CN214843375U - Fiber grating sensing roadway surrounding rock safety monitoring system with anchor rod as sensing medium - Google Patents

Abstract

The utility model discloses an use fiber grating sensing tunnel country rock safety monitoring system of stock as sensing media, include: the device comprises a plurality of anchor rod sensors, an optical fiber demodulator, a host and a protection box body; the optical fiber demodulator is respectively connected with the host and the plurality of anchor rod sensors and arranged in the protective box body; each anchor rod sensor comprises an anchor rod main body, a fiber bragg grating and an anchoring and protecting ring; the fiber bragg grating is arranged in the groove of the anchor rod main body, wherein the fiber bragg grating comprises optical fibers and gratings; the protection circular ring is sleeved at a preset distance of the tail end of the anchor rod main body, and the anchor is arranged at the tail end of the anchor rod main body; the anchor of one anchor rod sensor is welded on the outer side of the protective box body; the optical fiber demodulator is used for respectively acquiring wavelength information detected by each anchor rod sensor and respectively demodulating each wavelength information to generate corresponding wavelength data; and the host is used for analyzing the wavelength data and carrying out safety assessment on the surrounding rocks of the roadway.

Description

Fiber grating sensing roadway surrounding rock safety monitoring system with anchor rod as sensing medium

Technical Field

The utility model relates to a tunnel country rock safety monitoring system technical field, in particular to use fiber grating sensing tunnel country rock safety monitoring system of stock as sensing media.

Background

In the construction process of roadway excavation, the rock in the excavation range is usually removed by adopting a blasting mode, wherein when explosive is exploded in a drilling hole (blast hole), the rock in the excavation range can be blasted, but simultaneously, the stability of the roadway surrounding rock is inevitably influenced, and even damage or destruction is caused, so that the mechanical property of the roadway surrounding rock is deteriorated, and the surrounding bearing capacity and the stability of the roadway surrounding rock are reduced.

At present, the conditions such as internal stress deformation and the like are not easy to observe due to the limitation of conditions such as blasting environment, monitoring technology and the like, and the safety of construction is seriously influenced.

Disclosure of Invention

The present invention aims at solving at least one of the technical problems in the above-mentioned technology to a certain extent. Therefore, an object of the utility model is to provide an use the stock as sensing medium's fiber grating sensing tunnel country rock safety monitoring system, can monitor the displacement condition of each partial different degree of depth of tunnel country rock, provide sufficient data for the safety precaution of exploitation scene to realize the monitoring of tunnel country rock blasting stability, and then ensure relevant staff's personal safety.

In order to achieve the above object, the utility model provides an use fiber grating sensing tunnel country rock safety monitoring system of stock as sensing media, include: the device comprises a plurality of anchor rod sensors, an optical fiber demodulator, a host and a protective box body, wherein the optical fiber demodulator is respectively connected with the host and the anchor rod sensors, and the optical fiber demodulator and the host are arranged in the protective box body; each anchor rod sensor comprises an anchor rod main body, a fiber bragg grating, an anchoring ring and a protection ring, wherein the anchor rod main body is provided with a groove along the axis direction, and the initial position of the groove is the tail end of the anchor rod main body; the fiber bragg grating is arranged in the groove, wherein the fiber bragg grating comprises an optical fiber and a grating, and the grating is etched on the optical fiber and is arranged at equal intervals; the protection circular ring is sleeved on the anchor rod main body at a preset distance away from the tail end of the anchor rod main body, and the anchor is arranged at the tail end of the anchor rod main body; the anchor of one anchor rod sensor in the plurality of anchor rod sensors is welded on the outer side of the protective box body; the optical fiber demodulator is used for respectively acquiring wavelength information detected by each anchor rod sensor and respectively demodulating the wavelength information detected by each anchor rod sensor so as to generate wavelength data corresponding to each anchor rod sensor; and the host is used for carrying out safety assessment on the surrounding rock of the roadway according to the wavelength data corresponding to each anchor rod sensor.

The utility model discloses an use the stock as fiber grating sensing tunnel country rock safety monitoring system of sensing medium, at first detect through a plurality of stock sensors, then gather the wavelength information that every stock sensor detected respectively through the optical fiber demodulation appearance, and demodulate the wavelength information that every stock sensor detected respectively, generate the wavelength data that every stock sensor corresponds, the wavelength data that corresponds through every stock sensor of host computer analysis at last carries out safety assessment to tunnel country rock, therefore, can monitor the displacement condition of the each partial different degree of depth of tunnel country rock, safety precaution for the exploitation scene provides sufficient data, thereby realize the monitoring of tunnel country rock blasting stability, and then ensure relevant staff's personal safety.

Additionally, according to the utility model discloses the above-mentioned fiber grating sensing tunnel country rock safety monitoring system who uses the stock as sensing media who proposes can also have following additional technical characterstic:

specifically, the host is connected with the optical fiber demodulator through a network cable.

Specifically, the length of the groove is 1.2m, the groove is a groove of 5mm × 5mm, and the length of the groove is smaller than that of the anchor rod main body.

In particular, the anchoring is a mechanical anchoring.

Specifically, the fiber grating is adhered in the groove through epoxy resin glue.

Furthermore, a plurality of detection holes are formed in the roadway surrounding rock, and the anchor rod sensors are respectively inserted into the detection holes; wherein the anchoring and protection ring of the anchor rod sensor is positioned outside the detection hole.

Specifically, one optical fiber is led out from the tail end of each anchor rod main body, the led-out optical fiber is connected with the optical fiber demodulator through the anchor, and the optical fiber led out from the tail end of each anchor rod main body is respectively connected with the optical fiber demodulator, or the optical fiber led out from the tail end of each anchor rod main body is connected with the optical fiber demodulator after being connected in series.

Specifically, the internal diameter of protection ring is 20mm, the external diameter of protection ring is 45mm, the thickness of protection ring is 30 mm.

Further, the host includes: the first acquisition module is used for acquiring wavelength data corresponding to the anchor rod sensor welded on the outer side of the protection box body and taking the wavelength data corresponding to the anchor rod sensor welded on the outer side of the protection box body as reference wavelength data; the analysis module is used for analyzing the reference wavelength data to determine a target time period; the second acquisition module is used for extracting target wavelength data from the wavelength data corresponding to each anchor rod sensor according to the target time period; and the safety evaluation module is used for extracting target wavelength data from the wavelength data corresponding to each anchor rod sensor and carrying out safety evaluation on the roadway surrounding rock.

Specifically, the sampling rate of the fiber-optic demodulator is 500 Hz.

Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic block diagram of a fiber grating sensing roadway surrounding rock safety monitoring system using an anchor rod as a sensing medium according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a rock bolt sensor according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a fiber grating sensing roadway surrounding rock safety monitoring system using an anchor rod as a sensing medium according to another embodiment of the present invention;

fig. 4 is a schematic structural diagram of a fiber grating sensing roadway surrounding rock safety monitoring system using an anchor rod as a sensing medium according to another embodiment of the present invention;

fig. 5 is a schematic structural diagram of a fiber grating sensing roadway surrounding rock safety monitoring system using an anchor rod as a sensing medium according to another embodiment of the present invention;

fig. 6 is a schematic block diagram of a host structure according to an embodiment of the present invention;

fig. 7 is a view illustrating a construction method of an anchor according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a four bolt sensor arrangement according to an embodiment of the present invention;

fig. 9 is a graph of first bolt sensor monitoring data according to an embodiment of the present invention;

fig. 10 is a graph of second bolt sensor monitoring data according to an embodiment of the present invention;

fig. 11 is a third anchor sensor monitoring data graph according to an embodiment of the present invention;

fig. 12 is a graph of fourth bolt sensor monitoring data according to an embodiment of the present invention;

fig. 13 is a graph of vibration signals measured by a second anchor sensor according to an embodiment of the present invention;

fig. 14 is a graph of vibration signals measured by a third anchor sensor according to an embodiment of the present invention;

fig. 15 is a graph of vibration signals measured by a fourth anchor sensor according to an embodiment of the present invention;

fig. 16 is a wavelet exploded view of the vibration signal measured by the second anchor sensor as scale 5 according to an embodiment of the present invention;

fig. 17 is a wavelet exploded view of the vibration signal measured by the third anchor sensor as scale 5 according to an embodiment of the present invention;

fig. 18 is a wavelet decomposition view of the vibration signal measured by the fourth anchor sensor as dimension 5 according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

The fiber grating sensing roadway surrounding rock safety monitoring system using the anchor rod as the sensing medium according to the embodiment of the present invention is described below with reference to the accompanying drawings.

Fig. 1 is a schematic block diagram of a fiber grating sensing roadway surrounding rock safety monitoring system using an anchor rod as a sensing medium according to an embodiment of the present invention.

As shown in fig. 1, the fiber grating sensing roadway surrounding rock safety monitoring system 100 using the anchor rod as the sensing medium, which is provided by the embodiment of the present invention, can include: a plurality of anchor sensors 110, a fiber optic detuner 121, a main unit 122, and a protective case 120.

The optical fiber demodulation instrument 121 can be respectively connected with the host 122 and the plurality of anchor rod sensors 110, and the optical fiber demodulation instrument 121 and the host 122 can be arranged in the protective box 120. In addition, a plurality of anchor sensors 110 may be respectively connected to the optical fiber detuner 121.

Specifically, as shown in fig. 2, each of the plurality of anchor rod sensors 110 may include an anchor rod body 210, a fiber grating 201 (not specifically identified in the figure), a protection ring 230, and an anchor 240, wherein the anchor rod body 210 may be provided with a groove 220 along an axial direction, and a starting position of the groove 220 may be a tail end of the anchor rod body 210. The inner diameter of the protection ring 230 may be 20mm, the outer diameter may be 45mm, and the thickness may be 30mm, and the protection ring may be used to protect the fiber grating from being damaged by external force. The protection ring 230 is sleeved on the anchor rod main body 210 at a preset distance from the tail end of the anchor rod main body 210, and the anchor 240 is arranged at the tail end of the anchor rod main body 210, wherein the preset distance can be calibrated according to actual conditions.

Further, the fiber grating 201 may include an optical fiber 21 (not specifically identified in the figures) and a grating 22 (not specifically identified in the figures). The plurality of gratings 22 are etched on the optical fiber 21 and are disposed at equal intervals, that is, the plurality of gratings 22 are etched on the optical fiber 21 at equal intervals. The anchor 240 of one of the plurality of anchor sensors 110 may be welded to the outside of the protective casing 120, for example, vertically welded to the outside of the protective casing 120, wherein the anchor 240 is a mechanical anchor. As shown in fig. 2, an optical fiber 21 may be led out from the tail end of the anchor body 210, and the led optical fiber 21 may be connected to the optical fiber demodulation instrument 121 through an anchor 240.

It should be noted that the protection ring 230 described in this embodiment is welded at a distance of 60mm from the end of the anchor rod (i.e., 60mm from the left end of the anchor 240), and the specific configuration thereof can be seen in fig. 2.

In an embodiment of the present invention, the fiber grating 201 may be adhered to the groove 220 by epoxy glue.

Specifically, the fiber grating 201 can be uniformly adhered in the groove 220 through epoxy resin glue, so that the fiber grating 201 does not generate local stress, and the monitoring initial value of the fiber grating 201 is ensured. In addition, the related staff can measure the packaging condition of the grating 22 after the epoxy resin glue is stabilized, and compare the packaging condition with the factory value of the grating 22.

Further, in another embodiment of the present invention, the length of the groove 220 may be 1.2m, the groove 220 may be a 5mm × 5mm groove (i.e., the depth of the groove is 5mm, and the width is 5mm), and the length of the groove 220 is less than the length of the anchor body 210. Wherein, relevant staff can select the stock of suitable length according to actual conditions and detection demand, does not do any restriction here.

In one embodiment of the present invention, as shown in fig. 3, the host 122 may be connected to the fiber demodulation instrument 121 through the network cable 10.

In other embodiments of the present invention, the host 122 may also be connected to the fiber demodulation instrument 121 through an optical fiber.

The optical fiber demodulator 121 may be configured to collect wavelength information detected by each anchor rod sensor, and demodulate the wavelength information detected by each anchor rod sensor, so as to generate wavelength data corresponding to each anchor rod sensor. The sampling rate of the fiber-optic demodulator 121 may be 500 Hz.

The host 122 may be configured to perform safety assessment on the roadway surrounding rock according to the wavelength data corresponding to each anchor rod sensor.

In an embodiment of the present invention, the optical fiber led out from the tail end of each anchor body of the plurality of anchor sensors 110 is connected to the optical fiber demodulator 121, or the optical fiber led out from the tail end of each anchor body is connected to the optical fiber demodulator 121 after being connected in series.

Specifically, referring to fig. 4, assuming that the fiber grating sensing roadway surrounding rock safety monitoring system 100 using the anchor rod as a sensing medium has four anchor rod sensors, the four anchor rod sensors may be respectively: a first anchor sensor 410, a second anchor sensor 420, a third anchor sensor 430 and a fourth anchor sensor 440. The first anchor sensor 410, the second anchor sensor 420, the third anchor sensor 430 and the fourth anchor sensor 440 are connected to the optical fiber demodulation instrument 121 through the optical fiber 20, the optical fiber 30, the optical fiber 40 and the optical fiber 50 led out from the tail end of the anchor body, respectively.

Alternatively, referring to fig. 5, the first anchor sensor 410, the second anchor sensor 420, the third anchor sensor 430 and the fourth anchor sensor 440 may be connected in series by optical fibers led out from the tail end of the anchor body and then connected as an optical fiber path to the optical fiber demodulation instrument 121 through the optical fiber 60.

In an embodiment of the present invention, as shown in fig. 6, the host 122 may include a first obtaining module 610, a parsing module 620, a second obtaining module 630, and a security evaluation module 640.

The first obtaining module 610 is configured to obtain wavelength data corresponding to an anchor rod sensor welded to the outer side of the protection box 120, and use the wavelength data corresponding to the anchor rod sensor welded to the outer side of the protection box as reference wavelength data. The parsing module 620 is configured to parse the reference wavelength data to determine a target time period. The second obtaining module 630 is configured to extract wavelength data from the wavelength data corresponding to each anchor sensor according to the target time period. The safety evaluation module 640 is used for extracting a target wavelength from the wavelength data corresponding to each anchor rod sensor to perform safety evaluation on the surrounding rock of the roadway.

Specifically, the utility model discloses an use the stock as the in-process of sensing the work of fiber grating sensing tunnel country rock safety monitoring system of sensing medium, at first, the first acquisition module 610 in the host computer 122 acquires the wavelength data of the sensor of welding in the protection box 120 outside to regard this wavelength data as reference wavelength data. The parsing module 620 then parses the reference wavelength data to determine the start time and duration of the blast. Next, the second obtaining module 630 extracts wavelength data from the wavelength data corresponding to each sensor in the blasting time period (i.e., the target time period), respectively. Finally, the safety evaluation module 640 extracts the target wavelength from the wavelength data corresponding to each anchor rod sensor, and performs safety evaluation on the surrounding rock of the roadway. Therefore, the stability of the roadway surrounding rock after blasting is monitored, and more sufficient guarantee is provided for the safety early warning prediction of the mining site, so that the personal safety of related workers is ensured.

For clarity of the above embodiment, in an embodiment of the present invention, a plurality of detection holes are formed on the surrounding rock of the roadway, and the plurality of anchor rod sensors 110 are respectively inserted into the plurality of detection holes, wherein the anchor 240 and the protection ring 230 of the anchor rod sensor 110 may be located outside the detection holes.

Specifically, related workers can select a position close to a blasting place as a detection place according to detection requirements, and can also select a position perpendicular to a blasting roadway to reduce the influence of blasting shock waves as the detection place so as to ensure the safety of the related workers; and a plurality of detection holes are arranged on the surrounding rock of the roadway at the detection site, and the anchor rod sensors are respectively inserted into the detection holes.

The method comprises the steps of detecting the position of a detection hole, punching the position where a roof fall rib caving accident easily occurs in the process of selecting the position of the detection hole, and also punching the hole by selecting different rock environment conditions according to the purpose of detection. In a concrete anchor construction mode, referring to fig. 7, one of the plurality of anchor sensors 110 is inserted into the inspection hole 700, wherein the protection ring 230 and the anchor 240 are located outside the inspection hole 700.

It should be noted that, the position of the test site described in the above embodiment may be selected to be about 10m away from the blasting surface, or may be selected to be closer to the blasting surface, so that the obtained detection data will be more obvious, and the relevant worker may select a suitable detection site according to the actual situation and the detection requirement, which is not limited herein.

The utility model discloses an in the embodiment, four stock sensors of relevant staff's optional: the first anchor sensor 410, the second anchor sensor 420, the third anchor sensor 430 and the fourth anchor sensor 440 are respectively arranged at a detection site, and respectively acquire corresponding first wavelength data, second wavelength data, third wavelength data and fourth wavelength data, and a specific arrangement manner can be seen in fig. 8.

The first anchor rod sensor 410 can be installed in a detection hole in the surrounding rock of the roadway at the intersection angle of the main roadway and the branch roadway; the second anchor rod sensor 420 can be installed in a detection hole on the surrounding rock of the roadway in a branch roadway perpendicular to the blasting roadway and is far away from the blasting surface; the third anchor rod sensor 430 can be installed in a detection hole in the surrounding rock of the roadway in the axial direction of the main roadway; the fourth anchor sensor 440 is vertically welded to the outside of the protective case 120 through the anchors 240.

Specifically, the protection box 120 described in the above embodiments is used to place the fiber demodulation instrument 121 and the host 122, and is disposed in the branch roadway, away from the blasting surface, so as to reduce the impact of blasting impact on the instrument and also reduce the damage of moisture on the instrument so as to avoid large errors.

The embodiment of the utility model provides an in, the data volume that produces is great at the in-process that uses the stock as sensing media's fiber grating sensing tunnel country rock safety monitoring system work, can select wherein important some data to carry out the analysis. In the aspect of data processing, during analysis, the micro-strain can be selected as a Y coordinate to replace a monitored wavelength value so as to show a change value of the monitoring wavelength of each anchor rod sensor.

The data of the blasting process show the detection process of the anchor rod sensor in the aspect of the dynamic state, the vibration data recorded by the instrument during blasting is selected during dynamic analysis, the whole recording time can be 1.7400 seconds, 871 data are recorded, the blasting vibration duration time is about 0.3760 seconds, and the detected strain variation range is about 10 micro-strains. As shown in fig. 9 to 12, the monitoring data of the first anchor rod sensor 410, the second anchor rod sensor 420, the third anchor rod sensor 430 and the fourth anchor rod sensor 440 in the blasting process are respectively, the fluctuation condition in the data is modified to a certain extent, and the influence of noise is removed.

Specifically, referring to fig. 9, the first anchor rod sensor 410 is located at the intersection angle of the main roadway and the branch roadway, and is closer to the blast surface than the other three anchor rod sensors, so that more wavelength information is obtained and the wavelength data (first wavelength data) is more obvious. The data in the figure show that the blasting lasts for a short time, the vibration of the rock is small, and the blasting time and the rock vibration condition are fully reflected.

Referring to fig. 10, the second anchor sensor 420 is located in a branch roadway perpendicular to the blasting roadway, away from the blasting surface, and is less affected by the shock wave, and the wavelength information obtained in the blasting process is less, and the wavelength data (second wavelength data) is not obvious. In the blasting process, the change trend of the early-stage wavelength is large, the peak value reaches 4 microstrain, and a plurality of positions reach the peak value. After blasting, clutter disturbance is great, about 2 microstrain, and the leading cause is that paste fiber grating when initial encapsulation sensor makes the sensor have an initial prestressing force, has produced certain influence to the testing effect to the data result of detecting has been influenced from the certain limit.

As can be seen in fig. 9 and 10, the first anchor sensor 410 measures more significantly than the second anchor sensor 420, thereby indicating that the sensors are placed closer to the blast surface to detect more significant and subtle changes in strain.

Referring to fig. 11, the third anchor rod sensor 430 is located in the axial direction of the main roadway, directly bears the blasting impact, is most affected in the blasting process, and is affected by the blasting aftershock, the acquired wavelength data changes before and after blasting, and the numerical value of the interference wave after blasting is large. The maximum peak value of the wavelength data in the blasting process is 4.5 microstrain, and the peak value is reached for many times. Therefore, the sensor is placed on the blasting main roadway without damage to the sensor and can detect the vibration data more effectively.

Referring to fig. 12, the fourth anchor rod sensor 440 is located outside the protection box 120 and far away from the blasting surface, the fourth anchor rod sensor 440 is affected by the blasting impact and oscillates outside the protection box 120 to cause a large strain change (reaching a maximum peak value), the obtained wavelength data (fourth wavelength data) well shows the time and process of the blasting, and can be used as reference wavelength data, and the wavelength data obtained by the other three anchor rod sensors can be used for quickly finding the time range of the blasting with reference to the reference wavelength data. As can be seen from the figure, before blasting, the curve area is gentle; after blasting, the curve changes obviously and has certain fluctuation. The temperature change in the range of the sensing area of the fourth anchor sensor 440 after blasting may be reflected by the change in the wavelength after blasting, and thus the fourth anchor sensor 440 may be used as a temperature sensor. As shown in table 1, some important data in the dynamic test are selected based on several values of the fourth anchor sensor 440 having large variation fluctuation.

TABLE 1

The data in table 1 shows that the initial time of the blasting process in the above embodiment is 0, and at 0.226 seconds, the data detected by the fourth anchor sensor 440 reaches the first peak, and the data detected by the other anchor sensors also reaches the first peak in the period: the data detected by the first anchor sensor 410 reaches a first peak at time 0.224 seconds, the data detected by the second anchor sensor 420 reaches a first peak at time 0.218 seconds, and the data detected by the third anchor sensor 430 reaches a first peak at time 0.222 seconds. At the time 0.276 second, the data detected by the fourth anchor sensor 440 reaches the maximum peak value in the blasting process, and the blasting shock wave is transmitted to the protective box 120, at this time, the strain value of the data detected by the first anchor sensor 410 and the third anchor sensor 430 changes while the first anchor sensor and the third anchor sensor are still fluctuating, and the data detected by the second anchor sensor 420 is closer to the fourth anchor sensor 440 and also reaches the maximum peak value.

The utility model discloses an in an embodiment, use the stock to be sensing media's fiber grating sensing tunnel country rock safety monitoring system can adopt wavelet analysis to handle monitoring signal, at first do initialization processing and filtering with the signal that the monitoring obtained, then carry out wavelet decomposition analysis.

In the process of monitoring the blasting, the frequency of the vibration signal is generally below 200Hz, the sampling frequency of the optical fiber demodulator can be 500Hz, and the Nyquist frequency is 250Hz according to the Shannon sampling theorem, so that the blasting vibration signal can be subjected to wavelet decomposition with the scale of 5 according to the wavelet decomposition principle. Thus, the original signal is divided into 6 sub-bands in the whole frequency domain, and the bandwidths of the 6 sub-bands are: 0-7.8125Hz, 7.8125-15.625Hz, 15.625-31.25Hz, 31.25-62.5Hz, 62.5-125Hz, 125-250 Hz.

Specifically, the fiber bragg grating sensing roadway surrounding rock safety monitoring system using the anchor rod as the sensing medium in the above embodiment analyzes and processes the signal, and the second anchor rod sensor 420, the third anchor rod sensor 430 and the fourth anchor rod sensor 440 can be taken as an example to perform typical analysis. Signals measured by the second anchor sensor 420, the third anchor sensor 430 and the fourth anchor sensor 440 are respectively shown in fig. 13-15. The fourth anchor rod sensor 440 is located outside the protective box 120, and is located at a special position, so that the vibration waves do not pass through a rock medium in the process of being transmitted to the fourth anchor rod sensor 440, delay is small, and attenuation is lowSmall, so that the signal change amplitude is large, and can be up to 50X 10^-3nm, which is relatively large in amplitude compared to the other two sensors, and thus the monitoring signal of the fourth anchor sensor 440 can be used as a reference for the other two sensors to determine the time for the blast vibration wave to reach the nearby rock region and the vibration duration. The wavelet exploded views of the monitoring signals of the second anchor sensor 420, the third anchor sensor 430 and the fourth anchor sensor 440 are respectively shown in fig. 16-18.

As can be seen from fig. 16 and 17, the monitoring signals of the second anchor sensor 420 and the third anchor sensor 430 fluctuate strongly in the time domain and are mixed with noise signals, so that it is not easy to determine the time of the explosion vibration wave and the duration of the action. The blasting vibration wave can be analyzed and judged to be transmitted to the monitoring position from 0.2-0.4 second according to the monitoring signal of the fourth anchor rod sensor 440.

Therefore, the surrounding rock (i.e., the target surrounding rock) monitored by the second anchor rod sensor 420 is complete and has no obvious cracks, and the internal deformation strain of the rock is not large and is not easy to expand in the whole vibration process. The surrounding rock (i.e., target surrounding rock) monitored by the third anchor sensor 430 is very rapidly propagated through wavelet analysis of the signal thereof.

As can be seen from fig. 18, the initial time of the blasting process is time 0, and at time 0.226 seconds, the monitoring signal of the fourth anchor sensor 440 reaches the first peak, and the signals monitored by the other sensors also change greatly (i.e., reach the first peak) during the time period, which can be reflected by the peak fluctuation that is obvious in the rough part of the wavelet decomposition. At the time 0.276 seconds, the monitoring signal of the fourth anchor sensor 440 reaches the maximum peak value in the blasting process, at this moment, the blasting shock wave is transmitted to the protective box body 120, the second anchor sensor 420 and the third anchor sensor 430 still oscillate in the fluctuation process, the oscillation data shows that the fiber bragg grating in the sensors has wavelength change, and the strain deformation in the rock body monitored by the second anchor sensor 420 and the third anchor sensor 460.

From this, use the stock to handle the data that can acquire the change of rock mass internal strain to monitoring signal adoption wavelet analysis as sensing medium's fiber grating sensing tunnel country rock safety monitoring system, the inside deformation condition of monitoring rock mass, the displacement condition of each part different degree of depth of tunnel country rock promptly can carry out safety assessment to tunnel country rock, ensures relevant staff's personal safety.

To sum up, the utility model discloses use the stock to acquire wavelength information as fiber grating sensing tunnel country rock safety monitoring system of sensing medium, at first, detect through a plurality of stock sensors, then gather the wavelength information that every stock sensor detected respectively through the optical fiber demodulation appearance, and demodulate the wavelength information that every stock sensor detected respectively, generate the wavelength data that every stock sensor corresponds, the wavelength data that corresponds through every stock sensor of host computer analysis at last carries out the safety assessment to tunnel country rock, therefore, can monitor the displacement condition of the each partial different degree of depth of tunnel country rock, safety precaution for the exploitation scene provides sufficient data, thereby realize the monitoring of tunnel country rock blasting stability, and then ensure relevant staff's personal safety.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (10)

1. The utility model provides an use fiber grating sensing tunnel country rock safety monitoring system of stock as sensing media which characterized in that includes: a plurality of anchor rod sensors, an optical fiber demodulator, a host and a protective box body, wherein,

the optical fiber demodulator is respectively connected with the host and the plurality of anchor rod sensors, and the optical fiber demodulator and the host are arranged in the protective box;

each anchor rod sensor comprises an anchor rod main body, a fiber bragg grating, an anchoring ring and a protection ring, wherein,

the anchor rod main body is provided with a groove along the axis direction, and the initial position of the groove is the tail end of the anchor rod main body;

the fiber bragg grating is arranged in the groove, wherein the fiber bragg grating comprises an optical fiber and a grating, and the grating is etched on the optical fiber and is arranged at equal intervals;

the protection circular ring is sleeved on the anchor rod main body at a preset distance away from the tail end of the anchor rod main body, and the anchor is arranged at the tail end of the anchor rod main body;

the anchor of one anchor rod sensor in the plurality of anchor rod sensors is welded on the outer side of the protective box body;

the optical fiber demodulator is used for respectively acquiring wavelength information detected by each anchor rod sensor and respectively demodulating the wavelength information detected by each anchor rod sensor so as to generate wavelength data corresponding to each anchor rod sensor;

and the host is used for carrying out safety assessment on the surrounding rock of the roadway according to the wavelength data corresponding to each anchor rod sensor.

2. The fiber grating sensing roadway surrounding rock safety monitoring system with the anchor rod as the sensing medium according to claim 1, wherein the host is connected with the fiber demodulation instrument through a network cable.

3. The fiber grating sensing roadway surrounding rock safety monitoring system taking the anchor rod as a sensing medium according to claim 1, wherein the length of the groove is 1.2m, the groove is a groove of 5mm x 5mm, and the length of the groove is smaller than the length of the anchor rod main body.

4. The fiber grating sensing roadway surrounding rock safety monitoring system with the anchor rod as the sensing medium according to claim 1, wherein the anchoring is mechanical anchoring.

5. The fiber grating sensing roadway surrounding rock safety monitoring system with the anchor rod as the sensing medium according to claim 1, wherein the fiber grating is adhered in the groove through epoxy resin glue.

6. The fiber bragg grating sensing roadway surrounding rock safety monitoring system with anchor rods as sensing media according to claim 1, wherein a plurality of detection holes are formed in the roadway surrounding rock, and the anchor rod sensors are respectively inserted into the detection holes; wherein the content of the first and second substances,

and the anchoring and protecting ring of the anchor rod sensor is positioned outside the detection hole.

7. The fiber bragg grating sensing roadway surrounding rock safety monitoring system taking anchor rods as sensing media according to claim 1, wherein one optical fiber is led out from the tail end of each anchor rod main body, the led-out optical fiber is connected with the optical fiber demodulator through the anchoring, the optical fiber led out from the tail end of each anchor rod main body is respectively connected with the optical fiber demodulator, or the optical fiber led out from the tail end of each anchor rod main body is connected with the optical fiber demodulator after being connected in series.

8. The fiber grating sensing roadway surrounding rock safety monitoring system with the anchor rod as the sensing medium according to claim 1, wherein the inner diameter of the protection ring is 20mm, the outer diameter of the protection ring is 45mm, and the thickness of the protection ring is 30 mm.

9. The fiber grating sensing roadway surrounding rock safety monitoring system with the anchor rod as the sensing medium according to claim 1, wherein the host comprises:

the first acquisition module is used for acquiring wavelength data corresponding to the anchor rod sensor welded on the outer side of the protection box body and taking the wavelength data corresponding to the anchor rod sensor welded on the outer side of the protection box body as reference wavelength data;

the analysis module is used for analyzing the reference wavelength data to determine a target time period;

the second acquisition module is used for extracting target wavelength data from the wavelength data corresponding to each anchor rod sensor according to the target time period;

and the safety evaluation module is used for extracting target wavelength data from the wavelength data corresponding to each anchor rod sensor and carrying out safety evaluation on the roadway surrounding rock.

10. The fiber grating sensing roadway surrounding rock safety monitoring system with the anchor rod as the sensing medium according to claim 1, wherein the sampling rate of the fiber demodulator is 500 Hz.

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