Method for determining sizes of panel and pillar in thick and large ore body filling mining method

Abstract

The invention belongs to the technical field of mining, and particularly relates to a method for determining the sizes of panels and jambs in a thick and large ore body filling mining method, which comprises the following steps of: determining the room limit length of a single filling room of a mine based on a Morse stability diagram method; establishing a mechanical model of a single mine room top column, and substituting the limit length of the mine room into the mechanical model of the single mine room top column to solve the thickness of the top column; establishing a limit equilibrium condition to obtain a maximum deflection model of the panel top pillar; comparing the settlement amount with a deflection range allowed by a constructional engineering manual, performing valuing, determining a panel limit length, and determining the panel length by taking the maximum integer number of chambers in the limit panel length range as a principle; taking the ratio of the strength of the panel jamb to the load borne by the panel jamb as the safety coefficient of the jamb, selecting a reasonable safety coefficient by considering the influence of the actual lateral confinement condition of the jamb on the supporting capacity of the jamb, and determining the width of the panel jamb. The technical problem that the traditional panel and pillar size is lack of determination basis is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of underground filling mining, and in particular relates to a method for determining the sizes of a panel and a ore pillar in a thick and large ore body filling mining method. Background Art

[0002] With the advocacy and popularization of policies such as green mining and environmental protection, more and more underground mines are using backfilling for mining, especially mines with rivers, farmlands, buildings and other protection requirements on the surface. The space formed after backfilling mining is filled with backfill materials, but due to the quality of the backfilling roof, the strength of the backfilling body, and the shrinkage of the backfilling body, some backfilling mining mines, especially large-scale continuous mining mines, still have problems such as surface movement, collapse, and cracking of structures. Therefore, in the design of underground backfilling mining, the plate area is usually divided at a certain distance along the length or width of the mining area, and a certain width of the plate area pillar is reserved between the plate areas. The plate area division and the plate area pillar reservation are of great significance for controlling the fall of the overburden of thick and large ore bodies and the surface settlement. At present, the size of the plate area and the plate area pillar is usually determined by the engineering analogy method, which lacks the corresponding scientific basis. Summary of the invention

[0003] Technical issues: In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a method for determining the size of filling mining panels and pillars, which solves the problem that the traditional panels and pillars lack a basis for determining their size, leading to problems such as surface movement, subsidence, and cracking of structures.

[0004] Technical solution: The present invention proposes a method for determining the size of the panel and the pillar in a thick and large ore body backfill mining method, the steps of which are: S1. Determine the limit length L0 of a single filling chamber in a mine based on the Matthews stability diagram method; S2. The top pillar of a single mine room is regarded as a simply supported beam, and the gravity of the filling body in the upper stage is regarded as the load acting on the simply supported beam to meet the strength requirements of the simply supported beam. A mechanical model of the top pillar of a single mine room is established, and the limit length L0 of the mine room is brought into the mechanical model of the top pillar of a single mine room to obtain the thickness δ of the top pillar; S3. The top column of the entire panel area is regarded as the floor beam, and the gravity of the filling body in the upper stage panel area is regarded as the load acting on the floor beam. The top column of the panel area meets the stiffness requirements, and the limit equilibrium condition is established to obtain the maximum deflection model of the top column of the panel area; the settlement amount is compared with the deflection range allowed by the construction engineering manual, and the value is taken to determine the limit length of the panel area. Then, the panel length L is determined based on the principle of taking the maximum integer number of mine rooms within the limit panel length range; S4: Increase the strength of the panel pillars Loads on the panel pillars The ratio of is taken as the safety factor F of the pillar k , consider the influence of the actual side limit conditions of the pillar on the supporting capacity of the pillar and select a reasonable safety factor F k , determine the width W of the panel pillar P .

[0005] Furthermore, the steps of the Matthews stability graph method in step 1 are: S11 determines the stability number N of the side walls and roof of the mine room based on the boundary conditions of the mine room and the mechanical properties of the ore rock: ; Where A is the rock stress coefficient; B is the joint attitude adjustment coefficient; C is the gravity adjustment coefficient; Q' value takes the approximate value Q, and Q is the rock mass quality index; S12 determines the corresponding hydraulic radius R based on the size of the mine room: ; Where S is the projected area of ​​the mine room, S=D×L0,m 2 ; W is the perimeter of the mine room projection surface, m; W=2×(D+L0), D is the width of the mine room, m; S13 Substitute the stability number N and the hydraulic radius R into the function expression of the stability-destruction line based on the Matthews stability diagram to determine the ultimate length L0 of the mine room; The functional expression of the stability-destruction line based on the Matthews stability diagram is: ; Where N is the stability number and R is the hydraulic radius, m.

[0006] Further, in step S11, The rock mass quality index Q is obtained according to RMR=9lnQ+44, where RMR is the rock mass quality score; Rock stress coefficient A and σ c / σ1 is linearly related, and its value range is: when σ c / σ1<2, A=0.1; when 2<σ c / σ1<10, A=0.1125(σ c / σ1)-0.125; when σ c / σ1>10, A=1; where σ c is the uniaxial compressive strength of the ore rock, MPa; σ1 is the induced stress of the excavation surface, MPa; The joint attitude adjustment coefficient B is calculated based on the relationship between the joint attitude and the inclination of the mining surface; The gravity adjustment coefficient C is solved by C=8-6cosα, where α is the surface inclination of the stope or gob, degrees.

[0007] Furthermore, the mechanical model of a single mine roof pillar in step S2 is: ; Where, δ is the thickness of the top pillar, m; K is the safety factor ranging from 1.5 to 3; γ is the density of the top pillar ore, kN / m³; L0 is the maximum length of the mine room, m; σ t is the tensile strength of rock, MPa.

[0008] Furthermore, the specific steps of step S3 are: S31 Based on the floor beam mechanical model of the top column of the panel area, the maximum deflection model of the top column of the panel area is derived as follows: ; Where, E is the elastic modulus of the top column of the panel area, Pa; L is the length of the panel area, m; I is the section moment of inertia of the top column of the panel area, m 4 ; q is the overlying load on the top column of the panel area, MPa / m.

[0009] S32 According to the Construction Engineering Design Manual, the allowable deflection [ω] of the floor beam is , taking the range of the allowable deflection as the maximum deflection, the range of the length L of the panel area is derived; S33 Deformation correction disc area length L based on the filling body settlement amount. After filling, the filling body will settle. The corresponding settlement amount Δ is determined according to the proportion of the filling body and the structural parameters of a single mine room. If ,Pick ,if , then take , bring the maximum deflection model into play to determine the limit length of the panel area, and determine the panel area length L with the maximum number of chambers within this value range.

[0010] Furthermore, the load on the panel pillar in step S4 The calculation formula is: ; In the formula, is the column load in the panel area, MPa; γ 均 is the average bulk density of the overlying rock, kN / m³; H is the distance from the top of the mine room to the ground surface, m; W p is the width of the pillar, m; h0 is the height of the pillar, m; n is the number of middle sections in the mine; δ is the thickness of the roof, m.

[0011] Further, the strength of the panel pillar in step S4 The calculation formula is: ; In the formula, is the triaxial compression strength of the pan area ore rock, MPa; ε is a constant, when W P / When h0>5, ε =1.4, when W P / When h0<5, ε =1.0.

[0012] Furthermore, in step S4, the safety factor F k Greater than 1.

[0013] Beneficial effects: The invention provides a method for determining the size of a panel and a ore pillar for filling a thick and large ore body. The method determines the limit length of a single filling mine room by using the Matthews stability diagram method, and ensures the stability of the roof and side walls of a single mine room during mining. The roof pillar of the mine room is regarded as a simply supported beam, and the limit thickness of the roof pillar is determined under the condition of meeting the strength condition. The entire panel ore pillar is regarded as a floor beam, and the panel length range is determined according to the allowable deflection specified in the architectural engineering design manual, so as to ensure that the roof and side walls of a single mine room are stable, the top pillar meets the strength requirement, and the entire panel meets the deformation requirement of the maximum deflection. The ore pillar support theory and strength calculation formula are used, and the lateral limit conditions of the ore body in filling bulk are considered, and the width of the panel ore pillar is calculated by using the triaxial ore compressive strength index of the ore rock, so as to determine the size of the panel ore room, the panel length, and the panel ore pillar, thereby filling the theoretical defects in the panel size design, and increasing the panel size as much as possible under the premise of ensuring the stability of the panel and ore room mining, so as to achieve safe and efficient filling and mining.

[0014] The method for determining the size of a thick ore body filling mining panel and pillars provided by the present invention solves the technical problem that there is a lack of basis for determining the size of traditional panel and pillars. It can not only ensure the production capacity of the panel, but also control the ore volume of the pillars and surface subsidence as much as possible, and is suitable for promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a front view of a thick ore body panel structure of the present invention; Figure 2 A top view of a thick ore body panel structure of the present invention; Figure 3 is the Matthews stability diagram, in which a is the upper limit of the stability-destruction line and b is the lower limit of the stability-destruction line; Figure 4 It is a reference diagram for the values ​​of various parameters in the Matthews stability diagram; Figure 5 It is the simply supported beam mechanical model of a single mine room; Figure 6 It is the mechanical model of floor beams in the panel area; Figure 7It is a cross-sectional view of the panel area; Figure numerals: 1. panel pillar, 2. panel, 3. mine room, 4. top pillar. DETAILED DESCRIPTION

[0016] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

[0017] like Figure 1 and Figure 2 As shown in the figure, in the design of underground backfill mining, the panel area is usually divided at a certain distance along the length or width of the stope, and a certain width of ore pillars, namely, panel area ore pillars 1, are left between the panels. The area between two adjacent panel area ore pillars 1 is a panel area 2. A panel area 2 is divided into multiple mine rooms 3. Figure 1 A top column 4 is arranged between adjacent mine rooms 3 in the up and down direction (as shown in FIG. 1 ).

[0018] The present invention proposes a method for determining the size of the panel and the pillar of a thick and large ore body filling mining method, the steps of which are: S1. Determine the limit length L0 of a single filling chamber in the mine based on the Matthews stability diagram method to ensure the stability of the roof and side walls during the mining process of a single chamber 3.

[0019] Specifically: S11, based on the boundary conditions of the mine room and the mechanical properties of the ore rock, determine the stability number N of the three side walls and the roof of the mine room: (1) Where A is the rock stress coefficient; B is the joint attitude adjustment coefficient; C is the gravity adjustment coefficient; Q' takes the approximate value Q, which is obtained by transforming the empirical formula between Q and RMR RMR=9lnQ+44, Q is the rock mass quality index, and RMR is the rock mass quality score; Figure 4 As shown in the figure, the rock stress coefficient A and σ c / σ1 is linearly related, and its value range is: when σ c / σ1<2, A=0.1; when 2<σ c / σ1<10, A=0.1125(σ c / σ1)-0.125; when σ c / σ1>10, A=1; σ c is the uniaxial compressive strength of the ore rock, MPa; the induced stress of the excavation surface, MPa; the joint occurrence adjustment coefficient B is calculated based on the relationship between the joint occurrence and the surface inclination angle α of the stope or empty area, such as Figure 4As shown; the gravity adjustment coefficient C can be solved using the formula C = 8-6cosα, where α is the surface inclination of the stope or empty area, °; Figure 2 As shown, the width D and inclination of the mine room are combined with the plan view, and the length, area and inclination of the empty area are obtained through the plan view and cross-section view of the corresponding stope.

[0020] S12. Determine the corresponding water conservancy radius R based on the size of the mine room 3: (2) Where S is the projected area of ​​the mine room, S=D×L0,m 2 ; W is the perimeter of the mine room projection surface, W=2×(D+L0), m; D is the width of the mine room, m; S13, Substitute the stability number N and the hydraulic radius R into the function expression of the stability-destruction line based on the Matthews stability diagram to determine the limit length L0 of the mine room; The functional expression of the stability-destruction line based on the Matthews stability diagram is: (3) Substitute the stability number N of the mine room 3 calculated in step S11 and the minimum hydraulic radius R required for the corresponding stability to destruction obtained in step S12 into formula (3), and then use formula (2) to obtain: Figure 3 As shown, the maximum length L0 of the mine room is determined, and the length of the mine room 3 is determined according to production requirements, so as to maximize the production capacity of the panel area 2.

[0021] Step S2: The top pillar 4 of a single mine room 3 is regarded as a simply supported beam, and the gravity of the filling body in the upper stage is regarded as the load q acting on the simply supported beam, which meets the strength requirements of the simply supported beam, such as Figure 5 As shown, taking the ultimate length L0 of the mine room as a parameter, a mechanical model of a single mine room roof pillar is established, and the thickness δ of the roof pillar is determined.

[0022] The mechanical model of a single mine roof pillar is: (4) Where, δ is the thickness of the top pillar, m; K is the safety factor ranging from 1.5 to 3; γ is the density of the top pillar ore, kN / m³; L0 is the maximum length of the mine room, m; σ t is the tensile strength of rock, MPa.

[0023] Substitute the parameters such as the chamber length determined in S1 into formula (4) to obtain the top pillar thickness δ corresponding to the chamber limit length L0, and then determine the top pillar thickness δ according to production requirements.

[0024] Step S3: The top column 4 of the entire panel area 2 is regarded as the floor beam, and the gravity of the filling body in the upper stage panel area 2 is regarded as the load q acting on the floor beam. The top column 4 of the panel area 2 meets the stiffness requirements, and the limit equilibrium condition is established to obtain the maximum deflection model of the top column 4 of the panel area 2; the settlement amount is compared with the deflection allowed by the construction engineering manual, and the value is determined to determine the limit length of the panel area, and then the panel length L is determined based on the principle of taking the maximum integer number of mine rooms 3 within the limit panel length range.

[0025] S31, based on the obtained mine room limit length L0 and top pillar thickness δ, as Figure 6 As shown, according to the floor beam mechanical model of the top column 4 of the panel area, the maximum deflection model of the top column 4 of the panel area is derived as follows: The maximum deflection model is: (5) Where E is the elastic modulus Pa of the top column of the panel area, L is the length of the panel area, m; I is the section inertia moment of the top column of the panel area, m 4 , , determine the maximum deflection based on the rock mechanics parameters and the size of the plate area 2 The relationship between q and the panel length L is MP / m.

[0026] S32. According to the Construction Engineering Design Manual, the allowable deflection [ω] of the floor beam is The maximum deflection is the range of the allowable deflection. , and derive the range of disk area length L.

[0027] S33, deformation correction based on filling body shrinkage. After filling, the filling body shrinks. The corresponding shrinkage Δ is determined based on the proportion of the filling body and the structural parameters of the single chamber 3. If ,Pick ,if , then take , substitute into formula (5) to determine the limit length of the panel area, and determine the panel area length L with the maximum number of chambers 3 within this value range.

[0028] Step S4: The strength of the panel pillars Loads on the panel pillars The ratio of is taken as the safety factor F of the pillar k , consider the influence of the actual side limit conditions of the pillar on the supporting capacity of the pillar and select a reasonable safety factor F k , determine the width W of the panel pillar P .

[0029] Specifically, based on the pillar support theory and strength calculation formula, a reasonable safety factor is selected to determine the width W of the pillar in the panel area, considering the influence of the actual side limit conditions of the panel pillar 1 on the support capacity of the panel pillar 1. P The steps are: S41. According to the pillar support theory, determine the load on the panel pillar: (6) In the formula, is the column load in the panel area, MPa; γ 均 is the average bulk density of the overlying rock, kN / m³; H is the distance from the top of the mine room to the ground surface, m; W p is the width of the pillar, m; h0 is the height of the pillar, m; n is the number of middle sections in the mine; δ is the thickness of the roof, m.

[0030] S42. Calculate the strength of the panel pillars according to the Bieniaw-ski formula: (7) In the formula, is the triaxial compression strength of the pan area ore rock, MPa; ε is a constant, when W P / When h0>5, ε =1.4, when W P / When h0<5, ε =1.0.

[0031] S43, using the panel pillar strength [σ] and the panel pillar load σ p The ratio of is taken as the safety factor F of the pillar k , determine the limit value of the width of the panel pillar.

[0032] F k The calculation formula is as follows: (8) To ensure the safety of the pillar, the safety factor is usually greater than 1. Considering that both sides of the plate pillar 1 are filled, that is, the pillar is under triaxial stress conditions, which is conducive to the support of the pillar, its safety factor is taken as a smaller value, and the width limit of the plate pillar 1 is determined, and a reasonable plate pillar width W is selected. p .

[0033] Example 1 This embodiment discloses a method for determining the size of a thick ore body filling mining panel. The ore body of an underground iron ore is a steeply inclined ore body with a dip angle of 65°, an ore body occurrence depth H=160m, a vertical extension of 360m, a medium-stable ore, a medium-developed joint, an occurrence similar to the ore-rock boundary, and an ore bulk density γ=32kN·m-3 , triaxial compressive strength σ c =135.2MPa, tensile strength σ t =15MPa, elastic modulus E=9.25Gpa, and the RMR score of the ore body is about 72.5. The stage drilling and subsequent filling mining are adopted, the stage height is 60m, the planned mine room width D=15m, and the filling body density is γ c =20kN·m -3 .

[0034] S1. Determine the limit length L0 of a single filling chamber in a mine based on the Matthews stability diagram method, and select a reasonable chamber length value based on production conditions.

[0035] S11 is based on the ore body quality score and calculates the ore body quality index according to the formula RMR=9lnQ+44 ; The maximum induced stress of the excavation surface σ1=22.41 MPa, σ c / σ1=3.5, therefore, rock stress coefficient A=0.1125(σ c / σ1)-0.125=0.269; after excavation of a single mine room, the angle between the joint and the roof and side wall is 65°, so B is taken as 0.85; through a large number of studies, scholars have found that in the exposed surface of the rock mass, the stability of the vertical side wall is 5 times higher than that of the roof. For the nearly horizontal exposed surface, the coefficient C=1 is selected, so the corresponding gravity adjustment coefficient C value of a single mine room is taken as 1; according to formula (1), the stability number N of the roof is calculated to be 5.437.

[0036] S12, mine room projection area S = 15L0, mine room projection surface perimeter W = 30 + 2L0, single mine room hydraulic radius R = 15L0 / (30 + 2L0); S13. Substitute the stability number N calculated in S11 into the functional expression (3) of the stability-destruction line in the Matthews stability diagram, and calculate that the ultimate hydraulic radius R of the mine room when it is stable is 6.137m. The corresponding ultimate length of the mine room is calculated to be 67.52m, which is taken as 60m.

[0037] S2. Consider the top pillar of a single mine room as a simply supported beam, and the gravity of the filling body in the upper stage as the load acting on the beam. The mechanical model of the top pillar of a single mine room is established to meet the strength requirements of the simply supported beam: (4) The bulk density of the top pillar ore rock is γ32KN / m 3 , top pillar ore rock σ t The pressure is 15 MPa, the safety factor range K of the top pillar is 1.5, and the length of the mine room L0 is 60 m. Substituting these parameters into formula (4) yields the ultimate thickness of the top pillar: ; Therefore, the thickness δ of the top column of the panel area can be taken as 6m.

[0038] S3. The top column of the entire panel area is regarded as the floor beam, and the gravity of the filling body in the upper stage is regarded as the load acting on the floor beam, so that the top column beam of the panel area meets the stiffness requirements, establishes the limit equilibrium condition, and determines the limit length of the panel area; and based on the filling body ratio and the determined settlement of the single mine room, the settlement comparison and the deflection allowed by the construction engineering manual are verified and compared, and the limit length of the panel area is comprehensively determined.

[0039] S31, according to the cross-sectional dimensions of the top column of the panel area, such as Figure 7 As shown, the moment of inertia of the disk section is calculated According to the floor beam mechanical model of the top column of the panel area, the relationship between the maximum deflection of the top column of the panel area and the length of the panel area is derived as follows: ; S32. The Construction Engineering Design Manual stipulates that the allowable deflection of the floor beam [ω] is To ensure safety, the allowable deflection is taken as the maximum deflection of the top column of the panel area, that is, ; It can be calculated that the maximum value of the panel length L is 128.7-162.1m; S33, backfill mining requires that the backfill slurry shrinkage index value should be less than 3%. According to the backfill height h0 in the mine room is 54m, the backfill shrinkage in the mine room after backfilling is Δ=54×3%=1.62m, which is much larger than the maximum deflection range of panel area 2 of 0.81m. Therefore, , L=162m is calculated. The maximum number of mine rooms within this range is 10, that is, the panel length L is 150m.

[0040] S4. Increase the strength of the panel pillars Loads on the panel pillars The ratio of , consider the influence of the actual side limit conditions of the pillar on the supporting capacity of the pillar and select a reasonable safety factor , determine the width W of the panel pillar P .

[0041] S41. According to the area bearing theory, determine the load model of the panel pillar: (6) Average bulk density of overburden and filling body γ 均 Take 22kN / m³, the distance H between the mine room top and the ground surface is 160m, the height of the pillar h0 is 54m, the number of middle sections of the mine n is 6; the thickness of the roof δ is 6m, and the above parameters are substituted into formula (6) to obtain: ; S42. According to the Bieniaw-ski formula, calculate the panel pillar strength model: (7) In the formula, σ c is the triaxial compressive strength of the panel pillar, which is 135.2MPa. The aspect ratio of the pillar is generally less than 1, that is, W P / A<1, so ε Take 1. Substituting the above parameters into formula (7), we get: ; S43, using pillar strength [σ] and pillar load σ p The ratio of is taken as the safety factor of the pillar, and its calculation formula is as follows: (9) To ensure the safety of the pillars, the safety factor is usually taken as a value greater than 1. Considering that both sides of the pillars in the panel area are backfill, which is conducive to the support of the pillars, a smaller safety factor can meet the strength requirements. Here, the safety factor is taken as 1.05. Substituting it into formula (9), we get: ; Calculate W P =19.67m, take 20m.

[0042] According to the above, the present disclosure provides a method for determining the size of a thick ore body filling mining panel and a ore pillar. By determining the limit length of a single filling ore room, the stability of the roof and side walls during the mining process of a single ore room is ensured; the entire panel ore pillar is regarded as a floor beam, the panel length range is determined according to the allowable deflection specified in the architectural engineering design manual, and the limit panel length is determined according to the scientific selection of the settlement amount of the filling body, the allowable deflection value is determined, the maximum number of ore rooms is determined within the limit length range of the panel, and the final panel length is calculated so that the panel meets the strength and deformation conditions, ensuring the safety of mining while increasing the panel size as much as possible, reducing the amount of ore pillars in the panel, and increasing the mining efficiency; considering the lateral limit conditions of the ore body in the filling bulk, the width of the panel ore pillar is calculated with the triaxial ore compressive strength index of the ore rock, so as to reduce the size of the panel ore pillar as much as possible. The present invention fills the theoretical defects in the panel size design, and increases the panel size as much as possible on the premise of ensuring the stability of the panel and ore room mining, so as to achieve safe and efficient filling and mining.

[0043] So far, the embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0044] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A method for determining the size of panels and pillars in a thick ore body backfill mining method, characterized in that: The steps are: S1. Determine the limit length L0 of a single filling chamber in a mine based on the Matthews stability diagram method; S2. The top pillar of a single mine room is regarded as a simply supported beam, and the gravity of the filling body in the upper stage is regarded as the load acting on the simply supported beam to meet the strength requirements of the simply supported beam. A mechanical model of the top pillar of a single mine room is established, and the limit length L0 of the mine room is brought into the mechanical model of the top pillar of a single mine room to obtain the thickness δ of the top pillar; S3. The top column of the entire panel area is regarded as the floor beam, and the gravity of the filling body in the upper stage panel area is regarded as the load acting on the floor beam. The top column of the panel area meets the stiffness requirements, and the limit equilibrium condition is established to obtain the maximum deflection model of the top column of the panel area; the settlement amount is compared with the deflection range allowed by the construction engineering manual, and the value is taken to determine the limit length of the panel area. Then, the panel length L is determined based on the principle of taking the maximum integer number of mine rooms within the limit panel length range; S4: Increase the strength of the panel pillars Loads on the panel pillars The ratio of is taken as the safety factor F of the pillar k , consider the influence of the actual side limit conditions of the pillar on the supporting capacity of the pillar and select a reasonable safety factor F k , determine the width W of the panel pillar P .

2. The method for determining the size of the panel and the pillar in the thick ore body backfill mining method according to claim 1, characterized in that: The steps of the Matthews Stability Diagram Method in step 1 are: S11 determines the stability number N of the side walls and roof of the mine room based on the boundary conditions of the mine room and the mechanical properties of the ore rock: ； Where A is the rock stress coefficient; B is the joint attitude adjustment coefficient; C is the gravity adjustment coefficient; Q' value takes the approximate value Q, and Q is the rock mass quality index; S12 determines the corresponding hydraulic radius R based on the size of the mine room: ； Where S is the projected area of ​​the mine room, S=D×L0,m 2 ; W is the perimeter of the mine room projection surface, m; W=2×(D+L0), D is the width of the mine room, m; S13 Substitute the stability number N and the hydraulic radius R into the function expression of the stability-destruction line based on the Matthews stability diagram to determine the ultimate length L0 of the mine room; The functional expression of the stability-destruction line based on the Matthews stability diagram is: ； Where N is the stability number and R is the hydraulic radius, m.

3. The method for determining the size of the panel and the pillar in the thick ore body backfill mining method according to claim 2, characterized in that: In step S11, The rock mass quality index Q is obtained according to RMR=9lnQ+44, where RMR is the rock mass quality score; Rock stress coefficient A and σ c / σ1 is linearly related, and its value range is: when σ c / σ1<2, A=0.1; when 2<σ c / σ1<10, A=0.1125(σ c / σ1)-0.125; when σ c / σ1>10, A=1; where σ c is the uniaxial compressive strength of the ore rock, MPa; σ1 is the induced stress of the excavation surface, MPa; The joint occurrence adjustment coefficient B is calculated based on the relationship between the joint occurrence and the surface inclination angle α of the stope or gob; The gravity adjustment coefficient C is solved by C=8-6cosα, where α is the surface inclination of the stope or gob, degrees.

4. The method for determining the size of the panel and the pillar in the thick ore body backfill mining method according to claim 1, characterized in that: The mechanical model of a single mine roof column in step S2 is: ； Where, δ is the thickness of the top pillar, m; K is the safety factor ranging from 1.5 to 3; γ is the density of the top pillar ore, kN / m³; L0 is the maximum length of the mine room, m; σ t is the tensile strength of rock, MPa.

5. The method for determining the size of the panel and the pillar in the thick ore body backfill mining method according to claim 1, characterized in that: The specific steps of step S3 are: S31 Based on the floor beam mechanical model of the top column of the panel area, the maximum deflection model of the top column of the panel area is derived as follows: ； Where, E is the elastic modulus of the top column of the panel area, Pa; L is the length of the panel area, m; I is the section moment of inertia of the top column of the panel area, m 4 ; q is the overlying load on the top column of the panel area, MPa / m; S32 According to the Construction Engineering Design Manual, the allowable deflection [ω] of the floor beam is , taking the range of the allowable deflection as the maximum deflection, the range of the length L of the panel area is derived; S33 Deformation correction disc area length L based on the filling body settlement amount. After filling, the filling body will settle. The corresponding settlement amount Δ is determined according to the proportion of the filling body and the structural parameters of a single mine room. If ,Pick ,if , then take , bring the maximum deflection model into play to determine the limit length of the panel area, and determine the panel area length L with the maximum number of chambers within this value range.

6. The method for determining the size of the panel and the pillar in the thick ore body backfill mining method according to claim 1, characterized in that: The load on the panel pillar in step S4 The calculation formula is: ； In the formula, is the column load in the panel area, MPa; γ 均 is the average bulk density of the overlying rock, kN / m³; H is the distance from the top of the mine room to the ground surface, m; W p is the width of the pillar, m; h0 is the height of the pillar, m; n is the number of middle sections in the mine; δ is the thickness of the roof, m.

7. The method for determining the size of the panel and the pillar in the thick ore body backfill mining method according to claim 1, characterized in that: Strength of the panel pillars in step S4 The calculation formula is: ； In the formula, is the triaxial compressive strength of the pan area ore rock, MPa; ε is a constant, when W P / When h0>5, ε =1.4, when W P / When h0<5, ε =1.

0.

8. The method for determining the size of the panel and the pillar in the thick ore body backfill mining method according to claim 1, characterized in that: Safety factor F in step S4 k Greater than 1.

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