Roadbed pavement modal tester

Abstract

The invention discloses a roadbed and pavement modal tester, which comprises a test frame, and the bottom of the test frame is detachably connected with a coupling base; one end of the test rod is fixedly connected with a hammer ball; the positioning mechanism is installed at the top end of the testing frame, the testing rod is vertically inserted into the testing frame, and the testing rod is in limiting fit with the positioning mechanism; the height measuring module is mounted at the bottom of the positioning mechanism; the monitoring module is mounted at the bottom of the test frame; the controller is installed on the testing frame, the height measuring module is connected with the controller, a displayer is installed on the testing frame, and the displayer is connected with the controller; and scale marks are arranged on the test rod. According to the invention, the traditional impact test and intelligent monitoring are combined, rapid, accurate and on-site detection of the modal characteristics of the roadbed and the pavement and the rebound height of the hammer ball is realized, the road construction detection technology is enriched, and the road detection efficiency and reliability are significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering, in particular to a roadbed and pavement modal tester. Background Art

[0002] During the roadbed and pavement compaction construction process, continuous monitoring of compaction quality is essential. For soil roadbeds and the base and subbase layers of pavements, the most commonly used method for measuring compaction quality is the compaction index. However, this index cannot accurately reflect the rationality of the roller's compaction process (for example, whether the vibration frequency of a vibratory roller is appropriate). Therefore, it cannot provide a technical reference for optimizing the compaction process and is not adaptable to the requirements of intelligent compaction. For rockfill roadbeds, engineering practice often uses elevation testing to assess compaction quality. This method compares the elevation change at a measuring point before and after compaction to assess whether the rockfill roadbed has reached a stable compaction state. Specifically, if the elevation change at a measuring point after compaction is within the required standard range, it indicates that the compaction of the rockfill roadbed has stabilized and compaction can be stopped. However, this testing method has significant drawbacks. The required equipment and human resources are expensive, and the testing efficiency is low, making it difficult to meet the requirements of large-scale, high-efficiency construction testing. Therefore, there is an urgent need to develop innovative solutions to improve the efficiency of existing testing methods.

[0003] Based on the above technical problems, the present invention provides a roadbed and pavement modal tester, which can perform modal testing on the earth roadbed and pavement base and subbase during the construction process, and can also test the compaction stability of the stone-filled roadbed; the former is very consistent with the needs of intelligent compaction, and the latter has the characteristics of efficient, convenient and economical detection. Summary of the Invention

[0004] The purpose of the present invention is to provide a roadbed and pavement modal tester to solve the problems existing in the prior art.

[0005] To achieve the above object, the present invention provides the following solution: The present invention provides a roadbed and pavement modal tester, comprising: A test stand, the bottom of which is detachably connected to a coupling base; A test rod, one end of which is fixedly connected to a hammer ball; A positioning mechanism, wherein the positioning mechanism is installed at the top of the test frame, the test rod is vertically inserted into the test frame, and the test rod is limitedly matched with the positioning mechanism; A height measuring module is installed at the bottom of the positioning mechanism and is correspondingly arranged between the hammer ball to detect the rebound height of the hammer ball; A monitoring module, mounted at the bottom of the test stand, for monitoring the impact force of the hammer ball striking the coupling base and the speed and acceleration signals of the roadbed and pavement vibration; A controller, the controller is mounted on the test stand, the height measurement module is connected to the controller, the monitoring module is connected to a laptop computer, a display is mounted on the test stand, and the display is connected to the controller; Wherein, the test rod is provided with scale lines.

[0006] According to the roadbed and pavement modal tester provided by the present invention, the test frame includes a top plate and a bottom plate, the top plate is an annular structure, and a plurality of groups of support rods are arranged between the top plate and the bottom plate, and the support rods are arranged at equal intervals around the circumference of the top plate. A protrusion is fixedly connected to the bottom of the bottom plate, and the protrusion is detachably connected to the coupling base. A plurality of mounting grooves are provided on the protrusion, and the monitoring modules are respectively installed in the mounting grooves.

[0007] According to the roadbed and pavement modal tester provided by the present invention, the positioning mechanism is arranged in several groups at equal intervals around the axis of the top plate, the positioning mechanism includes several sliders, and the top plate is provided with several slide grooves at axial intervals, and the several slide grooves are arranged one by one corresponding to the several positioning mechanisms, the axis of the slide groove is perpendicular to the axis of the top plate, and the sliders are slidably connected in the slide grooves, the top of the slider is fixedly connected with a slide plate, the slide plate is slidably connected to the top surface of the top plate, and the top surface of the slide plate is slidably connected with a splint, the splint is an L-shaped structure, the splint is abutted against the test rod, a first elastic compression component is installed between the slide and the splint, a placement groove is provided in the slide groove, a second elastic compression component is installed in the placement groove, the slider is fixed to the second elastic compression component, a control component is installed on the bottom surface of the top plate, and the slider slides on the control component.

[0008] According to the roadbed and pavement modal tester provided by the present invention, the first elastic compression component includes a fixed block, a through groove is provided on the clamping plate, a horizontal groove is provided on the side wall of the through groove, an extrusion block is slidably connected in the horizontal groove, the fixed block is fixedly connected to the top surface of the slide plate, and the fixed block is slidably connected in the through groove, the extrusion block is fixed on the side of the fixed block, a first spring is placed in the horizontal groove, one end of the first spring is fixed to the side of the horizontal groove, and the other end is fixedly connected to the extrusion block.

[0009] According to the roadbed and pavement modal tester provided by the present invention, the second elastic compression assembly includes a second spring, one end of the second spring is fixed to the bottom of the placement groove, the other end of the second spring is fixed to the side of the slider, a telescopic rod is fixedly connected between the slider and the bottom wall of the placement groove, and the second spring is sleeved on the telescopic rod.

[0010] According to the roadbed and pavement modal tester provided by the present invention, the control component includes a pad rotatably connected to the bottom surface of the top plate, the pad is an annular structure, and a plurality of groups of linear grooves are provided on the top surface of the pad at equal intervals in the circumferential direction, the linear grooves are arranged perpendicular to the axis of the pad, a plurality of sliders are respectively arranged corresponding to the plurality of linear grooves, connecting grooves are provided between adjacent linear grooves, and the connecting grooves are respectively connected to one end of the two linear grooves away from each other, the linear grooves are arranged in an inner spiral structure, the slider is slidably matched with the linear grooves and the connecting grooves, the outer wall of the pad is provided with teeth, the bottom surface of the top plate is rotatably connected to a worm through a mounting seat, and the worm is engaged with the teeth.

[0011] According to the roadbed and pavement modal tester provided by the present invention, the height measurement module includes a laser rangefinder, and the laser rangefinder is vertically fixed to the bottom surface of the base plate.

[0012] According to the roadbed and pavement modal tester provided by the present invention, the monitoring module includes a force sensor, an acceleration sensor and a velocity sensor, and the force sensor, the acceleration sensor and the velocity sensor are respectively installed in the installation groove.

[0013] The present invention discloses the following technical effects: 1) The detachable coupling base and modular design facilitate transportation and quick installation, adapting to the on-site testing needs of different roadbeds (earth roadbed, rock fill roadbed) and pavement base and subbase during the compaction process.

[0014] 2) The controller automatically processes data to reduce human error; the display provides real-time feedback on results, enabling "one-click" operation and lowering the professional threshold.

[0015] 3) The scale lines and positioning mechanism ensure that the hammer ball height is adjustable and the falling trajectory is vertical, ensuring consistent test conditions over multiple times and strong data comparability.

[0016] 4) Modal analysis is used to evaluate the modal characteristics of the earthwork roadbed, pavement base, and subbase during the compaction process, providing technical support for the optimization of intelligent compaction or vibration compaction processes and a scientific basis for high-quality compaction decisions.

[0017] 5) The stability of the rock-fill roadbed compaction can be quickly assessed by measuring the rebound height of the hammer ball. That is, when the rebound height at the same measuring point before and after compaction is within the allowable standard range, the compaction is considered to be stable, providing a new technical support for the quality inspection of rock-fill roadbed compaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 Schematic diagram of the structure of the roadbed and pavement modal tester of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 It is a structural schematic diagram of the pad of the present invention.

[0020] Among them, 1. Coupling base; 2. Test rod; 3. Hammer ball; 4. Display; 5. Top plate; 6. Bottom plate; 7. Support rod; 8. Bump; 9. Slide groove; 10. Slider; 11. Slide plate; 12. Clamp; 13. Placement groove; 14. Fixing block; 15. Through groove; 16. Horizontal groove; 17. Extrusion block; 18. First spring; 19. Second spring; 20. Pad; 21. Linear groove; 22. Connecting groove; 23. Worm; 24. Laser rangefinder. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Reference Figure 1-3 The present invention provides a roadbed and pavement modal tester, comprising: A test stand, the bottom of which is detachably connected to a coupling base 1; A test rod 2, one end of which is fixedly connected to a hammer ball 3; Positioning mechanism, the positioning mechanism is installed at the top of the test frame, the test rod 2 is vertically inserted into the test frame, and the test rod 2 is limitedly matched with the positioning mechanism; A height measurement module is installed at the bottom of the positioning mechanism and is correspondingly arranged between the height measurement module and the hammer ball 3 to detect the height change of the hammer ball 3; The monitoring module is installed at the bottom of the test frame and is used to monitor the impact force of the hammer ball 3 hitting the coupling base 1 as well as the speed and acceleration signal of the roadbed and pavement vibration; The controller is installed on the test frame, the height measurement module and the monitoring module are connected to the controller, and a display 4 is installed on the test frame, and the display 4 is connected to the controller; The test rod 2 is provided with scale lines.

[0024] During operation, the test frame is secured to the roadbed or pavement to be tested via the coupling base 1 at its bottom, ensuring stability and close contact with the test surface, minimizing external interference. A test rod 2 is inserted vertically into the test frame, with the hammer ball 3 at its bottom maintaining a certain initial height relative to the roadbed or pavement base or subbase (adjustable via scale lines). This height is locked in place by a positioning mechanism, ensuring the hammer ball 3 falls vertically. When the test rod 2 is released, the hammer ball 3 freely falls and strikes the roadbed or pavement base or subbase, generating excitation vibration. A height measurement module monitors the height changes of the hammer ball 3 during its fall and rebound, generating a curve and capturing the peak value of the initial rebound as a reference. A monitoring module simultaneously records the impact force of the hammer ball 3 striking the coupling base, as well as the velocity and acceleration signals of the vibration of the roadbed or pavement base or subbase, and inputs these signals into a controller. The corresponding software system analyzes these signals to ultimately obtain test data such as frequency and amplitude. Combining this information with the impact force and rebound height, the controller calculates the modal characteristics (natural frequency, damping ratio, etc.) of the roadbed and pavement, as well as the stiffness characteristics of the rockfill roadbed. The results are displayed visually on the display 4 and are used for optimizing the compaction process and evaluating the compaction quality.

[0025] To further optimize the solution, the test frame includes a top plate 5 and a bottom plate 6. The top plate 5 is a ring structure. Several groups of support rods 7 are arranged between the top plate 5 and the bottom plate 6. The support rods 7 are arranged at equal intervals around the top plate 5. A protrusion 8 is fixedly connected to the bottom of the bottom plate 6. The protrusion 8 is detachably connected to the coupling base 1. Several installation grooves are opened on the protrusion 8, and the monitoring modules are respectively installed in the installation grooves.

[0026] To further optimize the solution, several groups of positioning mechanisms are arranged at equal intervals around the axis of the top plate 5, and the positioning mechanism includes several sliders 10. Several slide grooves 9 are opened on the top plate 5 at axial intervals. Several slide grooves 9 are arranged one by one corresponding to several positioning mechanisms, and the axis of the slide groove 9 is perpendicular to the axis of the top plate 5. Sliders 10 are slidably connected in the slide groove 9, and a slide plate 11 is fixedly connected to the top of the slider 10. The slide plate 11 is slidably connected to the top surface of the top plate 5. The top surface of the slide plate 11 is slidably connected to a splint 12. The splint 12 is an L-shaped structure, and the splint 12 abuts against the test rod 2. A first elastic compression component is installed between the slide 11 and the splint 12, and a placement groove 13 is opened in the slide groove 9. A second elastic compression component is installed in the placement groove 13. The slider 10 is fixed to the second elastic compression component, and a control component is installed on the bottom surface of the top plate 5, and the slider 10 slides on the control component.

[0027] A further optimization solution is provided, in which the first elastic compression component includes a fixed block 14, a through slot 15 is provided on the splint 12, a horizontal slot 16 is provided on the side wall of the through slot 15, an extrusion block 17 is slidably connected in the horizontal slot 16, the fixed block 14 is fixedly connected to the top surface of the skateboard 11, and the fixed block 14 is slidably connected in the through slot 15, the extrusion block 17 is fixed to the side of the fixed block 14, a first spring 18 is placed in the horizontal slot 16, one end of the first spring 18 is fixed to the side of the horizontal slot 16, and the other end is fixedly connected to the extrusion block 17.

[0028] To further optimize the solution, the second elastic compression assembly includes a second spring 19, one end of the second spring 19 is fixed to the bottom of the placement groove 13, and the other end of the second spring 19 is fixed to the side of the slider 10. A telescopic rod is fixedly connected between the slider 10 and the bottom wall of the placement groove 13, and the second spring 19 is sleeved on the telescopic rod.

[0029] A further optimized solution is provided, in which the control component includes a pad 20 rotatably connected to the bottom surface of the top plate 5. The pad 20 is an annular structure, and a plurality of groups of linear grooves 21 are provided on the top surface of the pad 20 at equal intervals in the circumferential direction. The linear grooves 21 are arranged perpendicular to the axis of the pad 20, and a plurality of sliders 10 are respectively arranged corresponding to the plurality of linear grooves 21. Connecting grooves 22 are provided between adjacent linear grooves 21, and the connecting grooves 22 are respectively connected to the ends of the two linear grooves 21 away from each other. The linear grooves 21 are arranged in an inner spiral structure, and the slider 10 slides with the linear grooves 21 and the connecting grooves 22. The outer wall of the pad 20 is provided with teeth, and the bottom surface of the top plate 5 is rotatably connected to a worm 23 through a mounting seat, and the worm 23 is engaged with the teeth.

[0030] The coupling base 1 is in contact with the roadbed / pavement base and the subbase, and a detachable connection is achieved through the protrusion 8 at the bottom of the base plate 6 to ensure the stability of the test frame.

[0031] The monitoring module is embedded in the installation slot and directly contacts the roadbed or pavement base and subbase, collecting signals such as hammer force and vibration response in real time.

[0032] The worm 23 rotates to drive the backing plate 20 to rotate, and the linear groove 21 (inner spiral) on the backing plate pushes the slider 10 to move radially along the slide groove 9, thereby achieving synchronous tightening or loosening of multiple groups of clamps 12.

[0033] The clamping plate 12 adaptively clamps the test rod 2 through the first elastic compression assembly (extrusion block 17 + first spring 18).

[0034] The second elastic compression assembly (telescopic rod + second spring 19) buffers the movement of the slider 10 and enhances positioning stability.

[0035] After the test rod 2 is released, the hammer ball 3 falls freely and hits the road surface, generating excitation vibration.

[0036] The height measurement module records the initial height and rebound height changes of the hammer ball 3. The maximum rebound height after different compaction passes indicates that the compaction of the stone-filled roadbed has reached a stable state.

[0037] The vibration response of the roadbed or pavement base and subbase is transmitted to the controller through the monitoring module to analyze the modal parameters (frequency, damping ratio, etc.).

[0038] The height of the test rod 2 is adjusted by the scale line to ensure that the initial release position of the hammer ball 3 is the same during multiple tests, that is, the impact energy is the same each time; the positioning mechanism can be quickly reset to achieve continuous multiple tests.

[0039] Multiple sets of synchronous sliders 10 + inner spiral groove design: The worm 23 drives the pad 20 to rotate, realizing synchronous radial movement of all the splints 12, ensuring that the test rod 2 is always vertically centered to avoid eccentric impact errors.

[0040] The first elastic compression assembly (horizontal spring + extrusion block 17) flexibly clamps the test rod 2 to reduce friction interference during release.

[0041] The second elastic compression assembly (telescopic rod + sleeve spring) stabilizes the movement of the slider 10 to prevent the positioning from loosening.

[0042] Worm 23 - Tooth drive: All clamping plates 12 can be controlled by simply rotating the worm 23, which is easy to operate and has consistent positioning, suitable for fast and repeated testing.

[0043] Modular monitoring unit: The monitoring module in the installation slot can be flexibly configured to meet the expansion needs of different parameters (such as strain and stress).

[0044] Annular top plate 5 + circumferential support rods 7: evenly distribute the load and improve the impact resistance of the test frame.

[0045] The L-shaped clamping plate 12 and the through slot 15 design increase the clamping contact surface and prevent the test rod 2 from slipping or deflecting.

[0046] Removable coupling base 1: Adapts to different road bases, subbase types and uneven sites.

[0047] According to a further optimized solution, the height measurement module includes a laser rangefinder 24 , which is vertically fixed to the bottom surface of the pad 20 .

[0048] To further optimize the solution, the monitoring module includes a force sensor, a velocity sensor and an acceleration sensor, and the force sensor, velocity sensor and acceleration sensor are respectively installed in the installation grooves.

[0049] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying 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.

[0050] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A roadbed and pavement modal tester, characterized in that: include: A test stand, the bottom of which is detachably connected to a coupling base (1); A test rod (2), one end of which is fixedly connected to a hammer ball (3); A positioning mechanism, the positioning mechanism is installed at the top end of the test frame, the test rod (2) is vertically inserted into the test frame, and the test rod (2) is limitedly matched with the positioning mechanism; A height measuring module, the height measuring module being mounted on the bottom of the positioning mechanism, the height measuring module being correspondingly arranged between the hammer ball (3), and being used to detect the height at which the hammer ball (3) rebounds after striking the coupling base; A monitoring module, the monitoring module being mounted on the bottom of the test frame and used to monitor the impact force of the hammer ball (3) striking the coupling base (1) and the speed and acceleration signals of the vibration of the roadbed and pavement; A controller, the controller being mounted on the test stand, the height measurement module and the monitoring module being connected to the controller, a display (4) being mounted on the test stand, and the display (4) being connected to the controller; Wherein, the test rod (2) is provided with scale lines.

2. A roadbed and pavement modal tester according to claim 1, characterized in that: The test stand comprises a top plate (5) and a bottom plate (6), wherein the top plate (5) is an annular structure, and a plurality of groups of support rods (7) are provided between the top plate (5) and the bottom plate (6), wherein the support rods (7) are arranged at equal intervals around the top plate (5), and a protrusion (8) is fixedly connected to the bottom of the bottom plate (6), wherein the protrusion (8) is detachably connected to the coupling base (1), and a plurality of mounting grooves are provided on the protrusion (8), and the monitoring modules are respectively installed in the mounting grooves.

3. A roadbed and pavement modal tester according to claim 2, characterized in that: The positioning mechanism is provided with a plurality of groups at equal intervals around the axis of the top plate (5), and the positioning mechanism includes a plurality of sliders (10). A plurality of slide grooves (9) are provided on the top plate (5) at axial intervals, and the plurality of slide grooves (9) are arranged in one-to-one correspondence with the plurality of positioning mechanisms. The axis of the slide groove (9) is perpendicular to the axis of the top plate (5), and the sliders (10) are slidably connected in the slide grooves (9). The top of the slider (10) is fixedly connected with a slide plate (11), and the slide plate (11) is slidably connected to the top surface of the top plate (5). The top surface of the slide plate (11) is slidably connected to a clamping plate (12), the clamping plate (12) is an L-shaped structure, the clamping plate (12) is in contact with the test rod (2), a first elastic compression component is installed between the slide plate (11) and the clamping plate (12), a placement groove (13) is provided in the slide groove (9), a second elastic compression component is installed in the placement groove (13), the slider (10) is fixed to the second elastic compression component, a control component is installed on the bottom surface of the top plate (5), and the slider (10) slides on the control component.

4. A roadbed and pavement modal tester according to claim 3, characterized in that: The first elastic compression assembly includes a fixed block (14), a through slot (15) is provided on the clamping plate (12), a horizontal slot (16) is provided on the side wall of the through slot (15), an extrusion block (17) is slidably connected in the horizontal slot (16), the fixed block (14) is fixedly connected to the top surface of the slide plate (11), and the fixed block (14) is slidably connected in the through slot (15), the extrusion block (17) is fixed to the side of the fixed block (14), a first spring (18) is placed in the horizontal slot (16), one end of the first spring (18) is fixed to the side of the horizontal slot (16), and the other end is fixedly connected to the extrusion block (17).

5. The roadbed and pavement modal tester according to claim 3, characterized in that: The second elastic compression assembly includes a second spring (19), one end of the second spring (19) is fixed to the bottom of the placement groove (13), and the other end of the second spring (19) is fixed to the side of the slider (10). A telescopic rod is fixedly connected between the slider (10) and the bottom wall of the placement groove (13), and the second spring (19) is sleeved on the telescopic rod.

6. The roadbed and pavement modal tester according to claim 3, characterized in that: The control component includes a pad (20) rotatably connected to the bottom surface of the top plate (5), the pad (20) is an annular structure, and a plurality of groups of linear grooves (21) are opened at equal intervals on the top surface of the pad (20) in the circumferential direction, the linear grooves (21) are arranged perpendicular to the axis of the pad (20), a plurality of sliders (10) are respectively arranged corresponding to the plurality of linear grooves (21), a connecting groove (22) is arranged between adjacent linear grooves (21), and the connecting grooves (22) are respectively connected to the ends of the two linear grooves (21) away from each other, the linear grooves (21) are arranged in an inner spiral structure, the slider (10) is slidably matched with the linear grooves (21) and the connecting grooves (22), the outer wall of the pad (20) is provided with tooth grooves, the bottom surface of the top plate (5) is rotatably connected to a worm (23) through a mounting seat, and the worm (23) is engaged with the tooth grooves.

7. The roadbed and pavement modal tester according to claim 6, characterized in that: The height measurement module comprises a laser rangefinder (24), and the laser rangefinder (24) is vertically fixed on the bottom surface of the backing plate (20).

8. The roadbed and pavement modal tester according to claim 2, characterized in that: The monitoring module includes a force sensor, an acceleration sensor and a speed sensor, and the force sensor, the acceleration sensor and the speed sensor are respectively installed in the installation groove.

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