Support column setting quantity calculation method and mining method based on large section roof control

Abstract

The application provides a support column setting quantity calculation method and a mining method based on large-section roof control, wherein the calculation method is used to determine a target quantity of support columns required to be arranged in a mined-out space during ore body mining, and comprises the following steps: calculating a basic support force required by the mined-out space based on roof surrounding rock mechanical parameters, buried depth and space geometric parameters of the mined-out space; determining a limit bearing capacity of a single support column; and determining the target quantity based on the basic support force and the limit bearing capacity. The support column setting quantity calculation method and the mining method based on large-section roof control make the determined target quantity of support columns more scientific and reasonable, avoid excessive or insufficient setting quantity of support columns while ensuring the safety of roof support, thereby reducing mining safety hazards and improving work efficiency.

Description

Technical Field

[0001] This application relates to the field of mining technology, and in particular to a method for calculating the number of support pillars and a mining method based on large-section roof control. Background Technology

[0002] During the mining of underground ore bodies, as the ore body is gradually extracted, a certain range of goaf space is formed. To ensure the safety of mining operations, it is usually necessary to support the exposed roof of the goaf space. One support method is to install additional support columns. However, the number of support columns is determined by on-site personnel based on historical experience such as operational experience and construction habits, lacking a scientific and reasonable calculation method. When the number of support columns is insufficient, it can easily lead to safety problems and pose safety hazards. Summary of the Invention

[0003] In view of this, the purpose of this application is to propose a method for calculating the number of support pillars and a mining method based on large-section roof control.

[0004] To achieve the above objectives, this application provides a method for calculating the number of support pillars required during ore body mining, for determining the target number of support pillars to be installed in the goaf. The method includes:

[0005] Based on the mechanical parameters, burial depth, and spatial geometric parameters of the roof surrounding rock of the goaf, the required foundation support force for the goaf is calculated. Determine the ultimate bearing capacity of a single support column; The target quantity is determined based on the basic support force and the ultimate bearing capacity.

[0006] Optionally, the mechanical parameters of the roof surrounding rock include the roof surrounding rock density, the roof surrounding rock mass cohesion, and the roof surrounding rock mass internal friction angle; the spatial geometric parameters of the goaf include the cross-sectional width, mining height, and mining depth. The required foundation support force for the goaf is calculated based on the mechanical parameters, burial depth, and spatial geometric parameters of the surrounding rock of the goaf, including: Based on the cross-sectional width and the mining height, the excavation radius of the goaf is determined; Based on the density of the surrounding rock of the roof and the burial depth, the vertical self-weight stress of the goaf is determined; The radius of the fractured zone of the roof surrounding rock is determined based on the excavation radius, the vertical self-weight stress, the cohesion of the roof surrounding rock mass, and the internal friction angle of the roof surrounding rock mass. The foundation support force is calculated based on the radius of the fractured zone of the roof surrounding rock, the density of the roof surrounding rock, the cross-sectional width, the mining height, and the mining depth.

[0007] Optionally, the calculation of the foundation support force based on the radius of the fractured zone of the roof surrounding rock, the density of the roof surrounding rock, the cross-sectional width, the mining height, and the mining depth includes: Based on the radius of the fractured zone of the surrounding rock of the roof, the mining height, and the density of the surrounding rock of the roof, the roof load per unit area is determined; The foundation support force is calculated based on the roof load per unit area, the cross-sectional width, and the mining depth.

[0008] Optionally, determining the roof load per unit area based on the radius of the fractured zone of the surrounding rock, the mining height, and the density of the surrounding rock includes: The load per unit area of ​​the top slab is calculated using the following formula, including: ; in, The load per unit area of ​​the top slab is... The density of the surrounding rock of the roof is given. It is the acceleration due to gravity. Let be the radius of the fractured zone of the surrounding rock of the roof. The mining height is mentioned. And / or, the calculation of the foundation support force based on the roof load per unit area, the cross-sectional width, and the mining depth includes: The foundation support force is calculated using the following formula, including: ; in, For the aforementioned basic support force, The load per unit area of ​​the top slab is... The width of the cross-section, The depth of the mining operation is described above.

[0009] Optionally, determining the vertical self-weight stress of the goaf based on the density of the surrounding rock of the roof and the burial depth includes: The vertical self-weight stress is calculated using the following formula, including: ; in, The vertical self-weight stress is... The density of the surrounding rock of the roof is given. It is the acceleration due to gravity. The burial depth is [the specified depth].

[0010] Optionally, determining the radius of the fractured zone of the roof surrounding rock based on the excavation radius, the vertical self-weight stress, the cohesion of the roof surrounding rock mass, and the internal friction angle of the roof surrounding rock mass includes: The radius of the fractured zone of the surrounding rock of the roof is calculated using the following formula, including: ; in, Let be the radius of the fractured zone of the surrounding rock of the roof. The excavation radius is... The cohesion of the surrounding rock mass of the roof is given. The friction angle within the surrounding rock of the roof is given. The stress is the vertical self-weight stress.

[0011] Optionally, determining the target quantity based on the basic support force and the ultimate bearing capacity includes: Based on the support safety factor of the goaf and the basic support force, the target support force required for the goaf is determined. The number of targets is determined based on the target support force and the ultimate bearing capacity.

[0012] Based on the same inventive concept, this disclosure also provides a mining method based on large-section roof control, wherein the ore body to be mined is divided into multiple layers along the vertical direction, each layer is divided into multiple large-section mining units along the strike of the ore body, and each large-section mining unit is divided into multiple working areas along the dip of the ore body. The method includes: The mining operations are carried out sequentially from bottom to top for each layer of the ore body, and after the mining operations for each layer are completed, the layer is filled. The mining operation includes: Along the strike of the ore body, mining operations are carried out sequentially for each of the aforementioned large-section mining units, the mining operations including: Each working area is mined sequentially along the dip of the ore body. After each working area is mined out, a goaf space is formed. A target number of support columns are set in each goaf space. The target number is obtained based on the calculation method for the number of support columns described in any of the preceding items.

[0013] Optionally, each work area is divided into at least two sub-work areas along the dip of the ore body; The mining of each working area sequentially along the dip of the ore body includes: Each sub-operating area in each operating area is mined sequentially along the dip of the ore body, and after the mining of each sub-operating area is completed, initial support measures are taken for the exposed roof of that sub-operating area. The initial support measures include at least one of anchor bolts and metal mesh.

[0014] Optionally, the provision of a target number of support columns in each goaf includes: In each goaf, the target number of support pillars are installed at intervals along the strike of the ore body; Adjacent support columns within the same goaf space are connected and fixed so that all support columns within the same goaf space form an integral support structure.

[0015] As can be seen from the above, the method for calculating the number of support columns and the mining method based on large-section roof control provided in this application first calculates the required basic support force for the goaf based on the mechanical parameters, burial depth, and spatial geometric parameters of the surrounding rock of the goaf. Then, based on the basic support force and the ultimate bearing capacity of a single support column, the target number of support columns to be set in the goaf is determined, providing a feasible calculation basis for determining the number of support columns. At the same time, the calculation process fully considers the influence of the mechanical parameters, burial depth, and spatial geometric parameters of the surrounding rock of the goaf on the load and support requirements of the goaf roof, and combines the bearing capacity of the support columns themselves, making the determined target number of support columns more scientific and reasonable. While ensuring the safety of roof support, it avoids setting too many or too few support columns, thereby reducing mining safety hazards and improving operational efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram illustrating a method for calculating the number of support columns according to an embodiment of this application; Figure 2 This is a three-dimensional schematic diagram of a mining site from the main view in an embodiment of this application; Figure 3 This is a side view of a mining site according to an embodiment of this application; Figure 4 This is a top view of a mining site according to an embodiment of this application; Figure 5 This is a schematic diagram of one layer of a mining area according to an embodiment of this application; Figure 6 This is a second schematic diagram of one layer of a mining area according to an embodiment of this application; Figure 7This is a third schematic diagram of one layer of a mining area according to an embodiment of this application; Figure 8 This is a fourth schematic diagram of one layer of a mining area according to an embodiment of this application; Figure 9 This is a schematic plan view of the arrangement of support columns in one layer of a mining area according to an embodiment of this application; Figure 10 This is a schematic diagram of a device for calculating the number of support columns according to an embodiment of this application; Figure 11 This is a schematic diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0019] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] During the mining of underground ore bodies, as the ore body is gradually extracted, a certain range of mined-out spaces are formed. Under the influence of the overlying strata's own weight and the redistribution of stress in the surrounding rock, the exposed roof is prone to deformation, cracking, and even collapse and other instability phenomena. To ensure the safety of mining operations, it is usually necessary to support the exposed roof.

[0021] Roof support methods mainly include pre-existing point column support and additional support column support. Pre-existing point column support refers to retaining a portion of the ore body without mining it, using the retained ore body as a natural support for the roof. However, this method suffers from insufficient ore body mining and low mineral resource recovery rates, especially in high-value ore body mining scenarios such as metal mines and gold mines, easily leading to resource waste and affecting mining efficiency. Additional support column support refers to additionally installing support columns in the goaf area during mining. These columns support the roof without needing to retain the ore body, thus ensuring roof stability while improving mineral resource recovery rates.

[0022] The number of support pillars directly affects the roof support strength, mining safety, and cost control in the goaf, making it crucial. However, the number of support pillars is often determined by on-site personnel based on experience and construction practices, lacking a scientific and reasonable calculation method. This can lead to either too many or too few pillars. Insufficient pillars fail to meet roof support requirements, potentially causing roof subsidence, spalling, and collapse. Conversely, excessive pillars result in material waste, reduced mining efficiency, and increased operating costs.

[0023] Based on the above, this disclosure provides a method for calculating the number of support pillars to be installed, which is used to determine the target number of support pillars to be installed in the goaf during the mining process of the ore body. This method effectively improves the scientificity and rationality of determining the number of support pillars to be installed, and provides a feasible calculation basis for determining the number of support pillars to be installed.

[0024] like Figure 1 As shown, the method includes: S101. Based on the mechanical parameters, burial depth, and spatial geometric parameters of the roof surrounding rock of the goaf, calculate the required foundation support force for the goaf. Specifically, burial depth is used to characterize the burial depth of the goaf, that is, the vertical distance from the corresponding location of the goaf to the ground surface. The mechanical parameters of the roof surrounding rock can be obtained through prior geological exploration, rock sampling, and mechanical testing of the ore body and mining area; the spatial geometric parameters of the goaf can be determined according to the mining plan, or obtained through on-site measurement or field testing, with no specific restrictions. Burial depth can be determined based on prior exploration data of the ore body and in conjunction with the mining plan, or obtained through on-site measurement or field testing, with no specific restrictions. Before mining, a corresponding mining plan is usually formulated in advance to clarify the advance direction, the advance length for each advance, the expected mining range, and other mining parameters. Therefore, after obtaining the ore body exploration data and formulating the mining plan, the spatial geometric parameters and burial depth of the goaf can be determined based on the ore body occurrence and specific mining parameters.

[0025] S102. Determine the ultimate bearing capacity of a single support column; Specifically, the support columns can be concrete-filled steel tubular (CFST) columns, or other types of support columns; there are no specific limitations. CFST columns consist of seamless steel tubing and concrete filling the seamless steel tubing. The two interact to support the roof slab, offering advantages such as high load-bearing capacity and strong structural stability. The ultimate bearing capacity of a single support column can be obtained through testing or calculated based on its constituent materials and structural parameters. Taking CFST columns as an example, the load-bearing capacity of the seamless steel tubing and concrete typically has corresponding standards or design parameters. Therefore, after determining the material composition of the CFST column, its ultimate bearing capacity can be further determined.

[0026] S103. Based on the basic support force and the ultimate bearing capacity, determine the target quantity.

[0027] Specifically, the basic support force can be divided by the ultimate bearing capacity of a single support column, and the result can be rounded up to the nearest integer. The smallest positive integer greater than or equal to this result can be used as the target number, so that the total bearing capacity of the target number of support columns is not less than the basic support force.

[0028] In metal mines, the surrounding rock of the excavated roof possesses a certain self-supporting capacity. Therefore, the design of the support system must consider the combined effect of the surrounding rock and the support structure. A reasonable support force should be close to the minimum support force, that is, the critical support force corresponding to the transformation of deformation pressure into loosening pressure after excavation. This fully utilizes the self-supporting capacity of the surrounding rock, thereby designing an economical and reasonable support structure. In other words, while ensuring the stability of the goaf roof, the support capacity required by the support system should match the actual support needs of the surrounding rock, and should not be too large or too small.

[0029] Because the stress state of the roof surrounding rock redistributes after excavation, elastic zones, plastic zones, and even locally fractured zones will form within the surrounding rock. The mechanical parameters of the roof surrounding rock directly affect the development range of the fractured zone and the self-supporting capacity of the surrounding rock. The burial depth of the goaf reflects the original rock stress level formed by the self-weight of the overlying strata. The spatial geometric parameters of the goaf determine the exposed range of the roof, the stress pattern, and the load transfer path. Therefore, the mechanical parameters, burial depth, and spatial geometric parameters of the roof surrounding rock together determine the magnitude of the load borne by the exposed roof of the goaf. The exposed roof load value calculated based on the above parameters can serve as the basic support force characterizing the actual support requirements of the goaf, and can be used to further determine the number of support columns to be installed.

[0030] In this application, based on steps S101-S103, the required foundation support force for the goaf is first calculated according to the mechanical parameters, burial depth, and spatial geometric parameters of the surrounding rock of the goaf. Then, based on the foundation support force and the ultimate bearing capacity of a single support column, the target number of support columns to be installed in the goaf is determined, providing a feasible calculation basis for determining the number of support columns. At the same time, the influence of the mechanical parameters, burial depth, and spatial geometric parameters of the surrounding rock on the load and support requirements of the goaf roof is fully considered in the calculation process, and combined with the bearing capacity of the support columns themselves, making the determined target number of support columns more scientific and reasonable. While ensuring the safety of the roof support, the number of support columns is avoided from being too many or too few, thereby reducing mining safety hazards and improving operational efficiency.

[0031] In some embodiments, the mechanical parameters of the roof surrounding rock include roof surrounding rock density, roof surrounding rock mass cohesion, and roof surrounding rock internal friction angle; the spatial geometric parameters of the goaf include cross-sectional width, mining height, and mining depth. The required foundation support force for the goaf is calculated based on the mechanical parameters, burial depth, and spatial geometric parameters of the surrounding rock of the goaf, including: S201. Based on the cross-sectional width and the mining height, determine the excavation radius of the goaf; Specifically, when the cross-section of the goaf is not a standard circle, an equivalent radius can be used to characterize the excavation radius for subsequent calculations. Optionally, the excavation radius of the goaf can be calculated using the following formula: ;in, This is the excavation radius (in meters). This refers to the cross-sectional width (in meters). The mining height is shown in meters.

[0032] S202. Based on the density of the surrounding rock of the roof and the burial depth, determine the vertical self-weight stress of the goaf. S203. Based on the excavation radius, the vertical self-weight stress, the cohesion of the surrounding rock mass of the roof, and the internal friction angle of the surrounding rock mass of the roof, determine the radius of the fractured zone of the surrounding rock mass of the roof. Specifically, the radius of the fractured zone of the roof surrounding rock represents the extent to which the roof surrounding rock is damaged or loosened after excavation. Since the radius of the fractured zone is less affected by the shape of the excavation cross-section, an equivalent radius can be used to approximate the actual excavation cross-section during calculation. That is, the circumcircle radius of different cross-section shapes can be used as the excavation radius to ensure a uniform calculation of the fractured zone radius.

[0033] The radius of the fractured zone in the roof surrounding rock is influenced by the size of the goaf, the stress level of the original rock, and the rock's own resistance to failure. Specifically, the excavation radius characterizes the size of the goaf, the vertical self-weight stress characterizes the stress level caused by the weight of the overlying strata at the excavation location, and the rock mass cohesion and internal friction angle characterize the shear strength and overall stability of the roof surrounding rock. Therefore, based on the excavation radius, vertical self-weight stress, roof surrounding rock cohesion, and internal friction angle, the radius of the fractured zone in the roof surrounding rock can be reasonably determined.

[0034] S204. The foundation support force is calculated based on the radius of the fractured zone of the roof surrounding rock, the density of the roof surrounding rock, the cross-sectional width, the mining height, and the mining depth.

[0035] Specifically, the foundation support capacity is essentially the basic support capacity required to maintain the stability of the roof of the goaf. This foundation support capacity can be equivalent to the self-weight load formed by the rock mass above the exposed roof of the goaf, which is in a state of fracturing or instability. Therefore, the key to determining the foundation support capacity lies in determining the load range and self-weight of this part of the rock mass.

[0036] The radius of the fractured zone of the roof surrounding rock is used to determine the extent of the fractured surrounding rock extending upwards and outwards above the roof, that is, to determine the range of roof surrounding rock that needs to be included in the support calculation. In other words, not all the weight of the roof surrounding rock is directly borne by the support columns; rather, the weight of the rock mass within the fractured zone above the roof that has lost its self-supporting stability or requires the support system to participate in the load-bearing is mainly considered. Therefore, the radius of the fractured zone actually limits the boundary of the rock mass involved in the load calculation. The cross-sectional width and mining depth further limit the size range of the exposed roof in the goaf on the plane. The cross-sectional width corresponds to the transverse span of the exposed roof, and the mining depth corresponds to the length of the exposed roof in the advancing direction. Together, they determine the planar load range of the exposed roof. Although the mining height is not a planar dimension of the roof, it reflects the degree of spatial exposure after the formation of the goaf and the conditions for the development of surrounding rock instability. The greater the mining height, the weaker the lateral constraint is usually, and the expansion range of the fractured zone of the roof surrounding rock in space and the corresponding unstable rock mass volume will also be affected. Therefore, the mining height needs to be included in the calculation. The density of the surrounding rock in the roof is used to convert the volume of rock mass within the determined fractured zone into its corresponding weight. Thus, after determining the extent of the fractured zone, the size of the goaf, and the density of the rock mass, the load acting on the exposed roof can be further calculated, and this load can be used as the basic support force required for the goaf.

[0037] In practical applications, the mechanical parameters of the roof surrounding rock, such as the density, cohesion, and internal friction angle, can usually be obtained from preliminary exploration data; the mining plan can also usually be determined in advance before actual mining. Therefore, before actual mining, the required basic support force for the goaf can be calculated in advance based on the preliminary exploration data and mining plan, and the target number of support columns can be further determined.

[0038] Taking the upward horizontal layered filling mining method as an example, before mining, the thickness, length, and stage height of the ore body are usually determined. Based on this, the entire ore body is divided into multiple layers vertically, and then each layer is mined sequentially from bottom to top. For each layer, its cross-sectional width, height, blasting advance footage, and other data can usually be determined before the actual mining of that layer. At the same time, combined with the ore body occurrence location, elevation, and other data obtained from previous exploration, as well as the corresponding mining plan for that layer, the burial depth of the goaf formed after the mining of that layer can also be determined. Therefore, before the actual mining of that layer, the target number of support pillars required for the goaf formed after the mining of that layer can be calculated in advance.

[0039] It should be noted that a single mining layer typically forms multiple goaf spaces, and these goaf spaces within the same layer are usually mined according to the same mining plan. Therefore, the spatial geometric parameters of each goaf space within the same layer are generally the same. Furthermore, since the mechanical parameters of the roof surrounding rock of each goaf space within the same layer are usually not significantly different, and their burial depths are generally similar, for the same layer, the target number of support pillars can be calculated only once, and support pillars can be installed for each goaf space within the same layer according to this target number. Correspondingly, when mining transitions to different layers, because the vertical distance of each layer relative to the ground surface changes (i.e., the burial depth changes), it is necessary to recalculate the target number of support pillars based on the data corresponding to the goaf space in the current layer.

[0040] In this embodiment, based on steps S201 to S204, a scientific, reasonable, and effective method is provided for calculating the required basic support force for the goaf. The calculation fully considers the influence of factors such as the density of the surrounding rock, the cohesion of the surrounding rock mass, the internal friction angle of the surrounding rock mass, the cross-sectional width of the goaf, the mining height, and the mining depth on the load on the roof of the goaf. The basic support force determined in this way can more realistically reflect the support requirements of the goaf, thereby providing a reliable calculation basis for determining the target number of support columns.

[0041] In some embodiments, calculating the basic support force based on the radius of the fractured zone of the roof surrounding rock, the density of the roof surrounding rock, the cross-sectional width, the mining height, and the mining depth includes: Based on the radius of the fractured zone of the surrounding rock of the roof, the mining height, and the density of the surrounding rock of the roof, the roof load per unit area is determined; The foundation support force is calculated based on the roof load per unit area, the cross-sectional width, and the mining depth.

[0042] Specifically, the pressure borne by the support columns mainly comes from the weight of the rock itself within the plastic zone of the surrounding rock, and is unrelated to the overlying rock strata outside the plastic zone. To reasonably calculate the load on the support columns, in this embodiment, the radius of the fractured zone of the surrounding rock can be used to approximate the load-bearing influence range of the plastic zone of the surrounding rock, and the top pressure formed by the rock within this influence range can be approximately equivalent to a rectangular uniformly distributed top pressure.

[0043] Based on this, the roof load per unit area can be determined using the radius of the fractured zone of the surrounding rock, the mining height, and the density of the surrounding rock. Then, based on the roof load per unit area, the cross-sectional width, and the mining depth, the total load on the exposed roof of the goaf can be determined. The cross-sectional width and mining depth together determine the load-bearing area of ​​the exposed roof. Applying the roof load per unit area to this load-bearing area allows for the calculation of the foundation support force corresponding to the goaf. This accurately reflects the actual load borne by the exposed roof of the goaf, making the calculation results of the foundation support force more targeted and reasonable, thus providing a reliable calculation basis for the subsequent scientific determination of the target number of support columns.

[0044] In some embodiments, determining the roof load per unit area based on the radius of the fractured zone of the roof surrounding rock, the mining height, and the density of the roof surrounding rock includes: The load per unit area of ​​the top slab is calculated using the following formula, including: ; in, The load per unit area of ​​the top slab is... The density of the surrounding rock of the roof is given. It is the acceleration due to gravity. Let be the radius of the fractured zone of the surrounding rock of the roof. The mining height is mentioned. And / or, the calculation of the foundation support force based on the roof load per unit area, the cross-sectional width, and the mining depth includes: The foundation support force is calculated using the following formula, including: ; in, For the aforementioned basic support force, The load per unit area of ​​the top slab is... The width of the cross-section, The depth of the mining operation is described above.

[0045] In this embodiment, a reliable method is provided for calculating the top slab load and foundation support force per unit area. Based on the relevant formulas in this embodiment, the top slab load and foundation support force per unit area can be reasonably calculated.

[0046] In some embodiments, determining the vertical self-weight stress of the goaf based on the density of the surrounding rock of the roof and the burial depth includes: The vertical self-weight stress is calculated using the following formula, including: ; in, The vertical self-weight stress is... The density of the surrounding rock of the roof is given. It is the acceleration due to gravity. The burial depth is [the specified depth].

[0047] This embodiment provides a reliable method for calculating the vertical self-weight stress of the goaf. Based on the relevant formulas in this embodiment, the vertical self-weight stress of the goaf can be reasonably calculated.

[0048] In some embodiments, determining the radius of the fractured zone of the roof surrounding rock based on the excavation radius, the vertical self-weight stress, the cohesion of the roof surrounding rock mass, and the internal friction angle of the roof surrounding rock mass includes: The radius of the fractured zone of the surrounding rock of the roof is calculated using the following formula, including: ; in, Let be the radius of the fractured zone of the surrounding rock of the roof. The excavation radius is... The cohesion of the surrounding rock mass of the roof is given. The friction angle within the surrounding rock of the roof is given. The stress is the vertical self-weight stress.

[0049] In this embodiment, a reliable method is provided for calculating the radius of the fractured zone of the surrounding rock of the roof. Based on the relevant formulas in this embodiment, the radius of the fractured zone of the surrounding rock of the roof can be reasonably calculated.

[0050] In some embodiments, determining the target quantity based on the basic support force and the ultimate bearing capacity includes: Based on the support safety factor of the goaf and the basic support force, the target support force required for the goaf is determined. The number of targets is determined based on the target support force and the ultimate bearing capacity.

[0051] Specifically, the target support force can be calculated using the following formula: ,in, To ensure the safety factor of the support, Target support force. Support safety factor. The value can be 1.5, or 1.2, 1.3, 1.6, 1.8, etc., or it can be set to other values ​​according to the actual situation. There are no specific restrictions.

[0052] Basic support force is used to characterize the foundational support capacity required to maintain the stability of the goaf roof without considering additional safety reserves. Considering that factors such as the surrounding rock conditions of the goaf roof, on-site construction conditions, support installation deviations, and load fluctuations may affect the support effectiveness during actual mining, a support safety factor is introduced when determining the actual required support capacity. This allows for adjustments to the basic support force, thereby reserving a certain safety margin for the goaf support and further ensuring the safety and stability of the goaf roof.

[0053] In some embodiments, the support column is a steel-concrete composite column, which includes a steel pipe and concrete filled inside the steel pipe; Determining the ultimate bearing capacity of a single support column includes: The ultimate bearing capacity of a single support column is determined using the following formulas, including: when The ultimate bearing capacity of a single support column is calculated using the following formula: ; when The ultimate bearing capacity of a single support column is calculated using the following formula: ; in, For ultimate bearing capacity, This refers to the actual length of the steel-concrete composite support column. The outer diameter of the steel pipe; This represents the cross-sectional area of ​​the steel pipe. This represents the cross-sectional area of ​​the concrete inside the steel pipe. This is the design value for the compressive strength of concrete; This is the design value for the compressive strength of the steel.

[0054] For example, the following provides a specific example to illustrate in detail the method for calculating the number of support columns provided in this disclosure.

[0055] When mining a specific unit within a ore body, the space created after every two blasting advances is designated as the goaf. When calculating the target number of support pillars for this goaf, the roof rock mechanical parameters, such as roof rock density, roof rock cohesion, and roof rock internal friction angle, can be obtained from previous geological exploration data of the ore body. Assuming each blasting advance is 2m, the mining unit has a cross-sectional width of 10m and a height of 3m, and since mining of this unit is typically carried out according to the above mining plan, the goaf formed after every two blasting advances will have a cross-sectional width of 10m, a mining height of 3m, and a mining depth equal to the sum of the two blasting advances, i.e., 2 × 2m = 4m. Therefore, after obtaining the mechanical parameters of the roof surrounding rock, cross-sectional width, mining height and mining depth corresponding to the goaf, the above data can be substituted into the corresponding formula to calculate the target number of support columns required for the goaf.

[0056] The specific calculation steps are as follows: (1) Calculate the foundation support force required for the goaf.

[0057] Calculate the radius of the fractured zone of the surrounding rock of the roof. : ; ; ; in, This is the excavation radius (in meters). This refers to the cross-sectional width (in meters). The mining height is in meters. The cohesion of the surrounding rock mass of the roof (unit: MPa). The friction angle within the surrounding rock mass of the roof is expressed in degrees. This represents the vertical self-weight stress (in kN). The density of the surrounding rock of the roof is given in kg / m³. It is the acceleration due to gravity. Burial depth (in meters).

[0058] The radius of the fractured zone of the surrounding rock in the roof was obtained. Then, the basic support force was further calculated. : ; ; in, The load per unit area of ​​the top slab. The depth of the mining operation (in meters). The width of the cross section. This refers to the mining height.

[0059] (2) Determine the ultimate bearing capacity of a single support column.

[0060] The support columns are made of steel-concrete composite tubes, which consist of steel tubes and concrete filling the steel tubes. The ultimate bearing capacity of a single support column is calculated using the following formula. (Unit: kN), including: when The ultimate bearing capacity of a single support column is calculated using the following formula: ; when The ultimate bearing capacity of a single support column is calculated using the following formula: ; in, For ultimate bearing capacity, This refers to the actual length of the steel-concrete composite support column. The outer diameter of the steel pipe; This represents the cross-sectional area of ​​the steel pipe. This represents the cross-sectional area of ​​the concrete inside the steel pipe. This is the design value for the compressive strength of concrete; This is the design value for the compressive strength of the steel.

[0061] (3) Calculate the target quantity.

[0062] The target support force is calculated using the following formula. : ； The first quantity is calculated using the following formula. : ; When the first quantity is an integer, it is directly determined as the target quantity. When the first quantity is not an integer, it is rounded up, that is, the smallest integer greater than the first quantity is the target quantity.

[0063] Therefore, the required foundation support force for the goaf can be determined.

[0064] Based on the same inventive concept, this application provides a mining method based on large-section roof control, which can simultaneously improve ore recovery rate, stope safety and mining efficiency, and achieve an effective balance between safety, economy and efficiency, and has broad application prospects.

[0065] The ore body to be mined is divided into multiple layers vertically, each layer is further divided into multiple large-section mining units along the strike of the ore body, and each large-section mining unit is further divided into multiple working areas along the dip of the ore body; the mining method includes: The mining operations are carried out sequentially from bottom to top for each layer of the ore body, and after the mining operations for each layer are completed, the layer is filled. The mining operation includes: Along the strike of the ore body, mining operations are carried out sequentially for each of the aforementioned large-section mining units, the mining operations including: Each working area is mined sequentially along the dip of the ore body. After each working area is mined out, a goaf space is formed. A target number of support columns are set in each goaf space. The target number is obtained based on a method for calculating the number of support columns described in any of the foregoing embodiments.

[0066] Specifically, the cross-sectional width of the large-section mining unit is greater than 10m. Optionally, it can be 12, 13, 15, 16, 18, 20, 22, or 25m, or other values ​​can be set according to actual conditions. There are no specific restrictions. Each large-section mining unit is divided into multiple working areas, and the cross-sectional width of each working area is equal to the cross-sectional width of the large-section mining unit.

[0067] Upward horizontal layered backfilling is a commonly used mining method in high-grade metal mines, offering advantages such as low mining loss rate, low ore dilution rate, and high production efficiency. However, for thick, fractured ore bodies, using upward horizontal layered backfilling results in a large exposed stope area, failing to meet safe mining requirements. Therefore, some mines have begun to replace upward layered backfilling with point pillars, which involves leaving point pillars in the stope to support the roof. However, point pillars are prone to brittle fracture under uniaxial loads, and their placement causes significant ore resource loss. While replacing point pillars with upward access backfilling avoids point pillar losses, the smaller access cross-section and more cumbersome backfilling processes reduce stope mining and backfilling efficiency.

[0068] In this application, by installing a target number of support pillars within the goaf formed in a large-section mining unit, replacing the use of interstitial or point pillars, safe and efficient large-section blasting-roof control operations are achieved. Based on this, the layers are divided into large-section mining units. During the mining of these units, support pillars are promptly installed in the resulting goaf, ensuring mining safety while achieving large-section mining, expanding the blasting cross-section, increasing the amount of ore recovered per blast, and thus improving mining efficiency. Simultaneously, by eliminating the use of point pillars, the ore loss rate is significantly reduced while ensuring mining safety, increasing the mineral resource recovery rate. Furthermore, after completing the mining operations of each layer, large-scale unified backfilling is implemented, significantly improving backfilling efficiency, reducing the number of backfilling operations, and simplifying the construction process. In addition, using support pillars to support the goaf has advantages such as high load-bearing capacity and strong structural stability, effectively ensuring the stability of the goaf and guaranteeing mining safety while improving mining efficiency. This application can also determine the number of support pillars required for the goaf based on different surrounding rock characteristics, different mining unit cross-sectional dimensions, and different support pillar materials, thereby replacing manual experience-based judgment and improving the scientific and rational nature of determining the number of support pillars. Therefore, this application can simultaneously improve ore recovery rate, ensure stope safety, and enhance mining efficiency, achieving an effective balance between safety, economy, and efficiency, and has good application prospects.

[0069] It should be noted that, as used in this application, "roof control" refers to the timely installation of support pillars within the goaf during the mining process in the work area to support the exposed roof after mining, thereby controlling roof deformation and instability risks and maintaining the stability of the goaf. "Blasting-roof control" refers to the timely installation of support pillars to support the newly exposed roof after blasting a large-section mining unit and creating a new goaf, so that the blasting mining operation and roof stability control are interconnected.

[0070] In some embodiments, each work area is divided into at least two sub-work areas along the dip of the ore body; The mining of each working area sequentially along the dip of the ore body includes: Each sub-operating area in each operating area is mined sequentially along the dip of the ore body, and after the mining of each sub-operating area is completed, initial support measures are taken for the exposed roof of that sub-operating area. The initial support measures include at least one of anchor bolts and metal mesh.

[0071] Specifically, the working area is a large-section working area, and the sub-working areas are also large-section, with a cross-sectional width equal to that of the working area and also equal to that of the large-section mining unit. When mining each sub-working area within each working area sequentially along the dip of the ore body, blasting can be carried out first in the current sub-working area to break down the ore body within it. After blasting, the ore produced by the blasting is transported out of the current stratum to complete the mining of the current sub-working area. After the mining of the current sub-working area is completed, the roof corresponding to that sub-working area is exposed. Therefore, initial support measures are taken for the exposed roof of the sub-working area, such as installing anchor bolts or metal mesh, or both. Then, mining continues along the dip of the ore body in the next sub-working area until the sequential mining of each sub-working area within the corresponding working area is completed. Especially for thick and fractured ore bodies, the upward horizontal layered filling mining method may result in a large exposed area of ​​the stope, which may not meet the requirements for safe mining. Temporary support of the stope roof by combining anchor bolts and / or metal mesh + support pillars can effectively ensure the safety of mining.

[0072] In this embodiment, after each sub-work area is completed, initial support measures are promptly taken for the exposed roof. Subsequently, the roof of the stope is further supported in conjunction with support columns, thus forming a support method that combines anchor bolts, metal mesh and support columns. This can effectively ensure the stability of the goaf and improve the efficiency of mining while ensuring mining safety.

[0073] In some embodiments, the step of setting a target number of support columns in each goaf includes: In each goaf, the target number of support pillars are installed at intervals along the strike of the ore body; Adjacent support columns within the same goaf space are connected and fixed so that all support columns within the same goaf space form an integral support structure.

[0074] Specifically, when installing support pillars in each goaf, the support pillars can be installed sequentially along the ore body strike according to the determined target number, with each support pillar spaced apart along the ore body strike. After the support pillars are installed, adjacent support pillars within the same goaf are connected and fixed. Specifically, this can be done by connecting and fixing the support pillars in the middle using detachable top rods, thereby connecting all the support pillars arranged along the ore body strike within the goaf into a unified support structure. Through this method, the support pillars can form a row-arranged and integrally stressed support system within the goaf, improving the overall stability of the support structure, reducing the damage and impact of blasting operations on the support pillars, and thus more effectively ensuring the support stability and mining safety of the goaf.

[0075] The following section uses a gold mine as an example to provide a detailed explanation of the mining method based on large-section roof control provided in this application.

[0076] (1) Structural parameters of a gold mine mining area The stope is arranged basically perpendicular to the strike of the ore body, with a length of approximately 40m. It is mainly hosted in the footwall of the F fault zone (located on the footwall of the Jiaojia main fault, controlled and influenced by the main fault; secondary structures are mainly a group of faults trending NNE–NE, dipping NW or SE, with dip angles ranging from 25° to 85°, and fault gouge of 1–5 cm), with a thickness of 40m. It is mainly hosted between lines 135 and 137. The footwall and footwall of the ore body are clearly defined and basically parallel. The ore body strikes NNE 34°, dips NE 45°, and has a dip angle of 45°. The ore body has a bulk density of 2.7 t / m³. The ore body occurrence is relatively stable, mainly occurring as veins. The ore type is mainly pyrite-potassic granitic rock, followed by pyrite-sericite. The hanging wall is composed of biotite granite, and the footwall is potassic granite. The mineralization of the ore body is mainly vein-like and network-like, with disseminated mineralization as a secondary form. The gold minerals are found in three states: interstitial gold, fractured gold, and inclusion gold, with interstitial gold being the most prevalent. The ore grade is 1.67 g / t.

[0077] (2) Precision cutting like Figure 2 , Figure 3 , Figure 4 As shown, in this stope, auxiliary ramp 13 is used to excavate layered connecting roadways 4 and segmented roadways 5 towards ore body 9. A pass 7 is arranged to connect with the segmented roadways 5. From the segmented roadways 5, a layered connecting roadway 4 is excavated to each layer, and a cutting level roadway 3 is excavated along the contact zone. The auxiliary ramp 13 mainly serves functions such as material transport, personnel access, loader movement, ventilation, and transport of backfill material. Outside the vein (footwall), a stage haulage roadway 12 is excavated along the strike of ore body 9. From the stage haulage roadway 12, a cross-vein haulage roadway 14 is excavated towards ore body 9. The mined ore is transported by loader to the cutting level roadway 3, and then from the cutting level roadway 3, through layered connecting roadways 4 and connecting roadways 6, to the pass 7. The ore then enters the cross-vein haulage roadway 14 through the pass 7, and finally reaches the stage haulage roadway 12. The stope also includes a cross-vein return airway 8 (connecting roadway 6), a stage return airway 11, and a utility shaft 15.

[0078] The functions of each roadway in the mining area are as follows: 1) Cutting Horizontal Lane 3: This lane opens up a free face and free space for large-scale ore mining, allowing personnel and equipment to enter the cutting horizontal lane 3 via the auxiliary ramp 13 and the layered connecting lane 4, and finally enter the large-section mining unit 1. The lane cross-section is 4m × 3m.

[0079] 2) Layered connecting roadway 4: Located in the middle of ore body 9, it is used to connect segmented roadway 5 and cutting horizontal roadway 3. The cross-sectional area of ​​the roadway is 4m×3m.

[0080] 3) Sectional roadway 5: Located in the middle of ore body 9, it mainly undertakes the functions of material transportation, pedestrian and loader movement, ventilation, and transportation of filling material in each section. The cross-sectional area of ​​the roadway is 4m×3m.

[0081] 4) Connecting roadway 6: Located in the middle of ore body 9, it is used to connect ore pass 7 and segment roadway 5. The cross-sectional area of ​​the roadway is 4m×3m.

[0082] 5) Shaft 7: A chute 7 is located in the stope, connected to the connecting roadway 6, and is situated in the footwall rock. Its cross-sectional dimensions are... The shaft is 4m long, with a vertical height of 30m and an inclination angle of 85°.

[0083] 6) Main return airway 8: Connects the measures shaft 15 and the stage return airway 11. Sewage air returns through the measures shaft 15 to the stage return airway 11, and then enters the ventilation shaft to be discharged to the surface. The cross-sectional dimensions of the roadway are 4m × 4m.

[0084] 7) Stage Return Airway 11: This roadway is located in the footwall rock, with the roadway floor 186.3m below the surface and 80m horizontally from ore body 9. A loader is used for ore extraction. The roadway cross-sectional area is 4m x 4m.

[0085] 8) Stage Transport Roadway 12: This roadway is located in the footwall rock, with the roadway floor 216.3m below the surface and a horizontal distance of 80m from ore body 9. A loader is used for ore extraction. The roadway cross-section is 5m × 5m.

[0086] 9) Auxiliary ramp 13: Auxiliary ramp 13 mainly serves the functions of material transportation, pedestrian access, loader movement, ventilation, and transportation of filling material. The cross-sectional dimensions of the ramp are 5m × 5m.

[0087] 10) Main transport roadway 14: Used to connect the main transport roadway of the mining area with the ore pass 7, with a cross-sectional area of ​​5m×5m.

[0088] 11) Measure Shaft 15: A measure shaft 15 is arranged in the stope, connected to the layered connecting roadway 4, for return air, material transportation, and backfilling. It is located in the footwall rock, and its cross-sectional dimensions are... 3m, vertical height is 30m, and inclination angle is 70°.

[0089] (3) Retrieved The mining area is arranged basically perpendicular to the strike of the ore body, with a length of approximately 40m and a thickness of about 40m. For example... Figure 3 As shown, the mining area is vertically divided into 10 layers, each 3 meters high, and the ore body in each layer is mined from bottom to top. Within each layer, as... Figure 5 , Figure 6 , Figure 7 , Figure 8As shown, the ore body can be divided into four large-section mining units 1 (section width is 10m, height is 3m, and length is 40m) along the strike direction, named A, B, C, and D respectively.

[0090] During operations at this mining site, mining is carried out sequentially from bottom to top in each ore layer. Within each ore layer, mining is carried out sequentially along the strike of the ore body in each large-section mining unit 1. Within each large-section mining unit 1, mining is carried out sequentially along the dip of the ore body in each working area. After each working area is mined out, a goaf is formed, and a target number of support pillars 2 are installed in each goaf. Simultaneously, after completing the mining of each ore layer, the ore layer is backfilled to form a backfill body 10, such as... Figure 3 As shown.

[0091] by Figure 5 , Figure 6 , Figure 7 , Figure 8 For example, when mining this layer, the A unit is mined first, followed by the B, C, and D units. When mining the large-section mining unit 1, considering the actual blasting advance of 2m, a method of simultaneous mining and support is proposed. Each blasting advance of 2m constitutes a sub-working area, and every two blasting advances create a goaf. Taking unit A as an example, after the first blast (advance of 2m), anchor bolts and metal mesh are installed on the exposed roof of this sub-working area as initial support, such as... Figure 6 As shown; after the second blast (advancing 4m), anchor bolts and metal mesh are installed on the roof. Simultaneously, the target number of support columns (2) are immediately placed within the 4m range of the goaf as secondary support, as shown. Figure 7 , Figure 9 As shown. Repeat the above steps until the mining and support pillar 2 of all working areas in Unit A are completed, as shown. Figure 8 As shown. Within the same goaf, the spacing between adjacent support columns 2 can be as follows: Figure 9 The 2.5m interval shown can also be set to other intervals; there are no specific limitations. Along the mining depth direction of the goaf, the support pillars can be placed in the middle of the goaf. For example, when the mining depth of the goaf is 4m, such as... Figure 9 As shown, the support columns can be set at a distance of 2m from the boundary of the adjacent goaf.

[0092] Referring to the mining operation of Unit A, mining operations are carried out sequentially for Units B, C, and D until the mining operations of all large-section mining units are completed. For the current layer that has been mined out, the current layer is filled in one go to form a filling body 10.

[0093] The specific construction process for the longwall mining in each work area and sub-work area is set as follows: 1) Rock drilling and blasting A rock drilling rig was used for drilling. Shallow-hole blasting was employed, with a borehole depth of 3m and a diameter of 40mm. No. 2 rock emulsion explosive (cartridge specifications: diameter 32mm, cartridge weight: 300g, net weight per box: 24kg) was used, with an electric detonator igniting a digital electronic detonator. Controlled blasting techniques were used to minimize damage to the roof. To reduce the impact of blasting operations on the ore and support pillars and maintain their own supporting capacity, smooth blasting was preferred, and the borehole should be 0.5m away from the filling material. Shallow-hole blasting resulted in a more uniform distribution of explosive charge, generally leading to better fragmentation without the need for secondary crushing. Vertical boreholes were used because the ore was relatively stable.

[0094] 2) Ventilation After blasting, ventilation of the mining area is required. Forced ventilation is generally used, and the ventilation ducts are typically made of PVC flexible hoses. Fresh air enters the mining area from auxiliary ramps, layered connecting roads, and segmented roadways, cleaning the working face. Waste air then flows through the auxiliary shaft → through-pass return airway → stage return airway → stone gate → main return air shaft and is finally discharged to the surface.

[0095] 3) Ore transportation After the roof loose rocks are cleared, the ore can be extracted. The ore that has collapsed in the stope is shoveled and loaded by a loader and transported to the cutting level roadway. From the cutting level roadway, it is transported to the pass through the layered connecting roadway and the connecting roadway. The ore enters the cross-vein transport roadway through the pass and is finally transported to the stage transport main roadway.

[0096] 4) Ground pressure management ① Initial support measures: Install anchor bolts + install metal mesh For large-section mining units in the stope, after each blasting cycle and 2m advance, the exposed roof of the mined-out sub-working area is immediately supported initially using slotted bolts with metal mesh extending to the face. The bolt body is made of 20MnSi steel (HRB335 strip steel), with an outer diameter of 41.5mm, a wall thickness of 2.5mm, and a length of 1800mm; the retaining ring is made of 6mm diameter round steel and fully welded to the end of the bolt; the anchor plate is square-shaped and 150mm in size. 150mm thick, 6mm thick, with a center hole diameter of 43.5mm. The angle between the anchor bolt hole direction and the tunnel outline or the bedding plane, joint plane, or fracture plane of the surrounding rock is 75°. The anchor bolt mesh size is 900mm × 900mm. The metal mesh is woven from 6mm diameter steel bars into a warp and weft grid with a mesh size of 100mm. 100mm, single mesh sheet 1000mm The 2000mm thick metal mesh must be free of obvious rust, oil stains, and other impurities that could hinder the bonding between the steel fibers and cement. Anchor bolts must not be installed along structural surfaces or cracks. Anchor bolt trays should be installed with the concave side facing inwards and close to the rock mass; they must not be installed upside down or deformed by compression. In localized areas, additional support or other forms of support such as timber bracing may be used. Timber bracing should be made of 140mm diameter pine, 3m in length, cut to a suitable length according to site conditions. Wearing shoes and hats is required during support work.

[0097] ② Support columns: Steel-concrete composite columns are used.

[0098] Each sub-work area is mined sequentially along the dip direction of the ore body. Within each large-section mining unit, after mining out two sub-work areas (i.e., advancing one blasting cycle) and implementing initial support measures, the goaf area formed by the two sub-work areas is designated as the goaf space. A target number of steel-concrete composite pillars are then placed in the goaf space as secondary support. The target number is obtained according to a method for calculating the number of support pillars in any of the aforementioned embodiments.

[0099] The steel pipes for the steel-concrete composite support column are selected from low-carbon steel (Q235) No. 20 seamless steel pipes, with a thickness of 12mm, a concrete thickness of 325mm, and a height of 3000mm. C50 concrete is selected. Based on the structure of the steel-concrete composite support column, its requirements are determined to be... That is, adopting and The ultimate bearing capacity of a single steel-concrete composite support was calculated using the corresponding formula. Ultimately, the target number was determined to be 4 supports, meaning 4 steel-concrete composite supports were to be installed in each goaf of this layer. In total, 160 supports are required for each layer.

[0100] After each steel-concrete composite support is fixed, it is connected and fixed in the middle of each row of supports along the strike of the ore body using detachable top rods, so that the rows of supports are connected as a whole. To facilitate ore extraction, the top rods between the supports behind the working face are dismantled after each blasting operation. The above method is repeated to complete the mining and support work of the smallest working unit of the entire mining operation.

[0101] (4) Filling of goaf After all ore mining within a layer is completed, the blasting, ventilation, and transportation equipment and pipelines within the layer are dismantled, while the installed anchor bolts, metal mesh, and steel-concrete composite supports are retained. A one-time backfilling method is used to fill the goaf within each layer. The backfilling pipeline is introduced into the layer from the upper-middle section return airway, through the measures shaft, and the layer connecting roadway. A backfilling retaining wall is constructed at the junction of the layer connecting roadway and the cutting level roadway, and then the layer is uniformly backfilled as required. A graded tailings cemented backfilling method is used (the lime-sand ratio is generally 1:10), and the transportation method is gravity flow through pipelines. The continuous backfilling time is determined based on the surface backfill material reserves and the backfilling volume. After the layer is filled, the connecting roadway is closed, and the layer connecting roadway is filled using the same method. Then, the layer is uniformly raised to allow for mining of the upper layer area.

[0102] (5) Comparison of technical and economic benefits 1) Comparison with mechanized point-column upward horizontal layered filling method ①Technology Comparison Compared to the mechanized point-pillar upward horizontal layered filling method, the mining method based on large-section roof control proposed in this application, from the perspective of recovery loss, eliminates the need for point pillars of a certain size and scale, reducing the amount of pillar loss and significantly lowering the ore loss rate. From the perspective of support safety, using support pillars instead of point pillars to bear the pressure of the stope roof eliminates the need to rely on the strength of the ore itself to form a support structure, resulting in a more stable internal structure of the support body and better safety. At the same time, the number of support pillars can be determined by the aforementioned method for calculating the number of support pillars, making the quantity setting more scientific and reasonable, effectively ensuring support safety and reducing safety hazards.

[0103] ② Economic comparison When using the mechanized point-column upward horizontal layered filling method, a 4880m³ reserve needs to be left in the stope. 3 Based on the ore body density of 2.7 t / m³, and considering subsequent ore losses due to beneficiation and transportation (approximately 5%), the estimated ore loss in the stope is 4880 m³. 3 ×2.7t / m³×(1-5%)=12517.2t. Using the mining method based on large-section roof control proposed in this application, all pillars within the aforementioned stope can be recovered. Since the ore grade in the pillar area left by the mechanized upward horizontal layered filling method is lower than the average ore grade of 1.67g / t in this stope, calculating based on a pillar grade of 1.2g / t, an additional 15020.64g of gold can be recovered, approximately 13.518 million yuan.

[0104] Taking steel-concrete composite supports as an example, considering the costs of support materials, transportation, and installation, the cost is approximately 3,480 yuan per support. With 160 steel-concrete composite supports deployed per layer, and based on 10 layers, the total cost of steel-concrete composite supports required for each mining area is 5.568 million yuan.

[0105] For the original column volume, the backfilling cost of this area also needs to be considered. 425# ordinary Portland cement is used as the cementing material, and the backfilling aggregate consists of tailings from the mine's tailings dam and crushed stone transported from underground. The backfilling water is wastewater from the underground mine pit. A 1:10 cement-sand ratio is used, and the cement content is 100 kg / m³. 3 Based on a price of 200 yuan / ton, and considering the costs of tailings, gravel, and water, the cost is approximately 50 yuan / m³. 3 The filling process includes factors such as ventilation, slurry preparation, transportation, equipment wear and tear, power supply, water supply, and drainage, with an estimated cost of 30 yuan / m³. 3 Total: 80 yuan / m 3 According to 4800m 3 Based on the volume calculation of the point column, the additional backfilling cost for one mining area is 384,000 yuan.

[0106] In summary, compared to the point-pillar upward horizontal layered filling method, when using the mining method based on large-section roof control proposed in this application to mine the ore body, each stope can generate an additional revenue of 7.566 million yuan. It can be seen that, under the premise of ensuring safe production, this application significantly improves mine efficiency and has a considerable economic advantage.

[0107] 2) Comparison with the up-pass filling mining method ①Technology Comparison Assuming the mining area adopts the upward-entry backfilling method, each layer needs to be divided into 10 entry routes perpendicular to the strike of the ore body, with dimensions of 4m×3m×40m. A staggered mining method is used, with two entry routes being mined simultaneously each time. After each pair of entry routes is mined, a backfilling retaining wall is immediately erected for backfilling. After backfilling is completed, mining of the other entry routes begins.

[0108] For the upward-entry backfilling mining method, the blasting advance in this stope is approximately 2 meters. Considering the time for drilling, charging, and ore extraction, blasting one advance (2 meters) within a single advance requires one shift (8 hours). Therefore, completing the blasting of the entire 40-meter advance will take 160 hours. After mining is completed, backfilling operations are carried out on each advance. Considering the size of the advance, the time for backfilling and curing of each advance is 3 days, or 72 hours. This stope mines two advances simultaneously each time, and the backfilling and mining of each pair of advances takes a total of 232 hours. Since there are 10 advances in one layer, and this stope has 10 layers, the total time required for the upward-entry backfilling mining method in this stope is approximately 11,600 hours.

[0109] For the mining method based on large-section roof control proposed in this application, the blasting advance in the stope is approximately 2m. Considering the time for drilling, charging, and ore extraction, blasting one advance (2m) within a large-section mining unit takes 8 hours. Therefore, completing the blasting of the entire large-section mining unit requires 160 hours. Within the large-section mining unit, several support pillars need to be installed for every 4m of mining. Taking steel-concrete composite pillars as an example, the installation time for one batch of steel-concrete composite pillars is approximately 4 hours. A large-section mining unit requires five rows of steel-concrete composite pillars, so completing the installation of all pillars in the entire large-section mining unit takes 40 hours. Since there are four large-section mining units in one layer, completing the mining operation of all large-section mining units in one layer (including the time for installing support pillars) takes a total of 800 hours. After completing the mining operation of one layer (i.e., after completing the mining operation of all large-section mining units and setting up support pillars in the current layer), the entire layer is backfilled in one go. Considering the layer size and the mine's backfill supply capacity, the time for the entire layer to achieve backfilling, roof connection, and curing is 7 days, or 168 hours. In summary, it takes 968 hours to mine one layer using the mining method of this application. This stope has 10 layers, so the time required for this stope to use this method is approximately 9680 hours.

[0110] In summary, compared to the upward-entry backfilling mining method, when using the mining method based on large-section roof control proposed in this application to mine the ore body, 1920 hours, or 80 days, can be saved per stop. It can be seen that, while ensuring safe production, this application significantly improves mining efficiency and mine production capacity.

[0111] ② Economic comparison For the upward-entry backfilling mining method, as mentioned above, the backfilling process for each of the two entry routes requires a total of 232 hours (approximately 10 days), therefore, a backfilling depth of 960m is required. 3 The ore takes 10 days to mine, meaning an average of 96m³ can be recovered per day. 3 ore.

[0112] For the mining method based on large-section roof control proposed in this application, the mining and backfilling of each layer requires a total of 968 hours (approximately 40 days), so the recovery depth is 4800m. 3 The ore takes 40 days to mine, meaning an average of 120m³ can be recovered per day. 3 ore.

[0113] In summary, compared to the upward-entry backfilling mining method, when using the mining method based on large-section roof control proposed in this application to mine the ore body, an average of 24 m³ more can be extracted per day. 3 On average, an additional 720m³ of ore can be mined per month. 3Ore. Based on an ore bulk density of 2.7 t / m³, and considering ore losses (approximately 5%) due to subsequent processes such as beneficiation and transportation, the mining method proposed in this application can extract an average of 720 m³ more ore per month. 3 ×2.7t / m³×(1-5%)=1846.8t. Based on a grade of 1.67g / t, the mining method proposed in this application can recover an average of 3084.16g of gold per month, which is approximately RMB 2.776 million.

[0114] In summary, compared to the upward-entry backfilling mining method, the mining method based on large-section roof control proposed in this application can generate an average monthly increase in revenue of 2.776 million yuan. It can be seen that, under the premise of ensuring safe production, the mining method proposed in this application significantly improves mine efficiency and has a substantial economic advantage.

[0115] It should be noted that the method in this embodiment can be executed by a single device, such as a computer or server. The method can also be applied in a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0116] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0117] Based on the same inventive concept, corresponding to any of the above embodiments, this application also provides a device for calculating the number of support columns.

[0118] refer to Figure 10 The device is used to determine the target number of support pillars to be installed in the goaf during the ore body mining process, including: The support force calculation module 201 is used to calculate the basic support force required for the goaf based on the mechanical parameters of the surrounding rock of the roof, the burial depth and the spatial geometric parameters of the goaf. The bearing capacity calculation module 202 is used to determine the ultimate bearing capacity of a single support column; The quantity calculation module 203 is used to determine the target quantity based on the basic support force and the ultimate bearing capacity.

[0119] In some embodiments, the mechanical parameters of the roof surrounding rock include roof surrounding rock density, roof surrounding rock mass cohesion, and roof surrounding rock internal friction angle; the spatial geometric parameters of the goaf include cross-sectional width, mining height, and mining depth. The support force calculation module 201 is also used for: Based on the cross-sectional width and the mining height, the excavation radius of the goaf is determined; Based on the density of the surrounding rock of the roof and the burial depth, the vertical self-weight stress of the goaf is determined; The radius of the fractured zone of the roof surrounding rock is determined based on the excavation radius, the vertical self-weight stress, the cohesion of the roof surrounding rock mass, and the internal friction angle of the roof surrounding rock mass. The foundation support force is calculated based on the radius of the fractured zone of the roof surrounding rock, the density of the roof surrounding rock, the cross-sectional width, the mining height, and the mining depth.

[0120] In some embodiments, calculating the basic support force based on the radius of the fractured zone of the roof surrounding rock, the density of the roof surrounding rock, the cross-sectional width, the mining height, and the mining depth includes: Based on the radius of the fractured zone of the surrounding rock of the roof, the mining height, and the density of the surrounding rock of the roof, the roof load per unit area is determined; The foundation support force is calculated based on the roof load per unit area, the cross-sectional width, and the mining depth.

[0121] In some embodiments, determining the roof load per unit area based on the radius of the fractured zone of the roof surrounding rock, the mining height, and the density of the roof surrounding rock includes: The load per unit area of ​​the top slab is calculated using the following formula, including: ; in, The load per unit area of ​​the top slab is... The density of the surrounding rock of the roof is given. It is the acceleration due to gravity. Let be the radius of the fractured zone of the surrounding rock of the roof. The mining height is mentioned. And / or, the calculation of the foundation support force based on the roof load per unit area, the cross-sectional width, and the mining depth includes: The foundation support force is calculated using the following formula, including: ; in, For the aforementioned basic support force, The load per unit area of ​​the top slab is... The width of the cross-section, The depth of the mining operation is described above.

[0122] In some embodiments, determining the vertical self-weight stress of the goaf based on the density of the surrounding rock of the roof and the burial depth includes: The vertical self-weight stress is calculated using the following formula, including: ; in, The vertical self-weight stress is... The density of the surrounding rock of the roof is given. It is the acceleration due to gravity. The burial depth is [the specified depth].

[0123] In some embodiments, determining the radius of the fractured zone of the roof surrounding rock based on the excavation radius, the vertical self-weight stress, the cohesion of the roof surrounding rock mass, and the internal friction angle of the roof surrounding rock mass includes: The radius of the fractured zone of the surrounding rock of the roof is calculated using the following formula, including: ; in, Let be the radius of the fractured zone of the surrounding rock of the roof. The excavation radius is... The cohesion of the surrounding rock mass of the roof is given. The friction angle within the surrounding rock of the roof is given. The stress is the vertical self-weight stress.

[0124] In some embodiments, the quantity calculation module 203 is further configured to: Based on the support safety factor of the goaf and the basic support force, the target support force required for the goaf is determined. The number of targets is determined based on the target support force and the ultimate bearing capacity.

[0125] For ease of description, the above devices are described in terms of function, divided into various modules. Of course, in implementing this application, the functions of each module can be implemented in one or more software and / or hardware.

[0126] The apparatus described above is used to implement a method for calculating the number of support columns in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0127] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements a method for calculating the number of support columns as described in any of the above embodiments.

[0128] Figure 11 This embodiment illustrates a more specific hardware structure of an electronic device. The device may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0129] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0130] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0131] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0132] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0133] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0134] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0135] The electronic device described above is used to implement a method for calculating the number of support columns in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0136] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute a method for calculating the number of support columns as described in any of the above embodiments.

[0137] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0138] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute a method for calculating the number of support columns as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0139] Based on the same concept, corresponding to the methods of any of the above embodiments, this application also provides a computer program product, including computer program instructions. When the computer program instructions are run on a computer, the computer causes the computer to execute a method for calculating the number of support columns as described in any of the above embodiments, which has the beneficial effects of the corresponding method embodiments, and will not be repeated here.

[0140] It is understood that before using the technical solutions of the various embodiments in this disclosure, users will be informed of the type, scope of use, and usage scenarios of the personal information involved in an appropriate manner, and user authorization will be obtained.

[0141] For example, upon receiving a user's active request, a prompt message is sent to the user to explicitly inform them that the requested operation will require the acquisition and use of the user's personal information. This allows the user to independently choose, based on the prompt message, whether to provide personal information to the software or hardware such as electronic devices, applications, servers, or storage media performing the operations of this disclosed technical solution.

[0142] As an optional but not limited implementation, in response to a user's active request, sending a prompt message to the user can be done via a pop-up window, where the prompt message can be presented in text format. Furthermore, the pop-up window can also include a selection control allowing the user to choose "agree" or "disagree" to provide personal information to the electronic device.

[0143] It is understood that the above notification and user authorization process are merely illustrative and do not constitute a limitation on the implementation of this disclosure. Other methods that comply with relevant laws and regulations may also be applied to the implementation of this disclosure.

[0144] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0145] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0146] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0147] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the claims of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A method for calculating the number of support columns, characterized in that, The method for determining the target number of support pillars to be installed in the goaf during ore body mining includes: Based on the mechanical parameters, burial depth, and spatial geometric parameters of the roof surrounding rock of the goaf, the required foundation support force for the goaf is calculated. Determine the ultimate bearing capacity of a single support column; The target quantity is determined based on the basic support force and the ultimate bearing capacity; The mechanical parameters of the roof surrounding rock include roof surrounding rock density, roof surrounding rock mass cohesion, and roof surrounding rock internal friction angle; the spatial geometric parameters of the goaf include cross-sectional width, mining height, and mining depth. The required foundation support force for the goaf is calculated based on the mechanical parameters, burial depth, and spatial geometric parameters of the surrounding rock of the goaf, including: Based on the cross-sectional width and the mining height, the excavation radius of the goaf is determined; Based on the density of the surrounding rock of the roof and the burial depth, the vertical self-weight stress of the goaf is determined; The radius of the fractured zone of the roof surrounding rock is determined based on the excavation radius, the vertical self-weight stress, the cohesion of the roof surrounding rock mass, and the internal friction angle of the roof surrounding rock mass. The foundation support force is calculated based on the radius of the fractured zone of the roof surrounding rock, the density of the roof surrounding rock, the cross-sectional width, the mining height, and the mining depth.

2. The method for calculating the number of support columns according to claim 1, characterized in that, The calculation of the foundation support force based on the radius of the fractured zone of the roof surrounding rock, the density of the roof surrounding rock, the cross-sectional width, the mining height, and the mining depth includes: Based on the radius of the fractured zone of the surrounding rock of the roof, the mining height, and the density of the surrounding rock of the roof, the roof load per unit area is determined; The foundation support force is calculated based on the roof load per unit area, the cross-sectional width, and the mining depth.

3. The method for calculating the number of support columns according to claim 2, characterized in that, The determination of the roof load per unit area based on the radius of the fractured zone of the surrounding rock, the mining height, and the density of the surrounding rock includes: The load per unit area of ​​the top slab is calculated using the following formula, including: ； in, The load per unit area of ​​the top slab is [not specified]. The density of the surrounding rock of the roof is given. It is the acceleration due to gravity. Let be the radius of the fractured zone of the surrounding rock of the roof. The mining height is mentioned. And / or, the calculation of the foundation support force based on the roof load per unit area, the cross-sectional width, and the mining depth includes: The foundation support force is calculated using the following formula, including: ； in, For the aforementioned basic support force, The load per unit area of ​​the top slab is [not specified]. The width of the cross-section, The depth of the mining operation is described above.

4. The method for calculating the number of support columns according to claim 1, characterized in that, The determination of the vertical self-weight stress of the goaf based on the density of the surrounding rock of the roof and the burial depth includes: The vertical self-weight stress is calculated using the following formula, including: ； in, The vertical self-weight stress is... The density of the surrounding rock of the roof is given. It is the acceleration due to gravity. The burial depth is [the specified depth].

5. The method for calculating the number of support columns according to claim 1, characterized in that, The determination of the radius of the fractured zone of the roof surrounding rock based on the excavation radius, the vertical self-weight stress, the cohesion of the roof surrounding rock mass, and the internal friction angle of the roof surrounding rock mass includes: The radius of the fractured zone of the surrounding rock of the roof is calculated using the following formula, including: ； in, Let be the radius of the fractured zone of the surrounding rock of the roof. The excavation radius is... The cohesion of the surrounding rock mass of the roof is given. The friction angle within the surrounding rock mass of the roof is given. The stress is the vertical self-weight stress.

6. The method for calculating the number of support columns according to claim 1, characterized in that, Determining the target quantity based on the basic support force and the ultimate bearing capacity includes: Based on the support safety factor of the goaf and the basic support force, the target support force required for the goaf is determined. The number of targets is determined based on the target support force and the ultimate bearing capacity.

7. A mining method based on large-section roof control, characterized in that, The ore body to be mined is divided into multiple layers vertically, each layer is further divided into multiple large-section mining units along the strike of the ore body, and each large-section mining unit is further divided into multiple working areas along the dip of the ore body. The method includes: The mining operations are carried out sequentially from bottom to top for each layer of the ore body, and after the mining operations for each layer are completed, the layer is filled. The mining operation includes: Along the strike of the ore body, mining operations are carried out sequentially for each of the aforementioned large-section mining units, the mining operations including: Each working area is mined sequentially along the dip of the ore body. After each working area is mined out, a goaf space is formed. A target number of support columns are set in each goaf space. The target number is obtained based on the method for calculating the number of support columns as described in any one of claims 1 to 6.

8. A mining method based on large-section roof control according to claim 7, characterized in that, Each work area is divided into at least two sub-work areas along the dip of the ore body; The mining of each working area sequentially along the dip of the ore body includes: Each sub-operating area in each operating area is mined sequentially along the dip of the ore body, and after the mining of each sub-operating area is completed, initial support measures are taken for the exposed roof of that sub-operating area. The initial support measures include at least one of anchor bolts and metal mesh.

9. A mining method based on large-section roof control according to claim 7, characterized in that, The provision of a target number of support columns in each goaf includes: In each goaf, the target number of support pillars are installed at intervals along the strike of the ore body; Adjacent support columns within the same goaf space are connected and fixed so that all support columns within the same goaf space form an integral support structure.

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