

[0108] 4. Washing and Standing

[0109] The soil samples were washed with distilled water until no dark brown precipitate appeared in the supernatant, and then allowed to stand for 48 hours.

[0110] 5. Testing and Analysis

[0111] After drying the red clay sample in a 50°C oven, the soil sample was passed through a 0.074 mm sieve and the free iron oxide content removed was determined by XRF testing. The red clay oxide content with a free iron oxide removal rate of 79% was obtained. Figure 2 shown.

[0112] 6. Sample preparation

[0113] The red clay sample was passed through a 2 mm sieve and atomized and humidified with a free iron oxide removal rate of 79% under the condition of a spray volume of 200 ml / h in an atomizing humidifier until the moisture content of the soil sample reached the optimal moisture content of 18.8%. Then, a mold with a diameter of 50 mm and a height of 100 mm was used to prepare a sample with an optimal moisture content of 18.8%.

[0114] 7. Mechanical properties evaluation

[0115] Dynamic triaxial tests were carried out on red clay samples with an optimum moisture content of 18.8% and a free iron oxide removal rate of 79% under conditions of 30 kPa confining pressure, 30 kPa dynamic deviatoric stress, and a consolidation ratio of 1.5. The effects of free iron oxide content on the dynamic rebound modulus, plastic strain, and cumulative strain rate of red clay were analyzed. Figure 3 It is found that the red clay dynamic rebound modulus of this embodiment has the largest attenuation, which is P =82%, the red clay structure is highly damaged and its dynamic performance is unstable. The corresponding accumulated plastic strain of the sample is as follows: Figure 4 As shown, the cumulative strain rate is as Figure 5 shown.

[0116] Example 4

[0117] 1. Soil sample

[0118] Take 2 kg of air-dried red clay.

[0119] 2. Testing and Analysis

[0120] The soil sample was passed through a 0.074 mm sieve and the free iron oxide content was determined by XRF test. The red clay oxide content with a free iron oxide removal rate of 0% was obtained. Figure 2 shown.

[0121] 3. Sample preparation

[0122] The red clay sample was passed through a 2 mm sieve and atomized and humidified with a free iron oxide removal rate of 0% under the condition of a spray volume of 200 ml / h of an atomizing humidifier until the moisture content of the soil sample reached the optimal moisture content of 18.8%. Then, a mold with a diameter of 50 mm and a height of 100 mm was used to prepare a sample with an optimal moisture content of 18.8%.

[0123] 4. Mechanical properties evaluation

[0124] Dynamic triaxial tests were carried out on red clay samples with an optimum moisture content of 18.8% and a free iron oxide removal rate of 0% under conditions of 30 kPa confining pressure, 30 kPa dynamic deviatoric stress, and a consolidation ratio of 1.5. The effects of free iron oxide content on the dynamic rebound modulus, plastic strain, and cumulative strain rate of red clay were analyzed. Figure 3 It is found that the dynamic rebound modulus of the red clay in this embodiment is attenuated by P = 0%, the dynamic performance of red clay is in a stable state, and the corresponding cumulative plastic strain of the sample is as follows: Figure 4 As shown, the cumulative strain rate is as Figure 5 shown.

[0125] The embodiment of the present application also provides a system for quantitatively evaluating the removal effect of free iron oxide in red clay, comprising a processor and a memory;

[0126] Memory for storing computer programs;

[0127] The processor is configured to implement any one of the method steps described in the method for quantitatively evaluating the removal effect of free iron oxide in red clay when executing the program stored in the memory.

[0128] The above-mentioned system for quantitatively evaluating the removal effect of free iron oxide in red clay can implement various embodiments of the above-mentioned method for quantitatively evaluating the removal effect of free iron oxide in red clay and achieve the same beneficial effects, which will not be described in detail here.

[0129] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A quantitative evaluation method for the removal of free iron oxide in red clay, characterized in that: include: The obtained target red clay is divided into a to-be-treated sample and an untreated sample, and the to-be-treated sample is subjected to soil sample pretreatment to obtain a pretreated sample; removing free iron oxide from the pretreated sample by a free iron oxide removal step to obtain a removed sample, and determining the free iron oxide content in the removed sample by an X-ray fluorescence spectrometry test; Repeating the free iron oxide removal step for the removed sample until the free iron oxide content in the removed sample measured by X-ray fluorescence spectrometry is 0, the removed sample with a free iron oxide content of 0 is regarded as a completely treated sample, and the removed sample with a free iron oxide content not 0 is regarded 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 elastic modulus, a first cumulative plastic strain, and a first cumulative strain rate corresponding to the untreated sample, a second dynamic elastic modulus, a second cumulative plastic strain, and a second cumulative strain rate corresponding to the completely treated sample, and a third dynamic elastic modulus, a third cumulative plastic strain, and a third cumulative strain rate corresponding to the incompletely treated sample; determining a dynamic modulus of elasticity attenuation based on the first dynamic modulus of elasticity, the second dynamic modulus of elasticity, and the third dynamic modulus of elasticity, determining a cumulative plastic strain attenuation based on the first cumulative plastic strain, the second cumulative plastic strain, and the third cumulative plastic strain, and determining a cumulative strain rate attenuation based on the first cumulative strain rate, the second cumulative strain rate, and the third cumulative strain rate; The removal effect of free iron oxide in red clay is quantitatively evaluated according to the dynamic rebound modulus attenuation, the cumulative plastic strain attenuation and the cumulative strain rate attenuation; The step of performing soil sample pretreatment on the sample to be processed to obtain a pretreated sample comprises: adding sodium citrate solution and sodium bicarbonate solution to the sample to be treated and stirring, adding solid sodium dithionite to the stirred sample and stirring again to obtain a pretreated sample; The free iron oxide removal step comprises: Placing the pretreated sample in an electrolytic cell with a graphite anode and a copper rod cathode, and applying a rated DC voltage to the electrolytic cell; The pre-treated sample after electrolysis was washed with distilled water until the supernatant was free of dark brown precipitates to obtain the treated sample, and the treated sample was dried; The dried sample was screened using a sieve, and the portion passing through the sieve was used as the removed sample after the free iron oxide removal step.

2. The method for quantitatively evaluating the removal effect of free iron oxide in red clay according to claim 1, wherein: The removing sample with a free iron oxide content not being 0 as an incompletely processed sample comprises: Starting from the first free iron oxide removal step, after each free iron oxide removal step, the obtained samples are divided into samples to be processed and samples not to be processed; 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.

3. The method for quantitatively evaluating the removal effect of free iron oxide in red clay according to claim 1, wherein: The calculation of the dynamic performance of 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 was calculated to obtain the first dynamic rebound modulus, the first cumulative plastic strain, and the first cumulative strain rate corresponding to the untreated sample. The calculation satisfied 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, second cumulative plastic strain and second cumulative strain rate corresponding to the untreated sample, and the calculation satisfied 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 was calculated to obtain the third dynamic rebound modulus, the third cumulative plastic strain and the third cumulative strain rate corresponding to the untreated sample, and the calculation satisfied the following relationship: ； ； Where, M R3 is the third dynamic rebound modulus, ε r3 is the third accumulated plastic strain of the sample, is the third cumulative strain rate.

4. The method for quantitatively evaluating the removal effect of free iron oxide in red clay according to claim 1, wherein: The calculation of the dynamic rebound modulus attenuation satisfies the following relationship: ； Where, P M is the attenuation of dynamic elastic modulus, M R is the dynamic rebound modulus of red clay without removing free iron oxide, M t The removal rate of free iron oxide is t The dynamic rebound modulus of red clay, M N The dynamic rebound modulus of red clay with complete removal rate of free iron oxide; The calculation of the cumulative plastic strain attenuation satisfies the following relationship: ； Where, P ε is the cumulative plastic strain decay, ε t When the free iron oxide removal rate is t The accumulated plastic strain of red clay at ε R is the accumulated plastic strain of red clay without removing free iron oxide, ε N The accumulated plastic strain of red clay with complete removal rate of free iron oxide; The calculation of the cumulative strain rate attenuation satisfies the following relationship: ； Where, P v is the cumulative strain rate decay, V t The removal rate of free iron oxide is t The cumulative strain rate of red clay, V R is the cumulative strain rate of red clay without removing free iron oxide, V N Cumulative strain rate of red clay for complete removal of free iron oxide.

5. The method for quantitatively evaluating the removal effect of free iron oxide in red clay according to claim 1, wherein: The quantitative evaluation of the removal effect of free iron oxide in red clay according to the dynamic rebound modulus attenuation, the cumulative plastic strain attenuation and the cumulative strain rate attenuation includes: Compare the dynamic elastic modulus attenuation, cumulative plastic strain attenuation, and cumulative strain rate attenuation, and take the maximum value among the three; When 0%≤ P max When ≤25%, the red clay structure is at low damage level and the dynamic performance is stable; When 25%≤ P max When ≤50%, the red clay structure damage is moderate and the dynamic performance is critical; When 50%≤ P max When , the red clay structure is highly damaged and the dynamic performance is unstable; in, P max It is the maximum value among the attenuation of rebound modulus, cumulative plastic strain and cumulative strain rate.

6. A quantitative evaluation system for the removal of free iron oxide in red clay, characterized in that: Including processor and memory; Memory for storing computer programs; A processor, configured to implement the method steps described in any one of claims 1 to 5 when executing a program stored in a memory.

Images