阅读说明：本技术 一种路面下陷检测系统及检测方法 (Pavement subsidence detection system and detection method ) 是由 陈锐 吴月成 金好乾 万正华 朱江华 于 2020-11-09 设计创作，主要内容包括：本发明涉及一种路面下陷检测系统及检测方法。检测系统包括：设置在路面下方且与路面间隔预设间距的光纤光栅传感器；设置在光纤光栅传感器外部的应变传导层；与光纤光栅传感器连接,根据通过光纤光栅传感器的光波的波长确定光纤光栅传感器的应变大小的信号处理装置。本方案通过外部荷载(主要是汽车荷载)对路面的作用,使得位于路面下方布设的光纤光栅传感器中通过的光波的波长发生改变,从而确定光纤光栅传感器中的光栅的应变大小,即光栅发生了多少位移,从而确定光栅对应的路面的应变大小。(The invention relates to a pavement subsidence detection system and a detection method. The detection system comprises: the fiber grating sensor is arranged below the road surface and is spaced from the road surface by a preset distance; the strain conducting layer is arranged outside the fiber grating sensor; and the signal processing device is connected with the fiber grating sensor and determines the strain magnitude of the fiber grating sensor according to the wavelength of the light wave passing through the fiber grating sensor. According to the scheme, the wavelength of light waves passing through the fiber grating sensor arranged below the road surface is changed under the action of an external load (mainly an automobile load) on the road surface, so that the strain magnitude of the grating in the fiber grating sensor, namely the displacement of the grating is determined, and the strain magnitude of the road surface corresponding to the grating is determined.)

1. A system for detecting sagging of a road surface, said detection system comprising:

the fiber grating sensor is arranged below the road surface and is spaced from the road surface by a preset distance;

a strain conducting layer disposed outside the fiber grating sensor;

and the signal processing device is connected with the fiber grating sensor and determines the strain magnitude of the fiber grating sensor according to the wavelength of the light wave passing through the fiber grating sensor.

2. The system of claim 1, wherein the fiber grating sensor comprises:

the fiber bragg grating sensing probe array is formed by detachably connecting at least two fiber bragg grating sensing probes.

3. The system of claim 2, wherein the fiber grating sensing probe comprises:

a sleeve;

the optical fibers are arranged in the sleeve, and two ends of the optical fibers are respectively fixed at two ends of the sleeve; movable gratings are engraved on the optical fibers;

a protective layer disposed outside the sleeve;

the protective layer includes: a high temperature resistant isolation tube and a basalt fiber packaging layer.

4. The pavement sag detection system according to claim 1, wherein the strain conducting layer comprises:

an elastic straight rod;

a flexible metal sleeve sleeved outside the elastic straight rod; the fiber bragg grating sensor is arranged in the elastic straight rod;

and the strain transmission guide posts are arranged on the inner wall of the flexible metal sleeve at intervals and are in contact with the elastic straight rod.

5. The system for detecting pavement sagging according to claim 4, wherein both ends of said flexible metal sleeve are provided with sealing caps;

a connecting wire penetrating hole is formed in the sealing cover.

6. The pavement sag detection system according to claim 4, wherein the strain conducting layer further comprises:

and the waterproof roll is arranged outside the elastic straight rod.

7. The road surface sag detection system according to claim 4,

the flexible metal sleeve is made of a galvanized steel strip, or the flexible metal sleeve is made of a steel strip and electrical paper.

8. A pavement sag detection system according to any one of claims 4 to 7, wherein the first and second sensors are disposed on the front and rear sides of the chassis,

at least one of a polyvinyl chloride coated sleeve, an aluminum belt coated sleeve and a stainless steel belt coated sleeve is arranged outside the flexible metal sleeve.

9. A method for detecting a sinking of a road surface, the method comprising:

acquiring the wavelength of light waves passing through corresponding gratings of each position point on a road surface, wherein a fiber grating sensor is arranged at a preset position below the road surface, and the gratings in the fiber grating sensor correspond to the position points;

obtaining the strain of the corresponding position point according to the wavelength of the light wave;

and determining a first position point of the road surface depression according to the strain of each position point.

10. The road surface sagging detection method according to claim 9, characterized by comprising:

obtaining the natural vibration frequency of the elastic straight rod according to the wavelength of the light wave; the fiber bragg grating sensor is arranged inside the elastic straight rod;

obtaining a natural vibration frequency change point according to the natural vibration frequency of the elastic straight rod;

determining a second position point of the road surface depression according to the self-vibration frequency change point;

and obtaining a third position point of the road surface depression according to the first position point and the second position point.

Technical Field

The invention relates to the technical field of bridge and highway maintenance and informatization automatic acquisition, in particular to a system and a method for detecting subsidence of a pavement.

Background

In recent years, with the vigorous development of traffic construction industry, more and more new roads and bridges are put into operation and use stages, but with the increase of operation period, a series of problems occur inevitably on the structure itself, and one of the phenomena is the bump at the bridge head.

The phenomenon of vehicle jump at the bridge head is mainly caused by that the road surface parts at the two ends of the bridge and culvert sink relative to the bridge floor, and the platform is staggered due to overlarge sinking amount, so that the vehicle jumps and jolts. The phenomenon of vehicle bump at the bridge head exists more or less in the transition section between the bridge and the road surface, so that the comfort of riding is reduced, the driver can generate the psychology of road rage, and even traffic accidents are caused. And the horizontal and vertical acting force generated by vehicle jumping at the bridge head applies additional impact load to the bridge structure, accelerates the damage of the abutment, the bridge head butt strap and the expansion joint, thereby increasing the maintenance cost of the bridge.

The phenomenon of vehicle jumping is easy to occur at the bridge position, the position of a pit hole or a well cover of a road and the like on the road surface is easy to occur, and particularly, the problem of vehicle jumping is more serious when the pit hole or the road surface sinks at a high speed.

Disclosure of Invention

In order to solve the problems in the prior art, at least one embodiment of the invention provides a system and a method for detecting a road surface subsidence.

In a first aspect, an embodiment of the present invention provides a system for detecting a sinking of a road surface, where the system includes:

the fiber grating sensor is arranged below the road surface and is spaced from the road surface by a preset distance;

a strain conducting layer disposed outside the fiber grating sensor;

and the signal processing device is connected with the fiber grating sensor and determines the strain magnitude of the fiber grating sensor according to the wavelength of the light wave passing through the fiber grating sensor.

Based on the above technical solutions, the embodiments of the present invention may be further improved as follows.

With reference to the first aspect, in a first embodiment of the first aspect, the fiber grating sensor includes:

the fiber bragg grating sensing probe array is formed by detachably connecting at least two fiber bragg grating sensing probes.

With reference to the first embodiment of the first aspect, in a second embodiment of the first aspect, the fiber grating sensing probe includes:

a sleeve;

the optical fibers are arranged in the sleeve, and two ends of the optical fibers are respectively fixed at two ends of the sleeve; movable gratings are engraved on the optical fibers;

a protective layer disposed outside the sleeve;

the protective layer includes: a high temperature resistant isolation tube and a basalt fiber packaging layer.

In combination with the first aspect, in a third embodiment of the first aspect, the strained conductive layer includes:

an elastic straight rod;

a flexible metal sleeve sleeved outside the elastic straight rod; the fiber bragg grating sensor is arranged in the elastic straight rod;

and the strain transmission guide posts are arranged on the inner wall of the flexible metal sleeve at intervals and are in contact with the elastic straight rod.

With reference to the third embodiment of the first aspect, in a fourth embodiment of the first aspect, two ends of the flexible metal sleeve are provided with sealing caps;

a connecting wire penetrating hole is formed in the sealing cover.

In combination with the third embodiment of the first aspect, in a fifth embodiment of the first aspect, the strained conductive layer further comprises:

and the waterproof roll is arranged outside the elastic straight rod.

With reference to the third embodiment of the first aspect, in a sixth embodiment of the first aspect,

the flexible metal sleeve is made of a galvanized steel strip, or the flexible metal sleeve is made of a steel strip and electrical paper.

With reference to the third, fourth, fifth or sixth embodiments of the first aspect, in a seventh embodiment of the first aspect,

at least one of a polyvinyl chloride coated sleeve, an aluminum belt coated sleeve and a stainless steel belt coated sleeve is arranged outside the flexible metal sleeve.

In a second aspect, an embodiment of the present invention provides a method for detecting a sinking of a road surface, where the method includes:

acquiring the wavelength of light waves passing through corresponding gratings of each position point on a road surface, wherein a fiber grating sensor is arranged at a preset position below the road surface, and the gratings in the fiber grating sensor correspond to the position points;

obtaining the strain of the corresponding position point according to the wavelength of the light wave;

and determining a first position point of the road surface depression according to the strain of each position point.

With reference to the second aspect, in a first embodiment of the second aspect, the detection method includes:

obtaining the natural vibration frequency of the elastic straight rod according to the wavelength of the light wave; the fiber bragg grating sensor is arranged inside the elastic straight rod;

obtaining a natural vibration frequency change point according to the natural vibration frequency of the elastic straight rod;

determining a second position point of the road surface depression according to the self-vibration frequency change point;

and obtaining a third position point of the road surface depression according to the first position point and the second position point.

Compared with the prior art, the technical scheme of the invention has the following advantages: according to the embodiment of the invention, the wavelength of light waves passing through the fiber grating sensor arranged below the road surface is changed under the action of an external load (mainly an automobile load) on the road surface, so that the strain magnitude of the grating in the fiber grating sensor, namely the displacement of the grating, is determined, and the strain magnitude of the road surface corresponding to the grating is determined.

Drawings

Fig. 1 is a schematic structural diagram of a pavement subsidence detection system provided in an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a fiber grating sensor array according to another embodiment of the present invention;

FIG. 3 is a schematic diagram of a strain conducting layer structure in a system for detecting sagging of a road surface according to another embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of a flexible metal sleeve according to yet another embodiment of the present invention;

FIG. 5 is a schematic axial cross-sectional view of a flexible metal sleeve according to yet another embodiment of the present invention;

fig. 6 is a schematic flow chart of a road surface subsidence detection method according to another embodiment of the present invention;

fig. 7 is a schematic flow chart of a road surface subsidence detection method according to another embodiment of the present invention.

In the figure: 1: a pavement; 2: a signal processing device; 3: a fiber grating sensing probe; 4: a sleeve; 5: a protective layer; 6: an optical fiber; 7: a grating; 8: a fiber grating sensor; 9: an elastic straight rod; 10: waterproof coiled materials; 11: a flexible metal sleeve; 12: a sealing cover; 13: the connecting line penetrates through the hole.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1, an embodiment of the present invention provides a road surface sag detection system. Referring to fig. 1, the detection system includes:

the fiber grating sensor is arranged below the road surface and is spaced from the road surface by a preset distance;

the strain conducting layer is arranged outside the fiber grating sensor;

and the signal processing device is connected with the fiber grating sensor and determines the strain magnitude of the fiber grating sensor according to the wavelength of the light wave passing through the fiber grating sensor.

The basic principle of the scheme is that based on the effect of an external load (mainly an automobile load) on a road surface, the wavelength of light waves passing through the fiber grating sensor arranged below the road surface is changed, so that the strain magnitude of the grating in the fiber grating sensor, namely the displacement of the grating, is determined, and the strain magnitude of the road surface corresponding to the grating is determined. Specifically, the strain variation amplitude is clearly reflected to be basically stable when the road surface is smooth in the strain measurement result, and when the road surface has a height difference phenomenon (vehicle bump at the bridge head), the strain can generate a sudden change phenomenon at the position, so that the position point coordinate of the vehicle bump at the bridge head can be obtained by finding a strain sudden change point.

The strain refers to the local relative deformation of an object under the action of factors such as external force and a non-uniform temperature field. The strain transmitting layer arranged outside the fiber grating sensor can protect the fiber grating sensor and can transmit the strain of the ground to the fiber grating sensor.

The optical fiber outlet of the fiber grating sensor is connected to the signal processing device through an optical fiber, the signal processing device can also be connected to an active light source of the fiber grating sensor through a lead, and the active light source is controlled to emit light so as to provide a light source for the fiber grating sensor.

As shown in fig. 2, in the present embodiment, the fiber grating sensor includes: the fiber bragg grating sensing probe array is formed by detachably connecting at least two fiber bragg grating sensing probes.

In this embodiment, the fiber grating sensing probes are sequentially connected in series to obtain a fiber grating sensor probe array, wherein an active light source is disposed at one end of the fiber grating sensing probe array to provide a light source for the fiber grating sensor probe array.

Specifically, the length of the fiber grating sensing probe array can be freely set by a user, and the more fiber grating sensing probes are connected, the longer the fiber grating sensing probe array is.

In this embodiment, the fiber grating sensing probe includes: a sleeve; the optical fibers are arranged in the sleeve, and two ends of the optical fibers are respectively fixed at two ends of the sleeve; movable grating is engraved on the optical fiber; a protective layer disposed outside the sleeve; the protective layer includes: a high temperature resistant isolation tube and a basalt fiber packaging layer.

In this embodiment, the fiber grating sensing probe includes a sleeve, an optical fiber enclosed in the sleeve, and a grating inscribed on the optical fiber. The two ends of the optical fiber are respectively fixed at the two ends of the sleeve, the grating can freely slide in the sleeve, the distance between the two fixed points is the set gauge length, and the length of the gauge length can be defined and set according to the requirements of users.

As shown in fig. 3 and 4, in the present embodiment, the strained conductive layer includes: an elastic straight rod; a flexible metal sleeve sleeved outside the elastic straight rod; the fiber bragg grating sensor is arranged in the elastic straight rod; and the strain transmission guide posts are arranged on the inner wall of the flexible metal sleeve at intervals and are in contact with the elastic straight rod.

In this embodiment, the elastic straight rod may be made of fiber reinforced plastic, and the fiber grating sensor and the elastic straight rod made of fiber reinforced plastic are packaged together to be integrated, so as to ensure that the strain of the elastic straight rod can affect the fiber grating sensor inside.

In this embodiment, set up the elasticity straight-bar to the compliance metal sleeve pipe in, keep apart the elasticity straight-bar with the ground, avoid soil environment direct and elasticity straight-bar contact to corrode the elasticity straight-bar, the compliance metal sleeve pipe possesses certain pliability simultaneously, can meet an emergency when the road surface takes place, produce certain deformation in step, set up a plurality of meeting an emergency at compliance metal sleeve pipe inner wall simultaneously and pass the guide pillar for meet an emergency and pass the guide pillar and contact with the elasticity straight-bar, conduct the deformation of compliance metal sleeve pipe to the elasticity straight-bar.

As shown in fig. 4 and 5, in the present embodiment, two ends of the flexible metal sleeve are provided with sealing caps; the sealing cover is provided with a connecting wire through hole.

In this embodiment, the connecting wire is worn out the hole and is included optic fibre and wear the hole with the wire to make things convenient for the cable to wear out, more preferred, still be provided with the shrink sealing ring on the connecting wire is worn out the hole, can wear out the back at the cable, inwards shrink seals, in order to avoid the intraductal electronic components of compliance metal sleeve to contact external environment and appear damaging.

In this embodiment, the strained conductive layer further comprises: the waterproof roll is arranged outside the elastic straight rod. The waterproof coiled material is arranged outside the elastic straight rod, and other waterproof structures such as a waterproof coating can be adopted, but the strain transmission guide post is in contact with the elastic straight rod, so that the waterproof coiled material is adopted to improve the durability of the waterproof structure, and the elastic straight rod is prevented from being corroded due to the fact that the waterproof coiled material is in contact with a water environment.

The waterproof coiled material is sleeved outside the elastic straight rod, and the interior of the elastic straight rod is packaged by fiber reinforced plastics, so that the integral material has extremely excellent water resistance and corrosion resistance. After being packaged by an external metal sleeve, the packaging material is more suitable for various environments with severe conditions, thereby having higher durability and wide applicability.

In the present embodiment, the flexible metal sleeve is made of a galvanized steel strip, or the flexible metal sleeve is made of a steel strip and an electrical paper.

In this embodiment, the flexible metal sleeve is externally provided with at least one of a polyvinyl chloride-clad sleeve, an aluminum-clad sleeve, and a stainless-steel-clad sleeve. According to different project environments, the special PVC coating, aluminum strip coating and stainless steel strip coating sleeve for adapting to outdoor, high-temperature, high-cold and clean or corrosive gas environments

As shown in fig. 6, an embodiment of the present invention provides a road surface sag detecting method. Referring to fig. 5, the detection method includes the steps of:

and S11, acquiring the wavelength of the light wave passing through the corresponding grating of each position point on the road surface, wherein a fiber grating sensor is arranged at a preset position below the road surface, and the grating in the fiber grating sensor corresponds to each position point.

In this embodiment, through set up the fiber grating sensor in road surface below soil layer, when there is the circumstances of sinking in the road surface, the vehicle that passes through can exert a bigger power to the road surface because the car jump of vehicle to lead to there being the strain of the position of sinking can be bigger than the strain of other positions, can confirm the circumstances on road surface through comparing the strain size.

And S12, obtaining the strain of the corresponding position point according to the wavelength of the light wave.

The basic principle of the scheme is that based on the effect of an external load (mainly an automobile load) on a road surface, the wavelength of light waves passing through a fiber grating sensor arranged below the road surface is changed, so that the strain magnitude of a grating in the fiber grating sensor, namely the displacement of the grating, is determined, and the strain magnitude of the road surface corresponding to the grating is determined. Specifically, the strain variation amplitude is clearly reflected to be basically stable when the road surface is smooth in the strain measurement result, and when the road surface has a height difference phenomenon (vehicle bump at the bridge head), the strain can generate a sudden change phenomenon at the position, so that the position point coordinate of the vehicle bump at the bridge head can be obtained by finding a strain sudden change point.

And S13, determining a first position point of the road surface depression according to the strain of each position point.

In this embodiment, in the strain, when the long gauge length fiber grating bridge head vehicle-jumping monitoring system is buried under the road surface, when there is a phenomenon of vehicle-jumping at the bridge head, an extra vertical impact force is generated at the position point due to the existence of the slope, and the impact force will cause the strain of the position point to be increased compared with the time of vehicle-jumping without the bridge head, so that the position of vehicle-jumping at the bridge head can be judged by identifying the strain of the position point through the wavelength characteristics of the grating.

As shown in fig. 7, compared with the detection method shown in fig. 6, the difference is that the detection method further includes the following steps:

s21, obtaining the natural frequency of the elastic straight rod according to the wavelength of the light wave; the fiber bragg grating sensor is arranged inside the elastic straight rod.

In this embodiment, the strain generated by the grating in the fiber grating sensor, that is, the displacement generated by the grating, is determined according to the wavelength of the light wave passing through the fiber grating sensor arranged in the elastic straight rod, and since the wavelength of the light wave passing through is changed due to the displacement of the grating, in this embodiment, the change of the position of the grating can be obtained according to the change of the wavelength of the light wave, so that the strain of the grating in the fiber grating sensor can be obtained.

And S22, obtaining a natural vibration frequency change point according to the natural vibration frequency of the elastic straight rod.

And S23, determining a second position point of the road surface depression according to the self-vibration frequency change point.

In this embodiment, as above, the second position point of the road surface depression can be determined from the change point of the natural frequency of the elastic straight rod.

And S24, obtaining a third position point of the road surface depression according to the first position point and the second position point.

In the embodiment, in the natural vibration frequency, when the phenomenon of vehicle bump at the bridge head exists, the amplitude of the natural vibration of the elastic straight rod is increased, and the position point of the vehicle bump at the bridge head can be determined by finding the change point of the natural vibration frequency.

In this embodiment, a more accurate third position point is determined by synchronously adjusting the determined second position point and the determined first position point, so as to improve the accuracy of the point at the position where the road surface is sunken, wherein the third position point can be obtained in an average manner according to the first position point and the second position point, the third position point can be obtained by correcting the first position point through the second position point, the weight assignment can be performed on the first position point and the second position point, and the third position point can be obtained according to the weight value and the left side of the position point.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.