Selection method of anti-rock burst support in rock burst tunnel based on residual rock burst energy

Abstract

The present invention relates to the field of tunnel support technology, and discloses a method for selecting an impact rock pressure tunnel anti-impact support based on residual impact energy. The method for determining the residual impact energy includes: determining the total energy consumption of the resistance zone of the surrounding rock; determining the kinetic energy generated by the impact of the resistance zone; determining the stable state of the tunnel under the first equivalent ground stress; and determining the residual impact energy that the hydraulic support to be selected needs to absorb based on the stable state of the tunnel 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 anchor support in the tunnel. The present invention can quantitatively determine the residual impact energy that the hydraulic support to be selected needs to absorb by considering the superposition process of "disturbance energy released in the far field of the tunnel" and "energy released in the near field of the tunnel" when rock pressure impact occurs in the tunnel, thereby realizing the parametric selection of the tunnel anti-impact hydraulic support.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel support, and in particular to a method for selecting an anti-impact support for an impact rock pressure tunnel based on residual impact energy. Background Art

[0002] Rock burst is one of the most serious dynamic hazards in coal mines and a world-class challenge faced by both the rock mechanics and mining communities today. Looking at the entire physical process of rock burst, although rock burst often occurs in milliseconds to seconds, it can still be divided into a pre-incubation phase before the impact initiation point and a destructive phase after the impact initiation point. Because dynamic hazards in deep coal mines often exhibit the characteristics of strong randomness of shock-induced impacts, a wide range of impact-induced disasters, and difficulty in predicting impact initiation, energy-absorbing support technology, which aims to prevent and control impacts after impact initiation, has naturally become the last safety barrier in coal mine rock burst prevention and control.

[0003] However, the existing tunnel support design methods and equipment selection methods cannot achieve quantitative analysis of the destruction stage of the rock burst tunnel after impact initiation, and cannot achieve accurate selection of anti-impact support equipment based on energy absorption capacity. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for selecting anti-impact supports for tunnel impact rock pressure based on residual impulse energy. By considering the superposition process of "disturbance energy released in the tunnel far field" and "energy released in the tunnel near field" when tunnel impact rock pressure occurs, the method can quantitatively determine the residual impulse energy that the hydraulic support to be selected needs to absorb, and then realize the parametric selection of tunnel anti-impact hydraulic supports based on the residual impulse energy.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a method for determining residual impulse energy, which includes: determining the total energy consumption of the resistance zone of the surrounding rock according to the damage variables of the coal rock in the softening zone and the damage variables of the coal rock in the crushing zone of the surrounding rock of the tunnel, the equivalent radius of the tunnel space, the radius of the crushing zone and the radius of the softening zone, wherein the resistance zone includes the crushing zone and the softening zone; 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 destruction point of the tunnel, the radius of the softening zone, the equivalent radius of the tunnel space and the average density of the coal rock in the resistance zone; determining the stable state of the tunnel under the first equivalent ground stress, wherein the first equivalent ground stress is the equivalent ground stress to which the tunnel in the mining influence zone is subjected; and determining the residual impulse energy required to be absorbed by the hydraulic support to be selected according to the stable state of the tunnel 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 anchor support in the tunnel.

[0006] Preferably, the determination of the stable state of the tunnel under the first equivalent in-situ stress includes: determining the surrounding rock-support mutual feedback equilibrium curve under the first equivalent in-situ stress according to the system equation of the tunnel, the functional relationship between the displacement of the surrounding rock of the tunnel and the radius of the crushing zone, the first equivalent in-situ stress and the functional relationship between the boundary stress of the crushing zone to the softening zone under the first equivalent in-situ stress and the support strength required for the tunnel space and the radius of the crushing zone; and determining the stable state of the tunnel under the first equivalent in-situ stress in the following manner: determining that the tunnel does not exist in an unstable state under the first equivalent in-situ stress when there is no extreme point in the surrounding rock-support mutual feedback equilibrium curve; or determining that the tunnel exists in an unstable state under the first equivalent in-situ stress when there is an extreme point in the surrounding rock-support mutual feedback equilibrium curve.

[0007] Preferably, when the tunnel is not in an unstable state under the first equivalent ground stress, determining the residual impulse energy includes: subtracting the sum of the total energy consumption of the resistance zone and the energy consumption of the anchor support from the kinetic energy generated by the impact of the resistance zone to obtain the residual impulse energy.

[0008] Preferably, when the tunnel is in an unstable state under the first equivalent ground stress, determining the residual impulse energy includes: determining the released energy of the elastic zone based on the first equivalent ground stress, the vertical coordinate of the extreme point of the surrounding rock-support mutual feed equilibrium 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 residual impulse energy.

[0009] Preferably, determining the surrounding rock-support mutual feedback balance curve under the first equivalent ground stress includes: determining the functional relationship between the first equivalent ground stress and the boundary stress according to the system equation of the tunnel; and determining the surrounding rock-support mutual feedback balance curve according to the functional relationship between the first equivalent ground stress and the boundary stress, the functional relationship between the boundary stress and the support strength and the crushing zone radius, and the functional relationship between the displacement of the surrounding rock of the tunnel and the crushing zone radius.

[0010] Preferably, determining the kinetic energy generated by the impact of the resistance zone includes: determining the impact movement speed of the coal rock in the resistance zone when the impact ground pressure occurs based on the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the radius of the softening zone and the equivalent radius of the tunnel space; determining the mass of the coal rock in the resistance zone based on the radius of the softening zone, the equivalent radius of the tunnel space and the average density of the coal rock in the resistance zone; and determining the kinetic energy generated by the impact of the resistance zone based on the impact movement speed and the mass of the coal rock in the resistance zone.

[0011] Preferably, the determination method also includes: determining the radius of the crushing zone and the radius of the softening zone based on the system equation of the tunnel, the first equivalent ground stress, the disturbance response instability criterion, the damage variables of the coal rock in the elastic zone of the surrounding rock, the damage variables of the coal rock in the softening zone, and the damage variables of the coal rock in the crushing zone.

[0012] Through the above technical scheme, the present invention creatively determines the total energy consumption of the resistance zone of the surrounding rock based on the damage variables of the coal rock in the softening zone and the damage variables of the coal rock in the crushing zone of the surrounding rock of the tunnel, the equivalent radius of the tunnel space, the radius of the crushing zone and the radius of the softening zone; determines the kinetic energy generated by the impact of the resistance zone based on the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the radius of the softening zone, the equivalent radius of the tunnel space and the average density of the coal rock in the resistance zone; determines the stable state of the tunnel under the first equivalent ground stress; and then determines the residual impact energy that the hydraulic support to be selected needs to absorb based on the stable state of the tunnel 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 anchoring support in the tunnel. By considering the superposition process of "disturbance energy released in the far field of the tunnel" and "energy released in the near field of the tunnel" when tunnel impact ground pressure occurs, the present invention can quantitatively determine the residual impact energy that the hydraulic support to be selected needs to absorb, and then realize the parametric selection of tunnel anti-impact hydraulic support based on the residual impact energy.

[0013] The second aspect of the present invention provides a method for selecting a hydraulic support, the selection method comprising: determining the residual impulse energy required to be absorbed by the hydraulic support to be selected according to the residual impulse energy determination method; and determining the hydraulic support that matches the tunnel according to the residual impulse energy required to be absorbed by the hydraulic support.

[0014] Preferably, determining the hydraulic support that matches the roadway includes: determining the required absorption and displacement stroke of 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 residual impact energy that the hydraulic support needs to absorb; and selecting the model of the hydraulic support according to the required absorption and displacement stroke of the energy absorber and the energy required to be absorbed by the single support.

[0015] Preferably, the selection method also includes: determining the extension amount of the plunger in the column according to the model of the selected hydraulic support and the height of the tunnel; determining the stiffness of the selected hydraulic support according to the extension amount of the plunger in the column; and determining the timing of initial support according to the initial support force, working resistance and the stiffness of the selected hydraulic support and the support balance point of the surrounding rock-support mutual feedback balance curve under the second equivalent ground stress, wherein the second equivalent ground stress is the equivalent ground stress suffered by the tunnel in the non-mining influence area.

[0016] The selection method also includes: determining the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress and the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress. Correspondingly, the determination of the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress includes: when the surrounding rock-support mutual feed balance curve under the first equivalent ground stress does not have an extreme point, using the surrounding rock separation control condition to determine the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress; or when the surrounding rock-support mutual feed balance curve under the first equivalent ground stress has an extreme point, determining the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress. The extreme point of the frame mutual feed balance curve is the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress, and the determination of the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress includes: according to the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress and the surrounding rock-support mutual feed balance curve under the second equivalent ground stress, determining the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress, wherein the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress is equal to the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress.

[0017] Through the above technical solution, the present invention creatively determines the residual impact energy required to be absorbed by the hydraulic support to be selected based on the residual impact energy determination method; then, based on the residual impact energy required to be absorbed by the hydraulic support, the hydraulic support matching the roadway is determined. The present invention can achieve accurate selection of roadway anti-impact hydraulic supports based on the residual impact energy required to be absorbed by the hydraulic support.

[0018] The third aspect of the present invention provides a system for determining residual impulse energy, the determination system comprising: an energy consumption determination device for determining the total energy consumption of the resistance zone of the surrounding rock according to the damage variables of the coal rock in the softening zone and the damage variables of the coal rock in the crushing zone of the surrounding rock of the tunnel, the equivalent radius of the tunnel space, the radius of the crushing zone and the radius of the softening zone, wherein the resistance zone includes the crushing zone and the softening zone; a kinetic energy determination device for determining the total energy consumption of the resistance zone of the surrounding rock according to the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the radius of the softening zone, the equivalent radius of the tunnel space, and the radius of the softening zone. diameter and the average density of the coal rock in the resistance zone to determine the kinetic energy generated by the impact of the resistance zone; and a state determination device for determining the stable state of the tunnel under the first equivalent ground stress, wherein the first equivalent ground stress is the equivalent ground stress to which the tunnel in the mining influence zone is subjected; and a residual impact energy determination device for determining the residual impact energy that the to-be-selected hydraulic support needs to absorb based on the stable state of the tunnel 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 anchoring support in the tunnel.

[0019] The system for determining residual impulse energy has the same advantages as the method for determining residual impulse energy described above over the prior art, and will not be described in detail here.

[0020] The fourth aspect of the present invention provides a hydraulic support selection system, which includes: a residual impulse energy determination system for determining the residual impulse energy required to be absorbed by the hydraulic support to be selected; and a support determination device for determining the hydraulic support that matches the tunnel based on the residual impulse energy required to be absorbed by the hydraulic support.

[0021] The advantages of the hydraulic support selection system and the hydraulic support selection method described above over the prior art are the same, and will not be described in detail here.

[0022] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying 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 detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the transmission process of rock burst energy in a tunnel under high-energy mine tremors.

[0025] Figure 2 is a flow chart of a method for determining support strength provided by one embodiment of the present invention;

[0026] Figure 3 It is a schematic diagram of the working surface and its leading stress concentration area;

[0027] Figure 4 It is a schematic diagram of the mining stress peak in the surrounding rock and its original rock stress distribution;

[0028] Figure 5 is a flow chart for determining a first surrounding rock-support mutual feeding equilibrium curve under the first equivalent ground stress provided by an embodiment of the present invention;

[0029] Figure 6 This is a Type I curve of the mutual feedback balance characteristic of "surrounding rock-support" in a roadway provided by an embodiment of the present invention;

[0030] Figure 7 This is a Type II curve of the mutual feedback balance characteristic of "surrounding rock-support" in the advanced tunnel provided by an embodiment of the present invention;

[0031] Figure 8 is a flow chart of a method for determining residual impulse energy provided by one embodiment of the present invention;

[0032] Figure 9 is a flow chart of a selection method provided by an embodiment of the present invention; and

[0033] Figure 10 It is a tunnel "surrounding rock-support" mutual feedback balance characteristic curve under specific ground stress provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0035] The overall idea of the present invention is to establish a mechanical analysis model for the occurrence of rock burst in the tunnel, derive and draw the "surrounding rock-support" mutual feedback balance equation and characteristic curve of the tunnel under the action of ground stress; based on this, determine whether there is an extreme point of dynamic instability in the tunnel, and if so, further determine the critical support stress and its corresponding critical surrounding rock displacement, surrounding rock critical softening radius and other parameters; calculate and determine the maximum energy released after the occurrence of rock burst in the tunnel; and guide the selection of anti-impact hydraulic supports according to the anti-impact support strength design principle and the energy conservation principle respectively.

[0036] The tunnel includes the surrounding rock and the tunnel space formed by the surrounding rock (the equivalent radius is ρ0), such as Figure 1 As shown. Among them, the surrounding rock of the tunnel includes elastic zone, softening zone (radius is ρ p ) and the crushing zone (radius ρ d ).,like Figure 1Based on the disturbance response instability theory of rock burst, for a given coal-rock deformation system (tunnel), under the action of the second equivalent ground stress P2 (or the first equivalent ground stress P1), the radius of the plastic softening zone (hereinafter referred to as the softening zone) is ρ P2 (or ρ P1 ),like Figure 4 shown.

[0037] The following description will be made using two embodiments as examples, but is not limited to the following two embodiments. First, the basic situation of the two embodiments is introduced, and then, by way of comparison, the process of determining the support strength, residual energy and selection of the hydraulic support in the two embodiments is specifically described.

[0038] Example 1:

[0039] Under the mining action of the working face (P1=24.76MPa), there is no dynamic instability point in the near-field surrounding rock of the tunnel (the impact disaster energy is only the energy of the far-field disturbance source point).

[0040] The coal seam at a certain mine is nearly horizontal. The roadway ahead of the working face for the anti-bumping support design has a rectangular cross-section, 3.2m high and 4.4m wide (i.e., roadway width). The equivalent circular radius of the circumscribed circle of the rectangular roadway (i.e., the equivalent radius of the roadway space) is 2.7m (determined below). The number of anchor cables in a row is 5, and the number of anchor rods in a row is 9. The active support for this roadway is anchor mesh cable support, which is used to enhance the roadway's anti-bumping and anti-bumping capabilities.

[0041] The equivalent radius ρ0 of the tunnel space (e.g., the circumscribed circle radius of a rectangular tunnel, ρ0 = 2.70 m) can be determined based on the main rock mechanical parameters of the tunnel surrounding rock. The rock mechanical parameters may include the uniaxial compressive strength σ c =11.60 MPa, elastic modulus E = 2780 MPa, coal rock impact tendency index K = λ1 / E = 1.10, residual degeneration modulus λ2 = 14 MPa, residual strength coefficient ξ = 0.22, Poisson's ratio υ = 0.25; where λ1 is the softening degeneration modulus of coal rock (MPa). The main parameters of the roadway and its surrounding rock can be found in Table 1.

[0042] Table 1 Main physical and mechanical parameters of the tunnel and its surrounding rock

[0043]

[0044] Example 2:

[0045] During mining at the working face, dynamic instability points appeared in the near-field surrounding rock of the tunnel under the action of mining stress (P1=47.62MPa) (the impact disaster energy of the tunnel surrounding rock includes the energy of the far-field disturbance source point and the dynamic instability energy of the near-field surrounding rock).

[0046] The cross-section of the 513 working face tunnel of a certain mine is nearly circular, the span of the coal seam mining tunnel space (i.e. the width of the tunnel space) is 5.2m, and the height is 3.8m.

[0047] (1) The original support form of the 513 outer section working face.

[0048] The support form of the two drifts of the 513 outer section working face is a combined support of anchor nets (ropes) and scaffoldings; three-section U-shaped steel scaffoldings are used, with each U-shaped steel scaffolding having two overlaps, and four pairs of clips are used for each overlap; and a bottom arc seal is added, with each U-shaped steel bottom arc having four overlaps, and four pairs of clips are used for each overlap; the spacing between scaffoldings in coal lanes and semi-coal-rock lanes is 500mm; the specifications of the anchor rods on both sides are: φ22×2400mm, the spacing between rows is 800×1000mm, and the number of anchor rods is 8; the specifications of the roof anchor cables are: φ21.6×8200mm, the spacing between rows is 800×1000mm, and the number of anchor cables is 6.

[0049] (2) Constant resistance anchor cable reinforcement support in the two drifts of the 513 outer section working face.

[0050] Prior to mining, high-preload, constant-resistance, high-deformation anchor cables were used to reinforce the transport and return air chute of the outer section of the 513 working face, extending 300 meters ahead. Grouting anchor cables were also used to increase the overall self-bearing capacity of the surrounding rock, enabling it to adapt to large deformations in the roadway and thus improving its impact resistance. During mining, the work progressed gradually, ensuring that the reinforced support distance was no less than 300 meters. Construction of the transport chute began at the cutout and ended 20 meters outward from the intersection of the transport chute and the material road. Construction of the return air chute began at the cutout and ended 20 meters outward from the intersection of the return air chute and the material road. Furthermore, energy-absorbing and anti-impact supports were used to reinforce the support of both chute 200 meters ahead during mining.

[0051] The equivalent radius of the roadway space ρ0 = 2.59 m can be determined based on the main rock mechanical parameters of the surrounding rock of the 513 working face mining roadway; the rock physical and mechanical parameters may include the uniaxial compressive strength σ c =12.82 MPa, elastic modulus E = 2940 MPa, coal rock impact proneness index K = 1.86, residual drop modulus λ2 = 15, residual strength coefficient ξ = 0.24, and Poisson's ratio υ = 0.25. Assuming that unloading the surrounding rock only changes the mining stress distribution and ignoring the coupling effects between multiple anti-bumping technologies, the main parameters of the roadway and its surrounding rock for the anti-bumping support design of the 513 working face are detailed in Table 2.

[0052] Table 2 Main parameters of the mining roadway and its surrounding rock in the 513 working face of a mine

[0053] Serial number Main control parameter name symbol unit Parameter statistics 1 Coal rock impact energy index K — 1.86 2 Uniaxial compressive strength of coal rock <![CDATA[σ c ]]> MPa 12.82 3 Coal rock elastic modulus E Mpa 2940 4 internal friction angle Φ ° 30 5 Residual modulus <![CDATA[λ2]]> MPa 15 6 Residual strength coefficient ξ — 0.24 7 Poisson's ratio υ — 0.25 8 Lane radius <![CDATA[ρ0]]> m 2.59 9 In situ rock stress <![CDATA[P1]]> MPa 42.27 10 Mining stress concentration factor of working face λ — 1.85 11 Surrounding rock pressure relief efficiency coefficient <![CDATA[W drill ]]> — 0.6057 12 Equivalent ground stress of tunnel in non-mining affected area <![CDATA[P2]]> MPa 24.76 13 Equivalent ground stress of roadway in mining-affected area <![CDATA[P1]]> MPa 47.62

[0054] Figure 2FIG. 1 is a flow chart of a method for determining support strength according to an embodiment of the present invention. Figure 2 As shown, the determination method may include the following steps S201-S204.

[0055] Step S201: determining the first equivalent ground stress of the roadway in the mining influence area.

[0056] Wherein, the non-mining influence zone roadway refers to the roadway without the influence of mining, the mining influence zone roadway refers to the roadway under the influence of mining, and the non-mining influence zone roadway and the mining influence zone roadway refer to the same roadway. The first equivalent ground stress P1 can be determined by any existing method (Example 1: as Figure 4 Or as shown in 6, P1 = 24.76MPa; Example 2: Figure 7 As shown, P1 = 47.62 MPa).

[0057] At the same time, the determination method also includes: determining the second equivalent ground stress of the tunnel in the non-mining influence area.

[0058] Specifically, determining the first equivalent in-situ stress of the roadway in the mining-affected zone and the second equivalent in-situ stress of the roadway in the non-mining-affected zone may include the following three steps.

[0059] First, according to the original rock stress P0, the uniaxial compressive strength of coal rock σ c And the following formula (1-1) is used to determine the mining stress peak value P in the surrounding rock of the roadway in the non-mining affected area m ,

[0060]

[0061] Then, according to the mining stress peak value P m , surrounding rock pressure relief efficiency coefficient W drill , the uniaxial compressive strength of the coal rock σ c And the following formula (1-2) is used to determine the second equivalent ground stress (i.e., the equivalent ground stress of the roadway in the non-mining affected area) P2,

[0062]

[0063] Finally, according to the mining stress peak value P m , surrounding rock pressure relief efficiency coefficient W drill , the mining stress concentration coefficient λ of the roadway in the mining-affected area m , the uniaxial compressive strength of the coal rock σ c And the following formula (1-3) is used to determine the first equivalent ground stress (i.e., the equivalent ground stress P1 of the roadway in the mining influence area).

[0064]

[0065] Of course, there is no particular order in the steps of determining the first equivalent geostress and the second equivalent geostress.

[0066] For Example 1: First, P0 = 14 MPa, σ c =11.60MPa (as shown in Table 1) and the above formula (1-1) to determine the mining stress peak value P in the surrounding rock of the roadway in the non-mining affected area m (like Figure 4 Or as shown in 6, P m =23.9MPa). Then, combined with P m =23.9MPa, W drill =1 and σ c =11.60MPa (as shown in Table 1), the equivalent ground stress P2 of the roadway in the non-mining affected area is determined by using the above formula (1-2) Figure 4 Or as shown in 6, P2=P0=14MPa). Finally, combined with P m =23.9MPa, W drill =1,λ m =1.3138,σ c =11.60MPa and the above formula (1-3), determine the roadway in the mining affected area (such as Figure 3 The equivalent ground stress P1 of the tunnel A shown in FIG Figure 4 Or as shown in 6, P1 = 24.76MPa).

[0067] For Example 2, first, P0 = 42.27 MPa, σ c =12.82MPa (as shown in Table 1) and the above formula (1-1) to determine the mining stress peak value P in the surrounding rock of the roadway in the non-mining affected area m (like Figure 4 Or as shown in 6, P m =66.61MPa). Then, combined with P m =66.61MPa, W drill =0.6057 and σ c =12.82MPa (as shown in Table 1), the equivalent ground stress P2 of the roadway in the non-mining affected area is determined using the above formula (1-2) Figure 4 Or as shown in 6, P2=24.76MPa). Finally, combined with P m =66.61MPa, W drill =0.6057,λ m =1.85,σ c =12.82MPa and the above formula (1-3), determine the roadway in the mining affected area (such as Figure 3 The equivalent ground stress P1 of the tunnel A shown in FIG Figure 7In step S202, a first surrounding rock-support mutual feedback balance curve under the first equivalent in-situ stress is determined based on the system equation of the roadway, the functional relationship between the displacement of the surrounding rock of the roadway and the radius of the crushing zone, the first equivalent in-situ stress, the functional relationship between the first boundary stress of the crushing zone to the softening zone under the first equivalent in-situ stress, the first support strength required for the roadway space, and the radius of the crushing zone.

[0068] Regarding step S202, determining the first surrounding rock-support mutual feeding equilibrium curve under the first equivalent ground stress may include the following steps S501-S502, such as Figure 5 shown.

[0069] Step S501: determining the first boundary stress corresponding to the first equivalent ground stress according to the system equation of the tunnel.

[0070] The system equations for the roadway are shown below:

[0071]

[0072] Among them, m is the intermediate variable, is the internal friction angle of the surrounding rock; p d-p is the boundary stress of the crushing zone to the softening zone (MPa) (which may be equal to the first boundary stress); P is the ground stress of the roadway (which may be equal to the first equivalent ground stress P1) (MPa); ρ d is the radius of the crushing zone (m), ρ p is the radius of the softening zone (m), and k is a constant. Equation (2) above indicates that the boundary stress between the crushing zone and the softening zone changes with changes in the in-situ stress. Specifically, the first equivalent in-situ stress P1 can be substituted into Equation (2) to determine the corresponding first boundary stress.

[0073] Step S502: determining the first surrounding rock-support mutual feed balance curve based on the first boundary stress, the functional relationship between the first boundary stress and the first support strength and the crushing zone radius, and the functional relationship between the displacement of the surrounding rock of the tunnel and the crushing zone radius.

[0074] The functional relationship between the displacement of the surrounding rock of the tunnel and the radius of the crushing zone is:

[0075]

[0076] Among them, u a is the displacement of the surrounding rock of the tunnel (m); σ c is the uniaxial compressive strength; ρ dis the radius of the crushing zone of the surrounding rock (m); ρ0 is the equivalent radius of the tunnel space (m); λ1 is the softening modulus of the coal rock (MPa); E is the elastic modulus of the coal rock (GPa); and ξ is the residual strength coefficient.

[0077] First, determine the first boundary stress shown in the following formula (4) and the first support strength p required for the tunnel space: sum and the radius of the crushing zone ρ d The functional relationship between the two is:

[0078]

[0079] in, ρ0 is the equivalent radius of the tunnel space; p sum is the total support strength of the support equipment in the tunnel (MPa); q is an intermediate variable, is the internal friction angle of the surrounding rock in the crushed zone. The above formula (4) shows that as the boundary stress of the crushed zone to the softened zone changes, the support strength required for the tunnel space changes.

[0080] Then, combining the first boundary stress and formulas (3)-(4) together, the first support strength p required for the tunnel space with an equivalent radius ρ0 can be obtained: sum The displacement u of the surrounding rock of the roadway a The functional relationship between (not listed) (i.e., the first surrounding rock-support mutual feed balance curve, such as Figure 6 The curve corresponding to P1 shows that the ground stress P1 is related to the first support strength p sum Under the joint action of d The crushing zone with radius ρ p The softening zone is in equilibrium.

[0081] While executing step S202, a second surrounding rock-support mutual-feed balance curve under the second equivalent in-situ stress may also be determined. The determination method may further include determining the second surrounding rock-support mutual-feed balance curve under the second equivalent in-situ stress based on a system equation of the roadway, a functional relationship between the displacement of the surrounding rock of the roadway and the radius of the crushing zone, the second equivalent in-situ stress, a functional relationship between the second boundary stress of the crushing zone to the softening zone under the second equivalent in-situ stress, a second support strength required for the space formed by the roadway, and the radius of the crushing zone.

[0082] Among them, determining the second surrounding rock-support mutual feedback equilibrium curve under the second equivalent ground stress may include: determining the second boundary stress corresponding to the second equivalent ground stress according to the system equation of the tunnel; and determining the second surrounding rock-support mutual feedback equilibrium 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 tunnel and the radius of the crushing zone, and the functional relationship between the displacement of the surrounding rock of the tunnel and the radius of the crushing zone.

[0083] 1. Specifically, the second boundary stress corresponding to the second equivalent ground stress as shown in formula (2) can be determined. Wherein, P is the ground stress of the roadway (which can be equal to the second equivalent ground stress P2) (MPa). Then, the second support strength p required for the space formed by the second boundary stress and the roadway as shown in formula (4) is determined. sum and the radius of the crushing zone ρ d Finally, combining the second boundary stress and formulas (3)-(4) together, the second support strength p required for the tunnel space with an equivalent radius ρ0 can be obtained: sum The displacement u of the surrounding rock of the roadway a The functional relationship between (not listed) (i.e., the second surrounding rock-support mutual feed balance curve, such as Figure 6 The curve corresponding to P2 shows that the ground stress P2 is related to the second support strength p sum Under the joint action of d The crushing zone with radius ρ p The softening zone is in equilibrium.

[0084] That is, by combining equations (2), (3) and (4), the “surrounding rock-support” mutual feedback equilibrium curve under the control of the second equivalent in-situ stress P1 and the first equivalent in-situ stress P1 is plotted. Then, in step S203, it is determined whether the surrounding rock-support mutual feedback equilibrium curve under the control of the first equivalent in-situ stress P1 has an extreme point S0 that represents the impact instability of the surrounding rock of the roadway (such as the corresponding extreme point S0 in the second embodiment). Figure 7 As shown): If there is no extreme point S0 of dynamic instability, it is called the I-type curve of the mutual feedback balance characteristic of the tunnel "surrounding rock-support" (such as the corresponding Figure 6 For example, in the working face tunnel with rectangular cross section in the first embodiment, there is no extreme point. The anti-bumping support design should consider the effect of far-field disturbance source. Otherwise, it is called type II curve (such as the corresponding curve in the second embodiment). Figure 7 As shown), for example, in the mining tunnel of the 513 working face of a mine in Example 2, there is an extreme point. The anti-bumping support design must take into account the impact of the near-field surrounding rock and fully consider the superposition of the disturbance of the far-field mine earthquake load and energy.

[0085] Step S203: determining a first support balance point of the first surrounding rock-support mutual feed balance curve.

[0086] Regarding step S203, the determining of the first support balance point of the first surrounding rock-support mutual feeding balance curve may include any one of the following two situations.

[0087] Case 1 (Example 1): When there is no extreme point in the first surrounding rock-support mutual feeding balance curve, the first support balance point is determined according to the first surrounding rock-support mutual feeding balance curve using the surrounding rock separation control condition.

[0088] 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 may be any one of 0-6% (or any one of 0-9%).

[0089] Case 2 (Example 2): When there is an extreme point in the first surrounding rock-support mutual feeding balance curve, the extreme point of the first surrounding rock-support mutual feeding balance curve is determined as the first support balance point.

[0090] Then, the second support balance point of the second surrounding rock-support mutual feed balance curve may be determined according to the first support balance point.

[0091] The determination method may further include determining a second support balance point of the second surrounding rock-support mutual feed balance curve. Accordingly, determining the second support balance point of the second surrounding rock-support mutual feed balance curve includes determining the second support balance point based on the ordinate of the first support balance point and the second surrounding rock-support mutual feed balance curve. The ordinate of the first support balance point is equal to the ordinate of the second support balance point.

[0092] The following describes the specific process of how to determine the first support balance point and the second support balance point for the above two situations respectively.

[0093] For the first case (Example 1): If the surrounding rock-support mutual feedback equilibrium curve under the control of the first equivalent ground stress P1 does not have an extreme point S0 (such as Figure 6 As shown in Figure 1, the I-type curve, that is, the tunnel does not have the possibility of dynamic instability under high static load conditions), and the abscissa (displacement of the surrounding rock) of a certain point N1 on the first surrounding rock-support mutual feed balance curve meets the surrounding rock separation control condition (for example, the preset ratio is 4.18%), then the point N1 (u2 = 0.1129m, p sum=0.43949MPa) is 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).

[0094] For the second case (Example 2): If the surrounding rock-support mutual feedback balance curve under the control of the first equivalent ground stress P1 has an extreme point S0 (such as Figure 7 As shown in Figure 1, a Type II curve indicates that the roadway has the potential for dynamic instability under high static load conditions. Therefore, the extreme point S0 (0.57 m, 0.68 MPa) is determined as the first support balance point. Since the ordinates of the first and second support balance points are equal, the second support balance point N0 (0.08 m, 0.68 MPa) can be determined.

[0095] Step S204: 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 anchor support of the tunnel.

[0096] According to the vertical coordinate p of the first support balance point sum , the stress p of the anchor support of the tunnel bolt And the following formula (5) determines the support strength p s-static :

[0097] p s-static =(p sum -ω1p bolt ) / ω2, (5)

[0098] Among them, ω1 and ω2 are the synergy coefficients of anchor support and hydraulic support support strength respectively. Further, it can be determined that the constant resistance support strength of the hydraulic support when the absorption and concession is started is p s-dyn =mp s-static , m is the energy absorber support resistance gain coefficient (m can range from 1.0 to 1.5, and can be 1.3 here). Specifically, p s-dyn =1.3×0.3619=0.47047MPa.

[0099] Specifically, for Figure 6 The surrounding rock-support mutual feedback balance curve (I-type curve) shown can determine the support strength p s-static is 0.3619MPa; while for Figure 7 The surrounding rock-support mutual feedback balance curve (Type II curve) shown can determine the support strength p s-static It is 0.27Mpa.

[0100] For the above-mentioned embodiment 1, although there is no dynamic instability point in the surrounding rock near the tunnel under the action of P1 = 24.76MPa, an instability point will appear as P1 increases to a certain value. The specific determination process is the same as the process of the corresponding instability point in embodiment 2. For embodiment 2, under the action of P1 = 47.62MPa, a dynamic instability point (i.e., the first instability point) appears in the surrounding rock near the tunnel. As the ground stress P1 increases to a certain value (e.g., P3), a new instability point (i.e., the second instability point) will appear. Figure 10 As shown, the specific determination process is the same as the corresponding instability point process in the second embodiment.

[0101] In summary, the present invention creatively determines the first surrounding rock-support mutual feedback balance curve under the first equivalent ground stress based on the system equation of the tunnel, the functional relationship between the displacement of the surrounding rock of the tunnel and the radius of the crushing zone, the first equivalent ground stress and the first boundary stress of the crushing zone to the softening zone under the first equivalent ground stress, the first support strength required by the tunnel space, and the radius of the crushing zone; determines the first support balance point of the first surrounding rock-support mutual feedback balance curve; and determines the support strength of the hydraulic support to be selected for the surrounding rock based on the first support balance point and the stress of the anchor support of the tunnel. The present invention takes into account the loading effect of the mining of the working face on the advance tunnel, and can quantitatively determine the deformation coordination response and mutual feedback balance relationship of the "surrounding rock and support" of the rock burst tunnel. Therefore, the support strength of the hydraulic support to be selected for the surrounding rock can be accurately determined, and then the parametric selection of tunnel anti-impact hydraulic supports can be achieved based on the support strength.

[0102] Engineering practice has shown that high-strength tunnel support can help increase the critical load for rock burst initiation, making rock burst less likely to occur or more difficult to occur. Therefore, tunnel support design technology aimed at preventing rock burst before it initiates has naturally become an important aspect of coal mine rock burst prevention and control.

[0103] An embodiment of the present invention further provides a method for selecting a hydraulic support. The selection method may include: determining 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 according to the support strength determination method; determining the minimum required expansion and contraction amount of the active column in the column of the hydraulic support according to the first support balance point and the second support balance point; and determining the hydraulic support that matches the roadway according to the support strength of the hydraulic support for the surrounding rock and the minimum required expansion and contraction amount of the active column in the column.

[0104] Specifically, for the first embodiment, the minimum expansion and contraction amount required for the active column in the column can be determined based on the horizontal coordinate u1 of the second support balance point N0 and the horizontal coordinate u2 of the first support balance point N1:min =2(u2-u1)=2×(0.1129m-0.03773m)=150.34mm. For the second embodiment, the horizontal coordinate u of the second support balance point N0 can be used as the basis. a1 and the horizontal coordinate u of the first support balance point S0 a2 , it can be determined that the minimum expansion and contraction required by the active column in the column is: L min =2(u a2 -u a1 )=2×(0.57m-0.08m)=980mm.

[0105] Among them, determining the hydraulic support that matches the tunnel may include: determining the static load working load and absorption and concession resistance required for the hydraulic support to prevent impact based on the support strength of the hydraulic support for the surrounding rock; and selecting the model of the hydraulic support based on the static load working load and absorption and concession resistance required for the hydraulic support to prevent impact and the minimum expansion and contraction amount required for the active column in the column.

[0106] Specifically, according to the support strength p of the hydraulic support to the surrounding rock s-static , the distance l0 between any two adjacent hydraulic supports, the width B of the lane and F s-static =l0Bp s-static , determine the static load F required for the hydraulic support anti-collision s-static Then, according to the static load F required for the hydraulic support anti-collision s-static and F s-dny =mF s-static , the absorption and yield resistance F required for the hydraulic support to prevent impact can be determined s-dny .

[0107] For the two-column guide rod unit type energy-absorbing and anti-impact hydraulic support, the distance between any two adjacent hydraulic supports is l0 = 2.5m, the roadway width B = 4.4m, and the support strength p of the hydraulic support to the surrounding rock is s-static = 0.3619Mpa (for the tunnel in Example 1), calculate the static load F required for the support to prevent impact s-static =3980.9kN; and the absorption and displacement resistance F required for the hydraulic support to prevent impact s-dny =mF s-static =1.3×3980.9kN=5175.17kN.

[0108] According to Table 3, the working resistance F of the hydraulic support w is 3300kN and the absorption and yield resistance F n 3750kN. Due to the static load required for the support to prevent impact (F s-static=3980.9kN) is greater than the working resistance of the hydraulic support (F w =3300kN) and the required absorption and yield resistance (F s-dny =5175.17kN) is greater than the hydraulic support's absorption and yield resistance (F n =3750kN), so it can be concluded that the two-column guide rod unit type energy-absorbing and anti-impact hydraulic support cannot meet the energy-absorbing and anti-impact requirements of the current tunnel.

[0109] Table 3 Parameters of two-column guide rod unit type energy-absorbing hydraulic support

[0110]

[0111] For the two-column guide-rod-free unit type energy-absorbing and impact-resistant hydraulic supports, the distance between any two adjacent hydraulic supports is l0 = 2.4m, the roadway width B = 4.4m, and the support strength p of the hydraulic supports on the surrounding rock is s-static = 0.3619 MPa (for the tunnel in Example 1), calculate the static load F required for the support to prevent impact s-static =3821.7kN; and the absorption and displacement resistance F required for the hydraulic support to prevent impact s-dny =mF s-static =1.3×3821.7kN=4968.21kN.

[0112] According to Table 4, the working resistance F of the hydraulic support w is 4000kN and the absorption and yield resistance F n 6000kN. Due to the static load required for the support to prevent impact (F s-static =3821.7kN) is less than the working resistance of the hydraulic support (F w =4000kN) and the required absorption and yield resistance (F s-dny =4968.21kN) is less than the hydraulic support's absorption and yield resistance (F n =6000kN), so it can be concluded that the two-column guide rod-free unit type energy-absorbing and anti-impact hydraulic support can meet the energy-absorbing and anti-impact requirements of the current tunnel.

[0113] According to Table 4, the plunger pressure relief stroke L sta 1900mm. Due to the minimum expansion and contraction required by the active column in the column (L min =150.34mm) is less than the piston pressure stroke (L sta =1900mm). The above criteria show that the two-column guide-rod-free unitary energy-absorbing and anti-impact hydraulic support meets the current requirements for anti-impact and energy-absorbing in tunnels in terms of working resistance of impact yielding, absorption and yielding resistance, and active column pressure yielding stroke.

[0114] Table 4 Parameters of two-column unit type energy-absorbing hydraulic support without guide rods

[0115]

[0116] For the portal energy-absorbing and anti-impact hydraulic supports, the distance between any two adjacent hydraulic supports is l0=5m, the tunnel width B=5.2m, and the support strength p of the hydraulic supports on the surrounding rock is s-static = 0.27 MPa (for the tunnel in Example 2), calculate the static load F required for the support to prevent impact s-static =7020kN. Working resistance F of the gantry support w-static is 6600kN, so the static load required for the support to prevent impact (F s-static =7020kN) is greater than the working resistance of the portal support (F w-static =6600kN). The above criteria show that the use of portal energy-absorbing supports alone cannot meet the resistance requirements of anti-impact support.

[0117] Furthermore, for the combination of a portal energy-absorbing and anti-collision hydraulic support and a stack-type energy-absorbing support (for example, the anti-collision and anti-collision applicability of a stack-type support is interspersed between portal supports, which can be called a support combination), the static load F required for support anti-collision can be calculated similarly. s-static =7020kN. Working resistance of gantry support F w-static1 The working resistance F of the stack support is 6600kN. w-static2 is 4000kN, so the static load required for the support to prevent impact (F s-static =7020kN) is less than the total working resistance of the portal support and the stack support (F w-static =10600kN).

[0118] Therefore, the above combined support design meets the strength and anti-collision requirements, and the anti-collision safety factor N can also be obtained. s =F w-static / F s-static =1.51.

[0119] For the combination of door-type energy-absorbing and anti-impact hydraulic support and stack-type energy-absorbing support (i.e. support combination), the plunger pressure stroke L sta To ensure the impact energy absorption stroke, the static pressure support column piston pressure stroke is calculated to see whether it meets the maximum deformation of the roadway static pressure. The judgment criteria are as follows: Due to the minimum expansion and contraction required by the piston in the column (L min =980mm) is less than the piston pressure stroke (L sta=1300mm), as shown in Table 5. The above criteria show that the combination of the portal energy-absorbing and anti-impact hydraulic support and the stack-type energy-absorbing support meets the current requirements for anti-impact and energy-absorbing tunnels in terms of impact-yielding working resistance, absorption-yielding resistance, and piston pressure-yielding stroke.

[0120] Table 5 Design parameters of mining tunnel support and anti-bumping safety factor

[0121] Serial number Tunnel support parameters symbol unit Calculated value 1 <![CDATA[Support stress at the instability point S0]]> <![CDATA[P scr ]]> MPa 0.68 2 <![CDATA[In-stability point S0 roadway rib displacement]]> <![CDATA[u a2 ]]> m 0.57 3 <![CDATA[Inbye displacement at the balance point N0]]> <![CDATA[u a1 ]]> m 0.08 4 Anchorage and O-type shed support strength <![CDATA[P other ]]> MPa 0.39 5 Support strength under static pressure <![CDATA[p s-static ]]> MPa 0.27 6 Anchor mesh support coordination coefficient <![CDATA[ω1]]> — 1.20 7 Hydraulic support support coordination coefficient <![CDATA[ω2]]> — 0.80 8 Minimum displacement of the plunger under static load <![CDATA[L min ]]> m 0.98 9 Radius of critical crushing zone for surrounding rock instability <![CDATA[ρ dcr ]]> m 16.32 10 Radius of critical softening zone for surrounding rock instability <![CDATA[ρ pcr ]]> m 19.37 11 Energy consumption in surrounding rock softening and crushing zone <![CDATA[E rock ]]> J / m 4.11E+06 12 Energy absorption of a single ordinary anchor <![CDATA[E ubolt ]]> J 2.08E+04 13 Energy absorption of a single ordinary anchor cable <![CDATA[E ucable ]]> J 1.28E+05 14 Energy absorption of a single constant resistance anchor cable <![CDATA[E ubolt-con ]]> J 5.25E+04 15 Energy absorption of anchor support per meter of tunnel <![CDATA[E bolt-cable ]]> J / m 4.71E+05 16 The most dangerous energy release magnitude <![CDATA[ML max ]]> — 2.27 17 The most dangerous energy release <![CDATA[E max ]]> J 7.7E+07 18 Vibration energy 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 rack spacing <![CDATA[l0]]> m 5.00 21 Tunnel support width B m 5.20 22 Minimum static working resistance of the bracket <![CDATA[F s-static ]]> kN 7020 23 Working resistance of the selected bracket <![CDATA[F w-static ]]> kN 10600 24 Residual energy of surrounding rock <![CDATA[E residual ]]> J / m 2.03E+05 25 Energy absorption required for tunnel supports <![CDATA[E support ]]> J 1.02E+06 26 Total energy absorption of the selected bracket <![CDATA[E imp ]]> J 1.66E+06 27 Minimum yield stroke of energy absorber <![CDATA[L str ]]> m 0.74 28 Minimum retraction of piston <![CDATA[L min ]]> m 0.98 29 Anti-collision safety factor <![CDATA[N s ]]> — 1.51 30 Stop safety factor <![CDATA[N e ]]> — 1.63

[0122] The selection method also includes: determining the extension amount of the plunger in the column according to the model of the selected hydraulic support and the height of the tunnel; determining the stiffness of the selected hydraulic support according to the extension amount of the plunger in the column; and determining the initial support timing according to the initial support force, working resistance and stiffness of the selected hydraulic support and the second support balance point.

[0123] Specifically, according to the model of the two-column guide-rod-free unit-type anti-collision support, the support height (for example, 2.6m) is determined; the roadway height to be supported H = 3.2m is subtracted from the determined support height (for example, 2.6m) to obtain the active column extension h = 0.6m in the column; further, according to the active column extension h = 0.6m, the support stiffness K can be determined. support =2.33×10 7 N / m; combined with the initial support force F of the bracket initiate =3090kN (see Table 4 for details), the working resistance of the bracket F w , the stiffness value K of the bracket support , the horizontal coordinate of the second support balance point (i.e., the displacement of the tunnel surrounding rock corresponding to the support balance point N0 under the action of the second equivalent ground stress P2) u1 and the following formula, determine the initial support timing (i.e., the initial support surrounding rock displacement) u0,

[0124]

[0125] Similarly, the mean stiffness K of the bracket combination can be determined support Equal to 2.33×10 7 N / m; initial support force F of the combined support initiate =8070kN, working resistance of the support assembly F w-static The stiffness value K of the combination with the bracket support , the horizontal coordinate of the second support balance point (i.e., the displacement of the tunnel surrounding rock corresponding to the balance point N0 of the tunnel support under the action of the second equivalent ground stress P2) u a1 The following formula is used to determine the initial support timing, that is, the initial support surrounding rock displacement u a0 :

[0126]

[0127] One embodiment of the present invention also provides a support strength determination system. The determination system may include: a stress determination device for determining the second equivalent ground stress of the non-mining influence zone roadway and the first equivalent ground stress of the mining influence zone roadway; a balance curve determination device for determining the first surrounding rock-support mutual feed balance 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 crushing zone, the functional relationship between the first equivalent ground stress and the first boundary stress of the crushing zone to the softening zone under the first equivalent ground stress, the first support strength required by the roadway space, and the radius of the crushing zone; a balance point determination device for determining the first support balance point of the first surrounding rock-support mutual feed balance 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 anchor support of the roadway.

[0128] Preferably, the balance point determination device is used to determine the first support balance point of the first surrounding rock-support mutual feed balance curve, including: when there is no extreme point in the first surrounding rock-support mutual feed balance curve, determining the first support balance point according to the first surrounding rock-support mutual feed balance curve using the surrounding rock separation control condition; or when there is an extreme point in the first surrounding rock-support mutual feed balance curve, determining the extreme point of the first surrounding rock-support mutual feed balance curve as the first support balance point.

[0129] Preferably, the balance point determination device is also used to determine the second support balance point of the second surrounding rock-support mutual feed balance curve. Accordingly, the determination of the second support balance point of the second surrounding rock-support mutual feed balance curve includes: determining the second support balance point according to the vertical coordinate of the first support balance point and the second surrounding rock-support mutual feed balance curve, wherein the vertical coordinate of the first support balance point is equal to the vertical coordinate of the second support balance point.

[0130] For specific details and benefits of the support strength determination system provided by the present invention, please refer to the above description of the support strength determination method, which will not be repeated here.

[0131] One embodiment of the present invention further provides a hydraulic support selection system. The selection system may include: a support strength determination system for determining 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; an expansion and contraction amount determination device for determining the minimum expansion and contraction amount required for the active column in the hydraulic support column based on the first support balance point and the second support balance point; and a hydraulic support determination device for determining the hydraulic support that matches the roadway based on the support strength of the hydraulic support for the surrounding rock and the minimum expansion and contraction amount required for the active column in the column.

[0132] The specific details and benefits of the hydraulic support selection system provided by the present invention can be found in the description of the hydraulic support selection method described above, and will not be repeated here.

[0133] 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 based on the support strength determination method; determines the minimum required expansion and contraction of the active column in the hydraulic support's columns based on the first and second support balance points; and then determines the hydraulic support that matches the roadway based on the support strength of the hydraulic support for the surrounding rock and the minimum required expansion and contraction of the active column in the column. The present invention enables precise selection of roadway anti-collision hydraulic supports based on the quantitative support strength required by the surrounding rock.

[0134] The existing energy-absorbing and anti-impact support design method directly regards the maximum energy or dangerous value in the far-field microseismic events in the tunnel 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 tunnel limit equilibrium zone, resulting in an underestimation of the impact energy release.

[0135] Figure 8 FIG. 1 is a flow chart of a method for determining residual impulse energy provided by an embodiment of the present invention. Figure 8 As shown, the determination method may include the following steps S801-S804.

[0136] Before executing step S801, the determination method may also include: determining the radius of the crushing zone and the radius of the softening zone based on the system equation of the tunnel, the first equivalent ground stress, the disturbance response instability criterion, the damage variables of the coal rock in the elastic zone of the surrounding rock, the damage variables of the coal rock in the softening zone, and the damage variables of the coal rock in the crushing zone.

[0137] Specifically, according to the system equation of the roadway shown in equation (3), the first equivalent ground stress, the disturbance response instability criterion shown in equation (6), the damage variable D0 of the coal rock in the elastic zone, the damage variable D1 of the coal rock in the softening zone, and the damage variable D2 of the coal rock in the crushing zone listed from top to bottom as shown in equation (7), the radius ρ of the crushing zone can be determined. d and the softening zone radius ρ P .

[0138]

[0139]

[0140] Where ρ is the surrounding rock radius of the roadway (m); γ is an intermediate variable, γ = λ2 / E+(1-ξ)λ2 / λ1+ξ. Formula (6) can be obtained For example, for Figure 6 For the roadway corresponding to the I-type curve shown in the figure, the radius ρ of the crushing zone of the roadway surrounding rock under the action of the first equivalent ground stress P1 can be calculated. d =7.9m, softening zone radius ρ p =10.87m.

[0141] Alternatively, the above-mentioned radii (for example, the radius of the crushing zone and the radius of the softening zone) may be determined according to existing methods.

[0142] Step S801: Determine the total energy consumption of the resistance zone of the surrounding rock based on the damage variables of the coal rock in the softening zone and the damage variables of the coal rock in the crushing zone of the tunnel, the equivalent radius of the tunnel space, the crushing zone radius and the softening zone radius.

[0143] Wherein, the resistance zone includes a crushing zone and a softening zone.

[0144] Specifically, the damage variable D1 of the coal rock in the softening zone and the damage variable D2 of the coal rock in the crushing zone, the equivalent radius ρ0 of the tunnel space, the radius of the crushing zone ρ d and softening zone radius ρ p And the following formula (8) (i.e. the minimum energy principle of coal rock dynamic failure), determine the total energy consumption E of the resistance zone of the surrounding rock rock :

[0145]

[0146] Among them, σ c is the uniaxial compressive strength of coal rock; ξ is the residual strength coefficient; λ2 is the residual drop modulus; λ1 is the softening drop modulus of coal rock.

[0147] against Figure 6The roadway corresponding to the I-type curve shown in the figure (Example 1) can determine the total energy consumption E of the resistance zone of the surrounding rock. rock is 0.319856MJ / m; for Figure 7 The roadway corresponding to the type II curve shown (Example 2) can determine the total energy consumption E of the resistance zone of the surrounding rock. rock =4.11MJ / m.

[0148] This step can quantitatively estimate the spatial range of the surrounding rock resistance zone when the impact is initiated, thereby accurately estimating the surrounding rock dissipated energy, thereby greatly improving the stability of the tunnel.

[0149] Step S802, determining the kinetic energy generated by the impact of the resistance zone based on the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the radius of the softening zone, the equivalent radius of the tunnel space, and the average density of the coal rock in the resistance zone.

[0150] For step S802, determining the kinetic energy generated by the impact of the resistance zone may include: determining the impact movement speed of the coal rock in the resistance zone when the impact ground pressure occurs based on the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the softening zone radius and the equivalent radius of the tunnel space; determining the mass of the coal rock in the resistance zone based on the softening zone radius, the equivalent radius of the tunnel space and the average density of the coal rock in the resistance zone; and determining the kinetic energy generated by the impact of the resistance zone based on the impact movement speed and the mass of the coal rock in the resistance zone.

[0151] Specifically, find the most dangerous historical impact event (the maximum value of the equivalent impact event energy at the same epicenter distance) near the working face of the roadway to be designed, and record the most dangerous microseismic magnitude as ML max and the distance L0 from the most dangerous microseismic source to the destruction point of the tunnel.

[0152] Then, according to the radius of the softening zone and the equivalent radius of the roadway space, the thickness of the resistance zone L1 = ρ is determined. p -ρ0. And according to the following formula (9), the vibration peak velocity v′ of the surrounding rock mass at the outer boundary of the softening zone when the rock burst occurs is calculated:

[0153] lg[(L0-L1)v′]=3.95+0.57ML max , (9)

[0154] When the vibration peak velocity v' is obtained, the impact motion velocity of the coal rock in the resistance zone is v=2v'.

[0155] Then, according to the softening zone radius ρ p, the equivalent radius of the tunnel space ρ0, the average density of the coal rock in the resistance zone ρ c and Determine the mass M of coal rock in the resistance zone of the surrounding rock within the unit length of the tunnel.

[0156] Finally, according to the impact motion speed v, the mass M of the coal rock in the resistance zone and Determine the kinetic energy E generated by the impact of the resistance zone c .

[0157] In the first embodiment, the most dangerous far-field induced shock source energy E monitored by the microseismic monitoring system is used. max =1.7×10 7 J, the microseismic magnitude ML is obtained by converting the relationship between microseismic magnitude and energy max The distance from the most dangerous induced shock source to the limit equilibrium zone of the tunnel surrounding rock is L0-L1=30.84m, and the relationship lg[(L0-L1)v′]=3.95+0.57ML is used. max , the calculated result shows that when the induced impact energy reaches the limit equilibrium zone of the roadway, the peak vibration velocity of the surrounding rock particles at the outer boundary of the softening zone coal rock is v'≈1.15m / s. The impact motion velocity in the softening zone of the roadway is taken as v=2v'=2.3m / s; the density of the coal rock is taken as ρ c =1.35×10 3 kg / m 3 , then the coal and rock mass M in the resistance zone of the unit length roadway is: On this basis, we can obtain

[0158] In the second embodiment, the most dangerous far-field induced shock source energy E monitored by the microseismic monitoring system is used. max =7.7×10 7 J, the microseismic magnitude ML is obtained by converting the relationship between microseismic magnitude and energy max The distance from the most dangerous induced shock source to the ultimate equilibrium zone of the tunnel surrounding rock is L0-L1=32m, and the relationship lg[(L0-L1)v′]=3.95+0.57ML is used. max , the calculated result shows that when the induced impact energy reaches the ultimate equilibrium zone of the roadway, the peak vibration velocity of the surrounding rock particles at the outer boundary of the softening zone coal rock v'≈0.55m / s. The impact motion velocity in the softening zone of the roadway is taken as v=2v'=1.10m / s; the coal rock density ρ c 1.35×10 3 kg / m 3 , then the mass of coal and rock thrown from the resistance zone per unit length of the roadway is On this basis, the near-field coal and rock throwing energy caused by far-field dynamic load in unit length roadway can be obtained as:

[0159] Step S803: determining the stable state of the tunnel under the first equivalent in-situ stress.

[0160] The first equivalent ground stress is the force acting on the roadway A in the mining-affected zone in the roadway, such as Figure 4 Or P1 shown in 6.

[0161] For step S803, determining the stable state of the tunnel under the first equivalent in-situ stress (i.e., whether the tunnel has the possibility of instability under high static load conditions) may include: determining the surrounding rock-support mutual feedback equilibrium curve under the first equivalent in-situ stress based on the system equation of the tunnel, the functional relationship between the displacement of the surrounding rock of the tunnel and the radius of the crushing zone, and the functional relationship between the first equivalent in-situ stress and the boundary stress of the crushing zone to the softening zone under the first equivalent in-situ stress and the support strength required for the tunnel space and the radius of the crushing zone; and determining the stable state of the tunnel under the first equivalent in-situ stress in the following manner: determining that the tunnel is not in an unstable state under the first equivalent in-situ stress when there is no extreme point on the surrounding rock-support mutual feedback equilibrium curve; or determining that the tunnel is in an unstable state under the first equivalent in-situ stress when there is an extreme point on the surrounding rock-support mutual feedback equilibrium curve.

[0162] Among them, determining the surrounding rock-support mutual feedback balance curve under the first equivalent ground stress includes: determining the functional relationship between the first equivalent ground stress and the boundary stress according to the system equation of the tunnel; and determining the surrounding rock-support mutual feedback balance curve according to the functional relationship between the first equivalent ground stress and the boundary stress, the functional relationship between the boundary stress and the support strength and the crushing zone radius, and the functional relationship between the displacement of the surrounding rock of the tunnel and the crushing zone radius.

[0163] The above two processes can be seen in detail in the judgment of whether the extreme point S0 exists above.

[0164] Step S804, determining the residual impact energy that the hydraulic support to be selected needs to absorb based on the stable state of the tunnel 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 anchor support in the tunnel.

[0165] According to the stable state of the tunnel under high static load conditions, the following two cases are discussed.

[0166] Case 1 (Example 1): When the tunnel is not in an unstable state under the first equivalent ground stress, determining the residual impulse energy may include: subtracting the sum of the total energy consumption of the resistance zone and the energy consumption of the anchor support from the kinetic energy generated by the impact of the resistance zone to obtain the residual impulse energy.

[0167] First, we introduce the estimation of the energy consumption of anchor support (for example, the energy consumption of anchor support per meter in the tunnel E bolt-cable ) process.

[0168] For example, the anchor bolt specification used in the tunnel is φ20×2500mm threaded steel anchor bolt (according to the yield strength σ s ≥380MPa, elongation δ g ≥15%). The energy absorption capacity of anchor bolts can be calculated based on yield strength and elongation: the energy absorption capacity of a single anchor bolt E ubolt =πφ 2 σ s δl bolt / 4=31.32kJ, where l bolt It is the effective energy absorption length of the anchor rod (1750mm).

[0169] The anchor cable specification used in the tunnel is φ=18.9mm steel strand (according to the yield strength σ s ≥1820MPa, elongation δ s ≥5%), the length of the anchor cables supporting the top plate and the two sides is 10.50m. The energy absorption capacity of the anchor cable is calculated based on its yield strength and elongation. The energy absorption of a single anchor cable is E ucable =πφ 2 σ s δl cable / 4=186.29kJ, where l cable is the effective energy absorption length of the anchor cable.

[0170] On this basis, it can be estimated Where, N is the number of anchor rods in a row of the tunnel section, M is the number of anchor cables in a row; S cable is the anchor spacing, S cable is the anchor cable spacing; η bolt is the energy absorption efficiency of the anchor bolt, η cable is the energy absorption efficiency of the anchor cable,

[0171] For the case where the roadway has no possibility of instability under the first equivalent ground stress, only the far-field disturbance energy needs to be considered (i.e., for the roadway where the surrounding rock of the roadway does not have a dynamic instability extreme point under the first equivalent ground stress condition, only the impact energy of the far-field disturbance on the hydraulic support is regarded as the impact rock pressure failure energy). After the far-field disturbance energy dissipates energy in the resistance zone and the anchor body, the remaining impact energy E that needs to be absorbed by the hydraulic support is residual =E c -E bolt-cable -E rock =0.2845MJ / m.

[0172] Case 2 (Example 2): When the tunnel is in an unstable state under the first equivalent ground stress, determining the residual impulse energy may include: determining the released energy of the elastic zone based on the first equivalent ground stress, the vertical coordinate of the extreme point of the surrounding rock-support mutual feed equilibrium 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 residual impulse energy.

[0173] First, we introduce the method of estimating the energy consumption of anchor support (for example, the energy consumption of anchor support per meter of tunnel E bolt-cable ) process, the energy absorption of the O-shaped shed support can be ignored.

[0174] Through testing and calculation, it can be obtained that the energy absorption of a single traditional anchor is E ubolt , Single traditional anchor cable absorbs energy E ucable They are: E ubolt =2.08E+04J;E ucable =1.28E+05J. Through testing and calculation, it can be obtained that the energy absorbed by the reinforced constant resistance anchor cable used in the tunnel is E ucable-con =5.25E+04J.

[0175] On this basis, the energy consumption E of the anchor support per unit length of the tunnel can be calculated: bolt-cable for:

[0176]

[0177] Where N ubolt is the number of common anchor rods in a row in the tunnel section; M ucable and M ucable-con are the number of common anchor cables and constant resistance anchor cables in a row of tunnel sections; S bolt is the common anchor bolt spacing; S cable and S cable-con are the spacing of ordinary anchor cables and constant resistance anchor cables respectively. Based on the gradient characteristics of surrounding rock softening and crushing, the energy absorption efficiency of anchor rods and anchor cables is determined as follows:bolt is the energy absorption efficiency of ordinary anchor rods, η cable For the energy absorption efficiency of traditional anchor cables, and η cable-con is the energy absorption efficiency of the constant resistance anchor cable,

[0178] Then, according to the first equivalent ground stress P1, the vertical coordinate p of the extreme point S0 of the surrounding rock-support mutual feed equilibrium curve scr and the energy release rate η of the elastic zone of the surrounding rock, and determine the release energy E of the elastic zone cr :

[0179]

[0180] in, p scr =p sum , which is the total support strength of the support equipment in the tunnel (MPa); q is an intermediate variable, is the internal friction angle of the surrounding rock in the crushing area; η can be any value between 0.1% and 1%. When η = 1%, E cr =3.84×10 6 J / m.

[0181] In the case where the tunnel is likely to become unstable under the first equivalent ground stress, it is necessary to consider the superposition energy of the far-field disturbance energy and the elastic energy of the tunnel surrounding rock in the near field. After the superposition energy dissipates energy in the resistance zone and the anchor body, the residual impact energy E that needs to be absorbed by the hydraulic support is residual =E c +E cr -E bolt-cable -E rock =2.03×10 5 J / m. In other words, the energy absorption and impact prevention principle based on energy conservation determines the support parameters. The total energy absorbed by the energy-absorbing support is the impact energy of the far-field disturbance on the support and the elastic energy released in the near-field limit equilibrium zone of the tunnel surrounding rock.

[0182] An embodiment of the present invention further provides a method for selecting a hydraulic support. The method may include: determining the residual impulse energy required to be absorbed by the hydraulic support to be selected according to the residual impulse energy determination method; and determining the hydraulic support that matches the roadway based on the residual impulse energy required to be absorbed by the hydraulic support.

[0183] Among them, determining the hydraulic support that matches the tunnel may include: determining the absorption and displacement stroke required by the energy absorber of the hydraulic support and the energy required to be absorbed by a single support in the hydraulic support based on the residual impact energy that the hydraulic support needs to absorb; and selecting the model of the hydraulic support based on the absorption and displacement stroke required by the energy absorber and the energy required to be absorbed by the single support.

[0184] Specifically, for the two-column guide-rod-free unit type energy-absorbing and impact-resistant hydraulic support, according to the distance l0 (l0 = 2.4m) between any two adjacent hydraulic supports, the residual impact energy E that the hydraulic support needs to absorb residual (E residual =0.2845MJ / m) and the absorption and yield resistance of the hydraulic support (F n =6000kN), determine the hydraulic support's absorption and displacement stroke L str =l0E residual / F n =2.4m*0.2845MJ / m / 6000kN=113.80mm. According to the distance l0 between any two adjacent hydraulic supports (l0=2.4m) and the residual impact energy E that the hydraulic supports need to absorb residual (E residual =0.2845MJ / m), determine the required energy absorption of the hydraulic support as E support =0.2845MJ / m*2.4m=682.80kJ.

[0185] Due to the absorption and displacement stroke L of the hydraulic support str (L str =113.80mm) is less than the impact displacement L of the bracket imp (L imp =120mm) and the energy absorption required for a single bracket is E support (E support =682.80kJ) is less than the energy absorption E of a single bracket imp (E imp =720kJ), so the two-column guide rod-free unit type energy-absorbing and anti-impact hydraulic support can meet the energy-absorbing and anti-impact requirements of the current tunnel in terms of impact displacement and impact absorption energy.

[0186] Similarly, for the combination of the door-type energy-absorbing and anti-impact hydraulic support and the stack-type energy-absorbing support (i.e., support combination), according to the distance l0 (l0 = 5m) between any two adjacent hydraulic supports, the residual impact energy E that the hydraulic support needs to absorb residual (E residual =2.03×10 5 J / m) and the absorption and yield resistance of the hydraulic support (F w-static=10600kN), determine the hydraulic support's absorption and displacement stroke L str =l0E residual / 1.3F w-static =73.66mm. According to the distance l0 between any two adjacent hydraulic supports (l0 = 5m) and the residual impact energy E that the hydraulic supports need to absorb residual (E residual =2.03×10 5 J / m), determine the required energy absorption of the hydraulic support as E support =2.03×10 5 J / m*5m=1.02MJ.

[0187] Due to the absorption and displacement stroke L of the hydraulic support str (L str =73.66mm) is less than the impact displacement L of the bracket imp (L imp =120mm) and the energy absorption required for a single bracket is E support (E support =1.02MJ) is less than the energy absorption E of a single bracket imp (E imp =1.66MJ), so the support combination can meet the energy absorption and impact prevention requirements of the current tunnel in terms of impact displacement and impact absorption energy, and the impact prevention safety factor N can be obtained. e =E imp / E support =1.63.

[0188] The selection method may also include: determining the extension amount of the active column in the column according to the model of the selected hydraulic support and the height of the tunnel; determining the stiffness of the selected hydraulic support according to the extension amount of the active column in the column; and determining the timing of initial support according to the initial support force and working resistance of the selected hydraulic support and the support balance point of the surrounding rock-support mutual feedback balance curve under the stiffness and the second equivalent ground stress, wherein the second equivalent ground stress is the equivalent ground stress suffered by the tunnel in the non-mining influence area.

[0189] The selection method may further include: determining the support balance point of the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress and the support balance point of the surrounding rock-support mutual feeding balance curve under the second equivalent ground stress. Correspondingly, the determination of the support balance point of the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress includes: when the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress does not have an extreme point, using the surrounding rock separation control condition to determine the support balance point of the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress; or when the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress has an extreme point, determining the support balance point of the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress. The extreme point of the support mutual feed balance curve is the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress. The determination of the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress includes: determining the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress according to the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress and the surrounding rock-support mutual feed balance curve under the second equivalent ground stress, wherein the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress is equal to the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress.

[0190] For details on the specific process, please refer to the description of determining the timing of the initial support above.

[0191] An embodiment of the present invention further provides a system for determining residual impulse energy. The determination system may include: an energy consumption determination device for determining the total energy consumption of the resistance zone of the surrounding rock according to the damage variables of the coal rock in the softening zone and the damage variables of the coal rock in the crushing zone of the surrounding rock of the tunnel, the equivalent radius of the tunnel space, the radius of the crushing zone and the radius of the softening zone, wherein the resistance zone includes the crushing zone and the softening zone; a kinetic energy determination 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 destruction point of the tunnel, the radius of the softening zone, the equivalent radius of the tunnel space and the average density of the coal rock in the resistance zone; and a state determination device for determining the stable state of the tunnel under the first equivalent ground stress, wherein the first equivalent ground stress is the equivalent ground stress to which the tunnel in the mining influence zone is subjected; and a residual impulse energy determination device for determining the residual impulse energy required to be absorbed by the hydraulic support to be selected according to the stable state of the tunnel 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 anchor support in the tunnel.

[0192] The specific details and benefits of the system for determining residual impulse energy provided by the present invention can be found in the above description of the method for determining residual impulse energy, which will not be repeated here.

[0193] One embodiment of the present invention further provides a hydraulic support selection system. The selection system may include: a residual impulse energy determination system for determining the residual impulse energy required to be absorbed by the hydraulic support to be selected; and a support determination device for determining the hydraulic support that matches the roadway based on the residual impulse energy required to be absorbed by the hydraulic support.

[0194] The specific details and benefits of the hydraulic support selection system provided by the present invention can be found in the description of the hydraulic support selection method described above, and will not be repeated here.

[0195] To sum up, the present invention creatively determines the total energy consumption of the resistance zone of the surrounding rock based on the damage variables of the coal rock in the softening zone and the damage variables of the coal rock in the crushing zone of the surrounding rock of the tunnel, the equivalent radius of the tunnel space, the radius of the crushing zone and the radius of the softening zone; determines the kinetic energy generated by the impact of the resistance zone based on the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the radius of the softening zone, the equivalent radius of the tunnel space and the average density of the coal rock in the resistance zone; determines the stable state of the tunnel under the first equivalent ground stress; and then determines the residual impact energy that the hydraulic support to be selected needs to absorb based on the stable state of the tunnel 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 anchoring support in the tunnel. By considering the superposition process of "disturbance energy released in the far field of the tunnel" and "energy released in the near field of the tunnel" when tunnel impact ground pressure occurs, the present invention can quantitatively determine the residual impact energy that the hydraulic support to be selected needs to absorb, and then realize the parametric selection of tunnel anti-impact hydraulic support based on the residual impact energy.

[0196] The above describes how to determine the relevant characteristic parameters of hydraulic supports (for example, the support strength of the hydraulic supports for the surrounding rock, or the residual impact energy that the hydraulic supports need to absorb, etc.) from the two aspects of "prevention" (selecting the hydraulic supports based on the support strength before the impact is initiated) and "treatment" (selecting the hydraulic supports based on the residual impact energy after the impact is initiated). In fact, it is also possible to combine the two aspects of "prevention" and "treatment" to first determine the support strength of the hydraulic supports for the surrounding rock and the residual impact energy that the hydraulic supports need to absorb, and then determine the hydraulic supports that match the roadway based on the determined support strength and residual impact energy.

[0197] An embodiment of the present invention also provides a method for selecting a hydraulic support. Figure 9 As shown, the selection method may include the following steps S901-S905.

[0198] Step S901: determining the second equivalent in-situ stress of the roadway in the non-mining influence area and the first equivalent in-situ stress of the roadway in the mining influence area.

[0199] Step S902: Determine a first surrounding rock-support mutual-feed balance curve under the first equivalent in-situ stress and a second surrounding rock-support mutual-feed balance curve under the second equivalent in-situ stress based on the system equation of the tunnel, the functional relationship between the displacement of the surrounding rock of the tunnel and the radius of the crushing zone, the second equivalent in-situ stress, the first equivalent in-situ stress, the functional relationship between the first boundary stress of the crushing zone to the softening zone under the first equivalent in-situ stress and the first support strength required for the tunnel space and the radius of the crushing zone, and the functional relationship between the second boundary stress of the crushing zone to the softening zone under the second equivalent in-situ stress and the second support strength required for the tunnel space and the radius of the crushing zone.

[0200] Step S903: Determine the support strength of the hydraulic support to be selected for the surrounding rock and the minimum expansion and contraction required for the active column in the column of the hydraulic support based on the first surrounding rock-support mutual feed balance curve, the second surrounding rock-support mutual feed balance curve and the stress of the anchor support of the tunnel.

[0201] Step S904, based on the damage variables of the coal rock in the softening zone of the surrounding rock and the damage variables of the coal rock in the crushing zone, the radius of the crushing zone, the radius of the softening zone, the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the equivalent radius of the tunnel space and the energy consumption of the anchor support, determine the residual impact energy that the hydraulic support needs to absorb.

[0202] Step S905 , determining the hydraulic support that matches the tunnel according to the support strength of the hydraulic support for the surrounding rock, the residual impact energy that the hydraulic support needs to absorb, and the minimum expansion and contraction amount required by the active column in the column.

[0203] The above embodiment, based on further consideration of the coordinated deformation and mutual feedback response of the "surrounding rock-support" system, invents a design and selection method for an energy-absorbing hydraulic support from the two aspects of strength design (anti-impact / "prevention") and energy design (impact control / "treatment"), to ensure that the anti-impact support equipment operates scientifically with a reasonable safety factor.

[0204] For the specific process of determining the support strength, the residual impact energy and the minimum expansion and contraction amount, please refer to the relevant description in the above "prevention" or "treatment" plan.

[0205] Among them, the determination of the hydraulic support that matches the tunnel may include: determining the static load working load and absorption and displacement resistance required for the hydraulic support to prevent impact based on the support strength of the hydraulic support for the surrounding rock; determining the absorption and displacement 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 based on the residual impact energy that the hydraulic support needs to absorb; and selecting the model of the hydraulic support based on the static load working load and absorption and displacement resistance required for the hydraulic support to prevent impact, the absorption and displacement stroke required for the energy absorber and the energy required to be absorbed by the single support, and the minimum expansion and contraction amount required for the active column in the column.

[0206] The specific process for determining the static working load, the absorption and yielding resistance, the absorption and yielding stroke, the required absorbed energy, and the minimum expansion and contraction amount can be found in the relevant descriptions of the "Prevention" or "Cure" solutions above. Then, combining the above-determined five parameters and the corresponding criteria, the model of the hydraulic support can be comprehensively selected.

[0207] Therefore, it can be determined that the two-column guide rod-free unit energy-absorbing and anti-impact hydraulic support (or a combination of portal and stacking supports) fully meets the current tunnel anti-impact / anti-impact response requirements for energy-absorbing supports in terms of strength and energy in terms of working resistance to impact displacement, impact displacement displacement, impact absorption energy, static load and active column pressure relief stroke.

[0208] After completing the applicability judgment of multiple or all brackets, if multiple models meet the requirements, the selection can be further optimized in terms of ground pressure ratio, bracket anti-tilt, etc.; if the calculated energy absorption parameter design cannot match the existing bracket model database, resulting in the inability to complete the bracket selection, new parameter design of the bracket needs to be implemented.

[0209] After strengthening the coal seam area or local decompression work, re-evaluate the first equivalent ground stress P2 under the influence of the mining face, and perform other related steps to realize cyclic calculation until all strength parameters and energy absorption parameters are reasonably determined or the support is customized to meet the working conditions to be designed. The exit criteria for cyclic 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 required for the support to prevent impact; the absorption and yield resistance of the existing support is greater than or equal to the absorption and yield resistance required for the support to prevent impact; the pressure relief stroke (i.e., the maximum extension length) of the active column of the existing support is greater than the minimum extension required by the active column in the column; the impact yield displacement of the existing support is greater than or equal to the absorption and yield displacement of the support; the impact absorption energy of the existing support is greater than the required energy absorption of the support.

[0210] In summary, the present invention creatively determines the second equivalent geostress of the roadway in the non-mining influence zone and the first equivalent geostress of the roadway in the mining influence zone; 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 crushing zone, the second equivalent geostress, the first equivalent geostress, the functional relationship between the first boundary stress of the crushing zone to the softening zone under the first equivalent geostress and the first support strength required for the roadway space and the radius of the crushing zone, and the functional relationship between the second boundary stress of the crushing zone to the softening zone under the second equivalent geostress and the second support strength required for the roadway space and the radius of the crushing zone, the first surrounding rock-support mutual feed balance curve under the first equivalent geostress and the second surrounding rock-support mutual feed balance curve under the second equivalent geostress are determined; according to the first The surrounding rock-support mutual feed balance curve, the second surrounding rock-support mutual feed balance curve and the stress of the anchor support of the tunnel are used to determine the support strength of the hydraulic support to be selected for the surrounding rock and the minimum expansion and contraction required by the active column in the column of the hydraulic support; according to the damage variables of the coal rock in the softening zone of the surrounding rock and the damage variables of the coal rock in the crushing zone, the radius of the crushing zone, the radius of the softening zone, the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the equivalent radius of the tunnel space and the energy consumption of the anchor support, the residual impact energy required to be absorbed by the hydraulic support is determined; and according to the support strength of the hydraulic support for the surrounding rock, the residual impact energy required to be absorbed by the hydraulic support and the minimum expansion and contraction required by the active column in the column, the hydraulic support matching the tunnel is determined. Therefore, on the one hand, the present invention takes into account the loading effect of the mining of the working face on the advance tunnel, and can quantitatively determine the deformation coordination response and mutual feedback balance relationship of the "surrounding rock and support" in the rock burst tunnel; on the other hand, it also takes into account the superposition process of "disturbance energy released in the far field of the tunnel" and "energy released in the near field of the tunnel" when rock burst occurs in the tunnel, and can quantitatively determine the residual impact energy that the hydraulic support to be selected needs to absorb. Therefore, the support strength and residual impact energy of the hydraulic support to be selected for the surrounding rock can be accurately determined, and then the parametric selection of the tunnel anti-impact hydraulic support can be realized at least based on the support strength and the residual impact energy.

[0211] One embodiment of the present invention also provides a hydraulic support selection system. The selection system may include: a stress determination device for determining the second equivalent ground stress of the roadway in the non-mining influence zone and the first equivalent ground stress of the roadway in the mining influence zone; a balance curve determination device for determining the first surrounding rock-support mutual feed balance curve under the first equivalent ground stress and the second surrounding rock-support mutual feed balance curve under the second 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 crushing zone, the second equivalent ground stress, the first equivalent ground stress, the functional relationship between the first boundary stress of the crushing zone to the softening zone under the first equivalent ground stress and the first support strength required for the roadway space and the radius of the crushing zone, and the functional relationship between the second boundary stress of the crushing zone to the softening zone under the second equivalent ground stress and the second support strength required for the roadway space and the radius of the crushing zone; an expansion amount determination device for determining the first surrounding rock-support mutual feed balance curve under the first equivalent ground stress and the second surrounding rock-support mutual feed balance curve under the second 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 crushing zone, the second equivalent ground stress, the first equivalent ground stress, the functional relationship between the first boundary stress of the crushing zone to the softening zone under the first ... The first surrounding rock-support mutual feed balance curve, the second surrounding rock-support mutual feed balance curve and the stress of the anchor support of the tunnel are used to determine the support strength of the hydraulic support to be selected for the surrounding rock and the minimum expansion and contraction required by the active column in the column of the hydraulic support; a residual impulse energy determination device is used to determine the residual impulse energy that the hydraulic support needs to absorb based on the damage variables of the coal rock in the softening zone of the surrounding rock and the damage variables of the coal rock in the crushing zone, the radius of the crushing zone, the radius of the softening zone, the most dangerous microseismic magnitude, the distance from the most dangerous microseismic source to the destruction point of the tunnel, the equivalent radius of the tunnel space and the energy consumption of the anchor support; and a hydraulic support determination device is used to determine the hydraulic support that matches the tunnel based on the support strength of the hydraulic support for the surrounding rock, the residual impulse energy that the hydraulic support needs to absorb and the minimum expansion and contraction required by the active column in the column.

[0212] The specific details and benefits of the hydraulic support selection system provided by the present invention can be found in the description of the hydraulic support selection method described above, and will not be repeated here.

[0213] An embodiment of the present invention further provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, the method for selecting a hydraulic support is implemented.

[0214] It should be noted that the steps executed by the selection system or the various devices in the determination system can be executed by a processor.

[0215] The beneficial effects of the above embodiments of the present invention include at least the following three aspects:

[0216] First, a method for selecting hydraulic supports for rock burst prevention and energy absorption in rock burst tunnels is provided. This method is based on the quantitative theory of rock burst occurrence in tunnels and the theoretical calculation formula for its critical conditions. It clarifies the physical process of static and dynamic stresses and energy superposition of the near-field and far-field surrounding rocks when rock burst occurs in tunnels, laying a solid cognitive foundation for the physical process of rock burst for the selection of anti-rock burst supports.

[0217] Second, a combination of analytical calculation and engineering statistics was considered to achieve quantitative estimation of the "disturbance energy released in the far field of the tunnel" and the "energy released in the near field of the tunnel." This provided a comprehensive feasibility and applicability criterion for the design of energy-absorbing anti-collision supports, as well as their design methods. This provided a scientific mathematical calculation method and basis for the selection of anti-collision supports.

[0218] Third, the coordinated response relationship of the mutual feedback equilibrium deformation of the "surrounding rock and support" in the impact ground pressure tunnel is fully considered, which will effectively guide the parametric selection of support equipment based on stability, such as energy absorption resistance, yield stroke, support stiffness, initial support force and other parameters.

[0219] The above describes in detail the optional implementation methods of the embodiments of the present invention in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation methods. Within the technical concept 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 scope of protection of the embodiments of the present invention.

[0220] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0221] Those skilled in the art will understand that all or part of the steps in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a program, which is stored in a storage medium and includes a number of instructions for causing a single-chip microcomputer, chip or processor to execute all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program code.

[0222] In addition, various implementations of the embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A method for determining residual impulse energy, characterized in that: The determination method includes: Determine the total energy consumption of the resistance zone of the surrounding rock based on the damage variables of the coal rock in the softening zone and the damage variables of the coal rock in the crushing zone of the surrounding rock of the roadway, the equivalent radius of the roadway space, the radius of the crushing zone, and the radius of the softening zone, wherein the resistance zone includes the crushing zone and the softening zone; Determine the kinetic energy generated by the impact of the resistance zone based on 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; Determining a stable state of the tunnel under a first equivalent in-situ stress, wherein the first equivalent in-situ stress is the equivalent in-situ stress experienced by the tunnel in the mining-affected zone; and The residual impact energy required to be absorbed by the hydraulic support to be selected is determined based on 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 anchor support in the roadway. Determining the stable state of the roadway under the first equivalent in-situ stress comprises: Determine a surrounding rock-support mutual feedback equilibrium curve under the first equivalent in-situ stress based on the system equation of the tunnel, the functional relationship between the displacement of the surrounding rock of the tunnel and the radius of the crushing zone, the first equivalent in-situ stress, the boundary stress of the crushing zone to the softening zone under the first equivalent in-situ stress, the support strength required for the tunnel space, and the radius of the crushing zone; and The stable state of the tunnel under the first equivalent in-situ stress is determined by: In the case where the surrounding rock-support mutual feedback equilibrium curve under the first equivalent in-situ stress does not have an extreme value point, determining that the tunnel does not exist in an unstable state under the first equivalent in-situ stress; or When there is an extreme point in the surrounding rock-support mutual feeding equilibrium curve under the first equivalent ground stress, it is determined that the tunnel is in an unstable state under the first equivalent ground stress.

2. The determination method according to claim 1, characterized in that When the tunnel is not in an unstable state under the first equivalent ground stress, determining the residual impulse energy includes: The residual impact energy is obtained by subtracting the sum of the total energy consumption of the resistance zone and the energy consumption of the anchor support from the kinetic energy generated by the impact of the resistance zone.

3. The determination method according to claim 1, characterized in that When the tunnel is in an unstable state under the first equivalent ground stress, determining the residual impulse energy includes: Determining the released energy of the elastic zone according to the first equivalent ground stress, the ordinate of the extreme point of the surrounding rock-support mutual feedback equilibrium curve, and the energy release rate of the elastic zone of the surrounding rock; and The residual impact energy is obtained by 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.

4. The determination method according to claim 1, characterized in that Determining the surrounding rock-support mutual feedback equilibrium curve under the first equivalent ground stress includes: determining a functional relationship between the first equivalent in-situ stress and the boundary stress according to a system equation of the roadway; and The surrounding rock-support mutual feed balance curve is determined based on the functional relationship between the first equivalent ground stress and the boundary stress, the functional relationship between the boundary stress and the support strength and the crushing zone radius, and the functional relationship between the displacement of the surrounding rock of the tunnel and the crushing zone radius.

5. The determination method according to claim 1, characterized in that: Determining the kinetic energy generated by the impact of the resistance zone includes: Determining the impact movement velocity of the coal rock in the resistance zone when rock burst occurs based on 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, and the equivalent radius of the roadway space; Determining the mass of the coal rock in the resistance zone according to the radius of the softening zone, the equivalent radius of the roadway space, and the average density of the coal rock in the resistance zone; and The kinetic energy generated by the impact in the resistance zone is determined according to the impact motion speed and the mass of the coal rock in the resistance zone.

6. The determination method according to claim 1, characterized in that: The determination method further includes: The radius of the crushing zone and the radius of the softening zone are determined based on the system equation of the tunnel, the first equivalent ground stress, the disturbance response instability criterion, the damage variables of the coal rock in the elastic zone of the surrounding rock, the damage variables of the coal rock in the softening zone, and the damage variables of the coal rock in the crushing zone.

7. A method for selecting a hydraulic support, characterized in that: The selection method includes: The method for determining residual impulse energy according to any one of claims 1 to 6, determining the residual impulse energy required to be absorbed by the hydraulic support to be selected; and The hydraulic support that matches the roadway is determined based on the residual impact energy that the hydraulic support needs to absorb.

8. The selection method according to claim 7, characterized in that: Determining the hydraulic support that matches the roadway includes: Determining the required absorbing and yielding stroke of the energy absorber of the hydraulic support and the energy required to be absorbed by a single support of the hydraulic support according to the residual impact energy required to be absorbed by the hydraulic support; and The model of the hydraulic support is selected according to the required absorption and displacement stroke of the energy absorber and the energy required to be absorbed by the single support.

9. The selection method according to claim 8, characterized in that: The selection method further includes: Determine the extension of the plunger in the column according to the selected hydraulic support model and the height of the roadway; Determining the stiffness of the selected hydraulic support according to the extension of the plunger in the column; and The timing of initial support is determined based on the initial support force, working resistance and stiffness of the selected hydraulic support and the support balance point of the surrounding rock-support mutual feedback balance curve under the second equivalent ground stress, wherein the second equivalent ground stress is the equivalent ground stress exerted on the tunnel in the non-mining influence area.

10. The selection method according to claim 9, characterized in that: In the case where the residual impulse energy required to be absorbed by the hydraulic support to be selected is determined by the residual impulse energy determination method according to claim 1, the selection method further comprises: determining a support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress and a support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress, Accordingly, determining the support balance point of the surrounding rock-support mutual feedback balance curve under the first equivalent ground stress includes: In the case where the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress does not have an extreme point, determining the support balance point of the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress by using the surrounding rock separation control condition; or In the case where the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress has an extreme point, the extreme point of the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress is determined as the support balance point of the surrounding rock-support mutual feeding balance curve under the first equivalent ground stress. The method of determining the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress includes: determining the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress according to the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress and the surrounding rock-support mutual feed balance curve under the second equivalent ground stress, wherein the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the first equivalent ground stress is equal to the vertical coordinate of the support balance point of the surrounding rock-support mutual feed balance curve under the second equivalent ground stress.

11. A system for determining residual impulse energy, characterized in that: The determination system comprises: an energy consumption determination device for determining the total energy consumption of the resistance zone of the surrounding rock according to the damage variables of the coal rock in the softening zone and the damage variables of the coal rock in the crushing zone of the surrounding rock of the roadway, the equivalent radius of the roadway space, the radius of the crushing zone, and the radius of the softening zone, wherein the resistance zone includes the crushing zone and the softening zone; a kinetic energy determination device for determining the kinetic energy generated by the impact of the resistance zone based on 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; and a state determining device, configured to determine a stable state of the roadway under a first equivalent ground stress, wherein the first equivalent ground stress is the equivalent ground stress to which the roadway in the mining-affected zone is subjected; and The residual energy determination device is used to determine the residual energy that needs to be absorbed by the hydraulic support to be selected based on the stable state of the tunnel 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 anchor support in the tunnel. Determining the stable state of the roadway under the first equivalent in-situ stress comprises: Determine a surrounding rock-support mutual feedback equilibrium curve under the first equivalent in-situ stress based on the system equation of the tunnel, the functional relationship between the displacement of the surrounding rock of the tunnel and the radius of the crushing zone, the first equivalent in-situ stress, the boundary stress of the crushing zone to the softening zone under the first equivalent in-situ stress, the support strength required for the tunnel space, and the radius of the crushing zone; and The stable state of the tunnel under the first equivalent in-situ stress is determined by: In the case where the surrounding rock-support mutual feedback equilibrium curve under the first equivalent in-situ stress does not have an extreme value point, determining that the tunnel does not exist in an unstable state under the first equivalent in-situ stress; or When there is an extreme point in the surrounding rock-support mutual feeding equilibrium curve under the first equivalent ground stress, it is determined that the tunnel is in an unstable state under the first equivalent ground stress.

12. A hydraulic support selection system, characterized in that: The selection system includes: The residual impulse energy determination system according to claim 11 is used to determine the residual impulse energy required to be absorbed by the hydraulic support to be selected; and The support determining device is used to determine the hydraulic support that matches the roadway according to the residual impact energy that the hydraulic support needs to absorb.

Images