CN112082859A - A simulation method to ensure the safety of dual-level and dual-stage mining in mines - Google Patents

Abstract

The invention relates to the technical field of mining methods, in particular to a simulation method for guaranteeing the safety of double-level and double-stage mining of a mine. The method comprises the following steps: carrying out an indoor rock mechanical test to obtain physical mechanical parameters of typical rock mass and structure in a mining area; researching the mutual disturbance effect of the two-level two-stage simultaneous mining of the iron ore, and acquiring the mutual influence rule of the upper mining area and the lower mining area in the two-stage simultaneous mining process; studying the effect of designing and reserving 20m horizontal ore pillars between the upper mining area and the lower mining area on maintaining the overall stability of a stope and controlling the mutual disturbance influence between the upper mining area and the lower mining area; researching the structural parameters and the mining sequence of the deep stope, proposing a mining sequence which preferably adopts one mining at intervals, and adopting a mining sequence which adopts one mining at intervals for the broken surrounding rock; the disturbance effect of mining on adjacent faults is studied and analyzed. By the aid of the simulation analysis before mining, safety of mining production is guaranteed, and continuity and stability of future mine production are guaranteed.

Description

A simulation method to ensure the safety of dual-level and dual-stage mining in mines

technical field

The invention relates to the technical field of mining methods, in particular to a simulation method for ensuring the safety of dual-level and dual-stage mining in mines.

Background technique

Due to the failure to use advanced mining equipment and mining methods, improper mining affects the equilibrium conditions of the formation, especially for structures with strong rock weathering and multi-stage and repetitive activities.

In addition, when the mining depth is large and the ground stress is high, compared with the shallow mines, the occurrence of ore bodies has changed greatly, and the engineering geological conditions have become more complicated. The body is broken, the tectonic activity is strong, and the bedrock is damaged by different degrees of tension or extrusion, and the water permeability and water richness are enhanced. Therefore, the disturbance effects of the upper and lower horizontal mining will be superimposed on each other, which may not only affect the mechanical properties of the surrounding rock and the change of the stress environment, but also cause the multi-field coupling effect, which may lead to the concentration of local stress, the accumulation of energy in local areas and the formation of rock formations in larger areas. The large-scale adjustment and movement of the mine will induce mining dynamic disasters such as rock bursts, roof fall, gangbangs, and water inrush.

The existing patent document CN102155227A discloses a continuous mining method in the vertical direction and its application in the continuous mining of the whole ore body. Balanced production, and no horizontal ore pillars are reserved between the mining and filling stages, which effectively reduces the loss of horizontal ore pillar ore volume between stages, and also ensures safe mining and effective connection of each middle stope. However, this technical solution It only pays attention to the setting of the ore pillars in the mine room, and simply calculates the pressure yield of the backfill body through mechanics, without comprehensively considering the geological conditions, multi-ore bodies, and multi-level mining sequences on mining disturbance and its structural hazards. question.

SUMMARY OF THE INVENTION

The invention aims to overcome the problems of multi-field action of mining disturbance and its structural disaster-causing effect that may exist between multiple ore bodies, between shallow stopes and deep stopes, and between ore bodies and faults; in order to solve the above problems, The purpose is to provide a simulation method to ensure the safety of dual-level and dual-stage mining in mines.

In order to achieve the above purpose, the technical solution adopted is a simulation method for ensuring the safety of dual-level and dual-stage mining in mines, comprising the following steps:

Step 1. Carry out indoor rock mechanics test to obtain physical and mechanical parameters of typical rock mass and structure in the mining area;

Step 2, carry out the analysis of the mutual disturbance effect of the two-level and two-stage simultaneous mining, and obtain the mutual influence law of the upper and lower mining areas during the two-stage simultaneous mining process;

Step 3. Leave horizontal ore pillars between the upper and lower mining areas;

Step 4: Carry out the optimization analysis on the structural parameters of the deep stope and the mining sequence, and propose that the mining sequence of every other mining should be preferentially adopted, and the mining sequence of every second mining and one mining should be adopted for the broken surrounding rock section;

Step 5: Analyze the disturbance effect of mining on adjacent faults.

Further, the indoor rock mechanics test in the first step includes a uniaxial compression test, a split tensile test, a rock triaxial compression test, and a direct shear test of the rock mass structure in the fault fracture zone.

Further, the step 2 includes numerical simulation analysis of the stability of the middle stope at different levels, and the numerical model is as follows: the lower middle stope and the upper middle stope, the upper middle stope is mined first, and the stope ore body adopts the medium depth. The mining method of hole blasting and subsequent filling mining, mining every other, the first step is the mining house, and the calculation is to balance; then the mining house is cemented and filled, which is used as the pillar of the stope in the second step, and the calculation is balanced; the second step is back to Mining pillar, calculate to balance; then fill the ore pillar area with tailings and calculate to balance; after the upper middle section is mined, the lower middle section is mined again, and the mining method is the same as the upper middle section.

Further, in the third step, the thickness of the horizontal ore pillar is obtained by combining the ultimate equilibrium strength theory and the stress condition to solve the reserved ore pillar safety thickness h; the width of the horizontal ore pillar is a, the length of the horizontal ore pillar is b, and the ultimate tensile strength is σ _r , Poisson’s ratio is v, and the uniform load of the upper backfill to the horizontal pillar is q, the safety thickness h of the reserved pillar is obtained;

Further, the expression of the reserved mine pillar safety thickness h is:

Further, according to the experience of producing mines of the same type in the step 4, the mining order of the ore blocks is every other mining one and every two mining one, and combined with the Mathews stability diagram method to analyze the width of the ore nuggets, according to different mining sequences and mines. Block width, adopt different combination schemes for data simulation optimization analysis.

Further, in the step 5, the disturbance action of the adjacent fault is analyzed according to the Coulomb disturbance stress model and its dynamic characteristic criterion.

Further, the dynamic characteristic criterion in the step 5 includes a fault failure disturbance stress criterion, a fault disturbance failure coulomb stress area criterion, and a fault disturbance Coulomb stress gradient criterion.

Compared with the prior art, the present invention has the following advantages: the present invention utilizes FLAC ^3D simulation to carry out research on the mining of iron ore ore bodies with deep burial and large mining range, and focuses on the double-level development layout of mines, and the upper part in the double-stage mining process. The evolution process and overlapping relationship in time and space of the mining disturbance area and the deep mining disturbance area, analyze the changes of multiple fields in the deep and shallow mining disturbance area, analyze the activation effect of the fault, and quantitatively evaluate the potential insecurity in the mining process Factors and their disaster-causing mechanisms and dangers provide a guarantee for ensuring production safety and maintaining the continuity and stability of mine production in the future.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

Fig. 1 is a simulation calculation model of dual-level dual-stage mining of the present invention;

Figure 2 shows the impact on the middle section of -780m and -720m when the lower stage of the present invention is mined;

Fig. 3 is the influence on the middle section of -660m and -600m when the lower stage of the present invention is mined;

Fig. 4 is the 15m vertical stress diagram and the 15m minimum principal stress diagram of the present invention;

Fig. 5 is the 15m vertical displacement diagram and the 18m vertical stress diagram of the present invention at every mining time;

Fig. 6 is the 18m minimum principal stress diagram and the 18m vertical displacement diagram of the present invention;

Fig. 7 is the 21m vertical stress diagram and the 21m minimum principal stress diagram of the present invention;

Fig. 8 is the 21m vertical displacement diagram and the 24m vertical stress diagram of the present invention every one mining time;

Fig. 9 is the 24m minimum principal stress diagram and the 24m vertical displacement diagram of the present invention;

Fig. 10 is the 15m vertical stress diagram and the 15m minimum stress diagram of the present invention every two mining periods;

Fig. 11 is the 15m vertical displacement diagram and the 18m vertical stress diagram of the present invention every two mining periods;

Figure 12 is the 18m minimum principal stress diagram and the 18m vertical displacement diagram of the present invention;

Figure 13 is the 21m vertical stress diagram and the 21m minimum principal stress diagram of the present invention at intervals of two mining operations;

Fig. 14 is the 21m vertical displacement diagram and the 24m vertical stress diagram of the present invention every two mining periods;

Figure 15 is the 24m minimum principal stress diagram and the 24m vertical displacement diagram of the present invention;

Fig. 16 is the incremental distribution of Coulomb disturbance stress on the fault plane when the present invention excavates -180m and -240m;

Fig. 17 is the incremental distribution of Coulomb disturbance stress on the fault plane when excavating -420m and -540m according to the present invention;

Figure 18 shows the incremental distribution of Coulomb disturbance stress on the fault plane when excavating -600m in the present invention.

Detailed ways

The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings.

The following examples are aimed at Macheng Iron Mine. The ore body of Macheng Iron Mine is generally NW-oriented, layered, inclined to NW or SW, with an inclination angle of 39-56° and an overall strike length of 6km. The ore bodies are layered, layer-like, and large-lens-like. Among the 15 ore bodies divided in the whole area, the ore bodies I, II and V are the largest in scale, with strike lengths of 1750m, 1210m and 2100m respectively. Thickness (the same below) are 36.35m, 127.56m and 83.90m respectively. The preliminary design determines the mining range to be -240m～-900m, and is divided into 2 mining areas, of which -240m～-540m is the upper mining area, -540m～-900m is the lower mining area, and the upper and lower mining areas are mined at the same time.

Example 1

The present embodiment carries out the mechanical test to the rock:

Step 1. Uniaxial compressive test: The uniaxial compressive deformation parameters of the rock mass were measured using the GAW-2000 microcomputer-controlled electro-hydraulic servo rigid pressure testing machine in the Rock Mechanics Laboratory of the University of Science and Technology Beijing. A total of 12 rock samples were tested. Tests, including diabase, granite (-530, -930m), iron ore, etc., test 3 pieces each, and measure their uniaxial compressive strength, Poisson's ratio and elastic modulus. The test results are in Table 1 and Table 2. and as shown in Table 3:

The formula for calculating the compressive strength of the rock is:

The above σ _c is the uniaxial compressive strength of the rock, P is the maximum load when the sample fails, and A is the cross-sectional area of the sample.

The Poisson's ratio of the rock is calculated as

where ε _aa is the longitudinal strain value when the stress is σ _a , ε _ab is the longitudinal strain value when the stress is σ _b , ε _ca is the transverse strain value when the stress is σ _a , and ε _cb is the transverse strain value when the stress is σ _b strain value.

The elastic modulus of the rock is calculated as

where E _av is the elastic modulus of the rock (MPa), μ _av is the Poisson’s ratio of the rock, σ _a is the stress value at the starting point of the straight line segment on the stress-strain relationship curve (MPa), and σ _b is the straight line on the stress-strain relationship curve Stress value (MPa) at the end of the segment.

Table 1

Table 2

table 3

Step 2. Splitting tensile test: The Brazilian splitting test of the rock mass was measured by the Gaw2000 pressure testing machine of the Rock Mechanics Laboratory of the University of Science and Technology Beijing. A total of 18 rock samples were tested, and the test results are shown in Table 4:

The formula for calculating the tensile strength of the rock is

where σ _t is the tensile strength of the rock (MPa), P is the failure load (N), D is the diameter of the sample (mm), and L is the height of the sample (mm).

Table 4

其测试结果如表5所示：Step 3. Rock triaxial compression test: Triaxial compression test. Generally, under the same water content state, different lateral pressures are applied to the specimens respectively. These specimens are damaged under the continuous loading of axial load, and the axial failure stress is obtained. σ ₁ , c,

The test results are shown in Table 5:

The calculation formula of the axial failure stress σ ₁ is σ ₁ =P/A.

Among them, P is the maximum failure load of the rock specimen, N and A are the compression area of the specimen, mm ² ;

For the relationship between σ ₁ and σ ₃ , the linear regression equation is σ ₁ =σ _c +kσ ₃ .

Where σ _c is the stress intercept of the ordinate of the relationship between σ ₁ and σ ₃ , MPa, K is the slope of the relationship between σ ₁ and σ ₃ .

值计算公式分别为

the c.

The value calculation formulas are

为岩石的内摩擦角，°。where c is the cohesion of the rock, MPa;

is the internal friction angle of the rock, °.

table 5

Step 4. Before loading the normal and tangential loads, place the specimen on the shear tester to ensure that the shearing direction of the specimen is consistent with the stressing direction of the engineering rock mass. First install the normal hydraulic jack, then install the hydraulic jack in the shear direction to ensure that the normal load and the tangential load pass through the geometric center of the structural surface, and finally install the gauge; the normal load is loaded step by step from small to large. They are: 0.2MPa, 0.4MPa, 0.6MPa, 0.8MPa; after the normal stress loading is stable, the estimated maximum shear load is divided into 10 to 12 grades. When the shear displacement increases significantly, the level difference can be appropriately reduced; when the shear displacement increases significantly, the relationship between shear stress and shear displacement When there is an obvious sudden change on the curve, it can be considered that a shear process has been completed; however, due to the complexity of the shear properties of the natural structural plane, the curve of the relationship between shear stress and shear displacement is likely to have no obvious peak. It can be considered that a shear is completed when the total shear displacement reaches 8mm. The results of the direct shear test on the rock structure are shown in Table 6:

Table 6

Example 2

In this example, the research on the mutual disturbance effect of the two-level and two-stage simultaneous mining of iron ore is carried out through the computer program FLAC ^3D simulation calculation, and the mutual influence law of the upper and lower mining areas during the two-stage simultaneous mining process is obtained. The research shows that the two-level and two-stage simultaneous mining The mining plan is feasible; its steps are as follows:

Step 1. Use the computer program FLAC ^3D to simulate and calculate the mutual disturbance effect of iron ore dual-water dual-stage mining. The mechanical parameters of the specific filling body are shown in Table 7 and Table 8:

Table 7

Table 8

Step 2: Simulate dual-level dual-stage simultaneous mining, divide the ore body into two mining areas, the lower mining area is -900m to -540m, and the upper mining area is -540m to -180m. The two areas are simultaneously mined from the bottom to the top. Each mining area is divided into several stages, and the height of each mining stage is 60m.

Step 3: Simulate single-stage mining, that is, mining from the bottom up from the -900m level, and the height of each mining stage is 60m.

Referring to Figures 2 to 3 in the description, it can be seen from the change of the maximum principal stress in the dual-level and dual-stage simultaneous mining that the stress in the upper mining area hardly changes before the lower mining area is mined to the mid-level of -660m, indicating that the lower mining area hardly changes. The mining of the mining area causes little disturbance to the upper part. When the middle section of the -660 level is mined, a certain stress change is caused in the stope in the middle section of -540m in the upper part, which shows that the stress of the surrounding rock in the stope decreases, but at -540m The disturbance effect is not obvious in the above horizontal middle section; when the lower mining area is mining the -600 horizontal middle section, certain stress changes are caused in the upper -540m and -480 middle section stopes, but the disturbance stress in the -480 middle section is relatively high. Small. It can be seen from the vertical displacement distribution of simultaneous mining in two horizontal and two stages that before the lower mining area is mined to the middle section of 720m, the mining displacements of the upper and lower mining areas are basically distributed independently according to their respective evolution laws, and there is no impact on the intersection area. After the middle section of 720m is mined, The subsidence area of the lower mining area has a certain intersection with the upper stope, but the displacement caused by the upper mining area is very small. Until the middle -660m mining, the mining displacement disturbance range of the upper and lower mining areas does not overlap significantly. From the above analysis, it can be seen that the dual-level dual-stage simultaneous mining has less impact than the single-stage mining, that is, the dual-level dual-stage simultaneous mining scheme in step 2 is feasible.

The step two iron ore double horizontal and double stage includes numerical simulation analysis of the stope stability of the -600m middle section and -540m middle section. The numerical model is as follows: the lower -600 middle section stope and the upper -540 middle section stope, the -540 In the middle stope, the ore body of the stope adopts the mining method of medium-deep hole blasting and then backfilling. Mining every other, the first step is to mine the 18m mine house and calculate it to balance; then the mine house is cemented and filled as step 2 The ore pillar of the stope is calculated to balance; the second step is to recover the 18m ore pillar, and the calculation is to balance; then the tailings are filled in the ore pillar area, and the calculation is to balance; after the -540 middle section is mined, the -600 middle section is mined again. Its mining method is the same as that of the -540 middle section.

Example 3

This example analyzes the effect of designing and setting 20m horizontal ore pillars between the upper and lower mining areas to maintain the overall stability of the stope and control the mutual disturbance of the upper and lower mining areas. The steps are as follows:

Step 1: Simplify the horizontal ore pillar into a thin plate fixed on four sides, and combine the ultimate equilibrium strength theory with the stress conditions to obtain the relationship between the required thickness of the horizontal ore pillar and the stope span.

带入参数，计算出h。Step 2: Solve the expression of the required thickness h of the horizontal ore pillar when the width of the horizontal ore pillar is a and the length is b, and the uniform distribution load of the upper filling to the horizontal ore pillar is q, and the expression of the reserved pillar safety thickness h According to the formula

Bring in the parameters and calculate h.

The a is the length of the horizontal ore pillar, b is the width of the horizontal ore pillar, v is the Poisson's ratio, q is the load, and σ _t is the tensile strength of the rock.

The a is 43m, b is 130m, σ _t is 0.67MPa, and v is 0.2. Substituting the above parameters into the solution, h is 18.7m, that is, the 20m-thick horizontal ore pillar can still be maintained after the orebodies in the lower ore house are mined. Stablize. In summary, the 20m-thick horizontal pillar between the upper and lower stopes is sufficient to maintain the overall stability of the stope.

Example 4

In this embodiment, the Mathews stability diagram method and the computer program FLAC ^3D are used to optimize the analysis of the structural parameters of the deep stope and the mining sequence. According to the analysis results of Mathews stability diagram method, the ore block widths are 15m, 18m, 21m and 24m respectively. According to different mining sequences and ore block widths, there are 8 combination schemes, as shown in Table 9:

Table 9

It can be seen from the FLAC ^3D simulation results that compared with the mining sequence of every other mining one, the mining sequence of every other mining is actually equivalent to increasing the width of the pillars between adjacent mining houses, which reduces the degree of mining disturbance. It is more beneficial to improve the stability of the mine empty area.

Referring to Figures 4 to 15 in the description, when the width of the mine house is 15m, the upper surrounding rock load is mainly supported by the ore pillar and the surrounding rocks on both sides. In the mine pillar, it is 33.8MPa; the maximum tensile stress of the roof and floor appears in the middle of the roof and floor, which is 2.72MPa, which is less than the tensile strength of the rock mass, indicating that the roof and floor have no tensile failure; the maximum vertical displacement of the roof of the mine occurs in the stope The middle part is 10.5mm;

When the width of the ore house is 18m, the upper surrounding rock load is mainly supported by the ore pillar and the surrounding rocks on both sides. The stress concentration occurs in the ore pillar and the surrounding rocks on both sides, and the maximum stress value appears in the ore pillar, which is 35.3MPa; The tensile stress appears in the middle of the roof and floor, which is 2.89MPa, which is less than the tensile strength of the rock mass, indicating that the roof and floor have no tensile failure; the maximum vertical displacement of the roof of the mine occurs in the middle of the stope, which is 12.2mm;

When the width of the mine house is 21m, the load of the upper surrounding rock is supported by the ore pillar and the surrounding rocks on both sides. The stress concentration occurs in the ore pillar and the surrounding rocks on both sides. The maximum stress value between the two is not much different. 36.3MPa; the maximum tensile stress of the roof and floor appears in the middle of the roof and floor, which is 3.06MPa, which is close to the tensile strength of the rock mass, indicating that the roof and floor have tensile failure; the maximum vertical displacement of the roof of the mine occurs in the middle of the stope, which is 13.8mm ;

When the width of the mine is 24m, the load of the upper surrounding rock is supported by the ore pillar and the surrounding rocks on both sides. The ore pillar and the surrounding rocks on both sides have stress concentration, and the maximum stress value is 37.5MPa; the maximum tensile stress of the roof and floor appears in the roof and floor. In the middle, it is 3.06MPa, which is close to the tensile strength of the rock mass, indicating that the roof and floor have tensile failure, and the damage range is further expanded; the maximum vertical displacement of the roof of the mine house occurs in the middle of the stope, which is 15.2mm.

By comprehensively analyzing the above results, it can be concluded that the mining disturbances in different combination schemes are shown in Table 10:

Table 10

It can be seen from Table 10 combined with the FLAC ^3D simulation that when the mining sequence of the mining house is every other mining, with the increase of the stope span, the maximum stress in the mine pillar increases continuously, the displacement of the roof and floor also increases gradually, and the maximum tensile force in the roof and floor increases. The stress increases first and then remains unchanged, and the distribution range of the maximum tensile stress increases with the increase of the span, indicating that the tensile failure range of the roof and floor increases with the increase of the span. The maximum vertical displacement of the roof and the roof of the mine increases with the increase of the width of the mine, and the maximum tensile stress of the roof and floor first increases to the tensile limit of the rock mass and then remains unchanged; The mining sequence of every two mining one is equivalent to increasing the width of the ore pillar to a certain extent, so that the aspect ratio of the ore pillar is increased, the stability of the ore pillar is enhanced, and the stress concentration in the ore pillar is reduced.

Comprehensive analysis of the above results shows that when the width of the mine pillar is 15m and 18m, it is better than 21m and 24m, but when the width of the mine house is 15m, the small size is not conducive to the stability of the stope in the later stage and affects the mining efficiency of the mine. The reasonable width of the mine house is 18m, and the mining sequence of every other mining is preferred. When the ore pillar is relatively stable, the mining sequence of every other mining is adopted.

Example 5

In this example, the disturbance effect of mining on adjacent faults is analyzed, and the research shows that retaining pillars can effectively control the disturbance of mining on faults.

According to the disturbance stress criterion of fault failure, the Coulomb stress area criterion of fault disturbance failure and the Coulomb stress gradient criterion of fault disturbance, the FLAC3D numerical software was used to analyze the mining disturbance effect of adjacent faults in the lower ore body of iron ore.

Referring to Figures 16 to 18 in the description, the analysis results show that the Coulomb disturbance stress of the fault near the stope varies greatly, that is, there are areas where the disturbance stress increases and also decreases, and the reduced areas are mainly distributed at the same level as the working face. On the fault plane, the area of increased disturbance stress is distributed on the fault plane in the lower area of the bottom of the working face. The analysis shows that the mining of the lower middle section has aggravated the fault disturbance near the stope in the upper middle section to a certain extent, so that the area has a large accumulation of large amount of energy. Therefore, during the excavation of the tunnel at the bottom of the upper working face and the advancement of the lower working face, attention should be paid to strengthening the safety precautions in the area near the fault, especially the tunnel face part of the tunnel near the fault is just parallel to the tangential direction of the fault. It is easy to produce tangential stress concentration, which leads to ganglion and even large rock burst activities. However, due to sufficient fault protection pillars, it can be seen from the distribution of normal stress and tangential stress on the fault plane that mining will not cause large fault areas. activation.

In the example, the mechanical test of the rock was first carried out, and the uniaxial compressive strength, elastic modulus, Poisson's ratio, tensile strength, internal friction angle and other data were measured, which provided the basis for the subsequent numerical simulations of geological and mechanical parameters; The invention designs the iron ore as dual-level and dual-stage simultaneous mining, that is, the dual-level and dual-level simultaneous upward mining at -900m and -540m, and the overlapping effect will be produced when the mining disturbance zone of each level has an impact on this horizontal stage. Before, it is necessary to simulate the stable relationship of dual-level and dual-stage mining. Through analysis, it can be seen that in the process of dual-stage simultaneous upward mining, the impact of the lower part on the upper part is small, and the main influence of the upper part on the lower part is in the mining of the middle section of -600, the lower mining area and the upper mining area. The stability of the left 20m protective layer roof is the key to the stability of the two-stage mining, and then the stability of the horizontal ore pillar is analyzed by the roof force, and it is calculated that the 20m horizontal ore pillar is sufficient to maintain the overall stability of the stope; the mining stability is in addition to It is related to objective factors such as surrounding rock properties and geological structure, as well as stope structure parameters and the mining sequence of the mining house, and then simulates the impact of different mining sequences on mining disturbances, and finds that the iron ore stage will subsequently fill the stope with reasonable mining houses. The width is 18m, and the mining sequence of every two mining and one mining is preferred. When the ore pillar is relatively stable, the mining sequence of every other mining is adopted. Moreover, due to the complex mechanical properties of the rock mass at the fault, when the additional stress increases to a certain extent, When a large geological disaster occurs, the Coulomb disturbance stress change of the ore body adjacent to the fault is simulated by the criterion theory, and it is found that because enough faults are left to protect the ore pillar, it can be known that the mining will not cause large-scale activation of the fault.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that , the technical solutions of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims (7)

1. a simulation method of guaranteeing the safety of double-level and double-stage mining in mines, is characterized in that, comprises the following steps: Step 1. Carry out indoor rock mechanics test to obtain physical and mechanical parameters of typical rock mass and structure in the mining area; Step 2, carry out the analysis of the mutual disturbance effect of the two-level and two-stage simultaneous mining, and obtain the mutual influence law of the upper and lower mining areas during the two-stage simultaneous mining process; Step 3. Leave horizontal ore pillars between the upper and lower mining areas; Step 4: Carry out the optimization analysis on the structural parameters of the deep stope and the mining sequence, and propose that the mining sequence of every other mining should be preferentially adopted, and the mining sequence of every second mining and one mining should be adopted for the broken surrounding rock section; Step 5: Analyze the disturbance effect of mining on adjacent faults. 2. A kind of simulation method for guaranteeing the safety of dual-level and dual-stage mining in mines according to claim 1, is characterized in that, in described step 1, indoor rock mechanics test comprises uniaxial compression test, splitting tensile test, rock Triaxial compression test and direct shear test of rock mass structure in fault fracture zone. 3. a kind of simulation method of guaranteeing the safety of mine double-level and double-stage mining according to claim 1, is characterized in that, described step 2 comprises numerical simulation analysis of the stope stability of different levels in the middle section, and the numerical model is as follows: the middle section of the lower part For the stope and the upper middle stope, the upper middle stope is mined first, and the stope ore body adopts the method of medium-deep hole blasting and then filling and mining. The ore house is cemented and filled, as the pillar of the stope in the second step, and calculated to equilibrium; the second step is back to the mining pillar, and the calculation is in equilibrium; , and then the lower middle section is mined, and the mining method is the same as that of the upper middle section. 4. a kind of simulation method of guaranteeing the safety of dual-level dual-stage mining in mines according to claim 1, is characterized in that, in the described step 3, the thickness of the horizontal pillar is to solve the reservation in combination with the ultimate equilibrium strength theory and the stress condition. The safe thickness of the pillar is h; in which the width of the horizontal pillar is a, the length of the horizontal pillar is b, the ultimate tensile strength is σ _r , the Poisson’s ratio is v, and the uniform load of the upper backfill to the horizontal pillar is q. , find out the safety thickness h of the reserved pillar; The expression of the safety thickness h of the reserved pillar is:

5. a kind of simulation method of guaranteeing the safety of dual-level and dual-stage mining in mines according to claim 1, is characterized in that, in the described step 4, according to the experience of producing mines of the same type, the mining order of ore nuggets is every other mining and a sum. Mining every two, and combining the Mathews stability diagram method to analyze the width of ore blocks, according to different mining sequences and ore block widths, different combination schemes are adopted for data simulation optimization analysis. 6. a kind of simulation method of guaranteeing the safety of mine dual-level dual-stage mining according to claim 1, is characterized in that, in described step 5, the disturbance action of adjacent fault is carried out according to Coulomb disturbance stress model and dynamic characteristic criterion thereof. analyze. 7. a kind of simulation method of guaranteeing the safety of mine dual-level and dual-stage mining according to claim 6, is characterized in that, in described step 5, dynamic characteristic criterion comprises fault failure disturbance stress criterion, fault disturbance disturbance amount coulomb Stress area criterion and Coulomb stress gradient criterion for fault disturbance.

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