Metal mesh surface stress testing device and method

Abstract

The present invention relates to the technical field of coal mining, and proposes a metal mesh surface stress testing device and method. The metal mesh surface stress testing device includes a support component, a roof model, a metal mesh, a grouting flexible bag, a pressure detection component, an inflation device, and a grouting pump. The lower surface of the roof model is formed with convex parts and / or concave parts, and the metal mesh is arranged below the roof model through a fastening component. The grouting flexible bag is arranged on the upper surface of the metal mesh. The pressure detection component includes a plurality of air bags and a plurality of air pressure sensors, and the air pressure sensors are used to detect the pressure inside the air bags. By arranging convex parts and concave parts on the lower surface of the roof model to simulate the uneven shape of the underground tunnel surface, and by grouting into the interior of the grouting flexible bag to simulate the deformation and squeezing of the tunnel surrounding rock, the support strength of the metal mesh on the upper surrounding rock during the deformation of the mesh bag and the surface stress of the metal mesh are measured.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, and in particular to a metal mesh surface stress testing device and method. Background Art

[0002] As an effective support method, anchor-net support systems are widely used in underground engineering support design. The metal mesh in anchor-net support systems acts as a surface protection component, effectively controlling the collapse of broken rock mass between adjacent anchors. Therefore, the mechanical properties of the metal mesh are a key factor in determining the stability of the support system.

[0003] The main existing method for testing the mechanical properties of metal mesh involves anchoring the mesh to the base of a testing machine. A hydraulic cylinder then applies regional loading to the mesh to simulate deformation of the surrounding rock. The force output of the cylinder is then monitored to determine the mesh's mechanical properties under vertical load, which is then used to determine the mesh's support strength. However, under the same loading conditions, using vertical cylinder loading to simulate deformation of the surrounding rock results in significant differences in the forces applied to the mesh during testing compared to those experienced in situ. Consequently, the resulting test results fail to effectively reflect the mesh's true support strength overall. Summary of the Invention

[0004] The present invention provides a metal mesh surface stress testing device, which accurately simulates the uneven shape of the underground tunnel surface and simulates the deformation of the tunnel surrounding rock to squeeze the metal mesh, thereby measuring the support strength of the metal mesh on the upper surrounding rock during the deformation process of the mesh bag and the surface stress of the metal mesh.

[0005] The invention also provides a metal mesh surface stress testing method.

[0006] A metal mesh surface stress testing device provided according to an embodiment of the first aspect of the present invention includes:

[0007] Bracket components;

[0008] A top plate model is provided on the upper portion of the bracket component, wherein a convex portion and / or a concave portion is formed on the lower surface of the top plate model;

[0009] A metal mesh is provided below the top plate model and is connected to the top plate model via a fastening component;

[0010] A grouting flexible bag is provided on the upper surface of the metal mesh;

[0011] a pressure detection component, comprising a plurality of airbags and a plurality of air pressure sensors, wherein the plurality of airbags are spaced apart and arranged between the lower surface of the roof mold and the grouting flexible bag, the airbags being in communication with the corresponding air pressure sensors, and the air pressure sensors being used to detect the pressure within the airbags;

[0012] an inflation device, connected to each of the airbags via an air delivery pipe, the inflation device being used to inflate air into the airbags;

[0013] The grouting pump is connected to the grouting flexible bag through a liquid infusion tube, and the grouting pump is used to pump cement slurry into the interior of the grouting flexible bag.

[0014] According to the metal mesh surface stress testing equipment provided by an embodiment of the present invention, the uneven shape of the underground tunnel surface is simulated by setting convex and concave parts on the lower surface of the roof model, and the deformation and extrusion of the tunnel surrounding rock are simulated by grouting into the interior of the grouting flexible bag, so as to measure the support strength of the metal mesh on the upper surrounding rock during the deformation of the mesh bag and the surface stress of the metal mesh.

[0015] According to a metal mesh surface stress testing device provided by the present invention, the support component includes:

[0016] Bracket body;

[0017] A frame, the frame being arranged around the outer periphery of the top plate model and connected to the upper portion of the bracket body;

[0018] The tension adjustment component is respectively connected to the frame and the edge of the metal mesh, and the tension adjustment component is used to adjust the tension of the metal mesh in the horizontal direction.

[0019] According to a metal mesh surface stress testing device provided by the present invention, the tension adjustment component includes:

[0020] A driving mechanism connected to the frame;

[0021] A connecting beam connected to the driving mechanism and slidingly engaged with the corresponding frame;

[0022] A plurality of connecting members are arranged at intervals along the length direction of the connecting beam, and the connecting members are respectively connected to the edge of the metal mesh and the connecting beam.

[0023] According to a metal mesh surface stress testing device provided by the present invention, the driving mechanism includes:

[0024] Two manual rollers are rotatably matched with the frame and are threadedly matched with the two ends of the connecting beam in a one-to-one correspondence.

[0025] According to a metal mesh surface stress testing device provided by the present invention, the fastening component includes:

[0026] Anchor rods, the top plate model is provided with a plurality of through holes, and the anchor rods are passed through the through holes;

[0027] a first tray, disposed at the upper end of the anchor rod and abutting against the upper surface of the top plate mold;

[0028] The second tray is arranged at the lower end of the anchor rod and is connected to the metal mesh.

[0029] A metal mesh surface stress testing device provided by the present invention further includes:

[0030] A control console is electrically connected to the inflation device and the grouting pump respectively.

[0031] A metal mesh surface stress testing device provided by the present invention further includes:

[0032] The power distribution cabinet is electrically connected to the control console, the inflation device and the grouting pump respectively.

[0033] According to a second aspect of the present invention, a metal mesh surface stress testing method is provided, which is based on any one of the metal mesh surface stress testing devices described above and includes the following steps:

[0034] Applying a pre-tightening force to the metal mesh by the fastening component so that the pressure in the airbag reaches a first preset pressure;

[0035] Injecting cement slurry into the grouting flexible bag through a grouting pump to deform the metal mesh;

[0036] Get the pressure value detected by the air pressure sensor.

[0037] According to a metal mesh surface stress testing method provided by the present invention, before performing the step of applying a pre-tightening force to the metal mesh by the fastening component, the following steps are further performed:

[0038] Installing the grouting flexible bag on the upper surface of the metal mesh;

[0039] The pressure detection component is installed between the lower surface of the roof model and the grouting flexible bladder. According to a metal mesh surface stress testing method provided by the present invention, after performing the step of installing the pressure detection component between the lower surface of the roof model and the grouting flexible bladder, the following steps are further performed:

[0040] The airbag is inflated by an inflation device.

[0041] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0042] According to the metal mesh surface stress testing equipment provided by an embodiment of the present invention, the uneven shape of the underground tunnel surface is simulated by setting convex and concave parts on the lower surface of the roof model, and the deformation and extrusion of the tunnel surrounding rock are simulated by grouting into the interior of the grouting flexible bag, so as to measure the support strength of the metal mesh on the upper surrounding rock during the deformation of the mesh bag and the surface stress of the metal mesh.

[0043] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 This is a schematic diagram of the assembly of a metal mesh stress testing device provided by an embodiment of the present invention;

[0046] Figure 2 1 is a schematic diagram of the three-dimensional structure of the bracket body provided by an embodiment of the present invention;

[0047] Figure 3 1 is a schematic diagram of a top view of the structure of the bracket body provided by an embodiment of the present invention;

[0048] Figure 4 is a flow chart of a metal mesh surface stress testing method provided by an embodiment of the present invention;

[0049] Figure 5 This is one of the schematic diagrams of the working principle of the metal mesh stress testing device provided by an embodiment of the present invention;

[0050] Figure 6 This is the second schematic diagram of the working principle of the metal mesh stress testing device provided by an embodiment of the present invention.

[0051] Reference numerals:

[0052] 10. Roof model; 11. Metal mesh; 12. Grouting flexible bag; 13. Air bag; 14. Air pressure sensor; 15. Inflating device; 16. Grouting pump; 17. Grouting hole; 18. Air injection port; 21. Frame; 22. Connecting beam; 23. Connecting piece; 24. Manual roller; 25. Bracket body; 31. Anchor rod; 32. First pallet; 33. Second pallet; 34. Nut; 40. Control panel; 50. Power distribution cabinet. DETAILED DESCRIPTION

[0053] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0054] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0055] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0056] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0057] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0058] The following combination Figures 1 to 3 The metal mesh surface stress testing device provided by an embodiment of the present invention is described. Figure 1 The following is a schematic diagram illustrating the assembly of a metal mesh stress testing device provided by an embodiment of the present invention. Figure 2 The following is a schematic diagram illustrating the three-dimensional structure of the bracket body provided by an embodiment of the present invention. Figure 3 The schematic diagram of the top view of the bracket body provided by the embodiment of the present invention is shown as follows: Figures 1 to 3 As shown, the metal mesh surface stress testing device includes a support component, a roof model 10, a metal mesh 11, a grouting flexible bag 12, a pressure detection component, an inflation device 15 and a grouting pump 16. The roof model 10 is arranged on the upper part of the support component, and the lower surface of the roof model 10 is formed with a convex portion and / or a concave portion. The metal mesh 11 is arranged below the roof model 10 and is connected to the roof model 10 by a fastening component. The grouting flexible bag 12 is arranged on the upper surface of the metal mesh 11. The pressure detection component includes a plurality of air bags 13 and a plurality of air pressure sensors 14. The plurality of air bags 13 are arranged at intervals between the lower surface of the roof model 10 and the grouting flexible bag 12. The air bags 13 are connected to corresponding air pressure sensors 14, and the air pressure sensors 14 are used to detect the pressure inside the air bags 13. The inflation device 15 is connected to each air bag 13 through an air supply pipe, and the inflation device 15 is used to inflate the interior of the air bags 13. The grouting pump 16 is connected to the grouting flexible bag 12 through a liquid infusion tube. The grouting pump 16 is used to pump cement slurry into the grouting flexible bag 12 .

[0059] According to the metal mesh surface stress testing equipment provided by an embodiment of the present invention, convex and concave portions are set on the lower surface of the roof model 10 to simulate the uneven surface of the underground tunnel, and grouting is performed into the interior of the grouting flexible bag 12 to simulate the deformation and extrusion of the tunnel surrounding rock. The air bag 13 is thereby used to measure the support strength of the metal mesh 11 on the upper surrounding rock during the deformation of the mesh bag, as well as the surface stress of the metal mesh 11.

[0060] In one embodiment of the present invention, the roof model 10 is a block-shaped structure, with the side surfaces of the roof model 10 threadedly connected to the corresponding frame 21 via bolts. The lower surface of the roof model 10 is formed with convex and / or concave portions. In this embodiment, the lower surface of the roof model 10 is prefabricated with undulating shapes of varying heights to form the convex and concave portions, effectively simulating the uneven surface of an underground tunnel.

[0061] In one embodiment of the present invention, a flexible grouting bladder 12 is disposed on the upper surface of a metal mesh 11. Grouting holes 17 are provided in the flexible grouting bladder 12, which are connected to a grouting pump 16 via a fluid delivery tube. Cement slurry is pumped into the flexible grouting bladder 12 through the grouting holes 17, causing the flexible grouting bladder 12 to expand and exert pressure on the airbag 13 and the metal mesh 11, thereby simulating the pressure exerted on the airbag 13 and the metal mesh 11 during deformation of the surrounding rock of the roadway. The flexible grouting bladder 12 is made of rubber, but the material of the flexible grouting bladder 12 is not limited to this and may also be silicone or other flexible materials.

[0062] In one embodiment of the present invention, the metal mesh surface stress testing device comprises multiple sets of pressure sensing components, each consisting of an airbag 13 and an air pressure sensor 14. The airbags 13 and air pressure sensor 14 are connected via air pipes, and the pressure sensing components are arranged in an array. The airbags 13 are provided with an air injection port 18, which is connected to an inflator 15 via an air pipe. The inflator 15 contains high-pressure nitrogen, which is injected into the airbags 13 through the air injection port 18. The airbags 13 deform to conform to the convex and concave portions of the lower surface of the roof model 10. By monitoring the stress changes on the metal mesh 11 through the airbags 13 and detecting the pressure changes within the airbags 13 through the air pressure sensor 14, the surface stress generated on the metal mesh 11 during the deformation of the surrounding rock in the roadway can be simulated and monitored in real time. The airbags 13 are made of rubber, but the material is not limited to this and can also be made of silicone or other flexible materials.

[0063] It should be noted that the gas pipeline includes a main pipeline and branch pipelines. The main pipeline is connected to the inflation device 15, and the branch pipeline is connected to the gas injection port 18 of the airbag 13. The branch pipeline and the main pipeline are connected through a multi-way connector.

[0064] It should also be noted that while high-pressure nitrogen is injected into the airbag 13 , the air inside the airbag 13 is exhausted to ensure that no external factors affect the measurement of the internal pressure value of the airbag 13 .

[0065] In one embodiment of the present invention, Figure 2 and Figure 3As shown, the bracket assembly includes a bracket body 25, a frame 21, and a tension adjustment assembly. Frames 21 are provided around the perimeter of the top plate model 10. Four frames 21 are connected end-to-end to form a rectangular frame. Frames 21 are connected to the top of the bracket body 25, securing them in place. The tension adjustment assembly is connected to the frame 21 and the edge of the metal mesh 11, respectively, to adjust the horizontal tension of the metal mesh 11.

[0066] In one embodiment of the present invention, four sets of tension adjustment assemblies are provided, each set slidably engaging a corresponding frame 21. The metal mesh 11 has four edges, each of which is connected to a corresponding tension adjustment assembly. The four sets of tension adjustment assemblies are positioned on the same horizontal plane. During installation of the metal mesh 11, the tension of the metal mesh 11 is adjusted by the tension adjustment assemblies to maintain a horizontal position, ensuring effective contact between the airbags 13 and the lower surface of the top plate mold 10.

[0067] In one embodiment of the present invention, the tension adjustment assembly includes a drive mechanism, a connecting beam 22, and multiple connecting members 23. The drive mechanism is connected to the frame 21, and the connecting beam 22 is connected to the drive mechanism and slidably engages with the corresponding frame 21. Multiple connecting members 23 are spaced apart along the length of the connecting beam 22. One end of each connecting member 23 is connected to the connecting beam 22, and the other end is connected to the metal mesh 11. The provision of the connecting beam 22 ensures that each connecting member 23 exerts equal force on the metal mesh 11.

[0068] In one embodiment of the present invention, a slide rail is provided inside the frame 21. The slide rail is perpendicular to the frame 21 and integrally connected to the frame 21. The connecting beam 22 forms a sliding engagement with the slide rail. The connecting beam 22 is threadedly engaged with a drive mechanism, which drives the connecting beam 22 away from or toward the frame 21, thereby adjusting the horizontal tension of the metal mesh 11.

[0069] In one embodiment of the present invention, connectors 23 are threadedly engaged with connecting beam 22. Multiple connectors 23 are arranged equidistantly along the length of connecting beam 22. Connectors 23 transmit the tension generated by the drive mechanism to the metal mesh 11, ensuring that the tension on each connector 23 is as uniform as possible, thus preventing uneven localized force on the metal mesh 11. The frame 21 is provided with a through-hole, through which the ends of the connectors 23, distal from the metal mesh 11, extend. This facilitates adjustment of individual connectors 23, thereby adjusting the local tension of the metal mesh 11.

[0070] In one embodiment of the present invention, the drive mechanism includes two manual rollers 24, which are rotatably engaged with the frame 21 and threadedly engaged with the ends of the connecting beam 22 in a one-to-one correspondence. That is, one manual roller 24 is threadedly engaged with one end of the connecting beam 22, and the other manual roller 24 is threadedly engaged with the other end of the connecting beam 22. By providing two manual rollers 24 with a one-to-one correspondence between the ends of the connecting beam 22, the ends of the connecting beam 22 can be adjusted independently, thereby ensuring uniform force on the entire metal mesh 11.

[0071] It should be noted that the driving mechanism is not limited to manual operation via the manual roller 24 , and may also be electrically driven, such as driven by a screw module, or driven by an air cylinder or an oil cylinder.

[0072] In one embodiment of the present invention, one end of a connector 23 is connected to the edge of the metal mesh 11, and the end of the connector 23 facing away from the metal mesh 11 is threadedly engaged with a connecting beam 22. The connecting beam 22 and the frame 21 are slidably engaged via a slide rail. Two manual rollers 24 are rotationally engaged with the frame 21 and threadedly engage with the ends of the connector 22 in a one-to-one correspondence. The frame 21 is connected to the upper portion of the bracket body 25. By rotating the manual rollers 24, the connecting beam 22 drives the connector 23 toward the frame 21, straightening the metal mesh 11. The end of the connector 23 facing away from the metal mesh 11 extends through the through hole. Adjusting a single connector 23 can adjust the local tension of the metal mesh 11.

[0073] In one embodiment of the present invention, the fastening components include anchor rods 31, a first tray 32, and a second tray 33. The roof form 10 is provided with a plurality of through-holes arranged in an array, and the anchor rods 31 are inserted into the through-holes. The first tray 32 is positioned above the anchor rods 31 and abuts the upper surface of the roof form 10. The second tray 33 is positioned below the anchor rods 31 and connected to the metal mesh 11.

[0074] It should be noted that the grouting flexible bladder 12 is provided with multiple through-holes, and a gap is also formed between the pressure detection components. The anchor rod 31 passes through the through-holes of the roof mold 10 and the through-holes of the grouting flexible bladder 12 and is connected to the metal mesh 11. Nuts 34 are provided at both ends of the anchor rod 31 to secure the first tray 32 and the second tray 33.

[0075] In one embodiment of the present invention, the metal mesh surface stress testing equipment also includes a control console, which is electrically connected to the inflation device 15 and the grouting pump 16 respectively. The control console can control the grouting speed of the grouting pump 16 and the air pressure of the inflation device 15, while monitoring the experimental data and displaying the test results.

[0076] In one embodiment of the present invention, the metal mesh surface stress testing equipment further includes a power distribution cabinet 50, which is electrically connected to the control console, the inflation device 15 and the grouting pump 16 respectively to realize power distribution for the entire experimental system.

[0077] The following combination Figures 4 to 6 Describe the metal mesh surface stress testing method provided by the present invention, Figure 4 The flowchart of the metal mesh surface stress testing method provided by the embodiment of the present invention is illustrated. Figure 5 This is a schematic diagram illustrating the working principle of the metal mesh stress testing device provided by an embodiment of the present invention. Figure 6 The second schematic diagram of the working principle of the metal mesh stress testing device provided by the embodiment of the present invention is illustrated as follows: Figures 4 to 6 As shown, the metal mesh surface stress testing method provided by the present invention is based on the metal mesh surface stress testing device described in any one of the above embodiments, and the metal mesh surface stress testing method includes the following steps:

[0078] Step 110 : applying a pre-tightening force to the metal mesh 11 by a fastening component so that the pressure in the airbag 13 reaches a first preset pressure.

[0079] like Figure 5 As shown, the metal mesh 11 is fixed to the uneven surface of the lower surface of the roof form 10 via anchor rods 31. The grouting flexible bag 12 and the air bag 13 are placed in the space between the metal mesh 11 and the roof form 10. Bolts at the lower ends of the anchor rods 31 enable the second tray 33 to move the metal mesh 11 toward the roof form 10, applying a preload force to the metal mesh 11 to ensure that the pressure in the air bag 13 reaches the first preset pressure P1.

[0080] In step 120 , cement slurry is injected into the grouting flexible bag 12 by the grouting pump 16 , so that the metal mesh 11 is deformed.

[0081] like Figure 6 As shown, after the pre-tightening force is applied to the metal mesh 11, cement slurry is injected into the grouting flexible bag 12 through the grouting pump 16. During the process of injecting cement slurry, the grouting flexible bag 12 gradually expands and drives the metal mesh 11 to deform, thereby simulating the deformation process of the tunnel roof.

[0082] Step 130 , obtaining the pressure value detected by the air pressure sensor 14 .

[0083] like Figure 6As shown, during the deformation of the metal mesh 11, the airbag 13 is further compressed, generating a pressure value. When the grouting flexible bag 12 deforms, the pressure exerted by the grouting flexible bag 12 on the metal mesh 11 is relatively large, causing the metal mesh 11 to deform significantly. The airbag 13 is further compressed, and the pressure sensor 14 detects a value P2, which is the surface stress value at a specific point on the metal mesh 11. By collecting and calculating the detection value P2, we can obtain the support strength of the metal mesh 11 on the upper surrounding rock during the deformation process, as well as the surface stress of the metal mesh 11.

[0084] In one embodiment of the present invention, before performing the step of applying a pre-tightening force to the metal mesh 11 by the fastening component, the following steps are further performed:

[0085] Step 107 : Install the grouting flexible bag 12 on the upper surface of the metal mesh 11 .

[0086] The grouting flexible bag 12 is mounted on the upper surface of the metal mesh 11, and the through holes of the grouting flexible bag 12 are arranged corresponding to the anchor rods 31. The grouting flexible bag 12 is provided with grouting holes 17, which are connected to the grouting pump 16 through a liquid infusion tube.

[0087] Step 108 : Install a pressure detection component between the lower surface of the roof mold 10 and the grouting flexible bag 12 .

[0088] Multiple sets of pressure detection components are evenly installed between the lower surface of the roof model 10 and the grouting flexible bag 12. Each set of pressure detection components includes an airbag 13 and an air pressure sensor 14. The air pressure sensor 14 is connected to the control console via a data cable. A wireless communication module can also be provided to wirelessly connect the air pressure sensor 14 to the control console via the wireless communication module. The wireless communication module can be any one of a 5G communication module, a 4G communication module, a Bluetooth module, a WiFi module, a GSM module, a CDMA module, a WCDMA module, a TD-SCDMA module, a Zigbee module, and a LoRa module, or a combination thereof. An air injection port 18 is provided on the airbag 13, which is connected to the inflation device 15 via an air pipe. The airbag 13 can adapt to the convex and concave portions of the lower surface of the roof model 10 through deformation. The airbag 13 monitors the stress changes on the metal mesh 11, and the air pressure sensor 14 detects the air pressure changes in the airbag 13. This can simulate the surface stress generated on the metal mesh 11 during the deformation of the tunnel surrounding rock and monitor the surface stress in real time.

[0089] In one embodiment of the present invention, after performing the step of installing the pressure detection component between the lower surface of the roof form 10 and the grouting flexible bag 12, the following steps are further performed:

[0090] Step 109 , inflate the airbag 13 through the inflation device 15 .

[0091] The gas that the inflation device 15 injects into the airbag 13 is high-pressure nitrogen. The inflation device 15 fills the interior of the airbag 13 with the high-pressure nitrogen through the gas injection port 18 .

[0092] The metal mesh surface stress testing method provided by the present invention fixes the metal mesh 11 under the roof model 10 through the anchor rod 31, and drives the metal mesh 11 to move toward the roof model 10 by driving the second tray 33, applies a pre-tightening force to the metal mesh 11, and at the same time makes the pressure in the air bag 13 reach a first preset pressure P1; injects cement slurry into the grouting flexible bag 12 through the grouting pump 16, and the grouting flexible bag 12 gradually expands, causing the metal mesh 11 to deform; when the grouting flexible bag 12 is deformed, the pressure on the metal mesh 11 is relatively large, which can cause the metal mesh 11 to deform significantly, and the air bag 13 is further compressed. At this time, the detection value P2 of the air pressure sensor 14 is collected to obtain the support strength of the metal mesh 11 on the upper surrounding rock during the deformation of the mesh bag, as well as the surface stress of the metal mesh 11.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A metal mesh stress testing device, characterized in that: include: Bracket components; A top plate model is provided on the upper portion of the bracket component, wherein a convex portion and / or a concave portion is formed on the lower surface of the top plate model; A metal mesh is provided below the top plate model and is connected to the top plate model via a fastening component; A grouting flexible bag is provided on the upper surface of the metal mesh; a pressure detection component, comprising a plurality of airbags and a plurality of air pressure sensors, wherein the plurality of airbags are spaced apart and arranged between the lower surface of the roof mold and the grouting flexible bag, the airbags being in communication with the corresponding air pressure sensors, and the air pressure sensors being used to detect the pressure within the airbags; an inflation device, connected to each of the airbags via an air delivery pipe, the inflation device being used to inflate air into the airbags; The grouting pump is connected to the grouting flexible bag through a liquid infusion tube, and the grouting pump is used to pump cement slurry into the interior of the grouting flexible bag.

2. The metal mesh surface stress testing device according to claim 1, characterized in that: The bracket component includes: Bracket body; A frame, the frame being arranged around the outer periphery of the top plate model and connected to the upper portion of the bracket body; The tension adjustment component is respectively connected to the frame and the edge of the metal mesh, and the tension adjustment component is used to adjust the tension of the metal mesh in the horizontal direction.

3. The metal mesh surface stress testing device according to claim 2, characterized in that: The tension adjustment assembly comprises: A driving mechanism connected to the frame; A connecting beam connected to the driving mechanism and slidingly engaged with the corresponding frame; A plurality of connecting members are arranged at intervals along the length direction of the connecting beam, and the connecting members are respectively connected to the edge of the metal mesh and the connecting beam.

4. The metal mesh surface stress testing device according to claim 3, characterized in that: The driving mechanism comprises: Two manual rollers are rotatably matched with the frame and are threadedly matched with the two ends of the connecting beam in a one-to-one correspondence.

5. The metal mesh surface stress testing device according to any one of claims 1 to 4, characterized in that: The fastening component comprises: Anchor rods, the top plate model is provided with a plurality of through holes, and the anchor rods are passed through the through holes; a first tray, disposed at the upper end of the anchor rod and abutting against the upper surface of the top plate mold; The second tray is arranged at the lower end of the anchor rod and is connected to the metal mesh.

6. The metal mesh surface stress testing device according to any one of claims 1 to 4, characterized in that: Also includes: A control console is electrically connected to the inflation device and the grouting pump respectively.

7. The metal mesh surface stress testing device according to claim 6, characterized in that: Also includes: The power distribution cabinet is electrically connected to the control console, the inflation device and the grouting pump respectively.

8. A metal mesh surface stress testing method, the testing method being based on the metal mesh surface stress testing device according to any one of claims 1 to 7, characterized in that: The following steps are involved: Applying a pre-tightening force to the metal mesh by the fastening component so that the pressure in the airbag reaches a first preset pressure; Injecting cement slurry into the grouting flexible bag through a grouting pump to deform the metal mesh; Get the pressure value detected by the air pressure sensor.

9. The metal mesh surface stress testing method according to claim 8, characterized in that: Before performing the step of applying a pre-tightening force to the metal mesh by the fastening component, the following steps are further performed: Installing the grouting flexible bag on the upper surface of the metal mesh; The pressure detection component is installed between the lower surface of the roof mold and the grouting flexible bag.

10. The metal mesh surface stress testing method according to claim 9, characterized in that: After performing the step of installing the pressure detection component between the lower surface of the roof mold and the grouting flexible bag, the following steps are further performed: The airbag is inflated by an inflation device.

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