Overlying strata low-position pressure relief and high-position filling dynamic disaster coupling control design method

Abstract

The invention relates to the technical field of deep dynamic disaster control, and discloses an overlying strata low-position pressure relief and high-position filling dynamic disaster coupling control design method which comprises the following steps: dividing strata units of a research area; and a low-position pressure relief model is established, and crustal stress balance calculation is carried out. And deep hole blasting schemes with different blasting parameters are designed, and circulating excavation and balance calculation are conducted on the coal seam till coal seam excavation is completed. Monitoring points are arranged on the overlying strata of the low-position pressure relief model, and a dynamic change curve of rock mass stress and displacement is obtained. And meanwhile, position coordinates of upper and lower rock stratum boundaries of the separation space are screened, and a grouting material unit conforming to the separation space form is generated. Proportional segmentation is carried out according to a grouting area, and different grouting filling rates are set; and designing a grouting material unit, and creating a high-position filling model. And comparing numerical results of different low-position pressure relief models and high-position filling models, carrying out coupling design on the two numerical models, and designing an optimal dynamic disaster coupling control scheme.

Description

Technical Field

[0001] This invention relates to the field of deep dynamic disaster control technology, specifically to a design method for coupled control of dynamic disasters caused by low-level overburden depressurization and high-level backfilling. Background Technology

[0002] Deep dynamic hazards pose a significant safety threat to underground engineering and deep resource development, primarily stemming from the sudden release of energy accumulated under conditions of high ground stress and intense mining stress. Under complex, high-stress conditions at depth, the surrounding rock is easily disturbed by external dynamic pressure, potentially triggering dynamic hazards such as rockbursts and mine tremors.

[0003] Currently, deep coal mines commonly employ pressure relief and backfilling measures to control the risk of deep dynamic disasters. Regarding pressure relief, underground blasting can alter the surrounding rock structure and reduce stress concentration in the overlying strata. As for backfilling, grouting can be used to fill the overlying strata to improve their stress characteristics and enhance overall stability. However, due to the increasingly complex geomechanical environment of deep coal mines, a single measure is insufficient to effectively control the risk of deep dynamic disasters; a coupled control method from the lower to the upper layers of the rock strata is needed.

[0004] However, before on-site construction, the control methods need to be rigorously designed. Currently, pressure relief design schemes are generally based on numerical simulation, and the simulation technology for downhole blasting measures is relatively mature. However, the simulation technology for delamination grouting measures still has certain shortcomings. Current research mainly uses discrete element method software to approximate the filling effect of delamination grouting by applying displacement constraints and limiting the mining volume in the delamination interval, without setting solid units for filling the delamination space. Therefore, it is impossible to accurately determine the effect of delamination grouting measures on the prevention and control of deep dynamic disasters. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention proposes a new method for controlling deep dynamic disasters by using discrete element numerical software to simulate delamination grouting measures. This method can accurately simulate the filling of delamination overburden with grouting and can be used to study the effectiveness of delamination grouting measures in preventing and controlling deep dynamic disasters.

[0006] To achieve the above objectives, the present invention is designed using the following technical solution: This invention proposes a design method for coupled control of dynamic disasters caused by low-level overburden decompression and high-level backfilling, comprising the following steps: Create a numerical model of the study area and divide the study area into strata units; Assign corresponding physical and mechanical parameters to each rock stratum unit and rock stratum joint unit; A low-level pressure relief model is created by dividing the blast hole units; Set the error balance rate and perform ground stress balance calculations on the low-level decompression model.

[0007] In areas of surface subsidence, rock mass displacement monitoring points are set up, and in key layer areas, surrounding rock stress monitoring points are set up to obtain dynamic change curves of rock mass stress and displacement. Blasting hole units with different blasting parameters are designed to relieve pressure on the specified rock strata. At the same time, the coal seam is cyclically excavated and balanced until the coal seam excavation balance calculation is completed, and the overlying high-level rock strata of the low-level pressure relief model generate a separation space. The location coordinates of the upper and lower rock strata boundaries in the delamination space are selected to generate grouting material units that conform to the morphology of the delamination space.

[0008] By accurately obtaining the grouting area and dividing the grouting area proportionally, different grouting filling rates are set; The properties of grouting materials with different ratios were determined, grouting material units with different mechanical properties were set up, and high-level filling models with different grouting parameters were created. By comparing the numerical results of different low-level depressurization schemes and high-level filling schemes, the two numerical models are coupled and designed. Combined with the engineering economic benefit analysis, an economical and reasonable design scheme is selected.

[0009] As a further technical solution, indoor and numerical experiments revealed that the blast hole element adopts the Mohr-Coulomb slip joint constitutive model, while the grouting material element adopts the Double-Yield constitutive model. The Double-Yield constitutive model more closely reflects the mechanical properties of the grouting material. In field applications, numerical experiments using these two constitutive models can realistically simulate on-site working conditions.

[0010] As a further technical solution, the low-position pressure relief model reduces the integrity of the rock mass by removing blasting hole units, and effectively releases the stress of the overlying rock layer on the working surface after optimizing the blasting parameters.

[0011] As a further technical solution, the high-level filling model accurately identifies the specific boundary range of the delamination space, and after error adjustment, creates grouting material units that conform to the size of the delamination space.

[0012] As a further technical solution, the coupling design method is as follows: Based on the low-position depressurization model, the calculation coupling with the high-position filling model is achieved by defining a fusion interval, so as to obtain the coupled numerical model of the two.

[0013] As a further technical solution, the optimal design parameters of the blasting hole unit and the grouting material unit include the diameter, angle, depth, spacing, grouting filling rate of the blasting hole, and the mechanical parameters of the grouting material.

[0014] As a further technical solution, the characteristic evaluation value of each control scheme is determined based on the coupled numerical model to calculate the quantitative evaluation index.

[0015] As a further technical solution, the characteristic evaluation value includes rock mass settlement. Stress concentration area of ​​surrounding rock and the development of rock fractures .

[0016] As a further technical solution, the quantitative evaluation index is the percentage of the difference between the initial scheme feature evaluation value and the design scheme feature evaluation value to the initial scheme feature evaluation value.

[0017] As a further technical solution, the control effect of different design schemes on dynamic disasters is determined based on a coupled numerical model of low-level overburden depressurization and high-level backfilling. Select design schemes that meet the control requirements; based on this, compare the economic benefits of each design scheme. (Including economic benefit analysis of two control measures: low-level pressure relief and high-level filling), to determine the optimal scheme for the systematic design of control effect and economic benefit.

[0018] The beneficial effects of this invention are as follows: This invention couples a low-level depressurization scheme with a high-level filling scheme. By fusing two numerical models, the effectiveness of different coupled design schemes in preventing dynamic disasters is compared and analyzed. Simultaneously, combined with engineering economic benefit analysis, a coupled control design method for dynamic disasters involving low-level overburden depressurization and high-level filling is developed. This method effectively simulates the coupled control effect of deep coal mine blasting and delamination grouting on dynamic disasters, effectively controlling low-level rock strata pre-fracture depressurization and high-level delamination space grouting and filling. Through systematic optimization of the control effect and economic benefits of the design scheme, the economic benefits of the design scheme are guaranteed while effectively preventing dynamic disasters. Attached Figure Description

[0019] The accompanying drawings included in this invention are intended to aid in a further understanding of the claims. The illustrative embodiments shown and their descriptions are for illustrating the invention and are not intended to unduly limit the scope of the invention.

[0020] Figure 1 Technical roadmap for the design method of coupled control of dynamic disasters in low-level overburden depressurization and high-level backfilling; Figure 2 Design drawing for a downhole blasting scheme to relieve pressure on overburden at low positions; Figure 3 Design drawing of grouting scheme for high-level filling of overburden; Among them, 1. coal seam, 2. surrounding rock, 3. blasting diameter, 4. blasting angle, 5. blasting depth, 6. blasting spacing, 7. working face advance direction, 8. separation space, 9. ungrouted area, 10. grouted area. Detailed Implementation

[0021] The following description is merely illustrative and is intended to illustrate the technical solutions and advantages of the present invention in a more detailed manner. Unless otherwise specified, all technical and scientific terms used herein should be understood to have the meaning commonly understood by those skilled in the art related to the present invention.

[0022] It should be noted that the use of these terms is primarily for describing specific implementations and is not intended to limit the various embodiments exemplified by the present invention. Furthermore, unless the context otherwise indicates, the singular form should also be considered to include the plural form.

[0023] As described in the background section, to address existing engineering problems, this invention provides a coupled control design method for dynamic disasters caused by low-level overburden depressurization and high-level filling. This method can accurately simulate the grouting and filling of overburden delamination, and is used to study the effectiveness of delamination grouting measures in preventing deep dynamic disasters. Furthermore, this invention couples low-level depressurization measures with high-level filling measures. By fusing two numerical models, the effectiveness of different coupled design schemes in preventing dynamic disasters is compared and analyzed. Simultaneously, combined with engineering economic benefit analysis, a coupled control design method for dynamic disasters caused by low-level overburden depressurization and high-level filling is formed. This method effectively simulates the coupled control effect of blasting measures and delamination grouting measures in deep coal mines, effectively controlling low-level rock strata pre-fracture depressurization and high-level delamination space grouting and filling. Through systematic optimization of the control effect and economic benefits of the design scheme, the economic benefits of the design scheme are guaranteed while effectively preventing dynamic disasters.

[0024] Specifically, the proposed design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters includes the following steps: Based on on-site geological survey data, an area of ​​size was created. p × q The numerical calculation model is used to divide the rock strata of the study area into units; among them, p Indicates the length of the study area; q Indicates the altitude of the study area; Assigning each rock stratum unit ( , ... ) and interlayer joint units ( , ... The corresponding physical and mechanical parameters; where n is a natural number. This represents the nth rock stratum unit; This represents the nth joint unit; By dividing the blast hole units ( , ... The Mohr-Coulomb slip joint element was used to create a low-position deep-hole blasting stress relief model, and boundary constraints and geostress conditions were applied; where n is a natural number. This represents the nth blast hole unit; Set the error balance rate e The numerical model is used to perform geostress balance calculations. In areas of surface subsidence, rock mass displacement monitoring points are set up, and in key layer areas, surrounding rock stress monitoring points are set up to obtain dynamic change curves of rock mass stress and displacement. Design downhole blasting schemes with different parameters ( , ... The specified rock strata are depressurized, and the coal seam is cyclically excavated and balanced until the coal seam excavation balance calculation is completed. This results in a separation space in the overlying high-level rock strata of the low-level depressurization model; where n is a natural number. This represents the nth bombing scheme; Filter the position coordinates of the upper and lower rock strata boundaries in the delamination space ( , This generates grouting material units that conform to the delamination spatial morphology; By accurately identifying the grouting zone and dividing it proportionally, different grouting filling rates are set. , ... ), where n is a natural number, This represents the grouting filling rate of the nth grouting unit; The properties of grouting materials with different ratios were determined, grouting material units with different mechanical properties were set up, and delamination grouting schemes were developed based on different parameters. , ... A high-level filling model is created based on the Double-Yield constitutive model; where n is a natural number. This represents the nth grouting scheme; By comparing the numerical results of different low-level decompression models and high-level filling models, the two numerical models are coupled and the optimal design parameters of the blast hole unit and the grouting material unit are selected. Combined with the engineering economic benefit analysis, the best dynamic disaster coupling control scheme is designed.

[0025] Furthermore, in this embodiment, to ensure the accuracy of the numerical results, the mechanical parameters of the rock material need to be determined through indoor rock physics and mechanics experiments. The density of the rock strata is set as a rock stratum unit. bulk modulus shear modulus internal friction angle Cohesion and tensile strength Parameters such as these are used to assign corresponding mechanical properties to the blast hole joint elements, and the normal stiffness of the joint is set. Shear stiffness internal friction angle Cohesion and tensile strength Parameters such as these.

[0026] To ensure that the low-level stress relief model can accurately simulate the complex stresses in deep coal mines, the geostress error balance rate of the numerical model needs to be adjusted. e Precise control is achieved. Calculations are stopped when the local stress error balance rate is controlled within the allowable range, at which point the stress more closely approximates the complex stress conditions at depth.

[0027] Furthermore, in this embodiment, as Figure 2 As shown, taking the mining of coal seam 1 as an example, based on the mechanical properties of the surrounding rock 2, blasting hole units with different blasting parameters are divided to reduce the integrity of the rock mass. Along the working face advance direction 7, blasting holes with different blasting diameters 3, blasting angles 4, blasting depths 5, and blasting spacings 6 are set in the low-level pressure relief model to test different blasting schemes. , ... The pre-splitting and pressure relief effect on low-lying rock strata. Based on the economic benefit analysis of the blasting scheme, the selected blasting diameter was determined to be... w The blasting angle is a Explosion depth is h Explosion spacing is d The design scheme involves blasting and decompression of the low-lying rock strata.

[0028] Furthermore, in this embodiment, fixed-point monitoring of rock mass displacement is set up in the surface subsidence area, and fixed-point monitoring of surrounding rock stress is set up in the key layer area to obtain real-time change curves of rock mass displacement and stress within the area. A dynamic response curve of rock mass displacement is plotted with the calculation time step (step) as the abscissa and the rock mass displacement value as the ordinate. Similarly, a dynamic response curve of surrounding rock stress is plotted with the calculation time step (step) as the abscissa and the surrounding rock stress value as the ordinate. By analyzing the changes in rock mass displacement and stress in the monitoring area, the effectiveness of the design scheme in preventing and controlling deep dynamic disasters is quantitatively evaluated.

[0029] Furthermore, the coal seam is subjected to cyclic excavation and balance calculations until the coal seam excavation balance calculations are completed. The rock strata are divided into three major regions: the flexural subsidence zone (high-lying strata), the diameter zone (middle strata), and the caving zone (low-lying strata). A separation space is created by overlaying the high-lying strata onto the model. For example... Figure 3 As shown, by identifying the position coordinates of the rock strata boundaries above and below the delamination space 8 ( , After error adjustment, a grouting fusion zone is created. Voronoi polygons are used to divide the grouting material units into joints, and grouting material units that conform to the delamination space morphology are generated to establish a high-level filling model.

[0030] Furthermore, regarding Figure 3 Triaxial compression tests were conducted on grouting material samples from grouting area 10, and the constitutive relationship curves of the grouting material were determined. Through fitting analysis, the grouting material was assigned to a Double-Yield constitutive model. Grouting materials with different mix proportions and densities were designed. bulk modulus shear modulus internal friction angle Cohesion and tensile strength Grouting materials with equal parameters, comparing different grouting material schemes ( , ... The filling and pressure reduction effect of grouting was simulated by accurately obtaining the grouting interval range and proportionally dividing the grouting interval, controlling the spatial ratio of the ungrouted area 9 to the grouting area 10, and thus simulating different grouting filling rates. , ... The effect of grouting material on the prevention and control of deep dynamic disasters. The bulk modulus is Shear modulus is The internal friction angle is Cohesion is Tensile strength is Grouting filling rate At that time, the delamination grouting method can achieve an economical and reasonable filling and pressure reduction effect.

[0031] Furthermore, in this embodiment, the coupled control design method for dynamic disasters of low-level overburden depressurization and high-level filling is based on the low-level depressurization model, and achieves computational coupling with the high-level filling model by defining a fusion interval; wherein, the specific parameters include the diameter, angle, depth, spacing, grouting filling rate, and mechanical parameters of the grouting material of the blasting holes.

[0032] Furthermore, based on the coupled numerical model of low-level overburden depressurization and high-level infilling, characteristic evaluation values ​​for each control scheme are determined to calculate quantitative evaluation indicators; among these, the characteristic evaluation values ​​include rock mass settlement. Stress concentration area of ​​surrounding rock and the development of rock strata diameter The quantitative evaluation index is the percentage of the difference between the initial scheme characteristic evaluation value and the design scheme characteristic evaluation value relative to the initial scheme characteristic evaluation value. In this embodiment, the quantitative evaluation index includes the rock mass settlement change rate. , Surrounding rock stress variation rate and rock layer diameter variation rate .in In the formula, Let i be the rock mass settlement in design scheme i. This represents the rock mass settlement amount in the initial scheme; Let i be the stress concentration area of ​​the surrounding rock in design scheme i. This represents the stress concentration area of ​​the surrounding rock in the initial design. Let i be the diameter and development area of ​​the rock strata in design scheme i. The diameter of the rock strata in the initial scheme represents the development area.

[0033] Finally, the low-level depressurization scheme and the high-level backfilling scheme were integrated into a design. The numerical simulation results of the coupled model of low-level depressurization and high-level backfilling were analyzed to determine the control effect of different design schemes on dynamic disasters. In order to select those that meet the control effect A coupled design scheme is proposed. Based on this, the economic benefits of the above schemes are compared. (Including the economic benefit analysis of two control measures, low-level pressure relief and high-level filling), determine the optimal scheme for the systematic design of control effect and economic benefit, and form a dynamic disaster coupling control design method for overburden low-level pressure relief and high-level filling.

[0034] This embodiment proposes a novel method for controlling deep dynamic disasters by using discrete element numerical software to simulate delamination grouting measures. This method can accurately simulate the filling of delamination layers in overburden with grouting and can be used to study the effectiveness of delamination grouting measures in preventing and controlling deep dynamic disasters.

[0035] This embodiment couples the low-level depressurization scheme with the high-level filling scheme. By fusing two numerical models, the effectiveness of different coupled design schemes in preventing dynamic disasters is compared and analyzed. Finally, combined with engineering economic benefit analysis, a coupled control design method for dynamic disasters caused by low-level overburden depressurization and high-level filling is formed.

[0036] The design method proposed in this embodiment effectively simulates the coupled control effect of blasting and delamination grouting measures on dynamic disasters in deep coal mines, and effectively performs pre-fracture and pressure relief of low-lying rock strata and grouting and filling of high-lying delamination spaces. By systematically optimizing the control effect and economic benefits of the design scheme, the economic benefits of the design scheme are guaranteed while effectively preventing and controlling dynamic disasters.

[0037] The above description, in conjunction with the accompanying drawings, illustrates specific embodiments of the present invention, but does not limit the scope of protection of the present invention. Those skilled in the art should understand that any equivalent changes or modifications made based on the technical solutions of the present invention, or any proportional enlargement or reduction according to the design concept of the present invention, fall within the scope of protection of the present invention.

Claims

1. A design method for coupled control of dynamic disasters caused by low-level overburden depressurization and high-level backfilling, characterized in that, The method includes: Create a numerical model of the study area and divide the study area into strata units; Assign corresponding physical and mechanical parameters to each rock stratum unit and rock stratum joint unit; A low-level pressure relief model is created by dividing the blast hole units; Set the error balance rate and perform geostress balance calculations; Set up fixed-point monitoring of stress and displacement to obtain dynamic change curves of rock mass displacement in the surface subsidence area and surrounding rock stress in the key layer area. Design blasting hole units with different blasting parameters to depressurize the specified rock strata; at the same time, perform cyclic excavation and balance calculation of the coal seam until the coal seam excavation balance calculation is completed, and the overlying high rock strata of the low-level depressurization model generate a separation space. The location coordinates of the upper and lower rock strata boundaries in the delamination space are selected to generate grouting material units that conform to the shape of the delamination space; The grouting area is divided proportionally, and different grouting filling rates are set; grouting material units with different mechanical properties are designed, and high-level filling models with different grouting parameters are created. By comparing the numerical results of different low-level decompression models and high-level filling models, a coupled numerical model is obtained by coupling the two numerical models. The optimal design parameters of the blast hole unit and the grouting material unit are selected, and the best dynamic disaster coupled control scheme is designed.

2. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 1, characterized in that, The blast hole element adopts the Mohr-Coulomb slip joint element; the grouting material element adopts the Double-Yield constitutive model.

3. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 1, characterized in that, The low-position stress relief model reduces the integrity of the rock mass by removing blasting hole units, and effectively releases the stress of the overlying rock layer on the working surface after optimizing the blasting parameters.

4. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 1, characterized in that, The high-level filling model accurately identifies the specific boundary range of the delamination space, and after error adjustment, creates grouting material units that conform to the size of the delamination space.

5. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 1, characterized in that, The method of coupling design is as follows: Based on the low-level depressurization model, the computational coupling with the high-level filling model is achieved by defining a fusion interval, resulting in a coupled numerical model of the two.

6. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 5, characterized in that, The optimal design parameters of the blast hole unit and the grouting material unit include the diameter, angle, depth, spacing, grouting filling rate, and mechanical parameters of the blast hole and the grouting material.

7. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 5, characterized in that, The characteristic evaluation values ​​of each control scheme are determined based on the coupled numerical model, so as to calculate the quantitative evaluation index.

8. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 7, characterized in that, The characteristic evaluation values ​​include rock mass settlement. Stress concentration area of ​​surrounding rock and the development of rock fractures .

9. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 7, characterized in that, The quantitative evaluation index is the percentage of the difference between the initial scheme feature evaluation value and the design scheme feature evaluation value relative to the initial scheme feature evaluation value.

10. The design method for coupled control of low-level overburden depressurization and high-level backfilling dynamic disasters as described in claim 7, characterized in that, The control effects of different design schemes on dynamic disasters are determined based on the coupled numerical model, and the design scheme that meets the expected control effect is selected. On this basis, the engineering economic benefits of each design scheme are compared, and the optimal scheme of systematic design of control effect and economic benefits is determined.

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