A method for establishing a three-dimensional mechanical model of deep hard rock dynamic disturbance

Abstract

The application provides a kind of deep hard rock dynamic disturbance three-dimensional mechanical model establishing method, it is related to rock mechanics performance and engineering technical field.The method includes: the deep hard rock of being taken from deep certain tunnel engineering carries out true triaxial test under no dynamic disturbance and true triaxial test under dynamic disturbance, records the whole process test data of mechanical behavior of each test;By comparing all the deep hard rock after test to determine the failure mode of deep hard rock under different dynamic disturbance;Based on the whole process test data of mechanical behavior of deep hard rock under dynamic disturbance and the failure mode of deep hard rock under different dynamic disturbance, by constructing the mechanical model of deep hard rock under dynamic disturbance true triaxial condition, the parameter evolution model of cohesion and internal friction angle under dynamic disturbance true triaxial condition is determined.The application can predict the mechanical behavior of hard rock under the influence of multi-source dynamic disturbance, and provide basis for the stability evaluation of surrounding rock in the construction process of deep hard rock area.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rock mechanical properties and engineering technology, and particularly relates to a method for establishing a deep hard rock dynamic disturbance three-dimensional mechanical model. BACKGROUND

[0002] In deep hard rock tunnels, the surrounding rock is in a true three-dimensional high stress environment, and under the influence of the advancing tunnel face and vehicle operation, the surrounding rock is often subjected to multi-source dynamic disturbance, such as drilling and blasting, TBM method, seismic wave, rock burst stress wave and train running vibration wave. These dynamic disturbances will have a significant stress wave propagation and energy dissipation effect on the hard rock, making the mechanical behavior of the hard rock under dynamic disturbance complex. The traditional static model cannot accurately describe the dynamic mechanical response of the deep hard rock, and is even limited to two-dimensional models or simplified assumptions, and cannot fully reflect the true mechanical behavior of the hard rock in a three-dimensional high stress space.

[0003] In order to accurately analyze and predict the response of the hard rock under dynamic disturbance, a new method for establishing a three-dimensional mechanical model is needed, which can comprehensively consider the nonlinearity, anisotropy of the hard rock and the influence of dynamic disturbance, and reflect the three-dimensional mechanical model of the deformation and failure of the hard rock under dynamic load. SUMMARY

[0004] In view of the above deficiencies of the prior art, the present application proposes a method for establishing a deep hard rock dynamic disturbance three-dimensional mechanical model by analyzing the rock failure and deformation characteristics under different dynamic disturbance factors, aiming to predict the mechanical behavior of the hard rock under the influence of multi-source dynamic disturbance and provide a basis for the stability evaluation of the surrounding rock in the construction process of the deep hard rock area.

[0005] The present application proposes a method for establishing a deep hard rock dynamic disturbance three-dimensional mechanical model, which includes the following processes:

[0006] Performing a true triaxial test on the deep hard rock taken from the deep tunnel engineering without dynamic disturbance, and recording the whole process test data of the mechanical behavior of the deep hard rock under no dynamic disturbance;

[0007] Based on the whole process test data of the mechanical behavior of the deep hard rock under no dynamic disturbance, performing a true triaxial test on the deep hard rock taken from the deep tunnel engineering under dynamic disturbance, and recording the whole process test data of the mechanical behavior of the deep hard rock under dynamic disturbance;

[0008] For the deep hard rock after the true triaxial test without dynamic disturbance and the deep hard rock after the true triaxial test under dynamic disturbance, the failure mode of the deep hard rock under different dynamic disturbances is determined by comparing and analyzing the failure mode of the deep hard rock after each test;

[0009] Based on the whole process test data of the mechanical behavior of deep hard rock under dynamic disturbance and the failure mode of deep hard rock under different dynamic disturbances, a mechanical model of deep hard rock under dynamic disturbance true triaxial condition is constructed.

[0010] Based on the mechanical model of deep hard rock under dynamic disturbance true triaxial condition, the cohesion and the internal friction angle under the parameter evolution model of dynamic disturbance true triaxial condition are determined.

[0011] Further, the specific content of the true triaxial test of deep hard rock taken from deep tunnel engineering under no dynamic disturbance and recording the whole process test data of the mechanical behavior of deep hard rock under no dynamic disturbance is as follows:

[0012] For deep tunnel engineering, the stress data of surrounding rock at different distances from the working face are obtained; wherein the stress data of surrounding rock include: intermediate principal stress and minimum principal stress .

[0013] According to the obtained stress data of surrounding rock, the stress path is designed, and the true triaxial test of deep hard rock under no dynamic disturbance is carried out by using dynamic disturbance true triaxial testing machine according to the designed stress path, to obtain the peak strength of deep hard rock under no dynamic disturbance, and record the whole process test data of the mechanical behavior of deep hard rock under no dynamic disturbance, and then draw the full stress-strain curve of deep hard rock under no dynamic disturbance.

[0014] The whole process test data of the mechanical behavior of deep hard rock under true triaxial action are the stress values and strain values of deep hard rock in three directions under the change of principal stress.

[0015] Further, the deep hard rock used in the true triaxial stress path test of hard rock and the dynamic disturbance true triaxial test of deep hard rock are standard rock samples cut from the same rock, and all the standard rock samples are detected for uniformity before the test.

[0016] Further, the specific method of carrying out the true triaxial test of deep hard rock taken from deep tunnel engineering under dynamic disturbance based on the whole process test data of the mechanical behavior of deep hard rock under no dynamic disturbance and recording the whole process test data of the mechanical behavior of deep hard rock under dynamic disturbance is as follows:

[0017] According to the peak strength of deep hard rock under no dynamic disturbance, a plurality of different disturbance timings are set.

[0018] Obtaining a disturbance wave signal of a tunnel engineering site and generating a disturbance wave time-frequency curve, extracting a frequency range of the disturbance wave from the disturbance wave time-frequency curve, and determining a plurality of disturbance frequencies through Fourier transform based on the disturbance wave signal of the tunnel engineering site and the frequency range of the disturbance wave ;

[0019] Obtaining rock wave velocity, rock density and surrounding rock particle velocity of the tunnel engineering site, and calculating a plurality of disturbance amplitudes by using the measured rock wave velocity, rock density and surrounding rock particle velocity ;

[0020] Generating all possible dynamic disturbance conditions by traversing all combinations of the plurality of disturbance frequencies and the plurality of disturbance amplitudes ;

[0021] Based on the stress path designed in the true triaxial test without dynamic disturbance, the true triaxial test of the deep hard rock under dynamic disturbance is carried out according to different dynamic disturbance conditions, and dynamic disturbance is applied at a plurality of disturbance times set during the test to obtain the peak strength of the deep hard rock under dynamic disturbance , and record the mechanical behavior whole process test data of the deep hard rock under dynamic disturbance, and further draw the full stress-strain curve of the deep hard rock under dynamic disturbance.

[0022] The mechanical behavior whole process test data of the deep hard rock under dynamic disturbance includes: disturbance time, disturbance times, strength value, stress value and strain value of the deep hard rock under dynamic disturbance.

[0023] Further, by comparing and analyzing the failure mode of the deep hard rock after each test, the specific content of the failure mode of the deep hard rock under different dynamic disturbances is determined

[0024] For any deep hard rock after the true triaxial test without dynamic disturbance or the true triaxial test under dynamic disturbance, the crack type of the deep hard rock is determined, and the crack failure angle of the deep hard rock is measured.

[0025] The failure surface of the deep hard rock is 3D laser scanned to obtain the coordinates of each point in the failure surface based on the horizontal plane, and the JRC value of the failure surface is calculated by using the coordinates of each point based on the horizontal plane, and the failure mode of the deep hard rock under the macroscopic angle is determined to be one of shear failure, tensile failure or mixed failure according to the JRC value of the failure surface.

[0026] Based on the crack type, crack failure angle and failure mode of the deep hard rock, a representative area is selected in the failure surface of the deep hard rock, and a slice is taken from the failure surface according to the selected representative area, the slice is subjected to SEM electron microscope scanning, the micro characteristics of the failure surface are observed and recorded, and the failure mode of the deep hard rock under the micro angle is determined to be one of shear failure, tensile failure or mixed failure according to the micro characteristics of the failure surface;

[0027] The failure mode of the deep hard rock under the macro angle is compared with the failure mode of the deep hard rock under the micro angle, if they are consistent, the failure mode of the deep hard rock is determined, if they are not consistent, the failure mode of the deep hard rock is re-determined in combination with the JRC value of the failure surface and the micro characteristics of the failure surface;

[0028] The failure mode of the deep hard rock under different dynamic disturbances is determined by comparing the failure mode of the deep hard rock after the true triaxial test under the non-dynamic disturbance with the failure modes of the deep hard rock after the true triaxial tests under all dynamic disturbances.

[0029] Further, the specific content of constructing the mechanical model of the deep hard rock under the dynamic disturbance true triaxial condition based on the whole process test data of the mechanical behavior of the deep hard rock under the dynamic disturbance and the failure modes of the deep hard rock under different dynamic disturbances is:

[0030] Based on the whole process test data of the mechanical behavior of the deep hard rock under the dynamic disturbance and the failure modes of the deep hard rock under different dynamic disturbances, the variation law of the peak strength of the deep hard rock under different dynamic disturbance conditions and the deformation amount of the deep hard rock in each disturbance stage under different dynamic disturbance conditions are obtained.

[0031] According to the whole stress-strain curve of the deep hard rock under the dynamic disturbance, the mechanical behavior of the deep hard rock under the dynamic disturbance is divided into three disturbance stages, which are: elastic deformation stage, plastic deformation stage and irreversible deformation stage.

[0032] Based on the whole process test data of the mechanical behavior of the deep hard rock under the dynamic disturbance, the elastic deformation amount, plastic deformation amount and dynamic disturbance irreversible deformation amount under the dynamic disturbance are calculated.

[0033] According to the elastic deformation amount, plastic deformation amount and dynamic disturbance irreversible deformation amount of the deep hard rock under the dynamic disturbance, a mechanical model of the deep hard rock under the dynamic disturbance true triaxial condition is constructed.

[0034] Further, the construction method of the mechanical model of the deep hard rock under the dynamic disturbance true triaxial condition is:

[0035] ​Based on the elastoplastic constitutive relation, the incremental stress-strain relation of deep hard rock under dynamic disturbance is established according to the elastic deformation, plastic deformation and irreversible deformation under dynamic disturbance, and is expressed as:

[0036]

[0037]

[0038] wherein represents the stress increment tensor; represents the strain increment tensor; is the anisotropic elastic stiffness tensor based on Young's modulus , Poisson's ratio and plastic history ; the plastic history is taken as an internal variable, and represents the inelastic irreversible deformation according to the second law of thermodynamics; is the dynamic disturbance irrecoverable strain increment of deep hard rock under dynamic disturbance true triaxial condition; represents the plastic strain increment; represents the brittleness index;

[0039] For the incremental stress-strain relation of deep hard rock, the plastic strain increment of deep hard rock under dynamic disturbance true triaxial condition is determined according to the plastic flow rule ; at the same time, the dynamic disturbance irrecoverable strain increment of deep hard rock under dynamic disturbance true triaxial condition is determined .

[0040] Further, the dynamic disturbance damage factor is determined according to the whole process test data of the mechanical behavior of deep hard rock under dynamic disturbance.

[0041] Further, the dynamic disturbance irrecoverable strain increment of deep hard rock under dynamic disturbance true triaxial condition is expressed as:

[0042]

[0043] wherein is the average strain fitting generated by single disturbance for different amplitude disturbances under different stress states; is the dynamic disturbance multiplier; is the disturbance time.

[0044] Further, the dynamic disturbance damage factor is:

[0045]

[0046] wherein is the dynamic disturbance damage factor;​​​​ and are material parameters, which are obtained by the test data of the whole process of mechanical behavior of deep hard rock under dynamic disturbance; represents the critical stress of dynamic disturbance; is the disturbance times.

[0047] Further, the mechanical model of deep hard rock under dynamic disturbance true triaxial condition is used to determine the cohesion and the internal friction angle The specific content of the parameter evolution model under dynamic disturbance true triaxial condition is as follows:

[0048] Based on the test data of the whole process of mechanical behavior of deep hard rock under dynamic disturbance, the initial cohesion and the initial internal friction angle , the residual cohesion and the residual internal friction angle are solved.

[0049] Combined with the initial cohesion and the initial internal friction angle , the residual cohesion , the residual internal friction angle and the dynamic disturbance damage factor, the parameter evolution model of the cohesion and the internal friction angle under dynamic disturbance true triaxial condition is constructed, which is expressed as:

[0050] ;

[0051] ;

[0052] ;

[0053] ;

[0054] ;

[0055] wherein represents the internal variable increment of the m-th deformation stage; represents the final value of the internal variable of the m-th deformation stage; represents the final value of the internal variable of the m-th deformation stage; is the positive operator; represents the weakening ratio of the cohesion of the m-th deformation stage; represents the weakening ratio of the cohesion of the m-th deformation stage; ​​​​​indicates the enhancement ratio of the internal friction angle in the first indicates the enhancement ratio of the internal friction angle in the first

[0056] The beneficial effects produced by the above technical solutions are:

[0057] The deformation and rupture characteristics of deep hard rock under the action of dynamic disturbance true triaxial show different from the traditional understanding. When establishing the dynamic disturbance damage mechanics model of hard rock, the irreversible strain of hard rock caused by dynamic disturbance is considered, the dynamic disturbance influence factor D is proposed, and the damage effect of stress state, disturbance amplitude, disturbance frequency and disturbance times on deep hard rock is considered. The reliability of the result is improved when judging the mechanical behavior of deep hard rock under the action of dynamic disturbance true triaxial, and the rupture process of deep engineering hard rock under the action of stress path and dynamic disturbance can be more accurately described. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 It is a flow chart of the method for establishing a deep hard rock dynamic disturbance three-dimensional mechanics model in the embodiment;

[0059] Figure 2 It is a typical stress-strain curve diagram of deep hard rock excavation true triaxial compression test in the embodiment;

[0060] Figure 3 It is a typical stress-strain curve diagram of deep hard rock dynamic disturbance true triaxial test in the embodiment;

[0061] Figure 4 It is a schematic diagram of macro-microscopic typical rupture morphology of deep hard rock dynamic disturbance true triaxial test in the embodiment;

[0062] Figure 5 It is a macroscopic rupture surface scanning result diagram in the embodiment;

[0063] Figure 6 It is a deep hard rock dynamic disturbance true triaxial internal variable parameter evolution law diagram in the embodiment. DETAILED DESCRIPTION

[0064] In order to facilitate the understanding of the present application, the specific embodiments of the present application are further described in detail below in combination with the drawings and embodiments. The following embodiments are used to illustrate the present application, but not to limit the scope of the present application. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0065] In the embodiment, granite taken from deep buried hard rock tunnel is used as rock sample to construct and verify the accuracy and rationality of the dynamic disturbance damage mechanics model of rock under true triaxial stress state.​​

[0066] This embodiment provides a method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock, such as... Figure 1 As shown, the method includes the following steps:

[0067] A true triaxial test without dynamic disturbance was conducted on deep hard rock samples taken from deep tunnel engineering, and the test data of the mechanical behavior of deep hard rock under dynamic disturbance were recorded.

[0068] The specific content of the true triaxial test without dynamic disturbance conducted on deep hard rock samples taken from deep tunnel engineering, and the recording of the entire process of mechanical behavior of deep hard rock under no-dynamic disturbance, is as follows:

[0069] For deep tunnel engineering, obtain the surrounding rock stress data at different distances from the tunnel face; wherein the surrounding rock stress data includes: intermediate principal stress. and minimum principal stress .

[0070] In this embodiment, for a deep-buried tunnel in Southwest China, the stress data of the surrounding rock at different distances from the tunnel face at the construction site are obtained through in-situ stress inversion and field measurement, and this data is used as the basis for setting stress parameters during the test.

[0071] Based on all the acquired surrounding rock stress data, a stress path was designed. Following the designed stress path, a true triaxial test without dynamic disturbance was conducted on the deep hard rock using a dynamic disturbance true triaxial testing machine to obtain the peak strength of the deep hard rock under no-dynamic disturbance conditions. The experiment recorded the experimental data of the mechanical behavior of deep hard rock under no-power disturbance, and then plotted the full stress-strain curve of deep hard rock under no-power disturbance.

[0072] The experimental data of the mechanical behavior of the deep hard rock under true triaxial loading are: the stress and strain values ​​of the deep hard rock in three directions under the principal stress variation.

[0073] In this embodiment, granite samples taken from a deep-buried tunnel in Southwest China were prepared into true triaxial rock samples, i.e., deep hard rock. A true triaxial test without dynamic disturbance was conducted under specific confining pressure conditions to obtain the peak strength of the true triaxial rock sample under these conditions. Figure 2 As shown, the test data of the mechanical behavior of the true triaxial rock sample were recorded throughout the entire process, including the pre-peak and post-peak stress and strain magnitudes of deep hard rock in the three directions of principal stress, intermediate principal stress and minimum principal stress under the change of principal stress, and the full stress-strain curves of deep hard rock under the true triaxial excavation stress path were plotted.

[0074] Based on the whole-process test data of the mechanical behavior of deep hard rock under non-dynamic disturbance, true triaxial tests are carried out on deep hard rock taken from deep tunnel engineering under dynamic disturbance, and the whole-process test data of the mechanical behavior of deep hard rock under dynamic disturbance are recorded.

[0075] The deep hard rock used in the true triaxial stress path test of hard rock and the deep hard rock dynamic disturbance true triaxial test is the standard rock sample cut from the same rock, and all the standard rock samples are subjected to uniformity detection before the test.

[0076] In the embodiment, the standard rock sample is cut and polished from the rock taken from the site. Since each naturally formed rock is not completely the same, in order to minimize the discreteness of the test data, the rock sample used is obtained by cutting a large rock, and the sample with obvious defects is removed. Sound wave detection is an efficient means to evaluate internal uniformity, so the embodiment analyzes the uniformity of the sample by sound wave test, selects the rock sample with good uniformity, and makes each standard rock sample obtained from the same rock as close as possible, so as to ensure the reliability of the test results.

[0077] The specific method of the true triaxial test of deep hard rock taken from deep tunnel engineering under dynamic disturbance based on the whole-process test data of the mechanical behavior of deep hard rock under non-dynamic disturbance, and recording the whole-process test data of the mechanical behavior of deep hard rock under dynamic disturbance is as follows:

[0078] According to the peak strength of deep hard rock under non-dynamic disturbance Set several disturbance opportunities.

[0079] In the embodiment, the disturbance opportunities are respectively selected as , , , , , , .

[0080] Obtain the disturbance wave signal of the tunnel engineering site and generate the disturbance wave time-frequency curve, extract the frequency range of the disturbance wave from the disturbance wave time-frequency curve, and then determine several disturbance frequencies based on the disturbance wave signal of the tunnel engineering site and the frequency range of the disturbance wave through Fourier transform .

[0081] In the embodiment, the disturbance wave signals of the tunnel engineering site are continuously collected by arranging monitoring devices at the deep tunnel engineering site. The disturbance wave time-frequency curve of the tunnel engineering site is drawn by using the collected disturbance wave signals, and then the frequency range of the disturbance wave is obtained. The frequency spectrum is obtained by performing Fourier transform on the collected disturbance wave signals, and a plurality of disturbance frequencies are determined in the frequency range of the disturbance wave .

[0082] The rock wave velocity, rock density and surrounding rock particle velocity of the tunnel engineering site are obtained, and a plurality of disturbance amplitudes are calculated by using the measured rock wave velocity, rock density and surrounding rock particle velocity .

[0083] In the embodiment, the rock wave velocity and density of the tunnel engineering site are obtained by carrying out rock wave velocity and density tests at the tunnel engineering site, and the surrounding rock particle velocity of the tunnel engineering site is measured by arranging sensors, and then the disturbance amplitude is obtained according to the rock wave velocity, rock density and surrounding rock particle velocity of the tunnel engineering site .

[0084] All possible dynamic disturbance conditions are generated by traversing all combinations of the disturbance frequency and the disturbance amplitude .

[0085] In the embodiment, all disturbance frequencies and disturbance amplitudes are arranged and combined to generate all possible dynamic disturbance conditions, and the true triaxial test under dynamic disturbance is carried out by controlling variables.

[0086] Based on the stress path designed in the true triaxial test without dynamic disturbance, the true triaxial test of the deep hard rock under dynamic disturbance is carried out according to different dynamic disturbance conditions, and dynamic disturbance is applied at a plurality of disturbance times set during the test to obtain the peak strength of the deep hard rock under dynamic disturbance , and the mechanical behavior whole-process test data of the deep hard rock under dynamic disturbance are recorded, and then the whole stress-strain curve of the deep hard rock under dynamic disturbance is drawn.

[0087] The mechanical behavior whole-process test data of the deep hard rock under dynamic disturbance include: disturbance time, disturbance frequency, strength value, stress value and strain value of the deep hard rock under dynamic disturbance.

[0088] In the embodiment, on the basis of obtaining the peak strength of the deep hard rock without dynamic disturbance, dynamic disturbance is applied, and the disturbance frequency and the disturbance amplitude As the disturbance parameter setting basis, several independent true triaxial tests of deep hard rock under dynamic disturbance are carried out, and the peak strength of deep hard rock under dynamic disturbance is obtained , the influence of dynamic disturbance on rock peak value is determined, the mechanical behavior of deep hard rock under dynamic disturbance is obtained, including the dynamic disturbance deformation data of each stage, and the whole process stress-strain curve of deep hard rock under dynamic disturbance true triaxial is drawn, as shown in Figure 3 .

[0089] For deep hard rock after true triaxial test without dynamic disturbance and deep hard rock after true triaxial test under dynamic disturbance, the failure mode of deep hard rock under different dynamic disturbances is determined by comparing and analyzing the failure mode of deep hard rock after each test.

[0090] In this embodiment, since the failure mode is the final form of brittle and ductile fracture and macroscopic crack, by identifying the failure mode of deep hard rock under different dynamic disturbances, the influence of different dynamic disturbance factors on brittle and ductile fracture and macroscopic crack of deep hard rock can be analyzed. Specifically, the deep hard rock after the test is observed and the macroscopic failure mode is analyzed. In addition, the three-dimensional laser scanning technology is used to scan the failure surface, obtain the JRC value of the failure surface, and scan the section of the failure surface by SEM electron microscope, and comprehensively analyze the failure mode of deep hard rock from macro-microscopic two angles, as shown in Figure 4 and Figure 5 .

[0091] The specific content of the failure mode of deep hard rock under different dynamic disturbances is as follows:

[0092] For any deep hard rock after true triaxial test without dynamic disturbance or after true triaxial test under dynamic disturbance, the deep hard rock is photographed, the crack types of the deep hard rock are observed according to the photographed photos, and the crack failure angle of the deep hard rock is measured.

[0093] In the embodiment, the hard rock is taken out from the hard rock true triaxial stress path test and the deep hard rock dynamic disturbance true triaxial test, and is photographed in a light supplement box to record a macroscopic failure mode. By photographing and recording the macroscopic characteristics of the failure surface, the overall shape and crack distribution of the failure surface can be determined, including: crack types and measured crack failure angles. This helps to determine the key areas of 3D laser scanning, ensuring that all important cracks and failure characteristics are covered during the scanning process; at the same time, it also helps to determine the crack propagation direction and key areas, and then guides the focus of the electron microscope scanning, that is, to select a representative crack area for slicing.

[0094] The 3D laser scanning is performed on the failure surface of the deep hard rock to obtain the coordinates of each point in the failure surface based on the horizontal plane, and the JRC value of the failure surface is calculated based on the coordinates of each point based on the horizontal plane. According to the JRC value of the failure surface, it is determined that the failure mode of the deep hard rock under the macroscopic angle is one of shear failure, tensile failure or mixed failure.

[0095] In the embodiment, according to the coordinate information of each point in the failure surface based on the horizontal plane, a MATLAB program written by the applicant is used to automatically calculate the JRC value (Joint Roughness Coefficient) of the macroscopic failure surface to determine the failure mode of the deep hard rock.

[0096] Based on the crack types, crack failure angles and failure modes of the deep hard rock, a representative area is selected in the failure surface of the deep hard rock, and a slice is taken from the failure surface according to the selected representative area. The SEM electron microscope scanning is performed on the slice to observe and record the microscopic characteristics of the failure surface, and according to the microscopic characteristics of the failure surface, it is determined that the failure mode of the deep hard rock under the microscopic angle is one of shear failure, tensile failure or mixed failure.

[0097] In the embodiment, the macroscopic and microscopic characteristics are combined, and the crack types, failure angles, failure modes and stress concentration are comprehensively considered to select the most representative area. For example, an area with high crack density, consistent failure angle with principal stress and fully developed microscopic cracks is selected. The slice taken from the failure surface is subjected to SEM electron microscope scanning, and according to the microscopic results obtained by scanning, the intergranular failure or transgranular failure, as well as the scratch, tearing edge and other information on the crystal surface can be observed. According to this information, the failure mode of the deep hard rock is further analyzed from the microscopic angle, that is, it is determined that the rock failure mode is tensile failure, shear failure or mixed failure, which is verified by the macroscopic 3D laser scanning results.

[0098] whether the failure mode of the deep hard rock is consistent with the failure mode of the deep hard rock under the macroscopic angle and the microscopic angle of the deep hard rock, if consistent, determining the failure mode of the deep hard rock; if not consistent, re-determining the failure mode of the deep hard rock in combination with the JRC value of the failure surface and the microscopic characteristics of the failure surface.

[0099] Then, by comparing the failure mode of the deep hard rock after the true triaxial test under the unpowered disturbance with the failure mode of the deep hard rock under the true triaxial test under the action of the dynamic disturbance, the failure mode of the deep hard rock under different dynamic disturbances is determined.

[0100] Based on the whole-process test data of the mechanical behavior of the deep hard rock under the action of the dynamic disturbance and the failure mode of the deep hard rock under different dynamic disturbances, a mechanical model of the deep hard rock under the action of the dynamic disturbance is constructed.

[0101] The specific content of the mechanical model of the deep hard rock under the action of the dynamic disturbance is as follows:

[0102] Based on the whole-process test data of the mechanical behavior of the deep hard rock under the action of the dynamic disturbance and the failure mode of the deep hard rock under different dynamic disturbances, the variation law of the peak strength of the deep hard rock under different dynamic disturbance conditions and the deformation amount of the deep hard rock in each disturbance stage under different dynamic disturbance conditions are obtained.

[0103] In the embodiment, based on the different stress , and the deformation amount of the hard rock sample in each disturbance stage under the conditions of different disturbance frequencies f and different disturbance amplitudes A and the variation law of the peak strength of the hard rock sample under different disturbance conditions .

[0104] According to the whole stress-strain curve of the deep hard rock under the action of the dynamic disturbance, the mechanical behavior of the deep hard rock under the action of the dynamic disturbance is divided into three disturbance stages, which are: the elastic deformation stage, the plastic deformation stage and the irreversible deformation stage.

[0105] In the embodiment, at the initial stage of loading, the hard rock shows elastic behavior, the stress is proportional to the strain, and the Hooke's law is followed, at this time, the deep hard rock is in the elastic deformation stage. When the stress exceeds the yield strength of the deep hard rock, the deep hard rock enters the plastic stage, the strain continues to increase, but the stress no longer increases significantly. When the stress reaches the peak strength of the deep hard rock, the deep hard rock starts to break and form macroscopic cracks, at this time, the deep hard rock enters the irreversible deformation stage. The peak strength point is the highest point of the stress-strain curve.​

[0106] Based on the test data of the whole process of the mechanical behavior of the deep hard rock under the action of dynamic disturbance, the elastic deformation, the plastic deformation and the irreversible deformation of the deep hard rock under the action of dynamic disturbance are calculated respectively.

[0107] In the embodiment, the irreversible deformation of the deep hard rock under the action of dynamic disturbance should be zero theoretically under the action of no dynamic disturbance, so the irreversible deformation caused by pure disturbance is extracted by comparing the difference between the plastic strain under the action of no dynamic disturbance and the plastic strain under the action of dynamic disturbance.

[0108] According to the elastic deformation, the plastic deformation and the irreversible deformation of the deep hard rock under the action of dynamic disturbance, a mechanical model of the deep hard rock under the action of dynamic disturbance is constructed.

[0109] The construction method of the mechanical model of the deep hard rock under the action of dynamic disturbance is as follows:

[0110] Based on the elastic-plastic constitutive relation, according to the elastic deformation, the plastic deformation and the irreversible deformation of the deep hard rock under the action of dynamic disturbance, an incremental stress-strain relation of the deep hard rock is established.

[0111] (1) ;

[0112] (2) ;

[0113] (3) ;

[0114] (4) ;

[0115] wherein represents the total strain of the deep hard rock; represents the elastic strain of the deep hard rock; represents the plastic strain of the deep hard rock; represents the irreversible strain of the deep hard rock under the action of dynamic disturbance; represents the true stress of the deep hard rock; represents the plastic damage coefficient; represents the dynamic disturbance damage coefficient, which is the same as the dynamic disturbance influence factor D established in the following; represents the effective stress of the deep hard rock; is the disturbance period; is the disturbance frequency; is the disturbance time.

[0116] The effective stress of the deep hard rock and the true stress of the deep hard rock are represented as:

[0117] (5);

[0118] (6);

[0119] wherein represents the elastic modulus; represents the plastic history variable of the final residual state; represents the plastic history at a certain time; represents the history variable of the dynamic disturbance irrecoverable deformation; represents the dynamic disturbance irrecoverable deformation history at a certain time.

[0120] The stress-strain relationship of the deep hard rock in incremental form is represented as:

[0121] (7);

[0122] (8);

[0123] wherein represents the stress increment tensor; represents the strain increment tensor; is the anisotropic elastic stiffness tensor based on the Young's modulus , the Poisson's ratio and the plastic history ; the plastic history is taken as an internal variable, representing the inelastic irreversible deformation according to the second law of thermodynamics; is the dynamic disturbance irrecoverable strain increment; represents the plastic strain increment; represents the brittleness index.

[0124] According to the plastic flow rule, the plastic strain increment of the deep hard rock under the dynamic disturbance true triaxial condition is represented as:

[0125] (9);

[0126] (10);

[0127] (11);

[0128] (12);

[0129] wherein represents the failure criterion; represents the association of the failure criterion with the real stress of the deep hard rock and the related parameters of the failure criterion. represents the plasticity increment factor; represents the relevant parameter of the failure criterion associated with the plasticity history ; is the plastic potential function, the non-associative flow rule is adopted, that is ; represents the relevant parameter of the plastic potential function and the true stress and plastic potential function of deep hard rock associated with the plasticity history ; represents the relevant parameter of the plastic potential function associated with the plasticity history ; is the dilatancy angle, the internal friction angle is taken as the dilatancy angle in the embodiment.

[0130] The plastic potential function is expressed as a curved surface in the three-dimensional principal stress space, that is, a plastic potential three-dimensional surface, and the dilatancy angle controls the shape of the plastic potential three-dimensional surface, so the plastic potential function is expressed as:

[0131] (13) ;

[0132] (14) ;

[0133] (15) ;

[0134] (16) ;

[0135] (17) ;

[0136] wherein represents the first invariant of the stress tensor; represents the uniaxial tensile strength; according to the relationship between and , the plastic potential function is divided into two parts, wherein serves as the separation boundary between the tensile zone and the shear zone; represents the shear zone dominant zone, and the deep hard rock is mainly damaged by shear slip; represents the tensile zone, and the deep hard rock is mainly damaged by tensile fracture; represents the second invariant of the deviatoric stress tensor; is the dilatancy angle correction factor, which represents the degree of volume expansion in the plastic flow process; is the shear strength correction factor; represents the cohesion; is related to the lode angle , which is used to describe the difference in shear response under different stress states; is a function of stress tensor transformation, representing the lateral dimension of the plastic zone in the tension zone; is a function of stress tensor transformation, controlling the position of the plastic zone in the tension zone.

[0137] Determination of dynamic disturbance irrecoverable strain increment of deep hard rock under dynamic disturbance true triaxial condition , is expressed as:

[0138] (18) ;

[0139] wherein is the average strain fitting generated by single disturbance under different stress states and different amplitude disturbances; is a dynamic disturbance multiplier, which leads to an increase in the strain rate of the irrecoverable strain caused by disturbance as the number of disturbances increases.

[0140] According to the experimental data of the mechanical behavior of deep hard rock under dynamic disturbance, the dynamic disturbance damage factor is determined, which is expressed as:

[0141] (19) ;

[0142] (20) ;

[0143] wherein is the dynamic disturbance damage factor; and are both material parameters, which are obtained through the experimental data of the mechanical behavior of deep hard rock under dynamic disturbance; represents the critical stress of dynamic disturbance, which is obtained through the inflection point of the deformation rate in the direction of the three principal stresses in the experimental data.

[0144] In this embodiment, the dynamic disturbance damage factor is represented by a function containing the disturbance amplitude and the disturbance frequency under the action of dynamic disturbance true triaxial. Through the analysis and arrangement of the obtained experimental data, the elastic and plastic deformation and the irreversible deformation of deep hard rock in the disturbance process at each stage are obtained, and then the mechanical model of hard rock under the condition of dynamic disturbance true triaxial is constructed.

[0145] Based on the mechanical model of deep hard rock under the condition of dynamic disturbance true triaxial, the cohesion and the internal friction angle under the condition of dynamic disturbance true triaxial are determined.

[0146] In this embodiment, based on the experimental data of deep hard rock under the condition of dynamic disturbance true triaxial, the mechanical model is established, the internal variable is determined, and the evolution law of the cohesion c and the internal friction angle φ in the whole deformation and fracture process is obtained, as shown in Figure 6 .

[0147] The mechanical model based on deep hard rock under true triaxial conditions of dynamic disturbance determines the cohesion. and internal friction angle The specific content of the parameter evolution model under true triaxial conditions of dynamic disturbance is as follows:

[0148] Based on experimental data of the entire mechanical behavior of deep hard rock under dynamic disturbance, the initial cohesion is solved. and initial internal friction angle Residual cohesion and residual internal friction angle .

[0149] Combined with initial cohesion and initial internal friction angle Residual cohesion residual internal friction angle And dynamic disturbance damage factors, to build cohesion and internal friction angle The parameter evolution model under true triaxial conditions of dynamic disturbance is expressed as:

[0150] (twenty one);

[0151] (twenty two);

[0152] (twenty three);

[0153] (twenty four);

[0154] (25);

[0155] in Indicates the first Increment of internal variables in each deformation stage; Indicates the first The final values ​​of the internal variables in each deformation stage; Indicates the first The final values ​​of the internal variables in each deformation stage; It is a positive operator, represented as: ; Indicates the first The rate of decrease in cohesion during each deformation stage; Indicates the first The rate of decrease in cohesion during each deformation stage; Indicates the first The rate of increase in friction angle within each deformation stage; Indicates the first The enhancement ratio of the internal friction angle in the deformation stage.

[0156] Finally, it should be noted that the above examples are intended to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope defined by the present application.

Claims

1. A method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock, characterized in that, This method includes the following steps: A true triaxial test without dynamic disturbance was conducted on deep hard rock samples taken from deep tunnel engineering, and the test data of the mechanical behavior of deep hard rock under dynamic disturbance were recorded throughout the entire process. Based on the full-process test data of the mechanical behavior of deep hard rock under no-dynamic disturbance, a true triaxial test under dynamic disturbance was carried out on deep hard rock taken from deep tunnel engineering, and the full-process test data of the mechanical behavior of deep hard rock under dynamic disturbance was recorded. For deep hard rock after true triaxial test without dynamic disturbance and deep hard rock after true triaxial test with dynamic disturbance, the failure mode of deep hard rock under different dynamic disturbances is determined by comparing and analyzing the failure mode of deep hard rock after each test. Based on the experimental data of the whole process of mechanical behavior of deep hard rock under dynamic disturbance and the failure mode of deep hard rock under different dynamic disturbances, a mechanical model of deep hard rock under true triaxial conditions of dynamic disturbance is constructed. Based on a mechanical model of deep hard rock under true triaxial conditions of dynamic disturbance, the cohesion is determined. and internal friction angle Parameter evolution model under true triaxial conditions of dynamic disturbance.

2. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 1, characterized in that, The specific content of the true triaxial test without dynamic disturbance conducted on deep hard rock samples taken from deep tunnel engineering, and the recording of the entire process of mechanical behavior of deep hard rock under no-dynamic disturbance, is as follows: For deep tunnel engineering, obtain the surrounding rock stress data at different distances from the tunnel face; The surrounding rock stress data mentioned above includes: intermediate principal stress. and minimum principal stress ; Based on all the acquired surrounding rock stress data, a stress path was designed. Following the designed stress path, a true triaxial test without dynamic disturbance was conducted on the deep hard rock using a dynamic disturbance true triaxial testing machine to obtain the peak strength of the deep hard rock under no-dynamic disturbance conditions. The test data of the mechanical behavior of deep hard rock under no-power disturbance were recorded, and then the full stress-strain curve of deep hard rock under no-power disturbance was plotted. The experimental data of the mechanical behavior of the deep hard rock under true triaxial loading are: the stress and strain values ​​of the deep hard rock in three directions under the principal stress variation.

3. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 2, characterized in that, The deep hard rock used in the true triaxial stress path test of hard rock and the true triaxial dynamic disturbance test of deep hard rock were all standard rock samples cut from the same rock, and all standard rock samples passed the homogeneity test before the test.

4. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 3, characterized in that, The specific method for conducting true triaxial tests on deep hard rock samples taken from deep tunnel engineering under dynamic disturbance, based on the full-process test data of the mechanical behavior of deep hard rock under no-dynamic disturbance, and recording the full-process test data of the mechanical behavior of deep hard rock under dynamic disturbance is as follows: Based on the peak strength of deep hard rock under undisturbed conditions Set several different disturbance timings; The disturbance wave signal at the tunnel construction site is acquired and a time-frequency curve of the disturbance wave is generated. The frequency range of the disturbance wave is extracted from the time-frequency curve. Based on the disturbance wave signal and the frequency range of the disturbance wave at the tunnel construction site, several disturbance frequencies are determined by Fourier transform. ; The rock wave velocity, rock density, and surrounding rock particle velocity at the tunnel engineering site are obtained, and several disturbance amplitudes are calculated using the measured rock wave velocity, rock density, and surrounding rock particle velocity. ; By iterating through all perturbation frequencies and disturbance amplitude The combination of these factors generates all possible dynamic disturbance conditions. Based on the stress path designed in the true triaxial test without dynamic disturbance, true triaxial tests were conducted on the deep hard rock under dynamic disturbance conditions according to different dynamic disturbance conditions. During the test, dynamic disturbance was applied at several predetermined disturbance times to obtain the peak strength of the deep hard rock under dynamic disturbance. The test data of the mechanical behavior of deep hard rock under dynamic disturbance were recorded, and then the full stress-strain curve of deep hard rock under dynamic disturbance was plotted. The experimental data on the mechanical behavior of the deep hard rock under dynamic disturbance includes: disturbance time, number of disturbances, strength value, stress value and strain value of the deep hard rock under dynamic disturbance.

5. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 4, characterized in that, The specific details of determining the failure modes of deep hard rock under different dynamic disturbances by comparing and analyzing the failure modes of deep hard rock after each test in true triaxial tests without dynamic disturbance and those after true triaxial tests with dynamic disturbance are as follows: For any deep hard rock in a true triaxial test under no-dynamic disturbance or under a true triaxial test under dynamic disturbance, determine the type of crack in the deep hard rock and measure the crack failure angle of the deep hard rock. 3D laser scanning was performed on the failure surface of the deep hard rock to obtain the coordinates of each point on the failure surface based on the horizontal plane. The JRC value of the failure surface was calculated using the coordinates of each point on the horizontal plane. Based on the JRC value of the failure surface, the failure mode of the deep hard rock under the macroscopic angle was determined to be one of shear failure, tension failure or mixed failure. Based on the crack types, crack failure angles, and failure modes of the deep hard rock, representative areas were selected from the failure surfaces of the deep hard rock. Slices were taken from the failure surfaces based on the selected representative areas, and the slices were scanned by SEM electron microscopy to observe and record the microscopic features of the failure surfaces. Based on the microscopic features of the failure surfaces, it was determined that the failure mode of the deep hard rock at the microscopic angle was one of shear failure, tensile failure, or mixed failure. Compare the failure modes of the deep hard rock from a macroscopic perspective with those from a microscopic perspective. If they are consistent, determine the failure mode of the deep hard rock. If they are inconsistent, re-evaluate the failure mode of the deep hard rock by combining the JRC value of the failure surface and the microscopic characteristics of the failure surface. By comparing the failure modes of deep hard rock after true triaxial tests without dynamic disturbance with the failure modes of deep hard rock after all true triaxial tests with dynamic disturbance, the failure modes of deep hard rock under different dynamic disturbances are determined.

6. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 5, characterized in that, The specific content of constructing a mechanical model of deep hard rock under true triaxial conditions based on the full-process experimental data of the mechanical behavior of deep hard rock under dynamic disturbance and the failure modes of deep hard rock under different dynamic disturbances is as follows: Based on the experimental data of the entire mechanical behavior of deep hard rock under dynamic disturbance and the failure modes of deep hard rock under different dynamic disturbances, the peak strength of deep hard rock under different dynamic disturbance conditions was obtained. The variation pattern and the deformation of deep hard rock at each disturbance stage under different dynamic disturbance conditions; Based on the full stress-strain curve of deep hard rock under dynamic disturbance, the mechanical behavior of deep hard rock under dynamic disturbance is divided into three disturbance stages: elastic deformation stage, plastic deformation stage and irreversible deformation stage. Based on the experimental data of the mechanical behavior of deep hard rock under dynamic disturbance, the elastic deformation, plastic deformation and irreversible deformation under dynamic disturbance were calculated respectively. Based on the elastic deformation, plastic deformation, and irreversible deformation caused by dynamic disturbance in deep hard rock, a mechanical model of deep hard rock under true triaxial conditions of dynamic disturbance is constructed.

7. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 6, characterized in that, The method for constructing the mechanical model of deep hard rock under dynamic disturbance true triaxial conditions is as follows: Based on the elastoplastic constitutive model, and considering the elastic deformation, plastic deformation, and irreversible deformation caused by dynamic disturbance in deep hard rock, an incremental stress-strain relationship for deep hard rock is established, expressed as: ； ； in Represents the stress increment tensor; Represents the strain increment tensor; Based on Young's modulus Poisson's ratio and the history of plasticity Anisotropic elastic stiffness tensor; plastic history As an internal variable, it represents inelastic irreversible deformation according to the second law of thermodynamics; This represents the irrecoverable strain increment caused by dynamic disturbance in deep hard rock under true triaxial conditions of dynamic disturbance. Indicates the increment of plastic strain; Indicates brittleness index; For the incremental stress-strain relationship in deep hard rock, the plastic strain increment of deep hard rock under dynamic disturbance true triaxial conditions is determined according to the plastic flow law. Simultaneously, the irrecoverable strain increment due to dynamic disturbance in deep hard rock under true triaxial conditions was determined. ; Based on the experimental data of the entire process of mechanical behavior of deep hard rock under dynamic disturbance, the dynamic disturbance damage factor is determined.

8. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 7, characterized in that, The deep hard rock under true triaxial conditions of dynamic disturbance exhibits irreversible strain increments. , represented as: ； in To consider the average strain fitting generated during a single disturbance under different stress states and for different amplitude disturbances; For dynamic perturbation multipliers; The disturbance time.

9. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 8, characterized in that, The dynamic disturbance damage factor is: ； in The damage factor is the dynamic disturbance. and All of these are material parameters, obtained from experimental data on the mechanical behavior of deep hard rock under dynamic disturbance. Indicates the critical stress of dynamic disturbance; The number of perturbations.

10. The method for establishing a three-dimensional mechanical model of dynamic disturbance in deep hard rock according to claim 9, characterized in that, The mechanical model based on deep hard rock under true triaxial conditions of dynamic disturbance determines the cohesion. and internal friction angle The specific content of the parameter evolution model under true triaxial conditions of dynamic disturbance is as follows: Based on experimental data of the entire mechanical behavior of deep hard rock under dynamic disturbance, the initial cohesion is solved. and initial internal friction angle Residual cohesion and residual internal friction angle ; Combined with initial cohesion and initial internal friction angle Residual cohesion residual internal friction angle And dynamic disturbance damage factors, to build cohesion and internal friction angle The parameter evolution model under true triaxial conditions of dynamic disturbance is expressed as: ； ； ； ； ； in Indicates the first Increment of internal variables in each deformation stage; Indicates the first The final values ​​of the internal variables in each deformation stage; Indicates the first The final values ​​of the internal variables in each deformation stage; It is the positive operator; Indicates the first The rate of decrease in cohesion during each deformation stage; Indicates the first The rate of decrease in cohesion during each deformation stage; Indicates the first The rate of increase in friction angle within each deformation stage; Indicates the first The ratio of the increase in friction angle within each deformation stage.

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