A goaf filling method and system suitable for nondestructive mining

Abstract

The present application relates to the technical field of filling mining, in particular to a goaf filling method and system suitable for non-destructive mining. The method comprises predicting the weighting step distance of the dynamic instability area of the roof of the rock beam of the working face, determining the occurrence position and termination position of the initial weighting and periodic weighting, and determining the significant movement step distance of the rock beam and the relative stable step distance of the rock beam under the conditions of initial weighting and periodic weighting. According to the results of the predicted significant movement step distance of the rock beam and the relative stable step distance of the rock beam under the conditions of initial weighting and periodic weighting, the corresponding filling body is selected to perform filling operation in the area corresponding to the significant movement step distance of the rock beam and the relative stable step distance of the rock beam, until the filling operation of the working face is completed. The present method can actively control the significant movement area of the roof rock beam of the working face, and improve the stability of the stope overburden.

Description

Technical Field

[0001] This invention relates to the field of backfilling mining technology, specifically to a method and system for backfilling goaf in non-destructive mining. Background Technology

[0002] During mining operations, goaf areas are formed after mining. The formation of goaf areas causes a redistribution of stress in the surrounding rock mass, leading to rock deformation, damage, and movement, posing safety hazards to daily production. With increased mining intensity and face advance speed, the frequency of sudden dynamic instability phenomena at the mining face has significantly increased, especially large-area roof collapse disasters. Coal and rock dynamic instability disasters mainly include large-area roof collapse, rockburst, roof shearing, and roof fall / sparging. These disasters all exhibit strong dynamic instability characteristics and can severely lead to mine earthquakes in the mining area or even the entire mining area. Roof collapse disasters refer to the phenomenon where, as the coal face continues to advance and the exposed roof reaches a certain length, the basic roof fractures and breaks under its own weight and the load of the overlying strata, gradually collapsing as the face advances. When a roof collapse disaster occurs, the amount and speed of roof subsidence surge, and the roof fractures, leading to increased fissures, localized roof falls in the goaf, and severe coal wall spalling. If timely and effective protective measures are not taken before a pressure hazard occurs, the pressure hazard will cause incalculable harm and loss to personnel and equipment on the work surface.

[0003] To prevent collapses and large-scale subsidence of mined-out areas leading to pressure disasters, various methods are currently employed to treat them. Underground backfilling in coal mines is one such treatment measure. This method primarily utilizes waste rock or tailings as the main backfill aggregate. Through backfilling technology, the backfill material is gravity-flowed or pressurized into the underground mined-out area, supporting the surrounding rock and mitigating or preventing its deformation. Backfilling has long played a role in controlling surface movement and deformation, preventing surface subsidence from exceeding prescribed limits. However, this traditional backfilling mining technology merely allows the backfill to act as a passive buffer, preventing gradual spatial failure of the near-field rock mass under low-stress conditions. It lacks the ability to actively manage areas prone to dynamic instability of the working face roof. Summary of the Invention

[0004] This invention provides a method and system for filling goaf areas suitable for non-destructive mining, aiming to solve the problem that current goaf filling methods lack the ability to actively manage areas of dynamic instability disasters in the working face roof.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] A method for backfilling goaf in non-destructive mining, comprising:

[0007] Predict the pressure step distance in the dynamic instability zone of the rock beam top plate of the working face, determine the occurrence and termination positions of the initial pressure and periodic pressure, and determine the significant movement step distance and the relatively stable step distance of the rock beam under the initial pressure and periodic pressure conditions.

[0008] Based on the predicted significant movement distance and relatively stable distance of the rock beam under the initial and periodic pressure conditions, the corresponding filling body is selected and filling operations are carried out in the areas corresponding to the significant movement distance and relatively stable distance of the rock beam until the filling operation of the working face is completed.

[0009] As a further improvement of the present invention, the method of predicting the incoming pressure is as follows: based on the form of the initial incoming pressure on the overlying rock fracture of the top plate, combined with the relationship between the initial incoming pressure step distance and the periodic incoming pressure step distance under the same rock beam, the initial incoming pressure step distance and the periodic incoming pressure step distance of the top plate of the rock beam are calculated, and the occurrence and termination positions of the initial incoming pressure and the periodic incoming pressure are determined.

[0010] As a further improvement of the present invention, the pressure prediction method further includes: determining the significant motion step distance and the relatively stable step distance of the rock beam under the conditions of initial pressure and periodic pressure by using the relationship between the obtained initial pressure step distance, periodic pressure step distance and basic parameters of rock beam motion.

[0011] As a further improvement of the present invention, the method of selecting the filling body is as follows: when the advancing distance of the working face reaches the predicted relatively stable step distance of the rock beam, the goaf in the significant movement area during the rock beam movement process is filled with reinforced filling body. The distance of reinforced filling is the significant movement step distance of the rock beam corresponding to the initial pressure or periodic pressure.

[0012] When the advancing distance of the working face reaches the predicted significant movement step distance of the rock beam, conventional filling material is used to fill the goaf in the relatively stable area. The strength of the reinforced filling material is greater than that of the conventional filling material, and the roof contact rate of the reinforced filling material is greater than that of the conventional filling material.

[0013] As a further improvement of the present invention, the calculation formula for the initial pressure step distance of the top plate of the rock beam during the initial movement stage is as follows:

[0014] D1=a0+b0

[0015] In the formula, D1 is the initial pressure step distance, a0 is the initial significant movement step distance of the rock beam under pressure, and b0 is the initial relatively stable step distance of the rock beam under pressure.

[0016] As a further improvement of the present invention, the initial relative stability step distance of the rock beam under pressure refers to the limit span of cracking at the end of the rock beam, and the calculation formula for the limit span of cracking at the end of the rock beam is as follows:

[0017]

[0018] In the formula, L0 is the ultimate span of cracking at the end of the rock beam, m1 is the thickness of the basic top rock layer, [σ t ] represents the allowable tensile stress of the basic top rock layer, m2 represents the thickness of the rock layer above the basic top, and γ represents the average gravity density of the immediate top and the basic top.

[0019] As a further improvement of the present invention, the calculation method of the periodic pressing step distance of the rock beam top plate is as follows: based on the support conditions and stress of the rock beam, it is obtained by the ratio range of the periodic pressing step distance to the initial pressing step distance, wherein the ratio range of the periodic pressing step distance to the initial pressing step distance is 1 / 4 to 1 / 3.

[0020] As a further improvement of the present invention, the relationship between the periodic pressure step distance of the rock beam top plate, the significant movement step distance of the rock beam under periodic pressure, and the relatively stable step distance of the rock beam is as follows:

[0021] D2=a+b

[0022] In the formula, D2 is the periodic pressure step distance of the top plate of the rock beam, a is the significant movement step distance of the rock beam under periodic pressure, and b is the relatively stable step distance of the rock beam under periodic pressure.

[0023] As a further improvement of the present invention, the relatively stable step distance of the periodically pressing rock beam is calculated based on the roof subsidence of the coal face before periodic pressing, and the calculation formula is as follows:

[0024]

[0025] `

[0026] L = L A +b≈D2+b

[0027] In the formula, Δh' i L represents the amount of roof subsidence at the coal face before periodic pressure. K To control the top distance, h is the mining height, m. z For direct top thickness, K A L is the coefficient of fragmentation of the collapsed rock strata, L' is the ultimate span of the rock beam before the periodic pressure, and L A b is the minimum span of the rock beam at the end of the pressing operation where the support does not restrict the movement of the rock beam, and b is the relatively stable step distance of the rock beam during the periodic pressing operation.

[0028] The beneficial effects of this invention are as follows: The goaf filling method of this invention, applicable to non-destructive mining, predicts the pressure step distance of the dynamic instability area of ​​the working face rock beam roof. This yields the significant movement step distance and the relatively stable step distance of the rock beam under initial and periodic pressure conditions. Based on the prediction results, when the working face advances to the predicted relatively stable step distance of the rock beam, reinforced filling is carried out in the significantly moving area. When the working face advances to the predicted significant movement step distance of the rock beam, conventional filling materials are used for filling operations. Reinforced filling further increases the strength and roof contact rate of the filling material on the basis of the original filling material, thereby changing the stress state of the surrounding rock and enhancing its supporting capacity. Through the method of this invention, as reinforced filling proceeds, the overall strength of the filling material increases, the filling material's ability to absorb and transfer stress is enhanced, surrounding rock deformation is further controlled, the energy dissipation rate of the surrounding rock is slowed down, and the destructive development of the mine structure and surrounding rock is controlled, thus greatly improving the stability of the overburden in the stope.

[0029] This invention discloses a goaf filling system suitable for non-destructive mining, comprising a prediction model and a filling module. The prediction model is used to predict the pressure step distance of the dynamic instability area of ​​the working face rock beam roof, determine the occurrence and termination positions of the initial pressure and periodic pressure, and determine the significant movement step distance and the relatively stable step distance of the rock beam under the initial pressure and periodic pressure conditions. The filling module is used to select the corresponding filling body and perform filling operations in the area corresponding to the significant movement step distance and the relatively stable step distance of the rock beam under the predicted initial pressure and periodic pressure conditions, until the filling operation of the working face is completely completed. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the goaf reinforcement and backfilling method in an embodiment of the present invention;

[0032] Figure 2 This is a plan view of the goaf reinforcement and filling method in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the mechanical model of the top plate of the rock beam before the initial pressure in an embodiment of the present invention;

[0034] In the diagram: 1 is conventional backfill; 2 is reinforced backfill; 3 is the stop line; 4 is the working face track roadway; 5 is the main transport roadway; 6 is the public material roadway; 7 is the track uphill; 8 is the material transport uphill; 9 is the transport uphill. Detailed Implementation

[0035] To make the objectives and technical solutions of this invention clearer and easier to understand, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. The described embodiments are only some embodiments of the present invention, and not all embodiments.

[0037] The present invention provides a goaf filling method suitable for non-destructive mining. This method includes: predicting the pressure step distance of the dynamic instability zone of the working face rock beam roof, determining the occurrence and termination positions of the initial and periodic pressure, and determining the significant movement step distance and the relatively stable step distance of the rock beam under the initial and periodic pressure conditions; when the working face advances to the predicted relatively stable step distance of the rock beam, filling the goaf in the significant movement area during the rock beam movement process with reinforced filling material; when the working face advances to the predicted significant movement step distance of the rock beam, filling the goaf in the relatively stable area with conventional filling material; repeating this step until the filling operation of the working face is completed, wherein the strength of the reinforced filling material is greater than the strength of the conventional filling material, and the roof contact rate of the reinforced filling material is greater than that of the conventional filling material.

[0038] Example 1:

[0039] To enhance the filling of the mining area, alter the stress state of the surrounding rock mass, improve its strength, and strengthen its supporting capacity, thereby reducing roof subsidence and mitigating damage to the roof and surrounding rock, this embodiment proposes the following... Figure 1 The method shown is a goaf filling method suitable for non-destructive mining, the method comprising:

[0040] Predict the pressure step distance in the dynamic instability zone of the rock beam top plate of the working face, determine the occurrence and termination positions of the initial pressure and periodic pressure, and determine the significant movement step distance and the relatively stable step distance of the rock beam under the initial pressure and periodic pressure conditions.

[0041] In this step, the prediction process for the dynamic instability zone of the working face rock beam roof includes: based on the theory of mine pressure and strata control, and taking the caving method for roof management as a background, calculating the initial and periodic pressure steps of the rock beam roof based on the specific form of the initial pressure-overburden fracture in actual engineering, and combining the relationship between the initial pressure step and the periodic pressure step under the same rock beam, and determining the occurrence and termination positions of the initial and periodic pressure. The initial pressure step is related to factors such as the basic roof lithology, thickness, and geological structure, and is generally 20–50 m.

[0042] The pressure prediction step further includes: determining the significant movement step distance and the relatively stable step distance of the rock beam under the initial pressure and periodic pressure conditions, respectively, based on the relationship between the obtained initial pressure step distance, periodic pressure step distance, and basic parameters of rock beam movement. Coal mining and filling operations are then carried out while ensuring the normal operation of the coal mining machine, composite filling hydraulic support, and filling machinery.

[0043] Specifically, such as Figure 3 The diagram shows a mechanical model of the rock beam top plate before the initial pressure. The formula for calculating the initial pressure step distance D1 of the rock beam top plate is as follows:

[0044] D1=a0+b0

[0045] In the formula, D1 is the initial pressure step distance, a0 is the initial significant movement step distance of the rock beam under pressure, and b0 is the initial relatively stable step distance of the rock beam under pressure.

[0046] In this embodiment, the initial stable step distance of the rock beam under pressure is equal to the limit span for cracking at the end of the rock beam. The formula for calculating the limit span for cracking at the end of the rock beam is as follows:

[0047]

[0048] In the formula, L0 is the ultimate span of cracking at the end of the rock beam, m1 is the thickness of the basic top rock layer (in meters), [σ t [ ] represents the allowable tensile stress of the top rock layer, in Pa; m2 represents the thickness of the rock layer above the top rock layer, in meters; γ represents the average gravity density of the immediate top and the top rock layer, in N / m³. 3 Where m1, m2, and γ can all be obtained from the geological data of the specific mining area. The limit span of the crack at the end of the rock beam is calculated using this formula, and then the value of the relatively stable step distance of the rock beam under initial pressure is obtained. Since the initial pressure step distance is known, the significant movement step distance of the rock beam under initial pressure is then obtained.

[0049] The calculation method for the periodic pressure step distance of the rock beam top plate is as follows: based on the current support conditions and stress state of the rock beam, it is obtained through the range of the ratio between the periodic pressure step distance and the initial pressure step distance. Specifically, the ratio of the periodic pressure step distance to the initial pressure step distance ranges from 1 / 4 to 1 / 3. Using the obtained initial and periodic pressure step distances, combined with the relationship between the basic parameters of rock beam motion (relatively stable step distance, significant motion step distance, and pressure step distance), the significant motion and relatively stable step distance of the rock beam under the initial and periodic pressure conditions are determined.

[0050] The relationship between the periodic pressure step distance of the rock beam top plate, the significant movement step distance of the rock beam under periodic pressure, and the relatively stable step distance of the rock beam is as follows:

[0051] D2=a+b

[0052] In the formula, D2 is the periodic pressure step distance of the top plate of the rock beam, a is the significant movement step distance of the rock beam under periodic pressure, and b is the relatively stable step distance of the rock beam under periodic pressure.

[0053] The relatively stable step distance of the periodic rock-pressing beam is calculated based on the roof subsidence of the coal face before periodic pressing. The calculation formula is as follows:

[0054]

[0055] `

[0056] L = L A +b≈D2+b

[0057] In the formula, Δh' i L represents the amount of roof subsidence at the coal face before periodic pressure. K To control the top distance, h is the mining height, m. z For direct top thickness, K A L is the coefficient of fragmentation of the collapsed rock strata, L' is the ultimate span of the rock beam before the periodic pressure, and L A Let 'b' be the minimum span of the rock beam at the end of the pressure application without restricting its movement, and 'b' be the relatively stable step distance of the rock beam during periodic pressure application. In this embodiment, Δh' i L K h can be determined based on the actual site conditions, the specific geological conditions of different mines, or the on-site construction situation. m z K A The size can be obtained from the geological data of the mining area. By using the calculation formula for the subsidence of the roof of the coal face before periodic pressing, the size of the ultimate span L' of the rock beam before periodic pressing can be obtained. Since L'≈D2+b, and D2 is known, the size of the relative stable step distance b of the rock beam before periodic pressing can be obtained. Thus, the parameter value of the significant movement step distance a of the rock beam before periodic pressing can be calculated according to the relationship between a, b, and D2.

[0058] Based on the predicted significant movement distance and relatively stable distance of the rock beam under the initial and periodic pressure conditions, the corresponding filling body is selected and filling operations are carried out in the areas corresponding to the significant movement distance and relatively stable distance of the rock beam until the filling operation of the working face is completed.

[0059] Specifically, when the advancing distance of the working face reaches the predicted relatively stable step distance of the rock beam, the goaf in the significant movement area during the rock beam movement is filled with reinforced filling body 2.

[0060] When the advancing distance of the working face reaches the predicted significant movement step distance of the rock beam, conventional backfill material 1 is used to fill the goaf in the relatively stable area. This step is repeated until the filling operation of the working face is completed. The strength of the reinforced backfill material 2 is greater than that of the conventional backfill material, and the roof contact rate of the reinforced backfill material is also greater than that of the conventional backfill material. The distance of the reinforced backfill is the significant movement step distance of the rock beam corresponding to the initial or periodic pressure.

[0061] As the coal mining face advances, the roof collapses, exposing the rock strata for a certain span. After bending settlement reaches a certain value, weak interlayers or contact surfaces with low strength fail under axial shear stress, resulting in delamination. This creates conditions for the free settlement and movement of the lower rock strata to extend upwards. The layout of the modified working face is as follows: Figure 2 As shown, Figure 2 In this system, the roadways for track incline 7, material transport incline 8, and transportation incline 9 are vertically located on one side of the goaf. Track incline 7 connects to one end of the transversely located working face track roadway 4, which also connects to material transport incline 8. This common access point is located at stop line 3. Working face track roadway 4 also connects to the dynamic instability area (i.e., the area to be filled) of the working face rock beam roof. For the goaf within the relatively stable step distance of the pressure rock beam, conventional filling body 1 is used for filling, while for the goaf within the significantly moving area, reinforced filling body 2 is used, until the stop line 3 is reached. The other end of working face track roadway 4 connects to one end of the common material roadway 6 and the other end connects to the main transportation roadway 5. The main transportation roadway 5 and transportation incline 9 are connected via a coal chute. The main transport roadway 5 is used as a coal transport channel when the new transport roadway is not completed. The working face track roadway 4 is a material roadway that can transport backfill materials to the corresponding backfill area. The public material roadway 6 is a public roadway for transporting backfill materials, equipment, and raw coal. Raw coal enters the public material roadway 6 through the transport roadway and then enters the transport uphill roadway 9 through the main transport roadway 5 for transport. Backfill materials and equipment are transported upward through the material uphill roadway 8 and the track uphill roadway 7. Backfilling operations are stopped when the conventional backfill body 1 or the reinforced backfill body 2 has filled to the stop line 3.

[0062] In summary, the goaf filling method in this embodiment predicts the dynamic instability area of ​​the working face roof rock beam. When the working face advances to the predicted step distance, the goaf within the significant movement area of ​​the rock beam during its movement is reinforced and modified with filling. This further increases the strength and roof contact ratio of the filling material, altering the stress state of the surrounding rock and enhancing its support capacity. After the reinforced filling is completed, the filling method is changed, and ordinary filling operations continue. Using the reinforced filling belt working face layout, the significant movement area of ​​the working face roof rock beam is actively managed. As the reinforced filling progresses, the overall strength of the filling material increases, its ability to absorb and transfer stress is enhanced, surrounding rock deformation is further controlled, the energy dissipation rate of the surrounding rock is slowed, and the deterioration of the mine structure and surrounding rock is controlled, thereby significantly improving the stability of the overburden in the working face.

[0063] Example 2:

[0064] This embodiment presents a goaf backfilling system suitable for non-destructive mining, comprising a prediction model and a backfilling module. The prediction model is used to predict the pressure step distance of the dynamic instability zone of the working face rock beam roof, determine the occurrence and termination positions of the initial and periodic pressure, and determine the significant movement step distance and the relatively stable step distance of the rock beam under the initial and periodic pressure conditions. The backfilling module is used to select the corresponding backfill material and perform backfilling operations within the areas corresponding to the significant movement step distance and the relatively stable step distance of the rock beam under the predicted initial and periodic pressure conditions, until the backfilling operation of the working face is completed. The prediction model and backfilling module can effectively realize a goaf backfilling method suitable for non-destructive mining. The specific steps of this method have been described in detail in Embodiment 1 and will not be repeated here.

[0065] In this embodiment, the prediction model is a processor, which can be any processing machine with computing capabilities, such as a central processing unit (CPU) or an MCU.

Claims

1. A method for backfilling goaf in non-destructive mining, characterized in that, include: Predict the pressure step distance in the dynamic instability zone of the rock beam top plate of the working face, determine the occurrence and termination positions of the initial pressure and periodic pressure, and determine the significant movement step distance and the relatively stable step distance of the rock beam under the initial pressure and periodic pressure conditions. Based on the predicted results of the significant movement step distance and the relatively stable step distance of the rock beam under the initial and periodic pressure conditions, the corresponding filling body is selected and the filling operation is carried out in the area corresponding to the significant movement step distance and the relatively stable step distance of the rock beam until the filling operation of the working face is completed. The method for predicting the pressure step distance also includes: determining the significant movement step distance and the relatively stable step distance of the rock beam under the conditions of initial pressure and periodic pressure by using the relationship between the obtained initial pressure step distance, periodic pressure step distance and basic parameters of rock beam movement; The method for selecting the filling body is as follows: when the advancing distance of the working face reaches the predicted relatively stable step distance of the rock beam, the goaf in the significant movement area during the rock beam movement process is filled with reinforced filling body. The distance of reinforced filling is the significant movement step distance of the rock beam corresponding to the initial pressure or periodic pressure. When the advancing distance of the working face reaches the predicted significant movement step distance of the rock beam, conventional filling material is used to fill the goaf in the relatively stable area. The strength of the reinforced filling material is greater than that of the conventional filling material, and the roof contact rate of the reinforced filling material is greater than that of the conventional filling material.

2. The goaf filling method for non-destructive mining according to claim 1, characterized in that, The method for predicting the initial pressure step distance is as follows: based on the form of the initial pressure on the overlying rock fracture of the top plate, combined with the relationship between the initial pressure step distance and the periodic pressure step distance under the same rock beam, the initial pressure step distance and the periodic pressure step distance of the top plate of the rock beam are calculated, and the occurrence and termination positions of the initial pressure and the periodic pressure are determined.

3. The goaf filling method applicable to non-destructive mining according to claim 2, characterized in that, The formula for calculating the initial pressure step distance of the top plate of the rock beam is: In the formula, For the first time pressing the step distance, The initial significant movement step of the rock beam under pressure. This is the initial step distance for the relatively stable pressure beam.

4. The goaf filling method applicable to non-destructive mining according to claim 2, characterized in that, The initial stable step distance of the rock beam under pressure is equal to the limit span for cracking at the end of the rock beam. The formula for calculating the limit span for cracking at the end of the rock beam is as follows: In the formula, This represents the maximum span at which the rock beam ends can crack. This represents the thickness of the basic top rock layer. The allowable tensile stress of the basic top rock layer, The thickness of the basic top layer of rock. This represents the average gravity density of the immediate top and the fundamental top.

5. The goaf filling method for non-destructive mining according to claim 2, characterized in that, The calculation method for the periodic pressing step distance of the rock beam top plate is as follows: based on the current support conditions and stress of the rock beam, it is obtained through the ratio range of the periodic pressing step distance to the initial pressing step distance. The ratio range of the periodic pressing step distance to the initial pressing step distance is 1 / 4 to 1 / 3.

6. The goaf filling method for non-destructive mining according to claim 2, characterized in that, The relationship between the periodic pressure step distance of the rock beam top plate, the significant movement step distance of the rock beam under periodic pressure, and the relatively stable step distance of the rock beam is as follows: In the formula, The step distance is determined by the period of the rock beam top plate. The significant movement step of the rock beam under periodic pressure is... The relative stability step distance of the rock beam under periodic pressure.

7. The goaf filling method for non-destructive mining according to claim 6, characterized in that, The relatively stable step distance of the periodic rock-pressing beam is calculated based on the roof subsidence of the coal face before periodic pressing. The calculation formula is as follows: In the formula, The periodic amount of roof subsidence in the coal mining face before pressure is measured. To control the top distance, For mining height, For direct top thickness, The coefficient of fragmentation of the collapsed rock strata. The ultimate span of the pre-existing rock beam is determined by the periodic pressure. The minimum span of the rock beam at the end of the compression is determined by not restricting the movement of the rock beam by the support frame. The relative stability step distance of the rock beam is determined by the periodic pressure.

8. A goaf filling system suitable for non-destructive mining, characterized in that, The method for backfilling goaf in non-destructive mining as described in any one of claims 1 to 7 includes a prediction model and a backfilling module. The prediction model is used to predict the pressure step distance of the dynamic instability area of ​​the rock beam roof in the working face, determine the occurrence and termination positions of the initial pressure and periodic pressure, and determine the significant movement step distance and the relatively stable step distance of the rock beam under the initial pressure and periodic pressure conditions. The backfilling module is used to select the corresponding backfill body and perform backfilling operations in the area corresponding to the significant movement step distance and the relatively stable step distance of the rock beam under the predicted results of the initial pressure and periodic pressure conditions, until the backfilling operation of the working face is completed.

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