Rock mass blasting damage and plastic zone analysis method based on Hoek-Brown strength criterion

Abstract

The invention relates to a Hoek-Brown strength criterion-based rock mass blasting damage and plastic zone analysis method, which comprises the following steps: according to a generalized Hoek-Brown strength criterion, carrying out stress calculation on a to-be-analyzed area to obtain an original ground stress; establishing an equilibrium differential equation of radial stress and tangential stress according to elastic mechanics; according to the original crustal stress and the equilibrium differential equation, a plastic zone radius model is obtained through calculation; collecting the acoustic wave velocity of the rock mass in the to-be-analyzed area; and according to the sound wave velocity, calculating through the plastic zone radius model to obtain the plastic zone radius so as to complete rock mass blasting damage and plastic zone analysis. According to the method, the actual state of the rock mass can be reflected more accurately, and the accuracy of plastic zone and explosion damage analysis is improved.

Description

Technical Field

[0001] The invention relates to the technical field of surrounding rock damage zone analysis, and in particular to a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion. Background Art

[0002] At present, blasting construction is still the main excavation method for large-scale geotechnical engineering projects such as mountain tunnels, rock slopes and rock foundations. The shock wave generated at the moment of blasting will not only crush the excavated rock mass, but will inevitably extend the blasting damage to the protected rock mass. The blasting vibration will also cause the opening and sliding of the original cracks in the jointed rock mass. In addition, the stress relaxation and stress concentration caused by excavation will affect the stability development of the surrounding rock. If the additional stress caused by blasting excavation exceeds the strength of the engineering rock mass, it will induce the deterioration of the mechanical properties of the surrounding rock, and then induce surrounding rock damage. We define the surrounding rock damage range outside the contour caused by blasting excavation as the excavation damage zone (EDZ). It is well known that the mechanical parameters of the rock mass within the EDZ are lower than those of ordinary surrounding rocks. Therefore, accurately obtaining the mechanical properties parameters of the rock mass in the EDZ is of great engineering significance for subsequent engineering support and stability evaluation.

[0003] The methods for obtaining rock mechanical parameters mainly include in-situ testing, displacement back analysis method and empirical reduction method. The mechanical performance parameters of rock obtained by large-scale in-situ testing are the most reliable, but the testing cost of this method is high, the cycle is long, and the discreteness of the obtained field data is large. The back analysis method inverts the mechanical parameters of rock by measuring the deformation index of rock, and the application effect of this method is good. However, it is undeniable that the back analysis method requires a large amount of measured deformation data for training, and the feasibility is not high. The empirical reduction method is based on the results of indoor rock tests. By considering the influence of discontinuities, groundwater and size effects, the mechanical parameters of rock are corrected into the performance indicators of rock. Compared with the other two methods, it does not require a large amount of in-situ test data to obtain the mechanical parameters of rock more accurately. Among them, the Hoek-Brown strength criterion comprehensively considers the influence of rock structure and discontinuity conditions, and is one of the most widely used empirical reduction methods. Compared with the Mohr-Coulomb failure criterion, it well explains the failure mode of rock under tensile stress and low stress state, and is more in line with the nonlinear failure characteristics of rock.

[0004] In addition, the Hoek-Brown strength criterion can estimate the deformation of the surrounding rock caused by tunnel excavation. Although this estimation is limited to elastic-plastic rock mass, it can still predict the deformation of the surrounding rock to a certain extent. However, most studies still follow the assumption of E. Hoek, that is, a fixed disturbance factor and mechanical parameters are given to the rock mass in the EDZ area. However, with the increase in the number of blasting excavation and the change in the depth of the surrounding rock, the cumulative damage is a continuously changing physical quantity. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention provides a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion.

[0006] The present invention provides a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion, comprising:

[0007] S1: According to the generalized Hoek-Brown strength criterion, the stress in the analyzed area is calculated to obtain the original ground stress;

[0008] S2: Establish the equilibrium differential equation of radial stress and tangential stress based on elastic mechanics;

[0009] S3: Calculate and obtain a plastic zone radius model according to the original geostress and the equilibrium differential equation;

[0010] S4: Collect the acoustic wave velocity of the rock mass in the area to be analyzed;

[0011] S5: According to the acoustic wave velocity, the plastic zone radius is calculated by the plastic zone radius model to complete the rock mass blasting damage and plastic zone analysis.

[0012] According to a rock blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, the area to be analyzed in step S1 is a circular tunnel. Before stress calculation is performed on the area to be analyzed, assumptions are set, and the assumptions include not taking into account changes in the deadweight of the rock mass and the lateral pressure coefficient being 1.

[0013] According to a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, the expression of the original ground stress corresponding to the microelement in the plastic zone of the area to be analyzed in step S1 is:

[0014]

[0015] Among them, σ θ is the original ground stress, σ r is the radial stress, σ c is the compressive strength of rock mass, m b is the rock mass strength parameter, s is the rock mass disturbance degree parameter, and a is the rock mass disturbance degree constant.

[0016] According to a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, the expression of the equilibrium differential equation in step S2 is:

[0017]

[0018] Where r is the radius component.

[0019] According to a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, step S3 further comprises:

[0020] S31: solving the equilibrium differential equation according to the original geostress to obtain a radius component solution;

[0021] S32: According to the critical radial stress of the elastic-plastic boundary, the radius component solution is converted into a plastic zone radius model.

[0022] According to a rock blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, the expression of the plastic zone radius model in step S3 is:

[0023]

[0024] Among them, r p is the plastic zone radius calculated by the plastic zone radius model, r 0 is the radius of the area to be analyzed, is the critical radial stress of the elastic-plastic boundary, is the critical radial stress at the boundary of the region to be analyzed.

[0025] According to a rock blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, step S5 further comprises:

[0026] S51: Calculate and obtain the geological strength index and the disturbance factor according to the acoustic wave velocity;

[0027] S52: Based on the Hoek-Brown strength criterion, the geological related parameters are calculated according to the geological strength index and the disturbance factor;

[0028] S53: Inputting the geological related parameters into the plastic zone radius model to calculate and obtain the plastic zone radius.

[0029] According to a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, the expression of the geological strength index in step S51 is:

[0030]

[0031] Among them, GSI is the calculated geological strength index, c pis the collected sound wave velocity, RMR 89 A rock mass scoring system.

[0032] According to a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, the expression of the disturbance factor in step S51 is:

[0033]

[0034] Among them, D B is the calculated disturbance factor, c p0 is the acoustic wave test velocity of the undisturbed rock mass.

[0035] According to a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided by the present invention, the geological related parameters in step S52 include:

[0036] Rock mass strength parameter, the expression of the rock mass strength parameter is:

[0037]

[0038] Among them, m b is the rock mass strength parameter, m i It is an indicator of rock quality;

[0039] The rock mass disturbance degree parameter, the expression of the rock mass disturbance degree parameter is:

[0040]

[0041] Among them, s is the parameter of rock mass disturbance degree;

[0042] The rock mass disturbance degree constant, the expression of the rock mass disturbance degree constant is:

[0043]

[0044] Among them, a is the constant of the degree of disturbance of the rock mass.

[0045] The present invention provides a rock blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion. Based on the on-site surrounding rock acoustic wave test results, the EDZ range caused by tunnel excavation and the mechanical properties of the engineering rock mass in the area are determined. Firstly, based on the Hoek-Brown strength criterion and the rock mass classification Q system, the present invention introduces a GSI and DB quantification program, mainly discussing the impact of blasting cumulative damage on the stability of the surrounding rock; then, relying on a specific tunnel project, the variation trend of GSI and DB with the EDZ depth is analyzed, and on this basis, the radius of the tunnel plastic zone under cyclic blasting is estimated, which is of great significance to the subsequent engineering design and adjustment of the construction plan.

[0046] The present invention uses the generalized Hoek-Brown strength criterion for stress calculation, which takes into account various characteristics of the rock mass, such as the strength characteristics of the structural surface, low stress area and tensile stress area, so it can more accurately reflect the actual stress state of the rock mass; the present invention also establishes a balanced differential equation of radial stress and tangential stress, and combines the original ground stress for calculation, so that a more accurate plastic zone radius model can be obtained, thereby improving the accuracy of rock blasting damage and plastic zone analysis; in addition, the present invention uses the acoustic wave velocity, an easily accessible physical quantity, to evaluate the degree of damage to the rock mass, and calculates the plastic zone radius accordingly, avoiding the complex test and measurement process in the traditional method and simplifying the analysis process. In general, the Hoek-Brown strength criterion has been widely used in mining engineering, tunnel engineering, slope stability analysis and other fields. The analysis method proposed by the present invention based on the criterion is also applicable to these fields, and can be appropriately adjusted and optimized according to the specific engineering conditions, so it has strong applicability. The method provided by the present invention can timely discover potential safety hazards, provide a reliable basis for engineering design and construction, and effectively improve the safety of the project.

[0047] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 It is a schematic flow chart of a rock mass blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion provided in an embodiment of the present invention;

[0050] Figure 2 is a schematic diagram of stress analysis of a plastic zone of a tunnel provided by an embodiment of the present invention;

[0051] Figure 3 This is the change in the size of the plastic zone of the tunnel under the cyclic blasting provided by the embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0053] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0054] In order to better understand the present invention, the research background of the present invention is first explained below.

[0055] Compared with single blasting, cyclic blasting causes greater damage to the tunnel surrounding rock. However, current research on blasting damage mainly focuses on tests or projects for single-hole blasting or single blasting, but there are few reports on the cumulative damage of cyclic blasting. In the prior art, a numerical simulation program that can reflect the cumulative damage of cyclic blasting has been developed to obtain the damage PPV threshold of the rock mass, but such an equivalent method is only applicable to specific large-section blasting of tunnels and is not worthy of widespread promotion. Some other prior arts have studied the cumulative blasting damage range of small-clearance tunnels through field measurements and numerical simulation methods. In order to simplify the calculation, they only considered the impact of slot hole blasting, while micro-difference detonation is often used in actual tunnel engineering, that is, each section of blasting will affect the stability of the surrounding rock. Secondly, some other prior arts have developed methods for obtaining surrounding rock parameters suitable for tunnel engineering, but the method of using the rate of change of sound wave velocity as a disturbance factor seems too arbitrary.

[0056] From the above analysis, it can be seen that the research on the cumulative damage of rock mass caused by cyclic blasting is still in its infancy. The plastic zone is the area that should be focused on during tunnel excavation. Accurately and reasonably determining the scope of the plastic zone can provide certain reference significance for the later engineering support methods. At present, most of the research on the plastic zone of the tunnel remains in a fixed scope. However, from the above research results, the present invention finds that cyclic blasting will not only weaken the rock mass properties within the EDZ, but also affect the distribution range of the plastic zone.

[0057] Combine the following Figures 1 to 3 Embodiments of the present invention are described.

[0058] like Figure 1 As shown, the present invention provides a method for analyzing rock blasting damage and plastic zone based on the Hoek-Brown strength criterion, comprising:

[0059] S1: According to the generalized Hoek-Brown strength criterion, the stress of the analyzed area is calculated to obtain the original ground stress.

[0060] Wherein, the area to be analyzed in step S1 is a circular tunnel. Before performing stress calculation on the area to be analyzed, assumptions are set. The assumptions include not taking into account the change in the deadweight of the rock mass and the lateral pressure coefficient being 1.

[0061] like Figure 2 As shown, the present invention takes a deep circular tunnel as an example, and determines the range of the plastic zone under cyclic blasting through elastic-plastic analysis. The specific parameters in the figure are described in the following formula. Before theoretical analysis, some simplified assumptions need to be made. First, the influence of excavation on the deadweight of the rock mass is not considered. Secondly, the theoretical analysis considers the influence of deadweight stress and horizontal stress, assuming that the lateral pressure coefficient λ = 1, that is, the horizontal stress is equal to the vertical stress. Under this assumption, the problem analyzed this time is simplified to a plane strain problem.

[0062] The expression of the original ground stress corresponding to the microelement in the plastic zone of the area to be analyzed in step S1 is:

[0063]

[0064] Among them, σ θ is the original ground stress, σ r is the radial stress, σ c is the compressive strength of rock mass, m b is the rock mass strength parameter, s is the rock mass disturbance degree parameter, and a is the rock mass disturbance degree constant.

[0065] Specifically, the Hoek-Brown strength criterion is proposed based on the Griffith failure criterion, which mainly reflects the nonlinear relationship between the maximum principal stress and the minimum principal stress when the rock fails. The specific expression is as follows.

[0066]

[0067] In the formula, σ 1 and σ 3 They represent the maximum principal stress and minimum principal stress corresponding to the ultimate failure of rock, m i Mainly reflects the quality index of rock, m i ∈[0.001,25],m i It can be obtained through indoor rock uniaxial and triaxial tests by the fitting relationship of the following formula.

[0068]

[0069] Later, E. Hoek improved the criterion and proposed an expression that can be applied to both rocks and rock masses, namely the generalized Hoek-Brown criterion, which is expressed as follows.

[0070]

[0071] r 0 is the tunnel radius, σ 0 is the original ground stress, σ r is the radial stress, σ θ is the tangential stress, and the radius of the plastic zone is r p For any microelement in the plastic zone, σ θ =σ 1 , σ r =σ 3 , then, the above generalized Hoek-Brown criterion can be rewritten to obtain the above original geostress.

[0072] S2: Establish the equilibrium differential equation of radial stress and tangential stress based on elastic mechanics.

[0073] Wherein, the expression of the equilibrium differential equation in step S2 is:

[0074]

[0075] Where r is the radius component.

[0076] S3: According to the original geostress and the equilibrium differential equation, a plastic zone radius model is calculated.

[0077] Wherein, step S3 further comprises:

[0078] S31: Solving the equilibrium differential equation according to the original geostress to obtain a radius component solution.

[0079] S32: According to the critical radial stress of the elastic-plastic boundary, the radius component solution is converted into a plastic zone radius model.

[0080] Wherein, the expression of the plastic zone radius model in step S3 is:

[0081]

[0082] Among them, r p is the plastic zone radius calculated by the plastic zone radius model, r 0 is the radius of the area to be analyzed, is the critical radial stress of the elastic-plastic boundary, is the critical radial stress at the boundary of the region to be analyzed.

[0083] Furthermore, for the above expression of original geostress, let Then the original geostress described in step S1 is transformed into:

[0084]

[0085] After obtaining the expression, the transformation formula of the original geostress and the equilibrium differential equation in step S2 are combined to obtain:

[0086]

[0087] In the formula, H is the coefficient to be determined. 0 , When r = r p When , the radial stress on the elastic-plastic boundary is equal to the tangential stress.

[0088] In addition, through the critical radial stress located at the elastic-plastic boundary, the expression is as follows:

[0089]

[0090] when When , the corresponding microelement is located at the boundary of the plastic zone, so the radius of the plastic zone can be obtained, that is, the expression of the plastic zone radius model mentioned above.

[0091] Since the generalized Hoek-Brown criterion only stipulates two completely extreme rock states, namely undisturbed and completely disturbed, the radius of the plastic zone obtained in this way is not reliable. In addition, the existing improved method does not take the blasting cumulative damage into consideration within the scope of the plastic zone. Therefore, the present invention introduces a method for determining the plastic zone, which has certain advantages.

[0092] The radius of the plastic zone is related to the parameters in the Hoek-Brown criterion, so the GSI and D can be determined based on the longitudinal wave velocity of the rock mass before and after blasting. B , and then determine r through the above plastic zone radius model p size.

[0093] S4: Collect the acoustic wave velocity of the rock mass in the area to be analyzed.

[0094] In step S4, the acoustic wave velocity corresponding to the rock mass is collected before and after the blasting construction.

[0095] S5: According to the acoustic wave velocity, the plastic zone radius is calculated by the plastic zone radius model to complete the rock mass blasting damage and plastic zone analysis.

[0096] Wherein, step S5 further comprises:

[0097] S51: According to the acoustic wave velocity, the geological strength index and the disturbance factor are calculated and obtained respectively.

[0098] The expression of the geological strength index in step S51 is:

[0099]

[0100] Among them, GSI is the calculated geological strength index, c p is the velocity of the collected sound waves, RMR 89 It is a rock mass scoring system proposed in 1989.

[0101] The expression of the disturbance factor in step S51 is:

[0102]

[0103] Among them, D B is the calculated disturbance factor, c p0 is the acoustic wave test velocity of the undisturbed rock mass.

[0104] S52: Based on the Hoek-Brown strength criterion, geological related parameters are calculated according to the geological strength index and the disturbance factor.

[0105] The geological related parameters in step S52 include:

[0106] Rock mass strength parameter, the expression of the rock mass strength parameter is:

[0107]

[0108] Among them, mb is the rock mass strength parameter, m i It is an indicator of rock quality;

[0109] The rock mass disturbance degree parameter, the expression of the rock mass disturbance degree parameter is:

[0110]

[0111] Among them, s is the parameter of rock mass disturbance degree;

[0112] The rock mass disturbance degree constant, the expression of the rock mass disturbance degree constant is:

[0113]

[0114] Among them, a is the constant of the degree of disturbance of the rock mass.

[0115] S53: Inputting the geological related parameters into the plastic zone radius model to calculate and obtain the plastic zone radius.

[0116] In steps S51 to S53, the acquisition result in step S4 is substituted into the expression provided in step S51 to obtain the corresponding geological strength index GSI and the corresponding disturbance factor D B Then, based on the Hoek-Brown criterion, we get the parameter m b , s and a. Finally, the solved parameters are substituted into the plastic zone radius model in step S3 to obtain the plastic zone radius r corresponding to each blasting. p .

[0117] Figure 3 The development of the radius of the plastic zone of the tunnel surrounding rock under five blastings in a specific embodiment is shown. For the measuring points F1 and F2, the radius of the plastic zone r p It increases with the increase of blasting times, and it goes through a process of rapid increase at first and then slow increase. It can be inferred that with the further increase of blasting times, the size of the plastic zone will gradually stabilize, but the cumulative damage of the first few blastings cannot be ignored for the development of the plastic zone.

[0118] The present invention provides a rock blasting damage and plastic zone analysis method based on the Hoek-Brown strength criterion. By introducing the generalized Hoek-Brown strength criterion and combining it with the principle of elastic mechanics, an accurate plastic zone radius model is established. The model not only takes into account the influence of self-weight stress and horizontal stress, but also introduces key parameters such as geological strength index and disturbance factor, so that the actual state of the rock mass can be more accurately reflected and the accuracy of the analysis is improved.

[0119] Secondly, traditional rock blasting damage and plastic zone analysis often require complex experiments and measurements. The present invention collects the easily accessible physical quantity of rock acoustic wave velocity and combines it with the plastic zone radius model for calculation, which greatly simplifies the analysis process and improves work efficiency.

[0120] In addition, the analysis method provided by the present invention is not only applicable to specific engineering structures such as circular tunnels, but can also be appropriately adjusted and optimized according to specific engineering conditions. It is widely used in various rock blasting damage and plastic zone analysis scenarios and has strong applicability.

[0121] Secondly, traditional methods often only consider the two extreme states of undisturbed and fully disturbed when analyzing the plastic zone, ignoring the impact of blasting cumulative damage. The present invention, by introducing parameters such as geological strength index and disturbance factor, can more comprehensively reflect the damage of the rock mass during the blasting process, thereby improving the reliability of the analysis.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for analyzing rock mass blasting damage and plastic zone based on the Hoek-Brown strength criterion, characterized in that: include: S1: According to the generalized Hoek-Brown strength criterion, the stress in the analyzed area is calculated to obtain the original ground stress; S2: Establish the equilibrium differential equation of radial stress and tangential stress based on elastic mechanics; S3: Calculate and obtain a plastic zone radius model according to the original geostress and the equilibrium differential equation; S4: Collect the acoustic wave velocity of the rock mass in the area to be analyzed; S5: According to the acoustic wave velocity, the plastic zone radius is calculated by the plastic zone radius model to complete the rock mass blasting damage and plastic zone analysis.

2. The method for analyzing rock mass blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 1, characterized in that: The area to be analyzed in step S1 is a circular tunnel. Before performing stress calculation on the area to be analyzed, assumptions are set. The assumptions include not taking into account the change in the deadweight of the rock mass and the lateral pressure coefficient being 1.

3. The method for analyzing rock mass blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 1, characterized in that: The expression of the original in-situ stress corresponding to the microelement in the plastic zone of the area to be analyzed in step S1 is: Among them, σ θ is the original ground stress, σ r is the radial stress, σ c is the compressive strength of rock mass, m b is the rock mass strength parameter, s is the rock mass disturbance degree parameter, and a is the rock mass disturbance degree constant.

4. The method for analyzing rock blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 3 is characterized in that: The expression of the equilibrium differential equation in step S2 is: Where r is the radius component.

5. The method for analyzing rock mass blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 1, characterized in that: Step S3 further comprises: S31: solving the equilibrium differential equation according to the original geostress to obtain a radius component solution; S32: According to the critical radial stress of the elastic-plastic boundary, the radius component solution is converted into a plastic zone radius model.

6. The method for analyzing rock blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 3, characterized in that: The expression of the plastic zone radius model in step S3 is: Among them, r p is the radius of the plastic zone obtained by the plastic zone radius model, r0 is the radius of the area to be analyzed, is the critical radial stress of the elastic-plastic boundary, is the critical radial stress at the boundary of the region to be analyzed.

7. The method for analyzing rock blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 1, characterized in that: Step S5 further comprises: S51: Calculate and obtain the geological strength index and the disturbance factor according to the acoustic wave velocity; S52: Based on the Hoek-Brown strength criterion, the geological related parameters are calculated according to the geological strength index and the disturbance factor; S53: Inputting the geological related parameters into the plastic zone radius model to calculate and obtain the plastic zone radius.

8. The method for analyzing rock mass blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 7, characterized in that: The expression of the geological strength index in step S51 is: Among them, GSI is the calculated geological strength index, c p is the collected sound wave velocity, RMR 89 A rock mass scoring system.

9. The method for analyzing rock mass blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 8, characterized in that: The expression of the disturbance factor in step S51 is: Among them, D B is the calculated disturbance factor, c p0 is the acoustic wave test velocity of the undisturbed rock mass.

10. A method for analyzing rock mass blasting damage and plastic zone based on the Hoek-Brown strength criterion according to claim 9, characterized in that: The geological related parameters in step S52 include: Rock mass strength parameter, the expression of the rock mass strength parameter is: Among them, m b is the rock mass strength parameter, m i It is an indicator of rock quality; The rock mass disturbance degree parameter, the expression of the rock mass disturbance degree parameter is: Among them, s is the parameter of rock mass disturbance degree; The rock mass disturbance degree constant, the expression of the rock mass disturbance degree constant is: Among them, a is the constant of the degree of disturbance of the rock mass.

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