A method for determining the width and macroscopic strength of the transition zone of the grouting reinforcement interface

Abstract

The present invention discloses a method for determining the width and macroscopic strength of a grouting reinforcement interface transition zone. The method comprises six steps: sample preparation, macroscopic mechanical parameter testing, microscopic nanoindentation testing, determination of the width of the grouting reinforcement interface transition zone, determination of the microscopic parameters of the grouting reinforcement interface transition zone, and determination of the macroscopic strength of the grouting reinforcement interface transition zone. Compared with the prior art, the method for determining the width and macroscopic strength of a grouting reinforcement interface transition zone prepared by the present invention studies the mechanical parameters of the interface transition zone of a slurry-coal cement body, accurately determining the boundary of the interface transition zone and the macroscopic strength of the interface transition zone, and thus achieving uniform standardization and quantification of the test results of the interface transition zone, thereby better studying and understanding the mechanical properties and behavior of the slurry-coal binary.

Description

Technical Field

[0001] The invention relates to the technical field of underground engineering grouting materials and numerical simulation, and in particular to a method for determining the width and macroscopic strength of a grouting reinforcement interface transition zone. Background Art

[0002] Grouting is one of the main methods for controlling deep tunnels. In addition to the slurry's own strength, slurry permeability and cementing effect, which play a significant role in the stability of the tunnel, the slurry can also fill the broken coal blocks in the small coal pillars, improve the uniaxial compressive strength of the coal rock and the coal rock's ability to resist shear deformation and failure. There is an interface transition zone (ITZ) at the slurry-coal interface, and the existence of the interface transition zone will affect the overall strength of the specimen. Regarding the factors affecting the interface transition, existing work has deeply studied the influence of aggregate type and particle size on the interface transition zone. However, there is little research on the ITZ region of the broken coal slurry assembly and its influence, and it is difficult to determine the mechanical parameters of the interface in the interface transition zone.

[0003] Existing methods for measuring the interfacial transition zone (IZ) rely on various microscopy techniques to observe the morphology of the IZ and determine its width by processing the grayscale of the image. However, in reality, the IZ and the cementitious material in the slurry are difficult to directly identify. The size and morphology of the IZ are related to the shape and surface characteristics of the aggregate. Different aggregates may result in different IZs, resulting in heterogeneous and non-uniform IZ test results, making them difficult to standardize and quantify.

[0004] Therefore, how to provide a method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone so that it can achieve the technical effect of accurately determining the width of the interface transition zone and its macroscopic mechanical parameters is a technical problem that technical personnel in this field urgently need to solve. Summary of the Invention

[0005] In view of the problems existing in the prior art, the technical problem to be solved by the present invention is to provide a method for determining the width and macroscopic strength of the interface transition zone of grouting reinforcement, to determine the accuracy of its interface transition zone width and its macroscopic mechanical parameters, so as to better study and understand the mechanical properties and behavior of the slurry-coal binary.

[0006] To achieve the above-mentioned purpose, the present invention provides a method for determining the width and macroscopic strength of the transition zone of the grouting reinforcement interface, and the determination method specifically includes: S1, sample preparation: collecting raw coal samples, screening the raw coal samples, and respectively preparing slurry standard samples, slurry-coal cement, slurry-coal binary interface slices and raw coal block standard samples; S2, macroscopic mechanical parameter test: carrying out uniaxial compression test on the slurry standard sample, slurry-coal cement and raw coal block standard sample prepared by S1 to test the macroscopic mechanical parameters; S3, microscopic nanoindentation test: carrying out nanoindentation test on the slurry-coal binary interface slice prepared by S1 to obtain the microscopic mechanical parameters of the slurry-coal binary interface slice; S4, determination of the width of the transition zone of the grouting reinforcement interface: through S3 test The micromechanical parameters of the slurry-coal binary interface thin slice are obtained, and the indentation modulus cloud map of the slurry-coal binary interface thin slice test area is drawn, and the width of the interface transition zone is determined by dividing the measuring line; S5, microparameters of the grouting reinforcement interface transition zone: the area proportion of each area and the average indentation modulus of each area are determined by the indentation modulus cloud map of the slurry-coal binary interface thin slice test area drawn by S4, and the average indentation modulus of the slurry-coal binary interface thin slice test area is obtained by weighted calculation of the area proportion; S6, macroscopic strength of the grouting reinforcement interface transition zone: the fitting relationship between the macroscopic mechanical parameters obtained by S2 and the average indentation modulus of the slurry-coal binary interface thin slice test area obtained by S5 is obtained, and the macroscopic strength of the grouting interface transition zone is determined according to the fitting relationship.

[0007] In the first aspect, the preparation of the slurry standard sample specifically includes: pouring the slurry to obtain a standard cylindrical sample, and curing the poured standard cylindrical sample for 28 days in an environment with a temperature of 20°C to 25°C and a humidity greater than 95% to obtain a slurry standard sample.

[0008] In the first aspect, the preparation of slurry-coal cement specifically includes: selecting broken coal blocks from the screened raw coal sample, pouring slurry on the selected broken coal blocks to obtain a slurry-coal cement test block, wherein the slurry-coal cement test block is a cube with a size of 150mm×150mm×150mm; curing the cast slurry-coal cement test block in an environment with a temperature of 20℃~25℃ and a humidity greater than 95% for 28 days, and then drilling a slurry-coal cement standard sample from the slurry-coal cement test block by means of coring, wherein the slurry-coal cement standard sample is a cylindrical sample with a diameter of 50mm and a height of 100mm.

[0009] In the first aspect, the preparation of the slurry-coal binary interface slice specifically includes: cutting the prepared slurry-coal cement standard sample along the radial direction, and fine-grinding and polishing the cut sample surface to obtain a slurry-coal binary interface slice, wherein the diameter of the slurry-coal binary interface slice is 50 mm and the height is 25 mm.

[0010] In the first aspect, the preparation of the raw coal block standard sample specifically includes: linearly cutting the raw coal block in the collected raw coal sample to obtain the raw coal block standard sample, wherein the raw coal block standard sample has a diameter of 50 mm and a height of 100 mm.

[0011] In the first aspect, the macroscopic mechanical parameters include uniaxial compressive strength and elastic modulus.

[0012] In the first aspect, the nanoindentation test is performed on the slurry-coal binary interface sheet prepared in S1 to obtain the micromechanical parameters of the slurry-coal binary interface sheet, specifically including: S31, selecting the slurry-coal transition point of the slurry-coal binary interface sheet for nanoindentation experiment, and setting the test point for the test; S32, starting and preparing the nanoindentation instrument, ensuring that the instrument is in normal working condition, and selecting the probe according to the test requirements; S33, calibrating the nanoindentation instrument, and setting the working parameters of the nanoindentation instrument; S34, fixing the slurry-coal binary interface sheet on the sample stage of the nanoindentation instrument, ensuring that the surface of the slurry-coal binary interface sheet is parallel to the probe; S35, starting the indentation test, applying the loading speed through the nanoindentation instrument, and monitoring the indentation depth and indentation modulus through the deformation or stress sensor under the probe.

[0013] In the first aspect, the micromechanical parameters of the slurry-coal binary interface slice obtained by the S3 test are used to draw the indentation modulus cloud map of the slurry-coal binary interface slice test area, and the width of the interface transition zone is determined by dividing the measuring line, which specifically includes: S41, generating a modulus cloud map: drawing the indentation modulus cloud map of the measuring point area of ​​the slurry-coal binary interface slice according to the position of each measuring point of the nanoindentation test on the slurry-coal binary interface slice and its corresponding indentation modulus; S42, determining the measuring line: determining the horizontal and vertical measuring lines through the horizontal measuring points and vertical measuring points of the measuring point area of ​​the slurry-coal binary interface slice; S43, determining the horizontal mutation point of the indentation modulus: calculating the average indentation modulus of the slurry and coal rock on the horizontal measuring line, setting the indentation modulus of the horizontal measuring line to have a numerical deviation of more than 20% from the average indentation modulus of the corresponding slurry or coal rock, which is the indentation modulus. The horizontal mutation point of the indentation modulus, S44, determines the vertical consistency point of the indentation modulus: calculates the average indentation modulus of the vertical measuring line, and sets the numerical deviation between the indentation modulus of the vertical measuring line and the average indentation modulus of the vertical measuring line to be less than 10%, which is the vertical consistency point of the indentation modulus; S45, determines the measuring line range of the interface transition zone: after preliminarily determining the horizontal mutation point of the indentation modulus through S43, determines the vertical consistency point of the indentation modulus through S44 in the direction of the vertical measuring line of the horizontal mutation point to verify and determine the rationality of the horizontal mutation point, and then uses the vertical measuring line of the indentation modulus of the determined horizontal mutation point as the vertical boundary range of the slurry-coal binary interface transition zone; S46, determines the specific range of the interface transition zone: superimposes the vertical boundary range of the slurry-coal binary interface transition zone determined by S45 with the indentation modulus cloud map of the measuring point area drawn by S41 to determine the specific boundary of the slurry-coal binary interface transition zone.

[0014] In the first aspect, the indentation modulus cloud map of the slurry-coal binary interface slice test area drawn by S4 determines the area ratio of each area and the indentation modulus of each area, and obtains the average indentation modulus of the slurry-coal binary interface slice test area, specifically including: S51, using the specific boundary of the slurry-coal binary interface transition zone determined by S46, dividing the measuring point area into three parts: slurry, slurry-coal binary interface transition zone and coal rock, and determining the area ratio of the three parts: slurry, slurry-coal binary interface transition zone and coal rock, and the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock; S52, obtaining the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice by weightedly averaging the area ratio of the three parts: slurry, slurry-coal binary interface transition zone and coal rock with the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock.

[0015] In the first aspect, the obtaining of the fitting relationship between the macroscopic mechanical parameters obtained in S2 and the average indentation modulus of the slurry-coal binary interface thin slice region obtained in S5, and determining the macroscopic strength of the grouting interface transition zone according to the fitting relationship specifically include: S61, performing data fitting on the uniaxial compressive strength and elastic modulus of the macroscopic mechanical parameters of the slurry-coal cement body obtained in S2 test and the average indentation modulus of the measuring point region of the slurry-coal binary interface thin slice obtained in S52, to obtain fitting curves and formulas for uniaxial compressive strength, elastic modulus and average indentation modulus; S62, fitting the slurry and coal rock parts obtained in S51 test Substitute the average indentation modulus of the slurry-coal binary interface transition zone obtained by S51 into the formula obtained by S61 to obtain the uniaxial compressive strength and elastic modulus of each area of ​​the slurry and coal rock respectively; S63, verify the rationality of the determination method by comparing the uniaxial compressive strength and elastic modulus of the slurry and coal rock obtained by S62 with the uniaxial compressive strength and elastic modulus of the slurry and coal rock obtained by S2; S64, after the rationality of the determination method is verified by S63, substitute the average indentation modulus of the slurry-coal binary interface transition zone obtained by the S51 test into the formula obtained by S61 to obtain the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone.

[0016] Beneficial effects:

[0017] The method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone of the present invention comprises the following steps: preparing a slurry standard sample, a slurry-coal cement, a slurry-coal binary interface slice and a raw coal block standard sample respectively; then performing a uniaxial compression test on the slurry standard sample, the slurry-coal cement and the raw coal block standard sample to obtain the test values ​​of the uniaxial compressive strength and elastic modulus of the slurry standard sample, the slurry-coal cement and the raw coal block standard sample; then performing a micro-nanoindentation test on the slurry-coal binary interface slice, selecting a test area on the slurry-coal binary interface slice, the test area being the junction of the slurry and the coal rock, and then dividing the test area into test points, the test points covering the slurry and coal rock areas, and then performing a micro-nanoindentation test on the divided test points to obtain the indentation modulus and indentation modulus. depth; then, the horizontal test line and the vertical test line are divided according to the divided test points, and the horizontal mutation point of the transition zone between the slurry and the slurry-coal binary interface and the horizontal mutation point of the transition zone between the slurry-coal binary interface and the coal rock are determined on the horizontal test line according to the measured indentation modulus, and then the rationality of the two mutation points on the horizontal test line is verified by the indentation modulus on the vertical test line of the two mutation points on the horizontal test line, and the vertical boundary of the slurry-coal binary interface transition zone is obtained, thereby obtaining the approximate range of the slurry-coal binary interface transition zone; then, the indentation modulus cloud map of the test area of ​​the slurry-coal binary interface slice is drawn according to the test point position and indentation modulus on the slurry-coal binary interface slice, and the approximate range of the slurry-coal binary interface transition zone is superimposed with the drawn indentation modulus cloud map of the measuring point area , determine the specific boundary of the slurry-coal binary interface transition zone, divide the measuring point area into three parts: slurry, slurry-coal binary interface transition zone and coal rock according to the determined specific boundary of the slurry-coal binary interface transition zone, determine the area ratio of the slurry, slurry-coal binary interface transition zone and coal rock and the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock; then perform weighted average of the area ratio of the slurry, slurry-coal binary interface transition zone and coal rock and the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock respectively, and obtain the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice; compare the measured uniaxial compressive strength and elastic modulus of the slurry-coal cement with the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice The average indentation modulus is used for data fitting to obtain fitting curves and formulas of uniaxial compressive strength, elastic modulus and average indentation modulus; the average indentation modulus of the slurry and coal rock obtained by the test is then substituted into the obtained formula to obtain the uniaxial compressive strength and elastic modulus of each region of the slurry and coal rock, respectively; the uniaxial compressive strength and elastic modulus of the slurry and coal rock calculated by the formula are then compared with the uniaxial compressive strength and elastic modulus of the measured slurry standard sample and the original coal block standard sample to verify the rationality of the determination method; finally, after verifying that the determination method is rational, the average indentation modulus of the slurry-coal binary interface transition zone obtained by the test is substituted into the obtained formula to obtain the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone;The method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone of the present invention can accurately determine the boundary of the slurry-coal binary transition zone, and can uniformly standardize and quantify the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone, thereby enabling better research and understanding of the mechanical properties and behavior of the slurry-coal binary. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is the horizontal and vertical measuring lines for dividing the measuring point area of ​​the slurry-coal binary interface slice;

[0020] Figure 2 This is a test diagram of the slurry-coal binary interface thin section cast using slurry A. From left to right, it is the selection diagram of the overall test area, the selection diagram of the measurement point area divided by the measurement line, and the cloud diagram of the measurement point area divided by the measurement line;

[0021] Figure 3 This is a test diagram of the slurry-coal binary interface thin section cast using slurry B. From left to right, it is the selection diagram of the overall test area, the selection diagram of the measurement point area for dividing the measurement line, and the cloud diagram of the measurement point area for dividing the measurement line;

[0022] Figure 4 This is a test diagram of a slurry-coal binary interface thin section cast using C slurry. From left to right, it includes the selection diagram of the entire test area, the selection diagram of the measurement point area for dividing the measurement line, and the cloud diagram of the measurement point area for dividing the measurement line.

[0023] Figure 5 This is a test diagram of the slurry-coal binary interface thin section cast using D slurry. From left to right, it is the selection diagram of the overall test area, the selection diagram of the measurement point area divided by the measurement line, and the cloud diagram of the measurement point area divided by the measurement line;

[0024] Figure 6 The boundary distinction and area proportion of the slurry, slurry-coal binary interface transition zone and coal rock in the measuring point area of ​​the dividing measuring line of the slurry-coal binary interface thin section cast by slurry A;

[0025] Figure 7 The boundary distinction and area proportion of the slurry, slurry-coal binary interface transition zone and coal rock in the measuring point area of ​​the dividing measuring line of the slurry-coal binary interface thin section cast by B slurry;

[0026] Figure 8The boundary distinction and area proportion of the slurry, slurry-coal binary interface transition zone and coal rock in the measuring point area of ​​the dividing measuring line of the slurry-coal binary interface thin section cast by C slurry;

[0027] Figure 9 The boundary distinction and area proportion of the slurry, slurry-coal binary interface transition zone and coal rock in the measuring point area of ​​the dividing measuring line of the slurry-coal binary interface thin section cast by D slurry;

[0028] Figure 10 is the fitting diagram of average indentation modulus, macroscopic uniaxial compressive strength and elastic modulus;

[0029] Figure 11 This is a comparison chart of the uniaxial compressive strength of slurry and coal rock in slurry-coal binary interface thin slices cast by slurry A, slurry B, slurry C and slurry D, and the uniaxial compressive strength of slurry standard samples cast by slurry A, slurry B, slurry C and slurry D, as well as the standard sample of raw coal block;

[0030] Figure 12 This is a comparison chart of the elastic moduli of the slurry and coal rock in the slurry-coal binary interface thin slices cast by slurry A, slurry B, slurry C and slurry D, and the elastic moduli of the slurry standard samples cast by slurry A, slurry B, slurry C and slurry D, as well as the original coal block standard sample. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this invention.

[0032] Example 1

[0033] like Figures 1 to 12As shown, the present embodiment 1 provides a method for determining the width and macroscopic strength of the transition zone of the grouting reinforcement interface, which is characterized in that the determination method specifically includes: S1, sample preparation: collecting raw coal samples, screening the raw coal samples, and making slurry standard samples, slurry-coal cement, slurry-coal binary interface slices and raw coal block standard samples respectively; S2, macroscopic mechanical parameter test: carrying out uniaxial compression test on the slurry standard sample, slurry-coal cement and raw coal block standard sample prepared by S1 to test the macroscopic mechanical parameters; S3, microscopic nanoindentation test: carrying out nanoindentation test on the slurry-coal binary interface slice prepared by S1 to obtain the microscopic mechanical parameters of the slurry-coal binary interface slice; S4, determination of the width of the transition zone of the grouting reinforcement interface: measuring the slurry standard sample by S3. The micromechanical parameters of the slurry-coal binary interface slice obtained by the test are used to draw the indentation modulus cloud map of the slurry-coal binary interface slice test area, and the width of the interface transition zone is determined by dividing the measuring line; S5, microparameters of the grouting reinforcement interface transition zone: the area proportion of each area and the average indentation modulus of each area are determined by the indentation modulus cloud map of the slurry-coal binary interface slice test area drawn by S4, and the average indentation modulus of the slurry-coal binary interface slice test area is obtained by weighted calculation of the area proportion; S6, macroscopic strength of the grouting reinforcement interface transition zone: the fitting relationship between the macroscopic mechanical parameters obtained by S2 and the average indentation modulus of the slurry-coal binary interface slice test area obtained by S5 is obtained, and the macroscopic strength of the grouting interface transition zone is determined according to the fitting relationship.

[0034] The method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone of the present invention comprises the following steps: preparing a slurry standard sample, a slurry-coal cement, a slurry-coal binary interface slice and a raw coal block standard sample respectively; then performing a uniaxial compression test on the slurry standard sample, the slurry-coal cement and the raw coal block standard sample to obtain the test values ​​of the uniaxial compressive strength and elastic modulus of the slurry standard sample, the slurry-coal cement and the raw coal block standard sample; then performing a micro-nanoindentation test on the slurry-coal binary interface slice, selecting a test area on the slurry-coal binary interface slice, the test area being the junction of the slurry and the coal rock, and then dividing the test area into test points, the test points covering the slurry and coal rock areas, and then performing a micro-nanoindentation test on the divided test points to obtain the indentation modulus and indentation modulus. depth; then, the horizontal test line and the vertical test line are divided according to the divided test points, and the horizontal mutation point of the transition zone between the slurry and the slurry-coal binary interface and the horizontal mutation point of the transition zone between the slurry-coal binary interface and the coal rock are determined on the horizontal test line according to the measured indentation modulus, and then the rationality of the two mutation points on the horizontal test line is verified by the indentation modulus on the vertical test line of the two mutation points on the horizontal test line, and the vertical boundary of the slurry-coal binary interface transition zone is obtained, thereby obtaining the approximate range of the slurry-coal binary interface transition zone; then, the indentation modulus cloud map of the test area of ​​the slurry-coal binary interface slice is drawn according to the test point position and indentation modulus on the slurry-coal binary interface slice, and the approximate range of the slurry-coal binary interface transition zone is superimposed with the drawn indentation modulus cloud map of the measuring point area , determine the specific boundary of the slurry-coal binary interface transition zone, divide the measuring point area into three parts: slurry, slurry-coal binary interface transition zone and coal rock according to the determined specific boundary of the slurry-coal binary interface transition zone, determine the area ratio of the slurry, slurry-coal binary interface transition zone and coal rock and the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock; then perform weighted average of the area ratio of the slurry, slurry-coal binary interface transition zone and coal rock and the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock respectively, and obtain the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice; compare the measured uniaxial compressive strength and elastic modulus of the slurry-coal cement with the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice The average indentation modulus is used for data fitting to obtain fitting curves and formulas of uniaxial compressive strength, elastic modulus and average indentation modulus; the average indentation modulus of the slurry and coal rock obtained by the test is then substituted into the obtained formula to obtain the uniaxial compressive strength and elastic modulus of each region of the slurry and coal rock, respectively; the uniaxial compressive strength and elastic modulus of the slurry and coal rock calculated by the formula are then compared with the uniaxial compressive strength and elastic modulus of the measured slurry standard sample and the original coal block standard sample to verify the rationality of the determination method; finally, after verifying that the determination method is rational, the average indentation modulus of the slurry-coal binary interface transition zone obtained by the test is substituted into the obtained formula to obtain the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone;The method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone of the present invention can accurately determine the boundary of the slurry-coal binary transition zone, and can uniformly standardize and quantify the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone, thereby enabling better research and understanding of the mechanical properties and behavior of the slurry-coal binary.

[0035] In some possible implementations, the preparation of the slurry standard sample specifically includes: pouring the slurry to obtain a standard cylindrical sample, and curing the poured standard cylindrical sample for 28 days in an environment with a temperature of 20°C to 25°C and a humidity greater than 95% to obtain a slurry standard sample.

[0036] Specifically, the standard cylindrical specimen for slurry casting is a cylindrical specimen with a diameter of 50 mm and a height of 100 mm. The slurry is a mixture of water and ash. In the determination method of the present invention, no less than 4 groups of different slurries are required. Usually, the slurry includes at least ultrafine silicate cement slurry with a water-cement ratio of 0.3, ultrafine silicate cement slurry with a water-cement ratio of 0.4, conventional sulfoaluminate cement slurry with a water-cement ratio of 0.4, and conventional silicate cement slurry with a water-cement ratio of 0.4.

[0037] In some possible implementations, the preparation of the slurry coal cement specifically includes: selecting broken coal blocks from the screened raw coal sample, pouring slurry on the selected broken coal blocks to obtain a slurry coal cement test block, wherein the slurry coal cement test block is a cube with a size of 150 mm × 150 mm × 150 mm; curing the cast slurry coal cement test block in an environment with a temperature of 20°C to 25°C and a humidity greater than 95% for 28 days, and then drilling a core from the slurry coal cement test block to obtain a slurry coal cement standard sample, wherein the slurry coal cement standard sample is a cube with a diameter of 5 0mm, a cylindrical sample with a height of 100mm; the preparation of the slurry-coal binary interface slice specifically includes: cutting the prepared slurry-coal cement standard sample along the radial direction, and fine-grinding and polishing the cut sample surface to obtain a slurry-coal binary interface slice, the slurry-coal binary interface slice has a diameter of 50mm and a height of 25mm; the preparation of the raw coal block standard sample specifically includes: linearly cutting the raw coal block in the collected raw coal sample to obtain a raw coal block standard sample, the raw coal block standard sample has a diameter of 50mm and a height of 100mm.

[0038] Specifically, at the grouting construction site, the coal rock with a larger proportion has a particle size range of 16.0-19.0mm, 19.0-31.5mm, and 31.5-37.5mm, and the smaller coal rocks are scattered on the ground. Therefore, the particle size range of the selected crushed coal rock includes 16.0-19.0mm, 19.0-31.5mm, and 31.5-37.5mm. There are no requirements for the ratio of the slurry of the cast slurry-coal cement to the crushed coal blocks, as well as the ratio of the crushed coal blocks in each particle size range.

[0039] In some possible implementations, the macroscopic mechanical parameters include uniaxial compressive strength and elastic modulus; the nanoindentation test is performed on the slurry-coal binary interface sheet prepared in S1 to obtain the micromechanical parameters of the slurry-coal binary interface sheet, specifically including: S31, selecting the slurry-coal transition point of the slurry-coal binary interface sheet for nanoindentation experiment, and setting test points for testing; S32, starting and preparing the nanoindentation instrument, ensuring that the instrument is in normal working condition, and selecting the probe according to the test requirements; S33, calibrating the nanoindentation instrument and setting the working parameters of the nanoindentation instrument; S34, fixing the slurry-coal binary interface sheet on the sample stage of the nanoindentation instrument, ensuring that the surface of the slurry-coal binary interface sheet is parallel to the probe; S35, starting the indentation test, applying the loading speed through the nanoindentation instrument, and monitoring the indentation depth and indentation modulus through the deformation or stress sensor under the probe.

[0040] Specifically, by conducting nanoindentation tests on the slurry-coal binary interface slice, the indentation modulus of each test point of the slurry-coal binary interface slice is obtained. At the same time, the indentation modulus cloud map of the measuring point area can be drawn according to the position of each test point and the measured indentation modulus, in preparation for the subsequent determination of the specific boundary of the slurry-coal binary interface transition zone; the indentation depth is monitored, and the recovery behavior of the sample can be judged by whether the monitored indentation depth curve fluctuates after unloading the loading speed after the indentation test.

[0041] In some possible implementations, the micromechanical parameters of the slurry-coal binary interface slice obtained by the S3 test are used to draw an indentation modulus cloud map of the slurry-coal binary interface slice test area, and the width of the interface transition zone is determined by dividing the measuring line. Specifically, the following steps are used: S41, generating a modulus cloud map: drawing an indentation modulus cloud map of the measuring point area of ​​the slurry-coal binary interface slice according to the positions of the measuring points of the nanoindentation test on the slurry-coal binary interface slice and their corresponding indentation moduli; S42, determining the measuring line: determining the horizontal and vertical measuring lines through the horizontal and vertical measuring points of the measuring point area of ​​the slurry-coal binary interface slice; S43, determining the horizontal mutation point of the indentation modulus: calculating the average indentation modulus of the slurry and coal rock on the horizontal measuring line, setting the indentation modulus of the horizontal measuring line to have a numerical deviation of more than 20% from the average indentation modulus of the corresponding slurry or coal rock, that is, the indentation modulus. The horizontal mutation point of the indentation modulus, S44, determines the vertical consistency point of the indentation modulus: calculates the average indentation modulus of the vertical measuring line, and sets the numerical deviation between the indentation modulus of the vertical measuring line and the average indentation modulus of the vertical measuring line to be less than 10%, which is the vertical consistency point of the indentation modulus; S45, determines the measuring line range of the interface transition zone: after preliminarily determining the horizontal mutation point of the indentation modulus through S43, determines the vertical consistency point of the indentation modulus through S44 in the vertical measuring line direction of the horizontal mutation point to verify and determine the rationality of the horizontal mutation point, and then uses the indentation modulus vertical measuring line of the determined horizontal mutation point as the vertical boundary range of the slurry-coal binary interface transition zone; S46, determines the specific range of the interface transition zone: superimposes the vertical boundary range of the slurry-coal binary interface transition zone determined by S45 with the indentation modulus cloud map of the measuring point area drawn by S41 to determine the specific boundary of the slurry-coal binary interface transition zone.

[0042] Specifically, by drawing the indentation modulus cloud map of the measuring point area of ​​the slurry-coal binary interface thin slice and superimposing it with the vertical boundary range of the determined slurry-coal binary interface transition zone, the specific boundary of the slurry-coal binary interface transition zone can be determined. At this time, the boundary of the slurry-coal binary interface transition zone is more accurate.

[0043] In some possible implementations, the indentation modulus cloud map of the slurry-coal binary interface slice test area drawn by S4 determines the area ratio of each area and the indentation modulus of each area, and obtains the average indentation modulus of the slurry-coal binary interface slice test area, specifically including: S51, using the specific boundary of the slurry-coal binary interface transition zone determined by S46, dividing the measuring point area into three parts: slurry, slurry-coal binary interface transition zone and coal rock, and determining the area ratio of the slurry, slurry-coal binary interface transition zone and coal rock and the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock; S52, obtaining the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice by weightedly averaging the area ratio of the slurry, slurry-coal binary interface transition zone and coal rock with the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock.

[0044] Specifically, the precise boundary of the slurry-coal binary interface transition zone is determined, and the test area can be accurately divided into three parts: the slurry, the slurry-coal binary interface transition zone, and the coal rock. The area proportion of each region can be obtained, and the average indentation modulus of each region can be calculated by software. Then, the area proportions of the slurry, the slurry-coal binary interface transition zone, and the coal rock are weighted averaged with the average indentation modulus of the slurry, the slurry-coal binary interface transition zone, and the coal rock regions, respectively, to obtain the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice, in preparation for subsequent data fitting.

[0045] In some possible implementations, the obtaining of the fitting relationship between the macroscopic mechanical parameters obtained in S2 and the average indentation modulus of the slurry-coal binary interface slice region obtained in S5, and determining the macroscopic strength of the grouting interface transition zone according to the fitting relationship specifically include: S61, performing data fitting on the uniaxial compressive strength and elastic modulus of the macroscopic mechanical parameters of the slurry-coal cement body obtained in S2 test and the average indentation modulus of the measuring point region of the slurry-coal binary interface slice obtained in S52, to obtain fitting curves and formulas for uniaxial compressive strength, elastic modulus and average indentation modulus; S62, fitting the slurry and coal rock obtained in S51 test to obtain the fitting curves and formulas for uniaxial compressive strength, elastic modulus and average indentation modulus. Substitute the average indentation modulus of the part into the formula obtained in S61 to obtain the uniaxial compressive strength and elastic modulus of each area of ​​the slurry and coal rock respectively; S63, verify the rationality of the determination method by comparing the uniaxial compressive strength and elastic modulus of the slurry and coal rock obtained in S62 with the uniaxial compressive strength and elastic modulus of the slurry and coal rock obtained in S2; S64, after the rationality of the determination method is verified by S63, substitute the average indentation modulus of the slurry-coal binary interface transition zone obtained by the S51 test into the formula obtained in S61 to obtain the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone.

[0046] Specifically, the uniaxial compressive strength and elastic modulus of the slurry-coal cement body are fitted with the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice through the software to obtain the fitting curve and formula of the uniaxial compressive strength, elastic modulus and average indentation modulus. The formula can be substituted into the average indentation modulus of the slurry and coal rock area of ​​the slurry-coal binary interface slice to obtain the uniaxial compressive strength and elastic modulus of the slurry and coal rock area of ​​the slurry-coal binary interface slice. The uniaxial compressive strength and elastic modulus of the slurry and coal rock area of ​​the slurry-coal binary interface slice are obtained by comparing the obtained uniaxial compressive strength and elastic modulus of the slurry and coal rock area of ​​the slurry-coal binary interface slice with the measured point area. The uniaxial compressive strength and elastic modulus of the slurry standard sample and the original coal block standard sample obtained by the test are compared to verify the error between the test value and the calculated value by the formula. The feasibility of the method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone of the present invention is verified by the amount of the error value. Then, the average indentation modulus of the slurry-coal binary interface transition zone of the slurry-coal binary interface slice is substituted into the formula to obtain the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone, which can make the uniaxial compressive strength and elastic modulus values ​​of the interface transition zone have uniform standardization and quantification.

[0047] In order to further illustrate the technical solution of the present application in detail to support the technical problem to be solved by the present application, the preparation method is described below with specific examples, such as Example 1.

[0048] Example 1

[0049] A method for determining the width and macroscopic strength of a grouting reinforcement interface transition zone, the method specifically comprising:

[0050] Sample preparation: Raw coal samples were collected from the working face of the coal mine, and the collected crushed coal rock was sieved using a new standard square hole sieve with a diameter of 5-50 mm to determine the proportion of coal rock in the sieve hole range. Crushed coal rock with particle sizes in the range of 16.0-19.0 mm, 19.0-31.5 mm, and 31.5-37.5 mm were selected, and ultrafine Portland cement, conventional sulphoaluminate cement, and conventional Portland cement were used to prepare ultrafine Portland cement slurries with a water-cement ratio of 0.3, ultrafine Portland cement slurries with a water-cement ratio of 0.4, conventional sulphoaluminate cement slurries with a water-cement ratio of 0.4, and water-cement ratio of 0.5, respectively. Conventional silicate cement slurries with a ash ratio of 0.4 were marked as slurry A, slurry B, slurry C and slurry D respectively; then the four slurries A, B, C and D were mixed with the screened crushed coal rock to obtain cubic specimens A, cubic specimen B, cubic specimen C and cubic specimen D with a size of 150 mm × 150 mm × 150 mm, and the slurry-coal cemented test blocks A, slurry-coal cemented test blocks B, slurry-coal cemented test blocks C and slurry-coal cemented test blocks D were cured for 28 days at a temperature of 24°C and a humidity greater than 95%. Then, a straight line was drilled from the slurry-coal cemented test blocks by drilling and coring. A slurry-coal cement, B slurry-coal cement, C slurry-coal cement and D slurry-coal cement with a diameter of 50 mm and a height of 100 mm were prepared. Two groups of each sample were made, and the subsequent test data were averaged. The prepared A slurry-coal cement, B slurry-coal cement, C slurry-coal cement and D slurry-coal cement were cut along the radial direction, and the cut sample surfaces were finely ground and polished to obtain A slurry-coal binary interface slices, B slurry-coal binary interface slices, C slurry-coal binary interface slices and D slurry-coal binary interface slices. The diameter of the slurry-coal binary interface slices was 50 mm and the average height was 100 mm. The diameter of the slurries A, B, C and D were respectively cast to obtain standard cylindrical specimens with a diameter of 50 mm and a height of 100 mm. The cast standard cylindrical specimens were cured for 28 days in an environment with a temperature of 20°C to 25°C and a humidity greater than 95% to obtain standard specimens of slurry A, slurry B, slurry C and slurry D. Two groups of each specimen were prepared, and the average value of the subsequent test data was taken. The raw coal blocks in the collected raw coal samples were linearly cut to obtain standard specimens of raw coal blocks with a diameter of 50 mm and a height of 100 mm. Two groups of each specimen were prepared, and the average value of the subsequent test data was taken.

[0051] Macro-mechanical parameter test: The RMT-150C specimen device was used to conduct uniaxial compression tests on A slurry-coal cement, B slurry-coal cement, C slurry-coal cement, D slurry-coal cement, A slurry standard sample, B slurry standard sample, C slurry standard sample, D slurry standard sample and raw coal block standard sample. The corresponding uniaxial compressive strength and elastic modulus of the samples were obtained, as shown in Table 1.

[0052] Microscopic nanoindentation test: The HYSITRON TIPREMIER nanoindentation tester of BRUKER was used to conduct nanoindentation experiments on the slurry-coal transition of the prepared A slurry-coal binary interface slice, B slurry-coal binary interface slice, C slurry-coal binary interface slice and D slurry-coal binary interface slice. The vertical and horizontal test point spacing was set to 10 μm, and a total of 49 test points were tested. Figure 1 As shown; start and prepare the nanoindentation instrument, ensure that the instrument is in normal working condition, the selected probe is a triangular pyramid diamond probe, the maximum indentation load is ≥10mN, the load resolution is ≤1nN, and the maximum indentation depth is ≥5μm. The scanning in-situ control accuracy is <±10nm, the optical resolution in the optical imaging system is ≤3μm, the high-precision positioning platform XY direction movement range is ≥150nm×150nm, the step resolution in both directions is ≤50nm, the height direction movable range is ≥50mm, the resolution is ≤3nm, and the curvature radius of the indenter tip during the test is generally between 20 and 200nm; calibrate the nanoindentation instrument, set the nanoindentation instrument working parameters; place A slurry-coal binary interface thin slice, B slurry-coal binary interface thin slice, C slurry-coal binary interface thin slice and D slurry-coal binary interface thin slice on the surface of the nanoindenter; One side of the sheet is finely ground and polished, and the other side is coated with glue and attached with an iron sheet to ensure that the sample is better adsorbed on the sample table to prevent the test offset from affecting the results during the test, and to ensure that the surface of the slurry-coal binary interface sheet is parallel to the probe; the indentation test is started, and the load force is applied to 3mN at a constant loading speed of 300μN / s using the nanoindentation instrument. The indentation depth and indentation modulus of the test point are monitored by the deformation or stress sensor under the probe. The load is stabilized at the maximum load for 2 seconds to eliminate the creep effect, and then the load force is unloaded to 0μN at a constant loading speed of 300μN / s;

[0053] Determination of the width of the transition zone of the grouting reinforcement interface: According to the positions of the measuring points of the nanoindentation test on the slurry-coal binary interface slice and their corresponding indentation moduli, a cloud map of the indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice is drawn; the horizontal and vertical measuring lines are determined by the horizontal and vertical measuring points of the measuring point area of ​​the slurry-coal binary interface slice, such as Figure 1As shown; calculate the average indentation modulus of the slurry and coal rock of the horizontal measuring line, set the numerical deviation of the indentation modulus of the horizontal measuring line and the average indentation modulus of the corresponding slurry or coal rock to be greater than 20%, that is, the horizontal mutation point of the indentation modulus, calculate the average indentation modulus of the vertical measuring line, set the numerical deviation of the indentation modulus of the vertical measuring line and the average indentation modulus of the vertical measuring line to be less than 10%, that is, the vertical consistency point of the indentation modulus; after determining the horizontal mutation point of the indentation modulus, determine the vertical consistency point of the indentation modulus in the direction of the vertical measuring line of the horizontal mutation point to verify and determine the horizontal mutation point, and then use the indentation modulus vertical consistency point measuring line of the determined horizontal mutation point as the vertical boundary range of the slurry-coal binary interface transition zone; superimpose the determined vertical boundary range of the slurry-coal binary interface transition zone with the drawn indentation modulus cloud map of the measuring point area to determine the specific boundary of the slurry-coal binary interface transition zone, as shown Figure 2 、 Figure 3 、 Figure 4 and Figure 5 As shown;

[0054] Microscopic parameters of the grouting reinforcement interface transition zone: The specific boundary of the slurry-coal binary interface transition zone is determined by the indentation modulus cloud map, and the measuring point area is divided into three parts: slurry, slurry-coal binary interface transition zone, and coal rock. The area proportions of the three parts, slurry, slurry-coal binary interface transition zone, and coal rock, and the average indentation modulus of each area of ​​slurry, slurry-coal binary interface transition zone, and coal rock are determined by software, such as Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 and Figure 9 As shown in Table 2, the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice is obtained by weightedly averaging the area proportions of the slurry, slurry-coal binary interface transition zone and coal rock with the average indentation modulus of the slurry, slurry-coal binary interface transition zone and coal rock, respectively.

[0055] Macro strength of grouting reinforcement interface transition zone: According to the uniaxial compressive strength and elastic modulus of the macroscopic mechanical parameters of the slurry-coal cement body obtained by the test and the average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice, the fitting curve and formula of uniaxial compressive strength, elastic modulus and average indentation modulus are obtained. The fitting curve is as follows: Figure 10 As shown, the fitting formulas are as follows: (1) and (2); the average indentation modulus of the slurry and coal rock obtained by the test is substituted into the obtained formula to obtain the uniaxial compressive strength and elastic modulus of each region of the slurry and coal rock, as shown in Table 3; the uniaxial compressive strength and elastic modulus of the slurry and coal rock obtained by the test are compared with the uniaxial compressive strength and elastic modulus of the slurry and coal rock obtained by the test, as shown in Table 3. Figure 11 and Figure 12 As shown in Table 3, the rationality of the determination method is verified; after verifying that the determination method is rational, the indentation modulus of the slurry-coal binary interface transition zone obtained by the test is substituted into the obtained formula to obtain the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone, as shown in Table 3.

[0056] The test results of Example 1 are as follows:

[0057] Table 1 Uniaxial compression test results of standard samples of slurry A, slurry B, slurry C, slurry D, slurry-coal cement A, slurry-coal cement B, slurry-coal cement C, slurry-coal cement D and raw coal block

[0058] Sample Uniaxial compressive strengthσ / MPa Elastic modulus E / GPa A slurry standard sample 31.57 10.18 B slurry standard sample 22.83 7.08 C slurry standard sample 17.21 5.33 D slurry standard sample 14.63 4.22 A slurry-coal cement 18.91 5.85 B slurry-coal cement 15.62 4.54 C slurry-coal cement 13.03 3.75 D slurry-coal cement 11.43 2.9 Standard sample of raw coal 12.45 3.39

[0059] Table 2 Indentation modulus of slurry, slurry-coal binary interface transition zone and coal rock in the measuring point area of ​​A slurry-coal binary interface slice, B slurry-coal binary interface slice, C slurry-coal binary interface slice and D slurry-coal binary interface slice

[0060]

[0061] Fitting formula: The average indentation modulus in Table 2 is linearly fitted with the uniaxial compressive strength and elastic modulus of the slurry-coal cement in Table 1 to obtain the linear fitting curve of uniaxial compressive strength, elastic modulus and indentation modulus. The fitting curve is as follows: Figure 10 As shown, the fitting formulas obtained are as follows:

[0062] σ=0.81E D +6.11(R 2 =0.94) Formula (1)

[0063] E=0.31E D +0.92(R 2 =0.95) Formula (2)

[0064] Where, σ is the uniaxial compressive strength; E is the elastic modulus; E D is the indentation modulus.

[0065] Table 3 Uniaxial compressive strength and elastic modulus of the slurry, slurry-coal binary interface transition zone, and coal rock in A slurry-coal binary interface slice, B slurry-coal binary interface slice, C slurry-coal binary interface slice, and D slurry-coal binary interface slice

[0066]

[0067]

[0068] (Note: Since the slurries in the A-coal binary interface sheet, B-coal binary interface sheet, C-coal binary interface sheet, and D-coal binary interface sheet are different but the coal rock is the same, when calculating, the indentation modulus of the slurry substituted into the formula is the indentation modulus of each of the slurries in the A-coal binary interface sheet, B-coal binary interface sheet, C-coal binary interface sheet, and D-coal binary interface sheet, and the indentation modulus of the coal rock substituted into the formula is the average value of the sum of the indentation moduli of the coal rock in the A-coal binary interface sheet, B-coal binary interface sheet, C-coal binary interface sheet, and D-coal binary interface sheet.)

[0069] By comparing the uniaxial compressive strength and elastic modulus of each region of the slurry and coal rock in the A slurry-coal binary interface slice, B slurry-coal binary interface slice, C slurry-coal binary interface slice and D slurry-coal binary interface slice in Table 3 with the uniaxial compressive strength and elastic modulus of the A slurry standard sample, B slurry standard sample, C slurry standard sample, D slurry standard sample, A slurry-coal cement, B slurry-coal cement, C slurry-coal cement, D slurry-coal cement and original coal block standard sample in Table 1, it was found that the uniaxial compressive strength of the A slurry standard sample, B slurry standard sample, C slurry standard sample, D slurry standard sample and original coal block standard sample obtained by uniaxial compression test was similar to that of the A slurry-coal binary interface slice, B slurry-coal binary interface slice, C slurry-coal binary interface slice and D slurry-coal binary interface slice obtained by calculation. The errors in the uniaxial compressive strength of the slurry and coal rock in the interface slices are 2.9%, 6.5%, 8.1%, 9.5% and 3.5%, respectively; the errors in the elastic modulus of the A slurry standard sample, B slurry standard sample, C slurry standard sample, D slurry standard sample and the original coal block standard sample obtained by uniaxial compression test and the elastic modulus of the slurry and coal rock in the A slurry-coal binary interface slice, B slurry-coal binary interface slice, C slurry-coal binary interface slice and D slurry-coal binary interface slice obtained by calculation are 8.2%, 4.7%, 13.1%, 13.9% and 6.2%, respectively; the above error values ​​are all less than 20%, which are within the allowable error range. Therefore, it can be considered that the data of the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone calculated by the determination method of the present invention are feasible.

[0070] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for determining the width and macroscopic strength of the transition zone of a grouting reinforcement interface, characterized in that: The determination method specifically includes: S1. Sample preparation: Collect raw coal samples, screen them, and prepare slurry standard samples, slurry-coal cement, slurry-coal binary interface slices, and raw coal block standard samples; S2. Macro-mechanical parameter test: Uniaxial compression test was carried out on the slurry standard sample, slurry coal cement and raw coal block standard sample prepared in S1 to test the macro-mechanical parameters; S3. Microscopic nanoindentation test: Nanoindentation test is performed on the slurry-coal binary interface slice prepared in S1 to obtain the micromechanical parameters of the slurry-coal binary interface slice; S4. Determination of the width of the grouting reinforcement interface transition zone: Based on the micromechanical parameters of the slurry-coal binary interface slice obtained in S3, a cloud diagram of the indentation modulus of the slurry-coal binary interface slice test area is drawn, and the width of the interface transition zone is determined by dividing the test line; S5. Microscopic parameters of the grouting reinforcement interface transition zone: The area ratio of each region and the average indentation modulus of each region are determined by the indentation modulus cloud map of the slurry-coal binary interface thin section test area drawn in S4. The average indentation modulus of the slurry-coal binary interface thin section test area is obtained by weighted calculation based on the area ratio; S6. Macroscopic strength of the grouting reinforcement interface transition zone: obtain the fitting relationship between the macroscopic mechanical parameters obtained in S2 and the average indentation modulus of the slurry-coal binary interface thin section test area obtained in S5, and determine the macroscopic strength of the grouting interface transition zone based on the fitting relationship.

2. A method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone according to claim 1, characterized in that: The preparation of the slurry standard sample specifically includes: The slurry is cast to obtain a standard cylindrical specimen, and the cast standard cylindrical specimen is cured for 28 days in an environment with a temperature of 20° C. to 25° C. and a humidity greater than 95% to obtain a slurry standard specimen.

3. A method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone according to claim 2, characterized in that: The preparation of the slurry coal cement body specifically includes: Broken coal blocks are selected from the screened raw coal samples, and slurry is poured on the selected broken coal blocks to obtain a slurry-coal cement test block, which is a cube with a size of 150mm×150mm×150mm; after the cast slurry-coal cement test block is cured for 28 days in an environment with a temperature of 20℃~25℃ and a humidity greater than 95%, a slurry-coal cement standard sample is drilled from the slurry-coal cement test block by drilling and coring, and the slurry-coal cement standard sample is a cylindrical sample with a diameter of 50mm and a height of 100mm.

4. A method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone according to claim 3, characterized in that: The preparation of the slurry-coal binary interface sheet specifically includes: The prepared slurry-coal cement standard sample was cut along the radial direction, and the cut sample surface was finely ground and polished to obtain a slurry-coal binary interface slice, wherein the diameter of the slurry-coal binary interface slice was 50 mm and the height was 25 mm.

5. A method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone according to claim 4, characterized in that: The preparation of the standard sample of raw coal block specifically includes: The raw coal blocks in the collected raw coal samples are linearly cut to obtain raw coal block standard samples, wherein the diameter of the raw coal block standard samples is 50 mm and the height is 100 mm.

6. A method for determining the width and macroscopic strength of a grouting reinforcement interface transition zone according to claim 5, characterized in that: The macroscopic mechanical parameters include uniaxial compressive strength and elastic modulus.

7. A method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone according to claim 6, characterized in that: The nanoindentation test is performed on the slurry-coal binary interface slice prepared in S1 to obtain the micromechanical parameters of the slurry-coal binary interface slice, which specifically include: S31, selecting the slurry-coal transition portion of the slurry-coal binary interface slice for nanoindentation testing, and setting test points for testing; S32. Start and prepare the nanoindentation instrument, ensure that the instrument is in normal working condition, and select the probe according to the test requirements; S33, calibrating the nanoindentation instrument and setting the working parameters of the nanoindentation instrument; S34, fixing the slurry-coal binary interface sheet on the sample stage of the nanoindentation instrument, ensuring that the surface of the slurry-coal binary interface sheet is parallel to the probe; S35. Start the indentation test, apply the loading speed through the nanoindentation instrument, and monitor the indentation depth and indentation modulus through the deformation or stress sensor under the probe.

8. A method for determining the width and macroscopic strength of the grouting reinforcement interface transition zone according to claim 7, characterized in that: The micromechanical parameters of the slurry-coal binary interface slice obtained by the S3 test, the indentation modulus cloud diagram of the slurry-coal binary interface slice test area, and the width of the interface transition zone determined by dividing the test line specifically include: S41, generating a modulus cloud map: drawing an indentation modulus cloud map of the measuring point area of ​​the slurry-coal binary interface slice according to the positions of each measuring point of the nanoindentation test on the slurry-coal binary interface slice and the corresponding indentation modulus; S42, determining a measuring line: determining horizontal and vertical measuring lines through horizontal and vertical measuring points in the measuring point area of ​​the slurry-coal binary interface slice; S43, determining the horizontal mutation point of the indentation modulus: calculating the average indentation modulus of the slurry and coal rock of the horizontal measurement line, setting the horizontal mutation point of the indentation modulus when the deviation between the indentation modulus of the horizontal measurement line and the corresponding average indentation modulus of the slurry or coal rock is greater than 20%. S44, determining the vertical consistency point of the indentation modulus: calculating the average indentation modulus of the vertical measuring line, and setting the vertical consistency point of the indentation modulus when the deviation between the indentation modulus of the vertical measuring line and the average indentation modulus of the vertical measuring line is less than 10%; S45. Determine the measurement line range of the interface transition zone: After preliminarily determining the horizontal mutation point of the indentation modulus through S43, determine the vertical consistency point of the indentation modulus through S44 in the direction of the measurement line perpendicular to the horizontal mutation point to verify and determine the rationality of the horizontal mutation point. Then, use the vertical measurement line of the indentation modulus at the determined horizontal mutation point as the vertical boundary range of the slurry-coal binary interface transition zone; S46. Determine the specific range of the interface transition zone: superimpose the vertical boundary range of the slurry-coal binary interface transition zone determined in S45 with the indentation modulus cloud map of the measuring point area drawn in S41 to determine the specific boundary of the slurry-coal binary interface transition zone.

9. A method for determining the width and macroscopic strength of a grouting reinforcement interface transition zone according to claim 8, characterized in that: The indentation modulus cloud map of the slurry-coal binary interface slice test area drawn by S4 determines the area proportion of each region and the indentation modulus of each region, and obtains the average indentation modulus of the slurry-coal binary interface slice test area, specifically including: S51. Using the specific boundary of the slurry-coal binary interface transition zone determined in S46, the measuring point area is divided into three parts: slurry, slurry-coal binary interface transition zone, and coal rock. The area ratios of the slurry, slurry-coal binary interface transition zone, and coal rock are determined, as well as the average indentation modulus of the slurry, slurry-coal binary interface transition zone, and coal rock regions. S52. The average indentation modulus of the measuring point area of ​​the slurry-coal binary interface slice is obtained by weightedly averaging the area proportions of the slurry, the slurry-coal binary interface transition zone and the coal rock with the average indentation modulus of the slurry, the slurry-coal binary interface transition zone and the coal rock.

10. A method for determining the width and macroscopic strength of a grouting reinforcement interface transition zone according to claim 9, characterized in that: The obtaining of the fitting relationship between the macroscopic mechanical parameters obtained in S2 and the average indentation modulus of the slurry-coal binary interface thin slice region obtained in S5, and determining the macroscopic strength of the grouting interface transition zone according to the fitting relationship specifically includes: S61. Performing data fitting on the uniaxial compressive strength and elastic modulus of the macroscopic mechanical parameters of the slurry-coal cement obtained from the test in S2 and the average indentation modulus of the measuring point region of the slurry-coal binary interface slice obtained from S52 to obtain fitting curves and formulas for the uniaxial compressive strength, elastic modulus, and average indentation modulus; S62. Substitute the average indentation modulus of the slurry and coal rock obtained from the test in S51 into the formula obtained in S61 to obtain the uniaxial compressive strength and elastic modulus of each region of the slurry and coal rock, respectively; S63. Verify the rationality of the determination method by comparing the uniaxial compressive strength and elastic modulus of the slurry and coal rock obtained in S62 with the uniaxial compressive strength and elastic modulus of the slurry and coal rock obtained in S2; S64. After the rationality of the determination method is verified in S63, the average indentation modulus of the slurry-coal binary interface transition zone obtained by the S51 test is substituted into the formula obtained in S61 to obtain the uniaxial compressive strength and elastic modulus of the slurry-coal binary interface transition zone.

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