A deep high-bearing ultra-large disc inter-pillar two-way combined pressure-relief stage mining method

Abstract

The application discloses a deep high-bearing ultra-large disc inter-pillar two-way combined pressure-relief stage mining method, and belongs to the technical field of mine engineering, which comprises the following steps: constructing two pressure-relief rock drilling galleries respectively at the position of the top of a stage disc inter-pillar close to the boundary of upper and lower discs; constructing a horizontal long drill hole penetrating the width of the inter-pillar from one of the pressure-relief rock drilling galleries to the other one, so as to form a top pressure-relief hole; constructing a cutting raise at a predetermined position of the starting end of the inter-pillar, taking the cutting raise as a free surface, and sequentially blasting to form a vertical cutting groove; excavating a cross roadway at the lower disc side of the inter-pillar, so that the cross roadway is connected with the upper two pressure-relief rock drilling galleries; constructing a downward large-diameter parallel deep hole in the cross roadway, and blasting to form a pressure-relief space; and through the horizontal two-way pressure relief combined with the top long drill hole, the horizontal stress of the inter-pillar is two-way controllable, so that a safe condition is provided for the mining operation, the continuous regulation and control of the ground pressure are realized, and the overall stability of the stope is ensured.

Description

Technical Field

[0001] This application belongs to the field of mining engineering technology, and in particular relates to a two-way combined decompression stage mining method for deep, high-bearing, ultra-large inter-panel pillars. Background Technology

[0002] As mineral resource extraction continues to deepen, the mining environment generally exhibits high ground stress characteristics. To maintain stope stability, control ground pressure, and prevent post-mining surface subsidence, conventional mining methods typically employ a structural design scheme that incorporates large-scale inter-panel pillars. As a key structure for dividing production operation units, inter-panel pillars provide the foundation for the orderly mining and production organization within the panel. Simultaneously, these pillars effectively ensure stope stability and ground pressure control during panel mining by transferring and bearing the enormous pressure from the overlying strata. To maintain their bearing capacity, inter-panel pillars are usually designed to be extremely large, resulting in a significant amount of mineral resources remaining within them. As mining within the panel gradually concludes, the extraction of inter-panel pillars becomes a necessary step to improve resource recovery rates.

[0003] During the mining process in the panel area, the pillar has accumulated high stress passively and a large amount of elastic strain energy inside, transforming it from a load-bearing structure into a high-energy dangerous body. Directly mining the pillar under this condition will disrupt the original stress balance, causing a drastic adjustment in the stress state of the surrounding rock, which can easily induce dynamic disasters such as rock bursts and rockbursts, seriously threatening the safety of personnel and equipment and hindering the smooth recovery of pillar resources. Summary of the Invention

[0004] In view of the technical problems existing in the background art, this application provides a deep, high-bearing, ultra-large inter-panel pillar bidirectional combined decompression stage mining method, including:

[0005] Arrange the preparation work;

[0006] Two pressure relief drilling tunnels were constructed at the top of the pillar between the two sections, near the boundary between the hanging wall and footwall.

[0007] A horizontal long borehole, spanning the width of the pillar, is drilled from one stress relief drilling roadway to another to form a top stress relief hole;

[0008] A cutting riser is constructed at a predetermined position at the starting end of the pillar mining. The cutting riser is used as a free surface, and vertical cutting grooves are formed by blasting in sequence.

[0009] A cross passage was excavated on one side of the lower plate of the pillar, connecting the cross passage to the two upper pressure relief drilling passages;

[0010] In this transverse tunnel, large-diameter parallel deep holes are constructed for blasting to create a pressure relief space;

[0011] The pillar mining area is divided according to the length of the pillar, and the cutting groove is used as the compensation space. Mining is carried out in the direction of the hanging wall to the footing wall.

[0012] After the mining of a single stope is completed, a backfilling retaining wall is constructed and the goaf is backfilled. Once the backfill reaches the predetermined strength, the adjacent stopes are mined until the entire inter-panel pillar is mined.

[0013] In some implementations, the process of dividing the pillar stope according to the pillar length, using the cutting groove as compensation space, and mining from the hanging wall to the footing wall, includes:

[0014] Construct upward fan-shaped medium-deep boreholes from the mining tunnel;

[0015] The blasting and mining are carried out from the upper plate to the lower plate.

[0016] In some implementations, after drilling upward fan-shaped deep holes from the receiving roadway and before blasting for backfilling, the process further includes:

[0017] The construction proceeds from the top-pressure-relief rock drilling tunnel to the downward fan-shaped large-diameter deep hole.

[0018] In some embodiments, in the blasting and mining from the upper plate to the lower plate, the blasting and mining method is row-by-row blasting, in which 3-5 rows are detonated at a time.

[0019] In some implementations, the preparation process includes:

[0020] At the bottom of the pillar between the panels during the waiting-to-be-mined stage, the receiving roadway, the exit roadway, and the exit access road connecting the two are constructed to form the bottom ore extraction system.

[0021] In some embodiments, after constructing a large-diameter parallel deep hole in the transverse tunnel and blasting to create a pressure relief space, the method further includes:

[0022] After all the ore in the depressurization space is released, an arched reinforced concrete retaining wall is immediately constructed in the depressurization space.

[0023] In some embodiments, the width of the concrete retaining wall is 0.5 meters.

[0024] In some embodiments, during the construction of large-diameter parallel deep holes in the transverse tunnel and the subsequent blasting to create a pressure relief space, the large-diameter parallel deep holes are constructed using decoupled charge blasting.

[0025] In some implementations, when dividing the pillar stope, the stope length is 50-60 meters, and the stope width is the same as the pillar width.

[0026] In some embodiments, during the process of dividing the mining area according to the length of the pillar, using the cutting groove as the compensation space, and mining from the hanging wall to the footwall, a peach-shaped pillar is reserved at the bottom of the mining area.

[0027] This application achieves the release of vertical stress at the top of the pillar by constructing two stress-relieving drilling tunnels and drilling long horizontal boreholes that penetrate the width of the pillar. Then, by constructing a cutting groove at the beginning and a stress-relieving space at the end in the horizontal direction, a horizontal two-way stress-relieving channel is formed. The stress-relieving hole at the top realizes the transfer of vertical stress and avoids rock bursts. The horizontal two-way stress relief makes the horizontal stress of the pillar controllable in both directions, prevents collapse, ensures that the mining process is a gradual and stable failure, provides safe conditions for mining operations, and realizes continuous control of ground pressure, ensuring the overall stability of the mining area. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of a deep, high-bearing, ultra-large inter-panel pillar bidirectional combined decompression stage mining method provided in the embodiments of this application;

[0029] Figure 2 This is a schematic diagram of the IV-IV cross-section structure of a deep, high-bearing, ultra-large inter-panel pillar bidirectional combined decompression stage mining method provided in the embodiments of this application;

[0030] Figure 3 This is a schematic diagram of the II-II cross-sectional structure of a deep, high-bearing, ultra-large inter-panel pillar bidirectional combined decompression stage mining method provided in the embodiments of this application;

[0031] Figure 4 This is a V-V cross-sectional structural diagram of a deep, high-bearing, ultra-large inter-panel pillar bidirectional combined decompression stage mining method provided in the embodiments of this application;

[0032] Figure 5 This is a schematic diagram of the III-III cross-sectional structure of a deep, high-bearing, ultra-large inter-disk pillar bidirectional combined decompression stage mining method provided in the embodiments of this application.

[0033] Explanation of reference numerals in the attached diagram: 1. Filling body; 2. Top pressure relief drilling tunnel; 3. Top pressure relief hole; 4. Panel column; 5. Downward large-diameter deep hole of the main blasting; 6. Upward medium-deep hole of the main blasting; 7. Bottom receiving tunnel; 8. Peach-shaped pillar; 9. Bottom ore extraction tunnel; 10. Lower surrounding rock; 11. Main blast hole; 12. Cutting riser; 13. Connecting tunnel of the top pressure relief drilling tunnel; 14. Pressure relief space; 15. Pressure relief groove; 16. Bottom ore extraction access; 17. Downward large-diameter deep hole of the pre-splitting blasting. Detailed Implementation

[0034] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0036] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0037] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0039] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0040] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0041] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0043] Reference Figures 1 to 5 A deep, high-bearing, ultra-large inter-panel pillar bidirectional combined decompression stage mining method, comprising:

[0044] S10. Arrange the mining preparation project; The purpose of this step is to build a complete bottom ore extraction system at the bottom of the pillar to meet the operating requirements of the ore extraction equipment, while ensuring ventilation conditions, and laying the foundation for subsequent ore extraction operations.

[0045] For example, refer to Figure 1 The plate section column 4 is located between the two filling bodies 1. Along the length direction of the plate section column 4, at the top of the lower surrounding rock 10 area below its bottom, inside the plate section column 4, the bottom ore exit roadway 9 with the excavation cross-section size adapted to the passage of mining transportation equipment is located. The direction of the bottom ore exit roadway 9 is parallel to the length direction of the plate section column 4, serving as the main transportation channel for centralized ore transportation.

[0046] Along the length of the bottom of the panel column 4, the bottom receiving roadway 7 is excavated parallel to the bottom ore exit roadway 9. The cross-sectional dimensions of the bottom receiving roadway 7 need to match the working space of the loader to receive the ore that falls from the blasting after the panel column 4 is mined, forming a buffer zone for receiving ore.

[0047] Reference Figure 2 Multiple bottom ore access roads 16 are excavated from the bottom ore access roadway 9 to the bottom ore receiving roadway 7. The spacing between the access roads is determined according to the operating coverage of the loader. The cross-sectional dimensions meet the turning and loading / unloading operation requirements of the loader, thereby constructing a three-level ore transportation route: receiving ore in the bottom ore receiving roadway 7, transferring ore in the bottom ore access roadway 16, and transporting ore out of the bottom ore access roadway 9.

[0048] A return air interface is set at the end of the bottom ore outlet roadway 9, and an air inlet interface is set at the beginning of the bottom ore receiving roadway 7. Local ventilators are configured to enhance airflow circulation, ultimately forming an airflow path from the bottom ore receiving roadway 7, the bottom ore outlet roadway 16, the bottom ore outlet roadway 9 to the return air system, meeting the ventilation, dust removal and blasting fume emission requirements of subsequent ore extraction operations.

[0049] S20. Construct two stress-relief drilling tunnels near the boundaries of the hanging wall and footwall at the top of the inter-panel pillar. The stress concentration zone at the top of the inter-panel pillar is distributed along the entire width of the pillar. If the stress-relief tunnels are only arranged locally, some areas will not be able to relieve stress. Place the two stress-relief drilling tunnels near the boundaries of the hanging wall and footwall, with a distance equal to the width of the pillar, to ensure that the subsequent horizontal long boreholes can penetrate the entire width of the pillar and avoid the formation of localized stress residue zones.

[0050] For example, refer to Figure 1 In the top area of ​​pillar 4 in the panel section, two construction starting points are determined, one near the upper boundary and the other near the lower boundary, so that the horizontal distance between the two starting points is consistent with the full width of pillar 4 in the panel section, ensuring that the roadway constructed subsequently can cover the stress concentration area of ​​the full width of the pillar.

[0051] Along the length of the panel section pillar 4, the top pressure relief rock drilling tunnel 2 is excavated from the starting point on the upper side of the positioning panel, and the tunnel direction is parallel to the length of the panel section pillar 4.

[0052] Along the length of column 4 in the plate section, another top pressure relief rock drilling tunnel is excavated from the starting point on the lower plate side, and the two tunnels are arranged in parallel.

[0053] S30. A horizontal long borehole, spanning the width of the pillar, is drilled from one stress-relief drilling roadway to another, forming a top stress-relief hole. Before mining, the top of the pillar bears the vertical concentrated stress of the overlying strata, accumulating a large amount of elastic strain energy, which easily triggers rock bursts. After the horizontal long borehole penetrates the top of the pillar, it is equivalent to forming an elastic strain energy release channel in the stress concentration area. The vertical stress originally acting on the top of the pillar will be transferred to the hanging wall and footwall on both sides of the borehole due to the weakening effect of the borehole, reducing the stress value at the top of the pillar to a safe threshold.

[0054] For example, refer to Figure 1In one of the top pressure relief drilling tunnels 2, a drilling rig adapted for horizontal long drilling is arranged, and the working direction of the rig is adjusted to be consistent with the width direction of the pillar 4 in the panel, so that the drilling path covers the stress concentration area at the top of the pillar.

[0055] Drill horizontally and vertically from the current top pressure relief drilling tunnel 2 to another top pressure relief drilling tunnel 2 until the borehole penetrates the full width of the top of the panel column 4 and connects to the other side of the top pressure relief drilling tunnel 2, forming a single top pressure relief hole 3.

[0056] Along the length of pillar 4 in the plate-plate section, the drilling steps are repeated at certain intervals to complete the construction of the top pressure relief holes 3 within the entire length of the pillar, forming a group of pressure relief holes covering the entire length of the pillar top. This creates a uniformly distributed elastic strain energy release channel at the top of pillar 4 in the plate-plate section, enabling the transfer of vertically concentrated stress to the surrounding rock of the upper and lower plate-plate sections.

[0057] S40. A cutting riser is constructed at a predetermined position at the starting end of pillar mining. Using the cutting riser as a free face, vertical cutting grooves are formed by sequential blasting. In addition to vertical stress, deep pillars also bear horizontal stress, which comes from the compression of the hanging wall and footwall. This horizontal stress is highly concentrated at the starting end of pillar mining, i.e., on the hanging wall side. The vertical cutting groove forms a free face at the starting end. According to the stress release principle of rock mechanics, the stress that originally acted on the pillar horizontally, from the hanging wall to the footwall, cannot continue to be concentrated at the starting end due to the existence of the free face. Instead, it transfers to the footwall side, away from the cutting groove, achieving pressure relief at the horizontal starting end and reducing the impact risk in the early stages of mining. Furthermore, the efficiency of mining blasting depends on the number of free faces; the more free faces, the easier the rock is to break.

[0058] For example, refer to Figure 2 and Figure 3 At the starting point of the mining of pillar 4 in the panel section, i.e. the upper side, a predetermined construction point is determined to be connected to the top pressure relief drilling roadway 2. This point needs to correspond to the initial free surface requirements of subsequent mining operations to ensure that the cutting groove can cover the horizontal stress concentration area of ​​the entire pillar height.

[0059] Using a riser drilling rig, drill upwards from the bottom ore-receiving tunnel 7 to the top pressure-relief drilling tunnel 2, forming a cutting riser 12; or drill downwards from the top pressure-relief drilling tunnel 2 to the bottom ore-receiving tunnel 7, forming a cutting riser 12.

[0060] Reference Figure 2 Using the cutting well 12 as the free surface, a cutting groove 15 is made in the plate section column 4. The cutting groove 15 is arranged along the width direction of the plate section column 4, thereby creating a free surface for horizontal stress release at the starting end of the plate section column 4, and forming a free surface for subsequent mining blasting, reducing the impact risk in the early stage of mining and improving blasting efficiency.

[0061] S50. A transverse tunnel is excavated on the footwall side of the pillar to connect the transverse tunnel with the two upper pressure relief drilling tunnels. The horizontal end pressure relief needs to form a pressure relief space along the entire width of the pillar on the footwall side. After the transverse tunnel connects the two pressure relief drilling tunnels, a transverse working corridor is formed. Drilling tools can be evenly arranged from the transverse tunnel along the width of the pillar to the deep holes to ensure that the pressure relief space formed by subsequent blasting can be continuously distributed along the width of the pillar, echoing the cutting groove at the starting end, and realizing horizontal bidirectional pressure relief.

[0062] For example, refer to Figure 3 In the lower side area of ​​the panel column 4, a construction starting point corresponding to the horizontal level of the two top pressure relief drilling tunnels 2 is determined. From this starting point, the top pressure relief drilling tunnel connecting tunnel 13, i.e., the transverse tunnel, is excavated along the width direction of the panel column 4. During the excavation process, the orientation of the top pressure relief drilling tunnel connecting tunnel 13 is kept parallel to the width direction of the panel column 4.

[0063] When the top pressure relief drilling tunnel 13 is excavated to the vertical projection position of the top pressure relief drilling tunnel 2, a connecting opening is excavated to form a through working channel between the top pressure relief drilling tunnel 13 and the tunnel, ensuring that the drilling tools can enter the working area of ​​the tunnel from the top pressure relief drilling tunnel 13.

[0064] Complete the full connection between the top pressure relief drilling tunnel 13 and the two top pressure relief drilling tunnels 2 to form a transverse working corridor. This will create a transverse working channel covering the full width of the pillar on the lower side of the panel, providing basic engineering conditions for the deep hole construction of horizontal end pressure relief.

[0065] S60. Construct a large-diameter parallel deep hole in the transverse tunnel and blast it to create a pressure relief space;

[0066] The rock is broken within a predetermined range, creating a pressure relief space. This space forms a second free face on the footwall side of the pillar, which, in conjunction with the initial cutting groove, weakens the horizontal stress concentration from two directions, achieving bidirectional horizontal pressure relief.

[0067] Unidirectional stress relief can lead to uncontrolled horizontal deformation of the pillar, easily forming shear failure zones within the pillar. This can result in the entire pillar collapsing during mining, causing instability in the goaf. The starting cutting groove and the ending stress relief space form a bidirectional stress release channel, allowing horizontal stress to transfer simultaneously from both ends to the hanging wall and footwall. This prevents excessive stress concentration at one end, keeping the horizontal stress of the pillar within a safe threshold. This ensures bidirectional controllable horizontal deformation of the pillar, avoiding shear failure caused by unilateral deformation. It guarantees that the pillar remains in a gradual, stable failure state throughout the mining process from start to finish, preventing the risk of sudden collapse.

[0068] For example, refer to Figure 3Within the connecting roadway 13 of the top pressure relief drilling roadway 2, which connects two top pressure relief drilling roadways, the construction area for the large-diameter deep hole is determined along the width direction of the panel column 4. This area corresponds to the lower side of the panel column 4, ensuring that the subsequent pressure relief space can be continuously distributed along the entire width of the pillar and match the position of the horizontal two-way free face formed by the cutting groove at the starting end.

[0069] Reference Figure 4 A rock drilling rig is arranged in the top pressure relief rock drilling tunnel 13, and pre-splitting blasting downward large-diameter deep holes 17 are constructed evenly along the width direction of the panel section column 4, with the hole depth being consistent with the full height of the panel section column 4.

[0070] Reference Figure 4 and Figure 5 Using the top-pressure-relief drilling tunnel 13 as the working protective space, downward large-diameter deep holes are sequentially detonated to break the rock on the lower side of pillar 4 within a predetermined range, forming the end-pressure-relief space 14. After blasting, the broken ore is released through the working channel of the top-pressure-relief drilling tunnel 13, eliminating the risk of secondary stress concentration from residual ore. By relying on the top-pressure-relief drilling tunnel 13 to complete the downward deep hole construction and blasting, the end-pressure-relief space 14 is constructed on the lower side of pillar 4, providing bidirectional pressure relief guarantee for the stability of ground pressure during pillar mining.

[0071] S70. Divide the pillar mining area according to the pillar length, and use the cutting groove as the compensation space to mine the mining area one by one from the hanging wall to the footing wall.

[0072] S80. After the mining of a single stope is completed, a backfilling retaining wall is constructed and the goaf is backfilled. After the backfill reaches the predetermined strength, the adjacent stopes are mined until the entire inter-panel pillar is mined.

[0073] This application provides a deep, high-bearing, ultra-large inter-panel pillar bidirectional combined decompression stage mining method, including:

[0074] S10. Arrange the preparation work;

[0075] S20. Construct two pressure relief drilling tunnels at the top of the pillar between the stage blocks, near the boundaries of the upper and lower plates.

[0076] S30. Drill a horizontal long borehole through the width of the pillar from one of the pressure relief drilling roadways to another, forming a top pressure relief hole;

[0077] S40. Construct a cutting riser at a predetermined position at the starting end of the pillar mining, and use the cutting riser as a free surface to blast vertical cutting grooves in sequence.

[0078] S50. A cross passage is excavated on one side of the footwall of the pillar to connect the cross passage with the two upper pressure relief drilling passages.

[0079] S60. Construct a large-diameter parallel deep hole in the transverse tunnel and blast it to create a pressure relief space;

[0080] S70. Divide the pillar mining area according to the pillar length, and use the cutting groove as the compensation space to mine the mining area one by one from the hanging wall to the footing wall.

[0081] S80. After the mining of a single stope is completed, a backfilling retaining wall is constructed and the goaf is backfilled. After the backfill reaches the predetermined strength, the adjacent stopes are mined until the entire inter-panel pillar is mined.

[0082] By constructing two stress-relief drilling tunnels (S20 and S30) at the top of the pillar and drilling long horizontal boreholes that penetrate the width of the pillar, the vertical stress at the top is released. Then, by constructing a starting end cutting groove and an end stress-relief space in the horizontal direction (S40, S50, and S60), a horizontal two-way stress-relief channel is formed. The stress-relief hole at the top realizes vertical stress transfer and avoids rock bursts. The horizontal two-way stress relief makes the horizontal stress of the pillar controllable in both directions, preventing collapse and ensuring that the mining process is a gradual and stable failure. This provides safe conditions for mining operations and enables continuous control of ground pressure, ensuring the overall stability of the mining area.

[0083] In some implementations, the process of dividing the pillar stope according to the pillar length, using the cutting groove as compensation space, and mining from the hanging wall to the footing wall, includes:

[0084] S71. Construct upward fan-shaped medium-deep boreholes from the receiving tunnel;

[0085] The receiving roadway is located at the bottom of the pillar. From here, upward fan-shaped medium-deep holes are drilled. The fan-shaped boreholes can expand the coverage area and form a three-dimensional borehole network with the downward large-diameter deep holes in the upper part of the stope. This ensures that the ore in the stope is blasted and broken evenly and avoids the occurrence of blasting blind spots.

[0086] For example, refer to Figure 1 In the roof area of ​​the bottom receiving roadway 7, corresponding to the bottom projection range of the mining area to be mined, the starting point for the construction of the upward fan-shaped medium-deep hole is determined to ensure that the starting point covers the full width of the mining area, laying the foundation for the coverage of the subsequent drilling range.

[0087] A drilling rig is set up in the bottom receiving roadway 7, and the drilling arm of the rig is adjusted to an upward fan-shaped divergence angle so that the drilling direction is adapted to the stope height of the panel column 4, ensuring that the drilling can cover the middle and lower part of the stope.

[0088] Operate the rock drilling rig and drill upwards from the construction starting point of the bottom receiving tunnel 7. According to the set fan-shaped angle, hole depth and spacing, complete the construction of the upward medium-deep hole 6 of the positive blasting, forming an upward fan-shaped borehole group covering the entire width of the mining area.

[0089] S72. Blasting and mining are carried out from the upper plate to the lower plate.

[0090] In some implementations, after S71, when constructing upward fan-shaped medium-deep holes from the receiving roadway, and before S72, when blasting is carried out for mining, the following steps are also included:

[0091] S711, constructing a downward fan-shaped large-diameter deep hole from the top pressure relief rock drilling tunnel.

[0092] Reference Figure 1 The top pressure relief drilling tunnel 2 is located at the top of the panel column 4. From this tunnel, a large-diameter fan-shaped deep hole 5 is constructed downwards, and the boreholes radiate outwards in a fan shape, covering the middle and upper part of the mining area. Meanwhile, the upward-facing fan-shaped medium-deep hole 6 constructed by the bottom mining tunnel 7 covers the middle and lower part of the mining area.

[0093] Reference Figure 1 and Figure 2 The two together form a three-dimensional drilling network, namely the main row of blast holes 11, to ensure that the ore from the top to the bottom of the mining area is blasted and broken, avoiding the creation of blasting blind spots.

[0094] In some implementations, refer to Figure 1 In the blasting and mining process from the upper plate to the lower plate, the blasting and mining method is row-by-row blasting, with 3-5 rows blasted at a time.

[0095] In some implementations, refer to Figure 1 S60. After constructing a large-diameter parallel deep hole in the transverse tunnel and blasting to create a pressure relief space, this method also includes:

[0096] S61. After all the ore in the depressurization space has been released, immediately construct an arched reinforced concrete retaining wall in the depressurization space.

[0097] Reference Figure 4 and Figure 5 Once a pressure relief space is formed, the surrounding rock above it loses the support of the mine pillars and is prone to loosening and deformation. Arched reinforced concrete retaining walls utilize the mechanical advantages of the arch structure to support the surrounding rock around the void, limiting the expansion of the loosened area and preventing the void from collapsing. Without retaining wall support, the surrounding rock in the pressure relief space will continuously collapse due to stress release, causing the void to expand continuously. This could eventually lead to the overall instability of the surrounding rock in the upper panel or adjacent mine pillars, triggering a large-scale collapse.

[0098] In addition, retaining walls can serve as physical barriers to prevent surrounding rock fragments and falling rocks from the empty area into the bottom mining roadway or work area, thus avoiding damage to equipment and injury to personnel, and creating a safe working environment for subsequent mining and mining in adjacent mining areas.

[0099] In addition, bottom ore extraction roadways, such as bottom receiving roadways and ore extraction access roads, are the core transportation channels for pillar mining. Retaining walls can prevent the deformation of the surrounding rock in the goaf from being transmitted to the roadway, ensuring the stability of the roadway structure, avoiding roadway blockage or collapse due to goaf instability, and ensuring the continuity of ore extraction operations.

[0100] In some implementations, the width of the concrete retaining wall is 0.5 meters.

[0101] In some implementations, large-diameter parallel deep holes are constructed in the transverse tunnel, and blasting is carried out to create a pressure relief space. The large-diameter parallel deep holes are blasted using decoupled explosive charges.

[0102] In some implementations, when dividing the ore pillar stope, the stope length is 50-60 meters, and the stope width is the same as the pillar width.

[0103] In some implementations, refer to Figure 1 and Figure 2 In S70, the pillar mining area is divided according to the length of the pillar. The cutting groove is used as the compensation space. The mining is carried out from the hanging wall to the footing wall, and a peach-shaped pillar 8 is reserved at the bottom of the mining area during the mining process.

[0104] The above description is merely a specific embodiment of this application, but the scope of protection of this invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in this invention, and within the spirit and principles of this invention, should be covered within the scope of protection of this invention.

[0105] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for mining deep, high-bearing, ultra-large inter-panel pillars with bidirectional combined decompression stage, characterized in that, include: Arrange the preparation work; At the top of the pillar between the two sections, near the boundary between the upper and lower plates, two stress relief drilling tunnels are constructed to connect the upper and lower plates. The two stress relief drilling tunnels are located at the boundary of the pillar. A horizontal long borehole, penetrating the width of the pillar, is drilled from one stress relief drilling roadway to another to form a top stress relief hole; A cutting riser is constructed at a predetermined position at the starting end of the pillar mining. The cutting riser is used as a free surface, and vertical cutting grooves are formed by blasting in sequence. A cross passage was excavated on one side of the footwall of the pillar, connecting the cross passage to the two upper pressure relief drilling passages; In this transverse tunnel, large-diameter parallel deep holes are constructed for blasting to create a pressure relief space; The pillar mining area is divided according to the length of the pillar. The cutting groove is used as the compensation space, and mining is carried out in the direction from the footwall to the hanging wall. Specifically, this includes: constructing large-diameter deep holes in the downward fan shape from the top pressure relief drilling roadway; constructing medium-deep holes in the upward fan shape from the receiving roadway; and blasting mining from the footwall to the hanging wall. After the mining of a single stope is completed, a backfilling retaining wall is constructed and the goaf is backfilled. Once the backfill reaches the predetermined strength, the adjacent stopes are mined until the entire inter-panel pillar is mined.

2. The deep, high-bearing, ultra-large inter-disk pillar bidirectional combined decompression stage mining method according to claim 1, characterized in that, In the blasting and mining process from the upper plate to the lower plate, the blasting and mining method is row-by-row blasting, in which 3-5 rows are detonated at a time.

3. The deep, high-bearing, ultra-large inter-disk pillar bidirectional combined decompression stage mining method according to claim 1, characterized in that, The preparation and preparation work includes: At the bottom of the pillar between the panels during the waiting-to-be-mined stage, the receiving roadway, the exit roadway, and the exit access road connecting the two are constructed to form the bottom ore extraction system.

4. The deep, high-bearing, ultra-large inter-disk pillar bidirectional combined decompression stage mining method according to claim 1, characterized in that, After constructing a large-diameter parallel deep hole in the transverse tunnel and blasting it to create a pressure relief space, this method further includes: After all the ore in the depressurization space is released, an arched reinforced concrete retaining wall is immediately constructed in the depressurization space.

5. The deep, high-bearing, ultra-large inter-disk pillar bidirectional combined decompression stage mining method according to claim 4, characterized in that, The width of the concrete retaining wall is 0.5 meters.

6. The deep, high-bearing, ultra-large inter-disk pillar bidirectional combined decompression stage mining method according to claim 1, characterized in that, In the construction of large-diameter parallel deep holes in the transverse tunnel, blasting is carried out to form a pressure relief space. The large-diameter parallel deep holes are constructed using decoupled charge blasting.

7. The deep, high-bearing, ultra-large inter-disk pillar bidirectional combined decompression stage mining method according to claim 1, characterized in that, When dividing the ore pillar stope, the stope length is 50-60 meters, and the stope width is the same as the pillar width.

8. The deep, high-bearing, ultra-large inter-disk pillar bidirectional combined decompression stage mining method according to claim 1, characterized in that, In the process of dividing the mining area according to the length of the pillar, using the cutting groove as the compensation space, and mining from the hanging wall to the footwall, a peach-shaped pillar is reserved at the bottom of the mining area during the mining process.

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