A method for predicting the strength of a cement-stabilized soil and related apparatus
By constructing a prediction model for the unconfined compressive strength of cement-stabilized soil, and utilizing the physical properties and test parameters of the stabilized soil, the problem of utilizing surplus soil during construction was solved, and efficient and precise construction quality control was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- STATE GRID ECONOMIC TECH RES INST CO LTD
- Filing Date
- 2026-03-19
- Publication Date
- 2026-07-10
AI Technical Summary
Existing technologies are unable to effectively utilize construction waste soil with poor soil properties, and the high cost of on-site testing leads to low construction efficiency and an inability to meet construction quality requirements.
By constructing a prediction model for the unconfined compressive strength of cement-stabilized soil, and using the physical properties and experimental parameters of the stabilized soil, a normalized compressive strength index for the unconfined compressive strength of cement-stabilized soil is established. The prediction model formula is then fitted to achieve rapid prediction of the strength of cement-stabilized soil.
It achieves high-precision prediction of the strength of cement-stabilized soil with an error of less than 0.15 MPa, reducing on-site testing costs and improving construction efficiency and quality.
Smart Images
Figure CN122369657A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of building materials, and in particular to a method and apparatus for predicting the strength of cement-stabilized soil. Background Technology
[0002] The construction of power grid projects generates a certain amount of surplus construction soil. This soil is often treated as waste, and the process of handling it incurs additional construction costs due to transportation and site storage, while also wasting land resources due to long-term occupation of the land. In actual projects, surplus construction soil with good soil properties can be rationally utilized, such as as filling materials. However, the resource utilization of surplus construction soil with poor soil properties has always been a challenge in power grid construction. Under the national dual-carbon development goals, if these surplus construction soils are treated using cement solidification methods, the treated soil can be transformed into engineering construction materials with practical value.
[0003] Unconfined compressive strength testing is a primary method for evaluating the suitability of solidified and improved soil in foundation treatment. Given the complex nature of construction waste soil, there is an urgent need to explore how to establish a predictive model and method for the unconfined compressive strength of cement-solidified soil based on the basic physical properties of cement in the solidification scheme. This would reduce on-site testing costs and provide an efficient solution for treating construction waste soil. Summary of the Invention
[0004] This invention provides a method and related apparatus for predicting the strength of cement-stabilized soil. By conducting experiments based on the physical properties of the stabilized soil, solidification test parameters, and unconfined compressive strength of the stabilized soil, a normalized unconfined compressive strength index for cement-stabilized soil is constructed. This index is then fitted with the experimental values of the unconfined compressive strength of the stabilized soil to construct a prediction model formula for the unconfined compressive strength of cement-stabilized soil with this strength index as the sole predictor variable. This method can rapidly predict the strength of cement-stabilized soil based on different physical properties and solidification test parameters, reducing on-site testing costs and improving construction efficiency and quality.
[0005] To address the aforementioned technical problems, one objective of this invention is to provide a method for predicting the strength of cement-stabilized soil, comprising the following steps: (1) Prepare cement-stabilized soil samples using geotechnical testing methods, and determine the normalized index I of unconfined compressive strength of cement-stabilized soil based on the solidification test parameters and basic physical property indicators of the cement-stabilized soil samples. (2) Conduct an unconfined compressive strength test on the cement-stabilized soil sample to determine the unconfined compressive strength of the cement-stabilized soil. Test values; (3) Place the I and The test values are fitted into the formula according to the following formula (1), and the values of a and b are calculated. Substitute them into formula (2) to obtain the prediction model formula, which can be used to predict the unconfined compressive strength of cement-solidified soil. (1); (2); In the formula: The unconfined compressive strength test value of cement-stabilized soil is expressed in MPa. The value is the predicted unconfined compressive strength of cement-stabilized soil, in MPa. x I represents the normalized compressive strength index of cement-stabilized soil without lateral confinement; a and b are experimental fitting parameters.
[0006] In some implementations, in step (1), the curing test parameters include cement content and curing age.
[0007] In some embodiments, in step (1), the basic physical property index includes at least one of the following: water content, specific gravity, bulk density, and porosity of cement-stabilized soil.
[0008] In some implementations, in step (1), the basic physical property index is porosity, which is calculated based on the cement content, total curing age and porosity and according to the following formula (3) to obtain the normalized index I of unconfined compressive strength of cement-cured soil. (3); In the formula: I(n) t (c,t) represents the normalized index of unconfined compressive strength of cement-stabilized soil; n t denoted as dimensionless value for porosity of cement-stabilized soil; c is dimensionless value for mass fraction of cement content; t is the total curing age of the stabilized soil, in days.
[0009] In some embodiments, the porosity of the cement-stabilized soil is calculated based on the water content, specific gravity, and bulk density of the cement-stabilized soil, and the porosity of the cement-stabilized soil is calculated according to the following formulas (4) and (5). (4); (5); In the formula: e t G is the dimensionless value of the void ratio of the solidified soil. st w is the dimensionless value of the specific gravity of cement-stabilized soil. t γ is the dimensionless value of the moisture content of cement-stabilized soil; w The specific weight of water, in kN / m³ 3 ;γ t This refers to the unit weight of cement-stabilized soil, in kN / m³. 3 ;nt This is the dimensionless value of the porosity of cement-stabilized soil.
[0010] In some embodiments, in step (1), the geotechnical test method includes the following steps: after drying the cement and construction waste soil respectively, the cement, construction waste soil and water are mixed evenly, poured into a mold and compacted, cured at room temperature and then demolded, and cured in a constant temperature and humidity environment until the set curing age is obtained to prepare a cement-cured soil sample.
[0011] In some implementations, in step (3), R in equations (3) and (4) 2 ≥0.95.
[0012] In some implementations, in step (3), the I and q of the same maintenance age are... u The experimental values are fitted into a formula according to equation (1), and the values of a and b are calculated and substituted into equation (2) to obtain the prediction model formula.
[0013] When the total curing age is constant, the I and I of the solidified soil There is a relatively clear nonlinear relationship between the experimental values, which can be well described by a power function. A prediction model formula is established using samples with the same total maintenance age, and the resulting fitting model parameters are relatively simple and easy to use.
[0014] To address the aforementioned technical problems, a second objective of this invention is to provide a terminal device comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the method for predicting the strength of cement-stabilized soil.
[0015] To address the aforementioned technical problems, a third objective of this invention is to provide a computer-readable storage medium comprising a stored computer program, wherein the computer program, when running, controls the device containing the computer-readable storage medium to execute the method for predicting the strength of cement-stabilized soil.
[0016] Compared with the prior art, the present invention has the following beneficial effects: This application constructs a normalized compressive strength index for cement-stabilized soil based on the relationship between solidified soil physical properties, solidification test parameters, and unconfined compressive strength of solidified soil. This index is then fitted with the unconfined compressive strength test values of solidified soil to construct a predictive model formula for the unconfined compressive strength of cement-stabilized soil. This model can rapidly predict the strength of cement-stabilized soil based on different solidified soil physical properties and solidification test parameters. Furthermore, the absolute error of the unconfined compressive strength is below 0.15 MPa, demonstrating high prediction accuracy. This meets construction requirements, reduces on-site testing costs, and improves construction efficiency and quality. Attached Figure Description
[0017] Figure 1 This is a flowchart illustrating a method for predicting the strength of cement-stabilized soil in Embodiment 1 of the present invention. Figure 2 The formula and curve for predicting the unconfined compressive strength of cement-cured soil samples prepared during a 14-day curing period in Example 1 of this invention; Figure 3 The formula and curve of the prediction model for the unconfined compressive strength of cement-solidified soil prepared with a curing period of 28 days in Example 1 of this invention; Figure 4 The formula and curve of the prediction model for the unconfined compressive strength of cement-cured soil prepared during a 60-day curing period in Example 1 of this invention are shown. Detailed Implementation
[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0020] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0021] As used in this article: In these embodiments, unless otherwise specified, the portions and percentages are all by weight.
[0022] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).
[0023] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", etc., indicating orientation or positional relationship are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.
[0024] To further illustrate the present invention, the following detailed description is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention. The sources of the raw materials used in the embodiments and comparative examples of this application are as follows. Unless otherwise specified, all raw materials used are commercially available, and the same raw materials were used in parallel experiments.
[0025] Example 1 A method for predicting the strength of cement-stabilized soil, such as Figure 1 As shown, it includes the following steps: (1) Cement-solidified soil samples were prepared using geotechnical testing methods. Cement and construction waste soil were dried in an oven at 105℃ for 6 hours. Cement was placed in the mixing pot of a planetary mixer and stirred slowly until uniform. Construction waste soil was added slowly and stirred until uniform again. Distilled water was added slowly and stirred until uniform. The mixture was poured into a stainless steel cylindrical mold through a funnel and compacted in three layers. Plastic wrap was used to cover the top surface of the specimen to prevent moisture loss. The specimen was demolded after curing at room temperature for 3 days and then transferred to a constant temperature and humidity curing chamber at 23℃ to continue curing until the set test age. The three basic physical property indicators of cement-solidified soil sample were determined: moisture content, specific gravity of solidified soil, and bulk density of solidified soil. The porosity of the sample was calculated according to the following formulas (1) and (2) based on the physical property indicators. Three parallel samples were prepared for each test point and the average value was taken. The test results are shown in Table 1-3 below. (1); (2); In the formula: e t G is the dimensionless value of the void ratio of the solidified soil. st w is the dimensionless value of the specific gravity of cement-stabilized soil. t γ is the dimensionless value of the moisture content of cement-stabilized soil; w The specific weight of water, in kN / m³ 3 ;γ t This refers to the unit weight of cement-stabilized soil, in kN / m³. 3 ;n t This is the dimensionless value of the porosity of cement-stabilized soil. (2) Based on the cement content, total curing age and porosity test results, the normalized compressive strength index of cement-cured soil under the corresponding curing scheme is calculated according to the following formula (3). The test results are shown in Table 1-3 below. (3); In the formula: I(n) t (c, t) represents the normalized unconfined compressive strength index of cement-stabilized soil; n t denoted as dimensionless value for porosity of cement-stabilized soil; c is the dimensionless value for mass fraction of cement content; t is the total curing age of the stabilized soil, in days. (3) Unconfined compressive strength test was conducted on cement-stabilized soil samples using an electro-hydraulic universal testing machine. A hydraulic jack was used to drive the connecting rod to apply a vertical load to the specimen. The load was collected in real time by a 10 kN range (accuracy ±0.001 kN) pressure sensor. The displacement sensor built into the connecting rod synchronously recorded the specimen deformation data. The specimen was placed on the bottom plate of the testing machine. The power of the testing machine was turned on and the bottom plate was slowly moved upward. The upward movement was stopped when the top surface of the specimen was about to contact the top plate. The specimen position was checked to be in the center of the loading plate and the top and bottom surfaces were parallel to the loading plate. Loading was then started. The test adopted the displacement control mode. In the initial stage, the loading rate was 0.1 mm / min until the sensor reading reached 0.5 kN to ensure that the specimen and the sensor were in contact. Then the loading rate was adjusted to 0.08 mm / min for formal testing. The specimen failure was considered when the force-displacement curve showed a peak value and the force value decreased by more than 30% of the maximum load. At this time, the test was terminated. The unconfined compressive strength test value of cement-stabilized soil was determined by dividing the ultimate bearing capacity by the cross-sectional area of the specimen. The test results are shown in Table 1-3 below; (4) Using the least squares method, the above methods are used to obtain I(n) within the same total maintenance period. t (c,t) and The experimental values are fitted according to the following equation (4), which can be implemented using Python programming, and ensures that the R-value of equation (4) is within the range of 4. 2 ≥0.95, the calculated values of prediction model parameters a and b are shown in Table 4 below. Substituting a and b into equation (5) yields the prediction model formula, which is used to predict the unconfined compressive strength of cement-stabilized soil. The prediction model formula and curve are shown below. Figure 2-4 As shown; (4); (5); In the formula: q u ʹ represents the unconfined compressive strength of cement-stabilized soil, in MPa. The value is the predicted unconfined compressive strength of cement-stabilized soil, in MPa. xI(n) is the normalized index of unconfined compressive strength of cement-stabilized soil. t (c, t); a and b are experimental fitting parameters.
[0026] Table 1 - Basic physical properties of cement-stabilized soil with different cement contents at a total curing age of 14 days. Table 2 - Basic physical properties of cement-stabilized soil with different cement contents at a total curing age of 28 days. Table 3 - Basic physical properties of cement-stabilized soil with different cement contents at a total curing age of 60 days. Table 4 - Prediction model parameters a and b for the unconfined compressive normalized strength of cement-stabilized soil at different total curing ages. Example 2 The verification test of the above-mentioned method for predicting the strength of cement-stabilized soil includes the following steps: The predicted values of unconfined compressive strength of cement-stabilized soil were calculated using the prediction model formula constructed according to different total curing ages from the 15 experiments in Example 1. and the predicted value Compared with test values A comparison was made to verify the accuracy of the prediction model, and the results are shown in Table 5 below.
[0027] Table 5 - Comparison of unconfined compressive strength test values and predicted values for 15 cement-stabilized soil samples in Example 1 Example 3 The verification test of the above-mentioned method for predicting the strength of cement-stabilized soil includes the following steps: (1) Prepare cement-stabilized soil samples with a cement content c of 16% according to the method in step (1) of Example 1, and test the three basic physical properties of moisture content, specific gravity, and unit weight, as well as the unconfined compressive strength test value at total curing ages of 14 days, 28 days, and 60 days. The porosity of the sample was calculated using equations (1) and (2). n t And calculate the normalized strength index I(n) of the unconfined compressive strength of cement-stabilized soil according to formula (3). t The results are shown in Table 5 below; (2) The porosity of the sample n t and the normalized index of unconfined compressive strength I(n) of cement-stabilized soil tSubstituting (c, t) into the prediction model formula corresponding to the total maintenance age in equation (5) of Example 1, the predicted value of unconfined compressive strength is calculated. and the test value of step (1) The accuracy of the prediction model was verified by comparison, and the results are shown in Table 6 below.
[0028] Table 6 - Basic physical properties of cement-stabilized soil in step (1) of Example 3 Table 7 - Comparison of test and predicted values of unconfined compressive strength of cement-stabilized soil in Example 3 As shown in Tables 5 and 7 above, for multiple specimens with different total curing ages, the absolute value of the error in the predicted value of the unconfined compressive strength is all below 0.15 MPa, indicating that the prediction model proposed in Example 1 of this application has sufficient accuracy and can meet engineering needs.
[0029] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.
Claims
1. A method for predicting the strength of cement-stabilized soil, characterized in that, Includes the following steps: (1) Prepare cement-stabilized soil samples using geotechnical testing methods, and determine the normalized index I of unconfined compressive strength of cement-stabilized soil based on the solidification test parameters and basic physical property indicators of the cement-stabilized soil samples. (2) Conduct an unconfined compressive strength test on the cement-stabilized soil sample to determine the unconfined compressive strength of the cement-stabilized soil. Test values; (3) Place the I and The test values are fitted into the formula according to the following formula (1), and the values of a and b are calculated. Substitute them into formula (2) to obtain the prediction model formula, which can be used to predict the unconfined compressive strength of cement-solidified soil. （1）； （2）； In the formula: The unconfined compressive strength test value of cement-stabilized soil is expressed in MPa. The value is the predicted unconfined compressive strength of cement-stabilized soil, in MPa. x I represents the normalized compressive strength index of cement-stabilized soil without lateral confinement; a and b are experimental fitting parameters.
2. The method for predicting the strength of cement-stabilized soil as described in claim 1, characterized in that, In step (1), the curing test parameters include cement content and curing age.
3. The method for predicting the strength of cement-stabilized soil as described in claim 2, characterized in that, In step (1), the basic physical property index includes at least one of the following: water content, specific gravity, bulk density, and porosity of cement-stabilized soil.
4. The method for predicting the strength of cement-stabilized soil as described in claim 3, characterized in that, In step (1), the basic physical property index is porosity. Based on the results of cement content, total curing age and porosity, the normalized index of unconfined compressive strength of cement-cured soil I is calculated according to the following formula (3). （3）； In the formula: I(n) t (c,t) represents the normalized index of unconfined compressive strength of cement-stabilized soil; n t denoted as dimensionless value for porosity of cement-stabilized soil; c is dimensionless value for mass fraction of cement content; t is the total curing age of the stabilized soil, in days.
5. The method for predicting the strength of cement-stabilized soil as described in claim 4, characterized in that, The porosity of the cement-stabilized soil is calculated based on the water content, specific gravity, and bulk density of the cement-stabilized soil. The porosity of the cement-stabilized soil is calculated according to the following formulas (4) and (5). （4）； （5）； In the formula: e t G is the dimensionless value of the void ratio of the solidified soil. st w is the dimensionless value of the specific gravity of cement-stabilized soil. t γ is the dimensionless value of the moisture content of cement-stabilized soil; w The specific weight of water, in kN / m³ 3 ;γ t This refers to the unit weight of cement-stabilized soil, in kN / m³. 3 ;n t This is the dimensionless value of the porosity of cement-stabilized soil.
6. The method for predicting the strength of cement-stabilized soil as described in claim 1, characterized in that, In step (1), the geotechnical test method includes the following steps: after drying the cement and construction waste soil respectively, the cement, construction waste soil and water are mixed evenly, poured into the mold and compacted, cured at room temperature and then demolded, and cured in a constant temperature and humidity environment until the set curing age is obtained to prepare cement-solidified soil samples.
7. The method for predicting the strength of cement-stabilized soil as described in claim 1, characterized in that, In step (3), R in equations (3) and (4) 2 ≥0.
95.
8. The method for predicting the strength of cement-stabilized soil as described in claim 1, characterized in that, In step (3), the I and the same maintenance age are used. The experimental values are fitted into a formula according to equation (1), and the values of a and b are calculated and substituted into equation (2) to obtain the prediction model formula.
9. A terminal device, characterized in that, The method includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the method for predicting the strength of cement-stabilized soil as described in any one of claims 1-8.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform the method for predicting the strength of cement-stabilized soil as described in any one of claims 1-8.