Dangerous area-based combined vertical artificial column system setting method

Abstract

The invention belongs to the technical field of island construction engineering, deep-sea mining and metal excavation stability, and discloses a method for arranging a combined vertical artificial column system based on a dangerous area. According to the method, the three-level artificial columns are scientifically reserved for the horizontal dangerous area in combination with calculation of field data. According to the scheme, the artificial columns which are higher in bearing capacity and better in stability compared with natural columns are adopted, and reasonable calculation and arrangement of the reserved size, the reserved thickness and the reserved position are conducted on the combined vertical artificial column system based on all excavation horizontal dangerous areas in the excavation process; the artificial column system has a supporting effect on surrounding rocks on different excavation levels and different vertical sections from the three-dimensional whole of a mining area. And the artificial columns at all levels cooperate to jointly bear the load effect, so that the stability of the surrounding rock of the stope is improved, and the safety of workers and operation equipment is more favorably guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of underground excavation, relates to an arrangement mode of artificial columns in an underground excavation process, and specifically relates to a method for retaining a combined vertical artificial column system based on a dangerous area. Background Art

[0002] Artificial pillars refer to artificial concrete pillars with higher strength and stability that are used to replace rocks or ore bodies during the excavation process in order to protect the safety of underground personnel and equipment. They serve to support the roof and maintain the stability of the surrounding rock of the goaf.

[0003] When mining in a mine room, the stability of the roof and floor of the mine is extremely critical. After the mine room is excavated, the unloading effect caused by the excavation of the original rock will cause the surrounding rock of the goaf to deform. With the mining of ore resources in each horizontal stratum, the goaf gradually increases, the stress of the surrounding rock is released, the roof of the goaf will produce a downward settlement displacement, and the rock mass of the bottom of the goaf will produce an upward uplift displacement, posing a great threat to the safety of workers and equipment. In traditional mining methods, the method of reserving natural pillars is used to maintain the stress balance of the goaf. Since natural pillars belong to the anisotropic original rock, the bearing capacity of the reserved natural pillars is poor, and they are greatly affected by the vibration of mining blasting, and their stability and reliability are not high.

[0004] In previous excavation processes, the plans for retaining pillars often adopted the analogy method or the empirical method. The key positions of the pillars were not prominent enough, the form and size of the pillars were unreasonable, and the basis was insufficient.

[0005] At the same time, most of the existing technologies use horizontal isolation pillars, which are set in a single position and have a relatively single level of support for the surrounding rock. When the ore bodies at different levels are subsequently excavated, the surrounding rock support effect and stability are poor, and it is easy to cause a waste of ore resources. Correspondingly, the unreasonable position of the pillar setting area will cause the pillar to fail to play its due role and fail to play a good role in supporting the roof; if the size of the pillar is too large, the ore resource recovery rate will be low, wasting resources; if the size is too small, the safety of the staff and operating equipment cannot be guaranteed.

[0006] If there is a technology that can reasonably arrange a combined vertical isolation artificial column system from a three-dimensional perspective, it can provide effective support to the surrounding rock when excavating ore bodies at different levels. At the same time, it can effectively solve the problems of poor bearing capacity, low stability and low ore resource recovery rate of natural pillars. Summary of the invention

[0007] In view of the shortcomings of the above-mentioned prior art, the present invention proposes a method for setting up a combined vertical artificial column system in dangerous areas. The method focuses on arranging artificial columns in the dangerous areas of the entire mining area, and on the basis of ensuring the safety of operators and operating equipment, improves the recovery rate of ore resources and provides a scientific reference for safe and economic mining of mines.

[0008] A method for installing a combined vertical artificial column system in a dangerous area according to the present invention specifically comprises the following steps:

[0009] Step 1: Determine the dangerous areas at each excavation level during the excavation process;

[0010] Step 2: Arrange the first-level artificial column: Arrange the first-level artificial column in the center of the dangerous area to bear the main load of the top plate;

[0011] Step 3: Arrange three-level artificial columns: Arrange three-level artificial columns at the edge of the dangerous area to expand the influence range of the artificial column system;

[0012] Step 4: Arrange the secondary artificial columns: Arrange the secondary artificial columns on the line connecting the center points of the primary artificial columns and the tertiary artificial columns, cooperate with the primary artificial columns to bear the main load, and cooperate with the tertiary artificial columns to make the artificial column system load more uniform and more stable;

[0013] In the present invention, the dangerous area described in step 1 is the rock fracture zone, fault zone and settlement and high stress area identified during the excavation process through preliminary mining area geological survey or mine monitoring system or excavation simulation.

[0014] In the present invention, the dangerous area defined in step 1 should be a square to ensure the overall stability of the artificial column system.

[0015] In the present invention, after determining each excavation level danger zone, different excavation level danger zones in different excavation stages are connected to finally form a three-dimensional danger zone of the entire mining area.

[0016] In the present invention, the center point of the dangerous area described in step 1 should be the place where the surrounding rock conditions are the worst and where settlement and stress peaks occur during the excavation process, including but not limited to.

[0017] In the present invention, the three-level artificial columns in step 3 should be set at the edge of the danger zone. Preferably, the three-level artificial columns are set at the four corners of the edge of the square danger zone.

[0018] In the present invention, the secondary artificial column in step 4 should be set between the midpoints of the primary artificial column and the tertiary artificial column. Preferably, the secondary artificial column is set at the midpoint of the line connecting the midpoints of the primary artificial column and the tertiary artificial column.

[0019] In the present invention, the size of the first-level artificial column in step 2-3 is the largest, the size of the second-level artificial column is the second largest, and the size of the third-level artificial column is the smallest.

[0020] In the present invention, the numbers of the first-level artificial columns, the second-level artificial columns and the third-level artificial columns in step 2-3 are n1=1, n2=4 and n3=4 respectively.

[0021] In the present invention, step 2-3 also includes the step of determining the size of artificial columns at each level. The size should be determined by the stress borne by the artificial columns, specifically:

[0022] S1, according to the designated dangerous area, determine the area of ​​the dangerous area, calculate the bearing capacity of the dangerous area on the artificial column system. The specific calculation formula is:

[0023] σ z =γ×H (1)

[0024] F z =σ z ×A1 (2)

[0025] Where: z is the total vertical stress borne by the artificial column, in KN / m 2 ; γ is the weight of the upper rock layer, unit is KN / m 3 ; H is the height of the overlying rock layer on the artificial column, in m; F z is the vertical force that the artificial column system needs to bear, in KN; A1 is the area of ​​the designated dangerous area, in m 2 .

[0026] S2, calculate the minimum side length of artificial columns at all levels of the artificial column system. The cross section of the artificial column is a square. The specific calculation formula is:

[0027]

[0028] Where: i = 1, 2, 3 represents the serial number of artificial columns at each level, λ i F is the safety factor of artificial columns at all levels of the artificial column system, and the value range should be 1.2 to 2.5; z is the vertical force that the artificial column system needs to bear, in KN; n i The number of artificial columns reserved for each level; k i is the reduction factor in the actual application of the artificial column system, and its value range should be 0.6 to 0.8; σ c It is the design value of uniaxial compressive strength of artificial columns at all levels in the artificial column system.

[0029] It should be noted that in order to ensure the overall stability of the artificial column system during actual application, the bearing capacity of each level of artificial columns in the present invention must independently meet the requirements of the total vertical stress. At the same time, the maximum uniaxial compressive strength of each level of artificial columns is the same.

[0030] In the present invention, the minimum cross-sectional dimensions of the first-level artificial column, the second-level artificial column and the third-level artificial column can be obtained by repeatedly implementing the calculation steps S1 and S2.

[0031] In the present invention, in the actual design of the primary artificial column, the secondary artificial column and the tertiary artificial column described in step 2-3, in addition to the mechanical strength, the slenderness ratio of the artificial column should also be considered, and the slenderness ratio should be less than 10.

[0032] In the present invention, the minimum thickness of the first-level artificial column, the second-level artificial column and the third-level artificial column described in step 2-3 along the vertical direction of the ore body is 25m.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The present invention determines the three-dimensional dangerous area of ​​the entire mining area according to the dangerous area determined by each excavation level during the excavation process, and then connects the dangerous areas of the excavation levels at different mining stages. Based on this three-dimensional dangerous area, the combined vertical artificial columns are arranged, and the first-level artificial column is arranged at the center of the dangerous area of ​​the excavation level in the same mining stage, and then the third-level artificial column is arranged at the edge of the dangerous area, and finally the second-level artificial column is arranged on the line connecting the center points of the first-level artificial column and the third-level artificial column. Artificial columns at all levels can provide effective support to the surrounding rock at each mining stage and each mining level, and artificial columns at all levels cooperate with each other to jointly bear the load of the overlying rock strata and maintain the stability of the surrounding rock in the mining area.

[0035] 2. The method of replacing the pillars with artificial pillars in the present invention has better bearing capacity and stability than the scheme of reserving natural pillars in the prior art. The reasonable arrangement of the artificial pillar system is more conducive to ensuring the safety of underground workers and operating equipment, further improving the stability of the surrounding rock, and further improving the rock mechanics conditions in the dangerous area. At the same time, the method of using combined vertical artificial pillars provides more effective support for the three-dimensional dangerous area of ​​the entire mining area, effectively reduces the size of the artificial pillars, improves the recovery rate of ore resources, and solves the problem of waste caused by the inability to recover ore resources.

[0036] 3. In the present invention, artificial columns are accurately arranged in an orderly and regular manner based on the three-dimensional danger zone, and the size of the artificial columns is reasonably and accurately calculated, so that the combined artificial column system plays a more effective role in maintaining the stability of the surrounding rock at each stage of excavation, each mining level, and key areas. Compared with the random arrangement of each pillar according to the analogy method or the empirical method in the prior art, the necessity and effectiveness of the artificial column position are ensured, and the rationality of the artificial column size is ensured, that is, the surrounding rock instability will not occur due to the small size of the artificial column, and the filling cost will not be too high due to the large size of the artificial column. The overall stability of the long-term operation of the entire artificial column system is ensured, thereby fully guaranteeing the safe, economical and efficient mining of the excavation. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the planar arrangement of the pillars in the filling mining method in the prior art;

[0038] Figure 2 Schematic diagram of the layout of the artificial column system based on the dangerous area in the present invention

[0039] Figure 3 for Figure 2 Schematic diagram of the AA section;

[0040] Figure 4 for Figure 2 Schematic diagram of the middle BB section;

[0041] Figure 5 for Figure 2 Schematic diagram of the middle CC section;

[0042] Figure 6 for Figure 2 Schematic diagram of the middle DD section;

[0043] Figure 7 It is the dangerous area during the excavation process defined in the present invention;

[0044] Figure 8 It is a primary pillar arrangement diagram based on dangerous areas in the present invention;

[0045] Fig. 9 It is the layout diagram of the secondary pillars based on the dangerous area in the present invention;

[0046] Fig.10 It is the layout diagram of three-level pillars based on dangerous areas in the present invention;

[0047] Fig.11 This is a flow chart for the arrangement of combined vertical artificial columns in the present invention.

[0048] In the figure: 1. Surrounding rock of the upper wall of the mining area; 2. Ore body to be mined; 3. Determination of dangerous areas; 4. Third-level artificial pillars; 5. First-level artificial pillars; 6. Second-level artificial pillars; 7. Surrounding rock of the lower wall of the mining area; 8. Excavation layers in the vertical direction of the ore body to be mined DETAILED DESCRIPTION

[0049] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0050] Embodiment 1:

[0051] like Figures 1 to 11 As shown, the present invention provides a method for installing a combined vertical artificial column system in a dangerous area, and the method includes the following steps:

[0052] Step 1: Delineate the dangerous areas at each excavation level during the excavation process;

[0053] Step 2: Arrange the first-level artificial column: Arrange the first-level artificial column in the center of the dangerous area;

[0054] Step 3: Arrange three-level artificial columns: Arrange three-level artificial columns at the edge of the danger zone;

[0055] Step 4: Arrange the secondary artificial columns: Arrange the secondary artificial columns on the line connecting the center points of the primary artificial columns and the tertiary artificial columns.

[0056] In this implementation example, the dangerous area in step 1 is an area with large subsidence identified by combining the previous mining area geological survey with the mine monitoring method;

[0057] In this implementation example, the danger zone defined in step 1 should be a square to ensure the overall stability of the artificial column system;

[0058] In this embodiment, after determining each horizontal dangerous area of ​​excavation, different horizontal dangerous areas of excavation are connected to finally form a three-dimensional dangerous area of ​​the entire mining area. The vertical artificial column system of each level of the vertical section of the three-dimensional dangerous area is arranged as follows: Figure 3-Figure 6 shown.

[0059] In this implementation example, the center point of the danger zone described in step 1 should be the peak point of settlement generated during the excavation process.

[0060] In this implementation example, the first-level artificial column in step 2 is set at the center of the horizontal dangerous area of ​​the excavation;

[0061] In this implementation example, the three-level artificial columns in step 3 are set at the four corners of the edge of the square danger zone.

[0062] In this embodiment, in step 4, the secondary artificial column is left at the midpoint of the line connecting the midpoints of the primary artificial column and the tertiary artificial column.

[0063] In this embodiment, the size of the first-level artificial column in step 2-3 is the largest, the size of the second-level artificial column is the second largest, and the size of the third-level artificial column is the smallest.

[0064] In this embodiment, the numbers of the first-level artificial columns, the second-level artificial columns and the third-level artificial columns in step 2-3 are n1=1, n2=4 and n3=4 respectively.

[0065] In this implementation example, step 2-3 also includes the step of determining the size of artificial columns at each level. The size should be determined by the stress borne by the artificial columns, specifically:

[0066] S1, based on the designated dangerous area, determine the area of ​​the dangerous area, and calculate the bearing capacity imposed by the dangerous area on the artificial column system, where:

[0067] σ z =γ×H

[0068] F z =σ z ×A1

[0069] Where: z is the total vertical stress borne by the artificial column, in KN / m 2 ; γ is the weight of the upper rock layer, unit is KN / m 3 ; H is the height of the overlying rock layer on the artificial column, in m; F is the vertical force that the artificial column system needs to bear, in KN; A1 is the area of ​​the designated dangerous area, in m 2 .

[0070] S2, calculate the minimum side length of artificial columns at all levels of the artificial column system. The cross section of the artificial column is a square. The calculation formula is:

[0071]

[0072] Where: i F is the safety factor of artificial columns at all levels of the artificial column system, and the value range should be 1.2 to 2.5; z is the vertical force that the artificial column system needs to bear, in KN; n i The number of artificial columns reserved for each level; k i is the reduction factor in the actual application of the artificial column system, and its value range should be 0.6 to 0.8; σ cIt is the design value of uniaxial compressive strength of artificial columns at all levels in the artificial column system.

[0073] It should be noted that in order to ensure the overall stability of the artificial column system during actual application, the bearing capacity of each level of artificial columns in the present invention must independently meet the requirements of the total vertical stress. At the same time, the maximum uniaxial compressive strength of each level of artificial columns is the same.

[0074] In the present invention, the minimum cross-sectional dimensions of the first-level artificial column, the second-level artificial column and the third-level artificial column can be obtained by repeatedly implementing the calculation steps S1 and S2.

[0075] Embodiment 2:

[0076] A method for arranging an artificial column system in a dangerous area of ​​a mine, the method comprising the following steps:

[0077] Step 1: Delineate the dangerous area during excavation and determine the area of ​​the dangerous area. The dangerous area is determined to be a square area with a side length of 40m and an area of ​​1600m 2 ,like Figure 7 As shown;

[0078] Among them, in this embodiment, a square danger zone is delineated with the settlement peak point in the real-time monitoring of the mine as the center.

[0079] Embodiment 3:

[0080] Step 2: Arrange the first-level artificial column: Arrange the first-level artificial column in the center of the dangerous area. The number of first-level artificial columns is 1. Figure 8 As shown;

[0081] Embodiment 4:

[0082] Step 3: Arrange three-level artificial columns: Arrange three-level artificial columns at the edge of the danger zone;

[0083] Among them, the third-level artificial columns are arranged at the four corners of the dangerous area, and the number of third-level artificial columns is 4. Fig.10 As shown;

[0084] Embodiment 5:

[0085] Step 4: Arrange the secondary artificial columns: Arrange the secondary artificial columns on the line connecting the center points of the primary artificial columns and the tertiary artificial columns. The number of secondary artificial columns is 4. Fig. 9 As shown;

[0086] Among them, the secondary artificial column is arranged at the midpoint of the line connecting the center points of the primary artificial column and the tertiary artificial column.

[0087] Embodiment 6:

[0088] According to the designated dangerous area, the area of ​​the dangerous area is determined, and the bearing capacity imposed by the dangerous area on the primary artificial column system is calculated, where:

[0089] σ z =γ×H=25.4×50=1270KN / m 2

[0090] F z =σ z ×A1=1270×1600=2.032×10 6 KN

[0091] Among them, γ is the weight of the upper rock layer, and its value is 25.4KN / m 3 ; H is the height of the overlying rock layer on the artificial column, the value is 50m; A1 is the area of ​​the designated dangerous area, the value is 1600m 2

[0092]

[0093] Among them, λ1 is the safety factor of the first-level artificial column, which is 2.0; n1 is the number of first-level artificial columns, which is 1; k1 is the reduction coefficient of the first-level artificial column in actual application, which is 0.8; σ c It is the design value of uniaxial compressive strength of first-level artificial column, which is 10MPa.

[0094] According to the calculation results of Example 6, the minimum cross-sectional side length of the first-level artificial column is 22.539m, and B1 = 23m. Preferably, the thickness of the first-level artificial column along the vertical direction of the ore body is 50m.

[0095] Embodiment 7:

[0096] According to the designated dangerous area, the area of ​​the dangerous area is determined, and the bearing capacity imposed by the dangerous area on the three-level artificial column system is calculated, where:

[0097] σ z =γ×H=25.4×50=1270KN / m 2

[0098] F z =σ z ×A1=1270×1600=2.032×10 6 KN

[0099] Among them, γ is the weight of the upper rock layer, and its value is 25.4KN / m 3 ; H is the height of the overlying rock layer on the artificial column, the value is 50m; A1 is the area of ​​the designated dangerous area, the value is 1600m 2

[0100]

[0101] Among them, λ3 is the safety factor of the third-level artificial column, which is 1.2; n3 is the number of third-level artificial columns, which is 4; k3 is the reduction coefficient in the actual application of the third-level artificial column, which is 0.8; σ c The uniaxial compressive strength design value of the third-level artificial column is 10MPa. Preferably, the thickness of the first-level artificial column along the vertical direction of the ore body is 25m.

[0102] According to the calculation results of Example 7, the minimum cross-sectional side length of the first-level artificial column is 8.729m, and B3=9m is taken.

[0103] Embodiment 8:

[0104] According to the designated dangerous area, the area of ​​the dangerous area is determined, and the bearing capacity imposed by the dangerous area on the secondary artificial column system is calculated, where:

[0105] σ z =γ×H=25.4×50=1270KN / m 2

[0106] F z =σ z ×A1=1270×1600=2.032×10 6 KN

[0107] Among them, γ is the weight of the upper rock layer, and its value is 25.4KN / m 3 ; H is the height of the overlying rock layer on the artificial column, the value is 50m; A1 is the area of ​​the designated dangerous area, the value is 1600m 2

[0108]

[0109] Among them, λ2 is the safety factor of the third-level artificial column, which is 1.8; n2 is the number of second-level artificial columns, which is 4; k2 is the reduction coefficient in the actual application of the second-level artificial column, which is 0.8; σ c It is the design value of uniaxial compressive strength of secondary artificial column, which is 10MPa.

[0110] According to the calculation results of Example 8, the minimum cross-sectional side length of the first-level artificial column is 10.691 m, and B2 = 11 m. Preferably, the thickness of the first-level artificial column along the vertical direction of the ore body is 30 m.

[0111] The above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for installing a combined vertical artificial column system in a dangerous area, the method comprising the following steps: Step 1: Determine the dangerous areas at each excavation level during the excavation process; Step 2: Arrange the first-level artificial column: Arrange the first-level artificial column in the center of the dangerous area to bear the main load of the top plate; Step 3: Arrange three-level artificial columns: Arrange three-level artificial columns at the edge of the dangerous area to expand the influence range of the artificial column system; Step 4: Arrange the secondary artificial columns: Arrange the secondary artificial columns on the line connecting the center points of the primary artificial columns and the tertiary artificial columns. The secondary artificial columns cooperate with the primary artificial columns and the tertiary artificial columns to bear the load.

2. A method for installing a combined vertical artificial column system in a dangerous area according to claim 1, characterized in that: The dangerous area in step 1 is the rock fracture zone, fault zone and settlement and stress-intensive area existing in the excavation process identified by the previous mining area geological survey or mine monitoring system or excavation simulation, and the dangerous area is set to a square.

3. A method for installing a combined vertical artificial column system in a dangerous area according to claim 2, characterized in that: After determining the dangerous areas of each excavation level, the different dangerous areas of the excavation levels in different excavation stages are connected to form a three-dimensional dangerous area of ​​the entire mining area.

4. The method for installing a combined vertical artificial column system in a dangerous area according to claim 1 is characterized in that: The center of the dangerous area in step 2 should be the place where the surrounding rock conditions are the worst, where settlement occurs, or where the stress peak occurs during the excavation process.

5. The method for installing a combined vertical artificial column system in a dangerous area according to claim 1 is characterized in that: The three-level artificial columns described in step 3 should be set at the four corners of the edge of the danger zone.

6. The method for installing a combined vertical artificial column system in a dangerous area according to claim 1 is characterized in that: The first-level artificial columns, second-level artificial columns and third-level artificial columns described in the steps have a minimum thickness of 25m along the vertical direction of the ore body; the first-level artificial columns described in the steps have the largest size, the second-level artificial columns have the second largest size, and the third-level artificial columns have the smallest size.

7. The method for installing a combined vertical artificial column system in a dangerous area according to claim 1 is characterized in that: In the step, the number of first-level artificial columns is n1=1, the number of second-level artificial columns is n2=4, and the number of third-level artificial columns is n3=4.

8. The method for installing a combined vertical artificial column system in a dangerous area according to claim 1 is characterized in that: The sizes of artificial columns at each level described in the steps should be determined by the stress borne by the artificial columns. The specific calculation method is: S1, according to the designated dangerous area, determine the area of ​​the dangerous area, calculate the bearing capacity of the dangerous area on the artificial column system. The specific calculation formula is: s z =γ×H (1) F z =s z ×A1 (2) Where: z is the total vertical stress borne by the artificial column, in KN / m 2 ; γ is the weight of the upper rock layer, unit is KN / m 3 ; H is the height of the overlying rock layer on the artificial column, in m; F z is the vertical force that the artificial column system needs to bear, in KN; A1 is the area of ​​the designated dangerous area, in m 2 ; S2, calculate the minimum side length of artificial columns at all levels of the artificial column system. The cross section of the artificial column is a square. The specific calculation formula is: Where: i = 1, 2, 3 represents the serial number of artificial columns at each level, λ i The safety factor of artificial columns at all levels of the artificial column system should range from 1.2 to 2.5; n i The number of artificial columns reserved for each level; k i is the reduction factor in the actual application of the artificial column system, and its value range should be 0.6 to 0.8; σ c It is the design value of uniaxial compressive strength of artificial columns at all levels of the artificial column system; the safety factor λ1 of the first-level artificial column is the largest, the safety factor λ2 of the second-level artificial column is the second, and the safety factor λ3 of the third-level artificial column is the smallest.

9. The method for installing a combined vertical artificial column system in a dangerous area according to claim 1 is characterized in that: The secondary artificial column is set at the midpoint of the line connecting the midpoints of the primary artificial column and the tertiary artificial column.

10. The method for installing a combined vertical artificial column system in a dangerous area according to claim 1, characterized in that: The minimum thickness of the first-level artificial columns, second-level artificial columns and third-level artificial columns along the vertical direction of the ore body is 25m, and the slenderness ratio coefficient of the artificial columns in actual design is less than 10.

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