Ground pressure control method based on deep oversize underground mine frame type structure

Abstract

The invention provides a ground pressure control method based on a deep oversize underground mine frame type structure, and belongs to the field of underground mine mining. Horizontal isolation jambs are reserved on a middle section top plate of a deep mining area, and deep area jambs extending to a deep lowest service middle section are arranged; the whole deep mining area adopts a descending mining sequence, and the middle section between the two horizontal isolation pillars adopts an ascending mining sequence; the stopes between the adjacent deep area pillars form a frame unit, the stopes at the two ends are preferentially mined in the frame unit, and the stopes are filled in time to form a horizontal pressure relief stope, so that stoping stability of the stopes is facilitated; and meanwhile, before stoping of each stope, single-row downward fan-shaped pressure relief holes are drilled in surrounding rocks of upper and lower plates of the stope for advanced presplitting loosening blasting, and high-level stress load conduction of the deep stope is blocked. According to the method, high stress conduction of a deep mining area can be blocked, and the effects of relieving ground pressure appearing in the deep mining process and maintaining mine stability and stoping safety are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of underground mining, and in particular to a ground pressure control method based on a deep and extra-large underground mine frame structure. Background Art

[0002] The control of ground pressure in deep and large underground mines has always been a major problem in the mining industry, especially after the mines enter deep mining, the ground pressure problem they face becomes more prominent. Compared with the open-pit method and the caving method, the backfill mining method can use tailings and waste rock to fill the goaf, effectively control the surface settlement, and protect the surface structures from being damaged. A certain prior art patent discloses a method for backfill mining in the stage of extremely thick and large ore bodies under a strong ground pressure environment. The method first divides the plate area, and each plate area is divided into multiple mining areas. Mine pillars are left on both sides of the plate area. Each mining area is mined one by one from bottom to top, and the interval mining method is adopted. One mining area is backfilled, and three mining areas are mined and cut. After the backfilling is completed, the backfilling operation is carried out immediately to reduce the exposed area of ​​the side walls of the mining area to maintain the stability of the side walls and roof of the mining area.

[0003] However, with the mining and filling of large-scale ore resources, it is difficult to achieve complete top connection in the stope filling, which easily leads to the superposition of deformation of multiple middle-section filling bodies and causes large-scale regional settlement deformation on the surface, threatening the safety and stability of surface structures. In addition, after the deep-stage mining is completed, the large-scale filling body in the upper middle section will directly cover the deep mining stage, which is very likely to cause the collapse and instability of each middle-section filling body, affecting the stability of the entire mine. At the same time, under the deep high-stress environmental conditions, the stress field continues to change with large-scale mining. The mining area and reserved pillars may be destroyed under high concentrated stress, resulting in frequent ground pressure disasters such as rock bursts, stope spalling, roof and upper plate collapse, affecting the stability of the mine rock and production safety around the stope. Therefore, when mining in deep super-large underground mines, how to control the strong ground pressure to achieve safe and efficient ore mining is still a difficult problem to be solved in the field of underground mining. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present application provides a ground pressure control method based on a frame structure of a deep and extra-large underground mine, aiming to solve the technical problem that deep and extra-large underground mines are easily affected by ground pressure during mining, causing instability in the mining area, and thus affecting the mining work and the stability of the entire mine.

[0005] The embodiment of the present application provides a ground pressure control method based on a deep and large underground mine frame structure, comprising the following steps:

[0006] S1. Before the mine completes shallow mining and switches to deep mining, a horizontal isolation pillar is set on the middle roof of the deep mining area, and a deep area pillar extending to the lowest service middle section is set; the deep mining area as a whole adopts a descending mining sequence, and the middle section between two horizontal isolation pillars adopts an ascending mining sequence;

[0007] S2. In each middle section of the deep mining area, the stopes between two adjacent deep area pillars form a framework unit, and the stopes at both ends of the framework unit are mined first, and are filled in time after the mining is completed to form horizontal pressure relief stopes at both ends, and then other stopes to be mined in the framework unit are mined;

[0008] S3. Before mining each stope in the framework unit, a single row of downward fan-shaped pressure relief holes is drilled into the upper and lower surrounding rocks of the stope to carry out advance pre-splitting and loosening blasting. Then, mining is carried out on each stope in the framework unit according to the mining sequence of step S2, and mining of the middle section and even the entire deep mining area is gradually realized according to the mining sequence of step S1.

[0009] In the technical solution of the embodiment of the present application, deep regional pillars and horizontal isolation pillars are set in the deep mining area of ​​the mine to construct a regional frame structure, which is conducive to alleviating the superposition of filling deformation in a large-scale mining area and controlling the settlement deformation of the surface. At the same time, it can avoid the gravity load of multiple middle-stage fillings directly pressing on the filling body in the deep mining area, causing the filling body to collapse and become unstable, affecting the stability of the entire mine. In addition, within the frame unit, the end stopes are mined first and filled in time, and the weak stress conduction characteristics of the filling body can be used to block the high stress conduction in the horizontal direction of the deep mining area, which is conducive to the safety and stability of the recovery process of other stopes in the frame unit.

[0010] In addition, in this technical solution, the overall mining sequence of the deep mining area of ​​the mine is designed as downward mining, while the middle ore body between the horizontal isolation pillars is mined in an upward sequence, avoiding operations under the filling body and waste of pillar resources. At the same time, the stope inside the deep frame unit is in the mining stress release zone of the upper frame unit, and the stope in the adjacent horizontal isolation pillar continues to be mined in an upward sequence, and the upper middle stope is further released from stress, which is generally beneficial to the ground pressure control of the top and bottom plates of the deep mining stope.

[0011] In some embodiments, in step S1, the regional pillars reserved in the shallow mining area of ​​the mine are extended downward to the lowest service middle section of the deep area to form the deep regional pillars, and deep regional pillars extending to the lowest service middle section are re-set at intervals in the deep mining area below the filling area of ​​the shallow mining area of ​​the mine where no regional pillars are reserved, so as to complete the setting of deep regional pillars in the entire deep mining area. The spacing of the re-set deep regional pillars is 200 to 300 meters.

[0012] In this embodiment, regional pillars reserved in the shallow mining area of ​​the mine are extended downward to the lowest service middle section in the deep part to form deep regional pillars, which saves mining costs and improves mining efficiency. At the same time, for the filling area where no regional pillars are reserved in the shallow part, according to the change of ore body thickness and whether there are structures that need to be protected on the surface, deep regional pillars are also set at a certain distance in the deep mining area below it, and continue to extend to the depth after the deep mining area turns downward, and cooperate with horizontal isolation pillars of a certain thickness set on the middle section roof to construct a deep super-large underground mine framework-type ground pressure control structure, which plays a role in alleviating the ground pressure manifestation in the deep mining process and maintaining the stability of the mine.

[0013] In some embodiments, the deep mining area also includes an upper middle section through-vein tunnel arranged at the upper part of each middle section of the mining area, and a plurality of segmented rock drilling tunnels arranged in each mining area, and the upper middle section through-vein tunnel is arranged in parallel with the segmented rock drilling tunnel. In step S3, the drilling working surface of the downward fan-shaped pressure relief hole is the inner wall of the upper middle section through-vein tunnel or each segmented rock drilling tunnel. The downward fan-shaped pressure relief hole is 4 to 5 meters away from the mining area boundary, the hole diameter is Φ50 to 80 mm, the hole bottom distance is 2.5 to 3.5 meters, and the charging method is uncoupled charging.

[0014] In this embodiment, before mining in the mining area, a row of downward fan-shaped medium-deep holes are first arranged in the upper and lower plates of the mining area using the upper and middle sections of the vein-piercing tunnels or the segmented rock drilling tunnels, and advanced pressure relief blasting is carried out, which is beneficial to relieve the high stress transmitted from the upper and lower plates of the deep mining area, effectively block the transmission of high-level stress loads in the deep mining area, and further improve the stability of the surrounding rock of the upper and lower plates during the mining process of the mining area.

[0015] In some embodiments, in step S1, the vertical spacing of the horizontal isolation pillars is 2 to 3 mid-section heights, and the thickness is 20 to 30 m.

[0016] In some embodiments, the deep mining area is further provided with a middle transport tunnel connected to the upper middle vein tunnel and a segmented transport tunnel connected to the segmented rock drilling tunnel at the same vertical height. The upper middle vein tunnel and the segmented rock drilling tunnel are further provided with a chute in the area extending outside the vein, and the chute is perpendicular to the upper middle vein tunnel and the segmented rock drilling tunnel.

[0017] In some embodiments, the mining method of each stope is a staged drilling followed by empty-stop and fill mining method.

[0018] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is a schematic diagram of the overall structure of a ground pressure control method based on a framework structure of a deep and extra-large underground mine in an embodiment of the present application;

[0021] Figure 2 This is a front view of the frame unit in the embodiment of the present application;

[0022] Figure 3 for Figure 2 Schematic diagram of the structure in the middle BB direction;

[0023] Figure 4 for Figure 2 Schematic diagram of the structure in the CC direction;

[0024] Description of reference numerals:

[0025] 110-shallow area pillars; 120-deep area pillars; 130-horizontal isolation pillars; 140-frame unit; 141-horizontal pressure relief mining area; 142-downward fan-shaped pressure relief holes; 143-mining area to be mined; 150-upper and middle section vein tunnel; 160-segmented rock drilling tunnel; 170-middle section transport tunnel; 180-segmented transport tunnel; 190-chute; 200-surface; 300-ore body; 400-filling body; 500-surrounding rock. DETAILED DESCRIPTION

[0026] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0028] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0031] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0032] In the field of underground mining, the ground pressure control of deep and large underground mines has always been a major problem in the mining industry, especially after the mine enters deep mining, the ground pressure problem is more prominent. In the filling mining method, with the mining and filling of large-scale ore resources, it is difficult to achieve complete top contact in the stope filling, which is easy to cause the deformation of multiple middle-section filling bodies to superimpose and cause large-scale regional settlement deformation on the surface, threatening the safety and stability of surface structures. After the mine completes the deep-stage mining, the large-scale filling body in the upper middle section will directly cover the deep mining stage, which is very likely to cause the collapse and instability of the filling bodies in the middle sections, affecting the stability of the entire mine. At the same time, under the high-stress environmental conditions in the deep, the stress field continues to change with large-scale mining. The mining area and reserved pillars may be destroyed under high concentrated stress, resulting in frequent ground pressure disasters such as rock bursts, stope spalling, roof and upper plate collapse, affecting the stability of the mine rock and production safety around the stope.

[0033] In order to solve the technical problem that deep and extra-large underground mines are easily affected by ground pressure during mining, causing the mine to become unstable, thereby affecting the mining work and the stability of the entire mine, the present application provides a ground pressure control method based on a deep and extra-large underground mine frame structure, which controls the mining sequence of the mine to be a downward type, and at the same time, utilizes the support and partitioning effect of the horizontal isolation pillars to adjust the middle section mining sequence in the adjacent horizontal isolation pillars to an upward type, avoiding working under the filling body, and controlling the ground pressure manifestation of the top and bottom plates of the mine. By setting deep regional pillars and horizontal isolation pillars in the deep mining area of ​​the mine and constructing a regional frame structure, it is beneficial to alleviate the superposition of filling body deformation in a large-scale mining area and control the settlement deformation of the surface, and at the same time, it can avoid the gravity load of multiple middle-section fillings directly pressing on the filling body in the deep mining area, causing the filling body to collapse and become unstable, affecting the stability of the entire mine. Regional pillars are used to divide each middle section of the mining area into multiple frame units. The end mining area is given priority in the frame unit and filled in time. The end mining area is given priority in the unit, and loosening blasting is carried out by arranging downward fan-shaped advanced pressure relief holes in the upper and lower plates, which effectively blocks the transmission of high-level stress loads in the deep mining area, which is beneficial to the safety and stability of the mining process.

[0034] For the convenience of explanation, the following embodiments are described by taking a ground pressure control method based on a frame structure of a deep and extra-large underground mine according to an embodiment of the present application as an example.

[0035] Please refer to Figure 1 to Figure 4 The present application provides a ground pressure control method based on a deep and large underground mine frame structure, comprising the following steps:

[0036] S1. Before the mine completes shallow mining and switches to deep mining, a horizontal isolation pillar 130 is left on the middle roof of the deep mining area, and a deep area pillar 120 extending to the lowest service middle section of the deep mining area is set; the deep mining area as a whole adopts a descending mining sequence, and the middle section between the two horizontal isolation pillars 130 adopts an ascending mining sequence;

[0037] S2. In each middle section of the deep mining area, the stopes between two adjacent deep area pillars 120 form a frame unit 140. The stopes at both ends of the frame unit 140 are mined first, and are filled in time after the mining is completed to form horizontal pressure relief stopes 141 at both ends, and then other stopes 143 in the frame unit 140 are mined;

[0038] S3. Before mining each stope of the framework unit 140, a single row of downward fan-shaped pressure relief holes 142 are drilled into the upper and lower surrounding rocks 500 of the stope to carry out advance pre-splitting and loosening blasting. Then, mining is carried out on each stope in the framework unit 140 according to the mining sequence of step S2, and mining of the ore body 300 in the middle section and even the entire deep mining area is gradually realized according to the mining sequence of step S1.

[0039] In the technical solution of the embodiment of the present application, the overall mining sequence of the deep mining area of ​​the mine is designed as downward mining, and the middle section of the ore body between the horizontal isolation pillars 130 is mined in an upward sequence, avoiding operations under the filling body 400 and waste of pillar resources. The internal mining area of ​​the deep frame unit 140 is in the mining stress release area of ​​the upper frame unit 140, and the mining area in the adjacent horizontal isolation pillars 130, after the upward sequential mining, further stress release occurs in the upper middle section mining area, which is generally beneficial to the ground pressure control of the top and bottom plates of the deep mining mining area. At the same time, by setting deep regional pillars 120 and horizontal isolation pillars 130 in the deep mining area of ​​the mine, a regional frame structure is constructed, which is conducive to alleviating the deformation superposition of the filling body 400 in a large-scale mining area and controlling the settlement deformation of the surface 200. At the same time, it can avoid the gravity load of the filling body 400 in multiple middle sections directly pressing on the filling body 400 in the deep mining area, causing the filling body 400 to collapse and become unstable, affecting the stability of the entire mine. In addition, the end stopes in the frame unit 140 are mined first and filled in time, and the characteristics of the weak stress conduction of the filling body 400 can be used to block the high stress conduction in the horizontal direction of the deep mining area, which is conducive to the safety and stability of the recovery process of other stopes in the frame unit 140.

[0040] Further, in some embodiments, in step S1, the shallow regional pillars 110 left in the shallow mining area of ​​the mine are extended downward to the deep lowest service middle section to form deep regional pillars 120, and deep regional pillars 120 extending to the lowest service middle section are re-set at intervals in the deep mining area below the filling area where no regional pillars are left in the shallow mining area of ​​the mine, so as to complete the setting of deep regional pillars 120 in the entire deep mining area. The spacing of the re-set deep regional pillars 120 is 200 to 300 meters.

[0041] In the technical solution of the embodiment of the present application, the regional pillars reserved in the shallow mining area of ​​the mine are extended downward to the lowest service middle section in the deep part to form deep regional pillars 120, which saves mining costs and improves mining efficiency; at the same time, for the filling area where no regional pillars are reserved in the shallow part, according to the change in the thickness of the ore body and whether there are structures that need to be protected on the surface 200, deep regional pillars 120 are also set at a certain distance in the deep mining area below it, and continue to extend to the depth after the deep mining area turns downward, and cooperate with the horizontal isolation pillars 130 of a certain thickness set on the middle section roof to construct a deep super-large underground mine framework-type ground pressure control structure, which plays a role in alleviating the ground pressure manifestation during deep mining and maintaining the stability of the mine.

[0042] Further, in some embodiments, the deep mining area also includes an upper middle section vein tunnel 150 disposed on the upper part of each middle section of the stope, and a plurality of segmented rock drilling tunnels 160 disposed in each stope, and the upper middle section vein tunnel 150 is disposed in parallel with the segmented rock drilling tunnel 160. In step S3, the drilling working surface of the downward fan-shaped pressure relief hole 142 is the inner wall of the upper middle section vein tunnel 150 or each segmented rock drilling tunnel 160. The downward fan-shaped pressure relief hole 142 is 4 to 5 m away from the stope boundary, has a hole diameter of 50 to 80 mm, a hole bottom distance of 2.5 to 3.5 m, and a charge method of uncoupled charge.

[0043] In the technical solution of the embodiment of the present application, before mining in the mining area, a row of downward fan-shaped medium-deep holes are first arranged in the upper and lower plates of the mining area using the upper and middle sections of the vein-penetrating tunnels 150 or the segmented rock drilling tunnels 160, and advance pressure relief blasting is carried out, which is beneficial to relieve the high stress transmitted from the upper and lower plates of the deep mining area, effectively block the transmission of high-level stress loads in the deep mining area, and further improve the stability of the upper and lower plate surrounding rocks 500 during the mining process of the mining area.

[0044] Furthermore, in some embodiments, in step S1, the vertical spacing of the horizontal isolation pillars 130 is 2 to 3 mid-section heights, and the thickness is 20 to 30 m.

[0045] Furthermore, in some embodiments, the deep mining area is further provided with a middle transport tunnel 170 connected to the upper middle section vein tunnel 150, and a segmented transport tunnel 180 connected to the segmented rock drilling tunnel 160 at the same vertical height. A chute 190 is further provided in the area where the upper middle section vein tunnel 150 and the segmented rock drilling tunnel 160 extend outside the vein, and the chute 190 is perpendicular to the upper middle section vein tunnel 150 and the segmented rock drilling tunnel 160.

[0046] Furthermore, in some embodiments, the mining method of each stope is a staged drilling phase followed by empty-stop and fill mining.

[0047] Example 1

[0048] This embodiment provides a ground pressure control method based on a deep and large underground mine frame structure, comprising the following steps:

[0049] S1. Before the mine completes shallow mining and switches to deep mining, a horizontal isolation pillar 130 with a thickness of 25m is left on the middle roof of the deep mining area, and a deep area pillar 120 extending to the lowest service middle section of the deep mining area is set; the deep mining area as a whole adopts a downward mining sequence, and the middle section between the two horizontal isolation pillars 130 adopts an upward mining sequence;

[0050] S2. In each middle section of the deep mining area, the stopes between two adjacent deep area pillars 120 form a frame unit 140. The width of each stope is about 20m, and the height of the frame unit 140 is about 100m. The stopes at both ends of the frame unit 140 are mined first, and are filled in time after the mining is completed to form horizontal pressure relief stopes 141 at both ends, and then other stopes 143 in the frame unit 140 are mined;

[0051] S3. Before mining each stope of the framework unit 140, a single row of downward fan-shaped pressure relief holes 142 are drilled into the upper and lower surrounding rocks 500 of the stope to carry out advance pre-splitting and loosening blasting. Then, according to the mining sequence of step S2, each stope in the framework unit 140 is mined. Each stope is mined by the segmented rock drilling stage and then the empty site is mined with filling mining method. According to the mining sequence of step S1, the mining of the ore body 300 in the middle section and even the entire deep mining area is gradually realized.

[0052] Example 2

[0053] This embodiment provides an application example of a ground pressure control method based on a deep super-large underground mine framework structure in a certain mine. The mine is a super-large underground mine mainly engaged in iron ore mining. The main ore body is buried at a depth of 90m to -862m, with a dip angle of 68° to 75°, an average thickness of 50.30m, a length of the ore belt of 4.2km, and a maximum horizontal principal stress of more than 26MPa at a horizontal depth of -653m. The vertical height of the middle section of the mine is 100m. Starting from the wellhead, the first middle section is the -200m middle section, and the remaining middle sections are -300m, -400m, -525m, -625m, and the middle section that has not yet been developed in the deep part. When developing in depth, the mine adopts a ground pressure control method based on a deep super-large underground mine framework structure, which includes the following steps:

[0054] S1. First, the ore body between -400m and -425m levels is reserved as a horizontal isolation pillar. When the ore body below -625m level is mined, a horizontal isolation pillar is also required at the bottom of -625m level. The thickness is determined based on the results of theoretical and numerical calculations and is about 25m.

[0055] In order to protect the stability of surface structures, the mine has set up four regional pillars in the central mining section of the shallow -300m and -400m middle sections of the ore body and will not be mined temporarily. The span of the pillars is 20m, the height is the height of the middle section, the length is the thickness of the ore body, and the spacing is 100-220m. After entering the deep -625m and -525m middle sections for mining, the regional pillars temporarily left in the shallow middle section continue to extend to the depth to form deep regional pillars. At the same time, a deep regional pillar is set up every 260-300m at the north and south ends of the ore body. The deep regional pillars extend to the lowest service middle section in the deep section. The mining sequence adopted in the middle section is the upward mining sequence, that is, the deep middle section first mines the -625m middle section, and then the -525m middle section.

[0056] S2. In the middle section, the stopes between two adjacent deep area pillars form a framework unit. The stopes in the framework unit are divided vertically along the ore body. The stope height is 75-100m, divided into 4 sections, with a stope span of 20m and a stope length of 70m. Each stope is mined by the open-pit mining method followed by filling mining in the stage of segmented rock drilling. The order of mining in the middle section is to give priority to the stopes on both sides of the framework unit, and fill them in time after the mining is completed, forming horizontal pressure relief stopes at both ends, and then continue to mine other stopes to be mined in the framework unit.

[0057] S3. Before mining each stope in the framework unit, a single row of downward fan-shaped pressure relief holes is drilled into the surrounding rock of the upper and lower plates of the stope to carry out advance pre-splitting and loosening blasting. Then, mining is carried out on each stope in the framework unit according to the mining sequence of step S2, and mining of the middle section and even the entire deep mining area is gradually realized according to the mining sequence of step S1.

[0058] The mine is currently mainly conducting long-term settlement and displacement monitoring of the main and auxiliary shafts on the surface. Monitoring data over the years show that the maximum settlement displacement of the main and auxiliary shafts is 2.4mm, the overall settlement displacement is small, and the degree of deformation and damage caused by mining disturbance is small.

[0059] In summary, the present invention provides a ground pressure control method based on a framework structure of a deep, extra-large underground mine. By controlling the mining sequence of the mine to be a downward type, and utilizing the support and partitioning effect of the horizontal isolation pillars, the middle section mining sequence in the adjacent horizontal isolation pillars is adjusted to an upward type, so as to avoid working under the filling body and control the ground pressure manifestation of the top and bottom plates of the mining area. At the same time, by setting deep regional pillars and horizontal isolation pillars in the deep mining area of ​​the mine and constructing a regional framework structure, it is beneficial to alleviate the superposition of filling body deformation in a large-scale mining area and control the settlement deformation of the ground surface, and can avoid the gravity load of multiple middle sections of filling directly pressing on the filling body in the deep mining area, causing the filling body to collapse and become unstable, affecting the stability of the entire mine. In addition, the present invention uses regional pillars to divide each middle stope into multiple frame units, and the end stopes are mined first and filled in time within the frame units, and the end stopes are mined first within the units, and downward fan-shaped advanced pressure relief holes are arranged in the upper and lower plates for loosening blasting, which effectively blocks the transmission of high-level stress loads in deep stopes, which is beneficial to the safety and stability of the stope recovery process. This ground pressure control method based on the frame structure of deep super-large underground mines avoids the frequent occurrence of ground pressure disasters such as rock bursts, stope slabs, roof and upper plate collapse during deep mining, which affects the stability of the surrounding ore rocks and production safety of the stope.

[0060] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A ground pressure control method based on a framework structure of a deep and extra-large underground mine, characterized in that: The following steps are involved: S1. Before the mine completes shallow mining and switches to deep mining, a horizontal isolation pillar is set on the middle roof of the deep mining area, and a deep area pillar extending to the lowest service middle section is set; the deep mining area as a whole adopts a descending mining sequence, and the middle section between two horizontal isolation pillars adopts an ascending mining sequence; S2. In each middle section of the deep mining area, the stopes between two adjacent deep area pillars form a framework unit, and the stopes at both ends of the framework unit are mined first, and are filled in time after the mining is completed to form horizontal pressure relief stopes at both ends, and then other stopes to be mined in the framework unit are mined; S3. Before mining each stope in the framework unit, a single row of downward fan-shaped pressure relief holes is drilled into the upper and lower surrounding rocks of the stope to carry out advance pre-splitting and loosening blasting. Then, mining is carried out on each stope in the framework unit according to the mining sequence of step S2, and mining of the middle section and even the entire deep mining area is gradually realized according to the mining sequence of step S1.

2. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 1 is characterized in that: In step S1, the regional pillars reserved in the shallow mining area of ​​the mine are extended downward to the deep lowest service middle section to form the deep regional pillars, and in the deep mining area below the filling area where no regional pillars are reserved in the shallow mining area of ​​the mine, deep regional pillars extending to the lowest service middle section are re-set at intervals to complete the setting of deep regional pillars in the entire deep mining area.

3. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 1 is characterized in that: The deep mining area also includes an upper middle section vein-penetrating tunnel arranged above each middle section of the mining area and a plurality of segmented rock drilling tunnels arranged in each mining area. The upper middle section vein-penetrating tunnel is arranged in parallel with the segmented rock drilling tunnel.

4. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 3 is characterized in that: In step S3, the drilling working surface of the downward fan-shaped pressure relief hole is the inner wall of the upper middle section of the vein-penetrating tunnel or each segmented rock drilling tunnel.

5. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 1 is characterized in that: In step S1, the vertical spacing of the horizontal isolation pillars is 2 to 3 mid-section heights, and the thickness is 20 to 30 m.

6. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 2 is characterized in that: The spacing between the re-spaced deep area pillars is 200 to 300 meters.

7. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 1 is characterized in that: In step S3, the downward fan-shaped pressure relief hole is 4 to 5 m away from the stope boundary, has a hole diameter of 50 to 80 mm, a hole bottom distance of 2.5 to 3.5 m, and a charging method of uncoupled charging.

8. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 3 is characterized in that: The deep mining area is also provided with a middle transport tunnel connected to the upper middle section vein tunnel, and a segmented transport tunnel connected to the segmented rock drilling tunnels at the same vertical height.

9. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 8 is characterized in that: The upper middle section vein-penetrating tunnel and the segmented rock drilling tunnel extend to the area outside the vein and are also provided with a chute, and the chute is perpendicular to the upper middle section vein-penetrating tunnel and the segmented rock drilling tunnel.

10. The ground pressure control method based on the framework structure of a deep and extra-large underground mine according to claim 1, characterized in that: The mining method of each stope is a segmented rock drilling stage followed by empty-site filling mining.

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