Tunnel mechanical property testing device

Abstract

The invention relates to the technical field of tunnel experiment devices, and discloses a tunnel mechanical property test device which comprises a lining structure connected to a base and further comprises a plurality of mechanical sensors, a counter-force supporting plate and a plurality of counter-force pressurizing assemblies evenly distributed in the lining structure. The counter-force supporting plate and the lining structure are the same in shape, the radius of the counter-force supporting plate is larger than that of the lining structure, the lining structure is sleeved with the counter-force supporting plate, the counter-force supporting plate and the lining structure are coaxial, the bottom of the counter-force supporting plate is fixedly connected with the base, and the multiple counter-force pressurization assemblies are connected between the counter-force supporting plate and the lining structure and used for applying pressure to the lining structure. The positions of the counterforce pressurizing assemblies can be adjusted at will. According to the invention, the complex stress state of the lining structure can be practically simulated.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel test devices, and in particular to a tunnel mechanical property test device. Background Art

[0002] Tunnels are structures in the strata, and the construction safety of tunnels has always been a top priority. Therefore, revealing the temporal and spatial characteristics of tunnel deformation is of great significance for scientifically evaluating tunnel stability and taking corresponding deformation control measures.

[0003] Since field tests are costly, time-consuming and laborious, and it is impossible to intuitively test the mechanical response of the tunnel under specific stress states or complex stress states, tunnel experimental devices or platforms are often used for simulation experiments. Existing tunnel experimental devices can usually simulate and restore the lining structure of a real arc-shaped concrete tunnel, and apply a reaction force to the lining structure to simulate the pressure of the tunnel rock on the lining structure, and set a mechanical sensor in the lining structure to detect the stress state of the lining structure after construction as the reaction force structure is pressed.

[0004] However, in reality, the contact between the tunnel rock and the tunnel lining structure is not dense, and there will be many holes, which leads to the difference between the stress when the rock and the lining structure are in contact and the stress when they are not in contact. The existing tunnel experimental platform often ignores the difference in stress, and it is difficult to simulate the stress state of the lining structure where there are holes in reality, nor can it simulate the stress state of the lining structure under the diversified position of multiple holes. Therefore, it is difficult to effectively reflect the real characteristics of the complex mechanical response. Summary of the invention

[0005] The invention provides a tunnel mechanical property test device which can effectively simulate the complex stress state of the lining structure.

[0006] The present invention provides a tunnel mechanical property testing device, comprising a lining structure, a plurality of mechanical sensors, a reaction force support plate, and a plurality of reaction force pressurizing components. The lining structure is connected to a base, the plurality of mechanical sensors are evenly distributed in the lining structure, the reaction force support plate has the same shape as the lining structure and a radius greater than the lining structure, the reaction force support plate is sleeved outside the lining structure and the two are coaxial, the bottom of the reaction force support plate is fixedly connected to the base, a plurality of reaction force pressurizing components are connected between the reaction force support plate and the lining structure to apply pressure to the lining structure, and the positions of the plurality of reaction force pressurizing components can be adjusted arbitrarily.

[0007] Preferably, a tunnel face is arranged at one end face of the lining structure, and the tunnel face is arranged within the inner contour section of the lining structure.

[0008] Preferably, a reaction force support seat is further provided between the lining structure and the base, and the reaction force support seat is used to support the lining structure to simulate the state in which the tunnel lining structure sinks after being squeezed in reality.

[0009] Preferably, a plurality of mechanical sensors are distributed on the inner arc surface, the middle part and the outer arc surface close to the reaction force support plate of the thickness of the lining structure, so as to realize uniform and accurate detection of the stress of the lining structure.

[0010] Preferably, the reaction force pressurizing assembly includes a first hydraulic cylinder, which includes a fixed part and a telescopic part, and both ends of the fixed part are connected to a curved abutment plate, which is tightly attached to the outer curved wall of the lining structure, and the abutment plate is detachably connected to the first hydraulic cylinder. By replacing abutments of different sizes and changing the size of the unloaded area, the mechanical state of the tunnel in the case of a cavity behind different lining structures can be simulated.

[0011] Preferably, the reaction force support seat includes a support seat body, a receiving groove is vertically opened in the middle of the support seat body, and a plurality of second hydraulic cylinders for lifting the lining structure are arranged at the bottom of the receiving groove. The bottom of the lining structure is placed in the receiving groove and connected to the telescopic part of the second hydraulic cylinder.

[0012] Preferably, the base is located in the middle of the lining structure and is fixedly connected to a slide rail along the axial extension direction of the lining structure. A slider is provided on the slide rail, and a monitor is provided above the slider to observe whether the lining structure is cracked or deformed under pressure.

[0013] Preferably, the tunnel face comprises rock mass or rock concrete.

[0014] Preferably, it also includes a steel frame arranged in the lining structure, and a plurality of displacement micrometers are arranged between the steel frame and the lining structure to monitor the typical cross-sectional displacement of the inner arc surface of the lining structure.

[0015] Preferably, the reaction force support plate is a steel plate.

[0016] Preferably, it also includes a dynamic data acquisition system for collecting and analyzing data from each mechanical sensor.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: through the mechanical sensors set up to monitor the tension and compression states of different parts of the lining structure under complex loading conditions in real time, basic data is provided for evaluating the stability of the tunnel and proposing safety measures, and the number of the sensors is multiple, so that the complex stress detection of the lining structure is more comprehensive and the acquired data is more accurate. At the same time, through the multiple reaction pressure components set up to partially contact and pressurize the lining structure to simulate the actual contact between the rock and the lining structure of the tunnel, and the uncontacted parts simulate the holes existing in reality, so as to achieve the realism of the experimental device. Specifically, the reaction pressure components are used to simulate complex loading states such as uniformly distributed force or stress concentration in the tunnel with the support of the reaction support plate, and the pressure is adjusted to simulate the surrounding rock pressure of the tunnel at different burial depths. The position of each reaction pressure component is adjustable by limiting the position, which can be used to simulate holes of different positions and sizes in reality, and effectively simulate the complex stress state of the lining structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the internal cross-sectional structure from a main perspective of a tunnel mechanical properties testing device provided by an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the internal cross-sectional structure of a tunnel mechanical properties testing device provided by an embodiment of the present invention from a side perspective;

[0020] Figure 3 A schematic diagram of the structure of a slide rail in a tunnel mechanical properties testing device provided by an embodiment of the present invention.

[0021] Description of reference numerals:

[0022] 1. Lining structure; 2. Base; 3. Mechanical sensor; 4. Reaction support plate; 5. Reaction pressure assembly; 51. First hydraulic cylinder; 52. Abutment plate; 6. Palm face; 7. Reaction support seat; 71. Support seat body; 711. Receiving groove; 72. Second hydraulic cylinder; 8. Slide rail; 81. Sliding block; 9. Monitor; 10. Dynamic data acquisition system; 11. Steel frame; 12. Displacement micrometer. DETAILED DESCRIPTION

[0023] A specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific implementation.

[0024] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the technical solutions of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0025] refer to Figure 1 and Figure 2 The present invention provides a tunnel mechanical property test device, comprising: a lining structure 1, a plurality of mechanical sensors 3, a reaction force support plate 4, and a plurality of reaction force pressurizing components 5. The lining structure 1 is connected to a base 2, and the plurality of mechanical sensors 3 are evenly distributed in the lining structure 1. The reaction force support plate 4 has the same shape as the lining structure 1 and a radius greater than that of the lining structure 1. The reaction force support plate 4 is sleeved outside the lining structure 1 and the two are coaxial. The bottom of the reaction force support plate 4 is fixedly connected to the base 2. The plurality of reaction force pressurizing components 5 are connected between the reaction force support plate 4 and the lining structure 1 to apply pressure to the lining structure 1. The positions of the plurality of reaction force pressurizing components 5 can be adjusted arbitrarily.

[0026] In the above embodiments, the mechanical sensors 3 are arranged to monitor the tension and compression states of different parts of the lining structure 1 under complex loading conditions in real time, so as to provide basic data for evaluating the stability of the tunnel and proposing safety measures. The number of the mechanical sensors 3 is multiple, so that the complex stress detection of the lining structure 1 is more comprehensive and the acquired data is more accurate. At the same time, the multiple reaction pressure components 5 are arranged to partially contact and pressurize the lining structure 1 to simulate the actual contact between the rock and the lining structure 1 of the tunnel, while the uncontacted parts simulate the holes existing in reality, so as to achieve the realism of the experimental device. Specifically, the reaction pressure component 5 is used to simulate the complex loading conditions such as uniformly distributed force or stress concentration of the tunnel with the support of the reaction support plate 4, and the pressure is adjusted to simulate the surrounding rock pressure of the tunnel at different burial depths. The position of each reaction pressure component 5 is adjustable, which can be used to simulate holes of different positions and sizes in reality, and effectively simulate the complex stress state of the lining structure 1.

[0027] Further, refer to Figure 1 and Figure 2 A tunnel face 6 is provided at one end face of the lining structure 1 , and the tunnel face 6 is provided within the inner contour section of the lining structure 1 .

[0028] In the above embodiments, the deformation characteristics of the tunnel at different distances from the tunnel face 6 can be obtained, and the spatiotemporal effect of the deformation of the tunnel structure under the constraint of the tunnel face 6 can be revealed, so as to guide the reasonable control of the tunnel excavation speed and the timing of lining construction in engineering practice and ensure the safety of tunnel construction; the deformations such as extrusion and sliding of the tunnel face 6 under different surrounding rock pressures can also be obtained, and the interaction relationship between the surrounding rock, the tunnel structure and the tunnel face 6 can be analyzed, so as to provide basic data for evaluating the stability of the tunnel and proposing deformation control measures.

[0029] Further, refer to Figure 1 and Figure 2 A reaction support seat 7 is also arranged between the lining structure 1 and the base 2. The reaction support seat 7 is used to support the lining structure 1 to simulate the state in reality that the arch foot of the lining structure 1 sinks due to insufficient foundation strength after the tunnel lining structure 1 is squeezed. The reaction support seat 7 includes a support seat body 71. A receiving groove 711 is vertically opened in the middle of the support seat body 71. A plurality of second hydraulic cylinders 72 for lifting the lining structure 1 are arranged at the bottom of the receiving groove 711. The bottom of the lining structure 1 is placed in the receiving groove 711 and is connected to the telescopic part of the second hydraulic cylinder 72.

[0030] In the above embodiments, by adjusting the reaction force provided by the actuator on the reaction base 2, the mechanical characteristics of the tunnel structure under boundary conditions such as the arch foot sinking or the arch foot being hard and not deformed can be simulated. By reading the hydraulic cylinder pressure of the base 2 and the lining structure 1 combined with the displacement monitoring value, the arch foot pressure and stability state of the tunnel under the overlying pressure can be understood. By reducing the hydraulic cylinder pressure of the base 2, the mechanical response of the lining structure 1 when the foundation strength is insufficient and the arch foot sinks can be simulated, and the tunnel instability mode and failure form caused by the insufficient arch foot strength can be obtained.

[0031] Further, refer to Figure 1 and Figure 2 A plurality of mechanical sensors 3 are distributed on the inner arc surface, the middle part and the outer arc surface close to the reaction support plate 4 of the thickness of the lining structure 1 to achieve uniform and accurate detection of the stress of the lining structure 1 .

[0032] In the above embodiments, the mechanical sensor 3 is set to monitor the deformation and tension and compression state of the tunnel structure in different parts of the tunnel under complex load conditions in real time, providing basic data for evaluating the stability of the tunnel and proposing safety measures. The displacement meter adopts the JC-WY-20 inductive frequency modulation sensor, which measures the physical quantity by causing the displacement of the built-in magnetic core to cause the inductance to change and the output frequency to change. It has the characteristics of strong anti-interference ability, high precision, good stability, and large range, and is suitable for testing the deformation and failure behavior of the target body in this system. The pressure gauge adopts the JC-TY-40 vibrating string sensor, which uses the relationship between the pressure on the steel string and the natural frequency to measure the physical quantity, can compensate for temperature stress, etc., has the characteristics of high precision, stable performance, strong ability to adapt to the environment, and is suitable for tunnel mechanics monitoring.

[0033] Further, refer to Figure 1 It also includes a steel frame 11 arranged in the lining structure 1 , and a plurality of displacement micrometers 12 are arranged between the steel frame 11 and the lining structure 1 to monitor the typical cross-sectional displacement of the inner arc surface of the lining structure 1 .

[0034] Further, refer to Figure 1 and Figure 2 The reaction force pressurizing component 5 includes a first hydraulic cylinder 51, and the first hydraulic cylinder 51 includes a fixed part and a telescopic part. The ends of the fixed part are connected with arc-surface abutment plates 52, and the abutment plates 52 are tightly attached to the outer arc wall of the lining structure 1. The abutment plates 52 and the first hydraulic cylinder 51 are detachably connected. By replacing abutment plates 52 of different sizes, the size of the unloaded area can be changed to simulate the mechanical state of the tunnel under the condition of the hollow behind different lining structures 1. Specifically, the position of the first hydraulic cylinder 51 can be changed. After the change, the abutment plates 52 can be fixed by bolts, or they can be moved by means of slide grooves and the like and the position can be limited by conventional limiting methods. For example, the moved reaction force pressurizing component 5 is connected and limited to the slide groove socket by means of a latch.

[0035] In the above embodiments, by changing the position of the abutment plate 52, the mechanical characteristics and deformation failure behavior of the tunnel under the condition of cavities in different parts such as the arch crown, arch waist, arch foot, etc. can be simulated, and the most unfavorable cavity position affecting the stability of the tunnel can be obtained; by changing the area of ​​the abutment plate 52 to change the non-loaded area, the mechanical characteristics and deformation failure behavior of the tunnel under different cavity sizes can be simulated, and the critical cavity area that has an adverse effect on the stability of the tunnel under different surrounding rock pressure conditions can be obtained. The above research work has important reference and guiding significance for the treatment of cavities behind the on-site tunnel lining and the control of tunnel deformation. .

[0036] Further, refer to Figure 1 , Figure 2 and Figure 3The base 2 is located in the middle of the lining structure 1 and is fixedly connected with a slide rail 8 along the axial extension direction of the lining structure 1. A slider 81 is arranged on the slide rail 8. A monitor 9 for observing whether the lining structure 1 is cracked or deformed under the pressurized state is arranged above the slider 81. Specifically, the monitor 9 is preferably a multi-angle M120 high-speed camera with a frame rate of more than 2000fps, which is suitable for non-contact three-dimensional high-speed measurement of structural cracks, etc. The monitor 9 can also carry a laser three-dimensional profile measuring instrument.

[0037] A laser three-dimensional profile tester may also be provided above the slider 81 to observe whether the inner profile of the lining structure 1 changes under the pressurized state, so as to more realistically reflect the actual mechanical properties of the tunnel.

[0038] In the above embodiments, the monitor 9 is fixed to the base of the slider 81 through the positioning hole. The camera system on the slide rail 8 can obtain the deformation, cracking and damage of the tunnel structure under complex stress conditions in real time, providing basic data for obtaining the ultimate bearing capacity of the tunnel and evaluating the stability of the tunnel.

[0039] Further, refer to Figure 2 , the tunnel face 6 includes rock and soil or stone concrete.

[0040] Further, refer to Figure 2 , the reaction support plate 4 is a steel plate.

[0041] In the above embodiments, the steel plate thickness of the reaction support plate 4 is 8-10 mm to ensure that the reaction system has sufficient rigidity. On the basis of ensuring the reaction rigidity and strength, holes can be opened as needed, such as the specific fixed positioning of the first hydraulic cylinder 51.

[0042] Further, refer to Figure 1 , and also includes a BL800-D multi-channel dynamic data acquisition system 10 for collecting and analyzing data from each mechanical sensor 3.

[0043] In the above embodiments, the BL800-D multi-channel dynamic data acquisition system 10 is used, the displacement meter adopts the JC-WY-20 inductive frequency modulation sensor, and the pressure gauge adopts the JC-TY-40 vibrating string sensor, which can compensate for temperature stress, etc., and has the characteristics of high precision, stable performance, strong adaptability to the environment, etc., and has good applicability for tunnel mechanics monitoring. The stability of the tunnel is judged by combining the stress and displacement monitoring results. If the displacement time-history curve changes suddenly or produces rheology, it indicates that the material produces plastic flow or slip, indicating that the structure is about to be destroyed. If the monitored stress reaches the compressive or tensile strength of the material, it indicates that the structure is about to be destroyed.

[0044] Specifically, the lining structure 1 can be cast or 3D printed using barite powder, gypsum, quartz sand, gelling agent, water, iron powder or ceramic particles according to a certain mix ratio to simulate the actual tunnel support structure;

[0045] The slide rail 8 is provided with multiple lighting systems to provide the lighting source required for video recording during the test. The slider 81 is designed with multiple bolt holes in the longitudinal direction to flexibly fix the monitor 9. The slide rail 8 is used to fix the lighting system to prevent the equipment from vibrating during the test and affecting the test and monitoring effect.

[0046] In summary, this experimental device solves the problem of all-round and multi-angle acquisition of tunnel mechanical response under the combined action of complex stress states and complex boundary conditions. It can deeply reveal the complex stress state of the tunnel, provide support for the evaluation of tunnel structure stability and propose effective deformation control measures.

[0047] The above disclosures are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A tunnel mechanical properties test device, characterized in that: include: A lining structure (1) connected to a base (2); A plurality of mechanical sensors (3) are evenly distributed in the lining structure (1); A reaction force support plate (4) having the same shape as the lining structure (1) and a radius greater than that of the lining structure (1); the reaction force support plate (4) is sleeved outside the lining structure (1) and the two are coaxial; and the bottom of the reaction force support plate (4) is fixedly connected to the base (2); A plurality of reaction force pressurizing components (5) are connected between the reaction force support plate (4) and the lining structure (1) to apply pressure to the lining structure (1); the positions of the plurality of reaction force pressurizing components (5) can be adjusted arbitrarily.

2. A tunnel mechanical properties testing device as claimed in claim 1, characterized in that: A working face (6) is arranged at one end face of the lining structure (1), and the working face (6) is arranged within the inner contour section of the lining structure (1).

3. A tunnel mechanical properties testing device as claimed in claim 2, characterized in that: A reaction force support seat (7) is also provided between the lining structure (1) and the base (2), and the reaction force support seat (7) is used to support the lining structure (1) to simulate the state in which the tunnel lining structure (1) sinks after being squeezed in reality.

4. A tunnel mechanical properties testing device as claimed in claim 1, characterized in that: The plurality of mechanical sensors (3) are distributed on the inner curved surface, the middle portion and the outer curved surface close to the reaction force support plate (4) of the thickness of the lining structure (1), so as to achieve uniform and accurate detection of the stress of the lining structure (1).

5. A tunnel mechanical properties testing device as claimed in claim 4, characterized in that: The reaction force pressurizing assembly (5) comprises a first hydraulic cylinder (51), the first hydraulic cylinder (51) comprises a fixed portion and a telescopic portion, the ends of the fixed portion are connected to arc-surface abutment plates (52), the abutment plates (52) are in close contact with the outer arc wall of the lining structure (1), the abutment plates (52) and the first hydraulic cylinder (51) are detachably connected, and by replacing abutment plates (52) of different sizes and changing the size of the unloaded area, the mechanical state of the tunnel under different conditions of hollow spaces behind the lining structures (1) can be simulated.

6. A tunnel mechanical properties testing device as claimed in claim 3, characterized in that: The reaction force support seat (7) comprises a support seat body (71), a receiving groove (711) is vertically provided in the middle of the support seat body (71), a plurality of second hydraulic cylinders (72) for lifting and lowering the lining structure (1) are provided at the bottom of the receiving groove (711), and the bottom of the lining structure (1) is placed in the receiving groove (711) and connected to the telescopic part of the second hydraulic cylinder (72).

7. A tunnel mechanical properties testing device as claimed in claim 1, characterized in that: The base (2) is located in the middle of the lining structure (1) and is fixedly connected to a slide rail (8) along the axial extension direction of the lining structure (1); a slider (81) is provided on the slide rail (8); and a monitor (9) for observing whether the lining structure (1) is cracked or deformed under a pressurized state is provided above the slider (81).

8. A tunnel mechanical properties testing device as claimed in claim 2, characterized in that: The tunnel face (6) comprises rock and soil or stone concrete.

9. A tunnel mechanical properties testing device as claimed in claim 5, characterized in that: It also includes a steel frame (11) arranged in the lining structure (1), and a plurality of displacement micrometers (12) are arranged between the steel frame (11) and the lining structure (1) to monitor the typical cross-sectional displacement of the inner arc surface of the lining structure (1).

10. A tunnel mechanical properties testing device as claimed in claim 1, characterized in that: It also includes a dynamic data acquisition system (10) for collecting and analyzing data from each mechanical sensor (3).

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