Top pillar thickness determination method and device for open stoping subsequent filling mining method and medium

Abstract

The invention relates to the technical field of mining, and provides a method and a device for determining the thickness of a top pillar of an open stope subsequent filling mining method and a medium, and the method comprises the following steps: firstly, obtaining structural information of a stope; the structural information comprises stope area information and stope area size information, the stope area information comprises a top column, a filling body area and a stope area, the top column is located on the upper portion of the filling body area and the upper portion of the stope area, and the structure of the top column comprises an elastic foundation beam-common beam-elastic foundation beam combined structure; secondly, constructing a target equation about the filling body area and the stope area and constraint conditions for the target equation; and finally, determining the thickness of the top pillar based on the target equation, the constraint condition and the size information of the stope area. According to the embodiment, the target equation and the constraint condition are constructed, the thickness of the top pillar in the open stope subsequent filling mining method is determined based on the structural information of the stope, the safety of mining operation is effectively improved, and the resource utilization rate is optimized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of mine mining, and in particular, to a method, device, and medium for determining the thickness of a crown pillar in an open stope subsequent filling mining method. Background Art

[0002] With the gradual reduction of shallow resources in China, the underground metal mine mining has gradually become the mainstream. Although the traditional caving method and open stope method have been widely used, they often lead to surface subsidence, environmental pollution, and safety hazards. Especially, a large amount of solid waste generated during the underground mining process requires land for disposal, and the stacking yard often becomes a major safety hazard.

[0003] In recent years, the filling mining method has become an important method for underground mining of metal mines due to its advantages such as safety and environmental protection. In particular, more than 60 mines in the iron mine field have implemented the filling method, and new designed mines generally conduct filling mining demonstration, gradually replacing the dominant position of the caving method.

[0004] The open stope subsequent filling method combines the advantages of the open stope method and the filling method and has been adopted by many large metal mines. In this method, the safety thickness of the crown pillar is a key factor in mine design. If the crown pillar is too thin, it may cause the collapse of the stope and surface subsidence, while if it is too thick, it will waste resources. Currently, the calculation of the crown pillar thickness mainly uses the analytical method. However, although the analytical method is simple and intuitive, the existing methods mostly target a single goaf and ignore the interaction effect between the filling body and the crown pillar in the open stope subsequent filling method. Therefore, the existing calculation methods have certain limitations and need to be further optimized to adapt to more complex mine mining conditions. Summary of the Invention

[0005] The embodiments of the present disclosure at least provide a method, device, and medium for determining the thickness of a crown pillar in an open stope subsequent filling mining method. By constructing a target equation and constraint conditions and determining the thickness of the crown pillar in the open stope subsequent filling mining method based on the structural information of the mining stope, the safety of the mining operation is effectively improved, and the resource utilization rate is optimized.

[0006] The embodiments of the present disclosure provide a method for determining the thickness of a crown pillar in an open stope subsequent filling mining method, including:

[0007] Obtaining the structural information of the mining stope; wherein, the structural information includes the mining stope area information and the mining stope area size information, and the mining stope area information includes the crown pillar, the filling body area, and the stope area; the crown pillar is located above the filling body area and the stope area, and the structure of the crown pillar includes a combined structure of an elastic foundation beam - ordinary beam - elastic foundation beam.

[0008] Constructing a target equation for the filling body area and the stope area and constraint conditions for the target equation;

[0009] Determine the thickness of the crown pillar based on the target equation, the constraint conditions, and the size information of the mining area.

[0010] In some possible embodiments, the filling body area includes a first filling body area and a second filling body area, wherein the first filling body area and the second filling body area are respectively distributed at both ends of the stope area.

[0011] In some possible embodiments, the size information of the mining area includes filling body area information, stope area information, and crown pillar information;

[0012] The target equation includes:

[0013]

[0014] Wherein, E represents the elastic modulus of the filling body in the filling body area; I represents the moment of inertia of the crown pillar section; k represents the coefficient of subgrade reaction; w(x) represents the deflection at position x; represents the size information of the first filling body area; l 2 represents the size information of the stope area; q represents the load borne by the upper part of the crown pillar, l 1 represents the size information of the second filling body area.

[0015] In some possible embodiments, the constraint conditions include:

[0016]

[0017] Wherein, w 1 represents the deflection at the position of the crown pillar of the elastic foundation beam above the first filling body area; w 2 represents the deflection at the position of the crown pillar of the ordinary beam above the stope area; w 3 represents the deflection at the position of the crown pillar of the elastic foundation beam above the second filling body area.

[0018] In some possible embodiments, the determining the thickness of the crown pillar based on the target equation, the constraint conditions, and the size information of the mining area includes:

[0019] Determine the deflection of the crown pillar based on the target equation and the constraint conditions;

[0020] Solve for the crown pillar variable value of the mining area based on the deflection of the crown pillar and the crown pillar variable expression; wherein, the crown pillar variable expression includes a bending moment variable expression; the crown pillar variable value includes the maximum bending moment value;

[0021] Obtain the tensile strength of the crown pillar, and determine the thickness of the crown pillar based on the tensile strength and the maximum bending moment value.

[0022] In some possible embodiments, the bending moment variable expression includes:

[0023]

[0024] where M(x) represents the bending moment value at position x.

[0025] In some possible embodiments, determining the thickness of the top pillar based on the tensile strength and the maximum bending moment value includes:

[0026] Determining the thickness of the top pillar based on a thickness calculation formula, the tensile strength, and the maximum bending moment value;

[0027] The thickness calculation formula includes:

[0028]

[0029] where h represents the thickness of the top pillar; M represents the maximum bending moment value; and σ represents the tensile strength of the top pillar.

[0030] An embodiment of the present disclosure provides a device for determining the thickness of the top pillar in an open stope subsequent filling mining method, including:

[0031] An information acquisition module, configured to acquire the structural information of the mining stope; wherein, the structural information includes the mining stope area information and the mining stope area size information, and the mining stope area information includes a top pillar, a filling body area, and a stope area; the top pillar is located above the filling body area and the stope area, and the structure of the top pillar includes a combined structure of an elastic foundation beam - ordinary beam - elastic foundation beam;

[0032] An equation construction module, configured to construct a target equation for the filling body area and the stope area and constraint conditions for the target equation;

[0033] A thickness determination module, configured to determine the thickness of the top pillar based on the target equation, the constraint conditions, and the mining stope area size information.

[0034] In some possible embodiments, the filling body area includes a first filling body area and a second filling body area, wherein the first filling body area and the second filling body area are respectively distributed at both ends of the stope area.

[0035] In some possible embodiments, the mining stope area size information includes filling body area information, stope area information, and top pillar information;

[0036] The target equation includes:

[0037]

[0038] Among them, E represents the elastic modulus of the filling body in the filling body area; I represents the moment of inertia of the top pillar section; k represents the coefficient of subgrade reaction; w(x) represents the deflection at position x; represents the dimensional information of the first filling body area; l 2 represents the dimensional information of the stope area; q represents the load borne by the upper part of the top pillar, l 1 represents the dimensional information of the second filling body area.

[0039] In some possible embodiments, the constraint conditions include:

[0040]

[0041]

[0042] Among them, w 1 represents the deflection at the position of the top pillar of the elastic foundation beam above the first filling body area; w 2 represents the deflection at the position of the top pillar of the ordinary beam above the stope area; w 3 represents the deflection at the position of the top pillar of the elastic foundation beam above the second filling body area.

[0043] In some possible embodiments, the thickness determination module is specifically configured to:

[0044] Determine the deflection of the top pillar based on the target equation and the constraint conditions;

[0045] Solve for the top pillar variable value of the mining field based on the deflection of the top pillar and the top pillar variable expression; wherein, the top pillar variable expression includes a bending moment variable expression; the top pillar variable value includes the maximum bending moment value;

[0046] Obtain the tensile strength of the top pillar, and determine the thickness of the top pillar based on the tensile strength and the maximum bending moment value.

[0047] In some possible embodiments, the bending moment variable expression includes:

[0048]

[0049] Among them, M(x) represents the bending moment value at position x.

[0050] In some possible embodiments, the thickness determination module is specifically configured to:

[0051] Determine the thickness of the top pillar based on the thickness calculation formula, the tensile strength and the maximum bending moment value;

[0052] The thickness calculation formula includes:

[0053]

[0054] Among them, h represents the thickness of the top pillar; M represents the maximum bending moment value; σ represents the tensile strength of the top pillar.

[0055] An embodiment of the present disclosure provides a computer device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the computer device runs, the processor communicates with the memory through the bus. When the machine-readable instructions are executed by the processor, the method for determining the thickness of the top pillar of the open stope subsequent filling mining method described in any of the above possible implementation manners is executed.

[0056] An embodiment of the present disclosure provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is run by a processor, the method for determining the thickness of the top pillar of the open stope subsequent filling mining method described in any of the above possible implementation manners is implemented.

[0057] The method, device, and medium for determining the thickness of the top pillar of the open stope subsequent filling mining method provided in the embodiments of the present disclosure comprehensively consider the structural information of the mining stope, that is, the division and size information of the top pillar, the filling body area, and the stope area, and the characteristics of the top pillar as a combined structure of an elastic foundation beam - ordinary beam - elastic foundation beam. By constructing a target equation for the filling body area and the stope area, setting corresponding constraint conditions, and calculating the thickness of the top pillar in the open stope subsequent filling mining method, the safety of the mining operation is effectively improved, the safety accidents that may be caused by improper thickness of the top pillar are avoided, and the resource utilization rate is also optimized.

[0058] To make the above objects, features, and advantages of the present disclosure more obvious and understandable, the following specific preferred embodiments are given below and described in detail in conjunction with the accompanying drawings. Description of the Drawings

[0059] To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the accompanying drawings required to be cited in the embodiments will be briefly introduced below. The accompanying drawings herein are incorporated into the specification and constitute a part of this specification. These drawings show embodiments consistent with the present disclosure and are used together with the specification to illustrate the technical solutions of the present disclosure. It should be understood that the following drawings only show some embodiments of the present disclosure and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0060] Figure 1 Shows a flowchart of a method for determining the thickness of the top pillar of an open stope subsequent filling mining method provided by an embodiment of the present disclosure;

[0061] Figure 2 Shows a schematic diagram of a mining area provided by an embodiment of the present disclosure;

[0062] Figure 3 Shows a schematic diagram of a stope panel model provided by an embodiment of the present disclosure;

[0063] Figure 4 Shows a schematic structural diagram of a device for determining the thickness of the crown pillar of an open stoping and subsequent backfilling mining method provided by an embodiment of the present disclosure;

[0064] Figure 5 Shows a schematic structural diagram of a computer device provided by an embodiment of the present disclosure. Detailed implementation manners

[0065] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are only some of the embodiments of the present disclosure, rather than all the embodiments. The components of the embodiments of the present disclosure described and illustrated herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the present disclosure claimed, but merely represents selected embodiments of the present disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without creative efforts fall within the scope of protection of the present disclosure.

[0066] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0067] The term "and / or" in this article merely describes an associated relationship and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, both A and B exist simultaneously, and B exists alone. In addition, the term "at least one" in this article means any one of multiple types or any combination of at least two of multiple types. For example, including at least one of A, B, and C may represent including any one or more elements selected from the set composed of A, B, and C.

[0068] With the gradual depletion of shallow resources in China, more and more metal mines are adopting underground mining or transitioning from open-pit to underground mining, and the proportion of underground mining is gradually increasing. In the early days, caving method and open stoping method were mainly used in underground mining. These mining methods either caused large-scale surface subsidence and damaged surface buildings, farmland, roads, etc., or formed a large number of goafs, posing potential safety hazards to surrounding mine exploitation or land use. In addition, a large amount of land is needed to dispose of the solid waste generated by underground mining, and the solid waste yard is often a major accident hazard source and environmental pollution source. Due to its safety and environmental protection advantages, filling method mining has become an important or even the primary mining method for underground mining of metal mines. In the field of iron mines, according to incomplete statistics, more than 60 iron mines in China have implemented filling method mining, and newly designed underground mines, including open-pit to underground mines, basically need to carry out filling mining demonstration, completely breaking the dominant position of caving method in iron mines in the past. Among the filling mining methods, the open stoping with subsequent filling method is adopted by more and more large iron mines due to its advantages such as strong production capacity, high resource utilization rate, safe operation and good environmental protection benefits, such as Zhangzhuang Iron Mine and Lilou Iron Mine in Huoqiu area of Anhui Province, Macheng Iron Mine in Hebei Province, Chentaigou Iron Mine and Xianshan Iron Mine in Liaoning Province.

[0069] It has been found through research that the open stoping with subsequent filling method is developed on the basis of combining the original open stoping method and filling method. Its main body is the open stoping method, so the safety thickness of the crown pillar is an important parameter for mine design. On the one hand, if the crown pillar is set too thin, there will be potential safety hazards. Especially for mines in the Huoqiu area of Anhui Province under the thick Quaternary strata containing quicksand layer, if the crown pillar collapses, shaft flooding accidents will occur, and at the same time, surface subsidence will also be caused. On the other hand, if the crown pillar is set too thick, it will also cause a huge waste of mineral resources. The literature reports on the determination of the crown pillar safety thickness mainly focus on the boundary crown pillar in open-pit to underground mining, and secondly on the determination of the safety roof thickness of the goaf in underground to open-pit mining mines represented by Sandaozhuang Molybdenum Mine and Yuanjiacun Iron Mine. At present, the calculation of the crown pillar thickness mainly adopts the analytical method. However, although the analytical method is simple and intuitive, the existing methods mostly target single goafs and ignore the interaction effect between the filling body and the crown pillar in the open stoping with subsequent filling method. Therefore, the existing calculation methods have certain limitations and need to be further optimized to adapt to more complex mine exploitation conditions.

[0070] Based on the above research, in the embodiments of the present disclosure, a method, device, and medium for determining the thickness of the crown pillar in the open stope subsequent filling mining method are provided. First, obtain the structural information of the mining stope; wherein, the structural information includes the mining stope area information and the mining stope area size information, and the mining stope area information includes the crown pillar, the filling body area, and the stope area. The crown pillar is located above the filling body area and the stope area, and the structure of the crown pillar includes a combined structure of elastic foundation beam - ordinary beam - elastic foundation beam; secondly, construct the target equation for the filling body area and the stope area and the constraint conditions for the target equation; finally, determine the thickness of the crown pillar based on the target equation, the constraint conditions, and the mining stope area size information.

[0071] In the embodiments of the present disclosure, the structural information of the mining stope is comprehensively considered, that is, the division and size information of the crown pillar, the filling body area, and the stope area, as well as the characteristics of the crown pillar as a combined structure of elastic foundation beam - ordinary beam - elastic foundation beam. By constructing the target equation for the filling body area and the stope area, setting the corresponding constraint conditions, and calculating the thickness of the crown pillar in the open stope subsequent filling mining method, the safety of the mining operation is effectively improved, the safety accidents that may be caused by improper crown pillar thickness are avoided, and the resource utilization rate is also optimized.

[0072] To facilitate the understanding of this embodiment, first, the execution subject of the method for determining the thickness of the crown pillar in the open stope subsequent filling mining method provided by the embodiments of the present disclosure is introduced in detail. The execution subject of the method for determining the thickness of the crown pillar in the open stope subsequent filling mining method provided by the embodiments of the present disclosure is a computer device. This computer device can be a server. Among them, the server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud storage, big data, and artificial intelligence platforms.

[0073] The following will describe in detail the method for determining the thickness of the crown pillar in the open stope subsequent filling mining method provided by the embodiments of the present application with reference to the accompanying drawings. Refer to Figure 1 As shown, it is a flowchart of a method for determining the thickness of the crown pillar in the open stope subsequent filling mining method provided by the embodiments of the present disclosure. The method includes the following S101 - S103:

[0074] S101, obtain the structural information of the mining stope.

[0075] It can be understood that in open-stope subsequent backfilling, production is generally organized with panels as the mining units, and panel pillars are set between panels. For steeply inclined thick ore bodies, the panel can be divided into a first-stage stope and a second-stage stope according to the mining sequence. The first-stage stope and the second-stage stope are arranged at intervals. The filling after the first-stage stope mining should provide a stable surrounding environment for the second-stage stope. Therefore, a cemented filling body with a certain strength is required. After the first-stage stope is filled and cured, it serves as the ore pillar during the mining of its adjacent second-stage stope. Here, the mining task of the first-stage stope is not considered temporarily in this disclosure. Instead, the part formed after the first-stage stope mining and reinforced by the strength cemented filling body is regarded as a part of the mining area of this disclosure. In this way, the filling body of the first-stage stope can be fully utilized as the support structure for the second-stage stope, reducing the risks and costs during subsequent mining processes.

[0076] Specifically, the structural information includes the mining area information and the mining area dimension information. The mining area information includes the division of different functional areas within the mining area, such as the crown pillar, the filling body area, and the stope area. Among them, the stope area specifically refers to the working area of the second-stage stope, which is the main target of this mining operation. The filling body area includes a first filling body area and a second filling body area, which are respectively distributed at both ends of the stope area, playing a role in support and buffering; the crown pillar is located above the filling body area and the stope area, and is one of the main support structures of the mining area. In this disclosure, the crown pillar is designed as a combined structure of elastic foundation beam - ordinary beam - elastic foundation beam, aiming to make full use of the mechanical properties of different materials to improve the bearing capacity and stability of the crown pillar. Specifically, the ordinary beam provides the main bearing capacity, and the elastic foundation beam can absorb and disperse the uneven settlement of the foundation, thereby further improving the overall stability of the crown pillar. For details, please refer to Figure 2 As shown, taking the mining area in the figure as an example, the mining area specifically includes a first filling body area A, a stope area B, a second filling body area C, and a crown pillar D; it also includes panel pillars E set between panels in the mining area.

[0077] Exemplarily, the mining area dimension information can include the filling body area information, the stope area information, and the crown pillar information. The filling body area information includes information such as the elastic modulus of the filling body in the filling body area, the length and width scales of the filling body area (the first filling body area and the second filling body area), etc.; the stope area information includes information such as the length and width scales of the stope area; the crown pillar information includes information such as the cross-sectional moment of inertia of the crown pillar and the load borne by the upper part of the crown pillar.

[0078] S102, construct the target equation regarding the filling body area and the stope area and the constraint conditions for the target equation.

[0079] It is understandable that for the top pillar of the analysis object panel area, a coordinate system is established with its center as the origin, the horizontal right direction as the x-axis, and the vertical downward direction as the y-axis. In this disclosure, taking the 5-stope panel symmetry model as an example, as Figure 3 shown, where the spans of the backfill area and the stope area are l 1 and l 2 respectively, the thickness of the top pillar is h, the load borne by the upper part of the top pillar is q, with the unit of MN / m, which can be determined comprehensively by the weight of the top pillar, overlying surcharge, accumulated water, etc.

[0080] Here, the target equation can be expressed as:

[0081]

[0082] where E represents the elastic modulus of the backfill in the backfill area; I represents the moment of inertia of the top pillar cross-section; k represents the subgrade reaction coefficient; w(x) represents the deflection at position x; represents the dimensional information of the first backfill area; l 2 represents the dimensional information of the stope area; q represents the load borne by the upper part of the top pillar; l 1 represents the dimensional information of the second backfill area.

[0083] Here, for the subgrade reaction coefficient k, this disclosure proposes that due to the large thickness of the backfill, according to the elastic half-space subgrade model, the bedding coefficient can be calculated according to the absolutely rigid foundation and a certain reduction is given to the backfill as:

[0084]

[0085] where b represents the unit width; μ represents the Poisson's ratio of the backfill; α represents the reduction coefficient of the bedding coefficient. In this disclosure, due to the limited width of the cemented backfill, the subgrade reaction coefficient at the edge is significantly lower than that at the middle part. Through finite element calculation, it can be known that the subgrade reaction coefficient at the edge is one-third of that at the middle part. Therefore, α can be taken as 2 / 3 in this disclosure.

[0086] Here, the objective function proposed in this disclosure is constructed for the panel of the second-step stope. For the panels of more stopes, the number of top pillars and the functions corresponding to different stope area ranges can be continuously increased, which will not be specifically limited here.

[0087] Exemplarily, according to the elastic foundation beam theory, the target equation is a fourth-order non-homogeneous linear differential equation with constant coefficients, and its solution is the superposition of the general solution of the homogeneous equation and the particular solution. Therefore, the first section of the top pillar is an elastic foundation beam, and its solution can be written as:

[0088] w 1 (x) = A 1 X 1+A 2 X 2 +A 3 X 3 +A 4 X 4 ;

[0089]

[0090] Among them, A 1 ~A 4 is the first undetermined integral constant of the top column;

[0091] Here, the second section of the top column is a common beam, and its solution can be written as:

[0092]

[0093] Among them, B 1 ~B 4 is the second undetermined integral constant of the top column.

[0094] Here, the third section of the top column is also an elastic foundation beam, which is the same as the first section of the top column, and its solution can be written as:

[0095] w 3 (x) = C 1 X 1 +C 2 X 2 +C 3 X 3 +C 4 X 4 ;

[0096] Among them, C 1 ~C 4 is the first undetermined integral constant of the top column.

[0097] It can be understood that according to the above formula, the first to third order derivatives of the deflection of the top column can be obtained. Since the first and third sections of the top column are both elastic foundation beams and have the same expression form, only the integrals of the first and second sections are written below.

[0098] Specifically, the first integral is:

[0099] w 1 ' = β[A 1 (X 1 +X 2 ) - A 2 (X 1 -X 2 ) - A 3 (X 3 -X 4)-A 4 (X 3 +X 4 )];

[0100]

[0101] The second-order integral is:

[0102] w 1 ”=2β(C 1 X 2 -C 2 X 1 -C 3 X 4 +C 4 X 3 );

[0103]

[0104] The third-order integral is:

[0105] w 1 ”'=2β 3 [-A 1 (X 1 -X 2 )-A 2 (X 1 +X 2 )+A 3 (X 3 +X 4 )-A 4 (X 3 -X 4 )];

[0106]

[0107] Here, the model of the top column is symmetric, and the rotation angle and shear force of the top column at the left end (x = 0) are zero; the right end of the top column is fixed-connected, and the corresponding deflection and rotation angle are both zero. Therefore, it can be written as:

[0108]

[0109] In addition, since the entire top column beam is a continuous beam, the segmented connection points must satisfy the continuity conditions, that is, the deflection, rotation angle, bending moment, and shear force of the beam are all equal. That is, the constraint conditions can be expressed as:

[0110]

[0111] Among them, w 1 represents the deflection at the position of the top column of the elastic foundation beam above the first backfill area; w 2Denoted as the deflection at the position of the ordinary beam top pillar in the upper part of the stope area; w 3 Denoted as the deflection at the position of the elastic foundation beam top pillar in the upper part of the second backfill area.

[0112] S103. Determine the thickness of the top pillar based on the objective equation, the constraint conditions, and the size information of the mining area.

[0113] It can be understood that the deflection of the top pillar can be obtained by solving the system of equations according to the first to third derivatives of the top pillar deflection and the constraint conditions.

[0114] Specifically, after obtaining the deflection of the top pillar, the value of the top pillar variable regarding the stope can be solved based on the deflection of the top pillar and the top pillar variable expression; among them, the top pillar variable expression includes the bending moment variable expression; the top pillar variable value includes the maximum bending moment value. The bending moment reflects the internal force acting on the structure during the bending process, and the maximum bending moment value can directly affect the bending resistance of the beam.

[0115] Among them, the bending moment variable expression can be expressed as:

[0116]

[0117] Among them, M(x) is denoted as the bending moment value at position x;

[0118] In some other embodiments, due to the complex geological conditions of the stope, the variable loads borne by the top pillar, and the differences in the material properties of the top pillar, these factors may all cause the top pillar to be affected not only by the bending moment but also by the rotation angle and shear force during the deformation process. Therefore, the top pillar variable expression can also include the rotation angle variable expression and the shear force variable expression. The rotation angle variable expression describes the change in the rotation angle of each point of the top pillar during the deformation process, while the shear force variable expression reflects the internal force acting on the top pillar during the shear deformation process.

[0119] Among them, the rotation angle variable expression can be expressed as:

[0120]

[0121] The shear force expression can be expressed as:

[0122]

[0123] Here, when determining the thickness of the top pillar, the present disclosure first determines the thicknesses of multiple top pillars, and then solves according to the above formula to obtain the bending moments and the maximum cross-sectional normal stress distributions of top pillars with different thicknesses. It can be understood that the bending moment of the top pillar gradually increases with the increase of the thickness, but the cross-sectional normal stress gradually decreases in the second-step stope and gradually increases at the edge of the panel, and the increasing amplitude becomes smaller and smaller. In view of the fact that the proportion of the supporting force of the filling to resist deformation gradually decreases with the increase of the top pillar thickness, the maximum cross-sectional normal stress at this place will decrease after increasing to a certain value. Since the tensile strength of the rock mass is much smaller than the compressive strength, and according to the beam theory, the top pillar cross-section is more likely to undergo tensile failure, so the maximum tensile stress of the top pillar reaching the allowable tensile strength is taken as the failure condition. During the second-step mining of the panel, although the maximum stress is located at the end of the top pillar, the first-step stope has been filled at this time, so only the top pillar above the second-step stope is considered in this paper.

[0124] Here, the specific position of the maximum bending moment value is at the of the top pillar. After obtaining the compressive strength of the top pillar, taking the tensile strength of the top pillar rock mass as the allowable maximum stress, the safety thickness of the top pillar can be obtained by using the interpolation method. The specific thickness calculation formula can be expressed as:

[0125]

[0126] Among them, h represents the thickness of the top pillar; M represents the maximum bending moment value; σ represents the tensile strength of the top pillar.

[0127] Exemplarily, for a better understanding of this solution, the following takes an embodiment of the present disclosure as an example to elaborate on this solution in detail. The present disclosure takes the open-pit to underground mining of Xujia Gully Iron Mine in Panzhihua, Sichuan as an example to carry out the deformation and internal force analysis of the boundary crown pillar. Xujia Gully Iron Mine is 1.2 km long from north to south and 0.8 km wide from east to west. It is located beside the Jinsha River. There are a highway and a branch railway crossing the mining area on its north side and south side respectively. The highest bench elevation of the open-pit stope is 1340 m, the open-pit bottom elevation is between 1055 and 1065 m, the maximum slope height of the north slope of the stope is 141 m, the overall slope angle is 29.4°, and the bench slope angle is 35° - 72°. The maximum slope height of the west slope of the stope is 198 m, and the overall slope angle is 34.2°. The ore body consists of three ore bodies occurring in layers and near-layered adjacent and parallel to each other, with a total thickness of 64.97 - 115.05 m. The distance between each ore body ranges from 0 to 50 m, and the dip angle is 5 - 60°. The underground ore body is mined by the open stoping and subsequent backfilling method. It is designed to arrange a panel every 90 m perpendicular to the strike, and 5 stopes with a length of 15 m are arranged perpendicular to the ore body strike in each panel. The width of the panel pillar is also 15 m. The main surrounding rocks of the stope are ore, low-grade ore, and medium-grained gabbro. The uniaxial compressive strengths of the three rocks are 80.02 MPa, 74.81 MPa, and 71.81 MPa respectively. The rock mass quality index RMR is between 52.4 and 54.8, which are relatively close. According to the elastic modulus and Poisson's ratio of the cemented filling body, the foundation coefficient k of the cemented filling body is calculated to be 681 MPa / m. The deformation and internal force of the boundary crown pillar of Xujia Gully Iron Mine are calculated based on the Python language and the symbolic calculation mathematics library Sympy.

[0128] When analyzing the calculation results, the present disclosure takes the crown pillar thickness of 10 m as an example to analyze the deformation and internal force of the crown pillar. The traditional calculation of the crown pillar deformation based on the beam and slab theory only analyzes the currently mined stope. For a stope with a width of 15 m, the maximum deflection of the crown pillar at the middle position of the stope is 0.051 mm; while considering the deformation of the filling body, the maximum deformation of the crown pillar is at the near-middle position of the second-step stope, which is 0.854 mm. Obviously, not considering the deformation of the filling body will significantly underestimate the deformation of the crown pillar. If the supporting effect of the filling body is completely not considered, the maximum deflection of the crown pillar of the entire panel occurs in the middle of the panel, which is 25.77 mm. Obviously, this is also unreasonable.

[0129] When the deformation of the cemented filling body is not considered, the bending moment distribution of the top pillar corresponding to the second-step stope is the same as that of the two stopes during the first-step mining. At this time, the maximum positive bending moment is on both sides of the stope, which is 5.91 MN·m, and the maximum negative bending moment is in the middle of the stope, which is -2.953 MN·m. When considering the deformation of the filling body, the increase in the bending moment on both sides of the second-step stope caused by the mining of the second-step stope is small, while the maximum negative bending moment in the middle of the stope is -10.2 MN·m. By superimposing the bending moments of the first-step mining and the second-step mining, it can be seen that the maximum bending moment occurs at the edge of the panel, which is 12.2 MN·m, and the absolute values of both the positive and negative bending moments are significantly higher than those without considering the deformation of the filling body.

[0130] For the case without considering the filling body, the deflection of the top pillar decreases exponentially with the increase of its thickness. When considering the filling body, the decrease amplitude of the deflection of the top pillar with the increase of the thickness of the top pillar is not obvious, and the position of the maximum deflection of the panel top pillar gradually moves from the second-step stope to the middle of the panel. The support provided by the filling body in the middle of the panel is higher than that on both sides. Therefore, appropriately improving the quality of the middle filling body can improve the stress condition of the top pillar. The bending moment of the top pillar gradually increases with the increase of the thickness, but the normal stress of the cross-section gradually decreases in the second-step stope and gradually increases at the edge of the panel, and the increasing amplitude becomes smaller and smaller. In view of the fact that the proportion of the supporting force of the filling to resist deformation gradually decreases with the increase of the thickness of the top pillar, the maximum normal stress of the cross-section will decrease after increasing to a certain value.

[0131] Regarding the determination of the safety thickness of the boundary top pillar, when studying the open-pit to underground mining of Xujia Gully Iron Mine in Panzhihua, Sichuan, the tensile strength of the top pillar rock mass is 0.8 MPa, and the safety factor is taken as 2, that is, the allowable tensile strength of the top pillar is taken as 0.4 MPa. The safety thickness of the boundary top pillar is obtained by interpolation method as 27.3 m. At this time, the maximum tensile stress of the top pillar in the second-step stope is located on the lower surface at the position of x = 12.38 m of the top pillar. As a comparison, if the filling body is regarded as bedrock, that is, the deformation of the filling body is not considered, the safety thickness of the top pillar can be obtained as 8.86 m. In this way, it can be shown that when considering the deformation of the filling body, the required safety thickness of the boundary top pillar increases significantly, indicating that the deformation of the filling body has an important impact on the stability of the top pillar, and the filling body cannot be simply regarded as rigid bedrock for treatment.

[0132] The method, device and medium for determining the thickness of the top pillar of the open stoping with subsequent filling mining method provided in the embodiments of the present disclosure comprehensively consider the structural information of the mining field, that is, the division and size information of the top pillar, the filling body area and the stope area, and the characteristics of the top pillar as a combined structure of elastic foundation beam - ordinary beam - elastic foundation beam. By constructing the target equation about the filling body area and the stope area, setting the corresponding constraint conditions, and calculating the thickness of the top pillar in the open stoping with subsequent filling mining method, the safety of the mining operation is effectively improved, the safety accidents that may be caused by inappropriate thickness of the top pillar are avoided, and the resource utilization rate is optimized.

[0133] Those skilled in the art can understand that in the above methods of the specific embodiments, the writing order of each step does not mean a strict execution order and does not impose any limitation on the implementation process. The specific execution order of each step should be determined according to its function and possible internal logic.

[0134] Based on the same inventive concept, an apparatus for determining the thickness of the crown pillar in the open stoping and subsequent backfilling mining method is also provided in the embodiments of the present disclosure. Since the principle of solving problems by the apparatus in the embodiments of the present disclosure is similar to the method for determining the thickness of the crown pillar in the above open stoping and subsequent backfilling mining method of the embodiments of the present disclosure, the implementation of the apparatus can refer to the implementation of the method, and the repeated parts will not be described again.

[0135] Referring to Figure 4 As shown, it is a schematic diagram of an apparatus 400 for determining the thickness of the crown pillar in the open stoping and subsequent backfilling mining method provided by the embodiments of the present disclosure. The apparatus includes:

[0136] An information acquisition module 401, configured to acquire the structural information of the mining field; wherein, the structural information includes the mining field area information and the mining field area size information, and the mining field area information includes the crown pillar, the filling body area and the stope area; the crown pillar is located above the filling body area and the stope area, and the structure of the crown pillar includes a combined structure of an elastic foundation beam - ordinary beam - elastic foundation beam.

[0137] An equation construction module 402, configured to construct a target equation for the filling body area and the stope area and constraint conditions for the target equation.

[0138] A thickness determination module 403, configured to determine the thickness of the crown pillar based on the target equation, the constraint conditions and the mining field area size information.

[0139] In some possible embodiments, the filling body area includes a first filling body area and a second filling body area, wherein the first filling body area and the second filling body area are respectively distributed at both ends of the stope area.

[0140] In some possible embodiments, the mining field area size information includes filling body area information, stope area information and crown pillar information;

[0141] The target equation includes:

[0142]

[0143] wherein, E represents the elastic modulus of the filling body in the filling body area; I represents the moment of inertia of the crown pillar cross-section; k represents the coefficient of subgrade reaction; w(x) represents the deflection at position x; The dimensional information represented as the first filling body area; l 2 The dimensional information represented as the stope area; q represents the load borne by the upper part of the crown pillar, l 1 The dimensional information represented as the second filling body area.

[0144] In some possible embodiments, the constraint conditions include:

[0145]

[0146] Wherein, w 1 Represents the deflection at the position of the ordinary beam crown pillar above the first filling body area; w 2 Represents the deflection at the position of the elastic foundation beam crown pillar above the stope area; w 3 Represents the deflection at the position of the ordinary beam crown pillar above the second filling body area.

[0147] In some possible embodiments, the thickness determination module 403 is specifically configured to:

[0148] Determine the deflection of the crown pillar based on the target equation and the constraint conditions;

[0149] Solve for the crown pillar variable value of the mining field based on the deflection of the crown pillar and the crown pillar variable expression; wherein, the crown pillar variable expression includes a bending moment variable expression; the crown pillar variable value includes the maximum bending moment value;

[0150] Obtain the tensile strength of the crown pillar, and determine the thickness of the crown pillar based on the tensile strength and the maximum bending moment value.

[0151] In some possible embodiments, the bending moment variable expression includes:

[0152]

[0153] Wherein, M(x) represents the bending moment value at position x.

[0154] In some possible embodiments, the thickness determination module 403 is specifically configured to:

[0155] Determine the thickness of the crown pillar based on the thickness calculation formula, the tensile strength and the maximum bending moment value;

[0156] The thickness calculation formula includes:

[0157]

[0158] Wherein, h represents the thickness of the crown pillar; M represents the maximum bending moment value; σ represents the tensile strength of the crown pillar.

[0159] Based on the same inventive concept, embodiments of the present disclosure also provide a computer device. Refer to Figure 5 As shown, it is a schematic structural diagram of a computer device 500 provided by an embodiment of the present disclosure, including a processor 501, a memory 502, and a bus 503. Among them, the memory 502 is used to store execution instructions, including an internal memory 5021 and an external memory 5022; the internal memory 5021 here is also called the main memory, which is used to temporarily store the operation data in the processor 501 and the data exchanged with the external memory 5022 such as a hard disk, and the processor 501 exchanges data with the external memory 5022 through the internal memory 5021.

[0160] In an embodiment of the present application, the memory 502 is specifically used to store the application program code for implementing the solution of the present application and is controlled by the processor 501 to execute. That is, when the computer device 500 runs, the processor 501 communicates with the memory 502 through the bus 503, so that the processor 501 executes the application program code stored in the memory 502, and further executes the method described in any of the foregoing embodiments.

[0161] Among them, the memory 502 may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc.

[0162] The processor 501 may be an integrated circuit chip with the ability to process signals. The above-mentioned processor may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0163] It can be understood that the structure schematically shown in the embodiments of the present application does not constitute a specific limitation on the computer device 500. In other embodiments of the present application, the computer device 500 may include more or fewer components than those shown in the figure, or combine certain components, or split certain components, or have different component arrangements. The components shown in the figure can be implemented in hardware, software, or a combination of software and hardware.

[0164] The embodiments of the present disclosure also provide a computer-readable storage medium, on which a computer program is stored. When the computer program is run by a processor, it executes the steps of the method for determining the thickness of the crown pillar in the open stoping and subsequent backfilling mining method described in the above method embodiments. Among them, the storage medium may be a volatile or non-volatile computer-readable storage medium.

[0165] The embodiments of the present disclosure also provide a computer program product, which carries program code. The instructions included in the program code can be used to execute the steps of the method for determining the thickness of the crown pillar in the open stoping and subsequent backfilling mining method described in the above method embodiments. For details, refer to the above method embodiments and will not be elaborated here.

[0166] Among them, the above computer program product can be specifically implemented in the form of hardware, software, or a combination thereof. In an alternative embodiment, the computer program product is specifically embodied as a computer storage medium. In another alternative embodiment, the computer program product is specifically embodied as a software product, such as a Software Development Kit (SDK), etc.

[0167] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems and devices described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein. In several embodiments provided in the present disclosure, it should be understood that the disclosed systems and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some communication interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0168] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0169] In addition, in each embodiment of the present disclosure, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0170] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present disclosure, in essence, or the part that contributes to the prior art or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present disclosure. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs that can store program codes.

[0171] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present disclosure, used to illustrate the technical solutions of the present disclosure, rather than limiting them. The protection scope of the present disclosure is not limited thereto. Although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the art within the technical scope disclosed by the present disclosure can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and should all be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A method for determining the thickness of the top pillar in an open-pit subsequent filling mining method, characterized in that: include: Acquire structural information of a mining field; wherein the structural information includes mining field area information and mining field area size information, and the mining field area information includes a top column, a filling body area, and a mining field area; the top column is located above the filling body area and the mining field area, and the structure of the top column includes a combination structure of an elastic foundation beam-a common beam-an elastic foundation beam; Constructing a target equation about the filling body area and the stope area and constraints for the target equation; The thickness of the top pillar is determined based on the objective equation, the constraint conditions, and the mine area size information.

2. The method according to claim 1, characterized in that The filling body area includes a first filling body area and a second filling body area, wherein the first filling body area and the second filling body area are respectively distributed at two ends of the stope area.

3. The method according to claim 2, characterized in that The mining field area size information includes filling body area information, stope area information and top pillar information; The objective equation includes: Wherein, E represents the elastic modulus of the filling body in the filling body area; I represents the moment of inertia of the top column section; k represents the foundation reaction coefficient; w(x) represents the deflection at position x; It represents the size information of the first filling area; l2 represents the size information of the mining area; q represents the load borne by the upper part of the top column, and l1 represents the size information of the second filling area.

4. The method according to claim 3, characterized in that The constraints include: Among them, w1 represents the deflection of the top column position of the elastic foundation beam on the first filling body area; w2 represents the deflection of the top column position of the ordinary beam on the top of the mining area; w3 represents the deflection of the top column position of the elastic foundation beam on the second filling body area.

5. The method according to claim 4, characterized in that The step of determining the thickness of the top pillar based on the objective equation, the constraint conditions and the mining area size information comprises: Determining the deflection of the top column based on the objective equation and the constraint conditions; Solving the top pillar variable value about the mining field based on the deflection of the top pillar and the top pillar variable expression; wherein the top pillar variable expression includes a bending moment variable expression; the top pillar variable value includes a maximum bending moment value; The tensile strength of the top column is obtained, and the thickness of the top column is determined based on the tensile strength and the maximum bending moment value.

6. The method according to claim 5, characterized in that The bending moment variable expression includes: Wherein, M(x) represents the bending moment value at position x.

7. The method according to claim 5, characterized in that The step of determining the thickness of the top column based on the tensile strength and the maximum bending moment value comprises: Determining the thickness of the top column based on a thickness calculation formula, the tensile strength and the maximum bending moment value; The thickness calculation formula includes: Among them, h represents the thickness of the top column; M represents the maximum bending moment value; σ represents the tensile strength of the top column.

8. A device for determining the thickness of the top pillar in an open-pit subsequent filling mining method, characterized in that: include: An information acquisition module is used to acquire structural information of a mining field; wherein the structural information includes mining field area information and mining field area size information, and the mining field area information includes a top column, a filling body area, and a mining field area; the top column is located above the filling body area and the mining field area, and the structure of the top column includes a combination structure of an elastic foundation beam-a common beam-an elastic foundation beam; An equation building module, used for building a target equation about the filling body area and the stope area and constraint conditions for the target equation; A thickness determination module is used to determine the thickness of the top pillar based on the target equation, the constraint conditions and the mining area size information.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. A computer device comprising a storage medium, a processor, and a computer program stored in the storage medium and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

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