A method and system for predicting the static strength parameters of soil considering oversized blocks

Abstract

The application discloses a kind of prediction method and system considering the static strength parameter of soil body of super-diameter block stone, and the method of the application is combined with the physical test data of static triaxial test and the numerical test data of numerical simulation, and the grading of soil material is quantitatively characterized using fractal theory.The superposition form of fine particles and coarse particles is used to present the strength parameter prediction formula of the static strength parameter of the soil sample of accumulation body, and the relationship between the fractal dimension of each particle size interval and the test value of the static strength parameter of the accumulation body soil is used to determine the prediction formula of the static strength parameter of the soil sample of accumulation body.The application also provides a system for implementing the prediction method of the static strength parameter of the soil body considering the super-diameter block stone.The method of the application overcomes the influence of super-diameter block stone on the prediction of the static strength of soil, provides reliable prediction value of the static strength parameter of the soil body considering the super-diameter block stone, and provides more reliable mechanical parameter support for engineering design and construction.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of geotechnical test, and particularly relates to a method and system for predicting static strength parameters of soil considering oversized stones. BACKGROUND

[0002] In the field of geotechnical engineering, accurately predicting the static strength parameters of soil materials is of great significance to engineering design, construction, and stability analysis. The traditional method for testing the static strength parameters of soil materials is mainly based on conventional geotechnical tests. At the same time, due to the size limitation of the sample, oversized stones in the soil material need to be removed during the geotechnical test. However, in actual engineering, oversized stones exist in many accumulation bodies of soil, which have a significant impact on the overall static strength characteristics of the soil. However, the traditional test method often fails to fully consider the effect of oversized stones. SUMMARY

[0003] In view of the above shortcomings of the prior art, one of the purposes of the present application is to provide a method for predicting the static strength parameters of soil considering oversized stones, so as to achieve the purpose of predicting the static strength of oversized stones.

[0004] The second purpose of the present application is to provide a system for implementing the method for predicting the static strength parameters of soil considering oversized stones.

[0005] The present application provides a method for predicting the static strength parameters of soil considering oversized stones, comprising the following steps:

[0006] S1. Perform a static triaxial test to obtain a stress-strain relationship curve of the accumulation body soil sample without considering oversized stones, and then determine the static strength parameter test value under the corresponding working condition according to the obtained stress-strain relationship curve of the accumulation body soil sample without considering oversized stones;

[0007] S2. Based on the particle mass-particle size fractal model of the fractal theory, fit the gradation curve in the static triaxial test in step S1 to obtain the fractal dimension of the preset particle size interval, and then obtain a first prediction formula of the static strength parameter of the accumulation body soil sample according to the relationship between the obtained fractal dimension of the preset particle size interval and the static strength parameter test value obtained in step S1, and obtain the first predicted value of the static strength parameter of the accumulation body under different maximum stone sizes based on the formula;

[0008] S3. Based on the stress-strain relationship curve of the accumulation body soil sample without considering oversized stones obtained in step S1, a static triaxial sample model of the accumulation body soil sample is constructed, and numerical simulation calibration is performed to obtain the mesoscopic contact parameters of the numerical model; according to the obtained mesoscopic contact parameters of the numerical model, numerical test is performed by using the equivalent replacement method to obtain the first test value of the static strength parameter of the accumulation body under different maximum stone sizes without considering oversized stones.

[0009] S4. Based on the first predicted value of the static strength parameter of the accumulation body under different maximum block stone size conditions obtained in step S2, it is compared with the first test value of the static strength parameter of the accumulation body under different maximum block stone size conditions obtained in step S3 to make a judgment. If the judgment fails, the particle size fractal value of the super-diameter block stone non-scaling interval is introduced to modify the first prediction formula of the static strength parameter of the accumulation body soil sample obtained in step S2, otherwise the first prediction formula of the static strength parameter of the accumulation body soil sample is directly used to obtain the second prediction formula of the static strength parameter of the soil body considering the super-diameter block stone;

[0010] S5. The static triaxial test is carried out by using a large-scale triaxial instrument to obtain the second test value of the static strength parameter of the accumulation body under different maximum block stone size conditions considering the super-diameter block stone. Based on the second prediction formula of the static strength parameter of the soil body, the second predicted value of the static strength parameter of the accumulation body considering the super-diameter block stone is obtained, which is compared with the second test value of the static strength parameter of the accumulation body to make a reliability judgment on the current second prediction formula of the static strength parameter of the soil body considering the super-diameter block stone. If the judgment is passed, the next step is entered, otherwise the current second prediction formula of the static strength parameter of the soil body considering the super-diameter block stone is modified and updated, and step S5 is repeated;

[0011] S6. According to the second prediction formula of the static strength parameter of the soil body considering the super-diameter block stone obtained in step S4, the prediction of the static strength parameter of the soil body considering the super-diameter block stone is completed.

[0012] Step S1 includes the following steps:

[0013] The static triaxial test is carried out, the cylindrical soil sample is prepared according to the compaction degree and other conditions required by the test, and is wrapped with rubber film and placed in the pressure chamber; the particle size of the accumulation body soil sample in the static triaxial test is not more than 20mm;

[0014] The sample is loaded into the static triaxial instrument, the bottom and top water-permeable stones are connected with the drainage system, and the pressure chamber is sealed;

[0015] The pressure of the pressure chamber is adjusted to apply a predetermined confining pressure to simulate the in-situ stress condition;

[0016] The sample is subjected to drainage consolidation, and the volume deformation of the sample is recorded until it is stable;

[0017] The sample is subjected to axial stress at a constant rate, and the axial stress and strain of the sample are synchronously collected by the sensor to obtain the stress-strain relationship curve of the accumulation body soil sample without considering the super-diameter block stone;

[0018] According to the obtained stress-strain relationship curve of the soil sample of the accumulation body not considering the oversized block stone, test values of static strength parameters under different confining pressures and different stone contents are determined; the test values of the static strength parameters are internal friction angles of the accumulation body; the confining pressure is a constant pressure preset in the test process; and the stone content is a percentage of the mass of the soil sample with a particle size greater than 2 mm in the total test sample.

[0019] Preferably, the confining pressure is 100 Kpa, 150 Kpa, and 200 Kpa, respectively; and the stone content is 25%, 45%, and 65%, respectively.

[0020] The step S2 specifically includes the following steps:

[0021] The particle mass-particle size fractal model based on the fractal theory is used to fit the grading curve of the fine particles and the coarse particles in the static triaxial test in step S1, so as to obtain the fractal dimension in a preset particle size interval; the particle size of the fine particles is less than 2 mm; and the particle size of the coarse particles ranges from 2 mm to 20 mm.

[0022] According to the relationship between the obtained fractal dimension in the preset particle size interval and the test values of the static strength parameters obtained in step S1, a first prediction formula of the static strength parameters of the soil sample of the accumulation body is obtained.

[0023] Based on the formula, a first prediction value of the static strength parameters of the accumulation body under the condition of different maximum block stone sizes is obtained.

[0024] The particle mass-particle size fractal model based on the fractal theory is expressed by the following formula:

[0025]

[0026] In the formula, R is a preset particle diameter; is the mass of the particle with a particle diameter r less than the preset particle diameter R; and M is the total mass of the particles. is the maximum particle size; and D is the fractal dimension.

[0027] The grading curve is a relationship between the percentage of each particle size soil sample in the test sample in the static triaxial test and the cumulative mass percentage of the soil sample with a particle size less than the particle size.

[0028] The first prediction formula of the static strength parameters of the soil sample of the accumulation body is expressed by the following formula:

[0029]

[0030] In the formula, φ is the internal friction angle of the accumulation body; is the particle fractal dimension in the fine particle scale-invariant interval.​ is the particle fractal dimension value of the coarse particle non-scaling interval; is a function relationship between the particle fractal dimension value of the fine particle non-scaling interval and the test value of the static strength parameter of the soil body; is a function relationship between the particle fractal dimension value of the coarse particle non-scaling interval and the test value of the static strength parameter of the soil body; and The test value of the static strength parameter of the soil body obtained by the step S1 and the fractal dimension of the preset particle interval obtained by the step S2 are fitted to obtain.

[0031] The step S3 comprises the following steps:

[0032] In the numerical simulation software, a static triaxial sample model of the soil body is constructed;

[0033] Based on the stress-strain relationship curve of the step S1, the numerical simulation calibration is performed to obtain the mesoscopic contact parameters of the model;

[0034] According to the mesoscopic contact parameters, the equal replacement method is used to change the maximum size of the block stone in the sample under the condition that the block stone content in the sample model is unchanged, the numerical test is carried out, and the numerical first test value of the static strength parameter of the soil body under the condition of different maximum block stone sizes is obtained.

[0035] The mesoscopic contact parameters include effective modulus, stiffness ratio, friction coefficient and anti-rotation friction coefficient.

[0036] The step S4 comprises the following steps:

[0037] The first error change relationship with the stone content is obtained by comparing the numerical first predicted value of the static strength parameter of the soil body with the numerical first test value of the static strength parameter of the soil body under the condition of different maximum block stone sizes; the first error change relationship with the stone content includes linear form and nonlinear form; the first error is the difference between the numerical first test value of the static strength parameter of the soil body and the numerical first predicted value of the static strength parameter of the soil body; if the error between the numerical first predicted value of the static strength parameter of the soil body and the numerical first test value of the static strength parameter of the soil body is less than or equal to 10%, the static strength parameter first prediction formula of the soil body is directly used as the soil static strength parameter second prediction formula considering the super-diameter block stone, otherwise the following step is performed:

[0038] The soil body is divided into three parts of fine particles, coarse particles and super-diameter block stones; the particle size of the fine particles is less than 2mm; the particle size range of the coarse particles is 2mm-20mm; the particle size of the super-diameter block stone is greater than 20mm;

[0039] According to the particle mass-particle size fractal model of the fractal theory, the grading curve of the three parts of the fine particles, the coarse particles and the oversized block stones of the part of the accumulated body soil is fitted to obtain the particle size fractal dimension value of the non-scaling interval of the oversized block stones;

[0040] According to the first error change relation with the stone content, the particle size fractal dimension value of the non-scaling interval of the oversized block stones is used to modify the first prediction formula of the static strength parameter of the accumulated body soil sample to obtain a second prediction formula of the static strength parameter of the soil considering the oversized block stones, which is expressed by the following formula:

[0041]

[0042] Among them, is the internal friction angle of the accumulated body; is the particle fractal dimension value of the non-scaling interval of the fine particles; is the particle size fractal dimension value of the non-scaling interval of the coarse particles after modification; is the functional relation between the particle fractal dimension value of the non-scaling interval of the fine particles and the test value of the static strength parameter of the accumulated body soil; is the functional relation between the particle size fractal dimension value of the non-scaling interval of the coarse particles after modification and the test value of the static strength parameter of the accumulated body soil.

[0043] Under the premise of ensuring that the block stone content in the sample is unchanged, the equivalent replacement method is used to change the maximum size of the block stone in the sample. When only the maximum particle size of the block stone is changed, the particle size fractal dimension value of the non-scaling interval of the fine particles of the accumulated body soil remains unchanged, while the particle size fractal dimension value of the non-scaling interval of the coarse particles changes. Therefore, the particle size fractal dimension value of the non-scaling interval of the oversized block stone is introduced to modify the particle size fractal dimension value of the non-scaling interval of the coarse particles in the first prediction formula of the static strength parameter of the accumulated body soil sample, which is specifically:

[0044] According to the first error change relation with the stone content, the correction function of the particle size fractal dimension value of the non-scaling interval of the coarse particles is obtained, and the correction function takes the particle size fractal dimension value of the non-scaling interval of the oversized block stone as the independent variable;

[0045] According to the correction function of the particle size fractal dimension value of the non-scaling interval of the coarse particles, the particle size fractal dimension value of the non-scaling interval of the coarse particles in the first prediction formula of the static strength parameter of the accumulated body soil sample is modified, which is expressed by the following formula:

[0046]

[0047] Among them, is the particle size fractal dimension value of the non-scaling interval of the coarse particles after modification; is the particle size fractal dimension value of the non-scaling interval of the coarse particles; is the particle size fractal dimension value of the non-scaling interval of the oversized block stone; is the correction function of the particle size fractal dimension value of the non-scaling interval of the coarse particles. The first error variation with the stone content is obtained, including a linear form and a nonlinear form;

[0048] Finally, the second prediction formula of the static strength parameter of the soil body considering the oversized block stone is obtained.

[0049] Step S5 specifically includes the following steps:

[0050] The second test value of the static strength parameter of the accumulation body under the condition of considering the oversized block stone is obtained through the static triaxial test by using the large-scale triaxial instrument;

[0051] Preferably, the large-scale triaxial instrument adopts a large-scale triaxial instrument capable of bearing a cylindrical sample with a size of 300mm*600mm.

[0052] The second prediction value of the static strength parameter of the accumulation body considering the oversized block stone is obtained based on the second prediction formula of the static strength parameter of the soil body;

[0053] The second prediction value of the static strength parameter of the accumulation body considering the oversized block stone is compared with the second test value of the static strength parameter of the accumulation body, and the second error variation with the stone content is obtained; if the error between the second prediction value of the static strength parameter of the accumulation body considering the oversized block stone and the second test value of the static strength parameter of the accumulation body is less than or equal to 10%, the next step is entered, otherwise the current second prediction formula of the static strength parameter of the soil body considering the oversized block stone is updated and modified, and step S5 is repeated; the second error variation with the stone content includes a linear form and a nonlinear form;

[0054] The current second prediction formula of the static strength parameter of the soil body considering the oversized block stone is updated and modified, specifically as follows:

[0055] The accumulation body soil is divided into three parts, i.e., fine particles, coarse particles and oversized block stones;

[0056] According to the particle mass-particle size fractal model of the fractal theory, the grading curve of the part of the accumulation body soil is fitted, and the particle size fractal value of the non-scaling interval of the oversized block stone is obtained.

[0057] According to the second error variation with the stone content, the parameter in the second prediction formula of the static strength parameter of the accumulation body soil sample is modified based on the particle size fractal value of the non-scaling interval of the oversized block stone, as a new second prediction formula of the static strength parameter of the accumulation body soil sample.

[0058] Step S6 specifically includes the following steps: obtaining the fine particle non-scaling interval particle size fractal value, the coarse particle non-scaling interval particle size fractal value and the oversized block stone non-scaling interval particle size fractal value of the to-be-predicted oversized block stone soil body;

[0059] Based on the second prediction formula for the static strength parameter of the soil sample obtained in step S5, the static strength parameter of the oversized boulders to be predicted is predicted, and the predicted value of the static strength parameter of the oversized boulders to be predicted is obtained.

[0060] The present invention also provides a system for implementing the method for predicting the static strength parameters of soil considering oversized boulders, including a data acquisition module, a first prediction formula construction module for static strength parameters of soil, a first experimental value acquisition module for static strength parameters of accumulated body, a second prediction formula construction module for static strength parameters of soil, a formula reliability judgment and update module, and a static strength parameter prediction module.

[0061] The data acquisition module conducts static triaxial tests to obtain the stress-strain relationship curve of the soil sample without considering oversized boulders. Based on the obtained stress-strain relationship curve of the soil sample without considering oversized boulders, the test values ​​of static strength parameters under the corresponding working conditions are determined, and the data is uploaded to the first prediction formula construction module for soil static strength parameters.

[0062] The soil static strength parameter first prediction formula construction module, based on the received data and the particle mass-size fractal model of fractal theory, fits the gradation curve in the static triaxial test to obtain the fractal dimension of the preset particle size range. Then, based on the relationship between the obtained fractal dimension of the preset particle size range and the static strength parameter test value, it obtains the first prediction formula for the static strength parameter of the soil sample. Based on the formula, it obtains the first predicted value of the static strength parameter of the soil sample under different maximum stone size conditions and uploads the data to the soil sample static strength parameter first test value acquisition module.

[0063] The module for obtaining the first experimental value of the static strength parameter of the stockpile constructs a static triaxial specimen model of the stockpile soil sample based on the received data and the stress-strain relationship curve of the stockpile soil sample without considering oversized boulders. It then performs numerical simulation calibration to obtain the mesoscopic contact parameters of the numerical model. Based on the obtained mesoscopic contact parameters of the numerical model, it conducts numerical tests using the equal substitution method to obtain the first experimental value of the static strength parameter of the stockpile under different maximum boulder sizes without considering oversized boulders. The data is then uploaded to the module for constructing the second prediction formula for the static strength parameter of the soil.

[0064] The second prediction formula construction module of the soil static strength parameter constructs the second prediction formula of the soil static strength parameter considering the oversized block stone according to the received data, compares the first prediction value of the static strength parameter value of the accumulation body under the condition of different maximum block stone sizes with the first test value of the static strength parameter value of the accumulation body under the condition of different maximum block stone sizes, and judges whether the comparison passes or not, if the comparison does not pass, the granularity fractal dimension value of the non-scaling interval of the oversized block stone is introduced to modify the first prediction formula of the static strength parameter of the accumulation body soil sample, otherwise, the first prediction formula of the static strength parameter of the accumulation body soil sample is directly used to obtain the second prediction formula of the soil static strength parameter considering the oversized block stone, and the data is uploaded to the formula reliability judgment and updating module;

[0065] The formula reliability judgment and updating module obtains the second test value of the static strength parameter value of the accumulation body under the condition of different maximum block stone sizes by carrying out the static triaxial test through the large triaxial instrument according to the received data, obtains the second prediction value of the static strength parameter value of the accumulation body considering the oversized block stone based on the second prediction formula of the soil static strength parameter, compares the second prediction value with the second test value, judges the reliability of the second prediction formula of the soil static strength parameter considering the oversized block stone, if the judgment passes, the data is uploaded to the soil static strength parameter prediction module, otherwise, the second prediction formula of the soil static strength parameter considering the oversized block stone is modified and updated, and the updated data is used as the input of the formula reliability judgment and updating module to run the module again;

[0066] The soil static strength parameter prediction module completes the prediction of the soil static strength parameter considering the oversized block stone according to the received data.

[0067] The application discloses a prediction method and system for soil static strength parameters considering oversized block stones, which overcomes the problem that the traditional method is difficult to consider the influence of oversized block stones on the overall static strength of soil, and can accurately and effectively predict the static strength parameters of soil containing oversized block stones. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 It is a method flowchart of the application;

[0069] Figure 2 It is a system structure schematic diagram of the application;

[0070] Figure 3 It is a grading curve schematic diagram of the internal chamber test of the accumulation body soil sample based on the particle mass-particle size fractal model fitting of the fractal theory of the embodiment of the application;

[0071] Figure 4 It is a relationship diagram of the granularity fractal dimension value of the non-scaling interval of the fine particle and the test value of the static strength parameter of the accumulation body soil;

[0072] Figure 5is a relationship diagram of the particle size fractal dimension value of the coarse particle non-scaling interval of the embodiment of the application and the test value of the static strength parameter of the soil body of the accumulation body;

[0073] Figure 6 is a numerical model schematic diagram of the embodiment of the application under the condition of the same stone content and different maximum block stone sizes.

[0074] Figure 7 is a schematic diagram of the ratio of the numerical test value of the static strength parameter of the accumulation body to the formula predicted value varying with the stone content;

[0075] Figure 8 is a comparison schematic diagram of the corrected predicted value of the static strength parameter of the accumulation body to the numerical test value;

[0076] Figure 9 is a schematic diagram of the relationship between the corrected formula predicted value of the static strength parameter of the accumulation body soil body and the friction angle range of the accumulation body obtained by the indoor static triaxial test;

[0077] Figure 10 is a prediction interval diagram of the static strength parameter of the accumulation body of the debris flow in the embodiment of the application in the range of different maximum particle sizes and stone contents. DETAILED DESCRIPTION

[0078] The application provides a prediction method of the static strength parameter of soil considering super-diameter block stones, and a flowchart schematic diagram is shown in the figure. Figure 1 The method comprises the following steps:

[0079] S1. Perform a static triaxial test to obtain a stress-strain relationship curve of the accumulation body soil sample without considering super-diameter block stones, and then measure the static strength parameter test value under the corresponding working condition according to the obtained stress-strain relationship curve of the accumulation body soil sample without considering super-diameter block stones.

[0080] Step S1 comprises the following steps:

[0081] Perform a static triaxial test, prepare a cylindrical soil sample according to the compaction degree and other conditions required by the test, and then wrap the rubber film and place it in the pressure chamber;

[0082] Put the sample into the static triaxial instrument, ensure that the bottom and top water-permeable stones are connected with the drainage system, and seal the pressure chamber;

[0083] Adjust the pressure of the pressure chamber to apply a preset confining pressure to simulate the in-situ stress condition;

[0084] Drainage consolidation is performed on the sample, and the volume deformation of the sample is recorded until it is stable;

[0085] Apply axial stress to the sample at a constant rate, and synchronously collect the axial stress and strain of the sample through the sensor to obtain the stress-strain relationship curve of the accumulation body soil sample without considering super-diameter block stones;

[0086] According to the obtained stress-strain relationship curve of the soil sample of the accumulation body not considering the super-diameter block stone, the test values of the static strength parameters under different confining pressures and different stone contents are determined; the test values of the static strength parameters are the internal friction angles of the accumulation body; the confining pressure is a constant pressure preset in the test process; and the stone content is a percentage of the soil sample with a particle size greater than 2 mm in the total test sample.

[0087] Preferably, the confining pressures used are 100 Kpa, 150 Kpa and 200 Kpa respectively; and the stone contents used are 25%, 45% and 65% respectively.

[0088] S2. A particle mass-particle size fractal model based on fractal theory is used to fit the grading curve in the static triaxial test in step S1 to obtain the fractal dimension of a preset particle size interval, and then a first prediction formula of the static strength parameters of the accumulation body soil sample is obtained according to the relationship between the fractal dimension of the preset particle size interval and the test values of the static strength parameters obtained in step S1, and a first predicted value of the static strength parameters of the accumulation body under different maximum block stone sizes is obtained based on the formula.

[0089] Step S2 specifically includes the following steps:

[0090] A particle mass-particle size fractal model based on fractal theory is used to fit the grading curve of the accumulation body in the static triaxial test in step S1 to obtain the fractal dimension of a preset particle size interval; as shown in Figure 3 Figure 3 The grading curve of the accumulation body soil sample in the chamber test fitted by the particle mass-particle size fractal model based on fractal theory; the particle size of the fine particles is less than 2 mm; and the particle size range of the coarse particles is 2 mm-20 mm;

[0091] Then, a first prediction formula of the static strength parameters of the accumulation body soil sample is obtained according to the relationship between the fractal dimension of the preset particle size interval and the test values of the static strength parameters obtained in step S1.

[0092] A first predicted value of the static strength parameters of the accumulation body under different maximum block stone sizes is obtained based on the formula.

[0093] The particle mass-particle size fractal model based on fractal theory is expressed by the following formula:

[0094]

[0095] Wherein, R is a preset particle diameter; is the mass of the particles with a particle diameter r less than the preset particle diameter R; and M is the total mass of the particles. is the maximum particle size; and D is the fractal dimension.

[0096] ​The gradation curve is a cumulative percentage relationship of each particle size of the sample in the static triaxial test.

[0097] The first prediction formula of the static strength parameter of the heap body soil sample is obtained according to the relationship between the fractal dimension of the obtained preset particle size interval and the test value of the static strength parameter obtained in step S1, and is expressed by the following formula:

[0098]

[0099] wherein, is the internal friction angle of the heap body; is the particle fractal dimension value of the fine particle non-scaling interval; is the particle size fractal dimension value of the coarse particle non-scaling interval; is the functional relationship between the particle fractal dimension value of the fine particle non-scaling interval and the test value of the static strength parameter of the heap body soil sample; is the functional relationship between the particle size fractal dimension value of the coarse particle non-scaling interval and the test value of the static strength parameter of the heap body soil sample; and The test value of the static strength parameter of the heap body soil sample obtained by the static triaxial test in step S1 is fitted with the fractal dimension of the preset particle size interval obtained in step S2.

[0100] As an example, Figure 4 is a graph of the relationship between the particle size fractal dimension value of the fine particle non-scaling interval and the test value of the static strength parameter of the heap body soil sample, Figure 5 is a graph of the relationship between the particle size fractal dimension value of the coarse particle non-scaling interval and the test value of the static strength parameter of the heap body soil sample. As Figure 4 , Figure 5 shown, both relationships are linear, thereby obtaining the first prediction formula of the static strength parameter of the heap body soil sample, which is expressed by the following formula:

[0101]

[0102] wherein, is the internal friction angle of the heap body; is the particle fractal dimension value of the fine particle non-scaling interval; is the particle size fractal dimension value of the coarse particle non-scaling interval; is the first constant fitted; is the second constant fitted; is the third constant fitted;

[0103] Further, the relationship between the fractal dimension of each particle size interval and the test value of the static strength parameter of the heap body soil sample may be different from the above example, and may also present a nonlinear relationship, for example, when both present a parabolic relationship, the first prediction formula of the static strength parameter of the heap body soil sample is obtained, which is expressed by the following formula:

[0104]

[0105] wherein, is the internal friction angle of the heap; is the particle fractal dimension value of the fine particle non-scaling interval; is the particle size fractal dimension value of the coarse particle non-scaling interval; is the fourth constant obtained by fitting; is the fifth constant obtained by fitting; is the sixth constant obtained by fitting; is the seventh constant obtained by fitting; is the eighth constant obtained by fitting;

[0106] Other nonlinear relationships can be similarly extended.

[0107] S3. Based on the stress-strain relationship curve of the heap soil sample obtained in step S1 without considering oversized block stones, a static triaxial specimen model of the heap soil sample is constructed, Figure 6 is a numerical model schematic diagram under different maximum block stone sizes; the static triaxial specimen model of the heap soil sample is used for numerical simulation calibration to obtain the numerical model micro contact parameters; according to the obtained numerical model micro contact parameters, the equivalent replacement method is used for numerical test to obtain the numerical first test value of the static strength parameters of the heap under different maximum block stone sizes without considering oversized block stones;

[0108] Step S3 includes the following steps:

[0109] In the numerical simulation software, a static triaxial specimen model of the heap soil sample is constructed;

[0110] Based on the stress-strain relationship curve in step S1, numerical simulation calibration is carried out to obtain the micro contact parameters of the model;

[0111] According to the micro contact parameters, the equivalent replacement method is used to change the maximum size of the block stone in the specimen while keeping the block stone content unchanged in the specimen model, and numerical test is carried out to obtain the numerical first test value of the static strength parameters of the heap under different maximum block stone sizes.

[0112] The micro contact parameters include effective modulus, stiffness ratio, friction coefficient, and anti-rotation friction coefficient.

[0113] S4. Based on the first predicted value of the static strength parameter of the heap body under the condition of different maximum block stone sizes obtained in step S2, the first predicted value is compared with the first test value of the static strength parameter of the heap body under the condition of different maximum block stone sizes obtained in step S3, and a judgment is made. If the judgment fails, the particle size fractal dimension value of the super-diameter block stone non-scaling interval is introduced to modify the first predicted formula of the static strength parameter of the heap body soil sample obtained in step S2, otherwise the first predicted formula of the static strength parameter of the heap body soil sample is directly used to obtain the second predicted formula of the static strength parameter of the soil body considering the super-diameter block stone;

[0114] Step S4 includes the following steps:

[0115] The first error changes with the stone content relationship is obtained by comparing the first predicted value of the static strength parameter of the heap body with the first test value of the static strength parameter of the heap body under the condition of different maximum block stone sizes; the first error changes with the stone content relationship includes linear form and nonlinear form; the first error is the difference between the first test value of the static strength parameter of the heap body and the first predicted value of the static strength parameter of the heap body; if the error between the first predicted value of the static strength parameter of the heap body and the first test value of the static strength parameter of the heap body is less than or equal to 10%, the first predicted formula of the static strength parameter of the heap body soil sample is directly used as the second predicted formula of the static strength parameter of the soil body considering the super-diameter block stone, otherwise the following steps are performed:

[0116] The heap body soil is divided into three parts: fine particles, coarse particles and super-diameter block stones; the particle size of the fine particles is less than 2mm; the particle size of the coarse particles is in the range of 2mm-20mm; the particle size of the super-diameter block stone is greater than 20mm;

[0117] According to the particle mass-particle size fractal model of the fractal theory, the grading curve of the part of the heap body soil is fitted to obtain the particle size fractal dimension value of the super-diameter block stone non-scaling interval;

[0118] According to the first error changes with the stone content relationship, the first predicted formula of the static strength parameter of the heap body soil sample is modified based on the particle size fractal dimension value of the super-diameter block stone non-scaling interval to obtain the second predicted formula of the static strength parameter of the soil body considering the super-diameter block stone, which is expressed by the following formula:

[0119]

[0120] Wherein, is the internal friction angle of the heap body; is the particle fractal dimension value of the fine particle non-scaling interval; is the modified particle size fractal dimension value of the coarse particle non-scaling interval; is the functional relationship between the particle fractal dimension value of the fine particle non-scaling interval and the test value of the static strength parameter of the heap body soil; The function relationship between the particle size fractal dimension value of the modified coarse particle non-scale interval and the test value of the static strength parameter of the soil body is obtained.

[0121] Under the premise of ensuring the unchanged content of the block stone in the sample, the maximum size of the block stone in the sample is changed by using the equivalent replacement method. When only the maximum particle size of the block stone is changed, the particle size fractal dimension value of the fine particle non-scale interval of the soil body of the accumulation body remains unchanged, and the particle size fractal dimension value of the coarse particle non-scale interval changes. Therefore, the particle size fractal dimension value of the oversized block stone non-scale interval is introduced, and the particle size fractal dimension value of the coarse particle non-scale interval in the first prediction formula of the static strength parameter of the soil sample of the accumulation body is corrected. Specifically, the particle size fractal dimension value of the coarse particle non-scale interval is corrected.

[0122] According to the relationship between the first error and the stone content, the correction function of the particle size fractal dimension value of the coarse particle non-scale interval is obtained, and the particle size fractal dimension value of the oversized block stone non-scale interval is taken as the independent variable.

[0123] According to the correction function of the particle size fractal dimension value of the coarse particle non-scale interval, the particle size fractal dimension value of the coarse particle non-scale interval in the first prediction formula of the static strength parameter of the soil sample of the accumulation body is corrected, and the following formula is used to represent:

[0124]

[0125] wherein, is the particle size fractal dimension value of the corrected coarse particle non-scale interval; is the particle size fractal dimension value of the coarse particle non-scale interval; is the particle size fractal dimension value of the oversized block stone non-scale interval; is the correction function of the particle size fractal dimension value of the coarse particle non-scale interval; obtained through the variation law of the first error with the stone content, including a linear form and a nonlinear form;

[0126] Finally, the second prediction formula of the static strength parameter of the soil body considering the oversized block stone is obtained.

[0127] In an example, Figure 7 is a schematic diagram of the variation law of the ratio of the formula prediction value to the numerical test value with the stone content. Figure 8 is a schematic diagram of the comparison between the corrected prediction value of the static strength parameter of the accumulation body and the numerical test value. According to the relationship between the two, the second prediction formula of the static strength parameter of the soil body considering the oversized block stone is as follows:

[0128]

[0129] wherein, is the internal friction angle of the accumulation body; is the particle size fractal dimension value of the fine particle non-scale interval; is the particle size fractal dimension value of the corrected coarse particle non-scale interval; when is a first constant obtained by fitting; ; is a first constant obtained by fitting; is a second constant obtained by fitting; is a third constant obtained by fitting; is a ninth constant obtained by fitting; is a tenth constant obtained by fitting; is an eleventh constant obtained by fitting; when is a twelfth constant obtained by fitting; ; ; is a thirteenth constant obtained by fitting; is a thirteenth constant obtained by fitting;

[0130] S5. Obtain a second test value of the static strength parameter of the accumulation body under different maximum block stone sizes by a large-scale static triaxial test under the condition of considering the super-diameter block stone; compare the second predicted value of the static strength parameter of the accumulation body obtained based on the second prediction formula of the static strength parameter of the soil body with the second test value of the static strength parameter of the accumulation body, to judge the reliability of the second prediction formula of the static strength parameter of the soil body considering the super-diameter block stone, if the judgment is passed, go to the next step, otherwise, update the second prediction formula of the static strength parameter of the soil body considering the super-diameter block stone, and repeat step S5;

[0131] Step S5 is specifically:

[0132] Obtain a second test value of the static strength parameter of the accumulation body under different maximum block stone sizes by a large-scale static triaxial test under the condition of considering the super-diameter block stone;

[0133] Preferably, the large-scale triaxial apparatus adopts a large-scale triaxial apparatus capable of bearing a cylindrical sample with a size of 300mmx600mm;

[0134] Obtain a second predicted value of the static strength parameter of the accumulation body considering the super-diameter block stone based on the second prediction formula of the static strength parameter of the soil body;

[0135] Compare the second predicted value of the static strength parameter of the accumulation body considering the super-diameter block stone with the second test value of the static strength parameter of the accumulation body, to obtain a second error change relationship with the stone content; if the error between the second predicted value of the static strength parameter of the accumulation body considering the super-diameter block stone and the second test value of the static strength parameter of the accumulation body is less than or equal to 10%, go to the next step, otherwise, update the second prediction formula of the static strength parameter of the soil body considering the super-diameter block stone, and repeat step S5; the second error change relationship includes a linear form and a nonlinear form;

[0136] The second prediction formula of the current soil static strength parameter considering the super-diameter block stone is modified and updated, and specifically:

[0137] The accumulated soil is divided into three parts, namely fine particles, coarse particles and super-diameter block stones;

[0138] According to the particle size fractal model of the fractal theory, the grading curve of the part of the accumulated soil is fitted, and the particle size fractal value of the non-scaling interval of the super-diameter block stone is obtained;

[0139] According to the second error change relationship with the stone content, the parameter in the second prediction formula of the static strength parameter of the accumulated soil sample is modified based on the particle size fractal value of the non-scaling interval of the super-diameter block stone, as a new second prediction formula of the static strength parameter of the accumulated soil sample.

[0140] Examples, Figure 9 The relationship between the prediction value of the modified formula of the static strength parameter of the accumulated soil and the range of the friction angle of the accumulated soil measured by the indoor static triaxial is shown in the schematic diagram.

[0141] S6. According to the second prediction formula of the soil static strength parameter considering the super-diameter block stone obtained in step S4, the prediction of the soil static strength parameter considering the super-diameter block stone is completed.

[0142] Step S6 specifically includes the following steps: obtaining the fine particle non-scaling interval particle size fractal value, the coarse particle non-scaling interval particle size fractal value and the super-diameter block stone non-scaling interval particle size fractal value of the super-diameter block stone soil to be predicted;

[0143] According to the second prediction formula of the static strength parameter of the accumulated soil sample finally obtained in step S5, the static strength parameter prediction of the super-diameter block stone soil to be predicted is carried out, and the prediction value of the static strength parameter of the super-diameter block stone soil to be predicted is obtained.

[0144] The application also provides a system for realizing the prediction method of the soil static strength parameter considering the super-diameter block stone, and a structure schematic diagram thereof is shown in Figure 2 The system comprises a data acquisition module, a soil static strength parameter first prediction formula construction module, an accumulated soil static strength parameter value first test value acquisition module, a soil static strength parameter second prediction formula construction module, a formula reliability judgment and update module, and a soil static strength parameter prediction module.

[0145] The data acquisition module obtains the stress-strain relationship curve of the accumulated soil sample without considering the super-diameter block stone through the static triaxial test, and then determines the static strength parameter test value under the corresponding working condition according to the obtained stress-strain relationship curve of the accumulated soil sample without considering the super-diameter block stone, and uploads the data to the soil static strength parameter first prediction formula construction module;

[0146] The soil static strength parameter first prediction formula construction module, according to the received data, based on the particle mass-particle size fractal model of fractal theory, fits the grading curve in the static triaxial test, obtains the fractal dimension of the preset particle size interval, and then according to the relationship between the obtained fractal dimension of the preset particle size interval and the static strength parameter test value, obtains the first prediction formula of the static strength parameter of the accumulated soil sample, and based on the formula, obtains the first prediction value of the static strength parameter value of the accumulated soil under the condition of different maximum block stone sizes, and uploads the data to the accumulated soil static strength parameter value first test value acquisition module;

[0147] The accumulated soil static strength parameter value first test value acquisition module, according to the received data, based on the stress-strain relationship curve of the accumulated soil sample without considering the oversized block stone, constructs a static triaxial test sample model of the accumulated soil sample, carries out numerical simulation calibration, and obtains the micro contact parameters of the numerical model; according to the obtained micro contact parameters of the numerical model, the numerical test is carried out by using the equivalent replacement method, and the first test value of the static strength parameter value of the accumulated soil under the condition of different maximum block stone sizes without considering the oversized block stone is obtained, and the data is uploaded to the soil static strength parameter second prediction formula construction module;

[0148] The soil static strength parameter second prediction formula construction module, according to the received data, based on the first prediction value of the static strength parameter of the accumulated soil under the condition of different maximum block stone sizes, compares it with the first test value of the static strength parameter of the accumulated soil under the condition of different maximum block stone sizes, and if the judgment fails, the particle size fractal dimension value of the non-scaling interval of the oversized block stone is introduced to modify the first prediction formula of the static strength parameter of the accumulated soil sample, otherwise the first prediction formula of the static strength parameter of the accumulated soil sample is directly used, to obtain the second prediction formula of the static strength parameter of the accumulated soil considering the oversized block stone, and the data is uploaded to the formula reliability judgment and updating module;

[0149] The formula reliability judgment and updating module, according to the received data, carries out static triaxial test through a large triaxial instrument, and obtains the second test value of the static strength parameter of the accumulated soil under the condition of different maximum block stone sizes considering the oversized block stone; based on the second prediction value of the static strength parameter of the accumulated soil considering the oversized block stone obtained by the soil static strength parameter second prediction formula, the second prediction value is compared with the second test value of the static strength parameter of the accumulated soil, and the reliability of the current soil static strength parameter second prediction formula considering the oversized block stone is judged, if the judgment is passed, the data is uploaded to the soil static strength parameter prediction module, otherwise the current soil static strength parameter second prediction formula considering the oversized block stone is modified and updated, and the updated data is used as the input of the formula reliability judgment and updating module to run the module again;

[0150] The soil static strength parameter prediction module, according to the received data, completes the prediction of the soil static strength parameter considering the oversized block stone.

[0151] The method of the present application is further described below in connection with one embodiment:

[0152] Firstly, static triaxial tests are carried out to obtain the test values of the static strength parameters of the accumulation body soil sample without considering the super-diameter block stone, and the specific data are shown in Table 1.

[0153] Table 1 Static strength parameter table of accumulation body

[0154]

[0155] According to the particle mass-particle size fractal model of the fractal theory, the fractal dimensions of each particle size interval are fitted by fitting the grading curve of the accumulation body sand and gravel part of the static triaxial sample, and the fractal dimensions of each particle size interval are used to represent the grading information of the accumulation body soil sample, and the specific data are shown in Table 2.

[0156] Table 2 Fractal dimension value summary table under the double fractal structure model of the debris flow accumulation body

[0157]

[0158] According to the relationship between the fractal dimensions of each particle size interval and the test values of the static strength parameters of the accumulation body soil, the establishment method of the prediction formula of the static strength parameters of the accumulation body soil sample can be determined, and the fitting formula is shown as follows.

[0159]

[0160] In the formula: is the internal friction angle of the debris flow accumulation body; is the particle size fractal dimension value of the fine particle non-scaling interval; is the particle size fractal dimension value of the coarse particle non-scaling interval.

[0161] In the numerical simulation software, the static triaxial sample model of the accumulation body soil sample is constructed, the fine contact parameters of the numerical model are obtained by numerical simulation calibration based on the stress-strain relationship curve obtained in the laboratory test, and the specific data are shown in Table 3.

[0162] Table 3 Contact parameter summary table

[0163]

[0164] The numerical test is carried out by using the equivalent replacement method to change the maximum size of the block stone in the sample while keeping the block stone content in the sample unchanged, the numerical test values of the static strength parameters of the accumulation body under different maximum block stone sizes are obtained, and the static strength parameters of the accumulation body with the same maximum block stone size as the numerical test are obtained according to the prediction formula of the static strength parameters of the accumulation body soil sample.

[0165] The error development law of the formula prediction value and the numerical test value with the change of the stone content is obtained by comparing the formula prediction value with the numerical test value; the particle size fractal dimension value of the coarse particle non-scaling interval in the formula is corrected by introducing the particle size fractal dimension value of the oversized block stone non-scaling interval based on the particle mass-particle size fractal model of the fractal theory, and the soil static strength parameter prediction formula considering the oversized block stone is obtained:

[0166]

[0167] In the formula: is the internal friction angle of the debris flow accumulation body; is the particle size fractal dimension value of the fine particle non-scaling interval; is the particle size fractal dimension value of the coarse particle non-scaling interval; is the particle size fractal dimension value of the oversized block stone non-scaling interval.

[0168] The static strength parameter test value of the accumulation body soil sample considering the oversized block stone is obtained through the large-scale static triaxial test; the reliability of the soil static strength parameter prediction formula considering the oversized block stone is determined by comparing the formula prediction value of the soil static strength parameter prediction formula considering the oversized block stone with the static strength parameter test value of the accumulation body soil sample considering the oversized block stone;

[0169] The soil static strength parameter prediction value considering the oversized block stone is obtained according to the soil static strength parameter prediction formula considering the oversized block stone. Figure 10 The prediction interval of the static strength parameter of the debris flow accumulation body is given with the maximum particle size from 20 mm to 200 mm and the stone content from 25% to 65%.

[0170] The above is the preferred embodiment of the present application, and it should be pointed out that the ordinary skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements are also considered as the protection scope of the present application.

Claims

1. A method for predicting the static strength parameters of soil considering oversized boulders, characterized in that, Includes the following steps: S1. Obtain the stress-strain relationship curve of the soil sample of the accumulator without considering oversized boulders through static triaxial test, and then determine the test value of the static strength parameter under the corresponding working condition based on the stress-strain relationship curve. S2. Based on the particle mass-size fractal model of fractal theory, obtain the fractal dimension of the preset particle size range. Then, according to the relationship between the fractal dimension of the preset particle size range and the static strength parameter test value obtained in step S1, obtain the first prediction formula of the static strength parameter of the soil sample of the accumulation body. Based on the first prediction formula, obtain the first prediction value of the static strength parameter of the accumulation body under different maximum stone size conditions. S3. Based on the stress-strain relationship curve obtained in step S1, perform numerical simulation calibration to obtain the microscopic contact parameters of the numerical model; based on the microscopic contact parameters, conduct numerical experiments to obtain the first experimental value of the static strength parameter of the aggregate. S4. Compare the first predicted value obtained in step S2 with the first experimental value obtained in step S3 to make a judgment. If the judgment fails, the first prediction formula obtained in step S2 is corrected. Otherwise, the first prediction formula is directly adopted to obtain the second prediction formula for the static strength parameter of soil considering oversized boulders. S5. Obtain the second experimental value of the static strength parameter of the pile considering oversized boulders through a large static triaxial test; obtain the second predicted value of the static strength parameter of the pile considering oversized boulders based on the second prediction formula, compare it with the second experimental value, and if the judgment is successful, proceed to the next step; otherwise, revise and update the current second prediction formula and repeat step S5. S6. Based on the second prediction formula obtained in step S5, complete the prediction of the static strength parameters of the soil considering oversized boulders; Step S2 specifically includes the following steps: Based on the fractal theory, a particle mass-size fractal model is used to fit the gradation curves of the fine and coarse particles in the static triaxial test in step S1, and obtain the fractal dimension of the preset particle size range. Then, based on the relationship between the fractal dimension of the preset particle size range and the test value of the static strength parameter obtained in step S1, the first prediction formula for the static strength parameter of the accumulated soil sample is obtained. The first predicted value of the static strength parameter of the accumulation body under different maximum stone block sizes is obtained based on the formula; The particle mass-size fractal model based on fractal theory is expressed by the following formula: Where R is the preset particle diameter; M represents the mass of particles with a diameter r smaller than the preset particle diameter R; M represents the total mass of particles. Where D is the maximum particle size; and D is the fractal dimension. Based on the relationship between the fractal dimension of the obtained preset particle size range and the experimental value of the static strength parameter obtained in step S1, the first prediction formula for the static strength parameter of the accumulated soil sample is obtained, expressed by the following formula: in, The internal friction angle of the accumulation body; For the scale-free region of fine particles, the particle fractal dimension is given. This represents the particle size fractal dimension of the scale-free region for coarse particles; This represents the functional relationship between the particle fractal dimension of the scale-free region of fine particles and the experimental values ​​of the static strength parameters of the soil in the accumulated mass. This represents the functional relationship between the fractal dimension of coarse-grained scale-free regions and the experimental values ​​of static strength parameters of the accumulated soil. and The static strength parameters of the soil mass obtained from the static triaxial test in step S1 are obtained by fitting the fractal dimension of the preset particle size range obtained in step S2. Step S3 includes the following steps: In numerical simulation software, a static triaxial specimen model of the soil accumulation is constructed. Based on the stress-strain relationship curve described in step S1, numerical simulation calibration is performed to obtain the microscopic contact parameters of the model; the microscopic contact parameters include effective modulus, stiffness ratio, friction coefficient, and anti-rotation friction coefficient. Based on the microscopic contact parameters, while ensuring that the content of boulders in the sample model remains constant, the maximum size of the boulders in the sample is changed by the equal replacement method. Numerical tests are carried out to obtain the first experimental value of the static strength parameter of the accumulation body under different maximum boulder sizes. Step S4 includes the following steps: By comparing the first predicted value and the first experimental value of the static strength parameter of the stockpile under different maximum stone block sizes, the relationship between the first error and the stone content is obtained. This relationship includes both linear and nonlinear forms. The first error is the difference between the first experimental value and the first predicted value of the static strength parameter of the stockpile. If the error between the first predicted value and the first experimental value is less than or equal to 10%, the first prediction formula for the static strength parameter of the stockpile soil sample is directly used as the second prediction formula for the static strength parameter of the soil considering oversized stones; otherwise, the following steps are performed: The soil mass of the accumulator is divided into three parts: fine-grained, coarse-grained, and oversized boulders. Based on the particle mass-size fractal model of the fractal theory, the gradation curves of the three parts of the accumulated soil, namely fine particles, coarse particles and oversized boulders, are fitted to obtain the particle size fractal dimension of the scale-free region of oversized boulders. Based on the relationship between the first error and the stone content, the first prediction formula for the static strength parameter of the soil sample in the accumulator is modified based on the particle size fractal dimension of the scale-free interval of oversized stones, resulting in the second prediction formula for the static strength parameter of the soil considering oversized stones, expressed by the following formula: in, The internal friction angle of the accumulation body; For the scale-free region of fine particles, the particle fractal dimension is given. This represents the particle size fractal dimension of the scale-free region for coarse particles after correction. This represents the functional relationship between the particle fractal dimension of the scale-free region of fine particles and the experimental values ​​of the static strength parameters of the soil in the accumulated mass. This represents the functional relationship between the particle size fractal dimension of the scale-free range for coarse particles and the experimental values ​​of the static strength parameters of the soil in the accumulated mass. The particle size fractal dimension of the scale-free interval of oversized boulders is introduced to correct the particle size fractal dimension of the coarse-grained scale-free interval in the first prediction formula for the static strength parameter of the accumulated soil sample. Specifically: Based on the relationship between the first error and the stone content, a correction function for the particle size fractal dimension of the scale-free interval of coarse particles is obtained, wherein the correction function takes the particle size fractal dimension of the scale-free interval of oversized stones as the independent variable. Based on the correction function for the fractal dimension of coarse-grained scale-free interval, the fractal dimension of coarse-grained scale-free interval in the first prediction formula for the static strength parameter of the accumulated soil sample is corrected, and expressed by the following formula: in, This represents the particle size fractal dimension of the scale-free region for coarse particles after correction. This represents the particle size fractal dimension of the scale-free region for coarse particles; The fractal dimension of the particle size in the scale-free range of oversized stones; This is a correction function for the fractal dimension of coarse-grained scale-free intervals; The first error is obtained by the variation law of stone content, including linear and nonlinear forms; Finally, the second prediction formula for the static strength parameters of soil considering oversized boulders is obtained; Through large-scale static triaxial tests, the second experimental values ​​of the static strength parameters of the embankment under different maximum block sizes were obtained, taking into account oversized blocks. The second prediction value of the static strength parameter of the soil is obtained based on the second prediction formula of the static strength parameter of the pile considering oversized boulders. The second predicted value of the static strength parameter of the pile considering oversized boulders is compared with the second experimental value of the static strength parameter of the pile to obtain the relationship between the second error and the stone content. If the error between the second predicted value of the static strength parameter of the pile considering oversized boulders and the second experimental value of the static strength parameter of the pile is less than or equal to 10%, proceed to the next step; otherwise, the current second prediction formula of the static strength parameter of the soil considering oversized boulders is revised and updated, and step S5 is repeated. The relationship between the second error and the stone content includes linear and nonlinear forms. The second prediction formula for soil static strength parameters considering oversized boulders is revised and updated as follows: The soil mass of the accumulator is divided into three parts: fine-grained, coarse-grained, and oversized boulders. Based on the particle mass-size fractal model of the fractal theory, the gradation curves of the three parts of the accumulated soil, namely fine particles, coarse particles and oversized boulders, are fitted to obtain the particle size fractal dimension of the scale-free region of oversized boulders. Based on the relationship between the second error and the stone content, the parameters in the second prediction formula for the static strength parameters of the soil sample of the accumulation body are corrected based on the particle size fractal dimension of the scale-free interval of the oversized stones, and this is used as the new second prediction formula for the static strength parameters of the soil sample of the accumulation body.

2. The method for predicting the static strength parameters of soil considering oversized boulders according to claim 1, characterized in that, Step S6 specifically includes the following steps: obtaining the scale-free fractal dimension of fine particles, the scale-free fractal dimension of coarse particles, and the scale-free fractal dimension of oversized boulders in the soil mass containing the embankment to be predicted; Based on the second prediction formula for the static strength parameter of the soil sample obtained in step S5, the static strength parameter of the soil containing oversized stones is predicted, and the predicted value of the static strength parameter of the soil sample containing oversized stones is obtained.

3. A system for implementing the method for predicting the static strength parameters of soil considering oversized boulders as described in any one of claims 1 to 2, characterized in that, It includes a data acquisition module, a first prediction formula construction module for soil static strength parameters, a first test value acquisition module for the static strength parameters of the stockpile, a second prediction formula construction module for soil static strength parameters, a formula reliability judgment and update module, and a soil static strength parameter prediction module. The data acquisition module obtains the stress-strain relationship curve of the soil sample without considering oversized boulders through static triaxial test. Then, based on the obtained stress-strain relationship curve of the soil sample without considering oversized boulders, it determines the test value of the static strength parameter under the corresponding working condition and uploads the data to the first prediction formula construction module for soil static strength parameter. The soil static strength parameter first prediction formula construction module, based on the received data and the particle mass-size fractal model of fractal theory, fits the gradation curve in the static triaxial test to obtain the fractal dimension of the preset particle size range. Then, based on the relationship between the obtained fractal dimension of the preset particle size range and the static strength parameter test value, it obtains the first prediction formula for the static strength parameter of the soil sample. Based on the formula, it obtains the first predicted value of the static strength parameter of the soil sample under different maximum stone size conditions and uploads the data to the soil sample static strength parameter first test value acquisition module. The module for obtaining the first experimental value of the static strength parameter of the stockpile constructs a static triaxial specimen model of the stockpile soil sample based on the received data and the stress-strain relationship curve of the stockpile soil sample without considering oversized boulders. It then performs numerical simulation calibration to obtain the mesoscopic contact parameters of the numerical model. Based on the obtained mesoscopic contact parameters of the numerical model, it conducts numerical tests using the equal substitution method to obtain the first experimental value of the static strength parameter of the stockpile under different maximum boulder sizes without considering oversized boulders. The data is then uploaded to the module for constructing the second prediction formula for the static strength parameter of the soil. The second prediction formula construction module for soil static strength parameters is based on the received data. It compares the first predicted value of the static strength parameter of the pile under different maximum stone size conditions with the first experimental value of the static strength parameter of the pile under different maximum stone size conditions. If the judgment fails, the particle size fractal dimension of the scale-free interval of the oversized stone is introduced to correct the first prediction formula for the static strength parameter of the pile soil sample. Otherwise, the first prediction formula for the static strength parameter of the pile soil sample is directly adopted to obtain the second prediction formula for the static strength parameter of the soil considering the oversized stone, and the data is uploaded to the formula reliability judgment and update module. The formula reliability judgment and update module, based on the received data, obtains the second test values ​​of the static strength parameters of the stockpile under different maximum block sizes, considering oversized boulders, through a large-scale static triaxial test. Based on the second prediction formula for the static strength parameters of the soil, it obtains the second predicted value of the static strength parameters of the stockpile considering oversized boulders, compares it with the second test value of the static strength parameters of the stockpile, and performs a reliability judgment on the current second prediction formula for the static strength parameters of the soil considering oversized boulders. If the judgment is successful, the data is uploaded to the static strength parameter prediction module; otherwise, the current second prediction formula for the static strength parameters of the soil considering oversized boulders is corrected and updated, and the updated data is used as input to the formula reliability judgment and update module to run this module again. Based on the received data, the soil static strength parameter prediction module completes the prediction of the soil static strength parameters taking into account oversized boulders.

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