Method for identifying rockburst-collapse composite disaster area of deep-buried tunnel

Abstract

The invention discloses a deep-buried tunnel rockburst-collapse composite disaster area identification method, which comprises the following steps: S1, obtaining a collapse tendency evaluation index based on passive source tendency evaluation of a rock mass basic quality grading index; s2, judging whether a transition section of a fractured rock mass and a complete rock mass exists or not according to geological conditions of the evaluation area, and correcting ground stress; s3, performing active source tendency evaluation based on a rock mass strength-stress ratio to obtain a rockburst tendency evaluation index; s4, identifying a potential rockburst-collapse composite disaster area and a rockburst or collapse single disaster type disaster area according to the rock mass quality grade value and the rock mass strength-stress ratio; according to the method, the deep-buried tunnel rockburst-collapse composite disaster area is identified based on the rock mass quality grade and the rock mass strength-stress ratio, and a scientific disaster area identification basis is provided for deep underground engineering with strong tectonic stress and large stratum variability.

Description

Technical Field

[0001] This application relates to the technical field of geomechanics, and particularly to a method for identifying the compound disaster area of rockburst - collapse in deep - buried tunnels. Background Technique

[0002] Under the conditions of high in - situ stress in deep - buried highlands with large formation variability and complex geological structures, compound disasters of rockburst - collapse frequently occur during the excavation of underground projects. This has become the main bottleneck problem in the current construction of deep - buried underground projects, and its harm degree far exceeds that of single - disaster types such as rockburst or collapse. In the existing technology, in order to accurately predict rockburst or collapse, for rockburst risk assessment, in - situ testing methods such as microseismic monitoring and empirical criteria such as elastic strain energy index have been proposed. For collapse risk assessment, an analysis method based on deep - learning algorithms has been proposed. Although the above - mentioned methods are relatively mature and perfect in the early warning of single - disaster types of rockburst or collapse, in actual engineering, the occurrence of disasters is often comprehensively affected by various factors such as structural planes, groundwater, and in - situ stress. The existence of these factors leads to significant differences between the mechanical parameters of rock masses and intact rocks, increasing the complexity of disaster prediction. In addition, the characteristics of rockburst - collapse compound disasters further highlight the limitations of existing prediction methods. Such disasters are induced by high - energy fractures in deep intact rock masses, resulting in face collapses, and they have extremely strong suddenness. Due to the great difficulty in identifying active sources in deep rock masses, microseismic monitoring has certain deficiencies in capturing precursor signals of deep rockburst - collapse compound disasters. At the same time, existing research on collapses is mostly based on soft - rock projects and lacks targeted analysis for deep projects with large formation variability. These problems highlight the importance of accurately obtaining rock mass mechanical parameters under complex geological conditions and the key role of comprehensively considering influencing factors such as structural planes in the prediction of compound disasters. Summary of the Invention

[0003] In order to solve the above problems, this application provides a method for identifying the compound disaster area of rockburst - collapse in deep - buried tunnels based on the rock mass quality grade and the rock mass strength - stress ratio, providing a scientific basis for identifying disaster areas for deep underground projects with strong tectonic stress and large formation variability. The technical solution is as follows:

[0004] This application provides a method for identifying the compound disaster area of rockburst - collapse in deep - buried tunnels, including the following steps: S1 Passive - source tendency assessment based on the basic rock mass quality classification index to obtain the collapse tendency evaluation index; S2 According to the geological conditions of the evaluation area, judge whether there is a transition section between fractured rock masses and intact rock masses, and correct the in - situ stress; S3 Active - source tendency assessment based on the rock mass strength - stress ratio to obtain the rockburst tendency evaluation index; S4 Identify potential rockburst - collapse compound disaster areas and single - disaster areas of rockburst or collapse according to the rock mass quality grade value and the rock mass strength - stress ratio.

[0005] For example, in the method for identifying the rockburst-collapse composite disaster area of a deep-buried tunnel provided in an embodiment, the specific steps of S1 are as follows:

[0006] S1.1 Through the preliminary evaluation of rock mass mechanical parameters, the natural quality grade of the rock mass is quantified by the following formula:

[0007] BQ = 90 + 3σ ci + 250K V

[0008] where BQ is the basic quality classification of the rock mass, σ ci is the uniaxial compressive strength of the rock, and K V is the rock mass integrity coefficient;

[0009] S1.2 Modify the rock mass quality, and calculate the quality grade of the engineering rock mass by the following formula:

[0010] [BQ] = BQ - 100(K 1 + K 2 + K 3 )

[0011] where [BQ] is the quality grade of the engineering rock mass, and K 1 ~K 3 represent the groundwater influence correction coefficient, the main weak structural plane attitude influence correction coefficient, and the initial stress state influence correction coefficient respectively.

[0012] For example, in the method for identifying the rockburst-collapse composite disaster area of a deep-buried tunnel provided in an embodiment, in S1.1, the rock mass integrity coefficient K is calculated by the following formula V :

[0013]

[0014] where V pm is the rock mass acoustic wave velocity, V pr is the rock acoustic wave velocity, and the deep rock mass acoustic wave velocity is calculated by the following formula:

[0015]

[0016] where p is the seismic longitudinal wave velocity.

[0017] For example, in the method for identifying the rockburst-collapse composite disaster area of a deep-buried tunnel provided in an embodiment, in S1, the collapse tendency evaluation index based on the quality grade [BQ] of the engineering rock mass is:

[0018] When [BQ] < 250, the rock mass quality level is grade V, and the rock mass is extremely broken;

[0019] When 251 < [BQ] < 350, the rock mass quality level is Class IV, and the rock mass is fractured;

[0020] When 351 < [BQ] < 450, the rock mass quality level is Class III, and the rock mass is moderately fractured;

[0021] When 451 < [BQ] < 550, the rock mass quality level is Class II, and the rock mass is moderately intact;

[0022] When [BQ] > 550, the rock mass quality level is Class I, and the rock mass is intact.

[0023] For example, in the method for identifying the rockburst - collapse composite disaster area of the deep - buried tunnel provided in an embodiment, in S2, an interlayer model is introduced to calculate the stress concentration degree between the fractured rock layer and the intact rock layer, and the magnitude of the internal stress component of the intact rock layer is calculated based on the stress component in the fractured rock layer to correct the in - situ stress and obtain the corrected in - situ stress value σ'. 1 .

[0024] For example, in the method for identifying the rockburst - collapse composite disaster area of the deep - buried tunnel provided in an embodiment, in S3, the rock mass strength is estimated according to the following formula:

[0025] σ cm = σ ci ×S a

[0026] Where, σ cm is the rock mass strength, σ ci is the uniaxial compressive strength of the rock, and S and a are material parameters related to the rock mass characteristics, which are calculated by the following formula:

[0027]

[0028] Where, GS I is the geological strength index of the rock mass, and D is the disturbance factor.

[0029] For example, in the method for identifying the rockburst - collapse composite disaster area of the deep - buried tunnel provided in an embodiment, in S3, the value of GS I is calculated according to the following formula:

[0030] When RMR 76 > 18,

[0031]

[0032] Where, RMR 76 is the rock mass geomechanics classification index of the 1976 version, and the calculation method of the rock mass strength - stress ratio satisfies the following formula:

[0033]

[0034] For example, in the method for identifying the rockburst-collapse composite disaster area provided in an embodiment, in step S3, the rockburst proneness evaluation index based on the rock mass strength-stress ratio is as follows:

[0035] When σ cm / σ 1 < 0.07, it is a strong rockburst;

[0036] When 0.07 < σ cm / σ 1 < 0.15, it is a medium rockburst;

[0037] When 0.15 < σ cm / σ 1 < 0.2, it is a slight rockburst;

[0038] When σ cm / σ 1 > 0.2, there is no rockburst.

[0039] For example, in the method for identifying the rockburst-collapse composite disaster area provided in an embodiment, step S4 is specifically as follows:

[0040] Divide the area with [BQ] < 250 at the tunnel face into the collapse disaster area;

[0041] Divide the area with 251 < [BQ] < 250 at the tunnel face and σ cm / σ 1 < 0.15 or σ cm / σ' 1 < 0.15 into the rockburst-collapse composite disaster area;

[0042] Divide the area with 251 < [BQ] < 250 at the tunnel face and σ cm / σ 1 > 0.15 or σ cm / σ' 1 > 0.15 into the collapse disaster area;

[0043] Divide the area with [BQ] > 350 into the rockburst disaster area.

[0044] The beneficial effects brought by a method for identifying the composite disaster area of rockburst and collapse in deep-buried tunnels provided by some embodiments of this application are as follows: This application focuses on solving the problem of frequent occurrence of composite disasters of rockburst and collapse during the excavation of underground engineering under the conditions of high in-situ stress in deep-buried areas; by proposing an index system based on the identification of potential composite disaster areas in sections, it effectively identifies potential disaster areas and improves the accuracy of disaster prediction; through the seismic longitudinal wave velocity data obtained by the tunnel seismic wave reflection method (TSP), combined with the rock mass quality grade (BQ) and geological strength index (GSI) of the tunnel face, this index system can effectively evaluate the tendency of shallow rock mass collapse and deep rock mass rupture, and solves the problem of how to comprehensively consider the quality, strength and stress state of rock mass for accurate disaster risk assessment under complex geological conditions. Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0046] Figure 1 It is a flow chart of the method for identifying the composite disaster area of rockburst and collapse in deep-buried tunnels of this application. Detailed Embodiments

[0047] The following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0048] Unless otherwise defined, the technical terms or scientific terms used in this disclosure should have the ordinary meaning understood by those of ordinary skill in the field to which this disclosure belongs. The "first", "second" and similar terms used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. "Connection" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0049] Based on the empirical relationship between rock masses and rock mass materials, this application proposes a method for identifying potential rockburst-collapse composite disaster areas based on the rock mass quality grade and the rock mass strength-stress ratio, providing a scientific basis for disaster area identification in deep underground engineering with strong tectonic stress and large formation variability, such as Figure 1 shown, and includes the following steps:

[0050] S1 Passive source tendency assessment based on the basic rock mass quality classification index to obtain the collapse tendency evaluation index;

[0051] Specifically, in the assessment of the collapse tendency of shallow rock masses (passive sources): The rock mass quality grade classification system is a comprehensive rock mass quality assessment method that can quantify the influence of the inherent geological characteristics of rock masses and external environmental factors, and is widely used in the classification of engineering rock mass quality and disaster risk prediction. Its classification process is divided into the following two steps:

[0052] The first step is the basic rock mass quality classification. This step is based on the inherent geological properties of the rock mass itself, independent of the engineering environment, and focuses on evaluating the uniaxial compressive strength (UCS) of the rock and the rock mass integrity coefficient (RQD). This stage aims to quantify the natural quality grade of the rock mass through the preliminary evaluation of rock mass mechanical parameters;

[0053] The second step is to correct the rock mass quality. That is, on the basis of the preliminary classification, further consider the influence of external environmental factors such as groundwater, structural plane characteristics and in-situ stress conditions, and correct the BQ value. This correction process reflects the comprehensive stability of the rock mass under actual engineering conditions, so as to more accurately evaluate the quality grade of the rock mass.

[0054] The basic rock mass quality classification index is as follows:

[0055] BQ = 90 + 3σ ci + 250K V Equation (1);

[0056] where BQ is the basic rock mass quality classification, σ ci is the uniaxial compressive strength of the rock, and K V is the rock mass integrity coefficient;

[0057] The rock mass integrity coefficient K in Equation (1) V is calculated from the acoustic wave velocities of the rock mass and the intact rock. The calculation method is shown in Equation (2). However, it is difficult to obtain the acoustic wave velocity of deep rock masses, and the acoustic wave velocity value of deep rock masses can be obtained through the conversion formula of seismic waves and acoustic waves, as shown in Equation (3):

[0058]

[0059] where V pmis the wave velocity of rock mass acoustic wave, V pr is the wave velocity of rock acoustic wave. The wave velocity of deep rock mass acoustic wave is calculated by the following formula:

[0060]

[0061] where C p is the wave velocity of longitudinal seismic wave.

[0062] The wave velocity of longitudinal seismic wave can be obtained by the Tunnel Seismic Prediction (TSP) method. TSP detects by arranging excitation holes on the side wall near the tunnel face and artificially exciting seismic waves. Its basic operation and principle are as follows: The seismic waves generated by artificial excitation propagate to the tunnel surrounding rock in the form of spherical waves. When the seismic waves encounter an area where the wave impedance of the surrounding rock medium changes (such as karst, fault, or rock layer interface), part of the seismic waves is reflected back, and the other part continues to propagate forward. The reflected seismic waves are received by highly sensitive seismic detectors arranged on the tunnel side wall and transmitted to the host recording device through data. The host converts the reflected wave signal into a seismic wave recording image. By analyzing the seismic wave velocity and the reflected signal, the wave impedance characteristics and medium changes of the surrounding rock can be judged, and then potential geological problem areas (such as karst, fault, or fractured zone) can be identified. The change in wave velocity can also reflect the mechanical state of the surrounding rock, providing a scientific basis for engineering stability evaluation.

[0063] After obtaining the basic quality classification index BQ of the rock mass, the quality grade [BQ] of the engineering rock mass is calculated by the following formula:

[0064] [BQ] = BQ - 100(K 1 + K 2 + K 3 ) Formula (4);

[0065] where [BQ] is the quality grade of the engineering rock mass, and K 1 ~K 3 represent the correction coefficient of groundwater influence, the correction coefficient of the occurrence of main weak structural planes, and the correction coefficient of the initial stress state respectively, and can be determined through Tables 1 - 3 below:

[0066] Table 1 Correction coefficient of groundwater influence K 1 Value

[0067]

[0068] Table 2 Correction coefficient of the occurrence of main weak structural planes K 2 Value

[0069]

[0070] Table 3 Influence correction coefficient K of initial stress state 3 Value taken

[0071]

[0072] The evaluation index of collapse tendency according to the engineering rock mass quality grade [BQ] is shown in Table 4 below:

[0073] Table 4 [BQ] grading standard

[0074]

[0075] According to Equation (4) and Table 4, the surrounding rock grade can be obtained. Generally, it is considered that there is a risk of collapse when the surrounding rock grade is IV and V.

[0076] S2 For the geological conditions of the evaluation area, judge whether there is a transition section between fractured rock mass and intact rock mass, and correct the in-situ stress;

[0077] Specifically, the in-situ stress correction of intact rock mass: In strata with significant differences in rock mass integrity, there are often significant differences in the magnitude and direction of internal stresses in the fractured section and the intact section of the rock mass. Usually, it is manifested as the transfer and concentration of stress to the intact rock mass, while the fractured section of the rock mass shows a certain degree of stress release due to structural damage and deformation characteristics. This stress distribution difference is mainly affected by factors such as pore pressure, rock mass strength, and Young's modulus. Therefore, when identifying potential compound disaster areas, if there are tunnel sections with large differences in rock mass integrity in the area, special attention should be paid to the influence of stress concentration to improve the accuracy of the active source tendency assessment. For this reason, an interlayer model is introduced to calculate the stress concentration degree between the fractured rock layer and the intact rock layer through theoretical analysis. This method calculates the magnitude of the internal stress component of the intact rock layer based on the stress components in the fractured rock layer and provides a quantitative stress concentration degree calculation formula to correct the in-situ stress and obtain the corrected in-situ stress value σ'. 1 , The formula is as follows:

[0078]

[0079] Among them, the superscript of the stress component represents the rock mass type, where I represents the intact rock mass, F represents the fractured rock mass, and σ, E, μ, τ represent normal stress, Young's modulus, Poisson's ratio, and shear stress respectively.

[0080] S3 Based on the active source tendency assessment of the rock mass strength-stress ratio, obtain the rockburst tendency evaluation index;

[0081] Specifically, the evaluation of the tendency of deep rock mass fracture (active source): The rock mass strength can be estimated according to the Hoek-Brown failure criterion:

[0082] σcm = σ ci × S a Equation (11);

[0083] Where, σ cm is the rock mass strength, σ ci is the uniaxial compressive strength of the rock, S and a are material parameters related to the characteristics of the rock mass, and are calculated by the following formula:

[0084]

[0085] Where, GSI is the geological strength index of the rock mass, and D is the disturbance factor.

[0086] Considering that determining the geological strength index (GSI) of the rock mass by the look-up table method has certain subjectivity and cannot accurately evaluate the GSI value of the deep rock mass in front of the tunnel face, this method has certain limitations in practical applications. This application refers to the conversion relationship between the rock mass modulus and RMR 76 (Equation 14) and the relationship between the longitudinal wave of the rock mass and the deformation modulus of the rock mass (Equation 15):

[0087]

[0088] Where, E m is the rock mass modulus, with the unit of GPa; RMR 76 is the rock mass geomechanics classification index of the 1976 version; Cp is the seismic longitudinal wave velocity, with the unit of Km / s;

[0089] When RMR 76 > 18, GSI can be used to represent the RMR value. Combining Equation (14) and Equation (15), we have:

[0090]

[0091] It should be noted that the active source considered in this application is the fracture generated in the intact rock mass in front of the tunnel face, and the deep rock mass is not affected by the excavation blasting. Therefore, the disturbance factor D = 0.

[0092] Substituting Equations (12) - (16) into Equation (11), the calculation formula for the rock mass strength can be obtained as follows:

[0093]

[0094] After obtaining the rock mass strength, the rockburst proneness of the deep rock mass can be judged by the rock mass strength - stress ratio and in combination with the threshold value corresponding to Table 6 below:

[0095]

[0096] Table 6 Rockburst proneness evaluation index based on the ratio of rock mass strength to maximum in-situ stress

[0097] Index No rock burst Minor rock burst Moderate rock burst Severe rock burst <![CDATA[σ cm / σ 1 > >0.2 0.15～0.2 0.07～0.15 <0.07

[0098] S4 Identifies potential rockburst-collapse composite disaster areas and single-disaster areas of rockburst or collapse according to the rock mass quality grade value and the rock mass strength-stress ratio.

[0099] Specifically: After obtaining the proneness evaluation criteria for the active source and the passive source respectively, the corresponding grading situations can be obtained through Table 4 and Table 6.

[0100] When the tunnel face [BQ] < 250, it indicates that the surrounding rock quality is extremely poor (Grade V surrounding rock). Under high in-situ stress conditions, the rock mass is already in a broken state and difficult to maintain stability. At this time, even without external disturbances, the surrounding rock has reached the critical condition for collapse. Therefore, the area with [BQ] < 250 is divided into the area where collapse disasters may occur;

[0101] When 251 < [BQ] < 350 for the tunnel face, the surrounding rock quality is Grade IV. The surrounding rock of the tunnel face can basically maintain self-stability under high in-situ stress conditions, but its stability is sensitive to external disturbances. At this time, it is necessary to further divide according to the proneness evaluation results of the active source:

[0102] When the proneness evaluation result of the active source is medium or higher rockburst, that is: σ cm / σ 1 <0.15 or σ cm / σ' 1 <0.15, it indicates that there are large-energy fracture events in the deep rock mass, and the energy released by them will induce rockburst-collapse composite disasters through the action of vibration waves. Therefore, the area with BQ value between 250 and 350 and the proneness evaluation result of the active source being medium or higher rockburst is divided into the composite disaster area;

[0103] When the proneness evaluation result of the active source is slight rockburst or no rockburst, that is: σ cm / σ 1 >0.15 or σ cm / σ' 1 >0.15, it indicates that only small-energy fracture events occur in the deep rock mass. Although the vibration waves generated by the fractures will deteriorate the surrounding rock of the tunnel face, due to the small energy, no rock block ejection phenomenon will be induced. Therefore, the area with BQ value between 250 and 350 and the proneness evaluation result of the active source being slight rockburst or no rockburst is divided into the collapse area.

[0104] When [BQ] > 350, it indicates that the surrounding rock of the tunnel face is intact and can resist cave - ins. However, rock bursts may still occur under high in - situ stress conditions. At this time, the tendency of cave - ins does not need to be considered, but the rock burst disaster needs to be warned through on - site micro - seismic monitoring. Therefore, the area with BQ value greater than 350 is classified as the rock burst disaster area.

[0105] The index system proposed in this application not only considers two single disaster types, namely rock bursts and cave - ins, but also takes the compound disaster of rock bursts and cave - ins as the research focus, comprehensively considering various factors such as geological variability, in - situ stress, and rock mass quality. This enables it to more accurately identify potential compound disaster areas under complex geological conditions. Through the longitudinal seismic wave velocity obtained by the tunnel seismic wave reflection method (TSP), this application can accurately evaluate the rock mass quality grade (BQ) and geological strength index (GSI), and combine the rock mass quality with the rock mass strength - stress ratio to identify the disaster tendency. Compared with the traditional single prediction methods for rock bursts or cave - ins, the method of this application adds a new measurement dimension, improving the reliability and accuracy of disaster prediction.

[0106] Based on the rock mass quality and geological strength index of the tunnel face, this application proposes a compound disaster tendency evaluation index for a 10 - meter tunnel section, which can accurately classify the disaster types and provide a basis for early warning. Compared with the traditional single - disaster prediction methods, the early - warning method of this application is not only highly targeted but also able to identify more potential risks. When studying the mechanism of rock burst - cave - in compound disasters, this application deeply analyzes the critical state of rock mass instability and proposes the whole process of rock burst - cave - in caused by rock mass rupture. Compared with the previous single - disaster studies, this application makes a more comprehensive discussion on the analysis of disaster mechanisms, helping to better understand the internal causes and prediction methods of compound disasters.

[0107] Although the implementation scheme of this application has been disclosed as above, it is not limited to the applications listed in the specification and implementation methods. It can be fully applied to various fields suitable for this application. For those familiar with this field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalent scope, this application is not limited to specific details and the examples shown and described here.

Claims

1. A method for identifying rockburst-collapse complex disaster areas in deep tunnels, characterized in that: The following steps are involved: S1 passive source tendency assessment based on basic rock mass quality classification indicators to obtain collapse tendency evaluation indicators; S2 determines whether there is a transition section between broken rock mass and intact rock mass according to the geological conditions of the assessment area, and corrects the ground stress; S3 evaluates the active source tendency based on the rock mass strength-stress ratio to obtain the rockburst tendency evaluation index; S4 identifies potential rockburst-landslide combined disaster areas and rockburst or landslide single disaster areas based on rock mass quality grade value and rock mass strength stress ratio.

2. The method for identifying the rockburst-collapse complex disaster area in a deep tunnel according to claim 1, characterized in that: The step S1 is specifically as follows: S1.1 Through preliminary assessment of rock mass mechanical parameters, the natural quality grade of the rock mass is quantified by the following formula: BQ=90+3σ ci +250K V Among them, BQ is the basic quality classification of rock mass, σ ci is the uniaxial compressive strength of rock, K V is the rock mass integrity coefficient; S1.2 The rock mass quality is corrected and the quality grade of the engineering rock mass is calculated by the following formula: [BQ] = BQ - 100 (K1 + K2 + K3) Among them, [BQ] is the engineering rock mass quality grade, K1~K3 represent the correction factor of groundwater influence, the correction factor of main weak structural surface attitude influence and the correction factor of initial stress state influence, respectively.

3. The method for identifying the rockburst-collapse complex disaster area in a deep tunnel according to claim 2, characterized in that: In S1.1, the rock mass integrity factor K is calculated by the following formula: V : Among them, V pm is the velocity of the rock mass sound wave, V pr is the acoustic wave velocity of rock, and the acoustic wave velocity of deep rock mass is calculated according to the following formula: Among them, C p is the velocity of the seismic longitudinal wave.

4. The method for identifying the rockburst-collapse complex disaster area in a deep tunnel according to claim 3, characterized in that: In S1, the collapse tendency evaluation index according to the engineering rock mass quality grade [BQ] is: When [BQ] < 250, the rock mass quality level is V, and the rock mass is extremely broken; When 251<[BQ]<350, the rock mass quality level is IV, and the rock mass is broken; When 351<[BQ]<450, the rock mass quality level is Grade III, and the rock mass is relatively broken; When 451<[BQ]<550, the rock mass quality level is Grade II, and the rock mass is relatively intact; When [BQ]>550, the rock quality level is Grade I and the rock mass is intact.

5. The method for identifying the rockburst-collapse complex disaster area in a deep tunnel according to claim 4, characterized in that: In S2, an interlayer model is introduced to calculate the stress concentration degree between the broken rock layer and the intact rock layer, and the value of the stress component inside the intact rock layer is calculated based on the stress component in the broken rock layer to correct the ground stress and obtain the corrected ground stress value σ'1.

6. The method for identifying the rockburst-collapse complex disaster area in a deep tunnel according to claim 5, characterized in that: In S3, the rock mass strength is estimated according to the following formula: s cm =s ci ×S a Among them, σ cm is the rock mass strength, σ ci is the uniaxial compressive strength of rock, S and a are material parameters related to rock mass properties, calculated by the following formula: Among them, GSI is the rock geological strength index, and D is the disturbance factor.

7. The method for identifying the rockburst-collapse complex disaster area in a deep tunnel according to claim 6, characterized in that: In S3, the value of GSI is calculated according to the following formula: When RMR 76 >18:00, Among them, RMR 76 The 1976 version of the rock mass geomechanics classification index, the calculation method of the rock mass strength-stress ratio satisfies the following formula:

8. The method for identifying the rockburst-collapse complex disaster area in a deep tunnel according to claim 7, characterized in that: In S3, the rockburst tendency evaluation index based on the rock mass strength-stress ratio is: When σ cm When / σ1<0.07, it is a strong rock burst; When 0.07<σ cm When / σ1<0.15, it is a moderate rock burst; When 0.15<σ cm When / σ1<0.2, it is a slight rock burst; When σ cm When / σ1>0.2, there is no rock burst.

9. The method for identifying the rockburst-collapse complex disaster area in a deep tunnel according to claim 8, characterized in that: The step S4 is specifically as follows: The area with tunnel face [BQ] < 250 is classified as landslide hazard area; The tunnel face 251<[BQ]<250, and σ cm / σ1<0.15orσ cm The area with / σ'1<0.15 is classified as the rockburst-landslide compound disaster area; The tunnel face 251<[BQ]<250, and σ cm / σ1>0.15 or σ cm The area with / σ'1>0.15 is classified as landslide hazard area; The area with [BQ]>350 is classified as rock burst hazard area.

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