A roadway impact hazard assessment method based on energy release intensity

Abstract

The present invention provides a method for evaluating the impact hazard of a roadway based on the energy release intensity, which relates to the technical field of mine safety evaluation. First, according to the physical and mechanical parameters of the surrounding rock of the roadway to be evaluated, the critical elastic energy storage density sum per unit length of the roadway to be evaluated for rock burst occurrence is calculated; and for the roadway to be evaluated, a refined numerical calculation model of the excavation working face is established to calculate the energy density sum accumulated in the surrounding rock of the roadway per unit length; finally, by calculating and comparing the proximity between the energy density sum accumulated in the surrounding rock of the roadway per unit length of the roadway to be evaluated and the critical elastic energy storage density sum per unit length of the roadway to be evaluated for rock burst occurrence, the impact hazard degree and its range of the roadway to be evaluated are determined from the energy perspective. This method evaluates from the energy perspective, and the energy index is more targeted. The evaluation result can truly reflect the actual energy accumulation state of the working face, directly reflects the energy essence of rock burst occurrence, and has a higher accuracy rate.

Description

Technical Field

[0001] The present invention relates to the technical field of mine safety assessment, and particularly relates to a method for evaluating the impact risk of roadways based on the energy release intensity. Background Art

[0002] Roadways are the most important operation, transportation, and pedestrian passageways for ensuring the production of coal mining faces. Therefore, regardless of whether the object to be evaluated is a coal seam, a mining area, or a working face, the essence of the classification and zoning evaluation of rock burst risk is to indicate the possibility level of rock burst occurring after the excavation of roadways in the area to be evaluated and the spatial range of its distribution, that is, the object of impact risk evaluation is all roadways.

[0003] Rock burst is a phenomenon in which the elastic energy accumulated by deep coal and rock masses under high stress is released instantaneously. Therefore, the classification and zoning of impact risk should not only give the evaluation results from the stress perspective, but more importantly, give the evaluation results from the energy perspective to realize the prediction of the intensity of rock burst occurrence, so as to quantitatively serve the roadways anti-burst design link. Currently, the commonly used methods for classifying and zoning the impact risk in coal mines include multi-factor coupling analysis method, multi-factor pattern recognition method, geological dynamic zoning method, possibility index method, etc. These methods focus on the geological condition factors or mining technical factors that cause rock burst, or focus on the internal logical relationship between the influencing factors of rock burst occurrence, revealing the statistical membership relationship, and have strong on-site operability, which is of great significance for the hierarchical prevention and control of rock burst. In recent years, the methods for evaluating the impact risk of coal mines have been continuously developed from qualitative description to quantitative characterization, and from regional overall evaluation to local refined evaluation. Generally, the basic process for establishing a quantitative pre-evaluation method for impact risk is: basic evaluation principle and criterion → evaluation index → classification and quantification interval → evaluation process → practice and verification. It should be emphasized that whether it is the mechanical parameter method or the geophysical method, the core task of constructing the method for classifying and zoning the impact risk of rock burst is to give the theoretical criteria directly quantitatively related to the main control factors of rock burst occurrence from both the stress and energy aspects, so as to obtain a more accurate quantitative evaluation result of the impact risk classification and zoning.

[0004] The Chinese patent with the publication number CN108960653A discloses a multi-scale impact hazard assessment method based on the comprehensive index method. On the basis of the discrete quantitative assessment of the "scoring table" of the old comprehensive index method, considering multi-scale assessment objects comprehensively, new assessment indicators and criteria suitable for the assessment objects are proposed, which improves the pertinence of the assessment objects and the scientificity of the assessment indicators. However, the impact ground pressure influencing factors considered in this method and their values are artificially selected, so the results will be affected by certain human factors to a certain extent. The Chinese patent with the publication number CN110598162A discloses an impact hazard assessment method considering coal seam thickness and coal seam impact tendency. Based on the membership degree statistical mathematical principle, this invention considers the coal seam impact tendency index to quantitatively evaluate the impact hazard, and takes into account the impact of coal seam thickness on the impact. The Chinese patent with the patent number CN201911373903.3 discloses a coal mine impact ground pressure hazard assessment method based on the critical stress index method. Based on the critical stress analytical solution of the "elastic zone - plastic softening zone" roadway impact ground pressure occurrence model, the product of the critical stress and the radius of the critical softening zone is used as an index to evaluate the impact hazard. This invention realizes the quantitative evaluation of the impact hazard based on the strict instability theory. However, this method only gives the impact ground pressure hazard criterion from the stress perspective, and fails to give the hazard of the impact manifestation intensity from the energy perspective.

[0005] In summary, the present invention will propose a roadway impact hazard assessment method based on the energy release intensity from the perspective of the energy generated by the impact ground pressure. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a roadway impact hazard assessment method based on the energy release intensity in view of the deficiencies of the above-mentioned existing technologies. From the aspects of the energy stored in the impact preparation process and the energy density distribution, critical energy indicators and criteria directly related to the main control factors of impact ground pressure (including in-situ stress, coal and rock impact tendency, roadway size, support strength, etc.) are proposed, and combined with the elastic energy evolution state and accumulation degree of the working face, an assessment method that can be directly used to quantitatively divide the impact ground pressure hazard area and indicate the impact ground pressure hazard level is given to guide the design of the impact prevention plan.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is: a roadway impact hazard assessment method based on the energy release intensity. First, according to the physical and mechanical parameters of the surrounding rock of the roadway to be evaluated, calculate the critical elastic energy storage density per unit length of the roadway to be evaluated for impact ground pressure and Π cr ;

[0008] Secondly, for the roadway to be evaluated, establish a refined numerical calculation model of the working face, and calculate the energy density per unit length accumulated in the surrounding rock of the roadway and Π x ;

[0009] Finally, by calculating and comparing the energy density accumulated in the surrounding rock of the roadway to be evaluated per unit length and Π x with the critical elastic energy storage density per unit length of the roadway to be evaluated for rock burst and Π cr of the closeness degree, the rock burst danger degree and its range of the roadway to be evaluated are determined from the energy perspective.

[0010] Specifically, it includes the following steps:

[0011] Step 1: Obtain the rock mechanics parameters of the coal body in the surrounding rock of the roadway to be evaluated; the rock mechanics parameters include the uniaxial compressive strength σ c , elastic modulus E, Poisson's ratio υ, impact modulus index K = λ 1 / E, residual degradation modulus λ 2 and residual strength coefficient ξ; where λ 1 is the post-peak softening modulus;

[0012] Step 2: Calculate the support stress p s according to the roadway support parameters and support forms in the area to be evaluated;

[0013] Step 3: Calculate and optimize the critical ground stress P cr * for the occurrence of rock burst in the roadway to be evaluated;

[0014] The critical ground stress P cr for the occurrence of rock burst in the roadway to be evaluated is shown by the following formula:

[0015]

[0016] where ρ 0 is the roadway radius after the roadway to be evaluated is equivalent to a homogeneous, continuous and isotropic circular roadway; is the internal friction angle of the coal and rock medium in the plastic softening zone, and p fcr is the acting stress of the surrounding rock broken zone on the plastic softening zone when rock burst occurs in the roadway to be pre-warned, as shown by the following formula:

[0017]

[0018] ρ fcr is the critical broken zone radius, as shown by the following formula:

[0019]

[0020] where is the internal friction angle of the coal and rock medium in the broken zone,

[0021] According to the cross-sectional shape of the roadway to be evaluated, the critical ground stress for the occurrence of rock bursts in the roadway to be evaluated is optimized as P cr * = n 1 × P cr ; where P cr * is the critical ground stress for the occurrence of rock bursts in the optimized roadway to be evaluated, and n 1 is the cross-section correction coefficient;

[0022] Step 4: Calculate the critical energy density Π for the occurrence of rock bursts in the roadway to be evaluated cr ;

[0023] Combining the equilibrium differential equation of coal and rock in the elastic zone of the roadway surrounding rock, the geometric equation satisfied by the surrounding rock in the elastic zone, and the constitutive equation satisfied by the surrounding rock in the elastic zone, the strain components in the elastic zone of the surrounding rock are obtained as follows:

[0024]

[0025]

[0026] In the formula, the second term on the right side of the equation is the strain that has occurred under the action of the original rock stress field P before the formation of the roadway. Removing this term, the strain generated by the excavation of the roadway can be obtained as:

[0027]

[0028]

[0029] Among them, ε r is the radial strain of the roadway surrounding rock, and ε θ is the tangential radial strain of the roadway surrounding rock;

[0030] Combining the stress components σ r and σ θ of the surrounding rock of the roadway in the elastic zone:

[0031]

[0032]

[0033] Among them, σ r is the radial stress of the roadway surrounding rock, and σ θ is the tangential radial stress of the roadway surrounding rock;

[0034] Then the strain energy stored in the elastic zone of the surrounding rock per unit length of the roadway is:

[0035]

[0036] Among them, θ is the polar coordinate angle at any position of the roadway surrounding rock;

[0037] At the critical state of roadway rock burst, substituting the radius ρ of the critical plastic softening zone pcr into the above formula, the elastic energy release amount Π per unit length of the roadway when rock burst occurs is obtained cr , as shown in the following formula:

[0038]

[0039] The elastic energy release amount per unit length of the roadway can also be called the critical elastic energy storage density of rock burst occurrence, which expounds the critical energy condition of rock burst occurrence from the perspective of energy, and at the same time characterizes the ability to release elastic energy when roadway rock burst occurs;

[0040] Step 5: Calculate the actual energy density Π of the coal and rock mass per unit length of the roadway to be evaluated x ; According to the actual occurrence environment of the roadway to be evaluated for tunneling or the roadway of the mining face, combined with the basic mechanical parameters and geometric parameters of the coal and rock strata in the strata where the roadway to be evaluated is located, establish a refined numerical model of the mining and excavation face, and calculate the actual energy density distribution curve of the whole roadway during the process of roadway tunneling or working face advancing;

[0041] The actual energy density Π of the coal and rock mass per unit length of the roadway to be evaluated x The calculation formula is:

[0042]

[0043] Among them, σ 1 , σ 2 and σ 3 represent the maximum principal stress, the intermediate principal stress and the minimum principal stress respectively; and are the strains of the coal and rock mass corresponding to σ 1 , σ 2 and σ 3 at the moment to be evaluated;

[0044] Step 6: Calculate the critical energy density index K of the roadway to be evaluated cr , and obtain the critical energy density index distribution curve of the whole roadway established with the mining or excavation layout;

[0045] The critical energy density index K of the roadway to be evaluated cr is as shown in the following formula:

[0046]

[0047] Step 7: According to the critical energy density index K of the roadway to be evaluated cr, determine the impact hazard level of the corresponding area and complete the division of the impact hazard area on the mining engineering plan; when 0 < K cr <0.25, it is evaluated as no impact hazard; when 0.25 ≤ K cr <0.5, it is evaluated as weak impact hazard; when 0.5 ≤ K cr <0.75, it is evaluated as medium impact hazard; when K cr ≥0.75, it is evaluated as strong impact hazard; divide the hazard area for the area to be evaluated according to the hazard level.

[0048] The beneficial effects of the present invention are as follows: A method for evaluating the impact hazard of roadways based on the energy release intensity adopts a method combining theory and actual measurement, and at the same time uses numerical calculation methods to consider the internal relationship between the actual energy density distribution under complex coal seam structures, the impact tendency parameters of coal and rock, the support of coal seam roadways and roadway dimensions, etc., and their main control effects on rock bursts. By analyzing the proximity of the actual coal body energy density state in the mining area to be evaluated to the critical energy density, the impact hazard classification and zoning of the working face are realized. From the perspective of energy, the evaluation energy index is more targeted, and the evaluation results can truly reflect the actual energy accumulation state of the working face, directly reflecting the energy essence of the occurrence of rock bursts, with higher accuracy. Brief Description of the Drawings

[0049] Figure 1 It is a schematic plan projection diagram of the position of the 1208 working face and the surrounding goafs provided by the embodiment of the present invention;

[0050] Figure 2 It is a flow chart of a method for evaluating the impact hazard of roadways based on the energy release intensity provided by the embodiment of the present invention;

[0051] Figure 3 It is the coal-rock constitutive relationship and its simplified model provided by the embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram of the mechanical model for the initiation of roadway rock bursts provided by the embodiment of the present invention;

[0053] Figure 5 It is a schematic diagram of the mining engineering plan of the area to be evaluated provided by the embodiment of the present invention;

[0054] Figure 6 It is a refined numerical model diagram of the 1208 working face provided by the embodiment of the present invention;

[0055] Figure 7 It is a curve diagram of the actual energy density distribution of the roadway with rock bursts provided by the embodiment of the present invention;

[0056] Figure 8Distribution curve of critical energy density index of roadway prone to rock burst provided by the embodiment of the present invention;

[0057] Figure 9 Division result of rock burst danger area based on critical energy density index provided by the embodiment of the present invention. Specific embodiments

[0058] The following combines the drawings and embodiments to further describe in detail the specific embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0059] Taking the 1208 working face of a certain mine as an example, the rock burst danger evaluation method of the roadway based on the energy release intensity of the present invention is used to classify and divide the rock burst danger during the driving process of the return air crossheading of this working face.

[0060] The 1208 working face is as Figure 1 shown. The goaf above is the 704 goaf, 706 goaf, 708 goaf and 710 goaf of No. 7 coal. The distance between No. 7 coal and No. 12 coal is 60 m. One side of the 1208 working face is the 1206 goaf, and the other side is solid coal.

[0061] In this embodiment, a rock burst danger evaluation method of the roadway based on the energy release intensity, as Figure 2 shown, includes the following steps:

[0062] Step 1: Obtain the rock mechanics parameters of the coal body in the surrounding rock of the roadway to be evaluated; the rock mechanics parameters can be defined according to the coal-rock constitutive relationship and its simplified model. As Figure 3 shown, it includes uniaxial compressive strength σ c , elastic modulus E, Poisson's ratio υ, impact modulus index K = λ 1 / E, residual descending modulus λ 2 , residual strength coefficient ξ; where λ 1 is the post-peak softening modulus; calculate the critical conditions of rock burst according to the mechanical model of the initiation of roadway rock burst. The schematic diagram of the model is as Figure 4 shown.

[0063] Step 2: Calculate the support stress p s = 0.69 MPa according to the roadway support parameters and support forms in the area to be evaluated;

[0064] Step 3: Calculate and optimize the critical ground stress P cr * for the occurrence of rock burst in the roadway to be evaluated;

[0065] The critical ground stress P cr for the occurrence of rock burst in the roadway to be evaluated is as shown in the following formula:

[0066]

[0067] Among them, ρ 0 is the roadway radius after equivalenting the roadway to be evaluated into a homogeneous, continuous and isotropic circular roadway; is the internal friction angle of the coal and rock medium in the plastic softening zone, p fcr is the acting stress of the surrounding rock broken zone on the plastic softening zone when rock burst occurs in the roadway to be warned, as shown in the following formula:

[0068]

[0069] ρ fcr is the critical broken zone radius, as shown in the following formula:

[0070]

[0071] Among them, is the internal friction angle of the coal and rock medium in the broken zone,

[0072] According to the cross-sectional shape of the roadway to be evaluated, the critical ground stress for the occurrence of rock burst in the roadway to be evaluated is optimized as P cr * = n 1 × P cr ; Among them, P cr * is the critical ground stress for the occurrence of rock burst in the optimized roadway to be evaluated, n 1 is the cross-section correction coefficient; when the cross-sectional shape of the roadway to be evaluated is rectangular, trapezoidal, straight-wall arched, circular, n 1 takes 0.89, 0.92, 0.95, 0.98 respectively;

[0073] Step 4: Calculate the critical energy density Π for the occurrence of rock burst in the roadway of the working face to be evaluated cr ;

[0074] The equilibrium differential equation of the coal and rock in the elastic zone of the roadway surrounding rock is:

[0075]

[0076] The geometric equation satisfied by the surrounding rock in the elastic zone is:

[0077]

[0078] The constitutive equation satisfied by the surrounding rock in the elastic zone is:

[0079]

[0080] Among them, ν is the Poisson's ratio, ε r is the radial strain of the surrounding rock of the roadway, ε θ is the tangential strain of the surrounding rock of the roadway, u is the displacement of the surrounding rock, r is the polar coordinate radius at any position of the surrounding rock of the roadway, σ r is the radial stress of the surrounding rock of the roadway, σ θ is the tangential stress of the surrounding rock of the roadway;

[0081] Therefore, by combining the equilibrium differential equation of coal and rock in the elastic zone of the surrounding rock of the roadway, the geometric equation satisfied by the surrounding rock in the elastic zone, and the constitutive equation satisfied by the surrounding rock in the elastic zone, the strain components in the elastic zone of the surrounding rock are obtained as:

[0082]

[0083]

[0084] In the formula, the second term on the right side of the equation is the strain that has occurred under the action of the original rock stress field P before the formation of the roadway. Removing this term, the strain generated by the excavation of the roadway can be obtained as:

[0085]

[0086]

[0087] Combining the stress components σ r and σ θ of the surrounding rock in the elastic zone:

[0088]

[0089] Then the strain energy stored in the elastic zone of the surrounding rock per unit length of the roadway is:

[0090]

[0091] Among them, θ is the polar coordinate angle at any position of the surrounding rock of the roadway;

[0092] Furthermore, at the critical state of rock burst in the roadway, substituting the radius ρ pcr of the critical plastic softening zone into the above formula, the elastic energy release amount Π cr per unit length of the roadway during the occurrence of rock burst can be obtained, as shown in the following formula:

[0093]

[0094] The elastic energy release amount Π cr per unit length of this roadway can also be called the critical elastic energy storage density during the occurrence of rock burst. It expounds the critical energy condition for the occurrence of rock burst from the perspective of energy, and at the same time characterizes the ability to release elastic energy during the occurrence of rock burst in the roadway.

[0095] In this embodiment, the critical energy density Π of the roadway rock burst occurring in the working face to be evaluated is calculated cr and the relevant parameter values are shown in Table 1

[0096] Table 1 Parameter values of the critical energy density of the roadway rock burst in the working face to be evaluated and related parameters

[0097]

[0098]

[0099] Step 5: Analyze the actual energy density Π of the coal and rock mass per unit length of the roadway in the area to be evaluated x , and establish the actual energy density distribution curve of the whole roadway with the mining or excavation layout

[0100] In this embodiment, according to the actual working conditions on site of the mine, the mining and excavation engineering plan of the area to be evaluated in the 1208 working face is as Figure 5 shown, and the refined numerical calculation model of the 1208 working face is established as Figure 6 shown. Combining the basic mechanical parameters and geometric parameters of the coal and rock strata in the working face to be evaluated, a refined numerical model of the working face to be evaluated is established, and the actual coal and rock energy density Π is obtained along the roadway to be evaluated x .

[0101] Assign parameters to each coal and rock stratum according to the lithology of the coal and rock, and conduct the initial state balance calculation of the in-situ stress loading. Excavate the working face in sequence according to the actual mining sequence. After the calculation is completed, excavate the 1208 working face step by step. After each excavation is completed, calculate the actual energy density of the whole roadway during the coal face advancing process, and obtain the energy density distribution curve per unit length. Taking the 1208 return airway as an example in this embodiment, the energy density distribution curve per unit length is calculated as Figure 7 shown

[0102] Step 6: Calculate the critical energy density index K of the area to be evaluated cr , and obtain the critical energy density index distribution curve of the whole roadway with the mining or excavation layout

[0103]

[0104] Step 7: Complete the division of the rock burst danger area on the mining and excavation engineering plan, and determine the rock burst danger level of the corresponding area; when 0 < K cr < 0.25, it is evaluated as no rock burst danger; when 0.25 ≤ K cr < 0.5, it is evaluated as weak rock burst danger; when 0.5 ≤ K cr < 0.75, it is evaluated as medium rock burst danger; when K cr≥0.75 is evaluated as a strong impact hazard; the evaluation area is divided into hazard areas according to the hazard level.

[0105] According to the actual energy density Π of the coal and rock mass obtained in step 5 x and the critical energy density Π at which roadway rock bursts occur in step 4 cr , calculate the critical energy density index K of the roadway prone to rock bursts cr distribution curve, as Figure 8 shown. The division result of the impact hazard area based on the critical energy density index is as Figure 9 shown.

[0106] It can be seen from the division result of the impact hazard area based on the critical energy density index that there is a good correspondence between the medium impact hazard area and the strong impact hazard area and the remaining coal pillars of coal seam 7, and there is a good correspondence between the weak impact hazard area and the remaining goafs of coal seam 7, which can further confirm the rationality and effectiveness of the impact hazard area division method provided by the present invention.

[0107] 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 foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope defined by the claims of the present invention.

Claims

1. A method for evaluating the impact risk of roadway based on energy release intensity, characterized in that: According to the physical and mechanical parameters of the surrounding rock of the roadway to be evaluated, calculate the critical energy density and Π of rock burst occurring in the roadway to be evaluated per unit length cr ; For the roadway to be evaluated, a refined numerical calculation model of the excavation and working face is established to calculate the energy density accumulated in the surrounding rock of the roadway per unit length of the roadway to be evaluated and Π x ; By calculating and comparing the energy density accumulated in the surrounding rock of the roadway to be evaluated per unit length of the roadway and Π x with the critical elastic energy storage density and Π for rock burst occurrence in the roadway to be evaluated per unit length cr of the proximity degree, the rock burst danger degree and its range of the roadway to be evaluated are determined from the energy perspective; Specifically, it includes the following steps: Step 1: Obtain the rock mechanics parameters of the coal body in the surrounding rock of the roadway to be evaluated; Step 2: Calculate the support stress p based on the roadway support parameters and support forms in the area to be evaluated s ; Step 3: Calculate and optimize the critical ground stress P for the occurrence of rock burst in the roadway to be evaluated cr * ; Step 4: Calculate the critical energy density and Π of rock burst occurrence in the roadway to be evaluated per unit length cr ; Combining the coal-rock equilibrium differential equation in the elastic zone of the roadway surrounding rock, the geometric equation satisfied by the surrounding rock in the elastic zone, and the constitutive equation satisfied by the surrounding rock in the elastic zone, the strain components in the elastic zone of the surrounding rock are obtained as: where σ c is the uniaxial compressive strength, E is the elastic modulus, ν is the Poisson's ratio, λ 2 is the residual degradation modulus, ξ is the residual strength coefficient, λ 1 is the post-peak softening modulus, is the internal friction angle of the coal and rock medium in the plastic softening zone, r is the polar coordinate radius at any position of the roadway surrounding rock; the second term on the right side of the equation is the strain that has occurred under the action of the original rock stress field P before the roadway is formed. Removing this term gives the strain generated by the roadway excavation as: Among them, ε r is the radial strain of the roadway surrounding rock, and ε θ is the tangential radial strain of the roadway surrounding rock; Combined with the stress components σ r and σ θ : Among them, σ r is the radial stress of the surrounding rock of the roadway, and σ θ is the tangential radial stress of the surrounding rock of the roadway; Then the strain energy Π stored in the elastic zone of the surrounding rock per unit length of the roadway is: where θ is the polar coordinate angle at any position of the roadway surrounding rock; At the critical state of roadway rockburst occurrence, substituting the radius ρ of the critical plastic softening zone pcr into the above formula, the critical energy density of rockburst occurrence per unit length of the roadway to be evaluated and Π cr are obtained as shown in the following formula: Among them, P cr is the critical ground stress for the occurrence of rock burst in the roadway to be evaluated, ρ 0 is the radius of the roadway after equivalenting the roadway to be evaluated into a homogeneous, continuous and isotropic circular roadway, is the internal friction angle of the coal and rock medium in the broken zone; This critical energy density is also called the critical elastic energy storage density for the occurrence of rock burst. It expounds the critical energy condition for the occurrence of rock burst from the perspective of energy, and at the same time characterizes the ability to release elastic energy when the roadway rock burst occurs; Step 5: Calculate the energy density and Π accumulated in the surrounding rock of the roadway per unit length of the roadway to be evaluated x ; According to the actual occurrence environment of the roadway to be evaluated for tunneling or the roadway of the coal mining face, combined with the basic mechanical parameters and geometric parameters of the coal and rock strata in the strata where the roadway to be evaluated is located, establish a refined numerical model of the mining face, and calculate the actual energy density distribution curve of the entire roadway during the roadway tunneling or the face advancing The energy density accumulated in the surrounding rock of the roadway per unit length of the roadway to be evaluated and Π x The calculation formula is as follows: Among them, σ 1 , σ 2 and σ 3 respectively represent the maximum principal stress, the intermediate principal stress, and the minimum principal stress; and are respectively the strains of the coal and rock mass corresponding to σ 1 , σ 2 and σ 3 at the moment to be evaluated; Step 6: Calculate the critical energy density index K of the roadway to be evaluated cr , and obtain the distribution curve of the critical energy density index of the entire roadway established with the mining or excavation layout Critical energy density index K of the roadway to be evaluated cr As shown in the following formula: Step 7: According to the critical energy density index K of the roadway to be evaluated cr , determine the impact hazard level of the corresponding area, and complete the division of the impact hazard area on the mining engineering plan.

2. A method for evaluating the impact risk of roadway based on energy release intensity according to claim 1, characterized in that: The rock mechanical parameters described in Step 1 include the uniaxial compressive strength σ c , elastic modulus E, Poisson's ratio υ, impact modulus index K = λ 1 / E, residual degradation modulus λ 2 and residual strength coefficient ξ; where λ 1 is the post-peak softening modulus.

3. A method for evaluating the impact risk of roadway based on energy release intensity according to claim 2, characterized in that: The specific method of step 3 is: The critical ground stress P for the occurrence of rock burst in the roadway to be evaluated cr As shown in the following formula: where ρ 0 is the radius of the roadway after equivalent transformation of the roadway to be evaluated into a homogeneous, continuous and isotropic circular roadway; is the internal friction angle of the coal and rock medium in the plastic softening zone, and p fcr is the acting stress of the surrounding rock broken zone on the plastic softening zone when rock burst occurs in the roadway to be pre-warned, as shown in the following formula: ρ fcr is the critical fracture zone radius, as shown in the following formula: Among them, is the internal friction angle of the coal and rock medium in the broken zone, According to the cross-sectional shape of the roadway to be evaluated, the critical ground stress for the occurrence of rockburst in the roadway to be evaluated is optimized to be P cr * = n 1 ×P cr ; where P cr * is the critical ground stress for the occurrence of rockburst in the optimized roadway to be evaluated, and n 1 is the cross-section correction coefficient.

4. A method for evaluating the impact risk of roadway based on energy release intensity according to claim 3, characterized in that: When 0 < K cr < 0.25, it is evaluated as having no impact danger; when 0.25 ≤ K cr < 0.5, it is evaluated as having weak impact danger; when 0.5 ≤ K cr < 0.75, it is evaluated as having medium impact danger; when K cr ≥ 0.75, it is evaluated as having strong impact danger; the danger area division is carried out for the area to be evaluated according to the danger level.

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