A supporting structure failure model test device and method

Abstract

This invention relates to a test apparatus and method for a failure model of a support structure, comprising multiple pillars, a rock sample support frame between the tops of the pillars, a rock sample support frame having multiple first through holes for support components to pass through, a hollow jack at the bottom of the rock sample support frame at the location of the first through hole, a loading platform below the multiple hollow jacks, the loading platform having second through holes for support components to pass through, the loading platform being detachably connected to a connector, and the connector being connected to a lifting component of the pillar. Using the test apparatus of this invention, the coupled bearing characteristics and instability evolution law of the rock and soil self-properties-anchor bolt-anchor cable-steel strip support structure system can be studied.

Description

Technical Field

[0001] This invention relates to the field of geotechnical support technology, specifically to a test apparatus and method for a failure model of a support structure. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Anchor mesh (and cable) support technology has been widely applied in geotechnical engineering fields such as mining engineering, tunnel support, and slope support. With the extensive application of anchor mesh (and cable) support in actual support projects, research on the local failure patterns, structural damage characteristics, and failure mechanisms of anchor mesh (and cable) support has become increasingly important. The strength of active support systems is characterized by the coupling and superposition of multiple factors, including the properties of the soil and rock mass itself, the diameter of the anchor rod (and cable), the anchorage length, the preload, and the width of the steel strip. Existing testing devices are mostly limited to testing the strength of the support components themselves, and their accuracy cannot be guaranteed. For example, patent application CN108346365A discloses a teaching model for anchor rod pull-out tests that can change the anchor rod support parameters. This model only tests the pull-out of the anchor rod and does not consider the properties of the rock mass itself or factors such as the steel strip. Therefore, existing testing devices lack a systematic approach to studying the coupled bearing characteristics and instability evolution of the soil and rock mass-anchor rod-anchor cable-steel strip support structure system. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a test device for a failure model of a support structure, which can be used to study the coupled bearing characteristics and instability evolution of the rock and soil mass-anchor bolt-anchor cable-steel strip support structure system.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, embodiments of the present invention provide a support structure failure model test device, including multiple pillars, a rock sample support frame between the tops of the multiple pillars, the rock sample support frame having multiple first through holes for support members to pass through, a hollow jack on the bottom surface of the rock sample support frame at the position of the first through hole, a loading platform below the multiple hollow jacks, the loading platform having a second through hole for support members to pass through, the loading platform being detachably connected to a connector, and the connector being connected to a lifting component of the pillar.

[0006] Optionally, a support telescopic component is provided below the rock sample support frame, which passes through the loading platform to support the rock sample support frame.

[0007] Optionally, the support telescopic component is a hydraulic cylinder, which is installed on the base through a groove in the base, and the bottom end of the support column is fixedly connected to the base.

[0008] Optionally, the connector includes a sliding part and a connecting part. The sliding part is slidably connected to the support column and connected to the lifting component provided on the support column. The connecting part cooperates with the connecting plate provided on the loading platform. The connecting part is fixed to the connecting plate of the loading platform by a threaded fastener.

[0009] Optionally, a rock sample holder is detachably fixed to the upper surface of the rock sample support frame for fixing the rock sample.

[0010] Optionally, it also includes an image acquisition element for acquiring images of the support components during the test. The image acquisition element is connected to the processing system and can transmit the acquired images to the processing system.

[0011] Optionally, it also includes an acoustic emission sensor for mounting on the support to be tested, the acoustic emission sensor being connected to an acoustic emission signal acquisition processor, and the acoustic emission signal acquisition processor being connected to a processing system.

[0012] Optionally, it also includes multiple strain detection elements, which are arranged on the support along the axial direction of the support. The strain detection elements are connected to the processing system and can transmit the collected strain data of the support to the processing system.

[0013] Optionally, the lifting component may employ a chain drive mechanism mounted on a support column, wherein the drive chain of the chain drive mechanism is connected to a connecting member, or the lifting component may employ a hydraulic telescopic rod or an electric telescopic rod.

[0014] In a second aspect, embodiments of the present invention provide a method for testing the failure model of the support structure described in the first aspect, comprising the following steps: Prepare a rock sample, wherein the rock sample is equipped with a support component that extends from the bottom surface of the rock sample to the outside of the rock sample; The prepared rock sample is placed on the rock sample support frame, and the support component passes through the hollow jack. The height of the connector and the loading platform is adjusted by the lifting component so that the bottom end of the support component passes through the loading platform and is located below the loading platform. A W-shaped steel belt and a pallet are installed at the bottom of the support component that passes through the loading platform. The W-shaped steel belt is located above the pallet and connects multiple support components into one unit. Disconnect the connector from the loading platform; The hollow jack is used to apply a pull-out load to the support components through a loading platform to conduct a pull-out test on the support components.

[0015] The beneficial effects of this invention are as follows: 1. The experimental apparatus and method of the present invention are equipped with a rock sample carrier capable of holding a rock sample with a support member. Simultaneously, the loading platform has a second through hole for the support member to pass through, allowing the bottom end of the support member to extend below the loading platform and install a W-shaped steel strip and a pallet. The loading platform can apply a load to the W-shaped steel strip and the pallet, thereby applying a pull-out load to the support member. Because rock samples and W-shaped steel strips can be placed during the experiment, considering the inherent characteristics of the rock mass and factors such as the steel strip, the study of the coupled bearing characteristics and instability evolution law of the rock mass's inherent properties-anchor bolt-anchor cable-steel strip support structure system is realized.

[0016] 2. The test apparatus and method of the present invention have a loading platform connected to a lifting component on a support column, which can adjust the height of the loading platform to meet the pull-out requirements of support components of different lengths and improve the applicability of the entire test apparatus.

[0017] 3. The test apparatus and method of the present invention are equipped with telescopic support members, which can support the rock sample support frame during the test, avoiding damage to the rock sample support members when the rock sample itself is under great weight and pull-out force, and ensuring the safety and reliability of the test. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 This is a front view of the overall structure of Embodiment 1 of the present invention; Figure 2 This is a side view of the overall structure of Embodiment 1 of the present invention; Figure 3 This is a top view of the rock sample support frame in Embodiment 1 of the present invention; Figure 4 This is a front view of the connector and loading platform in embodiment 1 of the present invention. Figure 5 This is a side view of the connector and loading platform in embodiment 1 of the present invention. Among them, 1. base, 2. support column, 3. rock sample support frame, 4. anchor bolt, 5. rock sample fixing frame, 6. rock sample, 7. hydraulic hollow jack, 8. loading platform, 9. connector, 9-1. sliding part, 9-2. connecting part, 10. processing system, 11. tray, 12. W steel strip, 13. bolt, 14. hydraulic cylinder, 15. groove, 16. CCD camera, 17. acoustic emission sensor, 18. acoustic emission signal acquisition processor, 19. drill hole. Detailed Implementation

[0020] For ease of description, the use of the words "upper" and "lower" in this invention only indicates that they correspond to the upper and lower directions of the accompanying drawings and do not limit the structure. They are merely for the purpose of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0021] Example 1 This embodiment provides a test device for a failure model of a support structure, such as Figures 1-5 As shown, it includes a base 1, and each of the four corners of the top surface of the base 1 is provided with a support column 2, which is perpendicular to the base 1.

[0022] A rock sample support frame 3 is provided between the tops of the support columns 2. In this embodiment, the rock sample support frame 3 is fixedly connected to the top of the support column 2. In another embodiment, the rock sample support frame 3 is slidably connected to the support column, enabling it to move up and down along the axis of the support column 2. A lifting component is provided on the support column 2, which can drive the rock sample support frame to move up and down. The lifting component can be a chain drive mechanism, an electric lifting rod, or a hydraulic lifting rod.

[0023] The rock sample support frame 3 is divided into multiple test areas. The division of the test areas can be made according to the test requirements. In this embodiment, the rock sample support frame is divided into twelve test areas, which are arranged in two rows.

[0024] Each test zone has a first through hole at its center for the support component to be tested to pass through.

[0025] The support component is an anchor bolt 4 or an anchor cable; in this embodiment, the support component is an anchor bolt 4.

[0026] The upper surface of the rock sample support frame 3 is provided with a rock sample fixing frame 5. The rock sample fixing frame 5 is detachably and fixedly connected to the rock sample support frame 3 by bolts. The rock sample fixing frame 5 is used to fix the rock sample 6 placed on the upper surface of the rock sample support frame.

[0027] The rock sample fixing frame 5 includes a vertical part, a first horizontal part at the bottom end of the vertical part, and a second horizontal part at the top end. The first horizontal part and the second horizontal part extend in opposite directions. The first horizontal part is fixedly connected to the rock sample support frame 3 by bolts. The bottom surface of the second horizontal part is used to contact the top surface of the rock sample 6, thereby realizing the limiting and fixing of the rock sample 6.

[0028] The bottom surface of the rock sample support frame 3 is detachably fixed with multiple hollow jacks by bolts. In this embodiment, the hollow jacks are hydraulic hollow jacks 7. The hydraulic hollow jacks 7 are connected to the hydraulic station through oil pipes. The hydraulic station is connected to the processing system 10 and can receive instructions from the processing system 10 to work. The hydraulic station can supply oil to the hydraulic hollow jacks 7 through oil pipes to drive the hydraulic hollow jacks 7 to work.

[0029] In this embodiment, the oil pipes connected to the hydraulic hollow jacks 7 are all equipped with valves, so that each hydraulic hollow jack 7 can work independently without affecting each other, or can work simultaneously.

[0030] In this embodiment, the position of the hydraulic hollow jack 7 corresponds to the position of the first through hole. Since twelve first through holes are provided, twelve hydraulic hollow jacks 7 are provided. The internal cavity of the hydraulic hollow jack 7 is coaxially arranged with the first through hole.

[0031] In this embodiment, the telescopic part of the hydraulic hollow jack 7 is set downwards, allowing it to extend downwards.

[0032] A loading platform 8 is provided below the hydraulic hollow jack, and connecting plates are provided on both sides of the loading platform 8. The connecting plates are detachably connected to the connecting parts 9 through threaded fasteners.

[0033] In this embodiment, the connector 9 is slidably connected to the two pillars 2 on the same side, and can move vertically up and down along the pillars 2.

[0034] The connector 9 includes a sliding part 9-1 and a connecting part 9-2. The sliding part 9-1 is slidably connected to two pillars 2 on the same side, and the connecting part 9-2 is detachably and fixedly connected to the connecting plate by a threaded fastener.

[0035] In this embodiment, the connecting plate is provided with a first fixing hole, and the connecting part is provided with a second fixing hole that matches the first fixing hole. The threaded fastener uses a bolt 13 and a nut. The bolt 13 passes through the first fixing hole and the second fixing hole and the nut is tightened, thereby fixing the connecting plate and the connecting part, and thus realizing the detachable fixed connection between the loading platform and the connecting part.

[0036] The connector is connected to the lifting component installed on the support column 2.

[0037] In this embodiment, the lifting component adopts a chain drive mechanism, including a driving sprocket, a driven sprocket, and a transmission chain wound between the driving sprocket and the driven sprocket. The transmission chain is connected to the sliding part of the connecting member and can drive the connecting member to perform lifting and lowering movements. The driving sprocket is connected to a motor located on the support column and is driven to rotate by the motor. The driven sprocket is rotatably connected to the support column.

[0038] In other embodiments, the lifting component may be a belt drive mechanism, an electric lifting rod, or a hydraulic lifting rod, etc., which can be set according to actual needs by those skilled in the art.

[0039] The connector is connected to the lifting component, which can drive the loading platform 8 to move up and down through the connector, thereby meeting the pull-out test requirements of support components of different lengths and improving the applicability of the entire test device.

[0040] The loading platform 8 is provided with a second through hole, which is used for the support component to pass through. Therefore, the second through hole is coaxially arranged with the internal cavity of the hydraulic hollow jack 7 and the first through hole.

[0041] After the bolts 13 and nuts between the connector 9 and the loading platform 8 are removed, the hydraulic hollow jack 7 can apply a load to the loading platform 8, and then apply a load to the tray 11 and W steel strip 12 located below the loading platform at the bottom of the support component through the loading platform 8, thereby achieving the application of a pull-out load to the support component.

[0042] In this embodiment, the rock sample support frame 3 must bear the weight of the rock sample 6 and the pull-out load on the support components. Therefore, in order to ensure that the rock sample support frame 3 is not damaged and to ensure the safety and reliability of the test, a support telescopic component is provided below the rock sample support frame 3. In this embodiment, three support telescopic components are provided, which are located in the middle of the base. The base is provided with a groove, which is used to fix the support telescopic components.

[0043] The supporting telescopic component adopts a hydraulic cylinder 14. The cylinder body of the hydraulic cylinder 14 is fixed to the base 1 through the groove 15. The piston rod of the hydraulic cylinder 14 passes through the loading platform 8 and can contact the bottom surface of the rock sample support frame 3 to support the rock sample support frame 3.

[0044] The test apparatus also includes an image acquisition element for acquiring images of the support components during the test. In this embodiment, the image acquisition element is a CCD camera 16, which is connected to the processing system 10 and can transmit the acquired image information to the processing system 10.

[0045] CCD camera 16 is positioned directly in front of the test area to monitor images of the support surface before and after deformation. The digital speckle monitoring and analysis module in processing system 10 can calculate the dynamic damage and yield of the support before and after deformation using the acquired digital image information and a set algorithm. Existing algorithms can be used, and will not be described in detail here.

[0046] The test apparatus also includes an acoustic emission sensor 17, which is used to be installed on the support member. Each support member is equipped with two acoustic emission sensors 17. The two acoustic emission sensors 17 of the same support member are arranged opposite to each other. Both acoustic emission sensors 17 are connected to the acoustic emission signal acquisition processor 18. The acoustic emission sensor 17 is used to monitor and collect the stress waves released by the support member due to damage and fracture under pull-out action.

[0047] Since the support components are partially obscured by components such as the rock sample support frame 3, the loading platform 8, and the hydraulic hollow jack 7, the obscured parts cannot have their strain images captured by the CCD camera 16. Therefore, the test device in this embodiment also includes multiple strain detection elements. The strain detection elements are strain gauges, which are fixed on the support components. Each support component is equipped with multiple strain gauges, which are equally spaced along the axis of the support component. The strain gauges are connected to the processing system and can transmit the collected strain information to the processing system.

[0048] Example 2 This embodiment provides a method for testing the failure model of the support structure as described in Embodiment 1, including the following steps: Step 1: Cast a rock sample using a rock-like material. After curing, drill a hole 19 in the bottom surface of the rock sample 6 and install the support component to be tested. The support component is an anchor rod 4 or an anchor cable. In this embodiment, the support component is an anchor rod 4, and the anchorage length of the anchor rod 4 is determined according to the test design. An acoustic emission sensor 17 and strain gauge are pre-fixed on the anchor rod 4.

[0049] Step 2: After 24 hours, once the anchoring agent has reached its final setting strength, place the prepared rock sample 6 on the upper surface of the rock sample support frame 3. At this time, the anchor rod 4 passes through the first through hole and the internal cavity of the hydraulic hollow jack 7 through the rock sample support frame 3 and the hydraulic hollow jack 7. Fix the rock sample fixing frame 5 to the rock sample support frame 3 with bolts, and use the rock sample fixing frame 5 to fix the rock sample 6.

[0050] Step 3: Adjust the height of the loading platform 8 by using the lifting component so that the anchor rod 4 passes through the second through hole into the loading platform 8, and the bottom end of the anchor rod 4 is located below the loading platform 8.

[0051] Step 4: Install the W-steel strip 12 at the bottom of the anchor bolt 4. The W-steel strip 12 is in contact with the bottom surface of the loading platform 8. The W-steel strip 12 connects multiple anchor bolts 4 in the same row into a whole. Install the tray 11 under the W-steel strip 12 of each anchor bolt 4. The fixing method of the W-steel strip 12 and the tray 11 to the anchor bolt 4 can use existing technology, which will not be described in detail here.

[0052] Step 5: Remove the bolts 13 and nuts between the connector 9 and the connecting plate of the loading platform 8, so that the connector 9 is separated from the loading platform 8 and the loading platform 8 is in a suspended state.

[0053] Step 6: The hydraulic hollow jack 7 operates, causing its telescopic part to fit tightly against the loading platform 8.

[0054] Step 7: The piston rod of the hydraulic cylinder 14 on the base 1 extends, so that the piston rod contacts the bottom surface of the rock sample support frame 3, and supports the rock sample support frame 3.

[0055] Step 8: The hydraulic station controls the hydraulic hollow jack 7 to load and pull the anchor bolt 4. At the same time, the acoustic emission sensor 17, CCD camera 16, and strain gauge begin to collect information on the anchor bolt.

[0056] The CCD camera 16 captures one image per second during the initial stage of anchor bolt pull-out. When the anchor bolt 4 tends to be damaged, the acquisition frequency increases to two images per second. The sampling frequency of the acoustic emission sensor 17 is set to 1MHz.

[0057] The experimental apparatus and method of this embodiment can set up rock sample 6 and W steel strip 12 during the test. Therefore, considering the characteristics of the rock mass itself and the steel strip, the study of the coupled bearing characteristics and instability evolution law of the rock and soil mass self-property-anchor bolt-anchor cable-steel strip support structure system is realized.

[0058] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A test apparatus for a failure model of a support structure, characterized in that, It includes multiple pillars, with a rock sample support frame between the tops of the pillars. The rock sample support frame has multiple first through holes for the support components to pass through. A hollow jack is provided on the bottom surface of the rock sample support frame at the location of the first through hole. A loading platform is provided below the multiple hollow jacks. The loading platform has a second through hole for the support components to pass through. The loading platform is detachably connected to the connector, and the connector is connected to the lifting component of the pillar. The rock sample support frame is equipped with a support telescopic component below it, which passes through the loading platform to support the rock sample support frame; The support telescopic component uses a hydraulic cylinder, which is installed on the base through a groove in the base, and the bottom end of the support column is fixedly connected to the base. The connector includes a sliding part and a connecting part. The sliding part is slidably connected to the support column and connected to the lifting component provided on the support column. The connecting part cooperates with the connecting plate provided on the loading platform. The connecting part is fixed to the connecting plate of the loading platform by a threaded fastener. A W-shaped steel strip is installed at the bottom of the anchor bolt. The W-shaped steel strip is in contact with the bottom surface of the loading platform. The W-shaped steel strip connects multiple anchor bolts in the same row into a whole. A tray is installed under the W-shaped steel strip of each anchor bolt.

2. The support structure failure model test device as described in claim 1, characterized in that, The upper surface of the rock sample support frame is detachably fixed with a rock sample fixing frame for fixing the rock sample.

3. The support structure failure model test device as described in claim 1, characterized in that, It also includes an image acquisition element for acquiring images of the support components during the test. The image acquisition element is connected to the processing system and can transmit the acquired images to the processing system.

4. The support structure failure model test device as described in claim 1, characterized in that, It also includes an acoustic emission sensor for mounting on the support structure to be tested. The acoustic emission sensor is connected to an acoustic emission signal acquisition processor, which is connected to a processing system.

5. The support structure failure model test device as described in claim 1, characterized in that, It also includes multiple strain detection elements, which are arranged on the support along the axial direction of the support. The strain detection elements are connected to the processing system and can transmit the collected strain data of the support to the processing system.

6. The support structure failure model test device as described in claim 1, characterized in that, The lifting component adopts a chain drive mechanism installed on the support column, and the transmission chain of the chain drive mechanism is connected to the connecting piece, or the lifting component adopts a hydraulic telescopic rod or an electric telescopic rod.

7. A method for testing a failure model of a support structure according to any one of claims 1-6, characterized in that, Includes the following steps: Prepare a rock sample, wherein the rock sample is equipped with a support component that extends from the bottom surface of the rock sample to the outside of the rock sample; The prepared rock sample is placed on the rock sample support frame, and the support component passes through the hollow jack. The height of the connector and the loading platform is adjusted by the lifting component so that the bottom end of the support component passes through the loading platform and is located below the loading platform. A W-shaped steel belt and a pallet are installed at the bottom of the support component that passes through the loading platform. The W-shaped steel belt is located above the pallet and connects multiple support components into one unit. Disconnect the connector from the loading platform; The hollow jack is used to apply a pull-out load to the support components through a loading platform to conduct a pull-out test on the support components.

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