CN210981177U - Intelligent geogrid suitable for tunnel and monitoring system thereof - Google Patents

Abstract

The utility model belongs to the technical field of tunnel engineering safety monitoring and protection, and discloses an intelligent geogrid suitable for a tunnel and a monitoring system thereof, wherein the intelligent geogrid comprises a first geogrid, a second geogrid and a mixed optical fiber, the mixed optical fiber is pasted on the outer surface of the first geogrid, the second geogrid is connected with the first geogrid to form a geogrid body, the mixed optical fiber is positioned inside the geogrid body, the mixed optical fiber comprises strain optical fibers and temperature optical fibers, four corners of the geogrid body are respectively provided with grouting holes, and the geogrid body is paved in tunnel surrounding rocks; the monitoring system of the intelligent geogrid comprises a transmission optical cable, a demodulator and the intelligent geogrid, wherein the transmission optical cable is respectively connected with the hybrid optical fiber and the demodulator. The utility model provides a be applicable to the geogrid later stage secondary reinforcement difficulty in tunnel among the prior art, the problem that the deformation position of tunnel country rock is difficult to pinpoint.

Description

An intelligent geogrid suitable for tunnel and its monitoring system

technical field

The utility model relates to the technical field of tunnel engineering safety monitoring and protection, in particular to an intelligent geogrid suitable for tunnels and a monitoring system thereof.

Background technique

In the field of tunnel engineering safety monitoring and protection, in order to ensure the normal construction and operation of the tunnel during the construction period, the tunnel structure, especially the aquifer and broken zone, must be supported and monitored to determine the health of the tunnel. The current support technology mainly uses bolts combined with cement mortar and lining for support. The monitoring technology mainly relies on traditional monitoring methods, using total station, level and electrical sensors to monitor the tunnel. Traditional support and monitoring methods Often cannot be effectively supported and monitored in real time.

The existing tunnel reinforcement methods, especially for the local broken zone with high water content, generally use the grouting method and use geogrid to assist reinforcement, so that the tunnel can be reinforced in a short period of time, but in the subsequent construction process and operation process. , If secondary damage occurs, maintenance and reinforcement are difficult and costly. In addition, the existing geogrid cannot accurately locate the deformation position of the surrounding rock of the tunnel, which is not conducive to the health monitoring and restoration during the later operation of the geogrid.

Utility model content

By providing an intelligent geogrid suitable for tunnels and a monitoring system thereof, the embodiments of the present application solve the problems in the prior art that the geogrid suitable for tunnels is difficult to reinforce at a later stage, and the deformation position of the surrounding rock of the tunnel is difficult to accurately locate. question.

The embodiment of the present application provides an intelligent geogrid suitable for tunnels, comprising a first geogrid, a second geogrid, and a hybrid optical fiber; the hybrid optical fiber is pasted on the outer surface of the first geogrid , the second geogrid is connected with the first geogrid to form a geogrid body, and the hybrid optical fiber is located inside the geogrid body; the hybrid optical fiber includes a strain fiber and a temperature fiber; Four corners of the geogrid body are respectively provided with grouting holes; the geogrid body is laid in the surrounding rock of the tunnel.

Preferably, the geogrid body includes a plurality of parallel warp grids and a plurality of parallel weft grids.

Preferably, the hybrid optical fiber is adhered to the outer surface of the first geogrid by epoxy resin, and a PVC pipe is arranged outside the hybrid optical fiber, and the PVC pipe is located inside the geogrid body .

Preferably, grating strings are engraved on both the strain fiber and the temperature fiber.

Preferably, both the strained optical fiber and the temperature optical fiber are distributed optical fibers.

On the other hand, an embodiment of the present application provides a monitoring system for an intelligent geogrid suitable for tunnels, including: a transmission optical cable, a demodulator, and the above-mentioned intelligent geogrid suitable for tunnels; The hybrid optical fiber is connected, and the other end of the transmission optical cable is connected with the demodulator.

Preferably, the monitoring system for the intelligent geogrid suitable for tunnels further comprises: a demodulator upper computer; the demodulator upper computer is in communication with the demodulator.

Preferably, the demodulator adopts a wireless fiber grating demodulator, the demodulation channel of the demodulator is multi-channel, and the demodulation rate of the demodulator is greater than 4 kHz.

Preferably, the monitoring system for the intelligent geogrid suitable for tunnels further includes: a wireless AP and a data transmission module;

The upper computer of the demodulator is arranged in the control room outside the tunnel, the data transmission module is arranged outside the tunnel or at the entrance of the tunnel, and the wireless AP is arranged in the tunnel; the upper computer of the demodulator sequentially passes the data The transmission module and the wireless AP are connected with the demodulator.

Preferably, the data transmission module includes: a wireless base station, a gigabit optical fiber, and a technological Ethernet ring network.

One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

In the embodiment of the present application, four corners of the geogrid body are respectively provided with grouting holes, and the grouting holes cooperate with the grouting pipes to strengthen the strength of the surrounding rock and improve the strength of the geogrid itself. The slurry hole can realize the secondary reinforcement of the surrounding rock. The hybrid optical fiber is arranged inside the geogrid body, and the hybrid optical fiber includes a strain optical fiber and a temperature optical fiber. The strain optical fiber can monitor the strain of the surrounding rock, and the temperature optical fiber can monitor the infiltration water of the surrounding rock.

Description of drawings

In order to illustrate the technical solutions in this embodiment more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are an embodiment of the present utility model. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of an intelligent geogrid suitable for tunnels provided by an embodiment of the present utility model;

2 is a schematic diagram of curvature calculation in an intelligent geogrid suitable for tunnels provided by an embodiment of the present utility model;

FIG. 3 is a schematic diagram of a monitoring system for an intelligent geogrid suitable for a tunnel according to an embodiment of the present invention.

Among them, 1- geogrid body, 2- strain fiber, 3- temperature fiber, 4- grouting hole, 5- grating string, 6- transmission cable, 7- demodulator, 8- demodulator host computer, 9- demodulator -Wireless AP, 10-Data transmission module.

Detailed ways

In order to better understand the above technical solutions, the above technical solutions will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1:

Embodiment 1 provides an intelligent geogrid suitable for tunnels, as shown in FIG. 1 , including: a first geogrid, a second geogrid, and a hybrid optical fiber; the hybrid optical fiber is pasted on the first geogrid. On the outer surface of the geogrid, the second geogrid is connected with the first geogrid to form a geogrid body 1 ; the hybrid optical fiber is located inside the geogrid body 1 . That is, first fix the hybrid optical fiber on one side of the geogrid, and then use the geogrid processing technology to combine the geogrid with optical fiber and the geogrid without grating into one.

The hybrid fiber includes a strain fiber 2 and a temperature fiber 3 . Both the strained fiber 2 and the temperature fiber 3 are engraved with grating strings 5 , and the two grating strings 5 are located at the same position (one of the grating strings is shown in FIG. 1 ). The strained optical fiber 2 and the temperature optical fiber 3 are both distributed optical fibers. The strained optical fiber 2 can monitor the strain of the surrounding rock, the grating string 5 of the temperature fiber 3 can monitor the seepage water of the surrounding rock, and the grating string 5 engraved on the strained optical fiber 2 can Realize the curvature monitoring of specific points of surrounding rock. The grating string 5 is made up of gratings with different wavelengths connected in series, and made after different calibrations.

The four corners of the geogrid body 1 are respectively provided with grouting holes 4; the grouting holes 4 cooperate with the grouting pipes to strengthen the strength of the surrounding rock and improve the strength of the geogrid itself. The grouting hole 4 can realize the secondary reinforcement of the surrounding rock. The geogrid body 1 is laid in the surrounding rock of the tunnel.

The geogrid body 1 includes a plurality of parallel warp grids and a plurality of parallel weft grids.

Specifically, the hybrid optical fiber is pasted on the outer surface of the first geogrid using epoxy resin, and a PVC pipe is arranged outside the hybrid optical fiber, and the PVC pipe is located on the outer surface of the geogrid body 1 . internal. The PVC pipe is used to protect the hybrid optical fiber.

Using the temperature optical fiber 3 in combination with the strained optical fiber 2 can reduce the influence of temperature on the strained optical fiber 2 and ensure the accuracy of the measurement result.

Specifically, the calculation method for calculating the strain value of the geogrid by using the strain fiber and the temperature fiber is as follows:

The strain value measured by the strain fiber is ε _Si , and the strain caused by the temperature at the same position alone is ε _Ti , directly subtracting the value ε _Ti measured by the temperature fiber at the corresponding position from the value ε _Si measured by the strain fiber is the strain at that point. Value ε _i :

The change of the value ε _Ti measured by the temperature optical fiber is mainly caused by the permeated water, and the value ε _Ti measured by the temperature optical fiber can be used to characterize the change of the permeated water.

The grating string engraved on the strained optical fiber can monitor the curvature of a specific point of the surrounding rock, and obtain the curvature information of the point by changing the wavelength. The calculation principle is as follows.

As shown in Figure 2, the length of the micro-element is s, the thickness is h, and the distance between the grating string and the neutral line of the warp grid and the weft grid is h/2. When the section bends under the action of external force, the neutral line The corresponding arc length is s, the curvature radius is r, and the arc length corresponding to the upper surface of the micro-element is s+Δs. According to the knowledge of material mechanics, we can get:

Simplified, the curvature k corresponding to the element can be obtained as:

Among them, ε represents the strain on the upper surface of the micro-element caused by bending, according to the principle of measuring the strain of the fiber grating:

Δλ=λ(1-P _e )·ε=K _e ·ε (4)

The corresponding relationship between the central wavelength change Δλ of the fiber grating attached to the surface of the micro-element and the curvature k of the micro-segment can be obtained:

It can be seen that there is a linear correspondence between the curvature and the change of the center wavelength of the fiber grating (ie, the grating string). In actual use, the curvature information of this point can be obtained through the change of the center wavelength.

It should be noted that the present utility model does not involve new algorithms or methods. The utility model designs a new geogrid suitable for tunnels. The above calculation method is only an illustration of the principle, which is known to those skilled in the art. of.

Example 2:

Embodiment 2 provides a monitoring system for an intelligent geogrid suitable for tunnels, as shown in FIG. 3 , including the intelligent geogrid suitable for tunnels provided in Embodiment 1, as well as a transmission optical cable 6, a demodulator 7, a Adjustment host computer 8, wireless AP9, data transmission module 10.

One end of the optical transmission cable 6 is connected to the hybrid optical fiber, and the other end of the optical transmission cable 6 is connected to the demodulator 7 . The upper computer 8 of the demodulator is arranged in the control room outside the tunnel, the data transmission module 10 is arranged outside the tunnel or at the entrance of the tunnel, and the wireless AP 9 is arranged in the tunnel; the upper computer 8 of the demodulator passes through in sequence The data transmission module 10 and the wireless AP 9 are connected to the demodulator 7 .

That is, the utility model uses a grouting pipe to arrange the geogrid carrying the strained optical fiber 2 and the temperature optical fiber 3 on the tunnel wall, and transmits the laid strain optical fiber 2 and the temperature optical fiber 3 through the transmission The optical cable 6 is connected to the optical fiber monitoring part.

Specifically, the data transmission module 10 includes: a wireless base station, a gigabit optical fiber, and a technological Ethernet ring network. The long-distance transmission in the tunnel through the wireless AP9 saves a lot of cost of signal transmission.

The demodulator 7 adopts a wireless fiber grating demodulator, the demodulation channel of the demodulator 7 is multi-channel, the demodulation rate of the demodulator 7 is greater than 4kHz, and the built-in 2.4GHz wireless transmission module. The demodulator 7 is used to calculate the wavelength change, and the high-speed and high-precision fiber grating demodulator is used for high transmission speed and high measurement accuracy, which can meet the measurement requirements for wavelength signals.

The demodulation host computer 8 is used to process the wavelength, and obtain the strain size and specific point deformation through the calculation of the relevant algorithm. The algorithm may use a general algorithm in the prior art.

In summary, the intelligent geogrid monitoring system suitable for tunnels provided by the utility model realizes the combination of the installation of the geogrid and the automatic grouting technology through the grouting holes left on the geogrid, and at the same time, the geogrid is arranged on the The distributed optical fiber can monitor the mechanical state and deformation of the tunnel wall in real time, and transmit the monitoring data to the demodulator through the transmission cable. The demodulator decodes and reads the monitoring data, and the decoded data passes through the wireless AP and data transmission. The module is transmitted to the upper computer of the demodulator, and the upper computer of the demodulator analyzes and judges the monitoring data in real time, and locates the monitoring data. If the tunnel state is unstable or the deformation is too large, an early warning will be issued. The utility model overcomes many deficiencies and limitations of traditional manual detection methods and traditional sensors, and has the advantages of accuracy, stability, high efficiency and timeliness, small size and light weight, long optical fiber life, small maintenance workload in the later period, and reduced monitoring costs. , suitable for large-scale promotion and application.

Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to examples, those of ordinary skill in the art should The technical solutions can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be included in the scope of the claims of the present invention.

Claims (10)

1. An intelligent geogrid suitable for use in a tunnel, comprising: a first geogrid, a second geogrid, and a hybrid fiber; the mixed optical fiber is adhered to the outer surface of the first geogrid, the second geogrid is connected with the first geogrid to form a geogrid body, and the mixed optical fiber is located inside the geogrid body; the hybrid optical fiber comprises a strain optical fiber and a temperature optical fiber; grouting holes are respectively formed in four corners of the geogrid body; the geogrid body is laid in the tunnel surrounding rock.

2. The intelligent geogrid suitable for use in a tunnel according to claim 1, wherein the geogrid body includes a plurality of parallel warp grids and a plurality of parallel weft grids.

3. The intelligent geogrid suitable for a tunnel according to claim 1, wherein the hybrid optical fiber is adhered to the outer surface of the first geogrid through epoxy resin, a PVC pipe is arranged outside the hybrid optical fiber, and the PVC pipe is located inside the geogrid body.

4. The intelligent geogrid suitable for tunnels according to claim 1, wherein the strain optical fiber and the temperature optical fiber are both engraved with grating strings.

5. The intelligent geogrid suitable for use in a tunnel according to claim 1, wherein the strain optical fiber and the temperature optical fiber are both distributed optical fibers.

6. A monitoring system suitable for an intelligent geogrid for a tunnel, comprising: a transmission cable, a detuner, an intelligent geogrid suitable for use in tunnels according to any of claims 1-5; one end of the transmission optical cable is connected with the hybrid optical fiber, and the other end of the transmission optical cable is connected with the demodulator.

7. The monitoring system for an intelligent geogrid suitable for use in a tunnel according to claim 6, further comprising: a demodulator upper computer; and the upper computer of the demodulation instrument is communicated with the demodulation instrument.

8. The monitoring system of intelligent geogrid suitable for tunnel according to claim 6, wherein the demodulator is a wireless fiber grating demodulator, the demodulation channel of the demodulator is multi-channel, and the demodulation rate of the demodulator is greater than 4 kHz.

9. The monitoring system for an intelligent geogrid suitable for use in a tunnel according to claim 7, further comprising: the wireless AP and the data transmission module;

the demodulator upper computer is arranged in a control room outside the tunnel, the data transmission module is arranged outside the tunnel or at the tunnel opening, and the wireless AP is arranged in the tunnel; the upper computer of the demodulation instrument is connected with the demodulation instrument sequentially through the data transmission module and the wireless AP.

10. The monitoring system of an intelligent geogrid suitable for use in a tunnel according to claim 9, wherein the data transmission module comprises: wireless base station, gigabit fiber, and technical Ethernet ring.

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