Dynamic disturbance failure criterion of rock mass structural plane under true triaxial stress

Abstract

The invention discloses a dynamic disturbance failure criterion for rock mass structural planes under true three-dimensional stress, and its construction process includes the following steps: S1. Conduct a true triaxial disturbance shear test to determine the disturbance critical shear strength τ of the rock mass structural plane c ; S2. Construct a disturbance critical shear strength function model G1 under different amplitudes A; S3. Construct a disturbance critical shear strength function model G2 under the action of different frequencies f; S4. Construct a disturbance critical shear strength function model G3 under different normal stresses σ n ; S5. Construct a disturbance critical shear strength function model G4 under different lateral stresses σ p ; S6. Construct a disturbance critical shear strength function model G5 under a three-dimensional stress state to determine the envelope surface morphology of the disturbance critical shear strength function; S7. Conduct a true triaxial disturbance shear test under test conditions different from those in S1 to verify and improve the disturbance critical shear strength function model of the rock mass structural plane under a three-dimensional stress state, and construct a dynamic disturbance failure criterion for the rock mass structural plane under true three-dimensional stress.

Description

Technical Field

[0001] The present invention relates to the field of rock mechanical properties and engineering research, and particularly to a dynamic disturbance failure criterion for rock mass structural planes under true triaxial stress. Background Art

[0002] Rock mass structural planes play a key role in the types of disasters and stability of rock engineering after excavation. Especially in deep-buried tunnel engineering, the rock mass of the surrounding rock structural plane is in a true triaxial in-situ stress state and is affected by three-way stresses of shear stress, normal stress, and lateral stress. During the tunnel construction process, strong stress waves are generated due to blasting, mechanical drilling, or rock bursts and fractures in adjacent areas. When the strong stress waves propagate in the surrounding rock, they quickly decay into low-amplitude and low-frequency disturbance waves. These disturbance waves can still promote the expansion and penetration of a large number of microcracks inside the damaged layered rock, resulting in failure. The failure spreads along the bedding plane, leading to the expansion of the damaged area of the surrounding rock and even disasters. Traditional rock structural plane criteria such as the Mohr-Coulomb strength criterion do not consider the influence of lateral stress, the amplitude, and frequency of dynamic disturbance stress. The triggering conditions for shear failure of rock mass structural planes predicted under three-dimensional stress states do not fully adapt to deep rock engineering, resulting in inaccurate prediction of disasters of surrounding rock structural planes. Therefore, it is necessary to construct a dynamic disturbance failure criterion for rock mass structural planes under true triaxial stress as a criterion for dynamic disturbance shear failure of rock mass structural planes under true triaxial stress conditions. Summary of the Invention

[0003] The purpose of the present invention is to provide a dynamic disturbance failure criterion for rock mass structural planes under true triaxial stress, as a criterion for shear failure of rock mass structural planes under true triaxial stress levels, and to provide a theoretical basis for predicting shear failure disasters of rock mass containing structural planes in high-stress deep engineering.

[0004] To achieve the above technical objectives, the present invention provides a dynamic disturbance failure criterion for rock mass structural planes under true triaxial stress, which includes:

[0005] S1. Conduct true triaxial disturbance shear tests to determine the disturbance critical shear strength τ n of the rock mass structural plane under different normal stresses σ p , different lateral stresses σ c , different amplitudes A, and different frequencies f;

[0006] S2. Obtain the variation law of the disturbance critical shear strength τ n、 of the rock mass structural plane under the same normal stress σ p , lateral stress σ c , frequency f, and different amplitudes A under true triaxial conditions, and construct a function model G 1 (A) of the disturbance critical shear strength of the rock mass structural plane;

[0007] S3. Obtain the same normal stress σn、 Lateral stress σ p , amplitude A and the critical shear strength τ of the rock mass structural plane under the action of different frequencies f c Variation law, and construct the function model G 2 (f);

[0008] S4. Obtain the same lateral stress σ p , amplitude A, frequency f and the critical shear strength τ of the rock mass structural plane under the action of different normal stresses σ n Variation law, and construct the function model G c of the critical shear strength of the rock mass structural plane disturbance 3 (σ n );

[0009] S5. Obtain the same normal stress σ n , amplitude A, frequency f and the critical shear strength τ of the rock mass structural plane under the action of different lateral stresses σ p Variation law, and construct the function model G c of the critical shear strength of the rock mass structural plane disturbance 4 (σ p );

[0010] S6. Based on steps S2 and S3, S4, S5, construct the function model G 5 (σ n , σ p , A, f) of the critical shear strength of the rock mass structural plane disturbance under the three-dimensional stress state, and determine the envelope surface shape of the function of the critical shear strength of the rock mass structural plane disturbance;

[0011] S7. Conduct true triaxial disturbance shear tests on the rock mass structural plane under combinations of normal stress σ n , lateral stress σ p , amplitude A and frequency f different from those in S1, obtain the corresponding critical shear strength of the rock mass structural plane disturbance, and verify and improve the function model G 5 (σ n , σ p , A, f). It is characterized in that the construction method of the dynamic disturbance failure criterion G(σ n , σ p , A, f) of the rock mass structural plane under true three-dimensional stress is as follows:

[0012] S7.1. Conduct true triaxial disturbance shear tests under combinations of normal stress σ n , lateral stress σ p , amplitude A and frequency f different from those in S1, and obtain the test value τ c of the corresponding critical shear strength of the rock mass structural plane disturbance;​​

[0013] S7.2. Substitute the normal stress σ n , lateral stress σ p , amplitude A, and frequency f different from those in S1 into the critical shear strength function model G 5 (σ n , σ p , A, f) of the rock mass structural plane under three-dimensional stress state to obtain the predicted value τ g of the critical shear strength of the rock mass structural plane disturbance;

[0014] S7.3. Calculate the root mean square of the experimental value τ c and the predicted value τ g of the critical shear strength of the rock mass structural plane disturbance. Within the error limit, construct the dynamic disturbance failure criterion G(σ n , σ p , A, f) of the rock mass structural plane under true three-dimensional stress:

[0015]

[0016] where, is the internal friction angle, σ ρ is the lateral stress corresponding to the maximum shear stress of the rock mass structural plane, K is the lateral stress with the same critical shear strength of disturbance when the lateral stress is 0, and P, B, C, and D are model parameters.

[0017] In the step S1, the method for conducting true triaxial disturbance shear tests under different normal stresses σ n and different lateral stresses σ p , different amplitudes A, and different frequencies f to obtain the corresponding critical shear strength τ c of disturbance is as follows:

[0018] S1.1. Obtain the test data of the dynamic disturbance shear loading failure of the rock mass structural plane under different test conditions through true triaxial disturbance shear tests;

[0019] S1.2. Plot the τ-ε τ relationship diagram by taking the shear stresses and strains at each level under the condition of equal number of cycles;

[0020] S1.3. Define the stress at the inflection point where the curve slope suddenly drops as the critical shear strength τ c of disturbance.

[0021] In the step S2, obtain the variation law of the critical shear strength τ n、 of the rock mass structural plane disturbance under the same normal stress σ p , lateral stress, frequency f, and different amplitudes A in true triaxial conditions, and construct the critical shear strength function model G c of the rock mass structural plane disturbance1 The method of (A) is as follows:

[0022] S2.1. Based on the critical shear strength of disturbance obtained in step S1, construct the critical shear strength of disturbance τ of the rock mass structural plane under the same normal stress σ in the three-dimensional stress state n、 lateral stress σ p , frequency f and different amplitudes A; c variation law;

[0023] S2.2. Construct the function model G(A) of the critical shear strength of disturbance of the rock mass structural plane: 1 (A):

[0024] G 1 (A) = a + b·A (1) α (1)

[0025] where a, b, and α are model parameters.

[0026] In step S3, the method of obtaining the variation law of the critical shear strength of disturbance τ of the rock mass structural plane under the same normal stress σ, lateral stress σ, amplitude A, and different frequencies f in true triaxial test and constructing the function model G(f) of the critical shear strength of disturbance of the rock mass structural plane is as follows: n、 lateral stress σ p , amplitude A and different frequencies f; c variation law, and construct the function model G(f) of the critical shear strength of disturbance of the rock mass structural plane: 2 (f):

[0027] S3.1. Based on the critical shear strength of disturbance obtained in step S1, construct the variation law of the critical shear strength of disturbance τ of the rock mass structural plane under the same normal stress σ, lateral stress σ, amplitude A, and different frequencies f in the three-dimensional stress state; n、 lateral stress σ p , amplitude A and different frequencies f; c variation law;

[0028] S3.2. Construct the function model G(f) of the critical shear strength of disturbance of the rock mass structural plane: 2 (f):

[0029] G 2 (f) = c + ln(h·f) (2) d ) (2)

[0030] where c, d, and h are model parameters.

[0031] In step S4, the method of obtaining the variation law of the critical shear strength of disturbance τ of the rock mass structural plane under the same lateral stress σ, amplitude A, frequency f, and different normal stresses σ and constructing the function model G(σ) of the critical shear strength of disturbance of the rock mass structural plane is as follows: p , amplitude A, frequency f and different normal stresses σ n ; c variation law, and construct the function model G(σ) of the critical shear strength of disturbance of the rock mass structural plane: 3 (σ n ):

[0032] S4.1. Construct the variation law of the critical shear strength of the rock mass structural plane under the same lateral stress σ p , amplitude A, frequency f and different normal stresses σ n acting on the critical shear strength τ c of the rock mass structural plane;

[0033] S4.2. Construct the function model G 3 (σ n ) of the critical shear strength of the rock mass structural plane under disturbance:

[0034]

[0035] where i is a model parameter, and is the internal friction angle.

[0036] In the said step S5, the method for obtaining the variation law of the critical shear strength of the rock mass structural plane under the same normal stress σ n , amplitude A, frequency f and different lateral stresses σ p acting on it and constructing the function model G c (σ 4 ) is as follows: p ) is as follows:

[0037] S5.1. Based on the critical shear strength of disturbance obtained in step S1, construct the variation law of the critical shear strength of the rock mass structural plane under the same normal stress σ n , amplitude A, frequency f and different lateral stresses σ p acting on it; c ;

[0038] S5.2. Construct the function model G 4 (σ p ):

[0039]

[0040] where l and r are model parameters, σ ρ is the lateral stress corresponding to the maximum shear stress of the rock, and K is the lateral stress at which the strength is the same as the critical shear strength of disturbance when the lateral stress is 0.

[0041] In the said step S6, based on steps S2, S3, S4 and S5, construct the function model G 5 (σ n ,σ p, A, f), the method for determining the envelope shape of the critical shear strength function of the rock mass structural plane is as follows:

[0042] S6.1. Based on the shear peak strength law of the rock mass structural plane under different normal stresses, different lateral stresses, different amplitudes, and different frequencies in the three-dimensional stress state, construct the variation law of the critical shear strength τ of the rock mass structural plane under the three-dimensional stress state; c Variation law;

[0043] S6.2. Construct the critical shear strength function model G of the rock mass structural plane under the three-dimensional stress state 5 (σ n , σ p , A, f):

[0044]

[0045] where b, d, h, r are model parameters, and n is the cohesion;

[0046] S6.3. According to the constructed critical shear strength function model of the rock mass structural plane, determine the envelope shape of the critical shear strength function of the rock mass structural plane.

[0047] In the step S7, conduct a true triaxial disturbance shear test on the rock mass structural plane under a combination of normal stress σ n , lateral stress σ p , amplitude A, and frequency f different from those in S1 to obtain the corresponding critical shear strength of the rock mass structural plane disturbance, and verify and improve the critical shear strength function model G 5 (σ n , σ p , A, f) of the rock mass structural plane under the three-dimensional stress state. The construction method of the dynamic disturbance failure criterion G(σ n , σ p , A, f) of the rock mass structural plane under the true three-dimensional stress is as follows:

[0048] S7.1. Conduct a true triaxial disturbance shear test on the rock mass structural plane under a combination of normal stress σ n , lateral stress σ p , amplitude A, and frequency f different from those in S1 to obtain the test value τ of the corresponding critical shear strength of the rock mass structural plane disturbance; c ;

[0049] S7.2. Substitute the normal stress σ n , lateral stress σ p , amplitude A, and frequency f different from those in S1 in S7.1 into the critical shear strength function model G 5 (σ n , σ p, A, f), obtain the predicted value τ of the critical shear strength of the rock mass structural plane g ;

[0050] S7.3. Calculate the test value τ of the critical shear strength of the rock mass structural plane under dynamic disturbance c and the predicted value τ g to obtain the root mean square. Within the error limit, construct the dynamic disturbance failure criterion G(σ n , σ p , A, f) of the rock mass structural plane under true three-dimensional stress:

[0051]

[0052] where is the internal friction angle, σ ρ is the lateral stress corresponding to the maximum shear stress of the rock mass structural plane, K is the lateral stress that is the same as the critical shear strength of the disturbance when the lateral stress is 0, and P, B, C, and D are model parameters.

[0053] The beneficial effects of the present invention are as follows:

[0054] 1. Based on the critical shear strength of the rock mass structural plane under dynamic disturbance considering the three-dimensional stress state, the present invention constructs a three-dimensional failure criterion for the rock mass structural plane considering the combined action of normal stress, lateral stress, dynamic disturbance stress amplitude, and frequency, which completely characterizes the law of the critical shear strength of the rock mass structural plane under three-dimensional stress.

[0055] 2. The present invention constructs a dynamic disturbance shear strength function of the rock mass structural plane under true three-dimensional stress through true triaxial shear tests. The physical meanings of the parameters are clear and can be used as a criterion for judging the shear failure of the rock mass of the surrounding rock structure of tunnel engineering.

[0056] 3. After secondary development of the dynamic disturbance failure criterion of the rock mass structural plane under true three-dimensional stress constructed by the present invention, it can be used for the stability analysis and prediction of the surrounding rock with structural planes in underground rock engineering. Description of the Drawings

[0057] Figure 1 is the construction flow chart of the dynamic disturbance failure criterion of the rock mass structural plane under true three-dimensional stress of the present invention;

[0058] Figure 2 is the definition diagram of the critical shear strength τ c of granite;

[0059] Figure 3 is the variation law of the critical shear strength of granite with amplitude under different amplitude conditions;

[0060] Figure 4 is the variation law of the critical shear strength of granite with frequency under different frequency conditions;

[0061] Figure 5 is the variation law of the disturbance critical shear strength of granite with the normal stress under different normal stress conditions;

[0062] Figure 6 is the variation law of the disturbance critical shear strength of granite with the lateral stress under different lateral stress conditions;

[0063] Figure 7 is the three-dimensional failure criterion and envelope surface of the dynamic disturbance failure of the granite structural plane considering the amplitude and frequency effects;

[0064] Figure 8 is the dynamic disturbance failure criterion, envelope surface and prediction of the rock mass structural plane under the true three-dimensional stress of granite. Specific implementation manner

[0065] The following describes the specific implementation manner of the present invention with reference to the accompanying drawings, but the present invention is not limited to the scope of the specific implementation manner. It should be noted here that any creation based on the present invention or creation relying on the present invention is within the protection scope of the present invention.

[0066] Example 1:

[0067] This example provides a method for constructing and verifying the accuracy and rationality of the dynamic disturbance failure criterion of the rock mass structural plane under true three-dimensional stress with granite as the rock sample.

[0068] Figure 1 The construction flow chart of the dynamic disturbance failure criterion of the rock mass structural plane under true three-dimensional stress is shown. This method includes steps S1 to S7:

[0069] In step S1, a true triaxial disturbance shear test is carried out to determine the disturbance critical shear strength τ of the granite structural plane under different normal stresses σ n and different lateral stresses σ p , different amplitudes A, and different frequencies f. The test of taking the shear stress and strain at each level under the condition of equal cycle times to draw the τ-ε c relation curve cluster; the shear stress at the inflection point of the sudden change of the slope of the curve cluster is defined as the disturbance critical shear strength τ τ , and the obtaining method is as c shown; calculate and statistically analyze the disturbance critical shear strength of the granite structural plane under different test conditions, as shown in Table 1. Figure 2 shown; calculate and statistically analyze the disturbance critical shear strength of the granite structural plane under different test conditions, as shown in Table 1.

[0070] In step S2, obtain the variation law of the disturbance critical shear strength τ of the rock mass structural plane under the action of the same normal stress σ n、 lateral stress σ p , frequency f and different amplitudes A under true triaxial conditions, as c shown;Figure 3 As shown, the corresponding parameters are obtained as a = 38.59 MPa and b = 3.93 MPa, and at the same time, the critical shear strength G of the granite structural plane disturbance is determined. 1 (A):

[0071] G 1 (A) = 38.59 + 3.93·A -0.32

[0072] In step S3, the critical shear strength τ of the rock mass structural plane disturbance under the action of the same normal stress σ, n、 lateral stress σ p , amplitude A, and different frequencies f is obtained, and the variation law is as c shown. The corresponding model parameters are obtained as c = 44.09 MPa, d = 2.53 MPa, and h = 12.38. At the same time, the shear peak strength function G Figure 4 (f) of the granite structural plane is determined: 2 (f):

[0073] G 2 (f) = 44.09 + ln(12.38·f 2.53 )

[0074] In step S4, the critical shear strength τ of the rock mass structural plane disturbance under the action of the same lateral stress σ, p , amplitude A, frequency f, and different normal stresses σ n is obtained, and the variation law is as c shown. The corresponding model parameter Figure 5 is i = 21.08 MPa. At the same time, the critical shear strength G (σ 3 ) of the granite structural plane disturbance is determined: n )

[0075] G 3 (σ n ) = σ n tan(59.5°) + 21.08

[0076] In step S5, the critical shear strength τ of the rock mass structural plane disturbance under the action of the same normal stress σ, n , amplitude A, frequency f, and different lateral stresses σ p is obtained, and the variation law is as c shown. The corresponding model parameters are l = 35.54 MPa, r = 10.16 MPa, σ Figure 6 ρ = 7.644 MPa, and K = 4.03 MPa. At the same time, the critical shear strength G 4 (σ p ) of the granite structural plane disturbance is determined: )

[0077]

[0078] In step S6, based on the law of the peak shear strength of granite structural planes under different normal stresses, different lateral stresses, different amplitudes, and different frequencies in a three-dimensional stress state, the critical shear strength τ of the granite structural plane under disturbance in the three-dimensional stress state is constructed. c The variation law is obtained, and the corresponding model parameters are b = 81.34 MPa, h = 4.01 MPa, d = 2.53 MPa, r = 1.33 MPa, σ ρ = 7.77 MPa, K = 2.67 MPa, n = 19.36 MPa. The critical shear strength function model G 5 (σ n , σ p , A, f) of the granite structural plane under disturbance in the three-dimensional stress state is constructed, and the envelope surface morphology of the critical shear strength function of the rock mass structural plane is determined as Figure 7 shown as:

[0079]

[0080] In step S7, as Figure 8 shown, a true triaxial disturbance shear test of the rock mass structural plane under combinations of different normal stress σ n , lateral stress σ p , amplitude A, and frequency f different from those in S1 is carried out to obtain the corresponding critical shear strength of the rock mass structural plane under disturbance, verify and improve the critical shear strength function model G 5 (σ n , σ p , A, f) of the rock mass structural plane under disturbance in the three-dimensional stress state, obtain the predicted value τ g of the critical shear strength of the rock mass structural plane under disturbance, as shown in Table 2; calculate the root mean square of the test value τ c and the predicted value τ g of the critical shear strength of the rock mass structural plane under disturbance. Within the error limit, construct the dynamic disturbance failure criterion G(σ n , σ p , A, f) of the rock mass structural plane under true three-dimensional stress.

[0081] Table 1 Critical shear strength of granite under disturbance

[0082]

[0083] Table 2 Test values and predicted values of the critical shear strength of granite under disturbance

[0084]

[0085] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. The construction method of the dynamic disturbance failure criterion of the rock mass structure surface under true three-dimensional stress includes the following steps: S1. Carry out true triaxial perturbation shear test to determine the normal stress σ n and different lateral stresses σ p , Critical shear strength τ of rock mass structural surface disturbance under different amplitudes A and different frequencies f c ; S2. Obtain the same normal stress σ under true triaxial n、 Lateral stressσ p , frequency f and critical shear strength τ of rock mass structural surface disturbance under different amplitudes A c The change law is used to construct the critical shear strength function model G1(A) of the rock mass structural surface disturbance. The method of constructing the critical shear strength function model G1(A) of the rock mass structural surface disturbance is as follows: S2.

1. Construct the normal stress σ under the same three-dimensional stress state based on the perturbation critical shear strength obtained in step S1 n、 Lateral stressσ p , frequency f and critical shear strength τ of rock mass structural surface disturbance under different amplitudes A c Laws of change; S2.

2. Construct the critical shear strength function model G1(A) of rock mass structural surface disturbance: G1(A)=a+b·A α Among them, a, b and α are model parameters; S3. Obtain the same normal stress σ under true triaxial n、 Lateral stressσ p , amplitude A and critical shear strength τ of rock mass structural surface disturbance under different frequencies f c According to the law of change, the critical shear strength function model G2(f) of rock mass structural surface disturbance is constructed. The method of constructing the critical shear strength function model G2(f) of rock mass structural surface disturbance is as follows: S3.

1. Construct the normal stress σ under the same three-dimensional stress state based on the perturbation critical shear strength obtained in step S1 n、 Lateral stressσ p , amplitude A and critical shear strength τ of rock mass structural surface disturbance under different frequencies f c Laws of change; S3.

2. Construct the critical shear strength function model G2(f) of rock mass structural surface disturbance: G2(f)=c+ln(h·f d ) Among them, c, d, and h are model parameters; S4. Obtain the same lateral stress σ under true triaxial p , amplitude A, frequency f and different normal stress σ n Critical shear strength τ of rock mass structural surface disturbance under c The critical shear strength function model G3(σ n ), construct the critical shear strength function model G3(σ n ) is: S4.

1. Construct the same lateral stress σ under the three-dimensional stress state based on the perturbation critical shear strength obtained in step S1 p , amplitude A, frequency f and different normal stress σ n Critical shear strength τ of rock mass structural surface disturbance under c Laws of change; S4.

2. Construct the critical shear strength function model G3(σ n ): in, is the internal friction angle, i is the model parameter; S5. Obtain the same normal stress σ under true triaxial n , amplitude A, frequency f and different lateral stress σ p Critical shear strength τ of rock mass structural surface disturbance under c The critical shear strength function model G4(σ p ), construct the critical shear strength function model G4(σ p ) is: S5.

1. Construct the normal stress σ under the same three-dimensional stress state based on the perturbation critical shear strength obtained in step S1 n , amplitude A, frequency f and different lateral stress σ p Critical shear strength τ of rock mass structural surface disturbance under c Laws of change; S5.

2. Construct the critical shear strength function model G4(σ p ): Among them, l and r are model parameters, σ ρ is the lateral stress corresponding to the maximum rock shear stress, K is the lateral stress with the same strength as the critical shear strength of the disturbance when the lateral stress is 0; S6, based on steps S2 and S3, S4, S5, construct the critical shear strength function model G5 (σ n ,σ p ,A,f), determine the envelope of the critical shear strength function of the rock mass structural surface disturbance, and the method for determining the envelope of the critical shear strength function of the rock mass structural surface disturbance is: S6.

1. Based on the shear peak strength law of rock mass structural surface under different normal stresses, different lateral stresses, different amplitudes, and different frequencies in three-dimensional stress states, the critical shear strength τ of rock mass structural surface disturbance under three-dimensional stress states is constructed. c Laws of change; S6.

2. Construct the critical shear strength function model G5(σ n ,σ p ,A,f): Among them, b, d, h, and r are model parameters, and n is the cohesion; S6.3, according to the constructed rock mass structural surface disturbance critical shear strength function model, determine the envelope shape of the rock mass structural surface disturbance critical shear strength function; S7, develop normal stress σ different from S1 n , lateral stress σ p The true triaxial perturbation shear test of rock mass structure surface under the combination of amplitude A and frequency f is carried out to obtain the corresponding perturbation critical shear strength of rock mass structure surface, and verify and improve the perturbation critical shear strength function model G5(σ n ,σ p ,A,f), characterized by constructing the dynamic disturbance failure criterion G(σ n ,σ p ,A,f) is constructed as follows: S7.

1. Carry out the normal stress σ different from that in S1 n , lateral stress σ p , amplitude A and frequency f, and obtain the corresponding rock mass structural surface disturbance critical shear strength test value τ c ; S7.

2. Replace the normal stress σ in S7.1 with the normal stress σ in S1. n , lateral stress σ p , amplitude A and frequency f are substituted into the critical shear strength function model G5(σ n ,σ p ,A,f), and obtain the predicted value τ of the critical shear strength of the rock mass structural surface disturbance g ; S7.

3. Calculation of the critical shear strength test value τ of the rock mass structural surface disturbance c and the predicted value τ g The root mean square of the rock mass structure surface dynamic disturbance failure criterion G(σ n ,σ p ,A,f): in, is the internal friction angle, σ ρ is the lateral stress corresponding to the maximum shear stress of the rock mass structural surface, K is the lateral stress equal to the critical shear strength of the disturbance when the lateral stress is 0, and P, B, C, and D are model parameters.

2. The dynamic disturbance failure criterion of rock mass structural surface under true three-dimensional stress as claimed in claim 1 is characterized in that: In step S1, different normal stresses σ n and different lateral stresses σ p , true triaxial perturbation shear test under different amplitudes A and different frequencies f, and obtain the corresponding perturbation critical shear strength τ c for: S1.

1. Test data of rock mass structural surface disturbance shear failure under different test conditions obtained through true triaxial disturbance shear test; S1.

2. Take the shear stress and strain at each level under the condition of equal number of cycles and plot τ-ε τ Relationship curve cluster; S1.

3. The shear stress at the inflection point of the curve cluster slope mutation is defined as the perturbation critical shear strength τ c ; S1.

4. Calculate and statistically analyze the critical shear strength of rock mass structural surface disturbance under different test conditions.

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