Stope structure parameter evaluation and optimization method based on goaf big data

Abstract

The invention discloses a stope structure parameter evaluation and optimization method based on goaf big data, and the method comprises the steps: analyzing the goaf collapse type and size through a goaf big data model, visually analyzing the cause of goaf collapse, and determining the stability of a goaf; analyzing safety coefficients of goaf roofs and pillars according to a theoretical formula, and comparing the safety coefficients with the goaf big data model to analyze whether the safety coefficients are consistent; the stope structure parameters are preliminarily determined through theoretical calculation and a big data model, three-dimensional numerical simulation argumentation is carried out, the argumentation process is closely combined with goaf collapse feature analysis, and the stope structure parameters are finally determined. If only the top plate of the goaf collapses, anchor cable supports are added on the top plate, and the length of the anchor cables is closely combined with the collapse height of the top plate of the goaf. According to the method, the data of the goaf can be systematically analyzed and summarized, the caving reason of the goaf is determined, and the structural parameters of the stope are timely and accurately adjusted.

Description

Technical Field

[0001] The present invention relates to the field of metal mine mining, and particularly relates to a method for evaluating and optimizing stope structure parameters based on goaf big data. Background Art

[0002] In underground mining, after the stope is mined, more and more mines start to conduct three-dimensional space scanning on the goaf. Through three-dimensional scanning, the boundary of the goaf can be accurately determined, providing a boundary basis for the blasting of adjacent stope mining, and effectively reducing the loss and dilution of ore. With the development of modern high-precision scanning technology, three-dimensional scanning can accurately analyze the characteristics and causes of goaf caving, providing a basis for the evaluation and optimization of goaf structure parameters.

[0003] With the development of modern three-dimensional space scanning technology, the scanning efficiency of the goaf is getting higher and higher, and the accuracy is getting higher and higher, providing an accurate basis for goaf treatment, ore extraction, and optimization of stope structure parameters. At present, during the underground mine mining process, a large amount of goaf data has been accumulated. The analysis of the goaf often only focuses on the data analysis of a single goaf, lacking systematic analysis and summary. In addition, it is difficult to quickly analyze the cause of goaf caving through goaf data analysis. It is very necessary to invent a method for evaluating and optimizing stope structure parameters based on goaf big data for quickly diagnosing the cause of goaf caving and quickly adjusting the stope structure parameters. Summary of the Invention

[0004] One technical problem solved by the present invention is to invent a method for quickly diagnosing and evaluating the cause of goaf caving and realizing the adjustment of stope structure parameters with the progress of modern three-dimensional scanning technology.

[0005] The technical solution adopted by the present invention is: a method for evaluating and optimizing stope structure parameters based on goaf big data, comprising the following steps:

[0006] S1: Initially analyze the goaf big data model. Through the goaf model, the size of caving in each goaf can be visually seen, and it is analyzed whether there is caving in the goaf. The main positions of goaf caving include two types: one is roof caving; the other is the caving of the side wall ore pillar.

[0007] S2: Analyze the size of goaf collapse in the goaf big data. The collapse includes four types: the first type: no collapse; the second type: roof collapse; the third type: side collapse; the fourth type: through collapse of the roof and side wall.

[0008] S3: Record the stope structure data without collapse, and record parameters such as the length, width, and height of the stope.

[0009] S4: Analyze the caved stope using PointStudio software. Through the transparency analysis of the goaf, characteristics such as joint fissures in the goaf are analyzed, and combined with the mechanical properties and geological conditions of the ore and rock, determine the reasons for the collapse of the goaf.

[0010] S5: Evaluate the stability of the goaf. The evaluation content includes four categories: The first category: stable; the second category: basically stable; the third category: unstable; the fourth category: extremely unstable.

[0011] S6: Re-analyze the caved goaf to analyze whether there are common problems in the collapse. When there are common problems in the stope collapse, it indicates that corresponding measures need to be taken from this aspect to control the stope collapse; when the collapse of the goaf due to a certain reason is only an individual phenomenon, it indicates that the collapse event is an accidental event and no adjustment is required.

[0012] S7: Theoretically calculate and verify the safety of the roof and ore pillars: If the safety factors of the roof and ore pillars are consistent with the data analysis results of the goaf, it indicates that the stope structure parameters need to be optimized; if they are inconsistent with the goaf collapse phenomenon, it is necessary to return for re-analysis.

[0013] Safety factor of the roof:

[0014]

[0015] In the formula: n is the safety factor of the roof; t is the reduction coefficient, determined according to the rock conditions; Q is the average compressive strength of the ore and rock; RQD is the average RQD value of the ore and rock; a is the long radius of the horizontal elliptical cross-section of the caved rock mass; b is the short radius of the ellipse; R is the specific gravity of the ore and rock.

[0016] Considering the influence of joint development and blasting vibration of the ore and rock, when the safety factor of the roof exceeds 1.6, it indicates that the safety and stability of the roof are better; otherwise, the safety of the roof is poor and measures need to be taken to improve the safety of the roof.

[0017] Safety factor of the ore pillar:

[0018]

[0019] In the formula: n is the safety factor of the ore pillar; K is the strength of the ore pillar rock mass; W P is the width of the ore pillar; h is the height of the ore pillar; V is the volume of the ore pillar; a is a constant related to the rock; b is a constant related to the rock; L is the length of the ore pillar; d 1 is the span of the goaf; d 2 is the thickness of the roof ore and rock; r 岩 is the specific gravity of the rock; r 矿 is the specific gravity of the ore.

[0020] Considering the joint development of ore and rock and the influence of blasting vibration, when the safety factor of the ore pillar exceeds 1.6, it indicates that the safety and stability of the ore pillar are relatively good; on the contrary, the safety of the ore pillar is poor, and measures need to be taken to improve the safety of the roof;

[0021] S8: When the safety factors of both the roof and the ore pillar exceed the safety valve threshold, no optimization is required; when the roof does not reach the safety value and the ore pillar exceeds the safety valve threshold, it indicates that there is a collapse phenomenon in the roof, and only the roof needs to be strengthened; when neither the roof nor the ore pillar reaches the safety valve threshold, both the ore pillar and the roof need to adjust the stope structure parameters for optimization; when the roof exceeds the safety valve threshold and the ore pillar does not reach the safety valve threshold, it indicates that only the structural parameters of the ore pillar need to be optimized;

[0022] S9: The theoretical calculation of the ultimate exposure area of the stope, and the most extreme length and width suitable for the stope are calculated through the ultimate exposure area. The formula is where H is the thickness of the roof rock layer, and δ 最大拉应力 is the maximum tensile stress of the ore and rock; α 折减 is the reduction coefficient, which is determined according to the rock properties;

[0023] S10: Combining the stope structure parameters without collapse recorded in S3 and the comprehensive analysis of the ultimate exposure calculation, the stope structure parameters are initially determined; then, using three-dimensional numerical simulation software, three-dimensional element models of the original structure parameters and the optimized structure parameters are constructed, and the analysis of each index of the original structure parameters is closely combined with the shape of the goaf collapse; then, based on the original structure parameters, the optimization analysis of the stope result parameters is carried out to analyze the change trend of each index; when the index does not change significantly, it indicates that the optimized structure parameters are not reasonable, and the stope structure parameters are re-selected; until the index changes significantly, it indicates that the optimized structure parameters play a prominent role, the optimized stope structure parameters are reasonable, and the optimized parameters are determined.

[0024] As a further improvement of the present invention, in S2, the collapse of the roof and the sidewall ore pillars needs to consider the collapse thickness. From the perspective of mine support technology and influence range, the collapse of the roof and the sidewall within 5m has little impact on production. Therefore, it is defined that the influence of the collapse within 5m on the stability of the stope is negligible; the collapse of the roof and the sidewall ore pillars more than 5m has an impact on the stability of the stope; for the through-type collapse of the roof and the sidewall ore pillars, regardless of the size of the collapse, the safety risk is relatively large.

[0025] As a further improvement of the present invention, in step S8, when the roof has not reached the safety value and the ore pillar exceeds the safety valve value, it indicates that there is a phenomenon of roof collapse. Only the roof needs to be strengthened in support. The support plan for strengthening the roof is to add cable bolt support on the basis of bolt-mesh support: The length calculation factors of the cable bolt include: the maximum height of roof collapse in the goaf big data; the exposed length of the cable bolt, generally taken as 0.3 m; the anchorage length of the cable bolt, generally taken as 1 - 2 m; the length of the cable bolt is the sum of the three factors. The calculation of the row and column spacing of the cable bolts: According to the formula for the row and column spacing of the cable bolts calculate, where a is the row spacing of the cable bolts, which is related to the properties of the roof rock mass and the roof thickness; h l is the thickness of the lowest layer of the roof rock; σ t is the tensile strength of the roof rock; γ k is the average unit weight of the roof rock; h max is the loosening height of the roof; k l is the integrity coefficient of the roof rock mass;

[0026] Due to the reasons of the bar ore pillar in the drilling chamber, the calculation of some cable bolts needs to be adjusted. When the row spacing of two rows of cable bolts is relatively large, in order to improve the support effect, the cable bolts are constructed with a 2° deviation towards both sides of the bar ore pillar.

[0027] The beneficial effects of the present invention are as follows: First, there is a large amount of data in the goaf big data, and the accuracy of the stability analysis of the stope is high; through the transparent analysis of three-dimensional data, the reasons for the collapse and caving in the goaf can be intuitively analyzed; the combination of three-dimensional numerical simulation calculation and goaf data applies the theoretical analysis indexes to field practice, and the analyzed index data is more reliable and the optimized stope structure parameters are more reasonable. Brief Description of the Drawings

[0028] Figure 1 is the working flow chart of the present invention;

[0029] Figure 2 is the three-dimensional goaf data model to visually see the thickness of the data collapse and caving in the goaf;

[0030] Figure 3 is the data table recording the thickness and type of the collapse and caving of the roof and side wall ore pillars in the goaf;

[0031] Figure 4 is the classification diagram of the collapse types in the goaf;

[0032] Figure 5 is the identification diagram for identifying the reasons for the collapse of the transparent goaf model;

[0033] Figure 6 is the cable bolt support plan diagram of the roof;

[0034] Figure 7 is the data table of the percentage of the goafs with four collapse types in the total number of goafs. Detailed implementation mode

[0035] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation cases.

[0036] Taking the goaf big data model of a copper mine in Anhui as an example, analyze the stability of its stope structure parameters and the method for optimizing its stope structure parameters.

[0037] S1: Initially analyze the goaf big data model. Through the goaf model, the size of the collapse of the model can be visually seen through software. As Figure 2 shown, it can be visually seen the maximum thickness of the goaf collapse, analyze and record the thickness of the collapse of the roof and side wall pillars of the goaf.

[0038] S2: Classify the goafs. The classification includes four types: The first type: basically no collapse; the second type: roof collapse; the third type: side collapse; the fourth type: roof and side wall through collapse. Record the stope structure parameters and collapse conditions of each type of stope; the recorded data is as Figure 3 shown, and the category discrimination diagram of the goaf collapse is as Figure 4 shown;

[0039] S3: Record the stope structure data without collapse, and record parameters such as the length, width, and height of the stope.

[0040] S4: Use PointStudio software to open the goaf data model, transparently analyze features such as joint fissures in the goaf, and determine the cause of the goaf collapse; for example, as Figure 5 shown, the rock at the collapse location of the T305 stope from -650 to -770m is irregular and the rock structure is loose, indicating that the rock in this area is broken. Therefore, the rock mass structure is the main cause of the collapse of this stope.

[0041] S5: Evaluate the stability of the goaf. The evaluation content includes four categories: The first category: stable; the second category: basically stable; the third category: unstable; the fourth category: extremely unstable. The evaluation of each goaf is mainly based on the percentage of the collapsed goafs in the total number of goafs. Through the analysis of the goaf data, the proportion of the collapsed stopes is 73%, indicating that the stability of this goaf is of the extremely unstable type;

[0042] S6: Re-analyze the collapsed goafs. There are common problems in the collapse situation. For example, stopes with a height of 120m generally have collapse phenomena; the probability of roof collapse in stopes with a width of 30m is 50%, indicating that corresponding measures need to be taken to control the collapse of the stopes; for example, for a stope with a height of 55m and a width of 24m, the stope collapse is an individual phenomenon, indicating that the collapse event is an accidental event and no adjustment is required;

[0043] S7: Theoretical calculation to verify the safety of the roof and ore pillars: Through theoretical calculations using the formulas for the roof safety factor and ore pillar safety factor, it is analyzed that when the stope height is 120 m, the safety factors of the ore pillars are all lower than the safety valve thresholds; when the stope width is 30 m, the safety factor of the roof is lower than the safety valve threshold. Therefore, the stope structure parameters with a stope height of 120 m and stope widths of 30 m and 24 m are optimized; for the stope roofs with stope heights of 65 m and 55 m and a width of 30 m, enhanced support is provided. Table 1 is a data table of the stope structure parameters and the corresponding roof safety factors and ore pillar safety factors;

[0044] Table 1

[0045]

[0046]

[0047] S8: Through theoretical formula calculations, the limit exposed area of the stope is obtained as 1950 m 2 , and in this mine, panel mining is carried out, and the stope lengths in the panel are all 80 m. Therefore, it is calculated that the stope width does not exceed 24 m. Combining with the caving situation of the goaf data, the optimized stope structure parameters are preliminarily determined, and the structure parameters of all stopes are optimized to: 80*20*65 or 80*20*55;

[0048] S9: Using three-dimensional numerical simulation software, three-dimensional element models of the original structure parameters and the optimized structure parameters are constructed, and the analysis of each index of the original structure parameters is closely combined with the caving shape of the goaf; then, on the basis of the original structure parameters, an optimization analysis of the stope result parameters is carried out to analyze the change trend of each index; when the index does not change significantly, it indicates that the optimized structure parameters are not reasonable, and the stope structure parameters are re-primarily selected; until the index changes significantly, it indicates that the optimized structure parameters play a prominent role and the optimized stope structure parameters are more reasonable, and the optimized parameters are determined. Table 2 is a data table of the stope parameters and the corresponding index data;

[0049] Table 2

[0050]

[0051] After demonstration, when the stope width is reduced from 30 m to 20 m for the optimized stope structure parameters, the tensile strength of the roof is significantly reduced, with a reduction amplitude of 72.6%, and the displacement value is reduced by 62%; when the stope height is adjusted to 65 m, the tensile stress on the side wall is reduced by 41%, and the displacement value is reduced by 53%. Theoretically, this scheme has a good effect in improving the stability of the stope.

[0052] S10: In step five, the probability of roof caving in a stope with a width of 30 m is 50%, indicating that corresponding measures need to be taken to control the roof caving in the stope, that is, to strengthen the support for the roof. The strengthened roof support plan is to add cable bolt support on the basis of bolting with wire mesh support: The length calculation factors of the cable bolts include: the maximum height of roof caving in the goaf big data, which is taken as 13 m according to the goaf big data; the exposed length of the cable bolt, generally taken as 0.3 m; the anchorage length of the cable bolt, generally taken as 1 - 2 m; the length of the cable bolt is the sum of the three factors, that is, the length of the cable bolt is 14.5 m; the row and column spacing of the cable bolts is 3 m obtained according to the formula. Due to the reasons of the bar pillar in the rock drilling chamber, some cable bolt calculations need to be adjusted. When the row spacing of two rows of cable bolts is relatively large, in order to improve the support effect, the cable bolts are constructed 2° towards both sides of the bar pillar. The support plan is as Figure 6 shown;

[0053] After the application of the optimized stope structure parameters and support plan, through the three-dimensional scanning of the goaf, no obvious caving phenomenon is found in the goaf.

[0054] Those skilled in the art should be aware that the protection scope of the present invention is not limited to the above embodiments, and various permutations, combinations and transformations can also be carried out on the basis of the above embodiments. Without departing from the spirit of the present invention, all transformations made to the present invention fall within the protection scope of the present invention.

Claims

1. A method for evaluating and optimizing stope structure parameters based on goaf big data, characterized in that: The following steps are involved: S1: Preliminary analysis of the goaf big data model. Through the goaf model, the size of each goaf collapse can be intuitively seen, and the goaf collapse can be analyzed. There are two main types of goaf collapse locations: one is roof collapse; the other is side wall pillar collapse; S2: Analyze the size of goaf collapse in goaf big data. The collapse includes four types: Category 1: no collapse; The second category: roof collapse; the third category: side collapse; Category 4: The roof and side walls collapse through; S3: Record the structural data of the stope without collapse, and record the length, width, height and other parameters of the stope; S4: The collapsed mining area is analyzed using PointStudio software. The characteristics of the goaf such as joints and fissures are analyzed by making the goaf transparent. The cause of the goaf collapse is determined by combining the mechanical properties of the ore and rock and geological conditions. S5: Evaluate the stability of the goaf, which includes four categories: Category 1: stability; Category 2: basically stable; Category 3: unstable; Category 4: Extremely unstable; S6: Re-analyze the collapsed goaf to analyze whether there are common problems. If there are common problems in the goaf, it indicates that corresponding measures need to be taken from this aspect to control the goaf collapse; if the goaf collapse is only an individual phenomenon due to a certain reason, it indicates that the collapse is an accidental event and no adjustment is needed; S7: Theoretical calculation verifies the safety of the roof and pillars: If the safety factor of the roof and pillars is consistent with the analysis results of the goaf data, it indicates that the stope structure parameters need to be optimized; if it is inconsistent with the goaf collapse phenomenon, it is necessary to return and re-analyze; Safety factor of top plate: Where: n is the safety factor of the roof; t is the reduction factor, which is determined according to the rock conditions; Q is the average compressive strength of the ore rock; RQD is the average RQD value of the ore rock; a is the long radius of the horizontal elliptical section of the caving rock mass; b is the short radius of the ellipse; R is the specific gravity of the ore rock; Considering the joint development of the ore rock and the influence of blasting vibration, when the roof safety factor exceeds 1.6, it indicates that the roof safety and stability are good; otherwise, the roof safety is poor and measures need to be taken to improve the roof safety; Safety factor of the pillar: Where: n is the safety factor of the pillar; K is the strength of the pillar rock mass; W P is the width of the pillar; h is the height of the pillar; V is the volume of the pillar; a is a constant related to rock; b is a constant related to rock; L is the length of the pillar; d1 is the span of the goaf; d2 is the thickness of the roof ore rock; r 岩 is the specific gravity of rock; r 矿 is the specific gravity of the ore; Considering the joint development of the ore rock and the influence of blasting vibration, when the safety factor of the pillar exceeds 1.6, it indicates that the pillar has good safety and stability; otherwise, the pillar has poor safety and measures need to be taken to improve the safety of the roof; S8: When the safety factors of the roof and the pillars exceed the safety threshold, no optimization is required; when the roof has not reached the safety threshold and the pillars exceed the safety threshold, it indicates that the roof has collapsed and only the roof needs to be supported; when the roof and the pillars have not reached the safety threshold, the pillars and the roof need to adjust the mining field structural parameters for optimization; when the roof exceeds the safety threshold and the pillars do not reach the safety threshold, it indicates that only the structural parameters of the pillars need to be optimized; S9: Theoretically calculate the maximum exposure area of ​​the stope, and calculate the maximum length and width suitable for the stope through the maximum exposure area. The formula is: Where H is the thickness of the roof rock layer, δ 最大拉应力 is the maximum tensile stress of the ore rock; α 折减 is the reduction factor, which is determined according to the rock properties; S10: Combine the stope structure parameters without collapse recorded in S3 and the calculation and comprehensive analysis of the limit exposure to preliminarily determine the stope structure parameters; then use the three-dimensional numerical simulation software to construct a three-dimensional unit model of the original structure parameters and the optimized structure parameters, and the analysis of each index of the original structure parameters is closely combined with the morphology of the collapse of the goaf; Then, based on the original structural parameters, the stope result parameter optimization analysis is carried out to analyze the change trend of each index; when the index does not change significantly, it indicates that the optimized structural parameters are not reasonable, and the stope structural parameters are re-selected; Until the indicators change significantly, it shows that the optimized structural parameters have played a prominent role, the optimized stope structural parameters are reasonable, and the optimized parameters are determined.

2. The method for evaluating and optimizing stope structure parameters based on goaf big data according to claim 1, characterized in that: In S2, the collapse of the roof and side pillars needs to consider the thickness of the collapse. According to the mine support technology and the impact range, the collapse of the roof and side pillars within 5m has little impact on production. For this reason, it is defined that the impact of collapse within 5m on the stability of the mining area is negligible; the collapse of the roof and side pillars more than 5m has an impact on the stability of the mining area; the collapse of the roof and side pillars through the type, regardless of the size of the collapse, has a greater safety risk.

3. The method for evaluating and optimizing stope structure parameters based on goaf big data according to claim 1, characterized in that: In the above S8, when the roof has not reached the safety value and the pillar exceeds the safety threshold, it indicates that the roof has collapsed. It is only necessary to strengthen the support of the roof. The support scheme for strengthening the roof is to add anchor cable support on the basis of anchor net support: the length calculation factors of the anchor cable include: the maximum height of the roof collapse in the goaf big data; the exposed length of the anchor cable, which is generally 0.3m; the anchor cable anchoring length, which is generally 1-2m; the length of the anchor cable is the sum of the three factors, and the spacing between anchor cables is calculated: according to the spacing formula between anchor cables Calculation, where a is the anchor cable spacing, which is related to the top rock mass properties and top plate thickness; h l is the thickness of the lowest rock layer of the roof; σ t is the tensile strength of the roof rock; k is the average bulk density of the roof rock; h max k is the loose height of the top plate; l is the roof rock mass integrity coefficient; Due to the strip-shaped pillars in the rock drilling chamber, the calculation of some anchor cables needs to be adjusted. When the spacing between two rows of anchor cables is relatively large, in order to improve the support effect, the anchor cables are constructed 2° to both sides of the strip-shaped pillars.

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