Testing device for similar model of roadway grouting pressure-bearing arch

Abstract

The utility model discloses a testing device for a tunnel grouting pressure-bearing arch similar model, which relates to the technical field of testing devices and comprises the tunnel grouting pressure-bearing arch similar model arranged in the central area of a fixed outer frame, and the tunnel grouting pressure-bearing arch similar model is manufactured by pouring a pressure-bearing arch manufacturing mold. A center hole is formed in the center area of the tunnel grouting pressure-bearing arch similar model, and a plurality of displacement measuring points are arranged on the inner wall of the center hole; a plurality of servo hydraulic cylinders are evenly distributed on the periphery of the roadway grouting pressure-bearing arch similar model, the servo hydraulic cylinders are all fixedly installed in the rotatable inner frame, and the rotatable inner frame is rotationally connected with the fixed outer frame through a connecting bearing. According to the utility model, the mechanical property analysis of the pressure-bearing arch under the laboratory scale is realized, the angle of the model can be randomly adjusted in the manufacturing test process, the demolding of the model is facilitated, more complex resultant force can be applied in the model test process, and the test range is wider.

Description

Technical Field

[0001] The utility model relates to the technical field of test devices, in particular to a test device for a similar model of a tunnel grouting pressure-bearing arch. Background Art

[0002] At present, the tunnel surrounding rock grouting technology is developing towards deeper, longer and faster construction, and its importance is increasing, and it has gradually become one of the indispensable core construction links of poor geological tunnels. The grouting effect and slurry diffusion law are often difficult to see intuitively in engineering practice or theoretical analysis. Numerical simulation often requires certain construction and simplification of engineering geological conditions, slurry diffusion methods, etc., while model tests can consider the actual situation as much as possible and can conduct a large number of tests.

[0003] In order to solve the problems of poor simulation effect and poor adaptability of existing grouting test devices, Chinese Patent Publication No. CN116046548A discloses a new type of tunnel grouting reinforcement similar model test device and method, which effectively simulates the actual tunnel and surrounding rock by setting up a tunnel module, a surrounding rock module and a loading system, and realizes a simple and effective simulation of the grouting reinforcement model. Although the device can achieve the simulation effect of the grouting test device well, since the grouting is still carried out in the surrounding rock composed of similar materials, it is still impossible to conduct an intuitive study on the grouting pressure arch, and the slurry injection in the small-scale similar material cannot effectively simulate the large-scale grouting pressure arch in the real situation. Therefore, the test results of the device can only be used for the macroscopic verification of the overall support strength of the grouting tunnel, and cannot realize the independent and accurate numerical research function of the grouting pressure arch.

[0004] Although the existing grouting model test device can simulate grouting under tunnel excavation conditions, the grouting pressure arch is located in the surrounding rock model, which cannot be observed intuitively, and it is even more impossible to conduct a detailed analysis of the deformation and stress of the pressure arch according to the needs. The obstacles of experimental simulation on the laboratory scale have led to the inability to continue to carry out more detailed research and analysis on the pressure arch in the surrounding rock, hindering the further development of the underground engineering support grouting support system. Therefore, it is necessary to design a new device that can maximize the simulation of the pressure arch formed by grouting in the surrounding rock of the deep tunnel, and use it to study its bearing principle and understand its action mechanism more intuitively. By accurately monitoring the deformation of the pressure arch manufacturing mold, the purpose of analyzing the mechanical properties of the pressure arch on the laboratory scale can be achieved. Utility Model Content

[0005] The main purpose of the utility model is to provide a test device for a similar model of a tunnel grouting pressure-bearing arch, which can effectively solve the problems in the background technology.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A test device for a tunnel grouting pressure-bearing arch similarity model comprises a tunnel grouting pressure-bearing arch similarity model arranged in the central area of ​​a fixed outer frame, the tunnel grouting pressure-bearing arch similarity model is cast by a pressure-bearing arch manufacturing mold, a central hole is provided in the central area of ​​the tunnel grouting pressure-bearing arch similarity model, and a plurality of displacement measuring points are arranged on the inner wall of the central hole; a plurality of servo hydraulic cylinders are evenly distributed around the tunnel grouting pressure-bearing arch similarity model, the plurality of servo hydraulic cylinders are fixedly installed inside a rotatable inner frame, and the rotatable inner frame is rotatably connected to the fixed outer frame through a connecting bearing.

[0008] Preferably, the pressure arch manufacturing mold includes a mold rear cover plate, a mold center cylinder is installed in the central area of ​​one end of the mold rear cover plate, and a mold side cover plate with a ring structure is also installed, and a mold front cover plate is installed at the other end of the mold side cover plate. The mold rear cover plate, the mold center cylinder, the mold side cover plate and the mold front cover plate together form a cavity that matches the model shape similar to the tunnel grouting pressure arch.

[0009] Preferably, the mold side cover plate is composed of several arc-shaped plates spliced ​​end to end, and the arc-shaped plates are connected in a detachable manner.

[0010] Preferably, the front cover plate of the mold is made by splicing a plurality of strip plates, and each strip plate can be individually connected to the side cover plate of the mold.

[0011] Preferably, the mold rear cover plate, the mold center cylinder, the mold side cover plates and the mold front cover plate are all connected in a disassembly manner.

[0012] Preferably, an arc-shaped hydraulic cushion matching the model shape of the tunnel grouting pressure-bearing arch is installed at the end of the piston rod of the servo hydraulic cylinder.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] The manufacturing mold and test device of the grouting pressure-bearing arch are combined into one, which realizes the integrated research of the grouting pressure-bearing arch in the tunnel, eliminates the transportation operation after the model is made, saves manpower and avoids the adverse effects and errors caused by model disturbance.

[0015] The modular design of the pressure arch manufacturing mold makes the size of the pressure arch model produced by this device adjustable and easier to disassemble and assemble. The shape and various parameters of the pressure arch are determined in the early stage of production. The overall specifications of the pressure arch can be adjusted by adjusting the curved plates and the central cylinder around it. This makes the model test device suitable for the analysis of the mechanical properties of pressure arches of most shapes, greatly improving the applicability of the device test and its fit with actual working conditions.

[0016] The frame is divided into two parts, a rotatable inner frame and a fixed outer frame, by connecting bearings. The existence of the rotatable inner frame allows the model angle to be arbitrarily adjusted during the manufacturing test, which not only facilitates the demoulding of the model but also allows more complex combined forces to be applied during the model test, making the test range wider. The design of the rotatable inner frame not only improves the applicability of the device, but also provides a broader operating space for early model making and later force analysis.

[0017] The central cylindrical design of the mold reserves sufficient control space for the center of the pressure arch, and the internal operating space of the test device is relatively ample. Combined with the adjustable arc-shaped hydraulic pad, it is compatible with various specifications of grouting pressure arch models.

[0018] The pressure arch manufacturing molds are completely dismantled during the test and do not participate in any stress process in the test. The exposed tunnel grouting pressure arch similar surface can be used for other test monitoring such as acoustic emission and digital speckle to obtain more comprehensive experimental data. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the entire test device proposed in this embodiment;

[0020] Figure 2 It is a structural schematic diagram of a pressure-bearing arch manufacturing mold of a similar model of a tunnel grouting pressure-bearing arch in this embodiment.

[0021] In the figure: 1. Fixed outer frame; 2. Connecting bearing; 3. Rotatable inner frame; 4. Servo hydraulic cylinder; 5. Arc hydraulic pad; 6. Similar model of tunnel grouting pressure arch; 7. Center hole; 8. Displacement measuring point; 9. Mold rear cover plate; 10. Mold center cylinder; 11. Mold side cover plate; 12. Mold front cover plate. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0023] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing 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 cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] like Figure 1-Figure 2 As shown, a test device for a tunnel grouting pressure-bearing arch similar model comprises a tunnel grouting pressure-bearing arch similar model 6 arranged in the central area of ​​a fixed outer frame 1, the tunnel grouting pressure-bearing arch similar model 6 is cast by a pressure-bearing arch manufacturing mold, a central hole 7 is arranged in the central area of ​​the tunnel grouting pressure-bearing arch similar model 6, and a plurality of displacement measuring points 8 are arranged on the inner wall of the central hole 7. In this embodiment, the tunnel grouting pressure-bearing arch similar model 6 and the central hole 7 are both circular structures, four displacement measuring points 8 are arranged, and the interval between two adjacent displacement measuring points 8 is 45°. The displacement measuring points 8 are realized by an infrared ranging method and are used to monitor the tunnel grouting pressure-bearing arch during the experiment. Internal deformation of the arch similarity model 6; Several servo hydraulic cylinders 4 are evenly distributed around the tunnel grouting pressure arch similarity model 6. In this embodiment, four servo hydraulic cylinders 4 are provided. The servo hydraulic cylinders 4 are used to apply pressure on the four sides of the tunnel grouting pressure arch similarity model 6 to simulate the stress state under different geological stress scenarios. The four servo hydraulic cylinders 4 are all fixedly installed inside the rotatable inner frame 3. The rotatable inner frame 3 is rotatably connected to the fixed outer frame 1 through the connecting bearing 2. The rotatable inner frame 3 is designed as a circular ring structure, that is, the rotatable inner frame 3 can rotate around its center of circle, which is convenient for the later removal of the mold and the removal of the model after the test.

[0026] On the basis of the above scheme, in order to realize the centralized control of the test device, the rotatable inner frame 3 is driven to rotate by a servo motor, and the servo motor, displacement measuring point 8 and servo hydraulic cylinder 4 are all electrically connected to the control center, and controlled, monitored and processed by a high-performance computer in the control center, including the oil pressure control of the servo hydraulic cylinder 4, the angle control of the rotatable inner frame 3, the monitoring of the displacement measuring point 8, etc., integrating the functions of adjustment, pressurization, monitoring, calculation, etc. It should be noted that the relevant equipment adopts the currently known equipment, and since it is not the focus of the technical solution to be protected by this application, it will not be described in detail.

[0027] In order to ensure that the servo hydraulic cylinder 4 evenly applies pressure to the similar model 6 of the tunnel grouting pressure arch, in the utility model, the end of the piston rod of the servo hydraulic cylinder 4 is equipped with an arc-shaped hydraulic pad 5 that matches the shape of the similar model 6 of the tunnel grouting pressure arch. The arc shape of the arc-shaped hydraulic pad 5 can well support the circular similar model 6 of the tunnel grouting pressure arch and evenly transfer the force to the model. On the other hand, the size of the arc-shaped hydraulic pad 5 can be adjusted according to different test schemes, and its curvature or even shape can be changed. In combination with different models of model pressure arch manufacturing molds, the test device of the pressure arch manufacturing mold can manufacture and test similar models of various materials, shapes, and sizes, not limited to similar models with circular, elliptical, and square cross-sections.

[0028] In addition, the pressure arch manufacturing mold includes a mold rear cover plate 9, a mold center cylinder 10 is installed in the central area of ​​one end of the mold rear cover plate 9, and a mold side cover plate 11 with a ring structure is also installed, and a mold front cover plate 12 is installed at the other end of the mold side cover plate 11. The mold rear cover plate 9, the mold center cylinder 10, the mold side cover plate 11 and the mold front cover plate 12 together form a cavity that matches the shape of the model 6 similar to the tunnel grouting pressure arch; the mold side cover plate 11 is composed of several arc plates spliced ​​end to end, and the arc plates are connected in a detachable manner; the mold front cover plate 12 is made of several strip plates spliced ​​together, and each strip plate can be individually connected to the mold side cover plate 11. In this embodiment, the mold center cylinder 10 is fixed on the mold rear cover 9, and its size can be changed according to the requirements of the model; the mold side cover 11 is composed of four arc-shaped plates spliced ​​together, and connection holes are opened at both ends of the arc-shaped plates. Any two arc-shaped plates can be connected and fixed using screws. After the four arc-shaped plates are connected, a complete circular space is formed, and when the screws are removed, the arc-shaped plate can be pulled out radially, which is convenient for the removal of the mold and the removal of the model is more convenient; the mold rear cover 9 is a round cake-shaped whole, and a circle of connection holes is opened on the outer edge for fixing four arc-shaped plates, and a circle of connection holes is opened in the center for fixing the mold center cylinder 10. The surrounding radius of the connection hole is small, and it can be adapted to install mold center cylinders 10 of various sizes; connection holes are opened on the side of the mold front cover 12 and the outer circle of the mold rear cover 9 for connection and fixation; the mold front cover 12 is a circular cover plate horizontally divided into several sections, each section can be fixed on the arc plate separately, which is convenient for the production and shaping of the model in the mold.

[0029] Among them, the center cylinder 10 of the mold can be disassembled and replaced with different sizes, shapes or eccentric inner diameters according to different test plans. In combination with different sizes of the model periphery, it is possible to customize and manufacture pressure arch similar material models with rich and diverse sizes and shapes, or even tunnel surrounding rock similar models.

[0030] The mold rear cover plate 9 and the mold front cover plate 12 can be completely removed, and the front and back of the model can be completely exposed. In conjunction with other monitoring instruments, data acquisition for a series of auxiliary tests such as digital speckle, acoustic emission, and stress box can be performed.

[0031] The utility model also proposes a test method for a similar model of a tunnel grouting pressure-bearing arch, comprising the following construction steps:

[0032] S1. Correctly place the pressure arch manufacturing mold inside the test device, and apply a little pressure so that the arc-shaped hydraulic pad 5 presses the pressure arch manufacturing mold, and finally remove the front cover plate 12 of the mold;

[0033] S2. Based on the model similarity ratio, similar materials of grouting surrounding rocks under different stratum lithology are configured, and similar materials of pressure-bearing arch are added to the pressure-bearing arch manufacturing mold, so that the model has similar physical and mechanical properties to the rock mass under real geological conditions;

[0034] S3, adding materials layer by layer from the bottom to the top to make a similar model 6 of the tunnel grouting pressure-bearing arch and pressing it tightly, and installing the front cover plate 12 of the mold in sequence until it is completely sealed;

[0035] S4, when the pressure arch manufacturing mold becomes stable, the tunnel grouting pressure arch similar model 6 is maintained;

[0036] S5. When the pressure-bearing arch manufacturing mold meets the test requirements, the mold can be dismantled. First, the pressure of the servo hydraulic cylinder 4 is released, and then the mold front cover plate 12, the mold side cover plate 11, and the mold rear cover plate 9 are dismantled until the pressure-bearing arch manufacturing mold is completely dismantled on the test device and re-tested and fixed;

[0037] S6. Test the pressure arch manufacturing mold. Use the control center to manipulate the servo hydraulic cylinder 4 in different directions to apply different pressures to conduct tests, compare and analyze the stress and deformation of the model, and realize data collection and analysis of the pressure arch action mechanism at the laboratory scale.

[0038] Among them, in step S6, the pressure arch manufacturing mold is tested. First, the control center can be used to control four servo hydraulic cylinders 4 to apply original ground stress to the pressure arch manufacturing mold, so that the stress state of the model is as close as possible to the pressure arch in the actual situation. Then, the angle of the pressure arch can be rotated and adjusted according to the specific experimental plan, and each servo hydraulic cylinder 4 can be controlled to apply force in different directions to the similar model 6 of the tunnel grouting pressure arch, finally achieving the experimental purposes of observing the deformation and failure characteristics of the model, collecting the stress change curve of the model, and summarizing the stress action mechanism of the pressure arch.

[0039] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A test device for a tunnel grouting pressure-bearing arch similarity model, comprising a tunnel grouting pressure-bearing arch similarity model (6) arranged in the central area of ​​a fixed outer frame (1), characterized in that: The tunnel grouting pressure-bearing arch similar model (6) is cast by a pressure-bearing arch manufacturing mold. A center hole (7) is arranged in the central area of ​​the tunnel grouting pressure-bearing arch similar model (6), and a plurality of displacement measuring points (8) are arranged on the inner wall of the center hole (7). A plurality of servo hydraulic cylinders (4) are evenly distributed around the tunnel grouting pressure-bearing arch similar model (6), and the plurality of servo hydraulic cylinders (4) are fixedly installed inside a rotatable inner frame (3). The rotatable inner frame (3) is rotatably connected to a fixed outer frame (1) via a connecting bearing (2).

2. The test device of a similar model of a tunnel grouting pressure arch according to claim 1, characterized in that: The pressure arch manufacturing mold comprises a mold rear cover plate (9), a mold center cylinder (10) is installed in the central area of ​​one end of the mold rear cover plate (9), and a mold side cover plate (11) with a ring structure is also installed, and a mold front cover plate (12) is installed at the other end of the mold side cover plate (11), and the mold rear cover plate (9), the mold center cylinder (10), the mold side cover plate (11) and the mold front cover plate (12) together enclose a cavity that matches the shape of a similar model (6) of a tunnel grouting pressure arch.

3. The test device of the similar model of tunnel grouting pressure arch according to claim 2 is characterized in that: The mold side cover plate (11) is composed of a plurality of arc-shaped plates spliced ​​end to end, and the arc-shaped plates are connected in a detachable manner.

4. The test device for a similar model of a tunnel grouting pressure arch according to claim 2, characterized in that: The mold front cover plate (12) is made by splicing a plurality of strip plates, and each strip plate can be connected to the mold side cover plate (11) individually.

5. The test device of the similar model of tunnel grouting pressure arch according to claim 2, characterized in that: The mold rear cover plate (9), the mold center cylinder (10), the mold side cover plate (11) and the mold front cover plate (12) are all connected in a disassembly manner.

6. The test device of a similar model of a tunnel grouting pressure arch according to claim 1, characterized in that: The piston rod end of the servo hydraulic cylinder (4) is provided with an arc-shaped hydraulic cushion (5) matching the shape of a similar model (6) of a tunnel grouting pressure-bearing arch.

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