Grouting rock structural surface shear strength calculation method considering high temperature effect
By establishing the relationship equation of peak shear strength of grouting rock structural surface after high temperature, the problem of the coupling effect of grout-rock interface not being considered in the existing technology at high temperature is solved, and the accurate prediction of mechanical behavior of grouting rock structural surface under high temperature environment is realized, which is suitable for reinforcement design in complex engineering scenarios.
Patent Information
- Application Number
- CN202511594332.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-03
- Publication Date
- 2026-02-03
AI Technical Summary
Existing methods for calculating the shear strength of grouting rock structures fail to effectively consider the coupling effect of the grout-rock interface under high temperature conditions. They cannot accurately quantify the temperature and cementation interface strength parameters, resulting in large prediction deviations after high temperatures and making them unsuitable for complex engineering scenarios.
By establishing the relationship equation of peak shear strength of ungrouted rock structural surface after high temperature treatment, and combining uniaxial compression test of grout and rock mass, shear test of grout smooth structural surface and porosity test of grout, the cement interface strength parameters are obtained, and the relationship equation of peak shear strength of grout rock structural surface after high temperature treatment is obtained by fitting with least squares method.
It accurately reflects the mechanical behavior of grouting rock structures under high-temperature conditions, improves the accuracy of shear strength prediction, and is applicable to the reinforcement design and stability evaluation of rock mass engineering projects such as fire, geothermal development, and nuclear waste disposal.
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Figure CN121453553A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of geotechnical engineering reinforcement and testing, in particular to a grouting rock structure surface shear strength calculation method considering high temperature effect. BACKGROUND
[0002] Rock structure surface often leads to significant shear mechanical property attenuation due to thermal damage, especially after underground engineering rock mass containing joints encounters fire high temperature and other sudden situations, which shows reduced peak shear strength and intensified creep deformation, directly threatening the long-term service performance of surrounding rock stability and supporting structure of underground engineering. Although the traditional ungrouted structure surface strength prediction model can describe the attenuation law under high temperature, it ignores the temperature sensitivity of the grouting reinforced interface, cannot accurately quantify the change of grouting body porosity, interface cementation strength attenuation and overall shear behavior, resulting in large prediction deviation.
[0003] The existing grouting rock structure surface shear strength calculation method is mostly based on uniaxial compression test, direct shear test and empirical formula under normal temperature conditions, which is difficult to fully consider the system of grouting body-rock mass interface coupling effect after high temperature; specifically, the existing method cannot effectively establish the quantitative relationship equation between temperature and cementation interface strength parameters, cannot reflect the role of roughness in the interface, in addition, the prediction formula has insufficient accuracy in high temperature decay prediction, and is difficult to be applied to complex engineering scenarios. SUMMARY
[0004] The present application provides a grouting rock structure surface shear strength calculation method considering high temperature effect to overcome the above problems.
[0005] In order to achieve the above purpose, the technical scheme of the present application is: A grouting rock structure surface shear strength calculation method considering high temperature effect, comprising: S1, establishing a peak shear strength relationship equation of ungrouted rock structure surface after high temperature effect according to the three-dimensional morphological characteristics of rock structure surface and high temperature influence parameters; S2, performing uniaxial compression experiment of grouting body and rock mass, grouting smooth structure surface shear experiment and grouting body porosity test, and obtaining cementation interface strength parameters of grouting rock structure surface, and then establishing a relationship equation between temperature and cementation interface strength parameters of grouting rock structure surface; the cementation interface strength parameters of grouting rock structure surface include grouting body rock wall compressive strength, rock wall compressive strength, cementation surface cohesion and cementation surface friction angle; S3, substituting the relationship equation between temperature and cementation interface strength parameters of grouting rock structure surface into the peak shear strength relationship equation of ungrouted rock structure surface after high temperature effect, to obtain the peak shear strength relationship equation of grouting rock structure surface after high temperature effect; S4, carry out the shearing experiment and the three-dimensional scanning test of the structure surface after high temperature post grouting, and obtain the roughness parameter and the shearing strength of the grouting structure surface; according to the roughness parameter and the shearing strength of the grouting structure surface, the undetermined parameter in the peak shearing strength relation equation of the grouting rock structure surface after high temperature is fitted by the least square method, and the peak shearing strength relation equation of the grouting rock structure surface after high temperature is obtained, which is used for predicting the peak shearing strength of the grouting rock structure surface after high temperature.
[0006] Further, the specific steps for establishing the peak shearing strength relation equation of the ungrouting rock structure surface after high temperature include: According to the three-dimensional morphological characteristics of the structure surface and the influence factors of high temperature, the peak shearing strength relation equation of the ungrouting rock structure surface after high temperature is established; wherein the three-dimensional morphological characteristics of the structure surface include the peak shearing strength, the normal stress, the roughness, the basic friction angle of the rock structure surface and the effective expansion angle of the rock structure surface; the influence factors of high temperature are the action temperature, the basic friction angle of the rock structure surface after high temperature and the effective expansion angle of the rock structure surface after high temperature; The peak shearing strength relation equation of the ungrouting rock structure surface after high temperature is expressed as: (1) In the formula, is the peak shearing strength; is the normal stress; is the basic friction angle of the rock structure surface after high temperature; is the effective expansion angle of the rock structure surface after high temperature, that is, the expansion angle of the uneven structure surface which contributes to the shearing resistance; Wherein, the expression of the effective expansion angle after high temperature is: (2) In the formula, is the rock wall compression strength of the rock structure surface after high temperature; T is the action temperature; is the maximum apparent inclination angle of the convex in the shearing direction; C is the roughness parameter; is the initial effective expansion angle; is the reduction coefficient of the initial effective expansion angle after high temperature; Substitute formula (2) into formula (1), and the peak shearing strength relation equation of the ungrouting rock structure surface after high temperature is expressed as: (3).
[0007] Further, the specific steps for establishing the relation equation of the temperature and the grouting rock structure surface cementation interface strength parameter include: S31, obtaining the rock wall compressive strength of the grouting body and the rock wall compressive strength of the rock according to the stress-strain curves of the uniaxial compression experiment of the grouting body and the rock; S32, obtaining the cohesion of the cementation surface of the grouting rock structure surface according to the grouting smooth structure surface shearing experiment; S33, obtaining the friction angle of the cementation surface according to the porosity test of the grouting body; S34, fitting the relationship between the rock wall compressive strength of the grouting body and the rock wall compressive strength of the rock after different high temperatures, and establishing the relationship equation between the rock wall compressive strength of the grouting body and the rock wall compressive strength of the rock after different high temperatures and temperature, the expression is: (4) (5) In the formula, is the rock wall compressive strength of the grouting body after high temperature; is the rock wall compressive strength of the rock after high temperature; is the rock wall compressive strength of the grouting body at room temperature; is the determination coefficient; S35, establishing the relationship equation between the cohesion of the rough structure surface of the grouting rock and temperature after different high temperatures, the expression is: (6) In the formula, is the cohesion of the rough structure surface after high temperature; is the cohesion of the sandstone-cementation interface after high temperature; is the fitting parameter; C is the roughness parameter; indicates the maximum inclination angle of the structure surface; S36, establishing the relationship equation between the friction angle of the cementation surface and temperature, the expression is: (7) (8) (9) In the formula, is the friction angle of the cementation surface after high temperature; is the friction angle of the cementation surface at room temperature; , is the grouting body and rock interface friction characteristic correlation value; , , , is the fitting parameter; is the inflection point temperature.
[0008] Further, the expression of the peak shear strength relation equation of the grouting rock structure surface after high temperature action is: (10) In the formula, is the equivalent compressive strength; is a grouting filling correlation coefficient; is the maximum apparent inclination angle of the protrusion along the shear direction; wherein the expression of the equivalent compressive strength is: (11) In the formula, is the equivalent compressive strength; is the fitting parameter of the equivalent compressive strength.
[0009] Further, the structure surface morphology three-dimensional scanning test is used to obtain the roughness parameter, and the specific steps include: S51, a three-dimensional model of the structure surface is established by three-dimensional scanning of the rock structure surface, and the three-dimensional model is measured, the maximum potential contact area ratio of the roughness and the maximum apparent inclination angle of the protrusion along the shear direction are obtained according to the point cloud coordinate data obtained by the three-dimensional scanning; S52, the roughness parameter for describing the apparent inclination angle distribution is defined according to the maximum potential contact area ratio and the maximum apparent inclination angle of the protrusion along the shear direction, and the expression is: (12) In the formula, is the contact area ratio; is the maximum potential contact area ratio; is the apparent inclination angle; S53, the three-dimensional model of the structure surface is divided into triangular elements, and the apparent inclination angle of each triangular element is calculated, and the expression is: (13) (14) (15) In the formula, is the inclination angle of the triangular element; is the shear direction; is the outer normal vector of the triangle; is the normal vector of the shear surface; is the projection vector of ; is the angle between and ; S54, the roughness parameter is obtained according to formula (12) to formula (15).
[0010] Beneficial effects: the shear strength calculation method of the grouting rock structure surface considering the high temperature effect, the peak shear strength relation equation of the un-grouting rock structure surface after the high temperature is established, the strength parameters of the grouting body and the rock body cementation interface are introduced, the high temperature effect, the three-dimensional morphological characteristics of the structure surface and the grouting reinforcement effect are combined systematically, the grouting rock structure surface shear strength calculation method reflecting the temperature influence is constructed, and the mechanical behavior of the grouting rock structure surface under the high temperature environment can be more accurately reflected; The strength parameters of the grouting body and the rock body cementation interface are obtained through experiments, and a quantitative relationship between the strength parameters and the temperature is established, the multi-scale parameter coupling from the material level to the structure surface level is realized, the physical meaning of the finally obtained peak shear strength relation equation is clear, the parameter determination process is scientific, and the prediction accuracy of the shear strength of the grouting structure surface after the high temperature is significantly improved; The key parameters are determined by combining experiments and theories, the process is clear, the operability is strong, and the grouting reinforcement design and stability evaluation of the rock mass engineering which has experienced the high temperature effect (such as fire, geothermal development, nuclear waste disposal and the like) can be directly served. BRIEF DESCRIPTION OF DRAWINGS
[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, a brief introduction will be given to the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.
[0012] Figure 1 It is the flow chart of the shear strength calculation method of the present application; Figure 2a It is the R1 topographic map reconstructed after the three-dimensional scanning of the rock structure surface in the embodiment of the present application; Figure 2b It is the R2 topographic map reconstructed after the three-dimensional scanning of the rock structure surface in the embodiment of the present application; Figure 2c It is the R3 topographic map reconstructed after the three-dimensional scanning of the rock structure surface in the embodiment of the present application; Figure 3 It is the relationship between the temperature and the yellow sandstone rock wall strength parameters obtained in the embodiment of the present application; Figure 4 It is the relationship between the temperature and the grouting body rock wall strength parameters obtained in the embodiment of the present application; Figure 5 It is the grouting smooth structure surface shear test method proposed in the embodiment of the present application; Figure 6 It is the relationship between the temperature and the interface cohesion obtained in the embodiment of the present application; Figure 7This is the relationship between temperature and interfacial friction angle obtained in the embodiments of the present invention; Figure 8 This is a comparison diagram of the experimental values obtained in the embodiments of the present invention and the predicted peak shear strength values of the present invention. Detailed Implementation
[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0014] This embodiment provides a method for calculating the shear strength of grouted rock structural surfaces considering high-temperature effects, such as... Figure 1 As shown, it includes: S1. Based on the three-dimensional morphological characteristics of the rock structure surface and the high temperature influence parameters, establish the relationship equation of peak shear strength of the ungrouted rock structure surface after high temperature action; S2. Conduct uniaxial compression tests on the grouting body and rock mass, shear tests on the smooth grouting structural surface, and porosity tests on the grouting body to obtain the cementation interface strength parameters of the grouting rock structural surface. Then, establish the relationship equation between temperature and the cementation interface strength parameters of the grouting rock structural surface. The cementation interface strength parameters of the grouting rock structural surface include the compressive strength of the grouting body rock wall, the compressive strength of the rock wall, the cohesion of the cementation surface, and the friction angle of the cementation surface. S3. Substitute the equation relating temperature to the strength parameters of the cemented interface of the grouted rock structure into the equation relating the peak shear strength of the ungrouted rock structure after high temperature action to obtain the equation relating the peak shear strength of the grouted rock structure after high temperature action. S4. Conduct shear tests and three-dimensional scanning tests of the grouting surface after high temperature to obtain the roughness parameters and shear strength of the grouting surface. Based on the roughness parameters and shear strength of the grouting surface, fit the undetermined parameters in the peak shear strength relationship equation of the grouting rock surface after high temperature using the least squares method to obtain the peak shear strength relationship equation of the grouting rock surface after high temperature with determined parameters, which is used to predict the peak shear strength of the grouting rock surface after high temperature.
[0015] Specifically, in this embodiment, the high temperature is 200°C or above.
[0016] Preferably, the specific steps for establishing the relationship equation between the peak shear strength of ungrouted rock structural surfaces after high-temperature treatment include: According to the three-dimensional morphological characteristics of the structural plane and the influencing factors of high temperature, a peak shear strength relationship equation of the ungrouted rock structural plane after high temperature is established; the three-dimensional morphological characteristics of the structural plane include peak shear strength, normal stress, roughness, basic friction angle of the rock structural plane and effective expansion angle of the rock structural plane; the influencing factors of high temperature are action temperature, basic friction angle of the rock structural plane after high temperature and effective expansion angle of the rock structural plane after high temperature; The peak shear strength relationship equation of the ungrouted rock structural plane after high temperature is expressed as: (1) In the formula, is the peak shear strength; is the normal stress; is the basic friction angle of the rock structural plane after high temperature; is the effective expansion angle of the rock structural plane after high temperature, that is, the expansion angle of the unevenness of the structural plane contributing to the shear resistance; The expression of the effective expansion angle after high temperature is: (2) In the formula, is the rock wall compressive strength of the rock structural plane after high temperature; T is the action temperature; is the maximum apparent inclination angle of the protrusion in the shear direction; C is the roughness parameter; is the initial effective expansion angle; is the reduction coefficient of the initial effective expansion angle after high temperature; Substitute equation (2) into equation (1), and the peak shear strength relationship equation of the ungrouted rock structural plane after high temperature is expressed as: (3).
[0017] In specific embodiments, the highest temperature of various experiments and tests is set to 800℃; the sample is placed in a high-temperature furnace for heating, and the target temperature is set to 200℃, 400℃, 600℃ and 800℃ respectively, and the heating rate is set to 5℃ / min to avoid the influence of thermal shock; when the target temperature is reached, the sample is kept for 4h to make the sample completely and uniformly heated, and then the heated sample is naturally cooled under normal temperature conditions; The surfaces of three selected sandstone structural planes (R1, R2 and R3) are measured and reconstructed by using a rock structural plane three-dimensional morphology laser tester, and the modeling is as Figures 2a to 2cThe grouting smooth structural surface shear test and the grouting body porosity test are carried out on the samples after different high-temperature treatments, and the data are recorded; the shear test is carried out on the samples after the high-temperature treatment, the normal stress is set to 5, 10 and 15 MPa, the shear test is stopped after the tangential displacement reaches 5 mm, and the loading rate is 0.01 mm / s; and the shear test is carried out on the structural surface samples after the high-temperature treatment; According to the heating and shear test results, the structural surface roughness parameters, the cementation surface cohesion of the grouting rock structural surface after different high temperatures, the cementation surface friction angle of the grouting rock structural surface after different high temperatures and the structural surface shear strength of the yellow sandstone after different high temperatures are obtained. The high-temperature equipment of the embodiment adopts an SX2-8-10 box-type resistance furnace, the temperature of the equipment can reach 1200℃ at most, and the temperature error is within 1℃.
[0018] Preferably, the specific steps of establishing the relationship equation between the temperature and the cementation interface strength parameters of the grouting rock structural surface include: S31, according to the stress-strain curves of the grouting body and the rock mass uniaxial compression experiment, the rock wall compressive strength of the grouting body and the rock wall compressive strength of the rock after different high temperatures are obtained, as shown in Figure 3 and Figure 4 ; S32, according to the grouting smooth structural surface shear test, the cementation surface cohesion of the grouting rock structural surface after different high temperatures is obtained. S33, according to the grouting body porosity test, the cementation surface friction angle is obtained. Specifically, the grouting body and the rock mass uniaxial compression experiment and the grouting body porosity test are prior art, the grouting smooth structural surface shear test can be derived by the prior art; the rock wall compressive strength of the grouting body and the rock wall compressive strength of the rock after different high temperatures, the cementation surface cohesion of the grouting rock structural surface after different high temperatures, and the cementation surface friction angle obtained according to the grouting body porosity test are all prior art for those skilled in the art, and will not be described in detail here. S34, the relationship fitting is carried out on the rock wall compressive strength of the grouting body and the rock wall compressive strength of the rock after different high temperatures through the temperature change, the relationship equation between the rock wall compressive strength of the grouting body and the rock wall compressive strength of the rock after different high temperatures and the temperature is established, and the expression is: (4) (5) In the formula, is the rock wall compressive strength of the grouting body after high temperature; is the rock wall compressive strength of the rock after high temperature; is the rock wall compressive strength of the grouting body at room temperature; is a determination coefficient; S35, establish the relationship equation between the cohesion of the rough structure surface of the rock after high temperature grouting and the temperature by the cohesion of the cementation surface of the rough structure surface of the rock after different high temperature grouting, and the expression is: (6) In the formula, The cohesion of the rough structure surface after high temperature; The cohesion of the sandstone-cementation interface after high temperature; The fitting parameter; C The roughness parameter; Indicates the maximum inclination of the structure surface; As Figure 5 shown, the embodiment provides a grouting structure surface shear test method which cannot obtain the cohesion C 0 of the direct shear test of stress; 28 days after grouting and solidification, the load is applied to the sample, and the load is mainly applied to the sandstone sample; compared with the traditional shear test method, the normal stress is zero, the structure surface is smooth, and the test result is mainly controlled by the cohesion C 0 of the cementation interface between the rock and the grouting body (excluding the influence of roughness); The smooth grouting structure surface after high temperature is subjected to the direct shear test without stress, the cohesion of the sandstone-cementation interface after high temperature is obtained, the result of the cohesion of the sandstone-cementation interface after high temperature is as Figure 6 shown, and the cohesion of the sandstone-cementation interface after high temperature is fitted with the temperature to obtain the cohesion of the sandstone-cementation interface after high temperature determined by the fitting parameter, and the expression is: (7); S36, establish the relationship equation between the friction angle of the cementation surface and the temperature by the friction angle of the cementation surface, and the expression is: (8) (9) (10) In the formula, The friction angle of the cementation surface after high temperature; The friction angle of the cementation surface at room temperature; , The interface friction characteristic value of the grouting body and the rock, which mainly reflects the influence of the physical and chemical properties of the interface material and the bonding strength on the change of the friction angle; , , , The fitting parameter; The inflection point temperature, which indicates that when the temperature approaches this value, the trend of the change of the friction angle will change significantly; In specific embodiments, the porosity of the cementing interface is typically 10-20% higher than that of the main slurry; assuming the porosity of the cementing interface is 15% higher than that of the main slurry; since the strength of hardened cement increases with the porosity of the cementing interface ( w / c The value decreases as the number of elements increases, therefore, in cases where this becomes unreasonable, we can assume that this relationship is linear and take... φ 0.5 =39° and φ 1.1 =29°; when w / c The estimated internal friction angles of the cemented interface at different temperatures are as follows: (The values are 1.5:1, 1:1, and 0.5:1 respectively). Figure 7 As shown; therefore, the equation relating the friction angle of the bonded surface to temperature can be expressed as follows: (11) Among them, the inflection point temperature It is set to 299.13°.
[0019] Preferably, the expression for the equation relating the peak shear strength of the grouting rock structure after high-temperature treatment is as follows: (12) In the formula, Equivalent compressive strength; For grouting and filling correlation coefficients; The expression for the equivalent compressive strength is: (13) In the formula, for Equivalent compressive strength fitting parameters.
[0020] Specifically, after grouting the ungrouted rock structural surface, the equation relating the peak shear strength of the ungrouted rock structural surface after high temperature is changed due to grouting. The cohesion of the rough structural surface of the grouted rock and the compressive strength of the grout wall and the rock wall after different high temperatures are substituted into the equation relating the peak shear strength of the ungrouted rock structural surface after high temperature, and the friction angle of the cemented surface is replaced with the basic friction angle of the rock structural surface.
[0021] Specifically, the roughness parameters and shear strength of the grouting structure are obtained from the shear test of the grouting structure after high temperature and the three-dimensional scanning test of the structure morphology. Based on the roughness parameters and shear strength of the grouting structure, the least squares method is used to fit the formula of equation (12) to obtain the fitting values of fitting parameters k1, k2 and k3. These values are then substituted into equation (12) to obtain the relationship equation of peak shear strength of the grouting rock structure after high temperature with the parameters determined. The results of the shear experiment of the high-temperature post-grouting structural surface are compared with the results predicted by the peak shear strength relationship equation of the high-temperature post-grouting rock structural surface, and the comparison results are as shown in Figure 8 .
[0022] Preferably, the structural surface topography three-dimensional scanning test is used to obtain the roughness parameters, and the specific steps include: S51, a three-dimensional model of the structural surface is established by three-dimensional scanning of the rock structural surface, and the three-dimensional model is measured, the maximum potential contact area ratio of the roughness and the maximum apparent inclination of the protrusion along the shear direction are obtained according to the point cloud coordinate data obtained by the three-dimensional scanning; S52, the roughness parameters for describing the apparent inclination distribution are defined according to the maximum potential contact area ratio and the maximum apparent inclination of the protrusion along the shear direction, and the expression is: (12) In the formula, is the contact area ratio; is the maximum potential contact area ratio; is the apparent inclination; S53, the three-dimensional model of the structural surface is divided into triangular elements, and the apparent inclination of each triangular element is calculated, and the expression is: (13) (14) (15) In the formula, is the inclination of the triangular element; is the shear direction; is the outer normal vector of the triangle; is the normal vector of the shear surface; is the projection vector of ; is the angle between and ; S54, the roughness parameters are obtained according to the formula (12) to the formula (15).
[0023] Specifically, the shear experiment of the high-temperature post-grouting structural surface includes the following specific steps: First, set the target temperature, place it in the heating equipment, heat to the target temperature, and keep it constant for 4h, and then naturally cool down; Second, use the shear equipment to shear the sample, apply the normal stress, the loading rate is 0.01mm / s, and shear the structural surface sample after high-temperature treatment; Finally, the stress-displacement curve of the shear test is obtained, and the shear strength of the grouting rock structural surface sample after high temperature is obtained.
[0024] In specific embodiments, the results of the shear test and the three-dimensional scanning test of the high-temperature post-grouting structural surface are shown in Table 1.
[0025] Table 1 Roughness parameters and shear mechanical parameters of each roughness sample
[0026] The present application has the following beneficial effects: the present application is a grouting rock structural surface shear strength calculation method considering high temperature effect, by establishing the peak shear strength relationship equation of the un-grouting rock structural surface after high temperature, and introducing the strength parameters of the grouting body and rock mass cementation interface, systematically combining high temperature effect, structural surface three-dimensional morphological characteristics and grouting reinforcement effect, a grouting rock structural surface shear strength calculation method reflecting temperature influence is constructed, which can more accurately reflect the mechanical behavior of grouting rock structural surface under high temperature environment; The strength parameters of the grouting body and rock mass cementation interface obtained by experiment are combined with temperature to establish a quantitative relationship, realizing multi-scale parameter coupling from the material level to the structural surface level, the peak shear strength relationship equation obtained finally has clear physical meaning, the parameter determination process is scientific, and the prediction accuracy of the shear strength of the grouting structural surface after high temperature is significantly improved; The key parameters are determined by combining experiment and theory, the process is clear and operable, and can directly serve the grouting reinforcement design and stability evaluation of rock mass engineering that has experienced high temperature effect (such as fire, geothermal development, nuclear waste disposal, etc.).
[0027] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A method for calculating the shear strength of a grouting rock structure surface considering the effect of high temperature, characterized in that, The application relates to a method for predicting the peak shear strength of a grouting rock structure surface after high-temperature action. The method comprises the following steps: S1, establishing a peak shear strength relation equation of a non-grouting rock structure surface after high-temperature action according to the three-dimensional morphological characteristics of the rock structure surface and high-temperature influence parameters; S2, performing uniaxial compression experiments on grouting bodies and rock bodies, performing grouting smooth structure surface shearing experiments, and testing the porosity of the grouting bodies, and obtaining grouting rock structure surface cementation interface strength parameters, and then establishing a relation equation of temperature and the grouting rock structure surface cementation interface strength parameters; the grouting rock structure surface cementation interface strength parameters comprise grouting body rock wall compressive strength, rock wall compressive strength, cementation surface cohesion and cementation surface friction angle; S3, substituting the relation equation of temperature and the grouting rock structure surface cementation interface strength parameters into the peak shear strength relation equation of the non-grouting rock structure surface after high-temperature action to obtain a peak shear strength relation equation of the grouting rock structure surface after high-temperature action; 2. The method for calculating the shearing strength of grouting rock structure surface considering high temperature effect according to claim 1, characterized in that, S4, performing shearing experiments on the grouting structure surface after high-temperature action and three-dimensional scanning tests on the structure surface appearance to obtain roughness parameters and the shearing strength of the grouting structure surface; according to the roughness parameters and the shearing strength of the grouting structure surface, the least square method is used to fit the undetermined parameters in the peak shear strength relation equation of the grouting rock structure surface after high-temperature action to obtain the peak shear strength relation equation of the grouting rock structure surface after high-temperature action with the parameters determined, which is used for predicting the peak shear strength of the grouting rock structure surface after high-temperature action. The specific steps for establishing the peak shear strength relation equation of the non-grouting rock structure surface after high-temperature action comprise the following steps: According to the three-dimensional morphological characteristics of the structure surface and the influence factors of high temperature, a peak shear strength relation equation of a non-grouting rock structure surface after high-temperature action is established; wherein the three-dimensional morphological characteristics of the structure surface comprise peak shear strength, normal stress, roughness, rock structure surface basic friction angle and rock structure surface effective expansion angle; the influence factors of high temperature are action temperature, rock structure surface basic friction angle after high-temperature action and rock structure surface effective expansion angle after high-temperature action; （1） wherein is the peak shear strength; is the normal stress; is the basic friction angle of rock structural plane after high temperature action; is the effective dilation angle of rock structural plane after high temperature action, i.e. the dilation angle of the unevenness of the structural plane contributing to the shear resistance; The expression of the peak shear strength relation equation of the non-grouting rock structure surface after high-temperature action is as follows: （2） wherein is the compressive strength of the rock mass structure surface wall after high temperature action; T is the action temperature; is the maximum apparent inclination of the protrusion in the shear direction; C is the roughness parameter; is the initial effective dilation angle; is the reduction factor of the initial effective dilation angle after high temperature action; The expression of the effective expansion angle after high-temperature action is as follows: （3）。 3. The method for calculating the shearing strength of grouting rock structure surface considering high temperature effect according to claim 1, characterized in that, The expression of the peak shear strength relation equation of the non-grouting rock structure surface after high-temperature action is as follows: The specific steps for establishing the relation equation of temperature and the grouting rock structure surface cementation interface strength parameters comprise the following steps: S31, obtaining grouting body rock wall compressive strength and rock wall compressive strength after different high-temperature actions according to the stress-strain curves of the uniaxial compression experiments on the grouting bodies and the rock bodies; S32, obtaining grouting rock structure surface cementation surface cohesion after different high-temperature actions according to the grouting smooth structure surface shearing experiments; S33, obtaining the cementation surface friction angle according to the porosity test of the grouting bodies; S34, fitting the relation of the grouting body rock wall compressive strength and the rock wall compressive strength after different high-temperature actions through temperature change, and establishing a relation equation between the grouting body rock wall compressive strength and the rock wall compressive strength after different high-temperature actions and temperature, and the expression is as follows: （4） （5） In the formula, is the compressive strength of the high-temperature post-grouting body rock wall; is the compressive strength of the high-temperature post-rock wall; is the compressive strength of the grouting body rock wall at room temperature; is the determination coefficient; S35, establish a relationship equation between the cohesion of the rough structure surface of the grouted rock after different high temperature and the temperature through the cohesion of the cemented surface of the rough structure surface of the grouted rock after different high temperature, and the expression is: （6） wherein cohesion of the rough surface after high temperature; cohesion of the sandstone-cement interface after high temperature; is a fitting parameter; C is a roughness parameter; denotes the maximum inclination of the structural plane; S36, establish a relationship equation between the friction angle of the cemented surface and the temperature through the friction angle of the cemented surface, and the expression is: （7） （8） （9） wherein is the high-temperature bond face friction angle; is the room-temperature bond face friction angle; , is the grout-rock interface friction characteristic value; , , , is a fitting parameter; is the inflection point temperature.
4. The method for calculating the shearing strength of grouting rock structure surface considering high temperature effect according to claim 1, characterized in that, The expression of the relationship equation of the peak shear strength of the grouted rock structure surface after high temperature is: （10） In the formula, is the equivalent compressive strength; is the grouting filling related coefficient; is the maximum apparent inclination angle of the protrusion in the shear direction; Wherein, the expression of the equivalent compressive strength is: （11） In the formula, is Equivalent compressive strength fitting parameters.
5. The method for calculating the shearing strength of grouting rock structure surface considering high temperature effect according to claim 1, characterized in that, The structure surface morphology three-dimensional scanning test is used for obtaining the roughness parameters, and the specific steps include: S51, establish a three-dimensional model of the structure surface and measure it by three-dimensional scanning of the rock structure surface, obtain the maximum potential contact area ratio of the roughness and the maximum apparent inclination of the protrusion along the shear direction according to the point cloud coordinate data obtained by three-dimensional scanning; S52, define the roughness parameters for describing the apparent inclination distribution according to the maximum potential contact area ratio and the maximum apparent inclination of the protrusion along the shear direction, and the expression is: （12） wherein is the contact area ratio; is the maximum potential contact area ratio; is the apparent tilt angle; S53, divide the three-dimensional model of the structure surface into triangular elements, calculate the apparent inclination of each triangular element, and the expression is: （13） （14） （15） wherein is the angle of inclination of the triangular cell; is the shear direction; is the outward normal vector of the triangular cell; is the normal vector of the shear plane; is the projection vector of is the angle between and is the angle between S54, obtain the roughness parameters according to formula (12) to formula (15).