A force gauge for rapid stress assessment of tunnel support structures

Abstract

This utility model relates to the field of tunnel engineering construction monitoring technology, and discloses a force gauge for rapid stress assessment of tunnel support structures. It includes a base plate, a support column fixedly connected to the top of the base plate, an mounting sleeve fixedly connected to the outer wall of the support column by bolts, a force gauge fixedly connected to the outer wall of the mounting sleeve, a sliding column slidably connected inside the base plate, multiple fixing holes on the outer wall of the sliding column, a top plate fixedly connected to the top of the sliding column, a fixing assembly on the outer wall of the support column, a stress sensor mounted on the top of the top plate, a connecting column fixedly connected to the top of the stress sensor, and a leveling assembly on the top of the connecting column. In this utility model, the overall height can be conveniently adjusted through the cooperation of the base plate, the sliding column, and the fixing assembly. The sliding column can slide vertically within the base plate, locked in place by the engagement of a fixing pin with the multiple fixing holes on the outer wall of the sliding column.

Description

Technical Field

[0001] This utility model relates to the field of tunnel engineering construction monitoring technology, and in particular to a force gauge for rapid stress assessment of tunnel support structures. Background Technology

[0002] During tunnel construction and operation, the stress state of the tunnel support structure (such as steel supports, anchor bolts, and shotcrete layers) directly affects the tunnel's construction safety and long-term stability. To prevent collapses and deformations due to overload, it is necessary to periodically or in real-time assess the stress state of the support structure using force gauges. This process is typically used for support effectiveness testing during tunnel construction and safety hazard identification during operation, making it a crucial link in ensuring tunnel safety. The core function of the force gauge is to accurately collect force or stress data transmitted by the support structure, providing data support for engineers to assess the stability of the support structure and develop reinforcement or maintenance plans.

[0003] Existing force gauges mostly have a fixed plane as the contact surface with the support structure. If the surface of the support structure is uneven, localized poor contact or excessive compression can easily occur, making it difficult to evenly transmit force to the internal sensor and causing deviations in the detection data. Although some devices are equipped with simple leveling components, they can only achieve fine-tuning of the angle in one direction, which is insufficient to cope with the complex unevenness of the support structure surface. Therefore, a force gauge for rapid stress assessment of tunnel support structures is proposed. Utility Model Content

[0004] To overcome the above deficiencies, this utility model provides a force gauge for rapid stress assessment of tunnel support structures, aiming to solve the problem in the prior art where the surface of the support structure is uneven, which easily leads to localized poor contact or excessive compression, making it difficult to uniformly transmit force to the internal sensors.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a force gauge for rapid stress assessment of tunnel support structure, comprising a base plate, a support column fixedly connected to the top of the base plate, an installation sleeve fixedly connected to the outer wall of the support column by bolts, a force gauge fixedly connected to the outer wall of the installation sleeve, a sliding column slidably connected inside the base plate, multiple fixing holes opened on the outer wall of the sliding column, a top plate fixedly connected to the top of the sliding column, a fixing assembly provided on the outer wall of the support column, a stress sensor installed on the top of the top plate, a connecting column fixedly connected to the top of the stress sensor, and a leveling assembly provided on the top of the connecting column; The leveling assembly includes a universal ball joint, the bottom of which is fixedly connected to the top of the connecting column. Three connecting rods are rotatably connected to the outer wall of the universal ball joint. The end of each connecting rod away from the universal ball joint is rotatably connected to an outer rod via a damping shaft. A limit plate is slidably connected to the inner wall of the outer rod. A pressure spring is fixedly connected to one side of the limit plate, and an inner rod is fixedly connected to the other side of the limit plate. An anti-slip rubber pad is fixedly connected to the side of the inner rod away from the limit plate. A locking assembly is provided on the outer wall of the outer rod.

[0006] Preferably, the locking assembly includes a stop rod, the top of which is fixedly connected to the top of the outer rod, the outer wall of which has a threaded groove, and the outer wall of which is threadedly connected to a threaded sleeve.

[0007] Preferably, the fixing component includes a fixing pin, the outer wall of which is slidably connected to the inner wall of the support column, a locking spring is inserted into the outer wall of the fixing pin, and the fixing pin passes through the support column and engages with the fixing hole.

[0008] Preferably, the force gauge and the stress sensor are electrically connected via wires.

[0009] Preferably, the end of the pressure spring away from the limiting plate is fixedly connected to the inner wall of the outer rod.

[0010] Preferably, the top of the abutment is slanted, and the inner wall of the abutment and the outer wall of the inner rod abut against each other.

[0011] Preferably, the top of the threaded sleeve is narrower at the top and wider at the bottom, and the inner wall of the threaded sleeve abuts against the outer wall of the abutment.

[0012] This utility model has the following beneficial effects: 1. In this utility model, the overall height can be conveniently adjusted through the cooperation of the base plate, sliding column, and fixing components. The sliding column can slide vertically within the base plate, and is locked in place by the engagement of a fixing pin with multiple fixing holes on the outer wall of the sliding column. This allows for precise adjustment of the force measuring device height according to the actual height of the tunnel support structure, enabling force assessment of support structures at different heights.

[0013] 2. In this utility model, multi-directional rotation can be achieved through the universal ball joint, providing a flexible adjustment basis for the three distributed connecting rods. In conjunction with the damping shaft between the connecting rod and the outer rod, it can adapt to the unevenness of the support structure surface. At the same time, the pressure spring inside the outer rod, the limiting plate, and the inner rod form an adaptive adjustment system. The dual leveling mechanism effectively eliminates the influence of the unevenness of the support structure surface on the force transmission, ensuring that the force can be evenly transmitted to the stress sensor, and significantly improving the accuracy and reliability of the force assessment data. Attached Figure Description

[0014] Figure 1 This is a first-view perspective perspective view of a force gauge for rapid stress assessment of tunnel support structure proposed in this utility model. Figure 2 This is a second-view perspective perspective view of a force gauge for rapid stress assessment of tunnel support structures proposed in this utility model. Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 This is a cross-sectional view of the outer rod of a force gauge for rapid stress assessment of tunnel support structures proposed in this utility model. Figure 5 for Figure 4 Enlarged view of section B in the middle.

[0015] Legend: 1. Base plate; 2. Support column; 3. Mounting sleeve; 4. Force gauge; 5. Sliding column; 6. Fixing hole; 7. Top plate; 8. Fixing pin; 9. Locking spring; 10. Stress sensor; 11. Connecting column; 12. Universal ball joint; 13. Connecting rod; 14. Outer rod; 15. Limiting plate; 16. Compression spring; 17. Inner rod; 18. Anti-slip rubber pad; 19. Abutment rod; 20. Threaded groove; 21. Threaded sleeve. Detailed Implementation

[0016] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples.

[0017] Reference Figures 1-3This utility model provides an embodiment of a force gauge for rapid stress assessment of tunnel support structures, comprising a base plate 1. The base plate 1 provides a stable mounting foundation for the entire force gauge 4, ensuring that the force gauge 4 remains stable during the stress assessment of the tunnel support structure. A support column 2 is fixedly connected to the top of the base plate 1, serving as a support connecting the base plate 1 to subsequent installation components and providing support for the vertical structure of the entire force gauge 4. An installation sleeve 3 is fixedly connected to the outer wall of the support column 2 by bolts, and a force gauge is fixedly connected to the outer wall of the installation sleeve 3. Instrument 4 and mounting sleeve 3 are used to achieve a detachable connection between the force gauge 4 and the support column 2. The force gauge 4 is fixed with bolts, which facilitates installation and subsequent maintenance and replacement, while ensuring the stability of the force gauge 4 on the support column 2. A sliding column 5 is slidably connected inside the base plate 1. The sliding column 5 can slide vertically inside the base plate 1, and the vertical height of the entire force gauge 4 can be changed by sliding adjustment to adapt to the stress assessment needs of tunnel support structures at different heights. Multiple fixing holes 6 are opened on the outer wall of the sliding column 5, which cooperate with subsequent components. The instrument is used to fix the sliding position of the sliding column 5 within the base plate 1. The top of the sliding column 5 is fixedly connected to the top plate 7. A fixing component is provided on the outer wall of the support column 2 to fix the position of the sliding column 5. A stress sensor 10 is installed on the top of the top plate 7. The stress sensor 10 is used to detect the magnitude of the stress transmitted from the tunnel support structure to the force measuring instrument 4. It can convert the sensed stress signal into an electrical signal to provide stress data for subsequent data processing and stress assessment. A connecting column 11 is fixedly connected to the top of the stress sensor 10. The connecting column 11 is used to connect the stress sensor 10 and the leveling component, which plays the role of transmitting force and connecting the two. It ensures that the force generated by the leveling component during the adjustment process can be accurately transmitted to the stress sensor 10. A leveling component is provided on the top of the connecting column 11. The leveling component is used to adjust the flatness of the contact surface between the force measuring component and the tunnel support structure. Since the surface of the tunnel support structure may be uneven, the adjustment of the leveling component can make the force measuring component and the tunnel support structure make close and flat contact, ensuring that the force can be transmitted evenly and improving the accuracy of stress assessment. Reference Figure 3The leveling assembly includes a universal ball joint 12, the bottom of which is fixedly connected to the top of the connecting column 11. The universal ball joint 12 can rotate in multiple directions, allowing the leveling assembly to adjust at multiple angles according to the flatness of the tunnel support structure surface. Three connecting rods 13 are rotatably connected to the outer wall of the universal ball joint 12. The three distributed connecting rods 13 can control the leveling from different directions to ensure the leveling effect. The end of the connecting rod 13 away from the universal ball joint 12 is rotatably connected to an outer rod 14 through a damping shaft. Through the rotation of the damping shaft, the angle of the outer rod 14 can be further finely adjusted so that the outer rod 14 can better adapt to the surface condition of the tunnel support structure. The damping shaft can also keep the position of the outer rod 14 stable after adjustment to prevent random rotation. A limit plate 15 is slidably connected to the inner wall of the outer rod 14. A pressure spring 16 is fixedly connected to one side of the limit plate 15 to limit the pressure spring 16. The sliding path inside the outer rod 14 prevents the pressure spring 16 from sliding excessively out of the outer rod 14 and causing the structure to lose its function. An inner rod 17 is fixedly connected to the other side of the limiting plate 15. The inner rod 17 is used to transmit the elastic force of the pressure spring 16 and the reaction force of the tunnel support structure. By sliding inside the inner rod 17, the length of itself extending out of the outer rod 14 can be adjusted, thereby realizing contact and pressure adjustment with the tunnel support structure. An anti-slip rubber pad 18 is fixedly connected to the side of the inner rod 17 away from the limiting plate 15. The anti-slip rubber pad 18 is used to increase the friction between the inner rod 17 and the surface of the tunnel support structure, preventing relative sliding between the inner rod 17 and the tunnel support structure during the stress assessment process, and ensuring effective force transmission. A locking component is provided on the outer wall of the outer rod 14. The locking component is used to lock the position of the inner rod 17 after the leveling component is adjusted to a suitable position, preventing the inner rod 17 from sliding during the stress assessment process.

[0018] Reference Figure 4 and Figure 5 The locking assembly includes a stop rod 19, the top of which is fixedly connected to the top of the outer rod 14. The stop rod 19 restricts the sliding of the inner rod 17 by abutting against it. When the stop rod 19 and the inner rod 17 are tightly abutted, friction is generated to prevent the inner rod 17 from moving within the outer rod 14. A threaded groove 20 is provided on the outer wall of the stop rod 19, and a threaded sleeve 21 is threadedly connected to the outer wall of the stop rod 19. When the threaded sleeve 21 moves downward, it will exert a squeezing effect on the stop rod 19, making the abutment between the stop rod 19 and the inner rod 17 tighter and enhancing the locking effect. When the threaded sleeve 21 moves upward, the squeezing effect weakens, and the locking of the inner rod 17 can be released, making it convenient to re-level.

[0019] Reference Figure 1 and Figure 2The fixing component includes a fixing pin 8, the outer wall of which is slidably connected to the inner wall of the support column 2. By sliding, it can be inserted into or pulled out of the fixing hole 6 on the sliding column 5, thereby fixing or unlocking the sliding column 5. A locking spring 9 is inserted into the outer wall of the fixing pin 8. A baffle is provided on the side of the outer wall of the fixing pin 8 away from the locking spring 9. The baffle and the locking spring 9 are used to limit the fixing pin 8 to prevent the fixing pin 8 from sliding during operation, which would prevent the fixing hole 6 from being fixed. The fixing pin 8 passes through the support column 2 and engages with the fixing hole 6. The engaging action restricts the sliding of the sliding column 5 in the base plate 1, fixing the sliding column 5 at the current height position, ensuring that the force measuring component can perform stable force assessment at this height.

[0020] Reference Figure 1 and Figure 2 The force gauge 4 and the stress sensor 10 are electrically connected by a wire. The wire enables the transmission of electrical signals between the force gauge 4 and the stress sensor 10, so that the stress electrical signal detected by the stress sensor 10 can be accurately transmitted to the force gauge 4. The force gauge 4 processes and analyzes the received electrical signal and finally displays the force data.

[0021] Reference Figure 4 and Figure 5 One end of the pressure spring 16 away from the limiting plate 15 is fixedly connected to the inner wall of the outer rod 14. Fixing one end of the pressure spring 16 to the inner wall of the outer rod 14 gives the pressure spring 16 a fixed support point during the extension and retraction process, ensuring that the pressure spring 16 can stably generate an elastic force on the limiting plate 15, thereby driving the inner rod 17 to perform stable sliding adjustment.

[0022] Reference Figure 5 The top of the abutment rod 19 is slanted, and the inner wall of the abutment rod 19 and the outer wall of the inner rod 17 abut against each other. The slanted structure provides a reasonable force-bearing surface for the extrusion action of the threaded sleeve 21, so that when the threaded sleeve 21 moves downward, it can more effectively extrude the abutment rod 19, causing the abutment rod 19 to move closer to the inner rod 17 and abut tightly.

[0023] Reference Figure 5 The top of the threaded sleeve 21 is narrower at the top and wider at the bottom. The inner wall of the threaded sleeve 21 abuts against the outer wall of the push rod 19. As the threaded sleeve 21 moves downward, its inner wall can gradually exert greater squeezing force on the inclined structure at the top of the push rod 19. As the threaded sleeve 21 continues to move downward, the squeezing effect gradually increases, which makes the abutment between the push rod 19 and the inner rod 17 tighter and the locking effect better.

[0024] When a stress assessment is required, firstly, adjust the height of the device according to the actual height of the tunnel support structure. Then, pull out the locking spring 9 on the outer wall of the fixing pin 8, and then remove the fixing pin 8 from the support column 2. Next, lift the sliding column 5 upward until the anti-slip rubber pad 18 contacts the tunnel support structure. Then, reinsert the fixing pin 8 into the support column 2, and then insert the locking spring 9 into the fixing pin 8 to fix the fixing pin 8 and the sliding column 5.

[0025] Subsequently, the staff rotated the connecting rod 13, causing the outer rod 14 to adjust its angle, so that the anti-slip rubber pad 18 at the end of the inner rod 17, which is slidably connected to the inner wall of the outer rod 14, initially comes into contact with the surface of the support structure. Since the end of the inner rod 17 away from the anti-slip rubber pad 18 is fixedly connected to the limiting plate 15, and the pressure spring 16 connected to the other side of the limiting plate 15 will elastically expand and contract according to the pressure difference on the surface of the support structure, if the gap between the anti-slip rubber pad 18 and the support structure is large in a certain direction, the pressure spring 16 will push the limiting plate 15 to cause the inner rod 17 to slide outward, so that the anti-slip rubber pad 18 fits tightly against the support structure. If the pressure is too high, the inner rod 17 will compress the pressure spring 16 and retract into the outer rod 14, achieving adaptive adjustment. At the same time, the damping shaft can keep the angle of the outer rod 14 stable during the adjustment process, avoiding random rotation. Finally, through the coordinated adjustment of the three distributed connecting rods 13 and the outer rod 14, the leveling component as a whole keeps in flat contact with the surface of the tunnel support structure, ensuring that the subsequent force is evenly transmitted to the stress sensor 10.

[0026] After leveling, by rotating the threaded sleeve 21, due to the threaded connection between the threaded sleeve 21 and the threaded groove 20, and the fact that the inner wall of the threaded sleeve 21 is narrower at the top and wider at the bottom, the threaded sleeve 21 will slide along the axial direction of the threaded groove 20 when it rotates. When the threaded sleeve 21 slides, it will generate a gradually increasing compressive force on the abutment rod 19 through the abutment. Under the action of the compressive force, the abutment rod 19 will deform inward. Due to the abutment relationship between the inner wall of the abutment rod 19 and the outer wall of the inner rod 17, the friction between the abutment rod 19 and the inner rod 17 will increase when the abutment rod 19 deforms, thereby completing the locking effect on the inner rod 17.

[0027] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A force gauge for rapid stress assessment of tunnel support structures, comprising a base plate (1), characterized in that: The base plate (1) is fixedly connected to the top of a support column (2). The outer wall of the support column (2) is fixedly connected to an installation sleeve (3) by bolts. The outer wall of the installation sleeve (3) is fixedly connected to a force gauge (4). The base plate (1) is slidably connected to a sliding column (5). The outer wall of the sliding column (5) is provided with multiple fixing holes (6). The top of the sliding column (5) is fixedly connected to a top plate (7). The outer wall of the support column (2) is provided with a fixing component. The top of the top plate (7) is equipped with a stress sensor (10). The top of the stress sensor (10) is fixedly connected to a connecting column (11). The top of the connecting column (11) is provided with a leveling component. The leveling assembly includes a universal ball joint (12), the bottom of which is fixedly connected to the top of the connecting column (11). Three connecting rods (13) are rotatably connected to the outer wall of the universal ball joint (12). An outer rod (14) is rotatably connected to one end of the connecting rod (13) away from the universal ball joint (12) via a damping shaft. A limit plate (15) is slidably connected to the inner wall of the outer rod (14). A pressure spring (16) is fixedly connected to one side of the limit plate (15). An inner rod (17) is fixedly connected to the other side of the limit plate (15). An anti-slip rubber pad (18) is fixedly connected to the side of the inner rod (17) away from the limit plate (15). A locking assembly is provided on the outer wall of the outer rod (14).

2. The force gauge for rapid stress assessment of tunnel support structure according to claim 1, characterized in that: The locking assembly includes a stop rod (19), the top of which is fixedly connected to the top of the outer rod (14), and the outer wall of the stop rod (19) is provided with a threaded groove (20), and the outer wall of the stop rod (19) is threadedly connected with a threaded sleeve (21).

3. The force gauge for rapid stress assessment of tunnel support structure according to claim 1, characterized in that: The fixing component includes a fixing pin (8), the outer wall of which is slidably connected to the inner wall of the support column (2), a locking spring (9) is inserted into the outer wall of the fixing pin (8), and the fixing pin (8) passes through the support column (2) and engages with the fixing hole (6).

4. A force gauge for rapid stress assessment of tunnel support structures according to claim 1, characterized in that: The force measuring instrument (4) and the stress sensor (10) are electrically connected by wires.

5. A force gauge for rapid stress assessment of tunnel support structures according to claim 2, characterized in that: The end of the pressure spring (16) away from the limiting plate (15) is fixedly connected to the inner wall of the outer rod (14).

6. A force gauge for rapid stress assessment of tunnel support structures according to claim 2, characterized in that: The top of the abutment (19) is slanted, and the inner wall of the abutment (19) and the outer wall of the inner rod (17) abut against each other.

7. A force gauge for rapid stress assessment of tunnel support structures according to claim 2, characterized in that: The top of the threaded sleeve (21) is narrower at the top and wider at the bottom, and the inner wall of the threaded sleeve (21) and the outer wall of the abutment (19) abut against each other.

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