Method for opening the first mining layer mining route in the extremely broken rock route filling mining method

Abstract

The present application provides a method for opening the first mining layer access road of the extremely broken ore and rock access filling mining method, which belongs to the field of mining, wherein the method for opening the first mining layer access road of the extremely broken ore and rock access filling mining method includes the following steps: constructing advance grouting anchor rods, excavating layered transport tunnels, and sequentially performing one-time concrete spraying, constructing cement mortar anchor rods, laying metal mesh, laying steel belts, secondary concrete spraying, and laying the first steel arch frame in the layered transport tunnel; the first steel arch frame includes a first column and a first arch ring; a rectangular hole is set on the side of the first arch ring close to the access road to be recovered, and reinforcing steel is inserted into the rectangular hole to connect all the first steel arch frames; the height of the rectangular hole is higher than the height of the rough section of the access road to be recovered; the first column close to the opening of the access road to be recovered and the part of the first arch ring below the rough section of the access road to be recovered are removed, and the access road to be recovered is mined. The present application can ensure the safe support of the layered transport tunnel and the safety and stability during construction at the opening of the access road to be recovered.

Description

Technical Field

[0001] The present application relates to the field of mining technology, and in particular to a method for opening a first-layer mining access in an extremely broken ore rock access filling mining method. Background Art

[0002] To ensure safe mining, most highly fractured, medium-thick, and thicker ore bodies are mined using the downward approach and backfill method. In practical applications, the construction of the initial mining layer is crucial, as it determines the smooth transition to the next layer of mining throughout the approach area. In extremely fractured rock, the surrounding rock has poor self-stabilization capabilities. Simple shotcrete or shotcrete-bolt support methods are ineffective in effectively supporting the construction tunnel, making it difficult to ensure safety and stability, posing significant safety risks. Although the currently used combined support method of "sprayed anchor net + steel belt + steel arch frame" can provide safe and stable support for the layered transport tunnels in the first mining layer, when the mining approach is constructed in the first mining layer, the support measures at the junction of the layered transport tunnel and the approach opening need to be temporarily dismantled. Before the mining approach is constructed for a certain distance and high-strength active support is carried out, the approach opening is affected by the removal of support measures such as steel arch frames, the support strength is greatly reduced, the safety risk is increased, and roof collapse occurs frequently. Not only does it pose a safety hazard, but the subsequent remediation is time-consuming and difficult, which has become a major problem that plagues the safe and efficient production of mines. Summary of the Invention

[0003] In view of the technical problems existing in the background technology, the present application provides a method for opening the first mining layer recovery route in the extremely broken ore rock route filling mining method. By optimizing the support structure of the layered transport tunnel, the safe support of the layered transport tunnel and the safety and stability of the construction of the recovery route opening position in the layered transport tunnel are guaranteed.

[0004] The present application provides a method for opening a first-layer mining access in an extremely broken ore access filling mining method, comprising the following steps:

[0005] S1. Pre-grouting anchor bolts are constructed in the primary mining layer, and a layered transport tunnel is excavated. In the layered transport tunnel, a first shotcrete is sprayed, cement mortar anchor bolts are constructed, metal mesh is laid, steel belts are laid, a second shotcrete is sprayed, and a first steel arch frame is laid. The first steel arch frame includes a set of first columns and a first arch ring connected to the first columns.

[0006] S2. A rectangular hole is provided on one side of the first arch ring close to the access road to be mined, and reinforcing steel is inserted into the rectangular hole to connect all the first steel arches; the height of the rectangular hole is higher than the height of the rough cross-section of the access road to be mined;

[0007] S3. Remove the first column near the opening of the mining access and the portion of the first arch ring below the rough section of the mining access, and mine the mining access.

[0008] In the technical solution of the embodiment of the present application, first, the support of the layered transportation tunnel of the first mining layer is achieved by adopting the combined support method of "advance grouting + full-section sprayed anchor net + steel belt connection + steel arch frame", so as to ensure the long-term safety and stability of the layered transportation tunnel of the first mining layer; then, a rectangular hole is set on the side of the first arch ring close to the access road to be mined, and reinforcing steel is inserted into the rectangular hole to connect all the first steel arch frames, so as to ensure that the access road to be mined can be opened smoothly, and the stability of the opening of the access road to be mined is guaranteed, thereby realizing the safe and efficient mining of the first mining layer of the downward access mining method under extremely broken ore and rock conditions.

[0009] In some embodiments, the first arch ring includes a first half arch ring lower than the gross cross-sectional height of the access road to be mined and a second half arch ring higher than the gross cross-sectional height of the access road to be mined, and the rectangular hole is provided on the second half arch ring.

[0010] In this embodiment, by setting the first arch ring into two parts, when the mining access needs to be opened, only the first column and the first half arch ring need to be removed, so that the second half arch ring can still play a supporting role; by setting a rectangular hole on the second half arch ring, favorable conditions are provided for the reinforcement of the reinforcing steel.

[0011] In some embodiments, a first threaded nut overlapping structure is provided between the first column and the first arch ring; and a second threaded nut overlapping structure is provided between the first half arch ring and the second half arch ring.

[0012] In this embodiment, by setting the first threaded nut overlapping structure, the disassembly and installation of the first column and the first arch ring are facilitated; by setting the second threaded nut overlapping structure, the disassembly and installation of the first half arch ring and the second half arch ring are facilitated.

[0013] In some embodiments, the height of the rectangular hole is 8-12 cm higher than the height of the second threaded nut overlap structure; the length of the rectangular hole is 1-2 cm larger than the length of the reinforcing steel cross section, and the width of the rectangular hole is 1-2 cm larger than the width of the reinforcing steel cross section.

[0014] In this embodiment, by setting the height of the rectangular hole to be higher than the height of the second threaded nut overlap structure, the reinforcing steel is located at an appropriate position, thereby improving the support strength of the support structure; by setting the size of the rectangular hole to be slightly larger than the size of the cross-section of the reinforcing steel, while facilitating the insertion of the reinforcing steel into the rectangular hole, firm contact between the reinforcing steel and the rectangular hole can be achieved as much as possible.

[0015] In some embodiments, the distance between adjacent first steel arches is 0.8-1.2 m.

[0016] In this embodiment, by reasonably controlling the distance between adjacent first steel arch frames, stable support is achieved while avoiding the increase in support cost due to over-density of the first steel arch frames.

[0017] In some embodiments, the mining of the to-be-mined access road in step S3 is specifically as follows: first, an advanced round steel anchor rod is constructed in the to-be-mined access road, and then mining and supporting are performed simultaneously; the support includes spraying concrete once, constructing the cement mortar anchor rod, laying the metal mesh, laying the steel belt, laying the second steel arch frame, and spraying concrete twice in the to-be-mined access road.

[0018] In this embodiment, after the approach to the mining route is successfully formed, the "advance support + shotcrete net + steel belt + steel arch support" is used to achieve stable support of the approach to the mining route, thereby achieving safe and efficient mining of the approach to the mining route.

[0019] In some embodiments, the diameter of the advanced round steel anchor rod is 30-35 mm, the length is 3.0-3.5 m, the circumferential spacing is 250-350 mm, and the external insertion angle is 3°-5°; the thickness of the one-time shotcrete is 25-35 mm, and the strength is C15; the cement mortar anchor rod is arranged perpendicular to the wall of the access road to be mined, the diameter of the cement mortar anchor rod is 15-25 mm, the length is 1.8-2.2 m, and the mesh size is (0.8-1 .2)m×(0.8-1.2)m; the mesh size of the metal mesh is (80-120)mm×(80-120)mm, and the size is (1.8-2.2)m×(0.8-1.2)m; the steel strip is a W-shaped steel strip with a length of 2.0-2.5m, a width of 200-250mm, and a thickness of 4-6mm. The spacing between adjacent steel strips is 0.8-1.2m; the thickness of the secondary sprayed concrete is 25-35mm.

[0020] In this embodiment, by reasonably setting the parameters of each support component in the mining access, safe support of the mining access is achieved, providing favorable conditions for safe and efficient mining of the mining access.

[0021] In some embodiments, in step S1, the outer diameter of the advance grouting anchor rod is 30-35 mm, the wall thickness is 5-7 mm, the length is 3.0-3.5 m, the circumferential spacing is 250-350 mm, and the external insertion angle is 3°-5°; the thickness of the primary sprayed concrete is 25-35 mm, and the strength is C15; the cement mortar anchor rod is arranged perpendicular to the wall of the layered transport tunnel, the diameter of the cement mortar anchor rod is 15-25 mm, the length is 1.8-2.2 m, and the mesh size is (0.8-1.2) m×(0.8-1.2) m; the mesh size of the metal mesh is (80-120) mm×(80-120) mm, and the size is (1.8-2.2) m×(0.8-1.2) m; the spacing between adjacent steel belts is 0.8-1.2 m; the thickness of the secondary sprayed concrete is 25-35 mm.

[0022] In this embodiment, by reasonably setting the parameters of each support component in the layered transport tunnel, long-term safe and stable support of the layered transport tunnel is achieved.

[0023] In some embodiments, a tray is provided at one end of the cement mortar anchor rod close to the layered transport tunnel or the access road to be mined.

[0024] In this embodiment, a tray is provided at one end of the cement mortar anchor rod close to the tunnel, and the tray is used to reinforce the cement mortar anchor rod, the metal mesh and the steel belt, thereby improving the support effect.

[0025] In some embodiments, the gross cross-sectional dimensions of the layered transport tunnel are 4.6m×3.9m, and the net cross-sectional dimensions after support are 4×3.6m; the gross cross-sectional dimensions of the access road to be mined are 3.8m×3.3m, and the net cross-sectional dimensions after support are 3.2×3.0m.

[0026] In this embodiment, by reasonably setting the dimensions of the gross cross-section and the net cross-section after support of the layered transport tunnel, smooth transportation of ore is facilitated while achieving firm support; by reasonably setting the dimensions of the gross cross-section and the net cross-section after support of the access road to be mined, favorable conditions are provided for the reinforcement of the reinforcing steel, thereby achieving smooth and safe opening of the access road to be mined and efficient and safe mining.

[0027] 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

[0028] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0029] Figure 1 This is a schematic diagram of the layout of the first mining layer in the panel area of ​​the downward approach filling mining method in the embodiment of this application;

[0030] Figure 2 This is a front view of the entrance opening of the layered transport tunnel in the embodiment of the present application;

[0031] Figure 3 for Figure 2 Schematic diagram of section II;

[0032] Figure 4 for Figure 2 Schematic diagram of section II-II;

[0033] Figure 5 This is a full cross-sectional view of the access road to be mined in the embodiment of this application;

[0034] Figure 6 This is a schematic diagram of the first threaded nut overlapping structure in an embodiment of the present application;

[0035] Figure 7 This is a schematic diagram of the "full-section shotcrete mesh + steel belt connection" of the layered transport tunnel in the embodiment of this application;

[0036] Figure 8 for Figure 3 Enlarged view of point A in the middle;

[0037] Explanation of the accompanying reference numerals: 1-advance grouting anchor rod; 2-layered transport tunnel; 3-cement mortar anchor rod; 4-metal mesh; 5-steel belt; 6-first steel arch frame; 7-reinforcement steel; 8-approach road to be mined; 9-advance round steel anchor rod; 10-first threaded nut overlapping structure; 11-second threaded nut overlapping structure; 12-extra-vein transport tunnel; 13-second steel arch frame; 14-tray; 15-surrounding rock; 16-panel connecting road; 17-transport road; 61-first column; 62-first arch ring; 63-rectangular hole; 101-first T-shaped bolt; 102-first nut; 103-first small gasket; 104-first large gasket; 131-second column; 132-second arch ring. DETAILED DESCRIPTION

[0038] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0040] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0041] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "length", "width", "thickness", "up", "down", "vertical", "horizontal", "top", and "bottom" are based on the orientations or positional relationships shown in the accompanying drawings. They 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 device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the embodiments of the present application.

[0043] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0044] Most of the extremely fractured medium and thick ores are mined by the downward approach filling mining method. Under the conditions of extremely fractured ore and rock, the self-stabilizing ability of the surrounding rock is poor, and the combined support method of "sprayed anchor net + steel belt + steel arch frame" is usually adopted. Although this support method can provide safe and stable support for the layered transportation tunnel of the first mining layer, when the mining approach in the first mining layer is constructed, it is necessary to temporarily remove the support measures at the junction of the layered transportation tunnel and the approach opening. When the current combined support method of "sprayed anchor net + steel belt + steel arch frame" temporarily removes the support measures at the junction of the layered transportation tunnel and the approach opening, there is a risk of roof collapse at the approach opening.

[0045] In order to solve the technical problem that when the support measures at the junction of the layered transport tunnel and the access opening are temporarily removed, the risk of roof collapse at the access opening is likely to occur, the present application provides a method for opening the first mining layer access in the extremely broken ore and rock access filling mining method, wherein firstly, the layered transport tunnel of the first mining layer is supported by adopting a combined support method of "advance grouting + full-section shotcrete mesh + steel belt connection + steel arch frame", ensuring the long-term safety and stability of the layered transport tunnel of the first mining layer; then, a rectangular hole is set on the side of the first arch ring close to the access to be mined, and reinforcing steel is inserted into the rectangular hole to connect all the first steel arch frames, ensuring that the access to be mined can be opened smoothly, ensuring the stability of the opening of the access to be mined, and realizing the safe and efficient mining of the first mining layer of the downward access mining method under extremely broken ore and rock conditions. This method shows excellent adaptability in extremely broken ore and rock and complex geological conditions, and has broad application prospects and promotion value.

[0046] Please refer to Figure 1 , this application adopts the downward approach filling mining method for mining. During the mining process, in order to rationally plan the production area and optimize the production system, the ore body is divided into panels, and the panels are used as units for mining, and panel connecting roads 16 are set between adjacent panels. Specifically, an off-vein transport tunnel 12 is constructed in the surrounding rock 15 outside the panel along the direction of the ore body, and a layered transport tunnel 2 is constructed along the direction of the ore body inside the panel. Several mining routes 8 are divided in the panel, and the ore is mined from the layered transport tunnel 2 to the mining route 8. The mining route 8 is arranged perpendicular to the direction of the ore body. Combined with the actual production situation, the route division and production capacity requirements are comprehensively considered, and the mining method of mining one every other or one every other is adopted. In order to facilitate transportation, a transport road 17 can be set in the panel, and the ore is transported to the off-vein transport road 12 for unloading through the layered transport tunnel 2, the panel connecting road 16 and the transport road 17.

[0047] Please refer to Figure 2-Figure 4 , which is a method for opening a first-layer mining route in an extremely broken ore route filling mining method provided in an embodiment of the present application, comprises the following steps:

[0048] S1. Construct advance grouting anchor rods 1 in the first mining layer, excavate the layered transport tunnel 2, and carry out the first concrete spraying, construction of cement mortar anchor rods 3, laying of metal mesh 4, laying of steel belts 5, second concrete spraying, and laying of the first steel arch frame 6 in the layered transport tunnel 2 in sequence; the first steel arch frame 6 includes a group of first columns 61 and a first arch ring 62 connected to the first columns 61. Specifically, advance drilling construction is first carried out at the opening position of the layered transport tunnel 2 along the extrapolated angle outside the excavation contour line toward the front of the arch. After the drilling construction is completed, the advance grouting anchor rod 1 is installed to form pre-anchoring, and then grouting construction is carried out. After the slurry solidifies, the layered transport tunnel 2 is excavated; after the layered transport tunnel 2 is excavated, ventilation and slag removal are immediately carried out, and then a concrete spraying operation is carried out on the entire section; after the first concrete spraying is completed, the cement mortar anchor rod 3 is drilled, and after the cement mortar anchor rod 3 is inserted into the hole, the metal mesh 4 and the steel belt 5 are laid. The steel belt 5 is set along the direction of the layered transport tunnel 2, and the steel belt 5 is overlapped with the cement mortar anchor rod 3, thereby completing the "spray anchor net + steel belt" construction, and then a secondary concrete spraying operation is carried out to ensure that the surface of the secondary concrete spraying layer is relatively flat, and that the supporting components such as the cement mortar anchor rod 3, the metal mesh 4 and the steel belt 5 are basically not exposed, meeting the support safety standard; then the first steel arch frame 6 is installed. The advanced grouting anchor rod 1 is a hollow seamless steel pipe. The first column 61 and the first arch ring 62 are both made of 25a I-steel.

[0049] S2. A rectangular hole 63 is set on one side of the first arch ring 62 close to the access road 8 to be mined, and a reinforcing steel 7 is inserted into the rectangular hole 63 to connect all the first steel arch frames 6. If the access roads 8 to be mined are set on both sides of the layered transport tunnel 2, it is necessary to set rectangular holes 63 on both sides of the first arch ring 62 close to the access roads 8 to be mined, and insert reinforcing steel 7 into the rectangular holes 63 on both sides to connect all the first steel arch frames 6; the height of the rectangular hole 63 is higher than the height of the gross cross-section of the access road 8 to be mined. Specifically, a rectangular hole 63 is formed on the first arch ring 62 by cutting, and the reinforcing steel 7 is inserted into the rectangular hole 63 to connect all the first steel arch frames 6. The reinforcing steel 7 uses an I-beam with a model number of 16.

[0050] S3. Remove the first column 61 near the opening of the mining access 8 and the portion of the first arch ring 62 below the gross cross-section of the mining access 8 to be mined, and mine the mining access 8. Specifically, when the mining access 8 is ready to be opened, remove the first column 61 within the coverage of the gross cross-section of the mining access 8 and the portion of the first arch ring 62 below the gross cross-section of the mining access 8 to be mined. At this time, the remaining portion of the first arch ring 62 at the top of the opening of the mining access 8 to be mined is connected to the first steel arch frame 6 that has not been removed in other parts through the reinforcing steel 7 to form an integrated structure.

[0051] In the technical solution of the embodiment of the present application, the combined support method of "advance grouting + full-section sprayed anchor net + steel belt connection + steel arch frame" is first adopted to realize the support of the layered transport tunnel 2 of the first mining layer. This support method has good active support effect and high support strength, and can ensure the long-term safety and stability of the layered transport tunnel 2 of the first mining layer; then a rectangular hole 63 is set on the side of the first arch ring 62 close to the mining access road 8, and reinforcing steel 7 is inserted into the rectangular hole 63 to connect all the first steel arch frames 6, so that all the first steel arch frames 6 form an integrated structure. Such a setting, on the one hand, enhances the overall support strength of the layered transport tunnel 2, and at the same time helps to enlarge the step distance of the first steel arch frame 6 and optimize the support cost; on the other hand, when the mining access road 8 is ready to be opened, the first column 61 within the coverage range of the gross section of the mining access road 8 and the part of the first arch ring 62 below the gross section of the mining access road 8 are removed. At this time The remaining portion of the first arch ring 62 at the top of the opening of the mining access 8 is connected to the first steel arch frame 6 that has not been removed from other parts by the reinforcing steel 7 to form an integrated structure, so that the roof at the opening of the mining access 8 forms an integral joint force plane, and can evenly distribute the pressure of the roof of the mining access 8 at the first steel arch frame 6 of the disassembled portion of the first arch ring 62 to the adjacent complete first steel arch frame 6, avoiding local pressure concentration causing the roof of the mining access 8 to collapse, ensuring that the mining access 8 can smoothly open the entrance, ensuring the stability of the opening of the mining access 8, and realizing the safe and efficient mining of the first mining layer of the downward mining method under extremely broken ore and rock conditions; at the same time, it can prevent the remaining portion of the first arch ring 62 at the top of the opening of the mining access 8 from falling, so that it can still play a good supporting role, so that the roof of the opening position of the mining access 8 to be recovered remains stable, and further realizes the safe and efficient mining of the first mining layer. That is, the present application ensures the safety and stability of the construction of the opening position of the mining access 8 in the stratified transport tunnel 2 by optimizing the support structure of the stratified transport tunnel 2.

[0052] Furthermore, in the embodiments of the present application, Figure 3 As shown, the first arch ring 62 includes a first half arch ring that is lower than the gross cross-sectional height of the to-be-mined access road 8 and a second half arch ring that is higher than the gross cross-sectional height of the to-be-mined access road 8. The rectangular hole 63 is provided in the second half arch ring. If the to-be-mined access roads 8 are provided on both sides of the layered transport roadway 2, the portions on both sides of the first arch ring 62 that are lower than the gross cross-sectional height of the to-be-mined access roads 8 are both referred to as first half arch rings, i.e., the first arch ring 62 includes two first half arch rings and one second half arch ring.

[0053] In the technical solution of the embodiment of the present application, by setting the first arch ring 62 to be a first half arch ring lower than the gross cross-section height of the access road 8 to be mined and a second half arch ring higher than the gross cross-section height of the access road 8 to be mined, when the access road 8 to be mined needs to be opened, only the first column 61 and the first half arch ring need to be removed, so that the second half arch ring can still play a supporting role. By setting the rectangular hole 63 on the second half arch ring, even when the first half arch ring is removed, it can still be ensured that the reinforcement steel 7 is present at the top of the layered transport tunnel 2, and it can be connected to the intact first steel arch frame 6 that has not been removed from other parts to form an integrated structure, thereby improving the support effect and achieving the smooth opening and efficient mining of the access road 8 to be mined.

[0054] Furthermore, in the embodiments of the present application, Figure 3 As shown, a first threaded nut overlapping structure 10 is provided between the first column 61 and the first arch ring 62; a second threaded nut overlapping structure 11 is provided between the first half arch ring and the second half arch ring. Figure 6 As shown, the first threaded nut overlapping structure 10 includes a first T-shaped bolt 101 and a first nut 102. The connection between the first column 61 and the first arch ring 62 is provided with a through hole. The first T-shaped bolt 101 passes through the through holes set on the first column 61 and the first arch ring 62, and is fixed by the first nut 102 to realize the detachable connection between the first column 61 and the first arch ring 62; a first large gasket 104 is provided at the contact between the first T-shaped bolt 101 and the first column 61; a first small gasket 103 is provided at the contact between the first nut 102 and the first arch ring 62. The structure of the second threaded nut overlapping structure 11 is similar to that of the first threaded nut overlapping structure 10. Specifically, the second threaded nut overlapping structure 11 includes a second T-shaped bolt and a second nut. The connection between the first semi-arch ring and the second semi-arch ring is provided with a through hole. The second T-shaped bolt passes through the through holes set on the first semi-arch ring and the second semi-arch ring, and is fixed by the second nut to realize the detachable connection between the first semi-arch ring and the second semi-arch ring; a second large gasket is provided at the contact point between the second T-shaped bolt and the first semi-arch ring; and a second small gasket is provided at the contact point between the second nut and the second semi-arch ring.

[0055] In the technical solution of the embodiment of the present application, by providing a first threaded nut overlapping structure 10 at the connection between the first column 61 and the first arch ring 62, the disassembly and installation of the first column 61 and the first arch ring 62 are facilitated. By providing a second threaded nut overlapping structure 11 at the connection between the first half arch ring and the second half arch ring, the disassembly and installation of the first half arch ring and the second half arch ring are facilitated. When the access road 8 to be mined is ready to be opened, the first column 61 and the first half arch ring are quickly dismantled by the first threaded nut overlapping structure 10 and the second threaded nut overlapping structure 11, thereby quickly realizing the opening and mining of the access road 8 to be mined.

[0056] Furthermore, in the embodiments of the present application, Figure 3 As shown, the height of the rectangular hole 63 is 8-12 cm higher than the height of the second threaded nut overlap structure 11; the length of the rectangular hole 63 is 1-2 cm greater than the length of the cross section of the reinforcing steel 7, and the width of the rectangular hole 63 is 1-2 cm greater than the width of the cross section of the reinforcing steel 7. Specifically, the length of the rectangular hole 63 is 170 mm and the width is 98 mm, while the cross section of the reinforcing steel 7 is 160 mm long and 88 mm wide.

[0057] In the technical solution of the embodiment of the present application, by setting the height of the rectangular hole 63 to be higher than the height of the second threaded nut overlap structure 11, the reinforcing steel 7 is positioned in an appropriate position, thereby improving the support strength of the support structure. By setting the size of the rectangular hole 63 to be slightly larger than the cross-sectional size of the reinforcing steel 7, while facilitating the insertion of the reinforcing steel 7 into the rectangular hole 63, it is possible to achieve a firm contact between the reinforcing steel 7 and the rectangular hole 63, thereby providing a better support function for the reinforcing steel 7. To further improve the firm contact between the reinforcing steel 7 and the rectangular hole 63, the rectangular hole 63 and the reinforcing steel 7 can be welded.

[0058] Furthermore, in the embodiments of the present application, Figure 2 As shown, the distance (i.e., pitch) between adjacent first steel arches 6 is 0.8-1.2 m, preferably 1 m. Specifically, in relatively fragmented areas, the spacing between adjacent first steel arches 6 can be appropriately reduced. The first arch ring 62 is machined to conform to the arch shape of the layered transport laneway 2.

[0059] In the technical solution of the embodiment of the present application, by reasonably controlling the distance between adjacent first steel arch frames 6, while achieving stable support, it is possible to avoid the first steel arch frames 6 being too dense and increasing the support cost.

[0060] Furthermore, in the embodiments of the present application, Figure 5As shown, in step S3, mining the access road 8 to be mined is specifically performed as follows: first, advance round steel anchor bolts 9 are constructed in the access road 8 to be mined, followed by simultaneous mining and support. This support includes, in sequence, a primary shotcrete installation, the construction of cement mortar anchor bolts 3, the laying of metal mesh 4, the laying of steel belts 5, the laying of a second steel arch 13, and a secondary shotcrete installation within the access road 8 to be mined. The access road 8 to be mined is a temporary construction project. After the access road 8 is constructed to its designed length, it will be backfilled. Therefore, advance support can be performed without grouting. The access road 8 to be mined can be mined normally according to the construction sequence of "advance pre-support + shotcrete anchor net + steel belt + steel arch support." Specifically, advance drilling construction is first carried out at the opening position of the mining access road 8 along the extrapolated angle outside the excavation contour line to the front of the arch. After the drilling construction is completed, the advance round steel anchor rod 9 is installed to form a pre-anchor; the mining access road 8 is mined and supported while mining. After mining a preset distance, ventilation and slag removal are immediately carried out, and then the rough section of the mining access road 8 is sprayed with concrete once. After the first spraying of concrete is completed, drilling construction of cement mortar anchor rod 3 is carried out. After the cement mortar anchor rod 3 is inserted into the hole, the metal mesh 4 and steel belt 5 are laid. The steel belt 5 is set along the direction of the mining access road 8. The steel belt 5 is overlapped with the cement mortar anchor rod 3, thereby completing the construction of "spray anchor mesh + steel belt", and then the second steel arch frame 13 is laid, and a second spraying operation is carried out to ensure that the surface of the secondary spraying concrete layer is relatively smooth, and that the supporting components such as the cement mortar anchor rod 3, metal mesh 4 and steel belt 5 are basically not exposed, meeting the support safety standard. The second steel arch frame 13 includes a group of second columns 131 and a second arch ring 132. The connection between the second columns 131 and the second arch ring 132 is provided with a first threaded nut overlapping structure 10; the second columns 131 and the second arch ring 132 are both made of I-beam with model 25a.

[0061] In the technical solution of the embodiment of the present application, after the entrance of the mining access road 8 is successfully formed, the stable support of the mining access road 8 is achieved through "advanced support + shotcrete net + steel belt + steel arch support", thereby achieving safe and efficient mining of the mining access road 8.

[0062] Furthermore, in the embodiments of the present application, Figure 5As shown, the diameter of the advanced round steel anchor rod 9 in the mining access road 8 is 30-35mm, the length is 3.0-3.5m, the circumferential spacing is 250-350mm, and the external insertion angle is 3°-5°. Preferably, the diameter of the advanced round steel anchor rod 9 is 32mm, the length is 3m, the circumferential spacing is 300mm, and the external insertion angle is 4°; the thickness of the one-time shotcrete is 25-35mm, preferably 30mm, and the strength is C15; the cement mortar anchor rod 3 is arranged perpendicular to the wall of the mining access road 8, the diameter of the cement mortar anchor rod 3 is 15-25mm, the length is 1.8-2.2m, and the mesh size is (0.8-1.2)m×(0.8-1.2)m. Preferably, the diameter of the cement mortar anchor rod 3 is 20 mm, a length of 2m, and a mesh size of 1m×1m; the mesh size of the metal mesh 4 is (80-120)mm×(80-120)mm, and the size is (1.8-2.2)m×(0.8-1.2)m. Preferably, the mesh size of the metal mesh 4 is 1m×1m, the size is 2m×1m, and the metal mesh 4 is welded with steel bars with a diameter of 8mm; the steel strip 5 is a W-shaped steel strip with a length of 2.0-2.5m, a width of 200-250mm, and a thickness of 4-6mm. Preferably, the steel strip 5 has a length of 2m, a width of 220mm, and a thickness of 5mm. The spacing between adjacent steel strips 5 is 0.8-1.2m, preferably 1m; the thickness of the secondary sprayed concrete is 25-35mm.

[0063] In the technical solution of the embodiment of the present application, by reasonably setting the parameters of the advance round steel anchor rod 9, cement mortar anchor rod 3, metal mesh 4, steel belt 5, primary concrete spraying and secondary concrete spraying, safe support of the mining access road 8 to be recovered is achieved, providing favorable conditions for the safe and efficient mining of the mining access road 8 to be recovered.

[0064] Furthermore, in the embodiments of the present application, Figure 3As shown, in step S1, the outer diameter of the advance grouting anchor rod 1 is 30-35mm, the wall thickness is 5-7mm, the length is 3.0-3.5m, the circumferential spacing is 250-350mm, and the external insertion angle is 3°-5°. Preferably, the outer diameter of the advance grouting anchor rod 1 is 32mm, the wall thickness is 6mm, the length is 3m, the circumferential spacing is 300mm, and the external insertion angle is 4°; the thickness of the one-time sprayed concrete is 25-35mm, preferably 30mm, and the strength is C15; the cement mortar anchor rod 3 is arranged perpendicular to the wall of the layered transport tunnel 2, the diameter of the cement mortar anchor rod 3 is 15-25mm, the length is 1.8-2.2m, and the mesh size is (0.8-1.2)m×(0.8-1.2)m. Preferably, the cement mortar anchor rod 3 has a diameter of 20mm, a length of 2m, and a mesh size of 1m×1m; the mesh size of the metal mesh 4 is (80-120)mm×(80-120)mmm, and the size is (1.8-2.2)m×(0.8-1.2)m. Preferably, the mesh size of the metal mesh 4 is 1m×1m, the size is 2m×1m, and the metal mesh 4 is welded with steel bars with a diameter of 8mm; the steel strip 5 is a W-shaped steel strip with a length of 2.0-2.5m, a width of 200-250mm, and a thickness of 4-6mm. Preferably, the steel strip 5 has a length of 2m, a width of 220mm, and a thickness of 5mm. The spacing between adjacent steel strips 5 is 0.8-1.2m, preferably 1m; the thickness of the secondary sprayed concrete is 25-35mm.

[0065] In the technical solution of the embodiment of the present application, by reasonably setting the parameters of the advance grouting anchor rod 1, cement mortar anchor rod 3, metal mesh 4, steel belt 5, primary concrete spraying and secondary concrete spraying, long-term safe and stable support of the layered transport tunnel 2 is achieved.

[0066] Furthermore, in the embodiments of the present application, Figure 7 As shown, a tray 14 is provided at one end of the cement mortar anchor rod 3 close to the layered transport tunnel 2 or the mining access road 8. Specifically, the tray 14 is installed at the end of the cement mortar anchor rod 3 close to the tunnel, and the tray 14 covers the metal mesh 4 and the steel belt 5.

[0067] In the technical solution of the embodiment of the present application, a tray 14 is set at one end of the cement mortar anchor rod 3 close to the tunnel, and the tray 14 is used to reinforce the cement mortar anchor rod 3, the metal mesh 4 and the steel belt 5, thereby improving the support effect.

[0068] Furthermore, in the embodiment of the present application, the gross cross-sectional dimensions of the layered transport tunnel 2 are 4.6m×3.9m, and the net cross-sectional dimensions after support are 4×3.6m; the gross cross-sectional dimensions of the mining access road 8 are 3.8m×3.3m, and the net cross-sectional dimensions after support are 3.2×3.0m.

[0069] In the technical solution of the embodiment of the present application, by rationally setting the gross cross-section and the net cross-section after support of the stratified transport roadway 2, smooth transportation of ore is facilitated while achieving firm support. By rationally setting the gross cross-section and the net cross-section after support of the mining access road 8 to be smaller than those of the stratified transport roadway 2, favorable conditions are provided for the reinforcement of the reinforcing steel 7, thereby achieving smooth and safe opening of the mining access road 8 and efficient and safe mining.

[0070] Please also refer to Figures 1 to 7 According to one or more embodiments of the present application, the present application first adopts the combined support method of "advance grouting + full-section sprayed anchor net + steel belt connection + steel arch frame" to realize the support of the layered transport tunnel 2 of the first mining layer, which can ensure the long-term safety and stability of the layered transport tunnel 2 of the first mining layer; then a rectangular hole 63 is set on the side of the first arch ring 62 close to the mining access road 8, and a reinforcing steel 7 is inserted into the rectangular hole 63 to connect all the first steel arch frames 6, which not only enhances the overall support strength of the layered transport tunnel 2, but also when the mining access road 8 is ready to open, the first steel arch frames 6 within the coverage of the gross section of the mining access road 8 are removed. When a column 61 and a part of the first arch ring 62 that is lower than the rough cross-section of the mining access 8 are connected, the top plate at the opening of the mining access 8 forms an integral joint force plane, ensuring that the mining access 8 can smoothly open the entrance, ensuring the stability of the opening of the mining access 8, and realizing the safe and efficient mining of the first mining layer of the downward mining method under extremely broken ore and rock conditions; by setting the first threaded nut overlapping structure 10 and the second threaded nut overlapping structure 11, the disassembly and installation of the first column 61 and the first arch ring 62, the first half arch ring and the second half arch ring are facilitated, thereby quickly realizing the opening and mining of the mining access 8.

[0071] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for opening a first-layer mining route in a very-fragmented rock route filling mining method, characterized in that: The following steps are involved: S1. Pre-grouting anchor bolts are constructed in the primary mining layer, and a layered transport tunnel is excavated. In the layered transport tunnel, a first shotcrete spraying, cement mortar anchor bolt construction, metal mesh laying, steel belt laying, a second shotcrete spraying, and a first steel arch frame are sequentially performed; the first steel arch frame includes a set of first columns and a first arch ring connected to the first columns; a first threaded nut overlap structure is provided between the first columns and the first arch ring; S2. A rectangular hole is provided on a side of the first arch ring close to the access road to be mined, and a reinforcing steel is inserted into the rectangular hole to connect all the first steel arch frames; the height of the rectangular hole is higher than the height of the gross cross-section of the access road to be mined; the first arch ring includes a first half arch ring lower than the gross cross-section height of the access road to be mined and a second half arch ring higher than the gross cross-section height of the access road to be mined, and the rectangular hole is provided on the second half arch ring; a second threaded nut overlap structure is provided between the first half arch ring and the second half arch ring; S3. Remove the first column near the opening of the mining access and the portion of the first arch ring below the rough section of the mining access, and mine the mining access.

2. The method for opening the first mining layer return mining route in the extremely broken ore rock route filling mining method according to claim 1 is characterized in that: The height of the rectangular hole is 8-12 cm higher than the height of the second threaded nut overlap structure; the length of the rectangular hole is 1-2 cm larger than the length of the reinforcing steel cross section, and the width of the rectangular hole is 1-2 cm larger than the width of the reinforcing steel cross section.

3. The method for opening the first mining layer return mining route in the extremely broken ore rock route filling mining method according to claim 1 is characterized in that: The distance between adjacent first steel arches is 0.8-1.2 m.

4. The method for opening the first mining layer return mining route in the extremely broken ore rock route filling mining method according to claim 1 is characterized in that: The mining of the to-be-mined access road in step S3 is specifically as follows: first, advance round steel anchor rods are constructed in the to-be-mined access road, and then mining and supporting are performed simultaneously; the support includes spraying concrete once, constructing the cement mortar anchor rods, laying the metal mesh, laying the steel belts, laying the second steel arch frame, and spraying concrete twice in the to-be-mined access road.

5. The method for opening the first mining layer return mining route in the extremely broken ore route filling mining method according to claim 4 is characterized in that: The diameter of the advanced round steel anchor rod is 30-35mm, the length is 3.0-3.5m, the circumferential spacing is 250-350mm, and the external insertion angle is 3°-5°; the thickness of the one-time shotcrete is 25-35mm, and the strength is C15; the cement mortar anchor rod is arranged perpendicular to the wall of the access road to be mined, and the diameter of the cement mortar anchor rod is 15-25mm, the length is 1.8-2.2m, and the mesh size is (0.8-1.2)m. ×(0.8-1.2)m; the mesh size of the metal mesh is (80-120)mm×(80-120)mm, and the size is (1.8-2.2)m×(0.8-1.2)m; the steel strip is a W-shaped steel strip with a length of 2.0-2.5m, a width of 200-250mm, and a thickness of 4-6mm. The spacing between adjacent steel strips is 0.8-1.2m; the thickness of the secondary sprayed concrete is 25-35mm.

6. The method for opening the first mining layer return mining route in the extremely broken ore route filling mining method according to claim 1 is characterized in that: In step S1, the outer diameter of the advance grouting anchor rod is 30-35mm, the wall thickness is 5-7mm, the length is 3.0-3.5m, the circumferential spacing is 250-350mm, and the external insertion angle is 3°-5°; the thickness of the primary sprayed concrete is 25-35mm, and the strength is C15; the cement mortar anchor rod is arranged perpendicular to the wall of the layered transport tunnel, the diameter of the cement mortar anchor rod is 15-25mm, the length is 1.8-2.2m, and the mesh size is (0.8-1.2)m×(0.8-1.2)m; the mesh size of the metal mesh is (80-120)mm×(80-120)mm, and the size is (1.8-2.2)m×(0.8-1.2)m; the spacing between adjacent steel strips is 0.8-1.2m; the thickness of the secondary sprayed concrete is 25-35mm.

7. The method for opening the first mining layer return mining route in the extremely broken ore route filling mining method according to claim 4 is characterized in that: The cement mortar anchor rod is provided with a tray at one end close to the layered transport tunnel or the access road to be mined.

8. The method for opening the first mining layer return mining route in the extremely broken ore route filling mining method according to claim 1 is characterized in that: The gross cross-sectional dimensions of the layered transport tunnel are 4.6m×3.9m, and the net cross-sectional dimensions after support are 4×3.6m; the gross cross-sectional dimensions of the access road to be mined are 3.8m×3.3m, and the net cross-sectional dimensions after support are 3.2×3.0m.

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