A solid filling material compression test device and method capable of simulating filling step distance and lateral pressure

Abstract

The embodiment of the present invention provides a solid filling material compression test device and method that can simulate the filling step and lateral pressure, and relates to the technical field of mechanical property testing of solid filling materials. The device includes: a model box, on the bottom plate, a first side plate, a second side plate, a third side plate and a fourth side plate are arranged around the bottom plate, the first side plate is opposite to the third side plate, and is used to simulate the upper and lower drifts of the coal mining working face, respectively, the second side plate is opposite to the fourth side plate, and is used to simulate the open eye coal wall, a pressure component is arranged on the fourth side plate, and under the push of the pressure component, the fourth side plate moves toward the second side plate, and a plurality of discharge plates arranged parallel to the fourth side plate are arranged on the top of the first side plate and the third side plate, and the discharge plate has a filling port for filling into the filling space. The experimental results obtained based on the experimental device and method can more accurately reflect the mechanical properties of solid filling materials in actual filling mining.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical property testing of solid filling materials, and in particular to a solid filling material compression test device and method capable of simulating filling step distance and lateral pressure. Background Art

[0002] Traditional large-scale caving mining has caused great losses to coal resources and caused great damage to the ecological environment of mining areas and surrounding areas. The main manifestations are: (i) Serious coal losses: Serious coal losses under buildings, water bodies, and railways, and there are also certain coal pillar losses between sections. (ii) Large amounts of solid waste discharged from mines: Coal mines generate a large amount of gangue solid waste when mining coal. The general treatment method is to directly discharge it to the surface to form a gangue mountain; the ground discharge of solid waste from mines will cause environmental pollution and harm, encroach on good farmland, and cause secondary disasters. (iii) Mining brings serious environmental damage: mainly manifested in serious damage to land resources, large-scale loss of groundwater, and surface collapse.

[0003] In view of the above problems caused by caving mining, the best solution is backfill mining. The most widely used backfill mining method with the most extensive material sources is solid backfill mining. In the solid backfill mining process, the mechanical properties of the solid backfill material play a key role in the backfill effect. At present, the mechanical property test of the backfill material is basically carried out by the side confined compression test, that is, a steel cylinder with a certain rigidity is used as a loading device, such as Figure 1 As shown; the electro-hydraulic servo press is then used to compress the solid filling material through the piston, test its stress-strain curve, and analyze the mechanical properties of the material. This device is easy to operate and can well reflect the mechanical properties of the solid filling material to a certain extent.

[0004] The inventors of this application discovered during the process of realizing the invention that the confined compression test currently carried out to study the mechanical properties of solid filling materials cannot realistically simulate the mechanical behavior (i.e., the actual stress state) exhibited by the filling materials during the actual filling process, resulting in that the existing confined compression test results cannot accurately reflect the mechanical properties of the solid filling materials in actual filling and mining. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a solid filling material compression test device and method that can more realistically simulate the actual stress state of the filling material in the actual filling process and can simulate the filling step and lateral pressure. The experimental results obtained based on the experimental device and method can more accurately reflect the mechanical properties of the solid filling material in actual filling and mining.

[0006] In a first aspect, an embodiment of the present invention provides a solid filling material compression test device capable of simulating filling step distance and lateral pressure, comprising: a model box, the model box comprising a bottom plate, a first side plate, a second side plate, a third side plate and a fourth side plate are arranged around the bottom plate, the space surrounded by the first side plate, the second side plate, the third side plate and the fourth side plate forms a filling space for simulating a goaf, the first side plate is opposite to the third side plate, and is respectively used to simulate the upper and lower drifts of a coal mining working face, the second side plate is opposite to the fourth side plate, the second side plate is used to simulate an open-eye coal wall, two ends of the fourth side plate are respectively movably connected to the first side plate and the third side plate, and can be moved in the direction of the line connecting the fourth side plate, a pressure component is arranged on the fourth side plate, and under the push of the pressure component, the fourth side plate moves toward the second side plate, so as to simulate the lateral compaction force exerted on the solid filling material by the compaction mechanism on the hydraulic support during the actual filling process;

[0007] A plurality of unloading plates arranged parallel to the fourth side plate are mounted on the top of the first side plate and the third side plate, and the unloading plates have filling ports for filling the filling space. The unloading plates are used to simulate the bottom-unloading conveyor suspended on the rear top beam of the hydraulic support during the actual filling process.

[0008] Optionally, a plurality of first groove portions are provided at equal intervals at the top end of the first side plate along the length direction, a plurality of second groove portions are provided at equal intervals at the top end of the third side plate along the length direction, and the first groove portions are arranged corresponding to the second groove portions, and one end of the unloading plate is arranged in the first groove portion, and the other end is arranged in the second groove portion.

[0009] Optionally, the first groove portion and the second groove portion are semicircular grooves, and both ends of the discharge plate have semicircular overlapping portions, and both ends of the discharge plate are overlapped in the semicircular grooves through the semicircular overlapping portions.

[0010] Optionally, the unloading plate is a sheet metal part made of a metal sheet and having an arc-shaped cross-section.

[0011] Optionally, the pressure-applying component is a jack.

[0012] In a second aspect, an embodiment of the present invention provides a solid filling material compression test method, which is implemented based on any solid filling material compression test device capable of simulating filling step and lateral pressure as described in the first aspect, and the method comprises the steps of:

[0013] S10, according to the horizontal distance between the hinge point of the tamping mechanism on the hydraulic support and the base of the hydraulic support and the center of the bottom unloading conveyor in the actual filling mining, adjust the distance from the fourth side plate to the center line of the filling port of the first unloading plate; wherein the first unloading plate is counted toward the fourth side plate with the second side plate as a reference;

[0014] S20, filling material into the filling space through the filling port on the first unloading plate to simulate a "mine-one-fill" filling mining mode;

[0015] S30, when the filler space is filled with material, the fourth side plate is pushed toward the second side plate by the pressure member to simulate the lateral compaction process of the compaction mechanism on the hydraulic support;

[0016] S40. After compaction is completed, the filling material is compressed by an electro-hydraulic servo press, and the volume change rate and strain-stress curve of the compressed filling material are monitored.

[0017] Optionally, the method also includes: changing the position of the filler during the experiment, filling the filler space with material from the filling port on the nth unloading plate to simulate the "mining n and filling one" filling mining mode; the n ≥ 1, and n is an integer; based on different filler positions, repeating steps S30 and S40 respectively, monitoring and obtaining the volume change rate and strain-stress curve of the compressed filler material after each change of the filler position, so as to simulate the mechanical influence of different filling step distances on the solid filling material during the actual filling process; analyzing the mechanical influence of different filling step distances on the solid filling material according to the volume change rate and strain-stress curve of the compressed filler material obtained each time.

[0018] Optionally, the method also includes: in each experiment, changing the thrust of the pressure component to simulate the compaction process of different lateral compaction forces; monitoring the volume change rate and strain-stress curve of the compressed filling material after each change of the thrust size to simulate the mechanical influence of different lateral compaction forces on the solid filling material during the actual filling process; and analyzing the mechanical influence of different lateral compaction forces on the solid filling material based on the volume change rate and strain-stress curve of the compressed filling material obtained each time.

[0019] Optionally, in each experiment, the thrust of the pressure-applying component and the position of the filler are changed, and the volume change rate and strain-stress curve of the compressed filler are monitored after each change of the thrust and the position of the filler, so as to simulate the mechanical influence of different lateral tamping forces and different filling step distances on the solid filling material in the actual filling process; based on the volume change rate and strain-stress curve of the compressed filler obtained each time, the mechanical influence of different lateral tamping forces and filling step distances on the solid filling material is analyzed.

[0020] Optionally, before step S10, the method further comprises: making the solid filling material compression test device capable of simulating the filling step distance and lateral pressure;

[0021] Specifically: according to the actual mining height of the coal mining face and the key parameters of the filling hydraulic support, a reasonable model similarity ratio is determined; the key parameters include the horizontal distance between the hinge point of the tamping mechanism on the hydraulic support and the base of the hydraulic support and the center of the bottom unloading conveyor; the model box size is determined based on the model similarity ratio; three high-strength thick steel plates of equal height are taken, namely the first side plate, the second side plate and the third side plate, which are fixedly connected to the bottom plate to form a box body with three fixed connections, which is used to simulate the three-sided closed goaf space in the actual coal mining face; wherein the first side plate and the third side plate are respectively connected to the second side plate at an angle of 90°, and the first side plate is opposite to the third side plate, the first side plate and the third side plate are respectively used to simulate the upper and lower drifts on the coal mining face, and the second side plate is used to simulate the open eye coal wall; in the box body, on the side opposite to the second side, a piece that can be moved along the second side is embedded The fourth side plate that moves in the direction of the connecting line of the side plates is used to simulate the compacting mechanism of the movable filling hydraulic support on the working face; the second side plate and the fourth side plate are high-strength steel plates of the same material and height; a jack is installed on the outer side of the fourth side plate to apply lateral pressure to the fourth side plate to simulate the lateral compacting force exerted on the solid filling material by the compacting mechanism on the hydraulic support during the actual filling process; a plurality of first groove portions are opened at equal intervals along the length direction at the top end of the first side plate, and a plurality of second groove portions are opened at equal intervals along the length direction at the top end of the third side plate; the spacing is used to simulate the cutting depth of the coal mining machine on the coal mining working face; a discharge plate of the same length as the fourth side plate is made, a filling port is opened in the center of the discharge plate, one end of the discharge plate is overlapped in the first groove portion, and the other end is overlapped in the second groove portion, so as to simulate the bottom discharge conveyor suspended on the rear top beam of the hydraulic support.

[0022] The solid filling material compression test device and method provided by the embodiment of the present invention can simulate the filling step and lateral pressure. Considering the mechanical influence of the filling step and lateral pressure on the filling material in the actual filling mining, the fourth side plate is movably arranged, and a pressure component is arranged on the fourth side plate to simulate the lateral tamping force of the solid filling material from the tamping mechanism on the hydraulic support during the actual filling process; and a plurality of unloading plates arranged parallel to the fourth side plate are arranged on the top frame of the first side plate and the third side plate, and the unloading plate has a filling port for filling the filling space, and the unloading plate is used to simulate the bottom unloading conveyor suspended on the rear top beam of the hydraulic support during the actual filling process during the experiment. By setting a plurality of unloading plates, the mechanical influence environment of the solid filling material in the goaf using different filling step distances during the actual filling process is simulated during the experiment. Therefore, the present invention can more realistically simulate the actual stress state of the filling material in the actual filling process, and then the experimental results obtained based on the experimental device and method can more accurately reflect the mechanical properties of the solid filling material in the actual filling mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A schematic diagram of a steel cylinder used for mechanical confined compression testing of existing solid filling materials;

[0025] Figure 2 This is a schematic structural diagram of a solid filling material compression test device capable of simulating filling step distance and lateral pressure according to an embodiment of the present invention;

[0026] Figure 3 The figure is a schematic diagram of a solid filling material compression test process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] It should be clear that in order to more clearly illustrate the present invention, many technical details are described in the following specific embodiments. Those skilled in the art should understand that the present invention can also be implemented without some of the details. In addition, in order to highlight the main purpose of the present invention, some methods, means, parts and their applications well known to those skilled in the art are not described in detail, but this does not affect the implementation of the present invention. The embodiments described herein are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0029] At present, the mechanical property tests or experiments of filling materials are basically carried out by Figure 1The confined compression test device shown in the figure carries out the confined compression test, and uses the electro-hydraulic servo press to compress the solid filling material 4 filled in the steel cylinder 1 through the force transmission rod 2 and the piston 3 at the end, tests its stress-strain curve, and analyzes the mechanical properties of the material. This device is easy to operate and can well reflect the mechanical properties of the filling material to a certain extent. However, in the actual filling process, the filling material will be subjected to the lateral compaction force of the support compaction mechanism in the filling area, and in the filling process, different filling steps will also affect the filling effect. Therefore, under different filling steps and lateral pressure conditions, the filling material may exhibit different mechanical behaviors. However, the existing confined compression test device and method do not take into account the lateral pressure from the support compaction mechanism on the solid filling material in the actual filling process, nor do they take into account the influence of the filling step. Since the existing confined compression test device and method cannot simulate the actual stress state of the filling material in the actual filling process more realistically, the test results based on the existing confined compression test device and method have a certain deviation from the actual deformation and stress process of the filling body.

[0030] To solve the above technical problems existing in the existing confined compression test device and method, see Figure 2 As shown, the solid filling material compression test device capable of simulating filling step and lateral pressure provided by the embodiment of the present invention is suitable for experimental research and analysis of the mechanical properties of solid filling materials in filling mining; the device comprises: a model box, the model box comprises a bottom plate, on which a first side plate 10, a second side plate 20, a third side plate 30 and a fourth side plate 40 are arranged, the space enclosed by the first side plate 10, the second side plate 20, the third side plate 30 and the fourth side plate 40 forms a filling space 50 for simulating a goaf, the first side plate 10 is opposite to the third side plate 30, and is respectively used In the simulated upper and lower drifts of the coal mining working face, the second side plate 20 is opposite to the fourth side plate 40, and the second side plate 20 is used to simulate the opening of the coal wall. The two ends of the fourth side plate 40 are movably connected to the first side plate 10 and the third side plate 30 respectively, and can be moved in the direction of the line connecting the second side plate 20. A pressure component 41 is provided on the fourth side plate 40. Under the push of the pressure component 41, the fourth side plate 40 moves toward the second side plate 20 to simulate the lateral compaction force of the compaction mechanism on the hydraulic support on the solid filling material during the actual filling process.

[0031] A plurality of unloading plates 60 arranged parallel to the fourth side plate 40 are mounted on the top of the first side plate 10 and the third side plate 30. The unloading plates 60 have filling ports for filling the filling space. The unloading plates 60 are used to simulate the bottom-unloading conveyor suspended on the rear top beam of the hydraulic support during the actual filling process. Furthermore, during the experiment, the unloading position point is adjusted using the unloading plates 60 to simulate the mechanical influence of different filling steps on the solid filling material during the actual filling process.

[0032] The solid filling material compression test device provided by the embodiment of the present invention can simulate the filling step and lateral pressure. Taking into account the mechanical influence of the filling step and lateral pressure on the filling material in actual filling mining, the fourth side plate 40 is movably arranged, and a pressure component 41 is arranged on the fourth side plate 40 to simulate the lateral tamping force of the solid filling material from the tamping mechanism on the hydraulic support during the actual filling process during the experiment; and a plurality of unloading plates 60 arranged parallel to the fourth side plate 40 are arranged on the top frame of the first side plate 10 and the third side plate 30, and the unloading plate 60 has a filling port for filling the filling space, and the unloading plate 60 is used to simulate the bottom unloading conveyor suspended on the rear top beam of the hydraulic support during the actual filling process during the experiment. By setting a plurality of unloading plates 60, the mechanical influence environment of the solid filling material in the goaf during the actual filling process is simulated during the experiment. Therefore, the present invention can more realistically simulate the actual stress state of the filling material during the actual filling process, and then the experimental results obtained based on the experimental device can more accurately reflect the mechanical properties of the solid filling material in actual filling mining.

[0033] Among them, in some implementations of the unloading plate 60, a plurality of first groove portions 11 are provided at equal intervals at the top end of the first side plate 10 along the length direction, and a plurality of second groove portions 31 are provided at equal intervals at the top end of the third side plate 30 along the length direction, and the first groove portions 11 are arranged corresponding to the second groove portions 31, and one end of the unloading plate 60 is arranged in the first groove portion 11, and the other end is arranged in the second groove portion 31.

[0034] Specifically, the first groove portion 11 and the second groove portion 31 are semicircular grooves, and both ends of the stripper plate 60 have semicircular overlapping portions, and both ends of the stripper plate 60 are overlapped in the semicircular grooves through the semicircular overlapping portions.

[0035] The unloading plate is a sheet metal part with an arc-shaped cross section made of a metal sheet. The metal sheet refers to a metal sheet with a thickness of 0.2-3 mm. The metal sheet includes an iron plate, a steel plate, an engineering plastic plate, etc. The pressure component 41 is a jack.

[0036] In order to help understand the technical solutions and technical effects provided by the embodiments of the present invention, Figure 2 and Figure 3 , an experimental method based on the solid filling material compression test device provided in this embodiment that can simulate the filling step and lateral pressure is described in detail. The method includes the steps of:

[0037] S10, according to the horizontal distance between the hinge point of the tamping mechanism on the hydraulic support and the base of the hydraulic support and the center of the bottom discharge conveyor in the actual filling mining, adjust the distance from the fourth side plate 40 to the center line of the filling port of the first discharge plate 60 a m .

[0038] The first unloading plate 60 is counted toward the fourth side plate 40 with the second side plate 20 as a reference, that is, the first unloading plate 60 is close to the second side plate.

[0039] In this embodiment, by adjusting the distance from the fourth side plate 40 to the center line of the filling port of the first unloading plate 60 according to the horizontal distance between the hinge point of the compaction mechanism on the hydraulic support and the base of the hydraulic support and the center of the bottom unloading conveyor in actual filling mining, the horizontal distance between the hinge position of the compaction mechanism on the support and the base and the center of the bottom unloading conveyor in actual filling mining can be more realistically simulated, thereby providing an experimental environment or conditions for the experimental results to more accurately reflect the mechanical properties or behaviors of the actual solid filling material in actual filling mining.

[0040] S20, filling material into the filling space through the filling port on the first unloading plate 60, so as to simulate a "mine-one-fill" filling mining mode.

[0041] Among them, "mine one and fill one" is a technical term in backfill mining, which refers to the filling of the goaf formed after mining the first branch tunnel when mining the second branch tunnel; similarly, "mine two and fill one" and "mine n and fill one" mentioned in this article are also technical terms in backfill mining, which will not be repeated here.

[0042] S30. When the filler space is filled with material, the fourth side plate 40 is pushed toward the second side plate 20 by using the pressure component 41 to simulate the lateral compaction process of the compaction mechanism on the hydraulic support.

[0043] In this embodiment, the influence of filling step and lateral pressure on the filling material is taken into account in the structure of the experimental device and the experimental method, so that the measured mechanical properties of the filling material are closer to the actual situation of underground filling. The experimental results obtained can more accurately reflect the mechanical properties and behavior of solid filling materials in actual filling and mining.

[0044] S40. After compaction is completed, the filling material is compressed by an electro-hydraulic servo press, and the volume change rate and strain-stress curve of the compressed filling material are monitored.

[0045] Among them, the electro-hydraulic servo press is a commonly used device in material stretching and compression experiments. It is a prior art. In order to highlight the main purpose of the invention, its structure and function will not be described in detail.

[0046] In the embodiments of the present invention, since the mechanical influence of lateral pressure and filling step distance on the solid filling material in the actual mining process is fully considered, based on the solid filling material compression test device that can simulate the filling step distance and lateral pressure in the aforementioned embodiments, a solid filling material compression test method is provided that can more realistically simulate the actual stress state of the filling material in the actual filling process. The experimental results obtained based on this experimental method can more accurately reflect the mechanical properties of the solid filling material in actual filling mining.

[0047] In some embodiments, the method further includes: changing the position of the filler during the experiment, filling the filler space with material from the filling port on the nth unloading plate 60, to simulate a "mine n and fill one" filling mining mode; wherein n≥1, and n is an integer.

[0048] Based on different filling positions, steps S30 and S40 are repeated respectively to monitor the volume change rate and strain-stress curve of the compressed filling material after each change of the filling position, so as to simulate the mechanical influence of different filling steps on the solid filling material in the actual filling process.

[0049] According to the volume change rate of the compressed filling material and the strain-stress curve obtained each time, the mechanical effects of different filling step distances on the solid filling material are analyzed.

[0050] In this embodiment, by changing the position of the filler during the experiment, the stress state of the solid filling material under different actual filling step conditions can be measured. By comparing and analyzing the experimental results of each experiment provided by this embodiment, the influence of the filling step on the filling material can be more realistically understood, providing theoretical guidance for the practice of filling and mining engineering. For example, filling from the first unloading plate obtains the volume change rate and strain-stress curve of the filling material after one compression, filling from the second unloading plate obtains the volume change rate and strain-stress curve of the filling material after one compression, filling from the third unloading plate obtains the volume change rate and strain-stress curve of the filling material after one compression... In this way, multiple experimental data are obtained, and each experimental data is compared and analyzed, and the influence of the filling step on the filling material is understood based on the analysis results. Among them, Figure 2 In the figure, the d m It is the distance from the fourth side plate 40 to the center line of the filling port of the third unloading plate 60.

[0051] It is understandable that the number of filling point positions can be set as needed, that is, multiple corresponding unloading plates can be set. Figure 2 The three filling point positions illustrated in the figure are for facilitating understanding and should not be regarded as limiting the number of filling point positions (or unloading plates) in this embodiment.

[0052] Furthermore, in theory, the smaller the filling step, the better the filling effect, but the corresponding filling efficiency is lower; conversely, the larger the filling step, the worse the filling effect, but the higher the filling efficiency. In this embodiment, by testing the mechanical properties (reflecting the filling effect) and filling efficiency of the filling material under different filling step conditions, combined with the filling rate required for the actual working face roof control, a reasonable filling step can be determined, providing more accurate theoretical guidance for the filling mining engineering practice.

[0053] In some other embodiments, the method further comprises: in each experiment, changing the thrust of the pressure component 41, specifically the lateral thrust, to simulate the compaction process with different lateral compaction forces.

[0054] The volume change rate and strain-stress curve of the compressed filling material are monitored each time the thrust size is changed to simulate the mechanical impact environment of different lateral compaction forces on the solid filling material during the actual filling process.

[0055] According to the volume change rate of the compressed filling material and the strain-stress curve obtained each time, the mechanical influence of different lateral compaction forces on the solid filling material is analyzed.

[0056] In this embodiment, by changing the lateral thrust during the experiment, the stress state of the solid filling material under different lateral compaction force conditions in the actual working conditions can be measured. By comparing and analyzing the experimental results of each experiment provided in this embodiment, the influence of the lateral pressure on the filling material can be understood more realistically, providing theoretical guidance for the practice of filling mining engineering. Similar to the aforementioned change of the filling position to obtain multiple experimental data, in this embodiment, by changing the thrust size, a set of experimental data is obtained each time. According to different thrust sizes, multiple sets of experimental data can be obtained. By comparing the obtained multiple sets of experimental data, the influence of the lateral pressure on the filling material can be analyzed.

[0057] In some other embodiments, in each experiment, the thrust of the pressure member 41 and the position of the filler are changed, and the volume change rate and strain-stress curve of the compressed filler are monitored after each change of the thrust and the position of the filler, so as to simulate the mechanical influence of different lateral tamping forces and different filling steps on the solid filling material in the actual filling process;

[0058] According to the volume change rate of the compressed filling material and the strain-stress curve obtained each time, the mechanical effects of different lateral tamping forces and filling pitches on the solid filling material are analyzed.

[0059] In this embodiment, by changing the lateral thrust and the unloading position during the experiment, the stress state of the solid filling material under different lateral compaction forces and different filling step distances in the actual working conditions can be measured. By comparing and analyzing the experimental results of each experiment provided by this embodiment, it is possible to have a more realistic and comprehensive understanding of the influence of different lateral compaction forces and different filling step distances on the filling material as a whole, and provide theoretical guidance for the practice of filling mining engineering. Specifically, before step S10, the method further includes: making the solid filling material compression test device that can simulate the filling step distance and lateral pressure;

[0060] Specifically: according to the actual mining height of the coal mining face and the key parameters of the filling hydraulic support, determine the reasonable model similarity ratio α L ; The key parameters include the horizontal distance between the hinge point of the tamping mechanism on the hydraulic support and the base of the hydraulic support and the center of the bottom unloading conveyor.

[0061] Determine the model box size based on the model similarity ratio; wherein, based on the model similarity ratio and formula

[0062] Determine the size of the model box.

[0063] Take three high-strength thick steel plates of equal height, namely the first side plate 10, the second side plate 20 and the third side plate 30, and fix them on the bottom plate to form a box with three fixed sides, which is used to simulate the three-sided closed goaf space in the actual coal mining working face; wherein, the first side plate 10 and the third side plate 30 are respectively connected to the second side plate 20 at an angle of 90°, and the first side plate 10 is opposite to the third side plate 30, that is, the first side plate 10 is parallel to the third side plate 30; the first side plate 10 and the third side plate 30 are respectively used to simulate the upper and lower drifts of the coal mining working face, and the second side plate 20 is used to simulate the open eye coal wall.

[0064] In some implementations, the first side plate 10 , the second side plate 20 , and the third side plate 30 are connected by bolts or fixed by welding.

[0065] In the box body, on a side opposite to the second side surface, a fourth side plate 40 is embedded which can move along the line connecting the second side plate 20, so as to simulate the compacting mechanism of the filling hydraulic support with movable working surface; the second side plate 20 and the fourth side plate 40 are high-strength steel plates of the same material and height;

[0066] A jack is installed on the outer side of the fourth side plate 40 to apply lateral pressure to the fourth side plate 40 to simulate the lateral tamping force of the tamping mechanism on the hydraulic support that the solid filling material is subjected to during the actual filling process;

[0067] A plurality of first grooves 11 are formed at equal intervals along the length direction at the top end of the first side plate 10, and a plurality of second grooves 31 are formed at equal intervals along the length direction at the top end of the third side plate 30; wherein, in some embodiments, the first grooves 11 and the second grooves 31 are semicircular grooves with the same radius, and the spacing b m Used to simulate the cutting depth of the coal mining machine at the coal mining face;

[0068] A discharge plate 60 having the same length as the fourth side plate 40 is made, a filling port is opened at the center of the discharge plate 60, one end of the discharge plate 60 is overlapped in the first groove portion 11, and the other end is overlapped in the second groove portion 31, so as to simulate a bottom discharge conveyor suspended on the rear top beam of the hydraulic support.

[0069] Specifically, an iron sheet with the same length as the fourth side plate 40 and a groove in the middle is made to serve as the unloading plate 60, with its two ends overlapping in the semicircular grooves of the first side plate 10 and the third side plate 30. The iron sheet is used to simulate the bottom-unloading conveyor suspended on the top beam after filling the hydraulic support, and the groove in the middle of the iron sheet is used to simulate the unloading chute of the conveyor.

[0070] In some embodiments, in addition to setting up multiple unloading plates 60, the unloading position can also be changed with only one unloading plate, and the position of the unloading plate 60 can be changed each time according to the simulated filling step. For example: the unloading plate 60 is placed on the first group of first recesses and second recesses close to the second side plate 20, representing "picking one and filling one", and is placed on the second group of first recesses and second recesses away from the second side plate 20, representing "picking two and filling one"... and so on.

[0071] The solid filling material compression test device and method capable of simulating filling pitch and lateral pressure provided in the embodiments of the present invention are based on the scientific discovery of the influence of filling pitch and lateral pressure on the mechanical properties of filling materials in engineering practice, and on the basis of considering the influence of the actual filling factors on the mechanical properties of solid filling materials, a solid filling material compression test device capable of simulating filling pitch and lateral pressure taking into account the filling pitch and lateral pressure is creatively invented, and an experimental method is carried out based on the device, which can solve the problem of deviation between the mechanical properties of filling materials measured by the existing confined compression test and the actual mechanical properties to a certain extent, thereby improving the accuracy and actual reference value of the confined compression test results.

[0072] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A solid filling material compression test method, characterized in that: The solid filling material compression test device capable of simulating filling step and lateral pressure is implemented, and the solid filling material compression test device capable of simulating filling step and lateral pressure comprises: a model box, the model box comprises a bottom plate, and a first side plate, a second side plate, a third side plate and a fourth side plate are arranged on the bottom plate, and the space surrounded by the first side plate, the second side plate, the third side plate and the fourth side plate forms a filling space for simulating a goaf, the first side plate is opposite to the third side plate, and is respectively used to simulate the upper and lower drifts of the coal mining working face, the second side plate is opposite to the fourth side plate, and the second side plate is used to simulate the open-eye coal wall, the two ends of the fourth side plate are respectively movably connected to the first side plate and the third side plate, and can be moved in the direction of the line connecting the fourth side plate, and a pressure component is arranged on the fourth side plate, and under the push of the pressure component, the fourth side plate moves toward the second side plate, so as to simulate the lateral compaction force of the compaction mechanism on the hydraulic support on the solid filling material during the actual filling process; A plurality of unloading plates arranged parallel to the fourth side plate are mounted on the top of the first side plate and the third side plate, and the unloading plates have filling ports for filling materials into the filling space, and the unloading plates are used to simulate the bottom unloading conveyor suspended on the rear top beam of the hydraulic support during the actual filling process; The method comprises the steps of: S10, according to the horizontal distance between the hinge point of the tamping mechanism on the hydraulic support and the base of the hydraulic support and the center of the bottom unloading conveyor in the actual filling mining, adjust the distance from the fourth side plate to the center line of the filling port of the first unloading plate; wherein the first unloading plate is counted toward the fourth side plate with the second side plate as a reference; S20, filling material into the filling space through the filling port on the first unloading plate to simulate a "mine-one-fill" filling mining mode; S30, when the filler space is filled with material, the fourth side plate is pushed toward the second side plate by the pressure member to simulate the lateral compaction process of the compaction mechanism on the hydraulic support; S40, after the compaction is completed, the filling material in the filling space is compressed by the pressure component using an electro-hydraulic servo press, and the volume change rate and strain-stress curve of the compressed filling material are monitored.

2. The solid filling material compression test method according to claim 1, characterized in that: The top end of the first side plate is provided with a plurality of first groove portions at equal intervals along the length direction, and the top end of the third side plate is provided with a plurality of second groove portions at equal intervals along the length direction, and the first groove portions are arranged correspondingly to the second groove portions, and one end of the unloading plate is arranged in the first groove portion, and the other end is arranged in the second groove portion.

3. The solid filling material compression test method according to claim 2, characterized in that: The first groove portion and the second groove portion are semicircular grooves, and both ends of the stripping plate have semicircular overlapping portions, and both ends of the stripping plate are overlapped in the semicircular grooves through the semicircular overlapping portions.

4. The solid filling material compression test method according to claim 1, characterized in that: The stripper plate is a sheet metal part made of a metal sheet and having an arc-shaped cross section.

5. The method according to claim 1, characterized in that The method further comprises: The filling position during the experiment is changed, and the material is filled into the filling space from the filling port on the nth unloading plate to simulate the "mining n and filling one" filling mining mode; n≥1, and n is an integer; Based on different filling positions, steps S30 and S40 are repeated respectively, and the volume change rate and strain-stress curve of the compressed filling material are monitored after each change of the filling material position, so as to simulate the mechanical influence environment of different filling step distances on the solid filling material in the actual filling process; According to the volume change rate of the compressed filling material and the strain-stress curve obtained each time, the mechanical effects of different filling step distances on the solid filling material are analyzed.

6. The method according to claim 1 or 5, characterized in that: The method further comprises: In each experiment, the thrust of the pressure component was changed to simulate the compaction process with different lateral compaction forces; Monitor the volume change rate and strain-stress curve of the compressed filling material after each change in thrust size, so as to simulate the mechanical influence of different lateral tamping forces on the solid filling material during the actual filling process; According to the volume change rate of the compressed filling material and the strain-stress curve obtained each time, the mechanical influence of different lateral compaction forces on the solid filling material is analyzed.

7. The method according to claim 1, characterized in that In each experiment, the thrust of the pressure component and the position of the filler are changed, and the volume change rate and strain-stress curve of the compressed filler are monitored after each change of the thrust and the position of the filler, so as to simulate the mechanical influence of different lateral tamping forces and different filling steps on the solid filling material in the actual filling process; According to the volume change rate of the compressed filling material and the strain-stress curve obtained each time, the mechanical effects of different lateral tamping forces and filling pitches on the solid filling material are analyzed.

8. The method according to claim 3, characterized in that Before step S10, the method further includes: making the solid filling material compression test device capable of simulating the filling step distance and lateral pressure; Specifically, a reasonable model similarity ratio is determined according to the actual mining height of the coal mining face and the key parameters of the hydraulic support for filling; the key parameters include the horizontal distance between the hinge point between the tamping mechanism on the hydraulic support and the base of the hydraulic support and the center of the bottom unloading conveyor; determining a model box size based on the model similarity ratio; Take three high-strength thick steel plates of equal height, namely the first side plate, the second side plate and the third side plate, and fix them on the bottom plate to form a box body with three fixed connections, which is used to simulate the three-sided closed goaf space in the actual coal mining working face; wherein, the first side plate and the third side plate are respectively connected to the second side plate at an angle of 90°, and the first side plate is opposite to the third side plate, the first side plate and the third side plate are respectively used to simulate the upper and lower drifts of the coal mining working face, and the second side plate is used to simulate the open eye coal wall; A fourth side plate is embedded in the box body on a side opposite to the second side plate, and is movable along the line connecting the second side plate, so as to simulate the compacting mechanism of the movable filling hydraulic support on the working surface; the second side plate and the fourth side plate are high-strength steel plates of the same material and height; A jack is installed on the outer side of the fourth side plate to apply lateral pressure to the fourth side plate to simulate the lateral tamping force exerted on the solid filling material by the tamping mechanism on the hydraulic support during the actual filling process; A plurality of first grooves are formed at equal intervals along the length direction at the top of the first side plate, and a plurality of second grooves are formed at equal intervals along the length direction at the top of the third side plate; the intervals are used to simulate the cutting depth of a coal mining machine at a coal mining face; A discharge plate of the same length as the fourth side plate is made, a filling port is opened in the center of the discharge plate, one end of the discharge plate is overlapped in the first groove portion, and the other end is overlapped in the second groove portion to simulate a bottom discharge conveyor suspended on the rear top beam of the hydraulic support.

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