Metal mine lateral constant-rigidity pillar filling body mechanical test device and method

Abstract

The invention provides a mechanical test device and method for a lateral constant-rigidity pillar filling body of a metal mine, and relates to the technical field of mechanical simulation tests of the metal mine. According to the invention, the accurate mechanical simulation of the pillar-filling body combination under the constant lateral stiffness boundary condition is realized, and the authenticity and reliability of the test are greatly improved. An inner bearing plate and an outer bearing plate which are connected through an elastic piece (such as a spring) are arranged on the two sides of an ore pillar-filling body test piece, and a boundary condition capable of providing constant lateral rigidity is constructed. By means of the design, the mechanical behavior that the restraining effect of surrounding rock (jambs) on a filling body can be correspondingly adjusted along with deformation of the jambs in an actual mine can be dynamically simulated, the defect that a traditional rigid boundary loading mode cannot reflect dynamic changes of lateral pressure is thoroughly overcome, and the test result is closer to engineering practice. According to the invention, the integrality and integration test of the pillar-filling body-surrounding rock system is realized, and the research perspective is more scientific and systematic.

Description

Technical Field

[0001] This invention relates to the field of mechanical simulation testing technology for metal ores, specifically to a mechanical testing device and method for a lateral constant stiffness pillar filling body in metal ores. Background Technology

[0002] Cemented backfill mining has become an important technology in metal mining due to its significant advantages in environmental protection and resource recovery efficiency. However, its further widespread application and optimization are still limited by insufficient understanding of the complex interaction mechanisms between pillars, backfill, and surrounding rock (pillars around the backfill). In actual mine production, especially in two-stage mining processes, pillars and backfill are arranged alternately. The consolidated backfill is in close contact with adjacent pillars, forming a load-bearing structure. Due to factors such as the water content of the backfill slurry, consolidation shrinkage characteristics, and unevenness of the stope roof, the backfill and roof are often not in complete contact, causing the load of the overlying strata to be mainly borne by the pillars. In this case, the main function of the backfill is to limit the lateral deformation of the pillars, thereby improving their stress state.

[0003] In this mechanical process, the infill material is constrained by pillars on both sides of the stope, generating lateral pressure. It is worth noting that in metal mines, the strength of the infill material is typically much lower than that of the pillars. Existing experimental setups for simulating this condition often employ a passive loading method with rigid displacement constraints. This method fails to reflect the core characteristic of actual engineering: the lateral pressure dynamically adjusts with pillar deformation to maintain a constant lateral stiffness boundary condition. Therefore, traditional rigid boundary conditions are insufficient to realistically simulate the constraint effect of the surrounding rock on the infill material, leading to discrepancies between experimental results and actual engineering conditions.

[0004] Furthermore, current research methods often have limitations, tending to examine pillars, infill bodies, and surrounding rocks as isolated components rather than analyzing them as an interconnected and synergistic whole system. This one-sided research perspective makes it difficult to reveal the complex mechanical behavior of the "pillar-infill-surrounding rock" system in actual geological environments. Summary of the Invention

[0005] The purpose of this invention is to provide a mechanical testing device and method for a lateral constant stiffness ore pillar filling body in a metal mine, so as to more realistically simulate the constant lateral stiffness boundary conditions and conduct systematic mechanical testing on the "ore pillar-filling body-surrounding rock".

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore mine, comprising: Base; A vertical reaction frame is mounted on the base and arranged vertically. A crossbeam is installed at the upper end of the vertical reaction frame; The loading unit is mounted on the crossbeam, and the loading head of the loading unit is arranged vertically. The upper loading plate is located below the loading head. A vertical pressure sensor is connected between the upper loading plate and the loading head, and a vertical displacement sensor is installed on the upper loading plate. A lower loading plate is set on the base and located below the upper loading plate; a pillar-filling body specimen is placed between the lower loading plate and the upper loading plate. External bearing plates are installed on the base and located on opposite sides of the pillar-filling body specimen; The inner bearing plate is attached to the opposite side of the pillar-filling body specimen. A lateral displacement sensor is installed on the inner bearing plate. An elastic element with a set stiffness is connected between the inner bearing plate and the outer bearing plate. A lateral pressure sensor is connected between the elastic element and the inner or outer bearing plate.

[0007] Preferably, it also includes a control unit, which is signal-connected to the control terminal of the loading unit, the vertical pressure sensor, the vertical displacement sensor, the lateral displacement sensor, and the lateral pressure sensor.

[0008] Preferably, an upper clamping groove is provided on one side of the upper loading plate that is attached to the ore pillar-filling body specimen, and a lower clamping groove is provided on one side of the lower loading plate that is attached to the ore pillar-filling body specimen. The upper and lower ends of the ore pillar-filling body specimen are located in the upper clamping groove and the lower clamping groove, respectively.

[0009] Preferably, the elastic element is a spring.

[0010] Preferably, the loading unit is configured as a hydraulic cylinder, and the loading head of the loading unit is configured as the telescopic end of the hydraulic cylinder.

[0011] Preferably, the pillar-filling body specimen includes a pillar simulator and a filling body simulator. The pillar simulator is prepared by sampling the pillar on site. The pillar simulator is placed in the middle of the mold and the filling slurry is injected into the mold to obtain the filling body simulator. After demolding, the pillar-filling body specimen is obtained.

[0012] Preferably, a slide rail is arranged on the base along the horizontal direction, and a slider is slidably fitted on the slide rail, with the lower end of the outer pressure plate disposed on the slider; A lead screw is rotatably connected to the base, and a lead screw nut is fitted onto the lead screw. The lead screw nut is located on the slider.

[0013] Preferably, the two ends of the lead screw are rotatably connected to the base via bearings.

[0014] Preferably, the outer end of the lead screw is provided with a rotating head, and an external force is applied to the rotating head to drive the lead screw to rotate.

[0015] A mechanical testing method for lateral constant stiffness pillar filling in metal mines, utilizing the aforementioned mechanical testing device for lateral constant stiffness pillar filling in metal mines, the method comprising the following steps: S1. Obtain the stiffness K of the pillars surrounding the backfill body in the area to be cemented and backfilled on site. w ; S2. Place the prepared pillar-filling body specimen between the lower loading plate and the upper loading plate, and attach the inner bearing plate to the opposite sides of the pillar-filling body specimen. The stiffness is K. w An elastic element connects the inner and outer bearing plates, adjusting the distance between them. This distance is monitored by a lateral pressure sensor, and the force is controlled by a stiffness of K. w The elastic element applies initial confining pressure stress to the pillar-filling specimen. ; S3. Axial pressure is applied to the pillar-filling body specimen through the loading head of the loading unit. The axial pressure stress is monitored by a vertical pressure sensor, and the axial loading displacement is monitored by a vertical displacement sensor. During the application of axial compression to the pillar-filling body specimen, the side of the specimen deforms. The lateral displacement of the inner bearing plate is monitored by a lateral displacement sensor, and the lateral displacement of the inner bearing plate represents the lateral deformation of the pillar-filling body specimen. The confining pressure stress is monitored in real time by a lateral pressure sensor. .

[0016] The beneficial technical effects of this invention are: 1. This invention achieves accurate mechanical simulation of the pillar-filling body assembly under constant lateral stiffness boundary conditions, greatly improving the realism and reliability of the experiment. By setting inner and outer bearing plates connected by elastic elements (such as springs) on both sides of the pillar-filling body specimen, a boundary condition that can provide constant lateral stiffness is constructed. This design can dynamically simulate the mechanical behavior of the constraint effect of the surrounding rock (pillar) on the filling body in actual mines, which adjusts accordingly with the deformation of the pillar itself. This completely overcomes the defect of traditional rigid boundary loading methods that cannot reflect the dynamic changes of lateral pressure, making the test results closer to engineering reality.

[0017] 2. This invention enables holistic and integrated testing of the "pillar-filling-surrounding rock" system, providing a more scientific and systematic research perspective. This device and method do not test the pillar or filling material in isolation, but rather prepare them as a pillar-filling material specimen for testing as a single load-bearing structure. This accurately reflects the interaction, load transfer, and deformation coordination mechanisms between the two during the stress process, providing a crucial experimental means to deeply reveal the overall mechanical behavior of this complex "pillar-filling-surrounding rock" system.

[0018] 3. The experimental method of this invention forms a complete and standardized testing procedure, from obtaining on-site stiffness parameters to specimen preparation and installation, and then to applying lateral constant stiffness boundary conditions and axial loading. This method not only simplifies the experimental procedure and reduces research costs, but also can adapt to and simulate various different filling schemes and surrounding rock conditions. It provides direct and reliable experimental basis for the study of filling support mechanisms, filling ratio optimization, and mining engineering design, and has significant theoretical and engineering application value. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the mechanical testing device for a lateral constant stiffness pillar filling body in a metal mine, according to an embodiment of the present invention. Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle; Figure 3 This is a front view of a pillar-filling specimen according to an embodiment of the present invention; Figure 4 This is a top view of a pillar-filling specimen according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the lateral deformation of a pillar-filling body specimen according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Certain embodiments of the invention will be described more fully below with reference to the accompanying drawings, and some, but not all, of these embodiments will be shown. In fact, various embodiments of the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable the invention to meet applicable legal requirements.

[0021] In the description of this invention, it should be noted that the terms "inner," "outer," "upper," "lower," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not 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 this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In this embodiment of the invention, a mechanical testing device and method for a lateral constant stiffness pillar filling body in a metal ore is provided. Please refer to [reference needed]. Figures 1 to 5 As shown.

[0023] A mechanical testing device for a lateral constant stiffness pillar filling body in a metal mine includes a base 1, a vertical reaction frame 2, a crossbeam 3, a loading unit 4, an upper loading plate 51, a lower loading plate 52, an outer pressure plate 61, and an inner pressure plate 62.

[0024] The lower end of the vertical reaction frame 2 is assembled on the base 1, and the vertical reaction frame 2 is arranged vertically, with the crossbeam 3 located at the upper end of the vertical reaction frame 2.

[0025] The loading unit 4 is mounted on the crossbeam 3, and the loading head of the loading unit 4 is arranged vertically. The loading unit 4 is configured as a hydraulic cylinder, and the loading head of the loading unit 4 is configured as the telescopic end of the hydraulic cylinder.

[0026] The upper loading plate 51 is located below the loading head. A vertical pressure sensor 71 is connected between the upper loading plate 51 and the loading head. A vertical displacement sensor 72 is installed on the upper loading plate 51.

[0027] The lower loading plate 52 is disposed on the base 1 and located below the upper loading plate 51. The pillar-filling body specimen 8 is placed between the lower loading plate 52 and the upper loading plate 51.

[0028] The upper loading plate 51 has an upper clamping groove on one side of the ore pillar-filling specimen 8, and the lower loading plate 52 has a lower clamping groove on one side of the ore pillar-filling specimen 8. The upper and lower ends of the ore pillar-filling specimen 8 are located in the upper and lower clamping grooves, respectively. The clamping grooves on the upper and lower loading plates ensure the centering and stability of the ore pillar-filling specimen 8 during the loading process and prevent eccentric loading.

[0029] The pillar-filling specimen 8 includes a pillar simulator 81 and a filling body simulator 82. A cylindrical pillar simulator 81 is prepared by sampling the pillar on site. The pillar simulator 81 is placed in the middle of the mold and filling slurry is injected into the mold to obtain the filling body simulator 82. After demolding, the pillar-filling specimen 8 is obtained.

[0030] The outer bearing plate 61 is set on the base 1 and is located on both sides opposite to the pillar-filling body specimen 8.

[0031] A slide rail 11 is arranged horizontally on the base 1, and a slider 12 is slidably fitted on the slide rail 11. The lower end of the outer pressure plate 61 is set on the slider 12. The two ends of the lead screw 13 are rotatably connected to the base 1 via bearings 14. A lead screw nut 15 is fitted on the lead screw 13 and is set on the slider 12. A rotating head 16 is set at the outer end of the lead screw 13. External force is applied to the rotating head 16 to drive the lead screw 13 to rotate.

[0032] An external force acts on the rotating head 16, causing the lead screw 13 to rotate. Through the engagement of the lead screw 13 and the lead nut 15, the slider 12 slides along the slide rail 11, thereby moving the outer bearing plate 61 closer to or further away from the inner bearing plate 62, thus adjusting the distance between the outer and inner bearing plates 61. By adjusting the distance between the outer and inner bearing plates 62, different sizes of pillar-filling body specimens 8 can be accommodated, as well as different specifications of elastic elements 63. The compression of the elastic element 63 can be adjusted to precisely apply the initial confining pressure stress. .

[0033] The inner bearing plate 62 is attached to the opposite sides of the pillar-filling body specimen 8. The front, rear, left, and right sides of the pillar-filling body specimen 8 are all attached to the inner bearing plate 62. A lateral displacement sensor 73 is installed on the inner bearing plate 62. An elastic element 63 with a set stiffness is connected between the inner bearing plate 62 and the outer bearing plate 61. The elastic element 63 is a spring. A lateral pressure sensor 74 is connected between the elastic element 63 and either the inner bearing plate 62 or the outer bearing plate 61.

[0034] The control unit is configured as a computer, and is connected via signal cables to the control terminal of the loading unit 4, the vertical pressure sensor 71, the vertical displacement sensor 72, the lateral displacement sensor 73, and the lateral pressure sensor 74. The control unit triggers the loading head of the loading unit 4 to apply axial pressure to the pillar-filling specimen 8. The control unit acquires the axial compressive stress in real time through the vertical pressure sensor 71, the axial loading displacement in real time through the vertical displacement sensor 72, the lateral displacement of the inner bearing plate 62 in real time through the lateral displacement sensor 73, and the confining pressure stress in real time through the lateral pressure sensor 74. .

[0035] A mechanical testing method for lateral constant stiffness pillar filling in metal mines, using the mechanical testing device for lateral constant stiffness pillar filling in metal mines described in this embodiment, includes the following steps: S1. Obtain the stiffness K of the pillars surrounding the backfill body in the area to be cemented and backfilled on site. w ; S2. Place the prepared pillar-filling specimen 8 between the lower loading plate 52 and the upper loading plate 51, and attach the inner bearing plate 62 to the opposite sides of the pillar-filling specimen 8. The stiffness is K. w The elastic element 63 is connected between the inner bearing plate 62 and the outer bearing plate 61, adjusting the distance between the outer bearing plate 61 and the inner bearing plate 62, and is monitored by the lateral pressure sensor 74, with a stiffness of K. w The elastic element 63 applies initial confining pressure stress to the pillar-filling specimen 8. ; Among them, the internal bearing plate is 62, and the stiffness is K. wThe elastic element 63 and the outer bearing plate 61 are used to simulate the pillar (surrounding rock) around the filling body.

[0036] S3. Axial pressure is applied to the pillar-filling body specimen 8 through the loading head of the loading unit 4 to simulate the roof pressure on the pillar-filling body. The axial pressure stress is monitored by the vertical pressure sensor 71 and the axial loading displacement is monitored by the vertical displacement sensor 72. During the application of axial compression to the pillar-filling specimen 8, the side of the pillar-filling specimen 8 deforms. The lateral displacement of the inner bearing plate 62 is monitored by the lateral displacement sensor 73, and the lateral displacement of the inner bearing plate 62 is the lateral deformation of the pillar-filling specimen 8. The confining pressure stress is monitored in real time by the lateral pressure sensor 74. .

[0037] Among them, the pillar-filling specimen 8 is subject to a boundary condition in which the lateral force gradually increases with the increase of its lateral deformation. This boundary condition is called the lateral constant stiffness boundary condition. Based on the lateral deformation of the pillar-filling specimen 8... and the stiffness K of the pillar (surrounding rock) surrounding the filling body w To calculate the stress exerted by the pillar (surrounding rock) on the pillar-filling specimen 8. The calculation formula is: The confining pressure stress is monitored in real time by the lateral pressure sensor 74. right Perform verification and validation.

[0038] The present invention has been described in detail with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the mechanical testing device and method for lateral constant stiffness pillar filling in metal mines according to the present invention. Of course, the specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore mine, characterized in that, include: Base; A vertical reaction frame is mounted on the base and arranged vertically. A crossbeam is installed at the upper end of the vertical reaction frame; The loading unit is mounted on the crossbeam, and the loading head of the loading unit is arranged vertically. The upper loading plate is located below the loading head. A vertical pressure sensor is connected between the upper loading plate and the loading head, and a vertical displacement sensor is installed on the upper loading plate. A lower loading plate is set on the base and located below the upper loading plate; a pillar-filling body specimen is placed between the lower loading plate and the upper loading plate. External bearing plates are installed on the base and located on opposite sides of the pillar-filling body specimen; The inner bearing plate is attached to the opposite side of the pillar-filling body specimen. A lateral displacement sensor is installed on the inner bearing plate. An elastic element with a set stiffness is connected between the inner bearing plate and the outer bearing plate. A lateral pressure sensor is connected between the elastic element and the inner or outer bearing plate.

2. The mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore according to claim 1, characterized in that: It also includes a control unit, which is connected to the control terminal of the loading unit, the vertical pressure sensor, the vertical displacement sensor, the lateral displacement sensor, and the lateral pressure sensor.

3. The mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore according to claim 1, characterized in that: An upper clamping groove is provided on one side of the upper loading plate that is attached to the ore pillar-filling body specimen, and a lower clamping groove is provided on the other side of the lower loading plate that is attached to the ore pillar-filling body specimen. The upper and lower ends of the ore pillar-filling body specimen are located in the upper clamping groove and the lower clamping groove, respectively.

4. The mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore according to claim 1, characterized in that: The elastic element is configured as a spring.

5. The mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore according to claim 1, characterized in that: The loading unit is configured as a hydraulic cylinder, and the loading head of the loading unit is configured as the telescopic end of the hydraulic cylinder.

6. The mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore according to claim 1, characterized in that: The pillar-filling body specimen includes a pillar simulator and a filling body simulator. A pillar simulator is prepared by sampling a pillar on site. The pillar simulator is placed in the middle of a mold and filling slurry is injected into the mold to prepare a filling body simulator. After demolding, the pillar-filling body specimen is obtained.

7. The mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore according to claim 1, characterized in that: The base is provided with a slide rail arranged horizontally, and a slider is slidably fitted on the slide rail. The lower end of the outer pressure plate is disposed on the slider. A lead screw is rotatably connected to the base, and a lead screw nut is fitted onto the lead screw. The lead screw nut is located on the slider.

8. The mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore according to claim 7, characterized in that: The two ends of the lead screw are rotatably connected to the base via bearings.

9. The mechanical testing device for a lateral constant stiffness pillar filling body in a metal ore according to claim 7, characterized in that: The outer end of the lead screw is provided with a rotating head, and external force is applied to the rotating head to drive the lead screw to rotate.

10. A method for mechanical testing of lateral constant stiffness pillar filling in a metal ore mine, using the mechanical testing apparatus for lateral constant stiffness pillar filling in a metal ore mine as described in any one of claims 1 to 9, characterized in that, The method includes the following steps: S1. Obtain the stiffness K of the pillars surrounding the backfill body in the cemented backfill area on site. w ; S2. Place the prepared pillar-filling body specimen between the lower loading plate and the upper loading plate, and attach the inner bearing plate to the opposite sides of the pillar-filling body specimen. The stiffness is K. w An elastic element connects the inner and outer bearing plates, adjusting the distance between them. This distance is monitored by a lateral pressure sensor, and the force is controlled by a stiffness of K. w The elastic element applies initial confining pressure stress to the pillar-filling specimen. ; S3. Axial pressure is applied to the pillar-filling body specimen through the loading head of the loading unit. The axial pressure stress is monitored by a vertical pressure sensor, and the axial loading displacement is monitored by a vertical displacement sensor. During the application of axial compression to the pillar-filling body specimen, the side of the specimen deforms. The lateral displacement of the inner bearing plate is monitored by a lateral displacement sensor, and the lateral displacement of the inner bearing plate represents the lateral deformation of the pillar-filling body specimen. The confining pressure stress is monitored in real time by a lateral pressure sensor. .

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