Selection method of anti-bumping support for roadway with rock burst based on support strength

Abstract

The present invention relates to the technical field of roadway support, and discloses a method for selecting an anti-bumping support for a bump-prone roadway based on the support strength. The method for determining the support strength includes: determining a first equivalent ground stress of a roadway in the mining influence area; determining a surrounding rock-support interaction equilibrium curve under the first equivalent ground stress according to the system equation of the roadway, the displacement of the surrounding rock of the roadway, the first equivalent ground stress, and the first boundary stress of the broken zone on the softened zone; and determining the support strength of the hydraulic support to be selected for the surrounding rock according to the support balance point on the interaction equilibrium curve and the stress of the bolt support of the roadway. The present invention quantitatively determines the deformation coordination response and the interaction equilibrium relationship between the "surrounding rock and the support" of the bump-prone roadway, thereby accurately determining the support strength of the hydraulic support to be selected for the surrounding rock, and further realizing the parametric selection of the anti-bumping hydraulic support for the roadway.

Description

Technical Field

[0001] The present invention relates to the technical field of roadway support, and particularly to a method for selecting an impact pressure prevention support for a roadway with rock bursts based on support strength. Background Art

[0002] Rock burst is one of the serious dynamic disasters in coal mines and is a world-class problem jointly faced by the current rock mechanics community and mining community. Looking at the entire physical process of rock burst disasters, although a rock burst is often completed instantaneously in the millisecond to second range, it can still be divided into a gestation stage before the impact initiation point and a destruction stage after the impact initiation point. However, existing roadway support design methods and equipment selection methods do not fully consider the loading effect of the working face mining on the advanced roadway, nor can they quantitatively analyze the mutual feedback equilibrium state between the surrounding rock and the support of a roadway with rock bursts, and even less can they accurately select an impact pressure prevention support equipment based on the support strength. Summary of the Invention

[0003] The object of the present invention is to provide a method for selecting an impact pressure prevention support for a roadway with rock bursts based on support strength, which considers the loading effect of the working face mining on the advanced roadway, can quantitatively determine the deformation coordination response and mutual feedback equilibrium relationship between the "surrounding rock and the support" of a roadway with rock bursts, thereby accurately determining the support strength of the hydraulic support to be selected for the surrounding rock, and further realizing the parametric selection of the impact pressure prevention hydraulic support for the roadway based on the support strength.

[0004] To achieve the above object, in a first aspect of the present invention, a method for determining support strength is provided. The determination method includes: determining a first equivalent ground stress of a roadway in the mining influence area; according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent ground stress, and the functional relationship between the first boundary stress of the broken zone on the softened zone under the first equivalent ground stress and the first support strength required for the roadway space and the radius of the broken zone, determining a first surrounding rock - support mutual feedback equilibrium curve under the first equivalent ground stress; determining a first support balance point of the first surrounding rock - support mutual feedback equilibrium curve; and according to the first support balance point and the stress of the bolt support of the roadway, determining the support strength of the hydraulic support to be selected for the surrounding rock.

[0005] Preferably, determining the first surrounding rock - support mutual feedback equilibrium curve under the first equivalent ground stress includes: determining the first boundary stress corresponding to the first equivalent ground stress according to the system equation of the roadway; and according to the first boundary stress, the functional relationship between the first boundary stress and the first support strength and the radius of the broken zone, and the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, determining the first surrounding rock - support mutual feedback equilibrium curve.

[0006] Preferably, the determination method further includes: according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the second equivalent ground stress of the roadway in the non-mining influence area, and the second boundary stress of the broken zone on the softened zone under the second equivalent ground stress and the functional relationship between the second support strength required for the roadway space and the radius of the broken zone, determining the second surrounding rock-support interaction balance curve under the second equivalent ground stress.

[0007] Preferably, determining the second surrounding rock-support interaction balance curve under the second equivalent ground stress includes: according to the system equation of the roadway, determining the second boundary stress system corresponding to the second equivalent ground stress; and according to the second boundary stress, the functional relationship between the second boundary stress and the second support strength required for the roadway space and the radius of the broken zone, and the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, determining the second surrounding rock-support interaction balance curve.

[0008] Preferably, determining the second surrounding rock-support interaction balance curve under the second equivalent ground stress includes: according to the system equation of the roadway, determining the second boundary stress corresponding to the second equivalent ground stress; and according to the second boundary stress, the functional relationship between the second boundary stress and the second support strength required for the roadway space and the radius of the broken zone, and the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, determining the second surrounding rock-support interaction balance curve.

[0009] Preferably, determining the first support balance point of the first surrounding rock-support interaction balance curve includes: in the case where there is no extreme point on the first surrounding rock-support interaction balance curve, determining the first support balance point according to the first surrounding rock-support interaction balance curve by using the surrounding rock separation control condition; or in the case where there is an extreme point on the first surrounding rock-support interaction balance curve, determining the extreme point of the first surrounding rock-support interaction balance curve as the first support balance point.

[0010] Preferably, the determination method further includes: determining the second support balance point of the second surrounding rock-support interaction balance curve. Correspondingly, determining the second support balance point of the second surrounding rock-support interaction balance curve includes: according to the ordinate of the first support balance point and the second surrounding rock-support interaction balance curve, determining the second support balance point, where the ordinate of the first support balance point is equal to the ordinate of the second support balance point.

[0011] Preferably, the surrounding rock separation control condition includes: the displacement of the surrounding rock of the roadway is less than or equal to a preset ratio of the equivalent radius of the roadway space.

[0012] Preferably, the determination method further includes: determining a second equivalent in-situ stress of the roadway in the non-mining-influenced area, where determining the second equivalent in-situ stress of the roadway in the non-mining-influenced area includes: according to the initial in-situ stress P0 and the uniaxial compressive strength σ of the coal and rock c and the following formula, determining the peak mining-induced stress P in the surrounding rock of the roadway in the non-mining-influenced area m ; and according to the peak mining-induced stress P m , the surrounding rock pressure relief efficiency coefficient W drill , the uniaxial compressive strength σ of the coal and rock c and the following formula, determining the second equivalent in-situ stress P2,

[0013] Preferably, determining the first equivalent in-situ stress of the roadway in the mining-influenced area includes: according to the initial in-situ stress P0 and the uniaxial compressive strength σ of the coal and rock c and the following formula, determining the peak mining-induced stress P in the surrounding rock of the roadway in the non-mining-influenced area m ; and according to the peak mining-induced stress P m , the pressure relief efficiency coefficient W of the roadway surrounding rock drill , the mining-induced stress concentration coefficient λ of the roadway in the mining-influenced area m , the uniaxial compressive strength σ of the coal and rock c and the following formula, determining the first equivalent in-situ stress P1,

[0014] Through the above technical solutions, the present invention creatively determines the surrounding rock-support interaction equilibrium curve under the first equivalent in-situ stress according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent in-situ stress, and the functional relationship between the first boundary stress of the broken zone on the softened zone and the required first support strength of the roadway space and the radius of the broken zone; determines the support balance point of the surrounding rock-support interaction equilibrium curve; and determines the support strength of the hydraulic support to be selected for the surrounding rock according to the support balance point and the stress of the bolt support of the roadway. The present invention considers the loading effect of the mining of the working face on the advanced roadway, can quantitatively determine the deformation coordination response and interaction equilibrium relationship between the "surrounding rock and support" of the rock burst roadway. Thus, the support strength of the hydraulic support to be selected for the surrounding rock can be accurately determined, and then the parametric selection of the rock burst prevention hydraulic support for the roadway can be realized based on the support strength.

[0015] The second aspect of the present invention also provides a method for selecting a hydraulic support. The selection method includes: determining the first support balance point, the second support balance point, and the support strength of the hydraulic support to be selected for the surrounding rock according to the above-mentioned method for determining the support strength; determining the minimum telescopic amount required for the movable column in the upright column of the hydraulic support according to the first support balance point and the second support balance point; and determining the hydraulic support matching the roadway according to the support strength of the hydraulic support to the surrounding rock and the minimum telescopic amount required for the movable column in the upright column.

[0016] Preferably, determining the hydraulic support matching the roadway includes: determining the static load working load and the energy absorption and yielding resistance required for impact prevention of the hydraulic support according to the support strength of the hydraulic support to the surrounding rock; and selecting the model of the hydraulic support according to the static load working load and the energy absorption and yielding resistance required for impact prevention of the hydraulic support and the minimum telescopic amount required for the movable column in the upright column.

[0017] Preferably, the selection method further includes: determining the extension amount of the movable column in the upright column according to the model of the selected hydraulic support and the height of the roadway; determining the stiffness of the selected hydraulic support according to the extension amount of the movable column in the upright column; and determining the initial support timing according to the initial support force, the working resistance of the selected hydraulic support, the stiffness, and the second support balance point.

[0018] Through the above technical solutions, the present invention creatively determines the first support balance point, the second support balance point, and the support strength of the hydraulic support to be selected for the surrounding rock according to the above-mentioned method for determining the support strength; determines the minimum telescopic amount required for the movable column in the upright column of the hydraulic support according to the first support balance point and the second support balance point; and then determines the hydraulic support matching the roadway according to the support strength of the hydraulic support to the surrounding rock and the minimum telescopic amount required for the movable column in the upright column. The present invention can achieve the precise selection of the impact prevention hydraulic support for the roadway based on the quantitative support strength required by the surrounding rock.

[0019] The third aspect of the present invention also provides a system for determining the support strength. The determining system includes: a stress determining device for determining the first equivalent in-situ stress of the roadway in the mining influence area; an equilibrium curve determining device for determining the first surrounding rock-support interaction equilibrium curve under the first equivalent in-situ stress according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent in-situ stress, the first boundary stress of the broken zone on the softened zone under the first equivalent in-situ stress, and the functional relationship between the first support strength required for the roadway space and the radius of the broken zone; a balance point determining device for determining the first support balance point of the first surrounding rock-support interaction equilibrium curve; and a support strength determining device for determining the support strength of the hydraulic support to be selected for the surrounding rock according to the first support balance point and the stress of the bolt support of the roadway.

[0020] Preferably, the balance point determining device for determining the first support balance point of the first surrounding rock-support interaction equilibrium curve includes: in the case where there is no extreme point on the first surrounding rock-support interaction equilibrium curve, determining the first support balance point according to the first surrounding rock-support interaction equilibrium curve by using the surrounding rock separation control condition; or in the case where there is an extreme point on the first surrounding rock-support interaction equilibrium curve, determining the extreme point of the first surrounding rock-support interaction equilibrium curve as the first support balance point.

[0021] Preferably, the balance point determining device is further configured to determine the second support balance point of the second surrounding rock-support interaction equilibrium curve. Correspondingly, the determination of the second support balance point of the second surrounding rock-support interaction equilibrium curve includes: in the case where there is no extreme point on the first surrounding rock-support interaction equilibrium curve, determining the second support balance point according to the ordinate of the first support balance point and the second surrounding rock-support interaction equilibrium curve; or in the case where there is an extreme point on the first surrounding rock-support interaction equilibrium curve, determining the second support balance point according to the ordinate of the first support balance point and the second surrounding rock-support interaction equilibrium curve, where the ordinate of the first support balance point is equal to the ordinate of the second support balance point.

[0022] The system for determining the support strength has the same advantages as the above-mentioned method for determining the support strength over the prior art, and will not be elaborated here.

[0023] The fourth aspect of the present invention further provides a selection system for hydraulic supports. The selection system includes: a determination system for the support strength as described above, which is used to determine the first support balance point, the second support balance point, and the support strength of the hydraulic support to be selected for the surrounding rock; a telescopic amount determination device, which is used to determine the minimum telescopic amount required for the movable column in the upright column of the hydraulic support according to the first support balance point and the second support balance point; and a hydraulic support determination device, which is used to determine the hydraulic support matching the roadway according to the support strength of the hydraulic support for the surrounding rock and the minimum telescopic amount required for the movable column in the upright column.

[0024] The advantages of the selection system for hydraulic supports and the above-mentioned selection method for hydraulic supports over the prior art are the same, and will not be elaborated here.

[0025] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification. Together with the following specific implementation, they are used to explain the embodiments of the present invention, but do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0027] Figure 1 is a schematic diagram of the energy transfer process of roadway rockburst under large-energy mine seismic disturbances;

[0028] Figure 2 is a flowchart of the method for determining the support strength provided by an embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of the working face and the range of its advanced stress concentration area;

[0030] Figure 4 is a schematic diagram of the peak mining-induced stress and the distribution of its original rock stress in the surrounding rock;

[0031] Figure 5 is a flowchart of the method for determining the first surrounding rock-support interaction balance curve under the first equivalent in-situ stress provided by an embodiment of the present invention;

[0032] Figure 6 is the type I curve of the "surrounding rock-support" interaction balance characteristic of the roadway provided by an embodiment of the present invention;

[0033] Figure 7 is the type II curve of the "surrounding rock-support" interaction balance characteristic of the advanced roadway provided by an embodiment of the present invention;

[0034] Figure 8 is a flowchart of the method for determining the remaining impact energy provided by an embodiment of the present invention;

[0035] Figure 9 is a flowchart of the selection method provided by an embodiment of the present invention; and

[0036] Figure 10 is the "surrounding rock - support" mutual feedback equilibrium characteristic curve of the roadway under specific in - situ stress provided by an embodiment of the present invention. Specific Embodiments

[0037] The following will detail the specific embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0038] The overall idea of the present invention is as follows: establish a mechanical analysis model for the occurrence of roadway rockburst, deduce and draw the mutual feedback equilibrium equation and characteristic curve of the "surrounding rock - support" of the roadway under in - situ stress; accordingly, determine whether there is an extreme point of dynamic instability in the roadway. If so, further determine parameters such as the magnitude of the critical support stress, the corresponding critical surrounding rock displacement, and the critical softening radius of the surrounding rock; calculate and determine the maximum energy release after the occurrence of roadway rockburst; respectively guide the selection of anti - burst hydraulic supports in accordance with the design principle of anti - burst support strength and the principle of energy conservation.

[0039] The roadway includes the surrounding rock and the roadway space formed by the surrounding rock (equivalent radius is ρ0), as Figure 1 shown. Among them, the surrounding rock of the roadway includes an elastic zone, a softening zone (radius is ρ p ) and a broken zone (radius is ρ d ), as Figure 1 shown. Based on the disturbance - response instability theory of rockburst occurrence, for a given coal - rock mass deformation system (roadway), under the action of the second equivalent in - situ stress P2 (or the first equivalent in - situ stress P1), the radius of the plastically softened zone (hereinafter simply referred to as the softening zone) is ρ P2 (or ρ P1 ), as Figure 4 shown.

[0040] The following will take two embodiments as examples for illustration, but are not limited to the following two embodiments. First, introduce the basic situations of the two embodiments, and then, by way of comparison, specifically introduce the processes of determining the support strength, the remaining impact energy, and the selection of hydraulic supports in the two embodiments.

[0041] Embodiment 1:

[0042] Under the action of the working face coal mining (P1 = 24.76 MPa), there is no dynamic instability point in the near - field surrounding rock of the roadway (the impact disaster - causing energy is only the energy of the far - field disturbance seismic source point).

[0043] In a certain mine, the coal seam is a nearly horizontal coal seam. The advanced roadway of the working face for the anti-bumping support design has a rectangular cross-section, with a height of 3.2 m and a cross-sectional width (i.e., the roadway width) of 4.4 m. The equivalent circular radius of the circumscribed circle of the rectangular roadway (i.e., the equivalent radius of the roadway space) is 2.7 m (which can be determined from the following text). The number of anchor cables in one row is 5, and the number of anchor bolts in one row is 9. The active support for this roadway is anchor mesh and cable support, which is to enhance the anti-bumping and impact resistance capabilities of the roadway.

[0044] The equivalent radius ρ0 of the roadway space can be determined according to the main rock mechanics parameters of the surrounding rock of the roadway (for example, the radius of the circumscribed circle of a rectangular roadway, ρ0 = 2.70 m); the rock mechanics parameters may include the uniaxial compressive strength σ c = 11.60 MPa, elastic modulus E = 2780 MPa, impact proneness index K of coal and rock = λ1 / E = 1.10, residual modulus of degradation λ2 = 14 MPa, residual strength coefficient ξ = 0.22, Poisson's ratio υ = 0.25; where λ1 is the modulus of degradation of softened coal and rock (MPa). The main parameters of the roadway and its surrounding rock can be seen in Table 1 in detail.

[0045] Table 1 Main physical and mechanical parameters of the roadway and its surrounding rock

[0046] Serial number Name of main control parameter Symbol Unit A certain mine in Shandong 1 Impact proneness index of coal and rock K — 1.10 2 Uniaxial compressive strength of coal and rock <![CDATA[σ c > MPa 11.60 3 Elastic modulus of coal and rock E Gpa 2.78 4 Internal friction angle Φ ° 30 5 Residual descending modulus <![CDATA[λ2]]> MPa 14 6 Residual strength coefficient ξ — 0.22 7 Poisson's ratio υ — 0.25 8 Height of roadway space H m 3.2 9 Width of roadway space B m 4.4 10 Equivalent radius of roadway space <![CDATA[ρ0]]> m 2.70 11 Original rock in-situ stress <![CDATA[P0]]> MPa 14.00 12 Mining-induced stress concentration coefficient of roadway in mining influence area <![CDATA[λ m > — 1.3138 13 Surrounding rock pressure relief efficiency coefficient <![CDATA[W drill > — 1 14 Equivalent in-situ stress of roadway in non-mining influence area <![CDATA[P2]]> MPa 14 15 Equivalent in-situ stress of roadway in mining influence area <![CDATA[P1]]> MPa 24.76

[0047] Example 2:

[0048] During the coal face mining, under the action of mining-induced stress (P1 = 47.62 MPa), dynamic instability points appear in the near-field surrounding rock of the roadway (the impact disaster-causing energy of the roadway surrounding rock includes the energy of the far-field disturbance seismic source point and the energy of the near-field surrounding rock dynamic instability).

[0049] The roadway cross-section of the 513 working face in a certain mine is nearly circular. The span of the coal seam mining roadway space (i.e., the width of the roadway space) is 5.2 m, and the height is 3.8 m.

[0050] (1) Original support form of the 513 outer section working face.

[0051] The support form for the two crossheadings of the 513 outer section working face is combined support of anchor mesh (cable) and shed; three-section U-shaped steel sheds are used, with 2 lap joints for each U-shaped steel shed, and 4 pairs of clips are used for each lap joint; and a bottom arc is added for sealing, with 4 lap joints for the bottom arc of each U-shaped steel shed, and 4 pairs of clips are used for each lap joint; the shed spacing for the coal roadway and semi-coal rock roadway is 500 mm; the specifications of the two-side anchor bolts: φ22×2400 mm, spacing in rows 800×1000 mm, and the number of anchor bolts is 8; the specifications of the roof anchor cables: φ21.6×8200 mm, spacing in rows 800×1000 mm, and the number of anchor cables is 6.

[0052] (2) Reinforcement support of constant-resistance anchor cables for the two crossheadings of the 513 outer section working face.

[0053] Before mining, high-pre-tension constant-resistance large-deformation anchor cables are used to reinforce the 300-meter range ahead of the transportation and return air roadways of the 513 outer-section working face. At the same time, grouting anchor cables are used to improve the overall self-bearing capacity of the surrounding rock, enabling the surrounding rock to adapt to the large deformation of the roadway, thereby enhancing its impact resistance. During the mining process, it is continuously advanced forward, and the distance of enhanced support is ensured to be no less than 300 meters. Among them: the transportation roadway starts construction from the open-off cut and stops at 20 meters outward from the intersection of the transportation roadway and the material roadway; the return air roadway starts construction from the open-off cut and stops at 20 meters outward from the intersection of the return air roadway and the material roadway. At the same time, during the mining process, energy-absorbing impact-resistant supports are used to strengthen the support for 200 meters ahead of the two roadways.

[0054] According to the main rock mechanical parameters of the surrounding rock of the mining roadway in the 513 working face, the equivalent radius ρ0 of the roadway space can be determined to be 2.59 m; the physical and mechanical parameters of the rock can include the uniaxial compressive strength σ c = 12.82 MPa, elastic modulus E = 2940 MPa, impact proneness index K of coal and rock = 1.86, residual modulus of reduction λ2 = 15, residual strength coefficient ξ = 0.24, and Poisson's ratio υ = 0.25. Assuming that the pressure relief of the roadway surrounding rock only changes the magnitude of the mining-induced stress distribution and ignoring the coupling effect between multiple impact prevention processes, the main parameters of the roadway and its surrounding rock to be supported by the impact-resistant support in the 513 working face are shown in Table 2.

[0055] Table 2 Main parameters of the mining roadway and its surrounding rock in the 513 working face of a certain mine

[0056] Serial number Name of main control parameter Symbol Unit Statistical value of parameter 1 Impact energy index of coal and rock K — 1.86 2 Uniaxial compressive strength of coal and rock <![CDATA[σ c > MPa 12.82 3 Elastic modulus of coal and rock E Mpa 2940 4 Internal friction angle Φ ° 30 5 Residual descending modulus <![CDATA[λ2]]> MPa 15 6 Residual strength coefficient ξ — 0.24 7 Poisson's ratio υ — 0.25 8 Roadway radius <![CDATA[ρ0]]> m 2.59 9 Original rock in-situ stress <![CDATA[P0]]> MPa 42.27 10 Mining-induced stress concentration coefficient of roadway in mining influence area <![CDATA[λ m > — 1.85 11 Surrounding rock pressure relief efficiency coefficient <![CDATA[W drill > — 0.6057 12 Equivalent in-situ stress of roadway in non-mining influence area <![CDATA[P2]]> MPa 24.76 13 Equivalent in-situ stress of roadway in mining influence area <![CDATA[P1]]> MPa 47.62

[0057] Figure 2 It is a flowchart of the method for determining the support strength provided by an embodiment of the present invention. As Figure 2 shown, the determination method may include the following steps S201 - S204.

[0058] Step S201, determine the first equivalent in-situ stress of the roadway in the mining influence area.

[0059] Among them, the roadway in the non-mining influence area refers to the roadway without mining influence, and the roadway in the mining influence area refers to the roadway under mining influence. The roadway in the non-mining influence area and the roadway in the mining influence area refer to the same roadway. The first equivalent in-situ stress P1 can be determined by the following method (Example 1: As Figure 4 or 6 shown, P1 = 24.76 MPa; Example 2: As Figure 7 shown, P1 = 47.62 MPa).

[0060] At the same time, the determination method further includes: determining the second equivalent in-situ stress of the roadway in the non-mining influence area.

[0061] Specifically, the determination of the first equivalent in-situ stress of the roadway in the mining-influenced area and the second equivalent in-situ stress of the roadway in the non-mining-influenced area may include the following three steps.

[0062] First, according to the initial in-situ stress P0, the uniaxial compressive strength σ of the coal and rock c and the following formula (1-1), determine the peak mining-induced stress P in the surrounding rock of the roadway in the non-mining-influenced area m ,

[0063]

[0064] Then, according to the peak mining-induced stress P m , the surrounding rock pressure relief efficiency coefficient W drill , the uniaxial compressive strength σ of the coal and rock c and the following formula (1-2), determine the second equivalent in-situ stress (i.e., the equivalent in-situ stress of the roadway in the non-mining-influenced area) P2,

[0065]

[0066] Finally, according to the peak mining-induced stress P m , the surrounding rock pressure relief efficiency coefficient W drill , the mining-induced stress concentration coefficient λ of the roadway in the mining-influenced area m , the uniaxial compressive strength σ of the coal and rock c and the following formula (1-3), determine the first equivalent in-situ stress (i.e., the equivalent in-situ stress P1 of the roadway in the mining-influenced area),

[0067]

[0068] Of course, the order of the above steps for determining the first equivalent in-situ stress and the second equivalent in-situ stress has no priority.

[0069] For Example 1: First, through P0 = 14 MPa, σ c = 11.60 MPa (as shown in Table 1) and the above formula (1-1), determine the peak mining-induced stress P in the surrounding rock of the roadway in the non-mining-influenced area m (as Figure 4 or 6 shows, P m = 23.9 MPa). Then, combining P m = 23.9 MPa, W drill = 1 and σ c = 11.60 MPa (as shown in Table 1), use the above formula (1-2) to determine the equivalent in-situ stress P2 of the roadway in the non-mining-influenced area (as Figure 4 or 6 shows, P2 = P0 = 14 MPa). Finally, combining P m = 23.9 MPa, W drill = 1, λm = 1.3138, σ c = 11.60 MPa and the above formula (1-3), determine the equivalent ground stress P1 of the roadway in the mining influence area (such as Figure 3 the roadway A shown) (as Figure 4 or 6 shows, P1 = 24.76 MPa).

[0070] For Example 2, first, the peak mining stress P in the surrounding rock of the roadway in the non-mining influence area can be determined by P0 = 42.27 MPa, σ c = 12.82 MPa (as shown in Table 1) and the above formula (1-1) m (such as Figure 4 or 6 shows, P m = 66.61 MPa). Then, combining P m = 66.61 MPa, W drill = 0.6057 and σ c = 12.82 MPa (as shown in Table 1), use the above formula (1-2) to determine the equivalent ground stress P2 of the roadway in the non-mining influence area (such as Figure 4 or 6 shows, P2 = 24.76 MPa). Finally, combining P m = 66.61 MPa, W drill = 0.6057, λ m = 1.85, σ c = 12.82 MPa and the above formula (1-3), determine the equivalent ground stress P1 of the roadway in the mining influence area (such as Figure 3 the roadway A shown) (as Figure 7 shows, P1 = 47.62 MPa).

[0071] Step S202: According to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent ground stress, and the functional relationship between the first boundary stress of the broken zone on the softened zone and the first support strength required for the roadway space and the radius of the broken zone, determine the first surrounding rock-support interaction balance curve under the first equivalent ground stress.

[0072] Regarding Step S202, the determination of the first surrounding rock-support interaction balance curve under the first equivalent ground stress may include the following Steps S501 - S502, as Figure 5 shown.

[0073] Step S501: According to the system equation of the roadway, determine the first boundary stress corresponding to the first equivalent ground stress.

[0074] The system equation of the roadway is as follows:

[0075]

[0076] Among them, m is an intermediate variable, is the internal friction angle of the surrounding rock; p d-p is the boundary stress (MPa) of the broken zone on the softened zone (which can be equal to the first boundary stress); P is the in-situ stress where the roadway is located (which can be equal to the first equivalent in-situ stress P1) (MPa); ρ d is the radius (m) of the broken zone, ρ p is the radius (m) of the softened zone, and k is a constant. The above formula (2) shows that with the change of the in-situ stress, the boundary stress of the broken zone on the softened zone changes. Specifically, the first equivalent in-situ stress P1 can be substituted into formula (2) to determine the corresponding first boundary stress.

[0077] Step S502, determine the first surrounding rock-support interaction balance curve according to the first boundary stress, the functional relationship between the first boundary stress and the first support strength and the radius of the broken zone, and the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone.

[0078] Among them, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone is:

[0079]

[0080] Among them, u a is the displacement (m) of the surrounding rock of the roadway; σ c is the uniaxial compressive strength; ρ d is the radius (m) of the broken zone of the surrounding rock; ρ0 is the equivalent radius (m) of the roadway space; λ1 is the softening modulus reduction of coal and rock (MPa); E is the elastic modulus of coal and rock (GPa); and ξ is the residual strength coefficient.

[0081] First, determine the functional relationship between the first boundary stress shown in the following formula (4) and the first support strength p sum required for the roadway space and the radius ρ d of the broken zone:

[0082]

[0083] Among them, ρ0 is the equivalent radius of the roadway space; p sum is the total support strength (MPa) of the support equipment in the roadway; q is an intermediate variable, is the internal friction angle of the surrounding rock in the broken zone. The above formula (4) shows that with the change of the boundary stress of the broken zone on the softened zone, the support strength required for the roadway space changes.

[0084] Then, by combining the first boundary stress and simultaneously solving equations (3)-(4), the first support strength p required for the roadway space with the equivalent radius ρ0 can be obtained. sum And the displacement u of the surrounding rock of the roadway a The functional relationship (not listed) between them (i.e., the first surrounding rock-support interaction balance curve, such as Figure 6 The curve corresponding to P1 shown). The curve corresponding to P1 indicates that under the combined action of the in-situ stress P1 and the first support strength p sum The broken zone with a radius of ρ d And the softened zone with a radius of ρ p Are in an equilibrium state.

[0085] While performing step S202, the second surrounding rock-support interaction balance curve under the second equivalent in-situ stress can also be determined. The determination method may further include: according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the second equivalent in-situ stress of the roadway in the non-mining influence area, and the functional relationship between the second boundary stress of the broken zone on the softened zone under the second equivalent in-situ stress and the second support strength required for the space formed by the roadway and the radius of the broken zone, determining the second surrounding rock-support interaction balance curve under the second equivalent in-situ stress.

[0086] Among them, determining the second surrounding rock-support interaction balance curve under the second equivalent in-situ stress may include: determining the second boundary stress corresponding to the second equivalent in-situ stress according to the system equation of the roadway; and determining the second surrounding rock-support interaction balance curve according to the second boundary stress, the functional relationship between the second boundary stress and the second support strength required for the space formed by the roadway and the radius of the broken zone, and the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone.

[0087] Specifically, the second boundary stress corresponding to the second equivalent in-situ stress shown in formula (2) can be determined. Wherein, P is the in-situ stress where the roadway is located (which can be equal to the second equivalent in-situ stress P2) (MPa). Then, determine the functional relationship between the second support strength p sum Required for the space formed by the roadway and the radius ρ d Of the broken zone. Finally, by combining the second boundary stress and simultaneously solving equations (3)-(4), the second support strength p required for the roadway space with the equivalent radius ρ0 can be obtained. sum And the displacement u of the surrounding rock of the roadway a The functional relationship (not listed) between them (i.e., the second surrounding rock-support interaction balance curve, such as Figure 6The curve corresponding to P2 as shown). The curve corresponding to P2 indicates that under the combined action of in-situ stress P2 and the second support strength p sum the crushed zone with a radius of ρ d is in equilibrium with the softened zone with a radius of ρ p .

[0088] That is to say, by simultaneously solving equations (2), (3) and (4), draw the "surrounding rock - support" mutual feedback equilibrium curve under the control of the second equivalent in-situ stress P2 and the first equivalent in-situ stress P1, and then determine whether there is an extreme point S0 (such as the one corresponding to Example 2) representing the impact instability of the surrounding rock of the roadway on the "surrounding rock - support" mutual feedback equilibrium curve under the control of the first equivalent in-situ stress P1 through the following step S203: If there is no extreme point S0 of dynamic instability, it is called the type I curve of the "surrounding rock - support" mutual feedback equilibrium characteristic of the roadway (such as the one corresponding to Example 1 Figure 7 as shown), for example, there is no extreme point in the working face roadway with a rectangular cross-section in Example 1, and the anti-bumping support design should consider the action of far-field disturbance seismic sources; otherwise, it is called the type II curve (such as the one corresponding to Example 2 Figure 6 as shown), for example, there is an extreme point in the 513 working face return airway of a certain mine in Example 2, and the anti-bumping support design should not only consider the impact of the near-field surrounding rock, but also fully consider the disturbance superposition effect of far-field mine seismic loads and energy. Figure 7

[0089] Step S203: Determine the first support balance point of the first surrounding rock - support mutual feedback equilibrium curve.

[0090] For step S203, determining the first support balance point of the first surrounding rock - support mutual feedback equilibrium curve may include any one of the following two situations.

[0091] Situation 1 (Example 1): In the case where there is no extreme point on the first surrounding rock - support mutual feedback equilibrium curve, determine the first support balance point according to the first surrounding rock - support mutual feedback equilibrium curve by using the surrounding rock separation control condition.

[0092] Among them, the surrounding rock separation control condition may include: the displacement of the surrounding rock of the roadway is less than or equal to a preset ratio of the equivalent radius of the roadway space. Specifically, the preset ratio can be any value between 0 - 6% (or any value between 0 - 9%).

[0093] Situation 2 (Example 2): In the case where there is an extreme point on the first surrounding rock - support mutual feedback equilibrium curve, determine the extreme point of the first surrounding rock - support mutual feedback equilibrium curve as the first support balance point.

[0094] Then, the second support balance point of the second surrounding rock - support mutual feedback equilibrium curve can be determined according to the first support balance point.​

[0095] The determination method may further include: determining a second support balance point of the second surrounding rock-support interaction balance curve. Accordingly, determining the second support balance point of the second surrounding rock-support interaction balance curve includes: determining the second support balance point according to the ordinate of the first support balance point and the second surrounding rock-support interaction balance curve. Wherein, the ordinate of the first support balance point is equal to the ordinate of the second support balance point.

[0096] The following respectively describes the specific processes for determining the first support balance point and the second support balance point for the above two cases.

[0097] For Case 1 (Embodiment 1): If there is no extreme point S0 (such as Figure 6 shown, Type I curve, that is, the roadway has no possibility of dynamic instability under high static load conditions) representing the impact instability of the roadway surrounding rock on the surrounding rock-support interaction balance curve under the control of the first equivalent ground stress P1, and the abscissa (displacement of the surrounding rock) of a point N1 on the first surrounding rock-support interaction balance curve meets the surrounding rock separation control condition (for example, the preset ratio is 4.18%), then determine this point N1 (u2 = 0.1129m, p sum = 0.43949MPa) as the first support balance point. Then, since the ordinate of the first support balance point is equal to the ordinate of the second support balance point, the second support balance point N0 (u1 = 0.03773m, p sum = 0.43949MPa) can be determined.

[0098] For Case 2 (Embodiment 2): If there is an extreme point S0 (such as Figure 7 shown, Type II curve, that is, the roadway has the possibility of dynamic instability under high static load conditions) representing the impact instability of the roadway surrounding rock on the surrounding rock-support interaction balance curve under the control of the first equivalent ground stress P1, then determine this extreme point S0 (0.57m, 0.68MPa) as the first support balance point. Then, since the ordinate of the first support balance point is equal to the ordinate of the second support balance point, the second support balance point N0 (0.08m, 0.68MPa) can be determined.

[0099] Step S204, determine the support strength of the hydraulic support to be selected for the surrounding rock according to the first support balance point and the stress of the bolt support of the roadway.

[0100] The support strength p sum can be determined according to the ordinate p bolt of the first support balance point, the stress p s-static of the bolt support of the roadway, and the following formula (5):

[0101] p s-static = (p sum - ω1p bolt ) / ω2, (5)

[0102] where ω1 and ω2 are the synergy coefficients of the anchoring support and the hydraulic support strength respectively. Further, the constant resistance support strength of the hydraulic support at the start of energy absorption and yielding can be determined as p s-dyn = mp s-static , where m is the gain coefficient of the support resistance of the energy absorber (the value range of m can be 1.0 - 1.5, and here it can be 1.3). Specifically, p s-dyn = 1.3 × 0.3619 = 0.47047 MPa.

[0103] Specifically, for the surrounding rock - support interaction balance curve (Type I curve) shown in Figure 6 , the support strength p s-static can be determined as 0.3619 MPa; while for the surrounding rock - support interaction balance curve (Type II curve) shown in Figure 7 , the support strength p s-static can be determined as 0.27 Mpa.

[0104] For the above - mentioned First Embodiment, although there is no dynamic instability point in the near - field surrounding rock of the roadway under the action of P1 = 24.76 MPa, when P1 increases to a certain value, an instability point will appear. The specific determination process is the same as that of the corresponding instability point in the Second Embodiment. For the Second Embodiment, under the action of P1 = 47.62 MPa, a dynamic instability point (i.e., the first instability point) appears in the near - field surrounding rock of the roadway. When the in - situ stress P1 increases to a certain value (such as P3), a new instability point (i.e., the second instability point) will appear, as shown in Figure 10 , and the specific determination process is the same as that of the corresponding instability point in the Second Embodiment.

[0105] In summary, the present invention creatively determines the first surrounding - rock - support interaction balance curve under the first equivalent in - situ stress according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent in - situ stress, and the functional relationship between the first boundary stress of the broken zone on the softened zone and the first support strength required for the roadway space and the radius of the broken zone; determines the first support balance point of the first surrounding - rock - support interaction balance curve; and determines the support strength of the to - be - selected hydraulic support for the surrounding rock according to the first support balance point and the stress of the anchoring support of the roadway. The present invention considers the loading effect of the coal face mining on the advanced roadway, can quantitatively determine the deformation coordination response and the interaction balance relationship between the "surrounding rock and support" of the rock - burst roadway. Thus, the support strength of the to - be - selected hydraulic support for the surrounding rock can be accurately determined, and then the parametric selection of the roadway impact - prevention hydraulic support can be realized based on the support strength.

[0106] Engineering practice has found that high-strength roadway support is beneficial to increasing the critical load for the initiation of rock bursts in roadways, making it difficult for rock bursts to occur or increasing the difficulty of their occurrence. Therefore, the roadway support design technology aimed at preventive treatment of rock bursts before the initiation of impacts naturally becomes an important aspect of coal mine rock burst prevention and control work.

[0107] An embodiment of the present invention also provides a method for selecting a hydraulic support. The selection method may include: determining the first support balance point, the second support balance point, and the support strength of the hydraulic support to be selected for the surrounding rock according to the method for determining the support strength; determining the minimum telescopic amount required for the movable column in the upright column of the hydraulic support according to the first support balance point and the second support balance point; and determining the hydraulic support matching the roadway according to the support strength of the hydraulic support for the surrounding rock and the minimum telescopic amount required for the movable column in the upright column.

[0108] Specifically, for Embodiment 1, according to the abscissa u1 of the second support balance point N0 and the abscissa u2 of the first support balance point N1, the minimum telescopic amount required for the movable column in the upright column can be determined as: L min = 2(u2 - u1) = 2×(0.1129m - 0.03773m) = 150.34mm. For Embodiment 2, according to the abscissa u a1 of the second support balance point N0 and the abscissa u a2 of the first support balance point S0, the minimum telescopic amount required for the movable column in the upright column can be determined as: L min = 2(u a2 - u a1 ) = 2×(0.57m - 0.08m) = 980mm.

[0109] Wherein, determining the hydraulic support matching the roadway may include: determining the static load working load and energy absorption and yielding resistance required for the hydraulic support to prevent rock bursts according to the support strength of the hydraulic support for the surrounding rock; and selecting the model of the hydraulic support according to the static load working load and energy absorption and yielding resistance required for the hydraulic support to prevent rock bursts and the minimum telescopic amount required for the movable column in the upright column.

[0110] Specifically, according to the support strength p s-static of the hydraulic support for the surrounding rock, the spacing l0 between any two adjacent hydraulic supports, the width B of the roadway, and F s-static = l0Bp s-static , determine the static load working load F s-static required for the hydraulic support to prevent rock bursts. Then, according to the static load working load F s-staticand F s-dny = mF s-static , the energy-absorbing yielding resistance F required for impact prevention of the hydraulic support can be determined s-dny .

[0111] For the two-column energy-absorbing impact-preventing hydraulic support with guide rod units, the spacing l0 between any two adjacent hydraulic supports is 2.5 m, the roadway width B is 4.4 m, and combined with the support strength p of the hydraulic support for the surrounding rock s-static = 0.3619 Mpa (for the roadway in Embodiment 1), calculate the static load working load F required for impact prevention of the support s-static = 3980.9 kN; and the energy-absorbing yielding resistance F required for impact prevention of the hydraulic support s-dny = mF s-static = 1.3×3980.9 kN = 5175.17 kN.

[0112] According to Table 3, the working resistance F of this hydraulic support w is 3300 kN and the energy-absorbing yielding resistance F n is 3750 kN. Since the static load working load (F s-static = 3980.9 kN) required for impact prevention of the support is greater than the working resistance (F w = 3300 kN) of this hydraulic support and the energy-absorbing yielding resistance (F s-dny = 5175.17 kN) required for impact prevention of the hydraulic support is greater than the energy-absorbing yielding resistance (F n = 3750 kN) of this hydraulic support, it can be concluded that the two-column energy-absorbing impact-preventing hydraulic support with guide rod units cannot meet the energy-absorbing impact prevention requirements of the current roadway.

[0113] Table 3 Parameter Table of Two-Column Energy-Absorbing Hydraulic Support with Guide Rod Units

[0114]

[0115] For the two-column energy-absorbing impact-preventing hydraulic support without guide rod units, the spacing l0 between any two adjacent hydraulic supports is 2.4 m, the roadway width B is 4.4 m, and combined with the support strength p of the hydraulic support for the surrounding rock s-static = 0.3619 MPa (for the roadway in Embodiment 1), calculate the static load working load F required for impact prevention of the support s-static = 3821.7 kN; and the energy-absorbing yielding resistance F required for impact prevention of the hydraulic support s-dny = mF s-static = 1.3×3821.7 kN = 4968.21 kN.

[0116] According to Table 4, the working resistance F of this hydraulic support wis 4000 kN and the energy-absorbing yielding resistance F n is 6000 kN. Since the static load working load (F s-static = 3821.7 kN) required for the support to prevent impact is less than the working resistance (F w = 4000 kN) of the hydraulic support and the energy-absorbing yielding resistance (F s-dny = 4968.21 kN) required for the hydraulic support to prevent impact is less than the energy-absorbing yielding resistance (F n = 6000 kN) of the hydraulic support, it can be concluded that the two-column unit type energy-absorbing impact-preventing hydraulic support can meet the energy-absorbing impact-preventing requirements of the current roadway.

[0117] It can also be known from Table 4 that the yielding stroke L sta of the movable support is 1900 mm. Since the minimum telescopic amount (L min = 150.34 mm) required for the movable support in the upright support is less than the yielding stroke (L sta = 1900 mm) of the movable support. The above criteria show that the two-column unit type energy-absorbing impact-preventing hydraulic support better meets the impact-preventing and energy-absorbing requirements of the current roadway in terms of the working resistance for impact yielding, the energy-absorbing yielding resistance, and the yielding stroke of the movable support.

[0118] Table 4 Parameters of the two-column unit type energy-absorbing hydraulic support without guide bar

[0119]

[0120] For the gantry type energy-absorbing impact-preventing hydraulic support, the distance l0 between any two adjacent hydraulic supports is 5 m, the roadway width B is 5.2 m, and combined with the support strength p s-static = 0.27 MPa (for the roadway in Embodiment 2), calculate the static load working load F s-static required for the support to prevent impact = 7020 kN. The working resistance F w-static of the gantry support is 6600 kN. Therefore, the static load working load (F s-static = 7020 kN) required for the support to prevent impact is greater than the working resistance (F w-static = 6600 kN) of the gantry support. The above criteria show that using the gantry type energy-absorbing support alone cannot meet the resistance requirements for impact prevention and support.

[0121] Furthermore, for the combination of the gantry type energy-absorbing impact-preventing hydraulic support and the crib type energy-absorbing support (for example, the impact prevention and resistance applicability of the support form with the crib type support interspersed between the gantry supports, which can be called the support combination), similarly, the static load working load F s-static required for the support to prevent impact can be calculated = 7020 kN. The working resistance F w-static1 of the gantry support is 6600 kN, and the working resistance F of the crib supportw-static2 is 4000 kN. Therefore, the static load working load (F s-static = 7020 kN) required for the support to prevent impact is less than the total working resistance (F w-static = 10600 kN) of the portal support and the crib support.

[0122] Therefore, the support design combined above meets the requirements of strength and impact prevention, and the impact prevention safety factor N s = F w-static / F s-static = 1.51.

[0123] For the combination of the portal impact - energy - absorbing hydraulic support and the crib impact - energy - absorbing support (i.e., the support combination), the yielding stroke L sta of the movable column is 1300 mm. To ensure the impact - energy - absorbing stroke, it is necessary to check whether the yielding stroke of the movable column of the support column under static pressure meets the large static - pressure deformation of the roadway. The criterion is as follows: Since the minimum telescopic amount (L min = 980 mm) required for the movable column in the column is less than the yielding stroke of the movable column (L sta = 1300 mm), as shown in Table 5. The above criterion shows that the combination of the portal impact - energy - absorbing hydraulic support and the crib impact - energy - absorbing support meets the current requirements of roadway impact prevention and energy absorption in terms of the working resistance of impact yielding, the energy - absorbing yielding resistance, and the yielding stroke of the movable column.

[0124] Table 5 Support design parameters and impact prevention safety factor for the mining roadway

[0125] Serial number Roadway support parameter Symbol Unit Calculated value 1 <![CDATA[Support stress at the instability point S0]]> <![CDATA[P scr > MPa 0.68 2 <![CDATA[Inward displacement of the roadway rib at the instability point S0]]> <![CDATA[u a2 > m 0.57 3 <![CDATA[Inbye displacement at the balance point N0]]> <![CDATA[u a1 > m 0.08 4 Support strength of bolt and O-shaped shed <![CDATA[P other > MPa 0.39 5 Support strength of support under static pressure <![CDATA[p s-static > MPa 0.27 6 Synergy coefficient of bolt-mesh-cable support <![CDATA[ω1]]> — 1.20 7 Synergy coefficient of hydraulic support <![CDATA[ω2]]> — 0.80 8 Minimum displacement of live column under static load yielding <![CDATA[L min > m 0.98 9 Critical broken zone radius of surrounding rock instability <![CDATA[ρ dcr > m 16.32 10 Critical softened zone radius of surrounding rock instability <![CDATA[ρ pcr > m 19.37 11 Energy consumption of surrounding rock softened and broken zone <![CDATA[E rock > J / m 4.11E+06 12 Energy absorption of single ordinary bolt <![CDATA[E ubolt > J 2.08E+04 13 Energy absorption of single ordinary cable <![CDATA[E ucable > J 1.28E+05 14 Energy absorption of single constant-resistance cable <![CDATA[E ubolt-con > J 5.25E+04 15 Energy absorption of bolt support per meter of roadway <![CDATA[E bolt-cable > J / m 4.71E+05 16 Most dangerous energy release magnitude <![CDATA[ML max > — 2.27 17 Most dangerous energy release <![CDATA[E max > J 7.7E+07 18 Kinetic energy of mine tremor of surrounding rock per meter of roadway <![CDATA[E c > J / m 9.44E+05 19 Energy release of surrounding rock in limit equilibrium zone <![CDATA[E cr > J / m 3.84E+06 20 Common support spacing <![CDATA[l0]]> m 5.00 21 Roadway support width B m 5.20 22 Minimum static working resistance of support <![CDATA[F s-static > kN 7020 23 Working resistance of candidate support <![CDATA[F w-static > kN 10600 24 Remaining impact energy of surrounding rock <![CDATA[E residual > J / m 2.03E+05 25 Energy absorption required for roadway support <![CDATA[E support > J 1.02E+06 26 Total energy absorption of candidate support <![CDATA[E imp > J 1.66E+06 27 Minimum yielding stroke of energy absorber <![CDATA[L str > m 0.74 28 Minimum shrinkage of live column <![CDATA[L min > m 0.98 29 Anti-bump safety factor <![CDATA[N s > — 1.51 30 Stop-bump safety factor <![CDATA[N e > — 1.63

[0126] The above - mentioned selection method further includes: determining the extension amount of the movable column in the column according to the model of the selected hydraulic support and the height of the roadway; determining the stiffness of the selected hydraulic support according to the extension amount of the movable column in the column; and determining the initial support timing according to the initial support force, working resistance of the selected hydraulic support, the stiffness, and the second support balance point.

[0127] Specifically, according to the model of the two - column unit - type impact - prevention support without guide rods, the support height (e.g., 2.6 m) is determined; subtracting the determined support height (e.g., 2.6 m) from the height H = 3.2 m of the roadway to be supported and designed to obtain the extension amount h = 0.6 m of the movable column in the column; further, according to the extension amount h = 0.6 m of the movable column, the support stiffness K support = 2.33×10 7 N / m can be determined; combined with the initial support force F initiate = 3090 kN (see Table 4 for details), the working resistance F w of the support, the stiffness value K support, the abscissa of the second support balance point (i.e., the displacement of the surrounding rock of the roadway corresponding to the balance point N0 between the surrounding rock of the roadway and the support under the action of the second equivalent in-situ stress P2) u1 and the following formula are used to determine the initial support timing (i.e., the approaching amount of the surrounding rock for the initial support) u0,

[0128]

[0129] Similarly, the average stiffness K of the support combination can be determined support equals 2.33×10 7 N / m; combined with the initial support force F of the support combination initiate = 8070 kN, the working resistance F of the support combination w-static and the stiffness value K of the support combination support , the abscissa of the second support balance point (i.e., the displacement of the surrounding rock of the roadway corresponding to the balance point N0 between the surrounding rock of the roadway and the support under the action of the second equivalent in-situ stress P2) u a1 and the following formula are used to determine the initial support timing, that is, the approaching amount of the surrounding rock for the initial support u a0 :

[0130]

[0131] An embodiment of the present invention further provides a system for determining the support strength. The determination system may include: a stress determination device for determining the first equivalent in-situ stress of the roadway in the mining influence area; an equilibrium curve determination device for determining the first surrounding rock - support mutual feedback equilibrium curve under the first equivalent in-situ stress according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent in-situ stress, and the functional relationship between the first boundary stress of the broken zone on the softened zone and the first support strength required for the roadway space and the radius of the broken zone; a balance point determination device for determining the first support balance point of the first surrounding rock - support mutual feedback equilibrium curve; and a support strength determination device for determining the support strength of the hydraulic support to be selected for the surrounding rock according to the first support balance point and the stress of the bolt support of the roadway.

[0132] Preferably, the balance point determination device for determining the first support balance point of the first surrounding rock - support mutual feedback equilibrium curve includes: in the case where there is no extreme point on the first surrounding rock - support mutual feedback equilibrium curve, determining the first support balance point according to the first surrounding rock - support mutual feedback equilibrium curve by using the surrounding rock separation control condition; or in the case where there is an extreme point on the first surrounding rock - support mutual feedback equilibrium curve, determining the extreme point of the first surrounding rock - support mutual feedback equilibrium curve as the first support balance point.

[0133] Preferably, the balance point determination device is further configured to determine a second support balance point of the second surrounding rock-support interaction balance curve. Correspondingly, determining the second support balance point of the second surrounding rock-support interaction balance curve includes: determining the second support balance point according to the ordinate of the first support balance point and the second surrounding rock-support interaction balance curve, where the ordinate of the first support balance point is equal to the ordinate of the second support balance point.

[0134] For the specific details and benefits of the support strength determination system provided by the present invention, reference may be made to the description of the support strength determination method above, which will not be elaborated here.

[0135] An embodiment of the present invention further provides a hydraulic support selection system. The selection system may include: a support strength determination system according to the above, configured to determine a first support balance point, a second support balance point, and the support strength of the hydraulic support to be selected for the surrounding rock; a telescopic amount determination device configured to determine the minimum telescopic amount required for the movable column in the hydraulic support according to the first support balance point and the second support balance point; and a hydraulic support determination device configured to determine the hydraulic support matching the roadway according to the support strength of the hydraulic support to the surrounding rock and the minimum telescopic amount required for the movable column in the column.

[0136] For the specific details and benefits of the hydraulic support selection system provided by the present invention, reference may be made to the description of the hydraulic support selection method above, which will not be elaborated here.

[0137] In summary, the present invention creatively determines the first support balance point, the second support balance point, and the support strength of the hydraulic support to be selected for the surrounding rock according to the support strength determination method described above; determines the minimum telescopic amount required for the movable column in the hydraulic support according to the first support balance point and the second support balance point; and then determines the hydraulic support matching the roadway according to the support strength of the hydraulic support to the surrounding rock and the minimum telescopic amount required for the movable column in the column. The present invention can achieve the precise selection of the roadway impact prevention hydraulic support based on the quantitative support strength required by the surrounding rock.

[0138] The existing energy absorption and impact prevention support design method directly regards the maximum value or dangerous value of the energy in the far-field microseismic events of the roadway as the essence of rock burst, and regards the attenuated vibration energy in the far field as the total energy released by rock burst. This will ignore the energy released by the instability of the surrounding rock in the near-field roadway ultimate equilibrium zone, resulting in a low estimation of the impact release energy.

[0139] Figure 8 It is a flowchart of the method for determining the remaining impact energy provided by an embodiment of the present invention. As Figure 8 shown, the determination method may include the following steps S801-S804.

[0140] Before performing step S801, the determination method may further include: determining the radius of the broken zone and the radius of the softened zone according to the system equation of the roadway, the first equivalent in-situ stress, the instability criterion of disturbance response, the damage variable of the coal and rock in the elastic zone of the surrounding rock, the damage variable of the coal and rock in the softened zone, and the damage variable of the coal and rock in the broken zone.

[0141] Specifically, according to the system equation of the roadway shown in equation (3), the first equivalent in-situ stress, the instability criterion of disturbance response shown in equation (6), the damage variable D0 of the coal and rock in the elastic zone listed from top to bottom shown in equation (7), the damage variable D1 of the coal and rock in the softened zone, and the damage variable D2 of the coal and rock in the broken zone, the radius ρ of the broken zone can be determined. d and the radius ρ of the softened zone P .

[0142]

[0143]

[0144] where ρ is the radius of the surrounding rock of the roadway (m); γ is an intermediate variable, γ = λ2 / E + (1 - ξ)λ2 / λ1 + ξ. It can be obtained through formula (6). For example, for Figure 6 the roadway corresponding to the type I curve shown, the radius ρ of the broken zone of the surrounding rock of the roadway under the action of the first equivalent in-situ stress P1 can be calculated. d = 7.9m, and the radius ρ of the softened zone p = 10.87m.

[0145] Alternatively, the above-mentioned respective radii (for example, the radius of the broken zone and the radius of the softened zone) can be determined according to the existing method.

[0146] Step S801: Determine the total energy consumption of the resistance zone of the surrounding rock according to the damage variable of the coal and rock in the softened zone and the damage variable of the coal and rock in the broken zone of the surrounding rock of the roadway, the equivalent radius of the roadway space, the radius of the broken zone, and the radius of the softened zone.

[0147] where the resistance zone includes the broken zone and the softened zone.

[0148] Specifically, according to the damage variable D1 of the coal and rock in the softened zone and the damage variable D2 of the coal and rock in the broken zone, the equivalent radius ρ0 of the roadway space, the radius ρ of the broken zone d and the radius ρ of the softened zone p and the following formula (8) (i.e., the minimum energy principle of coal and rock dynamic failure), determine the total energy consumption E of the resistance zone of the surrounding rock. rock :

[0149]

[0150] Among them, σ c is the uniaxial compressive strength of coal and rock; ξ is the residual strength coefficient; λ2 is the residual degradation modulus; λ1 is the softening degradation modulus of coal and rock.

[0151] For Figure 6 the roadway corresponding to the type I curve shown (Example 1), the total energy consumption E of the resistance zone of the surrounding rock can be determined rock to be 0.319856 MJ / m; for Figure 7 the roadway corresponding to the type II curve shown (Example 2), the total energy consumption E of the resistance zone of the surrounding rock can be determined rock = 4.11 MJ / m.

[0152] This step can quantitatively estimate the spatial range of the resistance zone of the surrounding rock during impact initiation, thereby accurately estimating the dissipated energy of the surrounding rock, and thus greatly improving the stability of the roadway.

[0153] Step S802, determine the kinetic energy generated by the impact of the resistance zone according to the most dangerous microseismic magnitude, the distance from the most dangerous microseismic focus to the failure point of the roadway, the radius of the softened zone, the equivalent radius of the roadway space, and the average density of the coal and rock in the resistance zone.

[0154] For step S802, the determination of the kinetic energy generated by the impact of the resistance zone may include: determining the impact movement speed of the coal and rock in the resistance zone during rockburst according to the most dangerous microseismic magnitude, the distance from the most dangerous microseismic focus to the failure point of the roadway, the radius of the softened zone, and the equivalent radius of the roadway space; determining the mass of the coal and rock in the resistance zone according to the radius of the softened zone, the equivalent radius of the roadway space, and the average density of the coal and rock in the resistance zone; and determining the kinetic energy generated by the impact of the resistance zone according to the impact movement speed and the mass of the coal and rock in the resistance zone.

[0155] Specifically, find the most dangerous historical impact event near the working face of the roadway to be designed (the maximum value of the equivalent impact event energy at the same epicentral distance), and record the most dangerous microseismic magnitude as ML max and the distance L0 from the most dangerous microseismic focus to the failure point of the roadway.

[0156] Then, according to the radius of the softened zone and the equivalent radius of the roadway space, determine the thickness of the resistance zone L1 = ρ p - ρ0. And calculate the peak vibration velocity v' of the surrounding rock mass at the outer boundary of the softened zone during rockburst according to the following formula (9),

[0157] lg[(L0 - L1)v'] = 3.95 + 0.57MLmax , (9)

[0158] In the case of obtaining the peak vibration velocity v′, the impact motion velocity v of the coal and rock in the resistance zone is v = 2v′.

[0159] Next, according to the radius ρ of the softened zone p , the equivalent radius ρ0 of the roadway space, the average density ρ of the coal and rock in the resistance zone c and determine the mass M of the coal and rock in the resistance zone of the surrounding rock per unit length of the roadway.

[0160] Finally, according to the impact motion velocity v, the mass M of the coal and rock in the resistance zone, and determine the kinetic energy E generated by the impact in the resistance zone c .

[0161] In Example 1, the energy E of the most dangerous induced impact seismic source in the far field monitored by the microseismic monitoring system max = 1.7×10 7 J. According to the conversion relationship between the microseismic magnitude and energy, the microseismic magnitude ML is obtained max ≈2.81. The distance from the most dangerous induced impact seismic source to the limit equilibrium zone of the roadway surrounding rock is L0 - L1 = 30.84 m. Using the relationship lg[(L0 - L1)v′] = 3.95 + 0.57ML max , when calculating that the induced impact energy reaches the limit equilibrium zone of the roadway, the peak vibration velocity v′ of the surrounding rock particles at the outer boundary of the coal and rock in the softened zone is approximately 1.15 m / s. Take the impact motion velocity in the range of the roadway softened zone as v = 2v′ = 2.3 m / s; take the density of the coal and rock as ρ c = 1.35×10 3 kg / m 3 , then the mass M of the coal and rock in the resistance zone per unit length of the roadway is: On this basis, the following can be obtained

[0162] In Example 2, the energy E of the most dangerous induced impact seismic source in the far field monitored by the microseismic monitoring system max = 7.7×10 7 J. According to the conversion relationship between the microseismic magnitude and energy, the microseismic magnitude ML is obtained max ≈2.27. The distance from the most dangerous induced impact seismic source to the limit equilibrium zone of the roadway surrounding rock is L0 - L1 = 32 m. Using the relationship lg[(L0 - L1)v′] = 3.95 + 0.57ML max, it is calculated that when the induced impact energy reaches the limit equilibrium zone of the roadway, the peak vibration velocity v' of the surrounding rock mass particles at the outer boundary of the softened coal and rock in the softened zone is approximately 0.55 m / s. The impact movement velocity in the softened zone range of the roadway is taken as v = 2v' = 1.10 m / s; the density ρ of the coal and rock is taken as c 1.35×10 3 kg / m 3 , then the mass of the thrown coal and rock in the resistance zone per unit length of the roadway On this basis, the energy of the far-field dynamic load causing the near-field coal and rock to be thrown per unit length of the roadway can be obtained as:

[0163] Step S803, determine the stable state of the roadway under the first equivalent in-situ stress.

[0164] Among them, the first equivalent in-situ stress is the equivalent in-situ stress received by the roadway A in the mining influence area in the roadway, such as Figure 4 or P1 shown in Figure 6.

[0165] For step S803, the determined stable state of the roadway under the first equivalent in-situ stress (i.e., whether there is a possibility of instability under high static load conditions) of the roadway may include: according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent in-situ stress, and the boundary stress of the broken zone on the softened zone under the first equivalent in-situ stress and the functional relationship between the required support strength of the roadway space and the radius of the broken zone, determine the surrounding rock-support mutual feedback equilibrium curve under the first equivalent in-situ stress; and determine the stable state of the roadway under the first equivalent in-situ stress in the following way: when there is no extreme point on the surrounding rock-support mutual feedback equilibrium curve, determine that there is no unstable state of the roadway under the first equivalent in-situ stress; or when there is an extreme point on the surrounding rock-support mutual feedback equilibrium curve, determine that there is an unstable state of the roadway under the first equivalent in-situ stress.

[0166] Among them, determining the surrounding rock-support mutual feedback equilibrium curve under the first equivalent in-situ stress includes: according to the system equation of the roadway, determine the functional relationship between the first equivalent in-situ stress and the boundary stress; and according to the functional relationship between the first equivalent in-situ stress and the boundary stress, the functional relationship between the boundary stress and the support strength and the radius of the broken zone, and the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, determine the surrounding rock-support mutual feedback equilibrium curve.

[0167] The above two processes can be seen in detail in the judgment of whether the extreme point S0 exists in the above text.

[0168] Step S804: Determine the remaining impact energy that the hydraulic support to be selected needs to absorb according to the stable state of the roadway under the first equivalent in-situ stress, the kinetic energy generated by the impact in the resistance zone, the total energy consumption in the resistance zone, and the energy consumption of the bolt support in the roadway.

[0169] According to the stable state of the roadway under high static load conditions, it is discussed in the following two cases.

[0170] Case 1 (Embodiment 1): When the roadway is in a non-instability state under the first equivalent in-situ stress, the determination of the remaining impact energy may include: subtracting the sum of the total energy consumption in the resistance zone and the energy consumption of the bolt support from the kinetic energy generated by the impact in the resistance zone to obtain the remaining impact energy.

[0171] First, introduce the process of estimating the energy consumption of the bolt support (for example, the energy consumption E bolt-cable ) per meter of the roadway.

[0172] For example, the bolt specification used in the roadway is a φ20×2500mm threaded steel bolt (calculated according to the yield strength σ s ≥380 MPa and the elongation δ g ≥15%). The energy absorption capacity of the bolt can be calculated based on the yield force and elongation: the energy absorbed by a single bolt E ubolt =πφ 2 σ s δl bolt / 4 = 31.32 kJ, where l bolt is the effective energy absorption length of the bolt (1750 mm).

[0173] The cable bolt specification used in the roadway is a steel strand with φ = 18.9 mm (calculated according to the yield strength σ s ≥1820 MPa and the elongation δ s ≥5%). The cable bolts supported on the roof and both sides have a length of 10.50 m. The energy absorption capacity of the cable bolt is calculated based on its yield force and elongation. The energy absorbed by a single cable bolt E ucable =πφ 2 σ s δl cable / 4 = 186.29 kJ. In the formula, l cable is the effective energy absorption length of the cable bolt.

[0174] On this basis, it can be estimated

[0175] In the formula, N is the number of bolts in a row of the roadway cross-section, M is the number of cable bolts in a row; S cable is the bolt row spacing, S cable is the cable bolt row spacing; ηbolt is the energy absorption efficiency of the bolt η cable is the energy absorption efficiency of the cable bolt

[0176] For the case where there is no possibility of instability in the roadway under the first equivalent in-situ stress, only the far-field disturbance energy needs to be considered (i.e., for a roadway where the surrounding rock of the roadway does not have an extreme point of dynamic instability under the first equivalent in-situ stress condition, only the energy impact of the far-field disturbance on the hydraulic support is regarded as the rockburst failure energy). After the far-field disturbance energy is consumed by the resistance zone and the anchor body, the remaining impact energy E that needs to be absorbed by the hydraulic support residual = E c - E bolt-cable - E rock = 0.2845 MJ / m.

[0177] Case 2 (Example 2): When the roadway is in an unstable state under the first equivalent in-situ stress, determining the remaining impact energy may include: determining the released energy of the elastic zone according to the first equivalent in-situ stress, the ordinate of the extreme point of the surrounding rock-support interaction balance curve, and the energy release rate of the elastic zone of the surrounding rock; and subtracting the sum of the total energy consumption of the resistance zone and the energy consumption of the anchor support from the sum of the released energy of the elastic zone and the kinetic energy generated by the impact of the resistance zone to obtain the remaining impact energy.

[0178] First, introduce the process of estimating the energy consumption of the anchor support (for example, the energy consumption E bolt-cable ) of the anchor support per meter of the roadway, and the energy absorption of the O-shaped shed support can be ignored.

[0179] Through testing and calculation, it can be obtained that the energy absorption E ubolt of a single traditional bolt and the energy absorption E ucable of a single traditional cable bolt are respectively: E ubolt = 2.08E+04 J; E ucable = 1.28E+05 J. Through testing and calculation, it can be obtained that the energy absorption E ucable-con of the reinforced constant-resistance cable bolt used in the roadway is 5.25E+04 J.

[0180] On this basis, the energy consumption E bolt-cable of the anchor support per unit length of the roadway can be calculated as:

[0181]

[0182] In the formula, N ubolt is the number of ordinary bolts in one row of the roadway section; M ucable and M ucable-con are respectively the number of ordinary cable bolts and constant-resistance cable bolts in one row of the roadway section; Sbolt is the row spacing of ordinary bolts; S cable and S cable-con are the row spacings of ordinary cable bolts and constant-resistance cable bolts respectively. Among them, based on the gradient characteristics of surrounding rock softening and fragmentation, the energy absorption efficiencies of bolts and cable bolts are determined: η bolt is the energy absorption efficiency of ordinary bolts, η cable is the energy absorption efficiency of traditional cable bolts, and η cable-con is the energy absorption efficiency of constant-resistance cable bolts,

[0183] Then, according to the first equivalent in-situ stress P1, the ordinate p of the extreme point S0 of the surrounding rock-support interaction balance curve scr and the energy release rate η of the elastic zone of the surrounding rock, the released energy E of the elastic zone is determined cr :

[0184]

[0185] Among them, p scr = p sum , which is the total support strength (MPa) of the support equipment in the roadway; q is an intermediate variable, is the internal friction angle of the surrounding rock in the broken zone; η can be any value between 0.1% and 1%. When η = 1%, E cr = 3.84×10 6 J / m.

[0186] For the case where the roadway has a possibility of instability under the first equivalent in-situ stress, it is necessary to consider the superimposed energy of the far-field disturbance energy and the elastic energy of the near-field roadway surrounding rock. After the superimposed energy is consumed by the resistance zone and the anchor body, the remaining impact energy E that needs to be absorbed by the hydraulic support residual = E c + E cr - E bolt-cable - E rock = 2.03×10 5 J / m. That is to say, the support parameters are determined based on the energy absorption and impact prevention principle based on energy conservation. Among them, the total energy absorbed by the energy absorption support is the impact energy of the far-field disturbance on the support and the elastic energy released by the limit equilibrium zone of the near-field roadway surrounding rock.

[0187] An embodiment of the present invention also provides a method for selecting a hydraulic support. The selection method may include: determining the remaining impact energy that the hydraulic support to be selected needs to absorb according to the method for determining the remaining impact energy; and determining the hydraulic support that matches the roadway according to the remaining impact energy that the hydraulic support needs to absorb.

[0188] Among them, determining the hydraulic support that matches the roadway may include: determining the energy absorption yielding stroke required for the energy absorber of the hydraulic support and the energy that needs to be absorbed by a single support in the hydraulic support according to the remaining impact energy that the hydraulic support needs to absorb; and selecting the model of the hydraulic support according to the energy absorption yielding stroke required for the energy absorber and the energy that needs to be absorbed by the single support.

[0189] Specifically, for a two-column unit type energy absorption and impact prevention hydraulic support without a guide rod, according to the distance l0 (l0 = 2.4 m) between any two adjacent hydraulic supports, the remaining impact energy E residual (E residual = 0.2845 MJ / m) that the hydraulic support needs to absorb, and the energy absorption yielding resistance (F n = 6000 kN) of the hydraulic support, determine the energy absorption yielding stroke L str = l0E residual / F n = 2.4 m * 0.2845 MJ / m / 6000 kN = 113.80 mm. According to the distance l0 (l0 = 2.4 m) between any two adjacent hydraulic supports and the remaining impact energy E residual (E residual = 0.2845 MJ / m), determine that the energy absorption required for the hydraulic support is E support = 0.2845 MJ / m * 2.4 m = 682.80 kJ.

[0190] Since the energy absorption yielding stroke L str (L str = 113.80 mm) of the hydraulic support is less than the impact yielding displacement L imp (L imp = 120 mm) of the support and the energy absorption required for a single support E support (E support = 682.80 kJ) is less than the yielding energy absorption E imp (E imp = 720 kJ) of a single support, the two-column unit type energy absorption and impact prevention hydraulic support without a guide rod can meet the current roadway's requirements for energy absorption and impact prevention in terms of impact yielding displacement, impact yielding energy absorption, etc.

[0191] Similarly, for the combination of a portal type energy absorption and impact prevention hydraulic support and a crib type energy absorption support (i.e., the support combination), according to the distance l0 (l0 = 5 m) between any two adjacent hydraulic supports, the remaining impact energy E residual (E residual = 2.03×10 5 J / m) that the hydraulic support needs to absorb, and the energy absorption yielding resistance (F w-static= 10600 kN), determine the energy-absorbing yielding stroke L of the hydraulic support str = l0E residual / 1.3F w-static = 73.66 mm. According to the spacing l0 (l0 = 5 m) between any two adjacent hydraulic supports and the remaining impact energy E residual (E residual = 2.03×10 5 J / m) that the hydraulic support needs to absorb, determine that the energy absorption required for the hydraulic support is E support = 2.03×10 5 J / m * 5 m = 1.02 MJ.

[0192] Since the energy-absorbing yielding stroke L str (L str = 73.66 mm) of the hydraulic support is less than the impact yielding displacement L imp (L imp = 120 mm) of the support and the energy absorption E support (E support = 1.02 MJ) required for a single support is less than the yielding energy absorption E imp (E imp = 1.66 MJ) of a single support, the support combination can meet the energy absorption and impact stopping requirements of the current roadway in terms of impact yielding displacement, impact yielding energy absorption, etc., and the impact stopping safety factor N e = E imp / E support = 1.63.

[0193] The selection method may further include: determining the extension amount of the movable column in the column according to the model of the selected hydraulic support and the height of the roadway; determining the stiffness of the selected hydraulic support according to the extension amount of the movable column in the column; and determining the initial support timing according to the initial support force, working resistance of the selected hydraulic support, the stiffness, and the support balance point of the surrounding rock-support interaction equilibrium curve under the second equivalent ground stress, where the second equivalent ground stress is the equivalent ground stress received by the roadway in the non-mining influence area.

[0194] The selection method may further include: determining the support balance points of the surrounding rock-support interaction balance curve under the first equivalent ground stress and the support balance points of the surrounding rock-support interaction balance curve under the second equivalent ground stress. Correspondingly, determining the support balance points of the surrounding rock-support interaction balance curve under the first equivalent ground stress includes: when there is no extreme point on the surrounding rock-support interaction balance curve under the first equivalent ground stress, using the surrounding rock separation control condition to determine the support balance points of the surrounding rock-support interaction balance curve under the first equivalent ground stress; or when there is an extreme point on the surrounding rock-support interaction balance curve under the first equivalent ground stress, determining the extreme point of the surrounding rock-support interaction balance curve under the first equivalent ground stress as the support balance points of the surrounding rock-support interaction balance curve under the first equivalent ground stress. Determining the support balance points of the surrounding rock-support interaction balance curve under the second equivalent ground stress includes: according to the ordinate of the support balance points of the surrounding rock-support interaction balance curve under the first equivalent ground stress and the surrounding rock-support interaction balance curve under the second equivalent ground stress, determining the support balance points of the surrounding rock-support interaction balance curve under the second equivalent ground stress, where the ordinate of the support balance points of the surrounding rock-support interaction balance curve under the first equivalent ground stress is equal to the ordinate of the support balance points of the surrounding rock-support interaction balance curve under the second equivalent ground stress.

[0195] For the specific process, please refer to the relevant description of determining the initial support timing in the above text.

[0196] An embodiment of the present invention further provides a system for determining the remaining impact energy. The determining system may include: an energy consumption determining device for determining the total energy consumption of the resistance zone of the surrounding rock according to the damage variables of the coal and rock in the softened zone and the damaged variables of the coal and rock in the broken zone of the surrounding rock of the roadway, the equivalent radius of the roadway space, the radius of the broken zone, and the radius of the softened zone, where the resistance zone includes the broken zone and the softened zone; a kinetic energy determining device for determining the kinetic energy generated by the impact of the resistance zone according to the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the damage point of the roadway, the radius of the softened zone, the equivalent radius of the roadway space, and the average density of the coal and rock in the resistance zone; a state determining device for determining the stable state of the roadway under the first equivalent ground stress, where the first equivalent ground stress is the equivalent ground stress received by the roadway in the mining influence area; and a remaining impact energy determining device for determining the remaining impact energy that the hydraulic support to be selected needs to absorb according to the stable state of the roadway under the first equivalent ground stress, the kinetic energy generated by the impact of the resistance zone, the total energy consumption of the resistance zone, and the energy consumption of the bolt support in the roadway.

[0197] For the specific details and benefits of the system for determining the remaining impact energy provided by the present invention, please refer to the description of the method for determining the remaining impact energy above, and will not be repeated here.

[0198] An embodiment of the present invention further provides a selection system for hydraulic supports. The selection system may include: a determination system for the remaining impact energy, configured to determine the remaining impact energy that needs to be absorbed by the hydraulic support to be selected; and a support determination device, configured to determine the hydraulic support that matches the roadway according to the remaining impact energy that the hydraulic support needs to absorb.

[0199] For the specific details and benefits of the selection system for hydraulic supports provided by the present invention, reference may be made to the description of the selection method for hydraulic supports above, which will not be elaborated here.

[0200] In summary, the present invention creatively determines the total energy consumption of the resistance zone of the surrounding rock according to the damage variables of the coal and rock in the softening zone and the damage variables of the coal and rock in the broken zone of the surrounding rock of the roadway, the equivalent radius of the roadway space, the radius of the broken zone, and the radius of the softening zone; determines the kinetic energy generated by the impact in the resistance zone according to the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the failure point of the roadway, the radius of the softening zone, the equivalent radius of the roadway space, and the average density of the coal and rock in the resistance zone; determines the stable state of the roadway under the first equivalent ground stress; and then determines the remaining impact energy that the hydraulic support to be selected needs to absorb according to the stable state of the roadway under the first equivalent ground stress, the kinetic energy generated by the impact in the resistance zone, the total energy consumption of the resistance zone, and the energy consumption of the bolt support in the roadway. By considering the superposition process of "the disturbance energy released in the far field of the roadway" and "the energy released in the near field of the roadway" when the roadway rock burst occurs, the present invention can quantitatively determine the remaining impact energy that the hydraulic support to be selected needs to absorb, and further realize the parametric selection of the anti-burst hydraulic support for the roadway based on the remaining impact energy.

[0201] The above separately introduces how to determine the relevant characteristic parameters of the hydraulic support (for example, the support strength of the hydraulic support for the surrounding rock, or the remaining impact energy that the hydraulic support needs to absorb, etc.) from two aspects of "prevention" (selecting the hydraulic support based on the support strength before the impact starts) and "treatment" (selecting the hydraulic support based on the remaining impact energy after the impact starts). In fact, it is also possible to combine the two aspects of "prevention" and "treatment", first determine the support strength of the hydraulic support for the surrounding rock and the remaining impact energy that the hydraulic support needs to absorb, and then determine the hydraulic support that matches the roadway according to the determined support strength and remaining impact energy.

[0202] An embodiment of the present invention further provides a selection method for hydraulic supports. As Figure 9 shown, the selection method may include the following steps S901 - S905.

[0203] Step S901, determine the first equivalent ground stress of the roadway in the mining influence area and the second equivalent ground stress of the roadway in the non - mining influence area.

[0204] Step S902: Determine the first surrounding rock - support interaction balance curve under the first equivalent in - situ stress and the second surrounding rock - support interaction balance curve under the second equivalent in - situ stress according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the second equivalent in - situ stress, the first equivalent in - situ stress, the first boundary stress of the broken zone on the softened zone under the first equivalent in - situ stress and the functional relationship between the first support strength required for the roadway space and the radius of the broken zone, and the second boundary stress of the broken zone on the softened zone under the second equivalent in - situ stress and the functional relationship between the second support strength required for the roadway space and the radius of the broken zone.

[0205] Step S903: Determine the support strength of the selected hydraulic support for the surrounding rock and the minimum telescopic amount required for the movable column in the hydraulic support column according to the first surrounding rock - support interaction balance curve, the second surrounding rock - support interaction balance curve, and the stress of the bolt - anchored support of the roadway.

[0206] Step S904: Determine the remaining impact energy that the hydraulic support needs to absorb according to the damage variables of the coal and rock in the softened zone of the surrounding rock, the damage variables of the coal and rock in the broken zone, the radius of the broken zone, the radius of the softened zone, the magnitude of the most dangerous micro - seismic event, the distance from the source of the most dangerous micro - seismic event to the failure point of the roadway, the equivalent radius of the roadway space, and the energy consumption of the bolt - anchored support.

[0207] Step S905: Determine the hydraulic support that matches the roadway according to the support strength of the hydraulic support for the surrounding rock, the remaining impact energy that the hydraulic support needs to absorb, and the minimum telescopic amount required for the movable column in the column.

[0208] Based on further considering the collaborative deformation and mutual feedback response of the "surrounding rock - support" system, the above - mentioned embodiment invents a design and selection method for an energy - absorbing hydraulic support from two aspects: strength design (impact prevention / "prevention") and energy design (impact stopping / "treatment"), to ensure the scientific operation of the impact - prevention support equipment with a reasonable safety factor.

[0209] For the specific process of determining the support strength, the remaining impact energy, and the minimum telescopic amount, reference can be made to the relevant descriptions in the above "prevention" or "treatment" solutions.

[0210] Among them, the determination of the hydraulic support matching the roadway may include: determining the static load working load and energy absorption and yielding resistance required for impact prevention of the hydraulic support according to the support strength of the hydraulic support for the surrounding rock; determining the energy absorption and yielding stroke required for the energy absorber of the hydraulic support and the energy required to be absorbed by a single support in the hydraulic support according to the remaining impact energy to be absorbed by the hydraulic support; and selecting the model of the hydraulic support according to the static load working load and energy absorption and yielding resistance required for impact prevention of the hydraulic support, the energy absorption and yielding stroke required for the energy absorber and the energy required to be absorbed by the single support, and the minimum telescopic amount required for the movable column in the upright column.

[0211] For the specific process of determining the static load working load, the energy absorption and yielding resistance, the energy absorption and yielding stroke, the energy required to be absorbed, and the minimum telescopic amount, reference can be made to the relevant descriptions in the above "prevention" or "treatment" solutions. Then, in combination with the above five determined parameters and corresponding criteria, the model of the hydraulic support can be comprehensively selected.

[0212] Thus, it can be determined that the two-column unit type energy absorption impact prevention hydraulic support (or a combination of portal and crib type supports) fully meets the requirements for the strength and energy of the energy absorption support in terms of the working resistance during impact yielding, the impact yielding displacement, the impact yielding energy absorption, the static load working load, and the yielding stroke of the movable column in the current roadway for impact prevention / impact stopping response.

[0213] After completing the applicability judgment of multiple or all supports, if multiple models meet the requirements, further optimization selection can be carried out from aspects such as the ground specific pressure and the anti-tipping of the support; if the designed energy absorption parameters determined by calculation cannot match the existing support model database, resulting in the inability to complete the support type selection, new parameter design of the support needs to be implemented.

[0214] After strengthening the coal seam area or local pressure relief work, re-evaluate the first equivalent in-situ stress P1 affected by the coal mining face, and perform other relevant steps to achieve cyclic calculation until all strength parameters and energy absorption parameters are reasonably determined or the working conditions to be designed are met by means of support customization. The exit criteria for cyclic type selection can be one or more of the following: the working resistance of the existing support is greater than or equal to the static load working load required for support impact prevention; the energy absorption and yielding resistance of the existing support is greater than or equal to the energy absorption and yielding resistance required for support impact prevention; the yielding stroke of the movable column of the existing support (i.e., the maximum extended length) is greater than the minimum telescopic amount required for the movable column in the upright column; the impact yielding displacement of the existing support is greater than or equal to the energy absorption and yielding displacement of the support; the impact energy absorption of the existing support > the required energy absorption of the support.

[0215] In summary, the present invention creatively determines the first equivalent in-situ stress of the roadway in the mining-influenced area and the second equivalent in-situ stress of the roadway in the non-mining-influenced area; according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the second equivalent in-situ stress, the first equivalent in-situ stress, the first boundary stress of the broken zone on the softened zone under the first equivalent in-situ stress and the functional relationship between the first support strength required for the roadway space and the radius of the broken zone, and the second boundary stress of the broken zone on the softened zone under the second equivalent in-situ stress and the functional relationship between the second support strength required for the roadway space and the radius of the broken zone, determine the first surrounding rock-support interaction balance curve under the first equivalent in-situ stress and the second surrounding rock-support interaction balance curve under the second equivalent in-situ stress; according to the first surrounding rock-support interaction balance curve, the second surrounding rock-support interaction balance curve and the stress of the bolt support of the roadway, determine the support strength of the hydraulic support to be selected for the surrounding rock and the minimum telescopic amount required for the movable column in the hydraulic support column; according to the damage variable of the coal and rock in the softened zone of the surrounding rock and the damage variable of the coal and rock in the broken zone, the radius of the broken zone, the radius of the softened zone, the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the failure point of the roadway, the equivalent radius of the roadway space and the energy consumption of the bolt support, determine the remaining impact energy required to be absorbed by the hydraulic support; and according to the support strength of the hydraulic support to the surrounding rock, the remaining impact energy required to be absorbed by the hydraulic support and the minimum telescopic amount required for the movable column in the column, determine the hydraulic support matching the roadway. Thus, on the one hand, the present invention considers the loading effect of the mining of the working face on the advanced roadway, and can quantitatively determine the deformation coordination response and the interaction balance relationship between the "surrounding rock and the support" of the rockburst roadway; on the other hand, it also considers the superposition process of the "energy released and disturbed in the far field of the roadway" and the "energy released in the near field of the roadway" when the rockburst of the roadway occurs, and can quantitatively determine the remaining impact energy required to be absorbed by the hydraulic support to be selected. Therefore, the support strength of the hydraulic support to be selected for the surrounding rock and the remaining impact energy can be accurately determined, and further, the parametric selection of the rockburst prevention hydraulic support can be realized at least based on the support strength and the remaining impact energy.

[0216] An embodiment of the present invention further provides a selection system for hydraulic supports. The selection system may include: a stress determination device configured to determine a first equivalent in-situ stress of a roadway in a mining-influenced area and a second equivalent in-situ stress of a roadway in a non-mining-influenced area; an equilibrium curve determination device configured to determine, according to a system equation of the roadway, a functional relationship between a displacement of surrounding rock of the roadway and a radius of a broken zone, the second equivalent in-situ stress, the first equivalent in-situ stress, a first boundary stress of the broken zone on a softened zone under the first equivalent in-situ stress and a functional relationship between a first support strength required for the roadway space and the radius of the broken zone, and a second boundary stress of the broken zone on the softened zone under the second equivalent in-situ stress and a functional relationship between a second support strength required for the roadway space and the radius of the broken zone, a first surrounding rock-support interaction equilibrium curve under the first equivalent in-situ stress and a second surrounding rock-support interaction equilibrium curve under the second equivalent in-situ stress; a telescopic amount determination device configured to determine, according to the first surrounding rock-support interaction equilibrium curve, the second surrounding rock-support interaction equilibrium curve, and a stress of the bolt support of the roadway, a support strength of the hydraulic support to be selected for the surrounding rock and a minimum telescopic amount required for a moving column in a column of the hydraulic support; a remaining impact energy determination device configured to determine, according to a damage variable of coal and rock in a softened zone of the surrounding rock, a damage variable of coal and rock in a broken zone, the radius of the broken zone, the radius of the softened zone, a magnitude of the most dangerous microseismic event, a distance from the source of the most dangerous microseismic event to a failure point of the roadway, an equivalent radius of the roadway space, and an energy consumption of the bolt support, a remaining impact energy that the hydraulic support needs to absorb; and a hydraulic support determination device configured to determine, according to the support strength of the hydraulic support for the surrounding rock, the remaining impact energy that the hydraulic support needs to absorb, and the minimum telescopic amount required for the moving column in the column, a hydraulic support that matches the roadway.

[0217] For specific details and benefits of the selection system for hydraulic supports provided by the present invention, reference may be made to the description of the selection method for hydraulic supports above, which will not be elaborated here.

[0218] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the selection method for hydraulic supports as described above is implemented.

[0219] It should be noted that steps executed by each device in the selection system or the determination system may be executed by a processor.

[0220] The beneficial effects of the above various embodiments of the present invention at least include the following three points:

[0221] First, a method for selecting an impact - resistant and energy - absorbing hydraulic support for roadway rockburst is provided. This method is based on the quantitative theoretical formulas for roadway rockburst occurrence and its critical occurrence conditions, clarifying the physical processes of static and dynamic stress and energy superposition of surrounding rocks in the near - field and far - field during roadway rockburst, laying a solid cognitive foundation for the physical process of rockburst for the selection of impact - resistant supports.

[0222] Second, by considering the combination of analytical calculation and engineering statistics, the quantitative estimation of "disturbance energy released in the far - field of the roadway" and "energy released in the near - field of the roadway" is realized, and the feasibility, applicability criteria and design methods for the design of energy - absorbing impact - resistant supports are given more comprehensively. This lays a scientific mathematical calculation method and basis for the selection of impact - resistant supports.

[0223] Third, fully considering the mutual feedback, balanced deformation and coordinated response relationship between "surrounding rock and support" in the rockburst roadway, it will effectively guide the parametric selection of support equipment based on stability, such as parameters like energy - absorbing resistance, yielding stroke, support stiffness, initial support force, etc.

[0224] The optional implementation manners of the embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above - mentioned implementation manners. Within the technical concept scope of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0225] In addition, it should be noted that, in the above - described specific implementation manners, the various specific technical features can be combined in any suitable way without contradiction. To avoid unnecessary repetition, the embodiments of the present invention do not separately describe various possible combination manners.

[0226] Those skilled in the art can understand that all or part of the steps of implementing the above - mentioned embodiment methods can be completed by instructing relevant hardware through a program. This program is stored in a storage medium, including several instructions for causing a single - chip microcomputer, a chip or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read - only memories (ROM, Read - Only Memory), random access memories (RAM, Random Access Memory), magnetic disks or optical discs that can store program codes.

[0227] In addition, any combination can be made between different implementation manners of the embodiments of the present invention as long as it does not violate the idea of the embodiments of the present invention, and it should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A method for determining the support strength, characterized in that, The determination method includes: Determining the first equivalent ground stress of the roadway in the mining influence area; According to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent ground stress, and the first boundary stress of the broken zone on the softened zone under the first equivalent ground stress and the functional relationship between the first support strength required for the roadway space and the radius of the broken zone, determining the first surrounding rock - support interaction balance curve under the first equivalent ground stress; Determining the first support balance point of the first surrounding rock - support interaction balance curve; and According to the first support balance point and the stress of the bolt support of the roadway, determining the support strength of the hydraulic support to be selected for the surrounding rock.

2. The determination method according to claim 1, characterized in that The determining the first support balance point of the first surrounding rock - support interaction balance curve includes: In the case where there is no extreme point on the first surrounding rock - support interaction balance curve, determining the first support balance point according to the first surrounding rock - support interaction balance curve by using the surrounding rock separation control condition; or In the case where there is an extreme point on the first surrounding rock - support interaction balance curve, determining the extreme point of the first surrounding rock - support interaction balance curve as the first support balance point.

3. The determination method according to claim 2, characterized in that, The surrounding rock separation control condition includes: the displacement of the surrounding rock of the roadway is less than or equal to a preset ratio of the equivalent radius of the roadway space.

4. The determination method according to claim 1, wherein The determining the first equivalent ground stress of the roadway in the mining influence area includes: According to the initial in-situ stress P0 and the uniaxial compressive strength σ of coal and rock c and the following formula, determine the peak mining-induced stress P in the surrounding rock of the roadway in the non-mining-influenced area m ; According to the peak mining-induced stress P m , the pressure relief efficiency coefficient W of the roadway surrounding rock drill , the mining-induced stress concentration coefficient λ of the roadway in the mining influence area m , the uniaxial compressive strength σ of the coal and rock c and the following formula, determine the first equivalent in-situ stress P1 5. A method for selecting a hydraulic support, characterized in that The selection method includes: According to the determination method of the support strength described in any one of claims 1 - 4, determining the first support balance point and the support strength of the hydraulic support to be selected for the surrounding rock; Determining the second equivalent ground stress of the roadway in the non - mining influence area; According to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the second equivalent ground stress of the roadway in the non - mining influence area, and the second boundary stress of the broken zone on the softened zone under the second equivalent ground stress and the functional relationship between the second support strength required for the roadway space and the radius of the broken zone, determining the second surrounding rock - support interaction balance curve under the second equivalent ground stress; Determining the second support balance point of the second surrounding rock - support interaction balance curve; According to the abscissa of the first support balance point and the abscissa of the second support balance point, determining the minimum telescopic amount required for the movable column in the upright column of the hydraulic support; and According to the support strength of the hydraulic support for the surrounding rock and the minimum telescopic amount required for the movable column in the upright column, determining the hydraulic support matching the roadway.

6. The selection method according to claim 5, wherein The determining the second support balance point of the second surrounding rock - support interaction balance curve includes: determining the second support balance point according to the ordinate of the first support balance point and the second surrounding rock - support interaction balance curve, wherein, the ordinate of the first support balance point is equal to the ordinate of the second support balance point.

7. The option selection method according to claim 5, characterized in that The determining the second equivalent ground stress of the roadway in the non - mining influence area includes: According to the in-situ stress P0 of the original rock and the uniaxial compressive strength σ of the coal rock c and the following formula, determine the peak mining-induced stress P in the surrounding rock of the roadway in the non-mining-influenced area m ; According to the peak mining-induced stress P m , the surrounding rock pressure relief efficiency coefficient W drill , the uniaxial compressive strength σ of the coal and rock c and the following formula, determine the second equivalent in-situ stress P2 8. The option selection method according to claim 5, wherein The determining the hydraulic support matching the roadway includes: Determine the static load working load and energy absorption yielding resistance required for impact prevention of the hydraulic support according to the support strength of the hydraulic support for the surrounding rock; and Select the model of the hydraulic support according to the static load working load and energy absorption yielding resistance required for impact prevention of the hydraulic support and the minimum telescopic amount required for the movable column in the upright post.

9. The option selection method according to claim 8, wherein The model selection method further includes: Determine the extension amount of the movable column in the upright post according to the model of the selected hydraulic support and the height of the roadway; Determine the stiffness of the selected hydraulic support according to the extension amount of the movable column in the upright post; and Determine the initial support timing according to the initial support force, working resistance of the selected hydraulic support, the stiffness and the second support balance point.

10. A system for determining the support strength, characterized in that, The determination system includes: A stress determination device for determining the first equivalent ground stress of the roadway in the mining influence area; An equilibrium curve determination device for determining the first surrounding rock - support mutual feedback equilibrium curve under the first equivalent ground stress according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the first equivalent ground stress, and the functional relationship between the first boundary stress of the broken zone on the softened zone and the required first support strength of the roadway and the radius of the broken zone; An equilibrium point determination device for determining the first support equilibrium point of the first surrounding rock - support mutual feedback equilibrium curve; and A support strength determination device for determining the support strength of the hydraulic support to be selected for the surrounding rock according to the first support equilibrium point and the stress of the bolt support of the roadway.

11. The determination system according to claim 10, wherein The equilibrium point determination device for determining the first support equilibrium point of the first surrounding rock - support mutual feedback equilibrium curve includes: In the case where there is no extreme point on the first surrounding rock - support mutual feedback equilibrium curve, determine the first support equilibrium point according to the first surrounding rock - support mutual feedback equilibrium curve by using the surrounding rock separation control condition; or In the case where there is an extreme point on the first surrounding rock - support mutual feedback equilibrium curve, determine the extreme point of the first surrounding rock - support mutual feedback equilibrium curve as the first support equilibrium point.

12. A selection system for a hydraulic support, characterized in that, The model selection system includes: The support strength determination system according to claim 10 or 11, for determining the first support equilibrium point and the support strength of the hydraulic support to be selected for the surrounding rock; A second support equilibrium point determination device for determining the second equivalent ground stress of the roadway in the non - mining influence area; according to the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the broken zone, the second equivalent ground stress of the roadway in the non - mining influence area, and the functional relationship between the second boundary stress of the broken zone on the softened zone and the required second support strength of the roadway space and the radius of the broken zone, determine the second surrounding rock - support mutual feedback equilibrium curve under the second equivalent ground stress, and determine the second support equilibrium point of the second surrounding rock - support mutual feedback equilibrium curve; A telescopic amount determination device for determining the minimum telescopic amount required for the movable column in the upright post of the hydraulic support according to the abscissa of the first support equilibrium point and the abscissa of the second support equilibrium point; and A hydraulic support determination device is used to determine the hydraulic support that matches the roadway according to the support strength of the hydraulic support for the surrounding rock and the minimum telescopic amount required for the movable column in the upright post.

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