CN201034984Y - Sound vibrating method cement road surface panel bottom disengaging detector - Google Patents
Sound vibrating method cement road surface panel bottom disengaging detector Download PDFInfo
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- CN201034984Y CN201034984Y CNU2007200507990U CN200720050799U CN201034984Y CN 201034984 Y CN201034984 Y CN 201034984Y CN U2007200507990 U CNU2007200507990 U CN U2007200507990U CN 200720050799 U CN200720050799 U CN 200720050799U CN 201034984 Y CN201034984 Y CN 201034984Y
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- drop hammer
- method cement
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Abstract
The utility model discloses an acoustic-vibration method cement road panel bottom disengaging detection device, including a drop hammer, a drop hammer lifting device, a directional sound sensor, a fourier converter, a characteristics parameter calculator, and a disengaging discriminator. The directional sound sensor directs to the drop hammer to knock the road and is connected with the fourier converter. The fourier converter is connected with the characteristics parameter calculator, and the characteristics parameter calculator is connected with the disengaging discriminator. The characteristics parameter calculator includes the power spectrum area calculator, a formant frequency calculator, a centroid calculator with the power spectrum area at the X shaft, the centroid calculator and the formant frequency calculator with the power spectrum area at the Y shaft. The utility model has advantages of convenient operation, fast and correct detecting and low price.
Description
Technical Field
The utility model relates to a detection technology, in particular to detector that comes to nothing at the bottom of sound vibration method cement pavement slab of coming to nothing at the bottom of cement pavement slab.
Background
The cement pavement void is one of the diseases difficult to treat in the cement pavement diseases, and because the void occurs at the bottom of a cement concrete slab, the pavement surface has no obvious characteristics, thereby causing certain difficulty in treating the void. Because of the important influence of the void on the service performance of the road surface, road workers at home and abroad make a great deal of research on void detection and treatment. At present, the method for judging the concrete pavement void mainly comprises the following steps:
(1) Appearance discrimination method
Includes manually observing the vibration of the board when the vehicle passes by, the phenomena of water and mud pumping at the joint seam in rainy days, and the like, and the existence of mud sediment at the edge of the joint seam.
(2) Method of manual impact
The method needs an experienced person to judge whether the plate is empty or not by knocking the plate edge with an iron chisel and judging whether the plate is empty according to different sounds, and only can the plate with obvious empty is judged.
(3) Deflection discrimination method
And measuring the deflection of two adjacent plates by adopting a Beckman beam, and comprehensively judging according to the deflection value of the bearing plate and the deflection difference between the bearing plate and the bearing plate without the bearing plate.
(4) Multi-stage load regression method
The method adopts a Falling Weight Deflectometer (FWD) to carry out multi-level load loading, draws different load deflectometer regression lines and carries out the judgment of the void.
(5) Inverse analysis method
And measuring the deflection value of the pavement through FWD, calculating the modulus of each layer of the pavement structure in a reverse mode, and comparing the theoretical deflection value of the plate edge with the measured deflection value to judge the void.
In the method, the appearance discrimination method and the manual impact method are simple to operate, have multiple human factors and poor accuracy and cannot quantify; the deflection discrimination method is simple in calculation, but low in precision and incapable of accurately quantifying, the determined emptying standard is related to the structure, the emptying standard needs to be corrected aiming at different structures, and the method is not wide in applicability; the results obtained by different back calculation programs of the inversion analysis method are also different; the multi-level load regression method is dependent on detection equipment FWD to determine that the detection cost is much higher than that of other detection methods, besides, road sections needing to be additionally paved and modified are mostly road sections which are passing through vehicles, in order to not influence the traffic additional paving, usually only one road section of one lane is closed, the FWD is inconvenient to detect a plate corner close to one side of passing through vehicles due to large size, and turning around is inconvenient (freeway access control and bidirectional direction division driving). Therefore, there are many inconveniences in inspection and acceptance of grouting. Therefore, a detection method with the characteristics of convenient operation, flexibility, rapidness, accuracy and low cost is urgently needed in actual production.
SUMMERY OF THE UTILITY MODEL
The utility model aims to overcome the not enough of prior art, provide a convenient operation, nimble, quick, accurate, sound vibration method cement pavement slab end void detector that the cost is low.
Realize the technical scheme of the utility model as shown in figure 1: a cement pavement slab bottom void detector by a sound vibration method comprises a drop hammer, a drop hammer lifting device, a directional sound sensor, a Fourier transformer, a characteristic parameter calculator and a void discriminator, wherein the directional sound sensor points to the position where the drop hammer strikes the pavement, the directional sound sensor is connected with the Fourier transformer, the Fourier transformer is connected with the characteristic parameter calculator, the characteristic parameter calculator is connected with the void discriminator, and the characteristic parameter calculator comprises a power spectrum area calculator, a resonance peak frequency calculator, a centroid calculator of the power spectrum area in the X-axis direction, a centroid calculator of the power spectrum area around the Y-axis and a resonance peak amplitude calculator.
In order to reduce the noise of the drop hammer after the drop hammer impacts the road surface, the drop hammer is specially designed, and as shown in fig. 4, the drop hammer comprises a rod body 103 and a hammer body 109; the rod body 103 is provided with a convex brim 102, the lower end of the rod body 103 is biconvex, and the lower end is provided with a conical concave; the hammer body 109 is formed by combining a trapezoidal cone and a hemispherical body, a convex brim is arranged at the combined part, more than 3 through holes 108 are arranged in the convex brim, the angles of the conical parts of the rod body 103 and the hammer body 109 are consistent, the rod body 103 is provided with through holes 105 corresponding to the through holes 108 of the hammer body, the rod body 103 and the hammer body 109 are fixed together by bolts 104, and a plastic gasket 106 corresponding to the through holes 107 is cushioned in the middle.
In order to reduce the noise when the drop hammer falls, as shown in fig. 4, a plastic cladding 101 is provided from a convex brim 102 on the rod body of the drop hammer to the upper end of the rod body.
In order to further reduce the noise when the drop hammer falls, as shown in fig. 4, a plastic cladding 101 is also provided at a position about 10cm below the eaves 102 on the rod body of the drop hammer to the lower end of the rod body.
As shown in fig. 6, the drop hammer lifting device comprises a screw rod 3, a motor 6 which drives the screw rod to rotate and can rotate forwards and backwards, a guide rail 7 which is parallel to the screw rod, and a hammer catching mechanism 5; the hammer grabbing mechanism 5 is matched with the screw rod 3, and the hammer grabbing mechanism 5 is driven to move up and down along the guide rail 7 by the rotation of the screw rod 3; the hammer catching mechanism 5 comprises a clamping jaw 20, an electromagnet 21 and a positioning ring 19, and the rod 103 of the drop hammer 1 penetrates through the clamping jaw 20 and the positioning ring 19.
In order to reduce the noise when the drop hammer falls, as shown in fig. 7, 3 or more strings 22 are fixed to the positioning ring 19, and the strings 22 prevent the rod 103 of the drop hammer 1 from touching the positioning ring 19 and generating noise.
To further reduce the noise of the system, the jaws 20 may be covered with a plastic coating.
The method for detecting the floor separation of the cement pavement slab by using the sound vibration method comprises the following steps of:
(1) The cement pavement is hit by a drop hammer, and the cement board makes a sound;
(2) The directional sound sensor obtains a sound signal emitted by the cement board and transmits the sound signal to the PC, and the PC performs subsequent processing;
(3) The sound signal is converted into a frequency domain signal through Fourier transformation;
(4) Calculating the power spectrum area according to the frequency domain signal, wherein the calculation formula is
In the formula: pi is the power spectrum amplitude corresponding to each frequency,
k is the number of collected samples;
(5) Calculating the formant frequency according to the frequency domain signal by the formula
Fres＝F(Pi.max)；
In the formula: fi is the frequency corresponding to each power spectrum amplitude;
(6) According to the frequency domain signal, calculating the mass center of the power spectrum area in the X-axis direction by the formula
(7) According to the frequency domain signal, calculating the mass center of the power spectrum area in the Y-axis direction by the formula
(8) Calculating the amplitude of the formants according to the frequency domain signal by the following formula
Amp＝A(Pi.max)；
(9) And (5) according to the calculation results of the steps (4) to (8), carrying out discrimination according to the following discrimination functions:
Y＝Y 0 +Y 1 ×AREA+Y 2 ×Fres+Y 3 ×C X +Y 4 ×C Y +Y 5 ×Amp；
if the calculated Y is less than 0, the cement board is in a compact state, otherwise, if the Y is more than 0, the cement board is in a void state, and if the Y =0, the cement board is in a weak support state;
in the above formula, Y 0 、Y 1 、Y 2 、Y 3 、Y 4 、Y 5 The specific data is obtained by curve fitting according to the test data.
The above formula is preferred:
Y＝4.59492-0.0021×AREA-13.9658×Fres
+0.05971×C X -0.00023×C Y -5.62116×Amp。
the utility model discloses for prior art have following advantage and effect:
(1) The adoption of the directional sound sensor weakens the interference of vehicle noise on the detection signal;
(2) The operation is convenient;
(3) The detection is rapid and accurate;
(4) The cost is low.
Drawings
Fig. 1 is a structural block diagram of the detector of the present invention.
Fig. 2 is a schematic diagram of the internal structure of the detector of the present invention.
Fig. 3 is a schematic front view of an embodiment of the detector of the present invention.
Fig. 4 is a schematic view of the structure of the drop hammer.
Fig. 5 is a schematic top view of the drop hammer.
Fig. 6 is a schematic view of a lifting device.
Fig. 7 is a schematic view of a retaining ring string.
Shown in the figure are, 1: drop weight, 2: drop hammer fixing device, 3: screw rod, 4: a storage battery, 5: hammer grasping mechanism, 6: motor, 7: guide rail, 8: case, 9: electric control device, 10: set screw, 11: power inverter, 12: directional sound sensor, 13: power switch, 14: start button, 15: up limit switch, 16: down limit switch, 17: up-to-position indicator lamp, 18: clamp indicator, 19: positioning ring, 20: jaw, 21: electromagnet, 22, string, 101: plastic envelope, 102: convex eaves, 103: a rod body, 104: bolt, 105: through-hole, 106: plastic gasket, 107: gasket through hole, 108: through hole, 109: a hammer body.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings.
Fig. 1 is the utility model discloses the structure of detector shows the block diagram, and the surface of water road surface sound after the drop hammer striking ground, directional sound sensor acquires behind this sound signal and becomes the frequency domain signal by fourier transform ware transform, and fourier transform formula is:
<x(τ)，g t，Ω (τ)>＝<x(τ)，g(t-τ)e jΩτ dτ>＝STFT x (t，Ω)
in the formula:
Ω =2 π f, in rad/s
After Fourier transformation, 5 sound characteristic parameters such as power spectrum area, formant frequency, the mass center of the power spectrum area in the X-axis direction, the mass center of the power spectrum area around the Y axis, formant amplitude and the like are extracted from a frequency domain, and then the void is judged according to a judgment formula by a void judger.
Fig. 2 is a schematic diagram of an internal structure of an embodiment of the detector of the present invention, fig. 3 is a corresponding schematic diagram of a front panel, and fig. 6 is a corresponding schematic diagram for more simplicity. FIG. 1 shows a drop hammer for striking the ground to generate sound; 2, a drop hammer fixing device is used for preventing the drop hammer from damaging other parts in transportation; 3 is a screw rod; 4 is a storage battery; the hammer grabbing mechanism 5 is characterized in that after the electromagnet 21 controls the clamping jaw 20 to close and lift the drop hammer 1 to the upper limit position, the electromagnet is powered off by manually pressing the starting button 14, the clamping jaw 20 is loosened, the ascending in-place indicator lamp 17 is turned off, and the drop hammer 1 falls down and strikes the ground; 6 is a motor; 7 is a guide rail which limits the motion direction of the hammer grasping mechanism; 8 is a casing, protecting the internal structure; 9. the electric control device is used for controlling power on and off and controlling the lifting of the drop hammer; 10 is a fixing screw to prevent the falling hammer from damaging other parts in transportation; reference numeral 11 denotes a power inverter for supplying power to the motor 6, the electromagnet 21, and the like; 12 is a directional sound sensor; 13 is a power switch; 14 is a start button; the reference numeral 15 is an ascending limit switch, the hammer grasping mechanism ascends to touch the ascending limit switch 15, the motor immediately stops rotating, and an ascending in-place indicator lamp 17 is turned on; a descending limit switch 16, the hammer grasping mechanism descends to contact with the descending limit switch 16, and the motor stops rotating along with the descending limit switch; 17 is an up-to-position indicator light; 18: and a clamping indicator lamp.
The detection process of the detector is as follows:
the main power switch 13 is turned on to obtain power, after the start button 14 is pressed, the clamping jaw 20 clamps the drop hammer 1, the clamping indicator lamp 18 is on, the motor 6 drives the screw rod 3 to drive the hammer clamping mechanism to ascend, the drop hammer 1 ascends to a certain height to touch the upper limit switch 15 to stop, and the ascending in-place indicator lamp 17 is on; after the start button 14 is pressed, the clamping jaw 20 is loosened, the clamping indicator lamp 18 is turned off, the ascending in-place indicator lamp 17 is turned off, the drop hammer 1 falls freely, the hammer grabbing mechanism 5 is driven by the screw rod 3 to fall and trigger to the lower limit switch 15 to stop, then the clamping jaw 20 clamps the drop hammer 1, the clamping indicator lamp 18 is turned on, the motor 6 drives the screw rod 3 to drive the hammer grabbing mechanism to rise, the drop hammer 1 rises to a certain height to trigger the upper limit switch 15 to stop, the ascending in-place indicator lamp 17 is turned on, and the next detection is waited to be carried out by manually pressing the start button 14.
Fig. 4 is a schematic structural view of the drop hammer of the embodiment, and fig. 5 is a corresponding schematic top view. As can be seen from fig. 5, in the present embodiment, the bolts 104 are fixed by 6 bolts 104, but the number of the bolts 104 is not necessarily 6, and may be 3 or more. For the convenience of transportation, the upper end of the rod 103 of the drop hammer 1 can be provided with a screw hole for fixing.
Fig. 7 is a schematic view of a retaining ring string. In the figure, the number of the strings is 8, but not necessarily 8, and more than 3 strings are enough to ensure that the rod body 103 of the drop hammer 1 does not touch the positioning ring, but to ensure that the rod body 103 has a certain free swing space and the free fall of the drop hammer 1 cannot be damaged.
Claims (7)
1. The utility model provides a detector that comes to nothing at bottom of sound vibration method cement pavement slab, includes drop hammer, drop hammer hoisting device, its characterized in that: the device comprises a directional sound sensor, a Fourier transformer, a characteristic parameter calculator and a void discriminator, wherein the directional sound sensor points to the position of a falling hammer knocking road surface, the directional sound sensor is connected with the Fourier transformer, the Fourier transformer is connected with the characteristic parameter calculator, the characteristic parameter calculator is connected with the void discriminator, and the characteristic parameter calculator comprises a power spectrum area calculator, a formant frequency calculator, a centroid calculator of the power spectrum area in the X-axis direction, a centroid calculator of the power spectrum area around the Y-axis and a formant amplitude calculator.
2. The acoustic vibration method cement pavement slab bottom void detector according to claim 1, characterized in that: the drop hammer comprises a rod body and a hammer body: the lower end of the rod body is biconvex, and the lower end of the rod body is provided with a conical concave; the hammer body is formed by combining a trapezoid cone and a hemispherical body, a convex brim is arranged at the combined position, more than 3 through holes are arranged in the convex brim, the angles of the conical positions of the rod body and the hammer body are consistent, the rod body is provided with through holes corresponding to the through holes of the hammer body, the rod body and the hammer body are fixed together by bolts, and a plastic gasket with corresponding through holes is padded in the middle.
3. The acoustic vibration method cement pavement slab bottom void detector according to claim 2, characterized in that: and a plastic cladding is arranged from the convex brim on the rod body of the drop hammer to the upper end of the rod body.
4. The acoustic vibration method cement pavement slab bottom void detector according to claim 3, characterized in that: the convex eaves on the rod body of the drop hammer are downward to the lower end of the rod body, and a plastic cladding is arranged on the lower end of the rod body.
5. The acoustic vibration method cement pavement slab bottom void detector according to claim 4, characterized in that: the drop hammer lifting device comprises a screw rod, a motor which drives the screw rod to rotate and can rotate forward and backward, a guide rail parallel to the screw rod and a hammer grabbing mechanism; the hammer grabbing mechanism is matched with the screw rod, and is driven to move up and down along the guide rail by the rotation of the screw rod; the hammer grabbing mechanism comprises a clamping jaw, an electromagnet and a positioning ring, and a rod body of the drop hammer penetrates through the clamping jaw and the positioning ring.
6. The acoustic vibration method cement pavement slab bottom void detector according to claim 5, characterized in that: more than 3 strings are fixed on the positioning ring, and the strings can prevent the rod body of the drop hammer from touching the positioning ring to generate noise.
7. The acoustic vibration method cement pavement slab bottom void detector according to claim 6, characterized in that: the clamping jaw is provided with a plastic cladding.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007200507990U CN201034984Y (en) | 2007-04-26 | 2007-04-26 | Sound vibrating method cement road surface panel bottom disengaging detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007200507990U CN201034984Y (en) | 2007-04-26 | 2007-04-26 | Sound vibrating method cement road surface panel bottom disengaging detector |
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| Publication Number | Publication Date |
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| CN201034984Y true CN201034984Y (en) | 2008-03-12 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNU2007200507990U Expired - Fee Related CN201034984Y (en) | 2007-04-26 | 2007-04-26 | Sound vibrating method cement road surface panel bottom disengaging detector |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106153725A (en) * | 2016-08-17 | 2016-11-23 | 西安长大公路养护技术有限公司 | A kind of pavement distress detection equipment and detection method thereof |
| CN109765303A (en) * | 2019-01-18 | 2019-05-17 | 湘潭大学 | The detection method for degree of coming to nothing behind for liner structure |
| CN110108615A (en) * | 2019-04-13 | 2019-08-09 | 北京润宏技术检测有限公司 | A kind of infiltration gradient testing machine and its experimental control method for coarse-grained soil |
-
2007
- 2007-04-26 CN CNU2007200507990U patent/CN201034984Y/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106153725A (en) * | 2016-08-17 | 2016-11-23 | 西安长大公路养护技术有限公司 | A kind of pavement distress detection equipment and detection method thereof |
| CN109765303A (en) * | 2019-01-18 | 2019-05-17 | 湘潭大学 | The detection method for degree of coming to nothing behind for liner structure |
| CN109765303B (en) * | 2019-01-18 | 2021-06-15 | 湘潭大学 | Detection method for void degree behind lining structure |
| CN110108615A (en) * | 2019-04-13 | 2019-08-09 | 北京润宏技术检测有限公司 | A kind of infiltration gradient testing machine and its experimental control method for coarse-grained soil |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080312 Termination date: 20120426 |