Hydraulic tunnel lining model internal and external water pressure experiment and monitoring system and use method thereof

Abstract

The invention discloses a hydraulic tunnel lining model internal and external water pressure experiment and monitoring system and a use method thereof. The system comprises a model loading device and a deformation observation system. The model loading device comprises a base, a cover plate, an outer pressure cylinder and an inner pressure cylinder, the inner pressure cylinder and the outer pressure cylinder are made of transparent materials and are tightly connected with the base and the cover plate, and waterproofness and connectivity are guaranteed. The tunnel lining and the inner pressure cylinder form an inner hydraulic pressure chamber, and the tunnel lining and the outer pressure cylinder form an outer hydraulic pressure chamber. And internal and external water pressures are respectively applied through internal and external loading members. According to the system and the method, the inner pressure cylinder and the outer pressure cylinder are made of transparent materials, digital speckle measuring points or equidistant measuring grids are arranged on the inner surface and the outer surface of the lining model, the lining is immersed in a paraffin solution after being dried and formed to generate a low-permeability lining model, and the measuring points or the measuring grids which are not deformed or blurred after being immersed in water. And the amplification effect of the arc-shaped water tank is superposed, and crack initiation and deformation behaviors of the inner and outer surfaces of the lining are captured through non-contact observation, so that an important basis is provided for reinforcement design.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic tunnels, and particularly relates to an internal and external water pressure experiment and monitoring system for a hydraulic tunnel lining model and a using method thereof. Background Art

[0002] A hydraulic tunnel is an underground passage used for water conveyance, water diversion, flood discharge or drainage in a water conservancy project, and usually passes through mountains or underground rock formations. With the accelerating process of urbanization, there are more and more long-distance water supply projects. Most long-distance water conveyance tunnels have to pass through mountainous areas with complex geological structures in the western region. The tunnels have a large buried depth, high in-situ stress, and complex geological conditions. During the operation of the tunnels, the surrounding rock-lining structure will be subjected to large surrounding rock pressure and internal and external water pressure. Whether the lining structure of the tunnel is stable is directly related to the implementation of the entire water conveyance project.

[0003] However, at present, the mechanism of lining bearing and crack propagation under the action of internal and external water pressure in deeply buried hydraulic tunnels is unclear, which has long troubled the lining design work of deeply buried hydraulic tunnels. Model experiments are a reliable means to intuitively study the cracking of the lining of a hydraulic tunnel and the crack propagation direction. Therefore, a large number of lining model experiments under the action of internal and external water pressure have been carried out.

[0004] However, during the process of applying internal and external water pressure to the lining of a hydraulic tunnel in the existing model experiment, only the strain measurement of the lining is carried out to analyze the cracks, and the crack initiation and development evolution process cannot be known, resulting in inaccurate model test results. Summary of the Invention

[0005] Based on this, in view of the problem that the existing model loading device only measures the strain of the lining to analyze the cracks, and the crack initiation and development evolution process cannot be known, resulting in inaccurate model test results, it is necessary to provide an internal and external water pressure experiment and monitoring system for a hydraulic tunnel lining model and a using method thereof.

[0006] An internal and external water pressure experiment and monitoring system for a hydraulic tunnel lining model includes:

[0007] A model loading device, including a base, a cover plate, an external pressure cylinder and an internal pressure cylinder. The external pressure cylinder and the internal pressure cylinder are coaxially arranged between the base and the cover plate. The external pressure cylinder and the internal pressure cylinder are made of transparent materials. A tunnel lining is arranged between the internal pressure cylinder and the external pressure cylinder. The tunnel lining and the internal pressure cylinder form an internal water pressure chamber, and the tunnel lining and the external pressure cylinder form an external water pressure chamber. The cover plate is provided with a through hole for external equipment to enter the internal pressure cylinder; and

[0008] The water pressure loading device includes an internal water pressure loading mechanism and an external water pressure loading mechanism. The internal water pressure loading mechanism is connected to the internal water pressure chamber and is used to provide water to the internal water pressure chamber; the external water pressure loading mechanism is connected to the external water pressure chamber and is used to provide water to the external water pressure chamber.

[0009] In one of the embodiments, it also includes a lining production mold, the lining production mold is provided with a molding cavity, the width of the molding cavity in the radial direction is greater than the width of the tunnel lining, the gap between the tunnel lining and the molding cavity is filled with paraffin powder, the tunnel lining is made of gypsum, the lining production mold is heated to melt the paraffin, and the paraffin is immersed in the tunnel lining.

[0010] In one of the embodiments, a heat-insulating bracket is provided in the molding cavity, and the tunnel lining is supported on the heat-insulating bracket.

[0011] In one of the embodiments, the surface of the tunnel lining is provided with image feature points, and the image feature points include at least one of digital speckle and grid lines.

[0012] In one embodiment, the model loading device further comprises a first fixing block, the first fixing block is provided with a groove for inserting the outer pressure cylinder, and the first fixing block is mounted on the base; and / or

[0013] The model loading device further comprises a second fixing block, the second fixing block is provided with a groove for inserting the inner pressure cylinder, and the second fixing block is mounted on the base.

[0014] In one embodiment, the cover plate is provided with a first exhaust hole communicating with the internal water pressure chamber, and a detachable first sealing member is installed in the first exhaust hole; and / or

[0015] The cover plate is provided with a second exhaust hole communicated with the external water pressure chamber, and a detachable second sealing member is installed in the second exhaust hole.

[0016] In one embodiment, a first channel connected to the internal water pressure chamber is provided in the base, and the first channel passes through the side of the base and is connected to the internal water pressure loading mechanism; and / or

[0017] A second channel communicating with the external water pressure chamber is provided in the base, and the second channel passes through the side surface of the base and communicates with the external water pressure loading mechanism.

[0018] In one embodiment, the internal water pressure loading mechanism and the external water pressure loading mechanism have the same structure and both include a water adding bucket and a pressure volume controller. The water provided by the water adding bucket is transported to the corresponding water pressure chamber through the pressure volume controller.

[0019] A method for using the internal and external water pressure experiment and monitoring system of a hydraulic tunnel lining model as described in any one of the above, the method comprising the following steps:

[0020] Provide a tunnel lining and form image feature points on the surface of the tunnel lining;

[0021] Place the tunnel lining between the external pressure cylinder and the internal pressure cylinder, and then install the cover plate on the tops of the external pressure cylinder, the tunnel lining and the internal pressure cylinder;

[0022] Connect the internal water pressure loading mechanism to the internal water pressure chamber and connect the external water pressure loading mechanism to the external water pressure chamber. Optionally start the internal water pressure loading mechanism and the external water pressure loading mechanism to fill the internal water pressure chamber and / or the external water pressure chamber with water to simulate the action of water pressure on the tunnel lining;

[0023] The data acquisition device collects the surface image information of the tunnel lining through the external pressure cylinder and the internal pressure cylinder to obtain the deformation and crack evolution process of the tunnel lining.

[0024] In one embodiment, the tunnel lining is made of gypsum. After the step of forming image feature points on the surface of the tunnel lining, the following steps are further included:

[0025] Place the tunnel lining with image feature points into the forming cavity of the lining preparation mold, and then add paraffin powder to fill the gap between the tunnel lining and the forming cavity;

[0026] Heat the paraffin powder through the heating wire in the lining preparation mold to melt it into paraffin solution, so that the paraffin fully penetrates into the tunnel lining;

[0027] After the paraffin cools and solidifies, take out the tunnel lining from the forming cavity.

[0028] For the above internal and external water pressure experiment and monitoring system of the hydraulic tunnel lining model and its using method, since both the internal pressure cylinder and the external pressure cylinder are made of transparent materials, they can not only withstand the water pressure in the experiment, but also provide a clear observation field of view. At the same time, through the magnifying effect of the water pressure, the cracks of the lining are more obvious, and the crack initiation and propagation behaviors of the lining under the action of internal and external water pressure can be intuitively captured. Therefore, the data acquisition device can collect the surface image information of the tunnel lining through the external pressure cylinder and the internal pressure cylinder, analyze and obtain the deformation and crack evolution process of the lining, and ensure the accuracy of the model test results. The visualized data can intuitively display the stress concentration area, crack initiation position and propagation path on the surface of the lining, providing an important basis for subsequent mechanical analysis. Brief Description of the Drawings

[0029] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings required for the specific embodiments will be briefly introduced below. In all the drawings, the components or parts are not necessarily drawn to actual scale.

[0030] Figure 1 It is a schematic structural diagram of the internal and external water pressure experiment and monitoring system for the lining model of a hydraulic tunnel in an embodiment;

[0031] Figure 2 It is Figure 1 a three-dimensional view of the model loading device in

[0032] Figure 3 It is Figure 2 a cross-sectional view of the model loading device shown;

[0033] Figure 4 It is Figure 1 an exploded view of the model loading device shown;

[0034] Figure 5 It is a schematic structural diagram of the internal / external water pressure loading mechanism;

[0035] Figure 6 It is a schematic structural diagram of a lining production mold in an embodiment;

[0036] Figure 7 It is a flowchart of the usage method of the internal and external water pressure experiment and monitoring system for the lining model of a hydraulic tunnel in an embodiment;

[0037] Figure 8 It is a schematic diagram of forming image feature points on the surface of the tunnel lining;

[0038] Figure 9 It is a flowchart of heating paraffin by the lining production mold to make the paraffin penetrate into the lining;

[0039] Figure 10 It is a schematic diagram of the digital speckle device and the calibration process.

[0040] Reference numerals:

[0041] 1 - Tunnel lining, 2 - Paraffin, 10 - Model loading device, 11 - Base, 111 - First channel, 112 - Second channel, 12 - Cover plate, 121 - Through hole, 122 - First exhaust hole, 123 - First seal, 124 - Second exhaust hole, 125 - Second seal, 13 - Outer pressure cylinder, 14 - Inner pressure cylinder, 15 - First fixing block, 16 - Second fixing block, 17 - Flexible rubber, 20 - Water pressure loading device, 21 - Inner water pressure loading mechanism, 22 - Outer water pressure loading mechanism, 23 - Water adding bucket, 24 - Pressure volume controller, 25 - Valve, 30 - Inner water pressure chamber, 40 - Outer water pressure chamber, 50 - Lining manufacturing mold, 51 - Forming cavity, 52 - Heating wire, 53 - Heat insulation bracket, 60 - Camera, 61 - Calibration plate. Detailed implementation manners

[0042] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific implementations disclosed below.

[0043] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation manners.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0045] Please refer to Figure 1 , in a water conveyance tunnel lining model internal and external water pressure experiment and monitoring system in an embodiment, including a model loading device 10 and a water pressure loading device 20.

[0046] Please refer to together Figures 2 to 4, the model loading device 10 is used to provide a scenario of internal and external water pressures of the lining. The model loading device 10 includes a base 11, a cover plate 12, an external pressure cylinder 13, and an internal pressure cylinder 14. The external pressure cylinder 13 and the internal pressure cylinder 14 are annular structures, and the external pressure cylinder 13 and the internal pressure cylinder 14 are coaxially arranged between the base 11 and the cover plate 12. A tunnel lining 1 is provided between the internal pressure cylinder 14 and the external pressure cylinder 13. The tunnel lining 1 and the internal pressure cylinder 14 form an internal water pressure chamber 30, and the tunnel lining 1 and the external pressure cylinder 13 form an external water pressure chamber 40. The cover plate 12 is provided with a through hole 121 for an external device to enter the internal pressure cylinder 14, so as to facilitate an external data acquisition device to acquire data inside the internal pressure cylinder 14.

[0047] In an embodiment, the model loading device 10 further includes a first fixing block 15. Positioning grooves for positioning the external pressure cylinder 13 are provided on the base 11 and the cover plate 12. The first fixing block 15 is located outside the external pressure cylinder 13 and is mounted on the base 11 to achieve the limitation and support of the external pressure cylinder 13. Specifically, the first fixing block 15 is detachably mounted on the base 11 by screws or bolts.

[0048] In an embodiment, the model loading device 10 further includes a second fixing block 16. Positioning grooves for positioning the internal pressure cylinder 14 are provided on the base 11 and the cover plate 12. The second fixing block 16 is located inside the internal pressure cylinder 14, and the second fixing block 16 is mounted on the base 11 to achieve the limitation and support of the internal pressure cylinder 14. Specifically, then the second fixing block 16 is detachably mounted on the base 11 by screws or bolts.

[0049] In an embodiment, grooves for installing the tunnel lining 1 are provided on the base 11 and the cover plate 12 to achieve the positioning and fixing of the tunnel lining 1. At the same time, a flexible rubber 17 is provided in the groove to achieve the sealing and separation of the external water pressure chamber 40 and the internal water pressure chamber 30. It can be understood that the flexible rubber 17 can also be arranged in the positioning grooves for positioning the external pressure cylinder 13 and the internal pressure cylinder 14 on the base 11 and the cover plate 12 to achieve the sealing of the internal water pressure chamber 30 and the external water pressure chamber 40. Waterproof tapes are provided at the connection parts of the external pressure cylinder 13 and the internal pressure cylinder 14 with the base 11 and the cover plate 12 to further achieve the sealing of the internal water pressure chamber 30 and the external water pressure chamber 40.

[0050] In one embodiment, a first exhaust hole 122 communicating with the inner water pressure chamber 30 is provided on the cover plate 12, and the air in the inner water pressure chamber 30 can be discharged through the first exhaust hole 122. A detachable first seal 123 is installed in the first exhaust hole 122. After the gas in the inner water pressure chamber 30 is emptied, the first exhaust hole 122 is sealed by the first seal 123 to seal the inner water pressure chamber 30. Specifically, the first seal 123 is a bolt, and the first seal 123 is threadedly connected in the first exhaust hole 122. It can be understood that in other embodiments, the first seal 123 can also be other structures as long as the first exhaust hole 122 can be sealed, such as using a sealing plug, etc.

[0051] In one embodiment, a second exhaust hole 124 communicating with the outer water pressure chamber 40 is provided on the cover plate 12, and the air in the outer water pressure chamber 40 can be discharged through the second exhaust hole 124. A detachable second seal 125 is installed in the second exhaust hole 124. After the gas in the outer water pressure chamber 40 is emptied, the second exhaust hole 124 is sealed by the second seal 125 to seal the outer water pressure chamber 40. Specifically, the second seal 125 is a bolt, and the second seal 125 is threadedly connected in the second exhaust hole 124. It can be understood that in other embodiments, the second seal 125 can also be other structures as long as the second exhaust hole 124 can be sealed, such as using a sealing plug, etc.

[0052] The outer pressure cylinder 13 and the inner pressure cylinder 14 are made of transparent materials, and the crack propagation process on the inner and outer sides of the lining under the action of water pressure can be directly observed through the outer pressure cylinder 13 and the inner pressure cylinder 14. In one embodiment, the outer pressure cylinder 13 and the inner pressure cylinder 14 are made of transparent glass materials, which can not only withstand the high water pressure in the experiment but also provide a clear observation field of view, and can intuitively capture the crack initiation and propagation behavior of the lining under the action of internal and external water pressures. At the same time, the transparent glass has the effect of magnifying cracks, and the crack expansion can be observed more accurately. It can be understood that in other embodiments, the outer pressure cylinder 13 and the inner pressure cylinder 14 can also be made of other materials, such as transparent plastic materials.

[0053] Please refer to again Figure 1 , the water pressure loading device 20 is the core part of the test device and is used to simulate the mechanical behavior of the hydraulic tunnel lining 1 under the action of internal and external water pressures. In one embodiment, the water pressure loading device 20 includes an inner water pressure loading mechanism 21 and an outer water pressure loading mechanism 22. The inner water pressure loading mechanism 21 communicates with the inner water pressure chamber 30 and is used to supply water to the inner water pressure chamber 30; the outer water pressure loading mechanism 22 communicates with the outer water pressure chamber 40 and is used to supply water to the outer water pressure chamber 40.

[0054] Please refer to together Figure 5, in one embodiment, the internal water pressure loading mechanism 21 and the external water pressure loading mechanism 22 have the same structure, both including a water addition bucket 23 and a pressure - volume controller 24. The water addition bucket 23 is used to provide a water source, and the pressure - volume controller 24 is connected to the water addition bucket 23 and the water pressure chamber. The pressure - volume controller 24 is used to precisely adjust the magnitude of the water pressure to ensure the stability and accuracy of the water pressure during the experiment. In one embodiment, a valve 25 is provided between the water addition bucket 23 and the pressure - volume controller 24. The tester can choose to load the internal and external water pressures simultaneously, or load the internal pressure or the external pressure separately, so as to simulate different working conditions.

[0055] Please refer to Figure 4 , in one embodiment, a first channel 111 communicating with the internal water pressure chamber 30 is provided in the base 11. The first channel 111 penetrates the side surface of the base 11 and is connected to the internal water pressure loading mechanism 21. Since the outlet of the first channel 111 is located on the side surface of the base 11, it is convenient for the connection between the first channel 111 and the internal water pressure loading mechanism 21. A second channel 112 communicating with the external water pressure chamber 40 is provided in the base 11. The second channel 112 penetrates the side surface of the base 11 and is connected to the external water pressure loading mechanism 22. Since the outlet of the second channel 112 is located on the side surface of the base 11, it is convenient for the connection between the second channel 112 and the external water pressure loading mechanism 22.

[0056] In one embodiment, image feature points are provided on the surface of the tunnel lining 1. The image feature points include at least one of digital speckles and grid lines, so as to facilitate subsequent performance testing and analysis. In this embodiment, image feature points are provided on both the inner and outer surfaces of the tunnel lining 1, and the image feature points include a combination of digital speckles and grid lines.

[0057] Currently, the tunnel lining 1 is generally made of gypsum. However, gypsum lining materials have deficiencies in waterproofness and water - sensitivity resistance, resulting in a decline in structural performance and being unable to accurately simulate the actual situation of the tunnel lining 1. At the same time, after the gypsum tunnel lining 1 is soaked in water subsequently, the image feature points on the surface of the tunnel lining 1 will be damaged, resulting in the inability to perform data collection subsequently.

[0058] Please refer to Figure 6, therefore, in one embodiment, the internal and external water pressure experiment and monitoring system for the hydraulic tunnel lining model further includes a lining production mold 50. The lining production mold 50 is provided with a forming cavity 51, and the width of the forming cavity 51 in the radial direction is greater than the width of the tunnel lining 1 in the radial direction. Therefore, after the tunnel lining 1 is placed into the forming cavity 51, a gap is formed between the tunnel lining 1 and the forming cavity 51. The gap between the tunnel lining 1 and the forming cavity 51 is filled with paraffin 2 powder. The lining production mold 50 heats and melts the paraffin 2, so that the tunnel lining 1 is completely immersed in the paraffin 2 solution. The paraffin 2 can penetrate into the tunnel lining 1. After the paraffin 2 cools and solidifies, the lining material has the characteristics of low permeability and low water sensitivity, so as to accurately simulate the mechanical properties of the actual tunnel lining 1.

[0059] In one embodiment, a heating wire 52 is provided inside the lining production mold 50. The heating wire 52 heats and melts the paraffin 2 powder, and the heating wire 52 is arranged at the bottom of the lining production mold 50. An insulating support 53 is provided inside the forming cavity 51, and the tunnel lining 1 is carried on the insulating support 53 to avoid direct contact between the tunnel lining 1 and the heating surface and prevent the lining from being damaged due to high temperature.

[0060] Please refer to Figure 7 , the present invention also provides a method for using the internal and external water pressure experiment and monitoring system for the hydraulic tunnel lining model. Specifically, the method includes the following steps:

[0061] Step S110: Provide the tunnel lining 1 and form image feature points on the surface of the tunnel lining 1.

[0062] Please refer to Figure 8 , specifically, the tunnel lining 1 is prepared with gypsum material. After the tunnel lining 1 is cured, digital speckles with a diameter of 3 mm that are uniform, clear and non-overlapping are rolled on the lining surface, and grid lines are printed on the lining surface in two ways to provide sufficient image feature points for subsequent performance testing and analysis.

[0063] Please refer to Figure 9 , in one embodiment, after forming image feature points on the surface of the tunnel lining 1, it further includes: putting the tunnel lining 1 with the image feature points into the forming cavity 51 of the lining preparation mold, and then adding paraffin 2 powder to fill the gap between the tunnel lining 1 and the forming cavity 51. The heating wire 52 in the lining preparation mold is used to heat the paraffin 2 powder to melt and form a paraffin 2 solution, and it is continuously heated at a temperature of 60 °C for 5 to 6 hours to ensure that the paraffin 2 fully penetrates into the lining material. After the paraffin 2 cools and solidifies, the tunnel lining 1 is taken out of the forming cavity 51, and the lining material has the characteristics of low permeability and low water sensitivity. After the image feature points are successfully made, through the shaping of the paraffin 2, the problem of blurring and deformation of the measurement points after being stained by water under the action of high water pressure can be avoided.

[0064] Step S120: Place the tunnel lining 1 between the outer pressure cylinder 13 and the inner pressure cylinder 14, and then install the cover plate 12 on the tops of the outer pressure cylinder 13, the tunnel lining 1, and the inner pressure cylinder 14.

[0065] Please refer to Figure 3 , specifically, first assemble the model loading device 10. Insert the outer pressure cylinder 13 into the positioning groove of the base 11, and install the first fixing block 15 on the base 11 with bolts. Then, insert the inner pressure cylinder 14 into the corresponding positioning groove of the base 11, and install the second fixing block 16 on the base 11 with bolts.

[0066] Install the flexible rubber 17 in the groove of the base 11, and then place the tunnel lining 1 in the groove of the base 11. At this time, the tunnel lining 1 is located between the outer pressure cylinder 13 and the inner pressure cylinder 14. Finally, install the cover plate 12 so that the outer pressure cylinder 13 and the inner pressure cylinder 14 are aligned with the positioning groove of the cover plate 12, and the tunnel lining 1 is aligned with the groove of the cover plate 12. The cover plate 12 is inserted downward onto the tops of the outer pressure cylinder 13, the tunnel lining 1, and the inner pressure cylinder 14. At this time, an inner water pressure chamber 30 is formed between the tunnel lining 1 and the inner pressure cylinder 14, and an outer water pressure chamber 40 is formed between the tunnel lining 1 and the outer pressure cylinder 13.

[0067] Step S130: Connect the inner water pressure loading mechanism 21 to the inner water pressure chamber 30, and connect the outer water pressure loading mechanism 22 to the outer water pressure chamber 40. Optionally, start the inner water pressure loading mechanism 21 and the outer water pressure loading mechanism 22 to fill the inner water pressure chamber 30 and / or the outer water pressure chamber 40 with water to simulate the action of water pressure on the tunnel lining 1.

[0068] Please refer to Figure 1 and Figure 4 , specifically, connect the inner water pressure loading mechanism 21 to the first channel 111 on the side of the base 11 through a tee joint, and connect the outer water pressure loading mechanism 22 to the second channel 112 on the side of the base 11 through a tee joint, so as to connect the inner water pressure loading mechanism 21 to the inner water pressure chamber 30 and connect the outer water pressure loading mechanism 22 to the outer water pressure chamber 40.

[0069] Control the on-off of the water flow through the valve 25 between the water filling bucket 23 and the pressure-volume controller 24. The tester can choose to load the inner and outer water pressures simultaneously, or load the inner pressure or the outer pressure separately, so as to simulate different working conditions. During the water filling process of the inner water pressure chamber 30 and the outer water pressure chamber 40, the first exhaust hole 122 and the second exhaust hole 124 need to be opened so that the gas in the inner water pressure chamber 30 and the outer water pressure chamber 40 is discharged to the outside under the push of the filled water. After the inner water pressure chamber 30 and the outer water pressure chamber 40 are filled with water, screw the sealing screws into the first exhaust hole 122 and the second exhaust hole 124 to seal the inner water pressure chamber 30 and the outer water pressure chamber 40.

[0070] Step S140: The data acquisition device collects the surface image information of the tunnel lining 1 through the outer pressure cylinder 13 and the inner pressure cylinder 14 to obtain the deformation and crack evolution process of the tunnel lining 1.

[0071] Specifically, the data acquisition device is a digital speckle device. The digital speckle device includes a camera 60. The height of the camera 60 is kept at the same horizontal plane as the center of the lining measurement area, and uniform LED light sources are arranged on both sides of the high-speed camera 60 to reduce the influence of natural light and insufficient light on the recognition effect of the camera 60. When using the data, digital speckle devices need to be arranged both outside the outer pressure cylinder 13 and inside the inner pressure cylinder 14.

[0072] Then, calibrate the image. Completely display the calibration board 61 within the sight range of the camera 60, slowly move it in the measurement area, and uniformly move it to the four corners of the measurement area. Then turn on the high-speed camera 60 to take calibration photos. After collecting the experimental data, compare the images at different loading stages through vic-3D software, calculate the displacement changes of the characteristic points, and further calculate the strain field distribution based on the displacement field data. Visualize the displacement field and strain field data in the form of contour maps, nephograms, etc. to facilitate the analysis of the deformation and crack evolution process of the lining. The visualized data can intuitively display the stress concentration area, crack initiation position, and propagation path on the lining surface, providing an important basis for subsequent mechanical analysis.

[0073] For the above internal and external water pressure experiment and monitoring system of the hydraulic tunnel lining model and its usage method, since both the inner pressure cylinder 14 and the outer pressure cylinder 13 are made of transparent materials, they can not only withstand the water pressure in the experiment but also provide a clear observation field of view. At the same time, through the amplification effect of the water pressure, the cracks in the lining are more obvious, and the crack initiation and propagation behavior of the lining under the action of internal and external water pressure can be intuitively captured. The low-permeability and low-water-sensitivity lining similar material has the value of improving the waterproof performance and water-sensitivity resistance of the lining. This design enables researchers to intuitively capture the failure mechanism of the lining under complex water pressure, providing an important experimental means for in-depth study of the bearing and cracking behavior of the hydraulic tunnel lining 1.

[0074] The above embodiments are only used to illustrate the technical solutions of the present invention, not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A hydraulic tunnel lining model internal and external water pressure test and monitoring system, characterized in that: include: A model loading device, comprising a base, a cover plate, an external pressure cylinder and an internal pressure cylinder, wherein the external pressure cylinder and the internal pressure cylinder are coaxially arranged between the base and the cover plate, the external pressure cylinder and the internal pressure cylinder are made of transparent materials, a tunnel lining is provided between the internal pressure cylinder and the external pressure cylinder, the tunnel lining and the internal pressure cylinder form an internal water pressure chamber, the tunnel lining and the external pressure cylinder form an external water pressure chamber, and the cover plate is provided with a through hole for external equipment to enter the internal pressure cylinder; and The water pressure loading device includes an internal water pressure loading mechanism and an external water pressure loading mechanism. The internal water pressure loading mechanism is connected to the internal water pressure chamber and is used to provide water to the internal water pressure chamber; the external water pressure loading mechanism is connected to the external water pressure chamber and is used to provide water to the external water pressure chamber.

2. The hydraulic tunnel lining model internal and external water pressure test and monitoring system according to claim 1 is characterized in that: It also includes a lining production mold, which is provided with a molding cavity, the width of the molding cavity in the radial direction is greater than the width of the tunnel lining, the gap between the tunnel lining and the molding cavity is filled with paraffin powder, the tunnel lining is made of gypsum, and the lining production mold is heated to melt the paraffin so that the paraffin is immersed in the tunnel lining.

3. The hydraulic tunnel lining model internal and external water pressure test and monitoring system according to claim 2 is characterized in that: A heat insulation bracket is arranged in the molding cavity, and the tunnel lining is carried on the heat insulation bracket.

4. The hydraulic tunnel lining model internal and external water pressure test and monitoring system according to claim 1 is characterized in that: The surface of the tunnel lining is provided with image feature points, and the image feature points include at least one of digital speckle and grid lines.

5. The hydraulic tunnel lining model internal and external water pressure test and monitoring system according to claim 1 is characterized in that: The model loading device further comprises a first fixing block, the first fixing block is provided with a groove for the outer pressure cylinder to be inserted, and the first fixing block is mounted on the base; and / or The model loading device further comprises a second fixing block, the second fixing block is provided with a groove for inserting the inner pressure cylinder, and the second fixing block is mounted on the base.

6. The hydraulic tunnel lining model internal and external water pressure test and monitoring system according to claim 1 is characterized in that: The cover plate is provided with a first exhaust hole communicating with the internal water pressure chamber, and a detachable first sealing member is installed in the first exhaust hole; and / or The cover plate is provided with a second exhaust hole communicated with the external water pressure chamber, and a detachable second sealing member is installed in the second exhaust hole.

7. The hydraulic tunnel lining model internal and external water pressure test and monitoring system according to claim 1 is characterized in that: A first channel connected to the internal water pressure chamber is provided in the base, and the first channel passes through a side surface of the base and is connected to the internal water pressure loading mechanism; and / or A second channel communicating with the external water pressure chamber is provided in the base, and the second channel passes through the side surface of the base and communicates with the external water pressure loading mechanism.

8. The hydraulic tunnel lining model internal and external water pressure test and monitoring system according to claim 1 is characterized in that: The internal water pressure loading mechanism and the external water pressure loading mechanism have the same structure and both include a water adding bucket and a pressure volume controller. The water provided by the water adding bucket is transported to the corresponding water pressure chamber through the pressure volume controller.

9. A method for using the hydraulic tunnel lining model internal and external water pressure test and monitoring system according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: Providing a tunnel lining, and forming image feature points on a surface of the tunnel lining; Install the tunnel lining between the external pressure cylinder and the internal pressure cylinder, and then install a cover plate on the top of the external pressure cylinder, the tunnel lining and the internal pressure cylinder; Connecting the inner water pressure loading mechanism to the inner water pressure chamber, connecting the outer water pressure loading mechanism to the outer water pressure chamber, and selectively starting the inner water pressure loading mechanism and the outer water pressure loading mechanism to fill the inner water pressure chamber and / or the outer water pressure chamber with water to simulate the effect of water pressure on the tunnel lining; The data acquisition equipment collects the surface image information of the tunnel lining through the outer pressure cylinder and the inner pressure cylinder, and obtains the deformation and crack evolution process of the tunnel lining.

10. The method for using the hydraulic tunnel lining model internal and external water pressure test and monitoring system according to claim 9, characterized in that: The tunnel lining is made of gypsum, and after the step of forming image feature points on the surface of the tunnel lining, the step further includes: placing the tunnel lining with the image feature points attached thereto into a molding cavity of a lining preparation mold, and then adding paraffin powder to fill the gap between the tunnel lining and the molding cavity; The paraffin powder is heated by a heating wire in a lining preparation mold to melt and form a paraffin solution, so that the paraffin is fully immersed in the tunnel lining; After the paraffin is cooled and solidified, the tunnel lining is taken out from the molding cavity.

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