False bottom pre-support device and its construction method for downward approach filling process

Abstract

This application provides a false bottom pre-support device and its construction method for the downward approach filling process, belonging to the field of mining technology. The false bottom pre-support device includes a crushed ore cushion layer, several inflatable airbags arranged in an array, a steel mesh, and several expandable conical anchors. Each expandable conical anchor includes a conical rod body, several protrusions on the outer peripheral wall of the conical rod body, turnbuckles inside the conical rod body, and lifting bars and sliders connected to the upper and lower pull rings of the turnbuckles, respectively. The bottom end of the conical rod body is welded to the intersection of the main and secondary reinforcement bars of the steel mesh. The conical rod body is a hollow cylindrical structure, narrow at the top and wide at the bottom. When the entire false bottom shifts downwards, the lifting bars pull the slider upwards within the conical rod body. The resistance experienced by the slider increases, and the conical rod body is compressed by the slider, causing its wall to gradually widen, thus enhancing the anchoring force of the expandable conical anchor and the suspension force on the entire false bottom.

Description

Technical Field

[0001] This application relates to the field of mining technology, specifically to a false bottom pre-support device and its construction method for the downward approach filling process. Background Technology

[0002] As the development of metallic mineral resources extends to deeper areas, deep mining projects face multiple challenges, including high ground stress and complex geological structures. The construction of a safety control system has become a key technological bottleneck restricting the sustainable development of mines. Downward-entry backfilling mining, with its synergistic mechanism of "disturbance control-backfilling support," has demonstrated significant advantages in maintaining the stability of the surrounding rock in the stope and has now become the mainstream technology for deep ore body mining. In this technological system, the false bottom structure, as the core bearing unit supporting the load of the backfill and ensuring layered continuous mining, directly determines the level of stope instability risk and the efficiency of the mining cycle.

[0003] Current engineering practices mostly employ passive support systems based on the suspension principle, which use a single-layer steel mesh or anchor truss as the main load-bearing framework, and achieve structural suspension by anchoring the ends to the sides of the stope or the upper and lower walls of the ore body. This type of traditional false bottom has risks such as insufficient structural mechanical properties, weak interface coupling effects, and failure of boundary constraints.

[0004] To address the aforementioned problems, it is urgent to construct a new hoisting system architecture with stress-adaptive characteristics, improve the traditional false bottom laying structure, increase the filling and roof connection rate, and establish a real-time monitoring system for the false bottom that includes multi-parameter sensors. This will enable dynamic perception and instability warning of the deformation field and stress field of the false bottom structure, ensuring the safety and production efficiency of the downward filling mining area. Summary of the Invention

[0005] In view of the technical problems existing in the background art, this application provides a false bottom pre-support device and its construction method for the downward approach filling process. This false bottom pre-support device for the downward approach filling process is constructed by setting a conical rod body as a hollow cylindrical structure that is narrower at the top and wider at the bottom, with several protrusions on its outer peripheral wall; a turnbuckle with an integrated tension sensor is installed inside; the upper pull ring of the turnbuckle is connected to a lifting rod, and the lower pull ring of the turnbuckle is connected to a slider. The bottom end of the conical rod body is welded to the intersection of the main and secondary reinforcement bars; the upper end of the lifting rod is connected to the bottom of the top slab support or the upper false bottom; when the entire false bottom moves downward, the lifting rod pulls the slider upward within the conical rod body. Due to the conical rod body's narrower-than-wider structure, the resistance experienced by the slider increases, and the conical rod body is compressed by the slider, causing its tube wall to gradually widen, thus enhancing the anchoring force of the expansion conical anchor bolt and the suspension force on the entire false bottom.

[0006] In a first aspect, embodiments of this application provide a false bottom pre-support device for a downward approach filling process, comprising a crushed ore cushion layer disposed on the bottom slab of the approach stope, a plurality of inflatable airbags arranged in an array on the crushed ore cushion layer, a steel mesh, and a plurality of expandable conical anchor bolts; the expandable conical anchor bolt comprises a conical rod body, a plurality of protrusions disposed on the outer peripheral wall of the conical rod body, a turnbuckle disposed within the conical rod body, and lifting bars and sliders respectively connected to the upper and lower pull rings of the turnbuckle; the steel mesh comprises a plurality of mutually perpendicular main bars and The secondary reinforcement has a clearance space provided on the steel mesh for the inflatable airbag to pass through; the bottom end of the conical rod is welded to the intersection of the main reinforcement and the secondary reinforcement; the upper end of the lifting rod is connected to the bottom of the top slab support or the upper false bottom; the conical rod is a hollow cylindrical structure that is narrow at the top and wide at the bottom. When the entire false bottom moves downward, the lifting rod pulls the slider to move upward within the conical rod. The resistance on the slider increases, and the conical rod is squeezed by the slider, causing its tube wall to gradually widen, thereby enhancing the anchoring force of the expansion conical anchor and the suspension force on the entire false bottom.

[0007] In some embodiments, the expansion tapered anchor rod further includes a collar connecting the tapered rod body to the reinforcing mesh and a first pull ring connected to the bottom of the collar; the inner wall of the collar is welded to the intersection of the main reinforcement and the secondary reinforcement; a pressure sensor is provided inside the collar.

[0008] In some embodiments, the mesh size of the expansion tapered anchor bolt is 1000mm x 1500mm, that is, the spacing between adjacent expansion tapered anchor bolts along the length of the access road is 1m, and the spacing along the width of the access road is 1.5m.

[0009] In some embodiments, a plurality of the protrusions are evenly distributed on the outer peripheral wall of the tapered rod.

[0010] In some embodiments, the protrusion is provided with an inclined surface that slopes downward to the right from the outer peripheral wall of the tapered rod.

[0011] In some embodiments, the inflatable airbag is a cubic inflatable airbag with dimensions of 1.5m x 1.5m x 1.5m; the distance between adjacent inflatable airbags is 35m.

[0012] In some embodiments, a pull wire sensor is provided below the main rib or the secondary rib.

[0013] In some embodiments, a tension sensor is provided on the turnbuckle.

[0014] In some embodiments, the pressure sensor has an accuracy of 1 kN; the pull wire sensor has an accuracy of 1 mm; and the tension sensor has an accuracy of 0.1 kN.

[0015] Secondly, embodiments of this application provide a construction method for a false bottom pre-support device for the downward approach filling method, comprising the following steps:

[0016] S1. When the mining area is fully mined, a crushed ore cushion layer is laid on the bottom plate. The thickness of the crushed ore cushion layer is not less than 20cm, and geotextile is laid on the crushed ore cushion layer.

[0017] S2, place cubic inflatable airbags at a distance of 9.5-10.5m from the working face, and arrange one every 35m along the mining direction. The size of the cubic inflatable airbag is 1.5m x 1.5m x 1.5m.

[0018] S3, place wooden blocks on the geotextile, construct main and secondary reinforcement bars on the wooden blocks, and weld pull wire sensors under the main or secondary reinforcement bars.

[0019] S4. At the intersection of the main reinforcement and the secondary reinforcement, an expansion conical anchor rod is installed every 1000mm x 1500mm. The expansion conical anchor rod includes a conical rod body, several protrusions on the outer peripheral wall of the conical rod body, a turnbuckle inside the conical rod body, and a lifting rod and a slider connected to the upper and lower pull rings of the turnbuckle respectively. The conical rod body is a hollow cylindrical structure that is narrow at the top and wide at the bottom. The lower end of the expansion conical anchor rod is welded to the main reinforcement and the secondary reinforcement through a collar, and its top end is connected to the support of the top slab or the bottom of the upper false bottom through a lifting rod. Then, the turnbuckle inside the conical rod body is adjusted so that the tension sensor on the turnbuckle detects a preload of 1KN.

[0020] S5, carry out the false bottom and mining area filling work.

[0021] The beneficial effects of this invention are:

[0022] The false bottom pre-support device for the downward-approach filling process provided by this invention firstly constructs a three-dimensional anchoring system using expandable conical anchor rods with protruding portions ("barbs"). The synergistic effect of the conical rod and the "barbs" significantly enhances the overall mechanical performance of the false bottom structure. The radial constraint force generated by the "barbs" embedded in the filling material and the pre-tightening force of the turnbuckles form a composite anchoring effect, increasing the structural bearing capacity by more than 30%, effectively solving the problem of weak interface coupling in traditional false bottoms. Secondly, this invention, through a pre-embedded inflatable airbag system and the filling cavity formation mechanism, not only achieves precise connection of the lower filling pipeline to the top but also reduces material costs through the recyclable design of the airbags.

[0023] Third, this invention constructs a multi-dimensional monitoring system. The integrated tension sensor (inside the turnbuckle) and the pull wire sensor provide real-time feedback on the stress state of the anchor rod and the deformation of the false bottom, making the structural safety status visible. The monitoring accuracy reaches the 0.1mm level, and it can provide early warning of instability risks 12-24 hours in advance.

[0024] Furthermore, this invention has designed the distribution spacing of the expandable conical anchor bolts and the arrangement spacing of the inflatable airbags, realizing a modular design of the anchor bolt assembly and improving construction efficiency by 40%. Moreover, the layered lifting bar connection system (the lower layer of expandable conical anchor bolts is connected to the upper layer of expandable conical anchor bolts via lifting bars) in this application forms a continuous force transmission path, overcoming the technical bottleneck of traditional false bottom layered constraint failure. The overall technical solution, while ensuring the stability of the filling body, achieves a system integration innovation of support-monitoring-filling processes, providing a reliable guarantee for the safe and efficient mining of deep ore bodies.

[0025] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0027] Figure 1 This is a schematic diagram of the expansion cone anchor bolt in this application;

[0028] Figure 2 This is a top view of the arrangement of the false bottom steel mesh in the embodiments of this application;

[0029] Figure 3 This is a schematic diagram of the structure of the false bottom pre-support device used in the downward approach filling process in the embodiments of this application;

[0030] Figure 4 This is a construction schematic diagram of the false bottom pre-support device used in the downward approach filling process in the embodiments of this application. Detailed Implementation

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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).

[0037] 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.

[0038] 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.

[0039] In existing technologies, the down-pass backfilling mining process suffers from problems such as insufficient structural mechanical properties, weak interface coupling effects, and failure of boundary constraints.

[0040] Please see Figures 1 to 3 As shown, to solve the above problems, this application provides a false bottom pre-support device for the downward approach filling process, including a crushed ore cushion layer 12 set on the bottom plate of the approach stope, a plurality of inflatable airbags 17 arranged in an array on the crushed ore cushion layer, a steel mesh set above the crushed ore cushion layer 12, and a plurality of expandable conical anchor bolts 20. The expandable conical anchor bolt 20 includes a conical rod body 2, a plurality of protrusions 4 ("barbs") set on the outer peripheral wall of the conical rod body 2, a turnbuckle 3 set inside the conical rod body 2, and lifting bars 1 and sliders 5 respectively connected to the upper and lower pull rings of the turnbuckle 3. In this embodiment, the slider 5 is a uniform cylinder. A tension sensor is set inside the turnbuckle 3, with an accuracy of 0.1KN, for detecting the preload of the turnbuckle. In this embodiment, when installing the expansion tapered anchor bolt 20, the turnbuckle 3 inside the tapered rod body 2 is adjusted so that the tension sensor on the turnbuckle 3 detects a preload of 1KN, thereby putting the false bottom pre-support device under stress. By applying preload to the turnbuckle 3 during initial installation, the overall load-bearing capacity and instability risk warning sensitivity of the device are improved.

[0041] The reinforcing mesh includes several main bars 6 and secondary bars 7 arranged perpendicularly to each other, with clearance space 18 provided for the inflatable airbag 17 to pass through. The bottom end of the conical rod 2 is welded to the intersection of the main bars 6 and secondary bars 7; the upper end of the lifting bar 1 is connected to the bottom of the top slab support or the upper false bottom. The conical rod 2 is a hollow cylindrical structure that is narrow at the top and wide at the bottom. With this configuration, when the entire false bottom moves downward, the lifting bar 1 pulls the slider 5 to move upward within the conical rod 2. Due to the design of the conical rod 2 being narrow at the top and wide at the bottom, the resistance experienced by the slider 5 increases, and the conical rod 2 is squeezed by the slider 5, causing its tube wall to gradually widen, further enhancing the anchoring force of the anchor rod and the suspension force on the entire false bottom.

[0042] Furthermore, the expansion conical anchor also includes a collar 8 connecting the conical rod 2 to the reinforcing mesh. The inner wall of the collar 8 is welded to the intersection of the main reinforcement 6 and the secondary reinforcement 7. The conical rod 2 is welded to the collar 8 and connected to the main reinforcement 6 and the secondary reinforcement 7. A stress sensor is installed inside the collar 8 to measure stress changes in the vertical direction. When the entire false bottom undergoes downward displacement, the displacement is monitored, enabling visualization of the structural safety status.

[0043] The bottom of the collar 8 is connected to the first pull ring 9, and the suspension rod of the next layer of false bottom can be connected here to realize the formation of a continuous force transmission path through the layered suspension rod connection system, which solves the technical problem of failure of traditional false bottom layered constraint.

[0044] In this embodiment, the mesh size of the expansion tapered anchor bolt 20 is 1000mm x 1500mm, that is, the spacing between adjacent expansion tapered anchor bolts 20 along the length of the access road is 1m, and the spacing along the width of the access road is 1.5m.

[0045] Several protrusions 4 are evenly distributed on the outer peripheral wall of the conical rod 2. The protrusions 4 are provided with an inclined surface that slopes downward to the right from the outer peripheral wall of the conical rod 2.

[0046] The inflatable airbag is a cube-shaped inflatable airbag with dimensions of 1.5m x 1.5m x 1.5m; the distance between adjacent inflatable airbags is 35m.

[0047] The false bottom pre-support device used for the downward approach filling process is also equipped with a wire sensor 10. Depending on the strain area to be measured, the wire sensor 10 is welded to the bottom of the main rib 6 or the secondary rib 7 to monitor the strain of the false bottom.

[0048] The stress sensor has an accuracy of 1 kN; the wire sensor has an accuracy of 1 mm.

[0049] This false bottom pre-support device for the downward approach filling process can monitor the stress and strain of the false bottom structure through stress sensors and wire sensors 10 inside the collar 8. Specifically, the two sensors can be connected to the industrial ring network underground in the mine via data cables to achieve real-time data transmission. If real-time data transmission is not required, the data cable interface connecting the two sensors can be placed near the cubic inflatable airbag 17. When the lower approach mining exposes the filling pit 16 formed by the upper false bottom, the data cable interface can be exposed for data collection and analysis. By collecting the stress and strain data of the false bottom, the morphology of the false bottom and the risk of collapse can be monitored.

[0050] The thickness of the crushed ore cushion layer 12 is greater than or equal to 20cm.

[0051] Please see Figure 4As shown, this application also provides a construction method for a false bottom pre-support device for the downward approach filling method, including the following steps:

[0052] S1. When the mining area is fully mined, a crushed ore cushion layer 12 is laid on the bottom plate. The thickness of the crushed ore cushion layer 12 is not less than 20cm, and geotextile is laid on the crushed ore cushion layer 12.

[0053] S2, place 17 cubic inflatable airbags at a distance of 9.5-10.5m from the working face, and arrange one every 35m along the strike of the mining area. The size of the cubic inflatable airbag is 1.5m x 1.5m x 1.5m.

[0054] S3, place several wooden blocks 11 at equal intervals on the geotextile, construct main reinforcement 6 and secondary reinforcement 7 on the wooden blocks, and weld the pull wire sensor 10 under the main reinforcement 6 or secondary reinforcement 7.

[0055] S4. At the intersection of the main reinforcement 6 and the secondary reinforcement 7, an expansion tapered anchor rod 20 is installed every 1000mm x 1500mm. The lower end of the expansion tapered anchor rod 20 is welded to the main and secondary reinforcement through the collar 8, and its top end is connected to the support of the top plate (when this layer is the first mining layer) or the first pull ring 9 at the bottom of the upper false bottom (when this layer is not the first mining layer) through the lifting bar 1. After the connection is completed, the turnbuckle 3 inside the tapered rod body 2 is adjusted so that the tension sensor on the turnbuckle 3 detects a preload of 1KN.

[0056] S5, carry out the false bottom and mining area filling work.

[0057] During the construction of the lower mining area, the presence of the previously placed cubic inflatable airbags 17 creates a filling cavity 16 in the roof. Suspending the end of the filling pipe 15 in the filling cavity 16 can effectively solve the filling and roof connection problem of this layer and significantly improve the filling and roof connection rate.

[0058] By applying pre-tightening force to the turnbuckle 3 during initial installation, the overall load-bearing capacity of the device and the sensitivity of instability risk warning are improved.

[0059] 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 false bottom pre-support device for the downward approach filling method, characterized in that, The system includes a crushed ore cushion layer installed on the bottom plate of the access mining area, several inflatable airbags arranged in an array on the crushed ore cushion layer, a steel mesh, and several inflatable conical anchor bolts. Each inflatable conical anchor bolt includes a conical rod body, several protrusions on the outer peripheral wall of the conical rod body, a turnbuckle installed inside the conical rod body, a lifting bar connected to the upper pull ring of the turnbuckle, and a slider connected to the lower pull ring of the turnbuckle. The steel mesh includes several main and secondary bars arranged perpendicularly to each other, and the steel mesh is provided with supports for the... The conical rod has a clearance space through which an inflatable airbag can pass; the bottom end of the conical rod is welded to the intersection of the main and secondary reinforcing bars; the upper end of the lifting bar is connected to the bottom of the top plate support or the upper false bottom; the conical rod is a hollow cylindrical structure that is narrow at the top and wide at the bottom. When the entire false bottom moves downward, the lifting bar pulls the slider to move upward within the conical rod. The resistance experienced by the slider increases, and the conical rod is squeezed by the slider, causing its tube wall to gradually widen, thereby enhancing the anchoring force of the expansion conical anchor and the suspension force on the entire false bottom.

2. The false bottom pre-support device for the downward approach filling process according to claim 1, characterized in that, The expansion conical anchor also includes a collar connecting the conical rod body to the reinforcing mesh and a first pull ring connected to the bottom of the collar; the inner wall of the collar is welded to the intersection of the main reinforcement and the secondary reinforcement; a pressure sensor is installed inside the collar.

3. The false bottom pre-support device for the downward approach filling process according to claim 1, characterized in that, The spacing between adjacent expansion cone anchors is 1m along the length of the access road and 1.5m along the width of the access road.

4. The false bottom pre-support device for the downward approach filling process according to claim 1, characterized in that, Several of the aforementioned protrusions are evenly distributed on the outer peripheral wall of the conical rod.

5. The false bottom pre-support device for the downward approach filling method according to claim 1, characterized in that, The protruding part is provided with an inclined surface that slopes downward to the right from the outer peripheral wall of the tapered rod.

6. The false bottom pre-support device for the downward approach filling process according to claim 1, characterized in that, The inflatable airbag is a cube-shaped inflatable airbag with dimensions of 1.5m x 1.5m x 1.5m; the distance between adjacent inflatable airbags is 35m.

7. The false bottom pre-support device for the downward approach filling process according to claim 2, characterized in that, A pull wire sensor is installed below the main reinforcement or the secondary reinforcement.

8. The false bottom pre-support device for the downward approach filling process according to claim 7, characterized in that, A tension sensor is installed on the turnbuckle.

9. The false bottom pre-support device for the downward approach filling process according to claim 8, characterized in that, The pressure sensor has an accuracy of 1 kN; the pull wire sensor has an accuracy of 1 mm; and the tension sensor has an accuracy of 0.1 kN.

10. A construction method for a false bottom pre-support device used in the downward approach filling process, characterized in that, Includes the following steps: S1. When the mining area is fully mined, a crushed ore cushion layer is laid on the bottom plate. The thickness of the crushed ore cushion layer is not less than 20cm, and geotextile is laid on the crushed ore cushion layer. S2, place cubic inflatable airbags at a distance of 9.5-10.5m from the working face, and arrange one every 35m along the mining direction. The size of the cubic inflatable airbag is 1.5m x 1.5m x 1.5m. S3, place wooden blocks on the geotextile, construct main and secondary reinforcement bars on the wooden blocks, and weld pull wire sensors under the main or secondary reinforcement bars. S4. At the intersection of the main reinforcement and the secondary reinforcement, an expansion conical anchor rod is installed every 1000mm x 1500mm. The expansion conical anchor rod includes a conical rod body, several protrusions on the outer peripheral wall of the conical rod body, a turnbuckle inside the conical rod body, a lifting rod connected to the upper end of the turnbuckle, and a slider connected to the lower end of the turnbuckle. The conical rod body is a hollow cylindrical structure that is narrow at the top and wide at the bottom. The lower end of the expansion conical anchor rod is welded to the main reinforcement and the secondary reinforcement through a collar, and its top end is connected to the support of the top slab or the bottom of the upper false bottom through a lifting rod. Then, the turnbuckle inside the conical rod body is adjusted so that the tension sensor on the turnbuckle detects a preload of 1KN. S5, carry out the false bottom and mining area filling work.

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