A method for equivalent quantification of multiple mining in coal seam groups and a visualization system

Abstract

The invention provides a method for equivalent quantification of multiple mining effects in coal seam groups and a visualization system, including obtaining parameters of each coal seam and rock stratum; calculating the heights of the caving zone, fissure zone, bending subsidence zone and floor failure according to the coal seam mining height, and dividing the plastic expansion zone, elastic expansion zone and virgin rock stress zone; calculating the total amount of overlying rock unloading expansion in the plastic expansion zone during single mining according to the stress-strain relationship of caving rock mass; calculating the total amount of overlying rock unloading expansion in the elastic expansion zone during single mining according to Hooke's law; obtaining the total amount of overlying rock expansion during single mining; calculating the amount of strata separation during single mining; calculating the influence of multiple mining effects based on the occurrence characteristics of coal seam groups, coal seam mining height and the floor failure situation during single mining, and equivalent to the equivalent thickness of a single mining coal seam, and realizing visual display through a program. The invention takes into account the influence of multiple mining, obtains the equivalent mining thickness of the first mining layer under the action of multiple mining, realizes the equivalent quantification of the multiple mining effects in coal seam groups, and provides a certain basic support for gas extraction in close coal seam groups and outburst prevention in medium and long-distance coal seam groups.

Description

Technical Field

[0001] The present invention relates to the field of mine engineering, and particularly relates to a method for equivalent quantification of multiple mining-induced effects in coal seam groups and a visualization system. Background Art

[0002] The unloading and swelling effect of overlying strata has a significant impact on the prediction of the effective protection range of protective coal seams. At present, the unloading and swelling effect of overlying strata can be calculated through theoretical models, which is related to the coal seam mining height, but does not consider the occurrence characteristics of coal seam groups and the influence of multiple mining-induced effects on the unloading and swelling amount of overlying strata.

[0003] Pressure relief mining is still one of the important methods for gas control in coal seam group mining at present, and the mining of protective coal seams is even one of the economical and efficient methods for preventing coal and gas outbursts; one of the key issues involved is the quantification of pressure relief effect. Different from single mining, under the action of multiple mining-induced effects in coal seam groups, the protected coal seam is affected by multiple mining-induced effects, resulting in great differences in the characteristics of overlying strata displacement distribution, stress change, etc. in the protected coal seam compared with single protective coal seam mining. The quantification of pressure relief effect in single coal seam mining can no longer provide effective theoretical support for multi-coal seam pressure relief mining.

[0004] Therefore, there is an urgent need to develop a method for equivalent quantification of multiple mining-induced effects in coal seam groups. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for equivalent quantification of multiple mining-induced effects in coal seam groups and a visualization system to solve the problems existing in the prior art.

[0006] The first aspect of the present invention provides a method for equivalent quantification of multiple mining-induced effects in coal seam groups, including the following steps:

[0007] S1. Measure and obtain the parameters of each coal and rock layer, including the initial elastic modulus, initial tangent modulus, swelling coefficient, coal and rock unit weight, and compressive strength.

[0008] S2. Calculate the heights of the caving zone, fissure zone, bending subsidence zone, and floor failure according to the coal seam mining height, and divide the plastic swelling zone, elastic swelling zone, and original rock stress zone.

[0009] S3. Calculate the total amount of overlying strata unloading and swelling in the plastic swelling zone during single mining according to the stress-strain relationship of caving rock mass. And calculate the total amount of overlying strata unloading and swelling in the elastic swelling zone during single mining according to Hooke's law. Obtain the total amount of overlying strata swelling during single mining.

[0010] S4. Calculate and obtain the amount of strata separation during single mining according to steps S2 and S3.

[0011] S5. Calculate the influence of multiple mining-induced effects and equivalent it to the equivalent thickness of a single mining coal seam based on the occurrence characteristics of coal seam groups, coal seam mining height, and the floor failure situation during single mining.

[0012] As a preferred embodiment of the present application, optionally, in step S2, the calculation of the heights of the collapse zone, the fracture zone, the curved subsidence zone, and the floor failure according to the coal seam mining height includes:

[0013] Calculate the height of the collapse zone:

[0014]

[0015] Where H m is the height of the collapse zone, m. ∑M is the cumulative thickness of the mined coal seam, m.

[0016] Calculate the fracture zone height:

[0017]

[0018] Where H li is the height of the fracture zone, m. ∑M is the cumulative thickness of the mined coal seam, m.

[0019] Calculate the height of the curved depression:

[0020] H w =HH m -H li .

[0021] Where H w is the height of the curved subsidence zone, m.

[0022] Calculate the bottom plate failure height:

[0023] h=0.0085M+0.1665α+0.1079L-4.3579.

[0024] Where h is the floor failure height, m. M is the mining depth, taking the average working face mining depth, m. α is the formation dip, taking the average formation dip. L is the inclined length of the working face, m.

[0025] As a preferred embodiment of the present application, optionally, in step S3, the step of obtaining the total amount of overburden expansion caused by a single mining operation includes:

[0026] Set the stress-strain relationship of the collapsed rock mass:

[0027]

[0028] Where σ1 is the axial stress, Pa. ε1 is the axial strain. m1 is the maximum possible axial strain, which refers to the strain of the crushed coal rock relative to the original coal rock. E0 is the initial tangent modulus, Pa.

[0029] As a preferred implementation of this application, optionally, it further includes:

[0030] Calculate the overburden expansion amount within a single direction range:

[0031]

[0032] In the formula, f(y′) is the overburden expansion amount within the range of y, in m. l is the height of the plastic expansion zone, in m. is the bulking factor of coal and rock at a distance of y1 from the mining seam in the plastic expansion zone. is the unloading expansion factor of coal and rock at a distance of y2 from the mining seam in the elastic expansion zone. is the overburden expansion amount in the plastic expansion zone, in m. is the overburden expansion amount in the elastic expansion zone, in m.

[0033] Among them, the relationship between the bulking factor, unloading expansion factor and coal and rock load is as follows:

[0034]

[0035] In the formula, σ1 is the vertical stress in the plastic expansion zone, in Pa. K0 is the initial bulking factor. E0 is the initial tangent modulus, in Pa. σ2 is the vertical stress in the elastic expansion zone, in Pa. E is the elastic modulus, in Pa.

[0036] It further includes:

[0037] Calculate the total overburden expansion amount f1 for a single mining:

[0038] f1 = H k + G j - G r .

[0039] In the formula, H k is the total overburden expansion amount in the plastic expansion zone, in m. G j is the total overburden expansion amount in the elastic expansion zone, in m. G r is the total overburden expansion amount in the elastic expansion zone of the floor, in m.

[0040] As a preferred implementation of this application, optionally, in step S4, the calculation and acquisition of the separation amount of the rock stratum for a single mining according to steps S2 and S3 are specifically as follows:

[0041] δ1 = M1 - f1.

[0042] In the formula, M1 is the mining thickness of the coal seam for a single mining. f1 is the total unloading expansion amount of the overburden for a single mining.

[0043] As a preferred implementation of this application, optionally, the coal seam group occurrence characteristics include: close-distance, medium-distance and long-distance coal seam groups, among which,

[0044] The close coal seam group is defined as a coal seam group with a very close distance between multiple minable coal seams, having significant mutual influence during mining, and the caving zone can be conducted after mining.

[0045] The medium-distance coal seam group is defined as a coal seam group with a moderate distance between multiple minable coal seams, having a certain influence during mining, and the caving zone and fissure zone appear alternately after mining.

[0046] The long-distance coal seam group is defined as a coal seam group with a relatively far distance between multiple minable coal seams, having no significant influence during mining, and its "three zones" appear alternately after mining.

[0047] The above-mentioned based on the coal seam mining height includes calculating the mining distance between the upper protective layer and the lower protective layer, where:

[0048] The calculation formula for the mining of the upper protective layer is:

[0049] The equivalent relative layer spacing of the upper protective layer

[0050] The calculation formula for the mining of the lower protective layer is:

[0051] The equivalent relative layer spacing of the lower protective layer

[0052] In the formula, R is the equivalent relative layer spacing between the protective layer and the protected layer. R0 is the relative layer spacing between the protective layer and the protected layer. S is the vertical layer distance between the protective layer and the protected layer, in m. β α is the coal seam dip angle coefficient, α is the coal seam dip angle, in °. K is the roof control coefficient. β1 is the influence coefficient of the mining height of the protective layer. β2 is the coefficient of the hard rock content between layers. β3 is the floor failure coefficient of the upper protective layer mining. M is the mining thickness of the protective layer, in m.

[0053] As a preferred implementation scheme of the present application, optionally, in step S5, for the coal seam group mining, the calculation of the influence of multiple mining actions based on the occurrence characteristics of the coal seam group, the coal seam mining height, and the floor failure situation of a single mining and equivalent to the equivalent thickness of the single mining coal seam includes:

[0054] The influence of the secondary mining on the protected layer includes:

[0055] Calculating the total expansion amount of the overlying strata f2 during the secondary mining:

[0056] f2 = H k ′ + H r + G j ′ - G s .

[0057] In the formula, H k ′, H ris the total amount of swelling of the overlying strata in the plastic swelling area during secondary mining, m. G j ′ is the total amount of swelling of the overlying strata in the elastic swelling area during secondary mining, m. G s is the total amount of swelling of the overlying strata of the floor during secondary mining, m.

[0058] Calculate the separation amount δ2 of the overlying strata during secondary mining:

[0059] δ2 = M1 + M2 - f2.

[0060] In the formula, M2 is the coal seam thickness mined during secondary mining. f2 is the total amount of swelling of the overlying strata due to unloading.

[0061] The influence of tertiary mining on the protected seam includes:

[0062] Calculate the total amount of swelling f3 of the overlying strata during tertiary mining:

[0063] f3 = H k ″ + H r ′ + H s + G j ″ - G w .

[0064] In the formula, H k ″, H r ′, H s is the total amount of swelling of the overlying strata in the plastic swelling area during tertiary mining, m. G j ″ is the total amount of swelling of the overlying strata in the elastic swelling area during tertiary mining, m. G w is the total amount of swelling of the overlying strata of the floor during tertiary mining, m.

[0065] Calculate the separation amount δ3 of the strata during tertiary mining:

[0066] δ3 = M1 + M2 + M3 - f3.

[0067] In the formula, M3 is the coal seam thickness mined during tertiary mining. f3 is the total amount of swelling of the overlying strata due to unloading during tertiary mining.

[0068] According to the influence of the secondary mining and tertiary mining on the protected seam, calculate the equivalent thickness of the coal seam affected by multiple mining as equivalent to a single mining, including:

[0069] Calculate the equivalent thickness of the coal seam affected by the separation amount using the volume method, as shown in the following formula:

[0070]

[0071] In the formula, is the equivalent coal seam thickness of the separation amount, m. S g is the area between specific coal seam distances, m 2 . Ω is the separation volume of the upper protected coal seam, m 3, it is considered that the separation layer is a rectangular parallelepiped fitting model in three-dimensional space, and its calculation formula is: Where a is the length of the detached space model, m. b is the width of the detached space model, m. δ is the detached space amount, m.

[0072] As a preferred embodiment of the present application, optionally, it further includes:

[0073] The equivalent thickness of a single mining coal seam is calculated quantitatively based on the unloading expansion of the overburden rock, and is equivalent to the thickness of the first mining coal seam, including:

[0074] Calculate the thickness of the coal seam equivalent to the first mining layer after secondary mining as ΔM:

[0075]

[0076] Where, The equivalent coal seam thickness of single mining and secondary mining is m. δ1 and δ2 are the equivalent coal seam thickness of single mining and secondary mining, m.

[0077] Calculate the equivalent thickness of the first mining layer after three mining operations as ΔM′:

[0078]

[0079] Where, The equivalent coal seam thickness of the tertiary mining and secondary mining separation, respectively, is m. δ3 and δ2 are the tertiary mining and secondary mining separation, respectively, is m.

[0080] Furthermore, the thickness of the coal seam equivalent to the first mining layer after secondary mining is ΔM:

[0081]

[0082] Where H k is the total amount of overburden expansion in the plastic expansion zone during a single mining operation, m. G j G is the total amount of overburden expansion in the elastic expansion zone during a single mining operation, m. r H is the total amount of overburden expansion in the elastic expansion zone of the floor during a single mining operation, m. r ′、H r is the total amount of overburden expansion in the secondary mining plastic expansion zone, m. G j G′ is the total amount of overburden expansion in the elastic expansion zone of secondary mining, m. s is the total amount of expansion of the floor overburden due to secondary mining, m.

[0083] The equivalent thickness of the first mining layer after three mining operations is ΔM′:

[0084]

[0085] Where H k″, H r ′, H s is the total amount of overlying strata expansion in the plastic expansion zone during the third mining, m. G j ″ is the total amount of overlying strata expansion in the elastic expansion zone during the third mining, m. G w is the total amount of overlying strata expansion in the floor during the third mining, m.

[0086] Furthermore, the equivalent coal seam thickness of the second mining to the first mining seam is ΔM:

[0087]

[0088] In the formula, H k is the total amount of overlying strata expansion in the plastic expansion zone during a single mining, m. G j is the total amount of overlying strata expansion in the elastic expansion zone during a single mining, m. H k ′, H d is the total amount of overlying strata expansion in the plastic expansion zone during the second mining, m. G j ′, G c is the total amount of overlying strata expansion in the elastic expansion zone during the second mining, m.

[0089] The equivalent coal seam thickness of the third mining to the first mining seam is ΔM′:

[0090]

[0091] In the formula, H k ″, H d ′, H b is the total amount of overlying strata expansion in the plastic expansion zone during the third mining, m. G j ″, G c ′, G a is the total amount of overlying strata expansion in the elastic expansion zone during the third mining, m.

[0092] The second aspect of the present invention also provides a visualization system, including:

[0093] The equivalent quantification visualization system for multiple mining of coal seam groups, after inputting initial coal seam and rock stratum parameters and data such as mining thickness, through the computer program of the memory and processor, processes data according to instructions, and both the intermediate results and the final results are displayed on the display interface, including: the expansion amount of overlying strata in the elastic expansion zone, the expansion amount of overlying strata in the plastic expansion zone, the total expansion amount of overlying strata, the separation amount, and the equivalent thickness. Changing the input parameter data, the calculation results also change in real time.

[0094] And,

[0095] A memory for storing executable instructions.

[0096] A processor for calculating data processing instructions.

[0097] A screen for parameter input and calculation result display.

[0098] The memory is used to store a computer program for any one of the above-described equivalent quantification methods for multiple mining actions of coal seam groups.

[0099] The processor is configured to implement an equivalent quantification method for multiple mining actions of a coal seam group when executing the computer program.

[0100] The screen is configured to display a parameter input interface and a calculation result interface.

[0101] Technical effects of the present invention:

[0102] A. The present invention fully considers the influence of multiple mining actions and the floor failure situation, classifies the coal seam groups according to the occurrence characteristics of the coal seam groups, and makes a certain expansion and innovation to the existing classification standards for near and far-distance coal seam groups.

[0103] B. Compared with the previous method for calculating the overburden unloading and swelling amount that only considered single mining, the method provided by the present invention obtains a more accurate amount of overburden separation for multiple mining actions of coal seam groups according to the occurrence characteristics of the coal seam groups, ensuring the authenticity and objectivity of the influence range of multiple protective layer mining on the upper protected coal seam.

[0104] C. The method provided by the present invention can obtain the equivalent mining thickness of the multiple mining actions of the coal seam group equivalent to the first mined coal seam, realizing the equivalent quantification of the mining action in the process of changing from single mining to multiple mining of the coal seam group.

[0105] D. The method provided by the present invention provides a certain theoretical basis for gas extraction in near-distance coal seam groups and outburst prevention in medium and far-distance coal seam groups.

[0106] E. The equivalent quantification visualization system for multiple mining actions of coal seam groups provided by the present invention can realize transparent data throughout the equivalent quantification process, clear calculation process, and prominent display of single or multiple equivalent quantification results; it can display data changes and the dynamic process of real-time update of calculation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0107] The drawings included in and constituting a part of the specification, together with the specification, illustrate the exemplary embodiments, features, and aspects of the present disclosure and are used to explain the principles of the present disclosure.

[0108] Figure 1 It is a schematic flow chart of the implementation process of an equivalent quantification method for multiple mining actions of a coal seam group of the present invention;

[0109] Figure 2 For the present invention Figure 1 The specific implementation schematic flow chart of the method;

[0110] Figure 3Schematic diagram of the multiple mining theory model for close coal seam groups;

[0111] Figure 4 Schematic diagram of the multiple mining of close coal seam groups;

[0112] Figure 5 Schematic diagrams of the multiple mining of medium-distance coal seam groups and the theoretical model;

[0113] Figure 6 Schematic diagram of the multiple mining of long-distance coal seam groups. Specific implementation manners

[0114] The present invention will be further described below in conjunction with embodiments, but it should not be understood that the above-mentioned subject matter scope of the present invention is limited to the following embodiments. Without departing from the above-mentioned technical idea of the present invention, various substitutions and changes made according to the common general knowledge and conventional means in the art shall be included within the protection scope of the present invention. The various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0115] The special term "exemplary" here means "serving as an example, embodiment or illustrative". Any embodiment described as "exemplary" here does not have to be construed as superior to or better than other embodiments.

[0116] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific implementation manners. Those skilled in the art should understand that the present disclosure can also be implemented without some specific details. In some instances, methods, means, elements and circuits well-known to those skilled in the art are not described in detail in order to highlight the gist of the present disclosure.

[0117] Embodiment 1:

[0118] See Figure 1 , which is a schematic diagram of the implementation process of the present invention, discloses a method for equivalent quantification of multiple mining of coal seam groups, including the following steps:

[0119] S1. Measure and obtain the parameters of each coal and rock layer, including the initial elastic modulus, initial tangent modulus, bulking coefficient, coal and rock unit weight, and compressive strength;

[0120] S2. Calculate the heights of the caving zone, fissure zone, bending subsidence zone and floor failure according to the coal seam mining height, and divide the plastic expansion zone, elastic expansion zone and virgin stress zone;

[0121] S3. Calculate the total amount of unloading expansion of the overlying strata in the plastic expansion zone during a single mining operation according to the stress-strain relationship of the caving rock mass; and calculate the total amount of unloading expansion of the overlying strata in the elastic expansion zone during a single mining operation according to Hooke's law; obtain the total amount of overlying strata expansion during a single mining operation.

[0122] S4. Calculate and obtain the amount of strata separation during a single mining operation according to steps S2 and S3.

[0123] S5. Calculate the influence of multiple mining operations based on the occurrence characteristics of coal seam groups, the mining height of coal seams, and the floor failure situation during a single mining operation, and equivalent it to the equivalent thickness of a single mining coal seam.

[0124] See Figure 2 , which is the implementation flowchart for the specific implementation of the above process.

[0125] In view of the problem of insufficient quantification of multiple mining effects in close-distance coal seam groups, this embodiment provides a method for equivalent quantification of multiple mining effects in coal seam groups, including the following steps:

[0126] Measure parameters such as the initial elastic modulus, initial tangent modulus, bulking coefficient, coal and rock unit weight, and compressive strength of each coal and rock stratum. Assume that the lithology of each stratum is similar, with little difference, and the influence of key strata is not considered. Assume that strata separation occurs below the protected coal seam, and the protected coal seam is in the bending subsidence zone, and the occurrence mode of the coal seam group is a close-distance coal seam group.

[0127] In this embodiment, the upper protected coal seam is preferentially mined, that is, the coal seam mining sequence in the close-distance coal seam group is 2# → 3# → 4#, as Figure 3 and Figure 4 shown.

[0128] As a preferred implementation scheme of this application, optionally, in step S2, the calculation of the heights of the caving zone, fissure zone, bending subsidence zone, and floor failure according to the mining height of the coal seam includes:

[0129] 1) The calculation formula for the height of the caving zone:

[0130]

[0131] In the formula, H m is the height of the caving zone, m; ∑M is the cumulative thickness of the mined coal seams, m.

[0132] The calculation formula for the height of the fissure zone:

[0133]

[0134] In the formula, H li is the height of the caving zone, m; ∑M is the cumulative thickness of the mined coal seams, m.

[0135] The calculation formula for the height of the bending subsidence zone:

[0136] H w = H-H m -H li (3)

[0137] In the formula, H w is the height of the caving zone, m.

[0138] Calculation formula for the height of floor damage:

[0139] h = 0.0085M + 0.1665α + 0.1079L - 4.3579 (4)

[0140] In the formula, h is the height of floor damage, m; M is the mining depth, taking the average mining depth of the working face, m; α is the formation dip angle, taking the average formation dip angle; L is the inclined length of the working face, m.

[0141] Among them, in step S2, the zoning principle for dividing the plastic expansion zone, elastic expansion zone and virgin rock stress zone is as follows:

[0142] After the overlying rock in the caving zone collapses, the coal and rock are broken and expanded, showing a loose accumulation state. The deformation of the swollen coal and rock caused by the overlying load is irreversible and is plastic deformation. Therefore, the caving zone is considered as the plastic expansion zone;

[0143] In the fissure zone, the coal and rock strata are bent and fractured. The fracture blocks of the overlying rock are relatively large and are basically arranged regularly; and the coal and rock mass in the bending subsidence zone basically remains intact. Therefore, the unloaded coal and rock strata in the fissure zone and the bending subsidence zone are considered as the elastic expansion zone;

[0144] The rock strata from the protected coal seam to the ground surface are divided into the virgin rock stress zone (weak expansion zone).

[0145] As a preferred implementation method of this application, optionally, in step S3, according to the stress-strain relationship of the caving rock mass, calculate the total amount of unloading expansion of the overlying rock in the plastic expansion zone during a single mining;

[0146] According to Hooke's law, calculate the total amount of unloading expansion of the overlying rock in the elastic expansion zone during a single mining; finally obtain the total amount of overlying rock expansion during a single mining; including:

[0147] 1) Set the stress-strain relationship of the caving rock mass:

[0148] Assume that the coal and rock in the fissure zone are regarded as elastic bodies and follow the generalized Hooke's law; assume that the caved coal and rock in the caving zone follow the deformation law of fractured rock masses; stress-strain relationship of the caving rock mass:

[0149] [[ID=4⑨]]

[0150] In formula (5), σ1 is the axial stress, Pa; ε1 is the axial strain; ε m1is the maximum possible axial strain, which refers to the strain of the swollen coal and rock relative to the original coal and rock; E0 is the initial tangent modulus, Pa.

[0151] 2) Calculate the total amount of overlying strata swelling f1 caused by a single mining:

[0152]

[0153] In formula (6), H k is the total amount of overlying strata swelling in the plastic swelling zone, m; G j is the total amount of overlying strata swelling in the elastic swelling zone, m; G r is the total amount of overlying strata swelling in the elastic swelling zone of the floor, m; is the initial tangent modulus of the plastic swelling zone, Pa; is the swelling coefficient of the caving coal and rock; is the unloading swelling coefficient of the coal and rock; R k 、R j 、R r are the coal and rock loads from the upper interfaces of the k-th, j-th, and r-th rock layers to the range of y′; is the unit weight of the coal and rock, N / m 3 ; E j 、E r are the elastic moduli of the elastic swelling zone, Pa.

[0154] As a preferred implementation method of this application, further, according to step 1) and step 2), calculate the separation amount δ1 of the strata caused by a single mining.

[0155] δ1 = M1 - f1 = M1 - (H k + G j - G r ) In formula (7), M1 is the mining thickness of the 2# coal seam caused by a single mining; f1 is the total amount of overlying strata unloading swelling.

[0156]

[0157] As a preferred implementation method of this application, optionally, in step S3, according to the stress-strain relationship of the caving rock mass, calculate the total amount of overlying strata unloading swelling in the plastic swelling zone caused by a single mining;

[0158] According to Hooke's law, calculate the total amount of overlying strata unloading swelling in the elastic swelling zone caused by a single mining; finally, obtain the total amount of overlying strata swelling caused by a single mining; it may further include:

[0159] Calculate the overlying strata swelling amount within a single direction range:

[0160]

[0161] ​In the formula, f(y′) is the amount of overburden expansion within the range of y, in m; l is the height of the plastic expansion zone, in m; is the coefficient of coal and rock dilatancy at a distance of y1 from the mining seam in the plastic expansion zone; is the coefficient of coal and rock unloading expansion at a distance of y2 from the mining seam in the elastic expansion zone; is the amount of overburden expansion in the plastic expansion zone, in m; is the amount of overburden expansion in the elastic expansion zone, in m;

[0162] Among them, the relationships between the dilatancy coefficient, unloading expansion coefficient and coal and rock load are as follows:

[0163]

[0164] In the formula, σ1 is the vertical stress in the plastic expansion zone, in Pa; K0 is the initial dilatancy coefficient; E0 is the initial tangent modulus, in Pa; σ2 is the vertical stress in the elastic expansion zone, in Pa; E is the elastic modulus, in Pa.

[0165] This embodiment only describes the calculation of the amount of overburden expansion within the y - direction range, not limited to the y - direction only, and can be set by the user himself.

[0166] As a preferred implementation method of this application, optionally, in step S5, considering the occurrence characteristics of coal seam groups, they are divided into three types of coal seam groups, namely, close - distance, medium - distance, and long - distance coal seam groups. Among them, as shown in the appendix Figure 3 shown

[0167] The close - distance coal seam group is generally considered as a coal seam group with very close seam spacings of multiple minable coal seams, having significant mutual influence during mining, and the caving zone can conduct after mining;

[0168] The long - distance coal seam group is generally considered as a coal seam group with relatively far seam spacings between multiple minable coal seams, having no significant influence during mining, and its "three zones" appear alternately after mining;

[0169] Therefore, the medium - distance coal seam group can be considered as a coal seam group with moderate seam spacings of multiple minable coal seams, having a certain influence during mining, and its caving zone and fracture zone appear alternately after mining.

[0170] The said calculation according to the coal seam mining height includes calculating the mining spacings of the upper protective layer and the lower protective layer, where:

[0171] For the calculation of lower protective layer mining:

[0172] For the calculation of upper protective layer mining:

[0173] Wherein, R is the equivalent relative layer spacing between the protective layer and the protected layer; R0 is the relative layer spacing between the protective layer and the protected layer; S is the vertical layer spacing between the protective layer and the protected layer, m; β α is the coal seam dip angle coefficient, α is the coal seam dip angle, °; K is the roof management coefficient; β1 is the influence coefficient of the mining height of the protective layer; β2 is the coefficient of the hard rock content between layers; β3 is the floor failure coefficient of the upper protective layer mining; M is the mining thickness of the protective layer, m; M0 is the minimum effective thickness of the protective layer, m.

[0174] Therefore, the classification and characteristics of coal seam groups are shown in the following table:

[0175]

[0176] In this embodiment, for the mining of close coal seam groups, the calculation of the equivalent thickness of the coal seam under single mining is specifically described as follows:

[0177] As a preferred implementation of the present application, optionally, in step S5, for the mining of close coal seam groups, calculating the influence of multiple mining actions and equivalent to the equivalent thickness of the coal seam under single mining based on the occurrence characteristics of the coal seam group, the mining height of the coal seam, and the floor failure situation under single mining, includes:

[0178] The influence of secondary mining on the protected layer includes:

[0179] Considering the occurrence characteristics of the coal seam group, the mining height of the coal seam, and the floor failure situation under single mining, calculate the "three zones" height of secondary mining, and calculate the total amount of overburden expansion and the amount of overburden separation during secondary mining.

[0180] Calculate the total amount of overburden expansion f2 during secondary mining:

[0181]

[0182] Wherein, H k ′, H r is the total amount of overburden expansion in the plastic expansion zone during secondary mining, m; G j ′ is the total amount of overburden expansion in the elastic expansion zone during secondary mining, m; G s is the total amount of overburden expansion in the floor of secondary mining, m.

[0183] As Figure 4 shown, the caving zone formed by secondary mining coincides with the caving zone formed by single mining. At this time, the height of the plastic expansion zone is approximately equal to the sum of the height of the caving zone formed by single mining and the layer spacing of the lower coal seam.

[0184] Calculate the height of the fissure zone and the bending subsidence zone according to the cumulative mining height, and divide the elastic expansion zone and the weak expansion zone.

[0185] Calculate the amount of overburden separation δ2 during secondary mining:

[0186] δ2 = M1 + M2 - f2 = M1 + M2 - (H k ′ + H r + G j ′ - G s )(9)

[0187] Wherein, M2 is the mining thickness of the 3# coal seam in the secondary mining; f2 is the total amount of overburden unloading and swelling.

[0188] Influence of the third mining on the protected coal seam:

[0189] Considering the occurrence characteristics of coal seam groups, coal seam mining height, and the floor failure situation in the secondary mining, calculate the height of the "three zones" in the third mining. Calculate the total amount of overburden swelling and the amount of overburden separation in the third mining.

[0190] Calculate the total amount of overburden swelling f3 in the third mining:

[0191]

[0192] Wherein, H k ″, H r ′, H s is the total amount of overburden swelling in the plastic swelling zone of the third mining, m; G j ″ is the total amount of overburden swelling in the elastic swelling zone of the third mining, m; G w is the total amount of overburden swelling in the floor of the third mining, m.

[0193] Calculate the amount of strata separation δ3 in the third mining:

[0194] δ3 = M1 + M2 + M3 - f3 = M1 + M2 + M3 - (H k ″ + H r ′ + H s + G j ″ - G w )(11)

[0195] Wherein, M3 is the mining thickness of the 4# coal seam in the third mining; f3 is the total amount of overburden unloading and swelling.

[0196] As a preferred implementation scheme of the present application, optionally, after obtaining the influence of the secondary mining and the third mining on the protected coal seam,

[0197] It further includes: calculating the equivalent thickness of the coal seam with the influence of multiple mining actions equivalent to a single mining, and calculating the equivalent thickness of the coal seam with the influence of strata separation by the volume method, as shown in the following formula:

[0198]

[0199] Wherein, is the equivalent thickness of the coal seam with strata separation, m; S gThe area between specific coal seam distances, m 2 ; Ω is the separated layer volume of the upper protected coal seam, m 3 , and it is considered that the separated layer is a cuboid fitting model in three-dimensional space, and its calculation formula is where a is the length of the separated layer space model, m, b is the width of the separated layer space model, m; δ is the amount of separated layer, m.

[0200] Finally, the equivalent quantization of multiple mining in close coal seam groups based on overburden unloading expansion is obtained:

[0201] The equivalent thickness of the second mining to the first mining coal seam is ΔM:

[0202]

[0203] In the formula, H k is the total overburden expansion in the plastic expansion zone of single mining; G j is the total overburden expansion in the elastic expansion zone of single mining; G r is the total overburden expansion in the elastic expansion zone of the floor of single mining; H k ′, H r is the total overburden expansion in the plastic expansion zone of the second mining; G j ′ is the total overburden expansion in the elastic expansion zone of the second mining; G s is the total overburden expansion of the floor of the second mining; M2 is the coal thickness of the second mining coal seam;

[0204] The equivalent thickness of the third mining to the first mining coal seam is ΔM′:

[0205]

[0206] In the formula, H k ″, H d ′, H b is the total overburden expansion in the plastic expansion zone of the third mining, m; G j ″, G c ′, G a is the total overburden expansion in the elastic expansion zone of the third mining, m.

[0207] The equivalent thickness of the third mining to the first mining coal seam is ΔM′:

[0208]

[0209] In the formula, H k ″, H r ′, H s is the total overburden expansion in the plastic expansion zone of the third mining, m; G j ″ is the total overburden expansion in the elastic expansion zone of the third mining, m; G w is the total overburden expansion of the floor of the third mining, m.

[0210] The specific input parameters of the above embodiments are input by the user after measuring the basic data, and are calculated according to the process through system calculation. The parameter setting can be set by the user.

[0211] The present invention fully considers the influence of multiple mining activities and the floor failure situation, classifies the coal seam groups according to the occurrence characteristics of the coal seam groups, and expands and innovates the existing classification criteria for near and far-distance coal seam groups to a certain extent;

[0212] Compared with the previous calculation method of the overburden unloading expansion amount that only considered single mining, the method provided by the present invention obtains more accurate strata separation amounts of multiple mining of coal seam groups for the occurrence characteristics of coal seam groups, ensuring the authenticity and objectivity of the influence range of multiple protective layer mining on the upper protected coal seam;

[0213] The method provided by the present invention can obtain the equivalent mining thickness of multiple mining of coal seam groups equivalent to the first mined coal seam, realizing the equivalent quantification of the mining effect during the process of single mining to multiple mining of coal seam groups.

[0214] Although the above embodiments are calculated for three mining operations of different coal seams, the present technology does not limit the number of coal seams provided in this embodiment and the drawings, and different coal seams can be selected for calculation in combination with different scenarios.

[0215] Embodiment 2:

[0216] Based on the embodiments, this embodiment provides the equivalent thickness of the single mined coal seam for medium and far-distance coal seam groups, the mining method is upward mining, and the equivalent quantification calculation is as follows:

[0217] The main steps of this embodiment are the same as those of Embodiment 1 and will not be described here. In addition, since the influence of the floor of medium and far-distance coal seam groups on the total overburden expansion is small, the floor influence is not considered in this embodiment.

[0218] This embodiment is for medium and far-distance coal seam groups, see Figure 5 And Figure 6 , the mining sequence is 4# → 3# → 2#.

[0219] The strata separation amount of single mining is:

[0220] δ1 = M1 - H k - G j (1)

[0221] The strata separation amount of secondary mining is:

[0222] δ2 = M1 + M2 - H k ′ - G j ′ - H d - G c (2)

[0223] The amount of separated strata in the overlying strata during the tertiary mining is:

[0224] δ3 = M1 + M2 + M3 - H k ″ - G j ″ - H d ′ - G c ′ - H b - G a (3)

[0225] Finally, the equivalent quantification of multiple mining in medium - and long - distance coal seam groups is obtained:

[0226] The equivalent coal seam thickness of the secondary mining to the first - mined seam is ΔM:

[0227]

[0228] In the formula, H k is the total expansion of the overlying strata in the plastic expansion zone during single - mining, m; G j is the total expansion of the overlying strata in the elastic expansion zone during single - mining, m; H k ′, H d is the total expansion of the overlying strata in the plastic expansion zone during secondary mining, m; G j ′, G c is the total expansion of the overlying strata in the elastic expansion zone during secondary mining, m.

[0229] The equivalent coal seam thickness of the tertiary mining to the first - mined seam is ΔM′:

[0230]

[0231] In the formula, H k ″, H d ′, H b is the total expansion of the overlying strata in the plastic expansion zone during tertiary mining, m; G j ″, G c ′, G a is the total expansion of the overlying strata in the elastic expansion zone during tertiary mining, m.

[0232] The above - mentioned embodiment can adopt the visualization system of the following embodiment. The specific parameter input is entered by the user after measuring the basic data. After the process calculation of the visualization system, the process setting can be set by the user according to the needs.

[0233] Embodiment 3

[0234] The second aspect of the present invention also provides a visualization system, including:

[0235] The multiple mining equivalent quantification visualization system for coal seam groups, after inputting data such as initial coal and rock layer parameters and mining thickness, through the computer program of the memory and the processor, processes the data according to instructions, and both the intermediate results and the final results of the processing are displayed on the display interface, including: the overburden expansion amount in the elastic expansion zone, the overburden expansion amount in the plastic expansion zone, the total overburden expansion amount, the separation amount, and the equivalent thickness; when the input parameter data is changed, the calculation results also change in real time;

[0236] And,

[0237] A memory for storing executable instructions;

[0238] A processor for calculating data processing instructions;

[0239] A screen for parameter input and calculation result display;

[0240] The memory is used to store the computer program for implementing a method for equivalent quantification of multiple mining of coal seam groups provided in Embodiment 1;

[0241] The processor is configured to implement a method for equivalent quantification of multiple mining of coal seam groups described in Embodiment 1 or 2 when executing the computer program,

[0242] The screen is configured to display a parameter input interface and a calculation result interface.

[0243] The visualization system of the present disclosure embodiment includes a processor, a memory for storing processor-executable instructions, and a screen for displaying parameters and results. Among them, the processor is configured to implement a method for equivalent quantification of multiple mining of coal seam groups described in any one of the foregoing when executing the executable instructions.

[0244] Here, it should be noted that the number of processors can be one or more. At the same time, in the visualization system of the present disclosure embodiment, an input device and an output device may also be included. Among them, the processor, the memory, the input device, and the output device can be connected through a bus or in other ways, which is not specifically limited here.

[0245] As a computer-readable storage medium, the memory can be used to store software programs, computer-executable programs, and various modules, such as: the program or module corresponding to a method for equivalent quantification of multiple mining of coal seam groups in the present disclosure embodiment. The processor executes various functional applications and data processing of the visualization system by running the software programs or modules stored in the memory.

[0246] The input device can be used to receive input numbers or signals. Among them, the signal can be a signal related to the user settings and function visualization of the device / terminal / server. The output device can include devices such as a computer with more powerful display functions and better visualization effects.

[0247] The embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technologies in the market, or to enable other ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for equivalent quantification of multiple mining in coal seam groups, characterized in that It includes the following steps: S1. Measure and obtain various coal seam and rock layer parameters, including initial elastic modulus, initial tangent modulus, bulking factor, coal and rock bulk density, and compressive strength; S2. Calculate the heights of the caving zone, fissure zone, bending subsidence zone, and floor failure according to the coal seam mining height, and divide the plastic expansion zone, elastic expansion zone, and virgin rock stress zone; S3. Calculate the total unloading expansion amount of the overlying rock in the plastic expansion zone during single mining according to the stress-strain relationship of the caving rock mass; and calculate the total unloading expansion amount of the overlying rock in the elastic expansion zone during single mining according to Hooke's law; obtain the total overlying rock expansion amount during single mining; S4. Calculate and obtain the amount of strata separation during single mining according to steps S2 and S3; S5. Calculate the influence of multiple mining actions and equivalent it to the equivalent thickness of the single mining coal seam based on the occurrence characteristics of coal seam groups, coal seam mining height, and the floor failure situation during single mining; among them, based on the occurrence characteristics of coal seam groups include: close-distance, medium-distance, and long-distance coal seam groups; The close-distance coal seam group is defined as a coal seam group with a very close layer spacing of multiple minable coal seams, having significant mutual influence during mining, and the caving zones of which can be connected after mining; The medium-distance coal seam group is defined as a coal seam group with a moderate layer spacing of multiple minable coal seams, having alternating influence during mining, and the caving zone and fissure zone of which appear alternately after mining; The long-distance coal seam group is defined as a coal seam group with a relatively far layer spacing between multiple minable coal seams, having no significant influence during mining, and the "three zones" of which appear alternately after mining; the calculation according to the coal seam mining height includes calculating the mining spacing of the upper protective layer and the lower protective layer, where: The calculation formula for the mining of the upper protective layer is: Equivalent relative layer spacing of the upper protective layer The calculation formula for the mining of the lower protective layer is: Equivalent relative layer spacing of the lower protective layer wherein, R is the equivalent relative layer spacing between the protective layer and the protected layer; R0 is the relative layer spacing between the protective layer and the protected layer; S is the vertical layer spacing between the protective layer and the protected layer; β α is the coal seam dip angle coefficient; K is the roof control coefficient; β1 is the influence coefficient of the mining height of the protective layer; β2 is the coefficient of the hard rock content between layers; β3 is the floor failure coefficient of the upper protective layer mining; M is the mining thickness of the protective layer; Based on the multiple mining equivalent quantification of overlying rock unloading expansion, calculate the equivalent thickness of the single mining coal seam and equivalent it to the coal seam thickness of the first mined layer, including: Calculate the equivalent thickness of the second mining equivalent to the coal seam thickness of the first mined layer as ΔM: In the formula, are the equivalent coal seam thicknesses of the separation amounts for single mining and secondary mining respectively; δ1 and δ2 are the separation amounts for single mining and secondary mining respectively; S g is the area between specific coal seam distances; a is the length of the separation space model; b is the width of the separation space model; Calculate the equivalent thickness of the third mining equivalent to the coal seam thickness of the first mined layer as ΔM': wherein are respectively equivalent coal seam thicknesses of separation amounts in the third mining and the second mining; δ3 and δ2 are respectively separation amounts in the third mining and the second mining.

2. The equivalent quantification method for multiple mining of coal seam groups according to claim 1, wherein In step S2, the calculation of the heights of the caving zone, fissure zone, bending subsidence zone, and floor failure according to the coal seam mining height includes: Calculate the height of the caving zone: Where H m is the height of the caving zone; ∑M is the cumulative thickness of the mined coal seams; Calculate the height of the fissure zone: Where H li is the height of the caving zone; ∑M is the cumulative thickness of the mined coal seams; Calculate the height of the bending subsidence zone: H w = H-H m -H li ; Where, H w is the height of the caving zone; Calculate the height of the floor failure: h = 0.0085M + 0.1665α + 0.1079L - 4.3579; In the formula, h is the height of the floor failure; M is the mining depth, taking the average mining depth of the working face; α is the formation dip angle, taking the average formation dip angle; L is the inclined length of the working face.

3. A method for equivalent quantification of multiple mining in coal seam groups as described in claim 1, characterized in that In step S3, the steps for obtaining the total overlying rock expansion amount during single mining include: Set the stress-strain relationship of the caving rock mass: In the formula, σ1 is the axial stress; ε1 is the axial strain; ε m1 is the maximum possible axial strain, here referring to the strain of the dilated coal and rock relative to the original coal and rock; E0 is the initial tangent modulus, σ c is the set coefficient; it also includes: Calculate the overlying rock expansion amount within the range of a single direction: In the formula, f(y′) is the amount of overburden expansion within the range of y; l is the height of the plastic expansion zone; is the coefficient of coal and rock dilatancy at a distance of y1 from the mining seam in the plastic expansion zone; is the coefficient of coal and rock dilation unloading at a distance of y2 from the mining seam in the elastic expansion zone; is the amount of overburden expansion in the plastic expansion zone; is the amount of overburden expansion in the elastic expansion zone; Among them, the relationship between the bulking factor, unloading expansion coefficient, and coal and rock load is as follows: In the formula, σ1 is the vertical stress in the plastic expansion zone; K0 is the initial bulking factor; E0 is the initial tangent modulus; σ2 is the vertical stress in the elastic expansion zone; E is the elastic modulus; It also includes: Calculate the total overlying rock expansion amount f1 during single mining: f1 = H k + G j - G r ; Where H k is the total swelling amount of overlying strata in the plastic swelling zone; G j is the total swelling amount of overlying strata in the elastic swelling zone; G r is the total swelling amount of overlying strata in the elastic swelling zone of the floor.

4. A method for equivalent quantification of multiple mining in coal seam groups according to claim 1, characterized in that In step S4, the calculation and obtaining of the amount of strata separation during single mining according to steps S2 and S3 are specifically: δ1 = M1 - f1; In the formula, M1 is the coal seam mining thickness during single mining; f1 is the total overlying rock unloading expansion amount during single mining.

5. A method for equivalent quantification of multiple mining in coal seam groups according to claim 1, characterized in that In step S5, calculating the influence of multiple mining actions and equivalent to the equivalent thickness of a single mined coal seam includes: Calculating the equivalent thickness of the coal seam affected by mining using the amount of separation by the volume method, as shown in the following formula: In the formula, is the equivalent coal seam thickness of the separation amount; Ω is the separation volume of the upper protected coal seam. It is considered that the separation is a cuboid fitting model in three-dimensional space, and its calculation formula is where δ is the separation amount.

6. A method for equivalent quantification of multiple mining in a coal seam group according to claim 1, for the method of equivalent quantification calculation of multiple mining in a close-distance coal seam group, characterized in that: The equivalent thickness of the second mining to the first mined coal seam is ΔM: Where, H k is the total amount of overlying rock expansion in the plastic expansion zone for single mining; G j is the total amount of overlying rock expansion in the elastic expansion zone for single mining; G r is the total amount of overlying rock expansion in the elastic expansion zone of the floor for single mining; H k ′, H r are the total amounts of overlying rock expansion in the plastic expansion zone for secondary mining; G j ′ is the total amount of overlying rock expansion in the elastic expansion zone for secondary mining; G s is the total amount of overlying rock expansion of the floor for secondary mining; M2 is the thickness of the coal seam mined in the secondary mining The equivalent thickness of the third mining to the first mined coal seam is ΔM': Wherein, M3 is the mining thickness of the coal seam mined for the third time; H k ″, H r ′, H s is the total amount of overburden rock expansion in the plastic expansion zone mined for the third time; G j ″ is the total amount of overburden rock expansion in the elastic expansion zone mined for the third time; G w is the total amount of overburden rock expansion in the floor mined for the third time.

7. A method for equivalent quantification of multiple mining in a coal seam group according to claim 1, for the method of equivalent quantification calculation of multiple mining in a medium- and long-distance coal seam group, characterized in that: The equivalent thickness of the second mining to the first mined coal seam is ΔM: Wherein, M2 is the mining thickness of the coal seam mined for the second time; H k is the total amount of overburden expansion in the plastic expansion zone during single mining; G j is the total amount of overburden expansion in the elastic expansion zone during single mining; H k ′, H d is the total amount of overburden expansion in the plastic expansion zone during secondary mining; G j ′, G c is the total amount of overburden expansion in the elastic expansion zone during secondary mining; The equivalent thickness of the third mining to the first mined coal seam is ΔM': Wherein, M3 is the mining thickness of the coal seam mined for the third time; H k ″, H d ′, H b is the total amount of overburden expansion in the plastic expansion zone mined for the third time; G j ″, G c ′, G a is the total amount of overburden expansion in the elastic expansion zone mined for the third time.

8. A visualization system, characterized in that, Including: A visual system for equivalent quantification of multiple mining in a coal seam group. After inputting initial coal and rock layer parameters, mining thickness and other data, through the computer program of the memory and the processor, data processing is carried out according to instructions, and the intermediate results and final results of the processing are both displayed on the display interface, including: the amount of overburden expansion in the elastic expansion zone, the amount of overburden expansion in the plastic expansion zone, the total amount of overburden expansion, the amount of separation, the equivalent thickness; changing the input parameter data, the calculation results also change in real time; And, A memory for storing executable instructions; A processor for calculating data processing instructions; A screen for parameter input and calculation result display; The memory is used to store the computer program for implementing any one of the methods for equivalent quantification of multiple mining in a coal seam group according to claims 1 to 7; The processor is configured to implement a method for equivalent quantification of multiple mining in a coal seam group according to claims 1 to 7 when executing the computer program, The screen is configured to display a parameter input interface and a calculation result interface.

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