Evaluation method for impact resistance of anchor-net cable support system in coal roadway of rock burst mine

Abstract

The present invention records a method for evaluating the impact resistance of the anchor-net cable support system of the coal roadway in a rock burst mine. Through field investigation of the engineering geological condition parameters and anchor-net cable support system parameters of the coal seam roadway in the rock burst mine, an experimental model is built according to the similarity theory, and a compensation load of a set value is applied to the top of the experimental model, and lateral constraints are applied to the experimental model to simulate the formation load on the surrounding rock in the roadway engineering prototype. Experimental support materials are made, and after the experimental model is maintained to meet the experimental requirements, the experimental roadway is excavated, and the experimental support materials are used to complete the roadway support. Microseismic detectors and stress gauges are set in the experimental model, and the acquired monitoring data is transmitted to a computer. A disturbance device is set at the same position of a group of experimental models to simulate impact disturbances, and the experimental models are observed respectively, and the data of the instability experimental model are collected to calculate the ultimate impact energy value that the anchor-net cable support system in the roadway engineering prototype can withstand.

Description

Technical Field

[0001] The invention relates to the field of anti-impact testing of tunnel support systems, and in particular to an anti-impact capability evaluation method for an anchor-net-cable support system of a coal tunnel in a rock burst mine. Background Art

[0002] With the increasing consumption of shallow coal resources in my country, the depth of coal mining is extending to the depth at a rate of 8 to 12 m / a. The geological environment of deep coal resources is extremely complex. During the mining process, deep well tunnels will inevitably be affected by impact dynamic loads, and the tunnel deformation is relatively strong, posing a great threat to the personnel and production safety of the mine. Regarding the mechanism of tunnel rock pressure, it is generally believed that the energy accumulated in the tunnel surrounding rock exceeds the energy consumed when the surrounding rock itself and the support structure are destroyed. The remaining energy is released in the form of kinetic energy, and at the same time causes great damage to the mine tunnel. Therefore, it is particularly important to more accurately evaluate the impact resistance of the tunnel support system.

[0003] Anchor-net cable support system has been widely used in coal mine support projects and has achieved certain results. However, how to accurately evaluate the impact resistance of anchor-net cable support system remains a difficult problem. At present, among the methods for evaluating the impact resistance of tunnel support systems, "A Calculation Method for the Impact Resistance of Tunnel Roof Anchor Support", with application publication number CN111259542A, records the theoretical calculation of the impact resistance of the tunnel roof anchor mesh support system, which mainly considers the bearing effect of the anchor mesh support system on kinetic energy and potential energy under ideal conditions, but the factors considered by this method are relatively limited; "A Precise Calculation Method for the Impact Resistance of Coal Mine Tunnel", with application publication number CN113586144A, is more accurate in the calculation method of the impact resistance of the support system, mainly considering the loading data obtained in the laboratory as the basis for calculation, but ignoring the impact of on-site construction on the support system, and not considering the interaction between the support system and the surrounding rock. The impact bearing capacity of the support system has not been fully exerted, and the method is relatively ideal, but does not consider the complex conditions during on-site destruction, and the results obtained are quite different from the actual situation.

[0004] In fact, the impact resistance of the tunnel anchor mesh cable support system is the result of the synergistic effect of the support structure and the tunnel surrounding rock. The above method directly calculates the total energy that the support system can bear based on the energy that the support material can withstand. It has the following shortcomings: (1) The evaluation and calculation of the impact resistance of the tunnel support system is carried out under relatively ideal conditions, which cannot directly reflect the strength of the support system, and thus cannot accurately measure the ultimate impact resistance energy that the support system can withstand; (2) The interaction between the support system and the surrounding rock is ignored, and the on-site construction conditions and the anchoring effect of the anchor mesh cable have certain deviations from the ideal state are not considered. The energy that the tunnel surrounding rock can absorb by its own deformation is also not considered; (3) The calculation formula is cumbersome and complicated, and the result is not intuitive enough. It is impossible to achieve a direct and accurate evaluation of the impact resistance of the tunnel support system, which greatly reduces the accuracy of the evaluation results. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a method for evaluating the impact resistance of an anchor mesh cable support system in a coal tunnel of a rock burst mine.

[0006] The technical solution of the present invention is:

[0007] A method for evaluating the impact resistance of an anchor-net-cable support system in a coal roadway of a rock burst mine comprises the following steps:

[0008] S1: Conduct field research on rock burst mines to obtain the engineering geological condition parameters and anchor-net cable support system parameters of the tunnel engineering prototype;

[0009] S2, build an experimental model based on similarity theory and the engineering geological condition parameters, where:

[0010] Setting the geometric similarity ratio of the experimental model to the tunnel engineering prototype, the similarity ratio of the bulk density of each rock layer, and the similarity ratio of the unidirectional compressive strength of each rock layer; setting the number and distribution of rock layers, the position of the key layer of the tunnel, and the occurrence of rock layers on the top and bottom plates of the tunnel in the experimental model to be the same or approximately the same as those of the tunnel engineering prototype;

[0011] S3, applying a compensation load of a set value to the top of the experimental model, and applying lateral constraints to the experimental model, so as to simulate the formation load on the surrounding rock of the tunnel in the tunnel engineering prototype;

[0012] S4, according to the similarity theory, based on the anchor net cable support system parameters described in step S1, and the geometric similarity ratio, strength similarity ratio and basic mechanical parameter test described in step S2, prepare the experimental support material for the experimental model;

[0013] S5, after the experimental model has been cured to meet the experimental requirements, excavating an experimental tunnel in the experimental model according to the geometric similarity ratio, and using the experimental support material in the experimental tunnel to complete tunnel support;

[0014] S6, setting a microseismic geophone and a strain gauge in the experimental model, wherein the microseismic geophone and the strain gauge are connected to a computer to transmit the acquired monitoring data to the computer;

[0015] S7, setting disturbance boreholes in sequence at the same positions of the N experimental models, and setting disturbance sources in the disturbance boreholes respectively, wherein the disturbance sources are used to provide disturbance energy to the experimental models in which they are located; observing the N experimental models respectively, and collecting the data transmitted by the microseismic detectors and stress gauges in the unstable experimental models, and calculating the ultimate impact energy value that the anchor mesh cable support system in the tunnel engineering prototype can withstand.

[0016] Furthermore, a compensation load is uniformly applied to the top of the experimental model, and the numerical calculation formula of the compensation load is:

[0017] F=σ 顶 s

[0018]

[0019] Where s is the area where the compensating load is applied; γ pi h is the bulk density of each rock layer surrounding the tunnel; i is the thickness of each rock layer; C σ is the similarity ratio of the uniaxial compressive strength of each rock layer in the experimental model.

[0020] Furthermore, the experimental requirements are: ambient temperature is 20±3°C, humidity is ≧50%, and curing time is ≧7 days.

[0021] Furthermore, the experimental support material is determined based on a pull-out test, a destructive test and a strength similarity relationship of the materials.

[0022] Furthermore, the microseismic geophone and the stress gauge are arranged at the anchor bolts in the experimental support material.

[0023] Furthermore, the gap between the anchor bolt and the wall of the anchor hole is filled with bonding material.

[0024] Furthermore, during the installation of the probe of the microseismic geophone, the deviation of the anchor bolt is less than 10°, and its exposed length is set to 30 mm.

[0025] Furthermore, the microseismic geophone is preferably arranged at the lower left corner of the tunnel of the experimental model and at the upper roof anchor.

[0026] Further, step S7 includes the following sub-steps:

[0027] S71, setting the numbers of N experimental models to 1 to N;

[0028] S72, the disturbance source is set to TNT explosives, and TNT explosives are added to 1 to N disturbance boreholes of the experimental model in sequence;

[0029] S73, fix the detonator and the detonating cord together and install them into the blast hole reserved in the experimental model, seal the hole, and use the detonator to detonate to simulate the effect of the impact disturbance dynamic load on the experimental tunnel;

[0030] S74, observe the damage of the experimental models group by group, and determine whether the anchor net cable support system has suffered impact damage or instability, and record the impact energy monitoring values ​​transmitted by the microseismic detector and stress gauge.

[0031] Furthermore, the amount of TNT explosive added is selected based on engineering analogy and experimental experience; the criterion for judging the instability of the anchor-net cable support system is that the collapsed area of ​​the roof of the experimental tunnel is ≧50% of the original area of ​​the roof.

[0032] Furthermore, the energy value collected by the microseismic geophone in the instability experimental model and the limit stress value collected by the strain gauge are collected according to the energy similarity ratio C E =C σ / 10, and the ultimate impact energy value that the anchor-net-cable support system in the tunnel engineering prototype can withstand is calculated.

[0033] Furthermore, during the construction of the experimental model, the construction materials used in the experimental model are similar to the materials of the tunnel engineering prototype; the consumption of the construction materials is calculated as follows:

[0034]

[0035] Where: Q is the total material consumption of the experimental model, kg; k is the loss coefficient of the material due to paving and other reasons; ρ is the density of the material used for paving the experimental model, kg / m 3 ; l m —Experimental model direction size, m; b m —Longitudinal dimension of the experimental model, m; m i —Thickness of the i-th rock layer in the experimental model, m, assuming that a total of n layers are laid.

[0036] The beneficial effects of the present invention are:

[0037] (1) The method described in the present invention can restore the on-site conditions of the rock burst mine, simulate the rock burst, collect key monitoring data, and comprehensively evaluate the safety of the support system. It can be applied to rock burst mines with complex geological conditions, multiple factors, and which cannot be calculated by traditional formulas. It can accurately evaluate the impact resistance of the anchor net cable support system in actual application.

[0038] (2) The method described in the present invention can be tested in the laboratory to reduce the interference of field tests on production. It also takes into account the interaction of multiple factors while ensuring the repeatability of the test, thereby improving the accuracy and scientificity of the evaluation results. It is an accurate and intuitive method for evaluating the impact resistance of the support system, which can help coal enterprises better understand and master the safety of the support system, and provide strong support for improving mine production efficiency and personnel safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 : Schematic diagram of the experimental model structure;

[0040] Figure 2 : Schematic diagram of the microseismic geophone installation structure. DETAILED DESCRIPTION

[0041] The present invention is described in detail below by way of embodiments in conjunction with the accompanying drawings.

[0042] The present invention describes a method for evaluating the impact resistance of an anchor-net cable support system in a coal tunnel of a rock burst mine, the method comprising the following steps:

[0043] S1, conduct field investigation on rock burst mine tunnels that have been equipped with anchor-net cable support systems to obtain the engineering geological condition parameters and anchor-net cable support system parameters of the tunnel engineering prototype.

[0044] in,

[0045] a. Engineering geological condition parameters include but are not limited to:

[0046] The width b and height h of the lane a , burial depth h b ;

[0047] Vertical stress of the stratum where the tunnel is located σ h ;

[0048] The number and distribution of rock layers surrounding the tunnel;

[0049] Bulk density of each rock layer surrounding the tunnel γ pi ;

[0050] Uniaxial compressive strength of each rock layer surrounding the tunnel σ pi ;

[0051] Location of key layers in the roadway;

[0052] The occurrence of rock strata on the roof and floor of the tunnel.

[0053] The engineering geological condition parameters of the above-mentioned tunnel are obtained by the measurement method commonly used in the field of coal tunnel mining, wherein the following method is preferably used for measurement and acquisition in this embodiment:

[0054] The width b and height h of the lane a The tunnel depth h is obtained by measuring with a tape measure. b Elevation measurement through vertical shaft introduction and underground elevation control measurement;

[0055] Vertical stress of the stratum where the tunnel is located h i is the thickness of each rock layer;

[0056] Tunnel surrounding rock bulk density γ pi , take samples from each rock layer and measure them by volumetric method;

[0057] Uniaxial compressive strength of each rock layer surrounding the tunnel σ pi , drill cores, take samples from each rock layer, and measure them using a uniaxial compression testing machine.

[0058] The occurrence of rock strata in the roof and floor of the tunnel refers to the material composition, structure, texture and occurrence environment of the rock strata.

[0059] b. Anchor cable support system parameters include but are not limited to:

[0060] b1. Material strength, elongation, diameter, length, anchor length, number of top plate single row anchors R i1 , the spacing of the top plate anchor rods b1, the row spacing of the top plate anchor rods c1, the number of single-row anchor rods in the side part R i2 , the spacing of the side anchors b2, the spacing of the side anchors c2;

[0061] b2. Material strength, elongation, anchor cable diameter, anchor cable length, anchoring length, number of single-row anchor cables on the top plate R i3 , the spacing of the top plate anchor cables b3, the row spacing of the top plate anchor cables c3, the number of single-row anchor cables in the side part R i4 , the spacing of the anchor cables in the side part b4, and the row spacing of the anchor cables in the side part c4.

[0062] S2, according to similarity theory, based on the engineering geological condition parameters of step S1, according to the actual situation of the laboratory, such as the size of the experimental table, etc., set the parameter similarity ratio between the experimental model and the tunnel engineering prototype; according to the experimental materials, determine the bulk density similarity ratio.

[0063] The parameter similarity ratio includes: the geometric similarity ratio C of the experimental model size l, similarity ratio C of rock density of experimental model γ The similarity ratio of uniaxial compressive strength of each rock layer in the experimental model is C σ .

[0064] Set the width and height of the tunnel engineering prototype to b and h respectively a The corresponding width and height dimensions in the experimental model are X m and Y m , then X m =C l *b,Y m =C l *h a ;

[0065] Assume that the bulk density of the i-th rock layer of the tunnel engineering prototype is γ pi , the bulk density of the rock layer in the experimental model is γ mi , then γ mi =C γ *γ pi ;

[0066] Set the unidirectional compressive strength σ of the i-th rock layer of the tunnel engineering prototype pi , the uniaxial compressive strength of the rock layer in the experimental model is σ mi , then σ mi =C σ *σ pi .

[0067] S3, building an experimental model according to step S2, as well as the number and distribution of rock layers of the tunnel surrounding rock in the tunnel engineering prototype, the location of the key layer of the tunnel, and the occurrence of rock layers on the top and bottom plates of the tunnel.

[0068] According to the height of the experimental model and the vertical stress σ of the tunnel engineering prototype h ,After the experimental model is built, the compensating load and lateral constraint are evenly applied on the top of it through the ,electrically controlled hydraulic press that comes with the experimental platform, which is used to ,simulate the formation load on the surrounding rock of the tunnel in the prototype of the tunnel ,engineering.

[0069] The calculation formula for the compensation load is:

[0070] F=σ 顶 s

[0071]

[0072] Where s is the area where the compensating load is applied; γ pi h is the bulk density of each rock layer surrounding the tunnel; i is the thickness of each rock layer not laid in the experimental model; C σ is the similarity ratio of the uniaxial compressive strength of each rock layer in the experimental model.

[0073] S4, based on the similarity theory, based on the anchor cable support system parameters of step S1 and the geometric similarity ratio C of the experimental model size set in step S2 l , intensity similarity ratio C σ , prepare experimental support materials with equivalent strength to the experimental model, including anchor rods, anchor cables, metal mesh, etc.

[0074] The selection of experimental support materials should be determined based on the strength similarity relationship of the materials, and further tensile tests and destructive tests should be carried out on the materials.

[0075] S5, the experimental model is placed under certain environmental conditions, such as preferably an environmental temperature of 20±3°C, a humidity of not less than 50%, and a curing time of ≥7 days, so that the material of the experimental model is hardened to simulate the actual material state of the tunnel engineering prototype; according to the width x of the tunnel in the experimental model m , height Y m , excavating experimental tunnels in the experimental model;

[0076] According to the parameters of the anchor-net cable support system of the tunnel engineering prototype, according to the geometric similarity ratio C of the set experimental model size l , the anchor mesh cable support of the experimental tunnel was completed using the experimental support materials.

[0077] S6, setting a microseismic geophone and a strain gauge in the experimental model, and connecting the microseismic geophone and the strain gauge to a computer to transmit the acquired monitoring data to the computer.

[0078] To ensure that the microseismic geophone can operate well, in this step, the microseismic geophone is set at the anchor bolt and is detachably connected to the anchor bolt through a thread. The stress meter is also set at the anchor bolt.

[0079] In this step,

[0080] a. To prevent resonance, the gap between the anchor bolt and the borehole wall is filled with cementing material;

[0081] b. The microseismic geophone is preferably set at the lower left corner of the experimental tunnel and the upper roof anchor to avoid large errors and to be able to directly detect data at the damaged location;

[0082] c. As attached Figure 2 As shown, during the installation of the microseismic detector probe, the deviation of the anchor bolt should be less than 10°, and its exposed length should be 30mm;

[0083] d. The microseismic detector is equipped with a reinforced safety cover.

[0084] S7, set up the disturbance mechanism in the experimental model.

[0085] The disturbance mechanism comprises a disturbance borehole arranged in the experimental model and a disturbance source arranged in the disturbance borehole. The disturbance source is used to simulate an impact disturbance load and provide disturbance energy to the experimental model.

[0086] The disturbance drilling is set in the upper rock layer of the experimental tunnel according to the key layer height of the tunnel roof in the tunnel engineering prototype. The key layer position is determined according to the key layer theory, and the geometric similarity ratio C is used to determine the key layer position. l To locate the source of disturbance in similar models.

[0087] The disturbance source is preferably TNT explosive, and is detonated by a detonator. During the experiment, the effect of different disturbance energies on the experimental model is studied by adjusting the dosage of TNT explosive, which specifically includes the following steps:

[0088] S71, setting N groups of experimental models and numbering them from 1 to N in sequence;

[0089] S72, after setting disturbance boreholes at the same position of N groups of experimental models and adding a calculated amount of TNT explosives into the disturbance boreholes, the amount of TNT explosives added should be increased group by group;

[0090] S73, the test model is ready, the detonator and the detonating cord are fixed together, loaded into the reserved blast hole of the test model, the hole is sealed, and the detonator is used to detonate, simulating the effect of the impact disturbance dynamic load on the test tunnel;

[0091] S74, observe the damage of the experimental models group by group, and judge whether the anchor mesh cable support system fails and whether the tunnel surrounding rock fails and becomes unstable under the impact disturbance load, and record the impact energy monitoring values ​​transmitted by the microseismic detector and stress gauge one by one.

[0092] In step S72, the amount of TNT explosive added should be selected based on engineering analogy and experimental experience.

[0093] In step S74, the judgment criterion for whether the failure of the anchor-net-cable support system leads to the instability of the tunnel is the large-scale collapse of the experimental tunnel roof, which means that the collapsed area of ​​the tunnel roof is ≧50% of the original area of ​​the roof.

[0094] S8, based on the strain gauge collecting the limit stress value, the microseismic geophone collecting the energy value, according to the energy similarity ratio C E =C σ / 10, the ultimate impact energy value that the anchor-net cable support system in the tunnel engineering prototype can withstand is calculated. According to the ultimate impact energy value, combined with the purpose, service life and other requirements of the coal tunnel, the key parameters of the anchor-net cable support system of the coal tunnel are adjusted to meet the use requirements of the tunnel.

[0095] The following takes a rock burst mine as an example and combines the attached Figure 1 , the experimental method recorded in the present invention is further described:

[0096] S1, conduct field research on the tunnel engineering prototype of the rock burst mine, and obtain the following parameters:

[0097] a. Engineering geological conditions parameters:

[0098] The tunnel width b is 6m and the height h a 4.2m, burial depth h b 600m;

[0099] Vertical stress of the stratum where the tunnel is located σ h 17.6MPa;

[0100] The number of rock layers surrounding the tunnel is 4;

[0101] The rock layers of the tunnel roof and floor are sandstone, which is relatively hard.

[0102] Tunnel surrounding rock bulk density γ pi , the uniaxial compressive strength of each rock layer is σ pi , the location of key layers in the tunnel.

[0103] b. Anchor net cable support system parameters:

[0104] The anchor rod material strength is 500MPa, the elongation is 16%, the anchor rod diameter is 22mm, the anchor rod length is 2400mm, the anchoring length is 1000mm, and the number of single-row anchor rods on the top plate is R i1 The number of anchor rods in a single row is R. i2 There are 5 anchor rods, the spacing b2 of the side anchor rods is 800mm, and the row spacing c2 of the side anchor rods is 1000mm;

[0105] The anchor rod material strength is 1860MPa, the elongation is 3%, the anchor diameter is 21.8mm, the anchor length is 6000mm, the anchor length is 2200mm, and the number of single-row anchors on the top plate is R i3 There are 2 top plate anchor cables, the spacing b3 of the top plate anchor cables is 1900mm, and the spacing c3 of the top plate anchor cables is 2000mm.

[0106] S2, set the geometric similarity ratio C of the experimental model size l The rock density similarity ratio C of the experimental model is 1:30. γ is 1:1.5, and the similarity ratio of uniaxial compressive strength of each rock layer in the experimental model is C σ is 1:45.

[0107] The experimental model was constructed using materials similar to those used in the tunnel engineering prototype. The experimental model materials are: fine river sand as aggregate, calcium carbonate and gypsum as binder materials, and mica powder as layering material. The material consumption calculation formula for building the model is:

[0108]

[0109] Where:

[0110] Q—total material consumption of the experimental model, kg;

[0111] k—Material loss coefficient due to paving and other reasons;

[0112] ρ—density of the material used for the paving test model, kg / m 3 ;

[0113] l m —Experimental model strike size, m;

[0114] b m —Longitudinal dimension of the experimental model, m;

[0115] m i —Thickness of the rock layer in the experimental model, m, assuming that n layers are laid.

[0116] S3, build the experimental model, the overall size of the experimental model is: length 1500mm×width 400mm×height 1200mm. After the experimental model is built, a compensation load of 208.2kN is evenly applied on the top.

[0117] S4, through strength similarity relationship, pull-out test and destructive test, Φ1.0mm tin wire was selected to make anchor rods, anchor cables and metal mesh.

[0118] S5, after laying and drying the experimental model, the experimental tunnel is excavated; the cross-sectional dimensions of the experimental tunnel are: length 200mm × width 140mm. The experimental tunnel is supported by anchor rods, anchor cables and metal mesh made of tin wire.

[0119] S6, as attached Figure 1 As shown, microseismic detectors are arranged at the lower left corner and the upper roof of the tunnel, and it is ensured that during the installation of the probe, the bolt deviation should be less than 10° and the exposed length should be 30mm; the stress gauge is also arranged at the same position.

[0120] S7, conduct large-scale physical model tests and use TNT explosives to simulate rock burst.

[0121] In this step, four groups of experimental models are set up. According to the geometric similarity ratio of the experimental model size of 1:30, engineering analogy method and experimental experience, the amount of TNT explosive disturbance added to the preset borehole of the experimental model is determined to be 3gTNT, 6gTNT, 9gTNT, and 12gTNT respectively, which are increased in groups.

[0122] During the dynamic load disturbance of the four experimental models, it was observed that the roof of the tunnel of the fourth experimental model collapsed in a large area, and the tunnel support system was determined to be failed. According to the monitoring data sent back by the microseismic detector and the stress meter, the stress value that the tunnel anchor cable support system can withstand is 2.53×10 2 J.

[0123] S8, according to the energy similarity ratio C E =C σ / 10, and the ultimate impact energy value that the tunnel support system of the rock burst mine can withstand is 1.14×10 5 J. The service life of the coal roadway in the rock burst mine is 5 years. It is judged that the anchor net cable support system of the coal roadway in the rock burst mine has reached the use standard and meets the requirements for the use of the roadway, and no adjustment is required.

[0124] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for evaluating the impact resistance of an anchor-net cable support system in a coal tunnel of a rock burst mine, characterized in that: The following steps are involved: S1: Conduct field research on rock burst mines to obtain the engineering geological condition parameters and anchor-net cable support system parameters of the tunnel engineering prototype; S2, build an experimental model based on similarity theory and the engineering geological condition parameters, where: Setting the geometric similarity ratio between the experimental model and the tunnel engineering prototype, the similarity ratio of the bulk density of each rock layer, and the similarity ratio of the unidirectional compressive strength of each rock layer; The number and distribution of rock layers, the location of key layers in the tunnel, and the occurrence of rock layers in the tunnel roof and floor are set to be the same or approximately the same as those in the tunnel engineering prototype; S3, applying a compensation load of a set value to the top of the experimental model to simulate the formation load on the surrounding rock of the tunnel in the tunnel engineering prototype; S4, preparing experimental support materials for the experimental model based on similarity theory, parameters of the anchor mesh cable support system, and the geometric similarity ratio and strength similarity ratio; S5, after the experimental model has been cured to meet the experimental requirements, excavating an experimental tunnel in the experimental model according to the geometric similarity ratio, and using the experimental support material in the experimental tunnel to complete tunnel support; S6, setting a microseismic geophone and a strain gauge in the experimental model, wherein the microseismic geophone and the strain gauge are connected to a computer to transmit the acquired monitoring data to the computer; S7, sequentially setting disturbance boreholes at the same positions of the N experimental models, and respectively setting disturbance sources in the disturbance boreholes, wherein the disturbance sources are used to provide impact disturbance loads to the experimental models where they are located; The N experimental models are observed respectively, and the data transmitted by the microseismic detectors and stress gauges in the instability experimental models are collected to calculate the ultimate impact energy value that the anchor mesh cable support system in the tunnel engineering prototype can withstand.

2. The method for evaluating the impact resistance of the anchor-net cable support system in a coal roadway of a rock burst mine according to claim 1 is characterized in that: A compensation load is uniformly applied to the top of the experimental model, and the numerical calculation formula of the compensation load is: F=σ 顶 s Where s is the area where the compensating load is applied; γ pi h is the bulk density of each rock layer surrounding the tunnel; i is the thickness of each rock layer; C σ is the similarity ratio of the uniaxial compressive strength of each rock layer in the experimental model.

3. The method for evaluating the impact resistance of the anchor-net cable support system in a coal roadway of a rock burst mine according to claim 1 is characterized in that: The experimental requirements are: ambient temperature is 20±3°C, humidity is ≧50%, and curing time is ≧7 days.

4. The method for evaluating the impact resistance of the anchor-net cable support system in a coal roadway of a rock burst mine according to claim 1 is characterized in that: The experimental support material is determined based on a pull-out test, a destructive test and a strength similarity relationship of the materials.

5. The method for evaluating the impact resistance of the anchor-net cable support system in a coal roadway of a rock burst mine according to claim 1 is characterized in that: The microseismic geophone and the stress meter are arranged at the anchor bolt in the experimental support material, and the gap between the anchor bolt and the hole wall of the anchor borehole is filled with bonding material.

6. The method for evaluating the impact resistance of the anchor-net cable support system in a coal roadway of a rock burst mine according to claim 5 is characterized in that: During the installation of the probe of the microseismic geophone, the deviation of the anchor bolt is less than 10°, and the exposed length thereof is set to 30 mm.

7. The method for evaluating the impact resistance of the anchor-net cable support system in a coal roadway of a rock burst mine according to claim 5 is characterized in that: The microseismic geophones are arranged at the lower left corner of the tunnel and the upper roof anchor of the experimental model.

8. The method for evaluating the impact resistance of the anchor-net cable support system in a coal roadway of a rock burst mine according to claim 1 is characterized in that: Step S7 includes the following sub-steps: S71, setting the numbers of N experimental models to 1 to N; S72, the disturbance source is set to TNT explosives, and TNT explosives are added to 1 to N disturbance boreholes of the experimental model in sequence; S73, fix the detonator and the detonating cord together and install them into the blast hole reserved in the experimental model, seal the hole, and use the detonator to detonate to simulate the effect of the impact disturbance dynamic load on the experimental tunnel; S74, observe the damage of the experimental models group by group, and determine whether the anchor net cable support system has suffered impact damage or instability, and record the impact energy monitoring values ​​transmitted by the microseismic detector and stress gauge.

9. The method for evaluating the impact resistance of the anchor-net-cable support system of coal roadway in rock burst mine according to claim 8, characterized in that: The amount of TNT explosive added is selected based on engineering analogy and experimental experience; the criterion for judging the instability of the anchor mesh cable support system is that the collapsed area of ​​the roof of the experimental tunnel is ≧ 50% of the original area of ​​the roof.

10. The method for evaluating the impact resistance of the anchor-net-cable support system of coal roadway in rock burst mine according to claim 1, characterized in that: The energy value collected by the microseismic detector in the instability experimental model and the limit stress value collected by the stress gauge are collected according to the energy similarity ratio C E =C σ / 10, and the ultimate impact energy value that the anchor-net-cable support system in the tunnel engineering prototype can withstand is calculated.

11. The method for evaluating the impact resistance of the anchor-net-cable support system of coal roadway in rock burst mine according to claim 1, characterized in that: During the construction of the experimental model, the construction materials used in the experimental model are similar to the materials of the tunnel engineering prototype; the material consumption calculation formula for building the model is: Where: Q is the total material consumption of the experimental model, kg; k is the material loss coefficient due to paving; ρ is the density of the material used to pave the experimental model, kg / m 3 ; l m —Experimental model direction size, m; b m —Longitudinal dimension of the experimental model, m; m i —Thickness of the i-th rock layer in the experimental model, m.

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