A method for correcting the formula of water addition amount for specimens in the compaction test of roadbed alkali residue lime soil

Abstract

The present invention discloses a method for correcting the water addition formula of specimens in the compaction test of roadbed alkali residue lime soil. First, determine the ratio of alkali residue lime soil, use part of the alkali residue to replace part of the soil, and keep the mass of lime unchanged; calculate the water addition amount required to reach the target water content; select multiple groups of materials with different alkali residue dosages, test the natural water contents of the alkali residue and soil raw materials, and calculate the water addition amounts required for multiple groups of materials to reach the designed target water content; test the actual water contents of the test groups; analyze the errors between the calculated actual water contents of each group of specimens and the designed target water content; determine the correction coefficient of the water content formula; verify the accuracy of the correction coefficient. The present invention improves the accuracy of the water addition amount based on the correction coefficient, making the error between the actual water content and the target function smaller, thereby improving the accuracy of the test, and providing reference for the optimized design of the alkali residue lime soil ratio and the control of the moisture content in on-site construction.

Description

Technical Field

[0001] The present invention relates to a compaction test of alkali residue lime soil in the field of inorganic binder building materials for highway engineering, and particularly to a method for correcting the formula of the water addition amount of the specimen in the compaction test of road-use alkali residue lime soil. Background Art

[0002] In recent years, in order to treat alkali residue solid waste, by utilizing the gelling property of alkali residue, excellent alkali residue lime soil is prepared by replacing part of the soil in lime with alkali residue. During the mix proportion design and on-site construction process of alkali residue lime soil materials, the moisture content is a key factor. For example, during the design of the optimal mix proportion of alkali residue lime soil for the road surface base course, the general process is to optimally select the best mix proportion according to the strength indexes of different mix proportion target groups. And for each group of alkali residue lime soil materials, the strength needs to be tested under the optimal moisture content state. Therefore, for each group, 4 - 6 groups of different target moisture content test groups are first designed, and the optimal moisture content of each group is obtained through the dry density index of each group. When testing the dry density under the state of each group's target moisture content, a compaction test needs to be carried out. For each group, in order to reach the target moisture content, the corresponding amount of water needs to be added to the alkali residue lime soil mixture. The water addition amount formula given in the compaction test in the "Test Regulations for Inorganic Binder Stabilized Materials in Highway Engineering JTG E51 - 2009" mainly aims at traditional inorganic binder stabilized materials such as lime. As a new type of solid waste building material, the reaction mechanism and strength production mechanism of alkali residue lime soil are relatively special. During the material forming process, its reaction with water is different from that of ordinary lime. Therefore, the original water addition amount formula is not suitable for alkali residue lime soil and needs to be corrected.

[0003] During the research on the mix proportion design of alkali residue lime soil, it is found that after calculating the water amount to be added to the specimen according to the water addition amount formula given in the specification during the compaction test and adding it, there is a large difference between the actual water content of the measured alkali residue lime soil mixture and the designed target moisture content. Through the analysis of the basic physical and chemical properties of alkali residue, on the one hand, with the incorporation of alkali residue, an internal chemical reaction may occur between the alkali residue and the water in the specimen, thereby consuming a part of the water and making the water addition amount requirement increase; on the other hand, the addition of alkali residue will react with lime, and even among alkali residue, lime, and soil, consuming a part of quicklime, thereby reducing the reaction between quicklime and water and reducing the water addition amount requirement. In short, with the incorporation of alkali residue into lime, various physical and chemical reactions occur among alkali residue, lime, and soil, and the internal mechanism is complex and changeable. The original water addition amount formula cannot better meet the accuracy of the water addition requirement of alkali residue lime soil materials, and needs to be corrected on the basis of the original formula to ensure the accuracy of the water addition amount calculation, so as to ensure the correctness of the mix proportion design of alkali residue lime soil and provide a guarantee for controlling the optimal moisture content during the construction process. Summary of the Invention

[0004] Objective of the invention: Aiming at the deficiencies existing in the prior art, the present invention proposes a method for correcting the water addition formula of the compaction test specimen of roadbed alkali residue lime soil. The correction coefficient is obtained through experiments, and the accuracy of the water addition is improved based on the correction coefficient, so that the error between the actual water content and the target function is smaller, thereby improving the accuracy of the test.

[0005] Technical solution: The method for correcting the water addition formula of the compaction test specimen of roadbed alkali residue lime soil of the present invention includes the following steps:

[0006] (1) Determine the ratio of alkali residue lime soil, use part of the alkali residue to replace part of the soil, and keep the mass of lime unchanged;

[0007] (2) Calculate the water addition amount to reach the target water content; select multiple groups of materials with different alkali residue contents, test the natural water contents of the alkali residue and the soil, and calculate the water addition amounts of multiple groups of materials to reach the target water content;

[0008] (3) Test the actual water content of the test group;

[0009] (4) Analyze the error between the calculated actual water content of each group of specimens and the designed target water content;

[0010] (5) Design the correction coefficient of the water addition formula and calibrate the parameters;

[0011] (6) Verify the accuracy of the correction coefficient of the water addition formula.

[0012] The water addition formula for the specimen in step (2) is:

[0013]

[0014] m w —The water addition amount (g) in the alkali residue lime soil;

[0015] m n —The mass (g) of the soil in the alkali residue lime soil, and the natural water content of the soil is w n (%);

[0016] m c —The mass (g) of the lime in the alkali residue lime soil, and the natural water content of the lime is w c (%);

[0017] m k —The mass (g) of the alkali residue in the alkali residue lime soil, and the natural water content of the alkali residue is w k (%);

[0018] w—The target water content (%) of the alkali residue lime soil required to be reached.

[0019] The process of step (3) is as follows:

[0020] (3.1) Dry and crush the lime and alkali residue, and screen them using a standard sieve;

[0021] (3.2) Prepare the alkali residue lime soil mixture with multiple groups of materials according to the preset target water content. Spray the calculated amount of water to be added onto the mixture, and put the mixture added with water into an airtight bag and immerse it in water for wetting and curing;

[0022] (3.3) Take out the wetted mixture and remix it, and conduct standard light or heavy compaction tests according to the particle size of the soil particles;

[0023] (3.4) Take samples using a core cutter, weigh the mass of the alkali residue lime soil inside the sample, and calculate the dry density of the sample;

[0024] (3.5) Scrape the test specimen from the core cutter, dry the test specimen, and measure the average moisture content of the test specimen; Repeat the above steps to measure the actual water content of each group of test specimens.

[0025] In step (5), add a correction coefficient η to the basis of formula (2), and the expression of η is as follows:

[0026] η = aX + bY + c (Equation 3)

[0027] η - correction coefficient, the value is the mass of added water obtained by correcting the theoretical formula divided by the original theoretical mass of added water (g);

[0028] a - calibration parameter affected by alkali residue;

[0029] b - calibration parameter affected by the predetermined water content;

[0030] c - formula calibration constant;

[0031] X - alkali residue content (%);

[0032] Y - predetermined water content (%).

[0033] Use η to correct the formula, and the new corrected formula is:

[0034] m = η·m w (Equation 4)

[0035] m - the mass of added water after correction (g);

[0036] η - correction coefficient, the value is the mass of added water obtained by correcting the theoretical formula divided by the mass of added water from the derived formula (g);

[0037] m w - the amount of water to be added to the mixture (g).

[0038] In step (2), the natural water contents of the alkali residue and soil are measured using the drying method.

[0039] The lime in step (3.1) is anhydrous lime.

[0040] In step (3.1), the lime and alkali residue are dried, crushed and screened with a 4.75 mm standard sieve.

[0041] In step (3.4), a core cutter is used to take samples. If there is any deficiency on the surface of the sample, the test sample is taken for repair.

[0042] In step (3.5), the test sample is scraped from the core cutter and placed in a box respectively, and the mass of the box and the box plus the test sample is weighed. The test sample is dried and the average moisture content of the test sample is measured.

[0043] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0044] By correcting the water addition amount of the test sample, the present invention makes the moisture content of the alkali residue lime soil configuration more accurate and closer to the optimum moisture content, thus providing a reference basis for the proportion design of the alkali residue lime soil and the addition of the in-situ moisture content. Description of the Drawings

[0045] Figure 1 is the flow chart for correcting the formula of the water addition amount of the test sample for the compaction test of road-use alkali residue lime soil of the present invention;

[0046] Figure 2 is the drawing of the alkali residue sample;

[0047] Figure 3 is the drawing of the lime sample;

[0048] Figure 4 is the drawing of the soil sample;

[0049] Figure 5 is the drawing of the compaction test;

[0050] Figure 6 is the drawing of the drying experiment. Detailed Embodiments

[0051] The method for correcting the formula of the water addition amount of the test sample for the compaction test of road-use alkali residue lime soil of the present invention includes the following steps:

[0052] Step (1): Determine the proportion of the alkali residue lime soil.

[0053] The main raw materials used in the alkali residue lime soil involved in the test are alkali residue, lime and soil. Part of the alkali residue is used to replace part of the soil, while the quality of the lime remains unchanged. Among them, group A0 is the control group test without alkali residue (12% lime). According to the proportion of alkali residue replacing soil, a total of five groups of tests, A1 - A5, are adopted. Referring to the original optimal moisture content level y% of the A0 control group, each of the A1 - A5 groups sets 5 target water contents, which are y - 2%, y - 1%, y%, y + 1%, and y + 2% respectively.

[0054] Step (2): Calculate the water addition amount required for the test group to reach the target water content.

[0055] Select five groups of tests, A1 - A5, with different alkali residue dosages. Each group sets 5 target water contents, totaling 25 groups of materials. The natural water contents of the alkali residue and soil are measured by the drying method. According to the formula (T 0804 - 1) in the "Test Regulations for Inorganic Binding Material Stabilized Materials in Highway Engineering JTG E51 - 2009", the water addition amount required for the 25 groups of materials to reach the target water content is calculated. The original formula in the standard is shown in formula (1).

[0056]

[0057] m w —The water addition amount in lime - stabilized soil;

[0058] m n —The mass of soil in lime - stabilized soil (g), and the natural water content of the soil is w n (%);

[0059] m c —The mass of lime in lime - stabilized soil (g), and the natural water content of the lime is w c (%);

[0060] w—The target water content of lime - stabilized soil to be achieved (%).

[0061] Considering the addition of alkali residue, the new water addition amount formula is shown in (formula 2):

[0062]

[0063] m w —The water addition amount in alkali residue lime soil (g);

[0064] m n —The mass of soil in alkali residue lime soil (g), and the natural water content of the soil is w n (%);

[0065] m c —The mass of lime in alkali residue lime soil (g), and the natural water content of the lime is w c (%);

[0066] m k — The mass (g) of alkali residue in the alkali residue lime soil, and the natural water content of the alkali residue is w k (%);

[0067] w — The target water content (%) of the alkali residue lime soil to be achieved.

[0068] Step (3): Test the actual water content of the test group, and the specific steps are as follows:

[0069] (3.1) The lime is anhydrous lime. After the lime and alkali residue raw materials are naturally dried, they are crushed and screened through a 4.75 mm standard sieve;

[0070] (3.2) 25 groups of materials are used to prepare alkali residue lime soil mixtures according to the preset target water content. The calculated amount of water to be added, tap water, is sprayed onto the mixture with a spray bottle. The mixture with water added is put into an impermeable sealed bag, tied, and immersed in water for wetting and soaking;

[0071] (3.3) Take out the mixture soaked for 24 hours and remix it, and conduct standard light or heavy compaction tests according to the particle size of the soil particles;

[0072] (3.4) Use a core cutter to take samples, observe whether there is any missing on the surface, and if so, take samples to repair. Then wipe the core cutter clean, weigh the mass of the alkali residue lime soil inside the sample, and calculate the dry density of the sample;

[0073] (3.5) Scrape a certain mass of samples from the core cutter and place them in several aluminum boxes respectively, and weigh the mass of the aluminum box and the aluminum box plus the sample. Dry the sample to measure its average moisture content. Repeat the above steps to measure the actual water content of each group of 25 samples.

[0074] Step (4): Calculate the actual water content of each group of specimens and analyze the error from the designed target water content;

[0075] After conducting indoor light compaction tests, measure the actual water content of each specimen, conduct error analysis with the target water content set for each group, and calculate the error between the actual water content and the target water content of 25 groups of samples.

[0076] Step (5): Design the correction coefficient of the water addition formula and calibrate the parameters

[0077] In order to obtain a more accurate water addition formula applicable to the designed target water content of alkali residue lime soil, it is proposed that on the basis of error analysis, a correction coefficient η is added to the original water addition formula (2). The correction coefficient η is a coefficient related to the alkali residue content and the target water content, so that the generated new formula takes into account the influence of the alkali residue content and the change of the preset water content on the water addition amount. The expression of η is shown in formula (3):

[0078] η = aX + bY + c (Equation 3)

[0079] Where: X represents the dosage of alkali residue, and Y represents the target water content. a - Calibration parameter affected by alkali residue, obtained through error analysis calibration; b - Calibration parameter affected by target water content, obtained through error analysis calibration; c - Formula calibration constant;

[0080] Then the new water addition formula (4).

[0081] m = η·m w (Equation 4)

[0082] Step (6): Verify the accuracy of the formula

[0083] To verify the accuracy of the new water addition formula proposed by the present invention, lime soil with alkali residue content and target water content is randomly selected. The water addition of the mixture is calculated according to the new formula, and then samples are taken by ring knife through compaction test. The actual water content is calculated by drying method, and the error between the actual water content and the designed target water content is calculated again to compare and analyze the accuracy of the new formula.

[0084] Specific implementation case:

[0085] Step (1): Determine the mix ratio of lime soil with alkali residue.

[0086] (1.1) Raw material treatment and basic property testing

[0087] The physical and chemical properties of the as - received wet alkali residue, lime and soil were analyzed, and all met the requirements of the regulations and could be used for experiments. After the materials were transported to the laboratory, they were screened with a standard sieve, and the particles passing through the 4.75 - mm square hole sieve were retained, and then air - dried for 4 - 5 days under natural conditions to reach the natural air - dried water content.

[0088] (1.2) Determine the mix ratio

[0089] The main materials used in the experiment are alkali residue, lime and soil. The design idea of the experimental scheme is to replace part of the soil with part of the alkali residue while keeping the mass of lime unchanged. Among them, Group A0 is the control group experiment without alkali residue (12% lime). Based on the control group, five groups of experiments were designed. The specific mix ratio scheme of the experiments is shown in Table 1 Mix Ratio Design of Compaction Test for Lime Soil with Alkali Residue.

[0090] Table 1 Mix Ratio Design of Compaction Test for Lime Soil with Alkali Residue

[0091]

[0092] Step (2): Calculate the water addition required for the test group to reach the target water content.

[0093] The optimal moisture content of the control group A0 is 18.8%. Five target moisture contents are set for each of the groups A1 - A5, which are 17%, 18%, 19%, 20%, and 21% respectively. According to the formula (T 0804 - 1) in the "Test Procedures for Inorganic Binding Material Stabilized Materials in Highway Engineering JTG E51 - 2009", the water addition required for 25 groups of materials to reach the target moisture content is calculated. The water addition formula is shown in (Equation 2):

[0094] The calculation results are shown in Table 2, the material mass calculation table of alkali residue lime soil.

[0095] Table 2. Material mass calculation table of alkali residue lime soil

[0096]

[0097]

[0098] Step (3): Test the actual moisture content of the test group.

[0099] (1) Use the quartering method to divide the alkali residue, lime, soil, etc. into 5 parts respectively. Then, according to the designed proportion mass table, mix the raw materials of groups A0 - A5 respectively, and prepare specimens according to the preset five moisture contents.

[0100] (2) Spread the specimens flat in a plate, spray the water quantity calculated according to the formula on the specimens with a sprayer and mix them to make the water evenly distributed. Then put them into airtight plastic bags for infiltration for use. The infiltration time is 6 hours.

[0101] (3) Take out the infiltrated specimens and mix them again, and conduct standard light or heavy compaction tests according to the particle size of the soil particles;

[0102] (4) Use a core cutter to take out the sample, observe whether there is any missing on the surface. If there is, take specimens to repair it. Then wipe the core cutter clean and weigh the sample mass.

[0103] (5) Scrape a certain mass of specimens from the core cutter and place them in several aluminum boxes respectively, and weigh the mass of the aluminum boxes and the aluminum boxes plus the specimens. Put them in an oven for 8 hours to dry the specimens and measure their moisture content. Repeat the above steps to measure the moisture content of each ratio of groups A0 - A5.

[0104] Step (4): Calculation of the actual moisture content of each group of specimens and error analysis of the designed target moisture content

[0105] After conducting indoor light compaction tests, the errors between the actual moisture content and the target moisture content of each specimen are shown in Table 3. It can be found from the test results that there are certain errors in adding water according to the improved water addition formula in the standard, and the errors are particularly obvious.

[0106] Error between the actual moisture content and the target moisture content in Table 3

[0107]

[0108]

[0109] Step (5): Determine the correction coefficient of the water content formula

[0110] The present invention adopts the proportional coefficient method and uses the method of multiple linear regression to fit a coefficient η on the basis of the derivation formula, so that the generated new formula takes into account the influence of the alkali residue content and the added water volume corresponding to the change of the predetermined moisture content. The specific operation is as follows:

[0111] Set a multi-factor influence coefficient η, expressed as:

[0112] η = aX + bY + c

[0113] (Equation 3)

[0114] In the formula:

[0115] η - correction coefficient, the value is the added water mass obtained by correcting the theoretical formula divided by the original theoretical added water mass (g);

[0116] a - calibration parameter for the influence of alkali residue;

[0117] b - calibration parameter for the influence of the predetermined moisture content;

[0118] c - formula calibration constant;

[0119] X - alkali residue content (%);

[0120] Y - predetermined moisture content (%).

[0121] Use η to correct the formula, and the new corrected formula is:

[0122] m = η·m w (Equation 4)

[0123] In the formula:

[0124] m - theoretical added water volume after correction (g);

[0125] η - correction coefficient, the value is the added water mass obtained by correcting the theoretical formula divided by the added water mass of the derivation formula (g);

[0126] m w —— water volume to be added in the mixture (g), which is Equation 2;

[0127] Calibration of constants a, b, and c

[0128] For the solution of the multi - factor influence factor ratio η, first calculate the value k of the water addition amount calculated according to the new derivation formula m in excel, which is the value obtained by dividing the calculated water addition amount by the actual water addition mass. The results are shown in Table 4. w The value k of the water addition amount calculated according to the new derivation formula m divided by the actual water addition mass. The results are shown in Table 4.

[0129] Table 4 Calculation table of the water addition amount obtained from the theoretical formula divided by the actual water addition mass

[0130]

[0131] Create a new project table in origin and input the specific values of the two influencing factors (slag content and predetermined water content) for constructing the polynomial. The results are as Figure 1 shown.

[0132] Select the fitting function operation in the menu bar, select multiple linear regression and use origin for multiple linear fitting. When calibrating the parameters a = 0.00296, b = - 0.0362, c = 1.467, check that the F - distribution of the regression result can be controlled at about 0.05, meeting the 95% confidence level, indicating that the result is relatively reliable. Then the specific formula for η can be seen in Formula (5).

[0133] η = 0.00296X - 0.0362Y + 1.467 (Formula 5)

[0134] Then the final formula for the water addition amount to be added after correction can be seen in Formula (6).

[0135]

[0136] In the formula:

[0137] η - - correction coefficient, the value is the water addition mass obtained by correcting the theoretical formula divided by the water addition mass of the derivation formula (g);

[0138] X - - slag content (%);

[0139] Y - - predetermined water content (%);

[0140] m n - - the mass of soil in the lime - soil with slag (g), the initial water content is w n (%);

[0141] m c - - the mass of lime in the lime - soil with slag (g), the initial water content is w c (%);

[0142] m k - - the mass of slag in the lime - soil with slag (g), the initial water content is w k (%);

[0143] w - - the water content of the lime - soil with slag required to be achieved (%).

[0144] Step (6): Verification of correction coefficient accuracy

[0145] (1) Result analysis

[0146] Calculate the new water addition amount by the correction formula (6), conduct error analysis with the actual water content, and compare it with the error analysis of the water addition amount of the original formula. The results are shown in Table 5.

[0147] Table 5 Comparison of water addition mass errors between the new and old formulas

[0148]

[0149]

[0150] In order to compare and analyze the improvement of the error accuracy in water content between the original water addition formula (2) and the corrected water addition formula (6), conduct an analysis of the improvement in error value accuracy by comparing the error in water addition of formula (6) with the error obtained after water addition using formula (2). The results are shown in Table 6.

[0151] Table 6 Degree of accuracy improvement

[0152]

[0153]

[0154] It can be found from the above analysis that the correction formula has a relatively high improvement in the accuracy of the original derivation theoretical formula and can better meet the calculation of the water addition amount of alkali residue lime soil.

[0155] (2) Experimental verification

[0156] In order to verify the accuracy of the correction formula, the present invention adopts a verification experimental group. Arbitrarily select a predetermined moisture content between 17% - 21%, and arbitrarily select within the range of 0 - 30% of the alkali residue content ratio. The present invention selects two intermediate moisture contents of 18.5% and 20.5% to determine the verification experimental scheme for this time, as shown in Table 7.

[0157] Table 7 Design scheme of verification test

[0158]

[0159] The results obtained by repeating the above experimental steps are shown in Table 8.

[0160] Table 8 Results of verification test

[0161]

[0162]

[0163] The verification test found that after using the correction formula for 6 groups of specimens, the average accuracy increased by 24.27%. The effect of the correction formula is significant, indicating that the correction formula of the present invention is correct and has practical application value.

Claims

1. A method for modifying the water addition formula of specimens in the compaction test of roadbed alkali residue lime soil, characterized in that: It includes the following steps: (1) Determine the ratio of alkali residue lime soil, use part of the alkali residue to replace part of the soil, and keep the mass of lime unchanged; (2) Calculate the water addition amount required to reach the target water content; select multiple groups of materials with different alkali residue dosages, test the natural water contents of the alkali residue and the soil, and calculate the water addition amounts required for multiple groups of materials to reach the target water content; the water addition formula is: m w — Water content to be added in alkali residue lime soil (g); m n — Mass (g) of soil in lime soil with soda residue, and natural water content of soil is w n (%) m c — mass (g) of lime in lime-slag soil, natural water content of lime is w c (%); m k — mass (g) of soda residue in soda residue lime soil, natural water content of soda residue is w k (%); w—the target water content (%) of the required alkali residue lime soil; (3) Test the actual water content of the test group; (4) Analyze the error between the calculated actual water content of each group of specimens and the designed target water content; (5) Design the correction coefficient of the water addition formula and calibrate the parameters; add a correction coefficient η to the basis of formula (2), and the expression of η is as follows: η = aX + bY + c (formula 3) η—the correction coefficient, and the value is the added water mass obtained by modifying the theoretical formula divided by the original theoretical added water mass (g); a—the calibration parameter affected by the alkali residue; b—the calibration parameter affected by the predetermined water content; c—the formula calibration constant; X—the alkali residue content (%); Y—the predetermined water content (%); Use η to modify the formula, and the new modified formula is: m = η·mw (formula 4) m—the modified theoretical water addition amount (g); η—the correction coefficient, and the value is the added water mass obtained by modifying the theoretical formula divided by the added water mass of the derivation formula (g); m w —— The amount of water to be added to the mixture (g); (6) Verify the accuracy of the correction coefficient of the water addition formula.

2. The method for modifying the water addition formula of specimens in the compaction test of roadbed alkali residue lime soil according to claim 1, characterized in that: The process of step (3) is as follows: (3.1) Dry and crush the lime and alkali residue, and sieve them with a standard sieve; (3.2) Prepare the alkali residue lime soil mixture for multiple groups of materials according to the preset target water content, spray the calculated water addition amount of water onto the mixture, and put the mixture added with water into an airtight bag and immerse it in water for soaking and moistening; (3.3) Take out the soaked mixture and remix it, and conduct standard light or heavy compaction tests according to the particle size of the soil particles; (3.4) Use a core cutter to take samples, weigh the mass of the alkali residue lime soil inside the sample, and calculate the dry density of the sample; (3.5) Scrape the specimen from the core cutter, dry the specimen, and test the average water content of the specimen; repeat the above steps to measure the actual water content of each group of specimens.

3. The method for modifying the water addition formula of specimens in the compaction test of roadbed alkali residue lime soil according to claim 1, characterized in that: In step (2), the natural water contents of the alkali residue and the soil are tested by the drying method.

4. The method for modifying the water addition formula of specimens in the compaction test of roadbed alkali residue lime soil according to claim 2, characterized in that: The lime in step (3.1) is anhydrous lime.

5. The method for modifying the water addition formula of specimens in the compaction test of roadbed alkali residue lime soil according to claim 2, characterized in that: In step (3.1), after drying and crushing the lime and alkali residue, sieve them with a 4.75 mm standard sieve.

6. The method for modifying the water addition formula of specimens in the compaction test of roadbed alkali residue lime soil according to claim 2, characterized in that: In step (3.4), samples are taken using a core cutter. If there are any deficiencies on the surface of the sample, specimens are taken for repair.

7. According to the method for correcting the water addition formula of specimens in the roadbed lime soil compaction test as described in claim 2, it is characterized in that: In step (3.5), the specimens are scraped from the core cutter and placed in boxes respectively. Then, the mass of the box and the box with the specimens is weighed, the specimens are dried, and the average moisture content of the specimens is measured.

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