Monitoring method for tunnel surrounding rock deformation

Abstract

The invention discloses a monitoring method for tunnel surrounding rock deformation. The monitoring method comprises the steps that a plurality of monitoring points are arranged on tunnel surrounding rock; using an image acquisition device to acquire a monitoring image of the tunnel surrounding rock at a set initial time interval; setting a short-term monitoring period, determining the displacement of each monitoring point according to the monitoring position of each monitoring point in the plurality of deformation images, carrying out statistical analysis on the displacement of each monitoring point in the monitoring period, and calculating an average deformation rate v; setting deformation rate thresholds vth1 and vth2 when the average deformation rate v meets vlt; when vth1 is greater than vth1, prolonging the initial time interval to 1.5 times of the original value; when vgt; when vth2 is detected, shortening the initial time interval to half of the original value; and when vth1 < = v < = vth2, keeping the current initial time interval unchanged. According to the invention, the monitoring efficiency of tunnel surrounding rock deformation can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a method for monitoring deformation of tunnel surrounding rocks. Background Art

[0002] In rock underground engineering, the surrounding rock mass whose stress state changes due to the influence of excavation is called surrounding rock. During the construction process or in the process of being put into use after the completion of construction, the surrounding rock of the tunnel will deform under the action of external forces, and this deformation will affect the safety of the tunnel. Therefore, it is necessary to monitor the deformation of the tunnel surrounding rock. Existing methods include laser monitoring method, image monitoring method, etc. The image monitoring method can directly collect images of the tunnel surrounding rock and obtain the deformation of the tunnel surrounding rock by analyzing the images. Compared with the laser monitoring method, the image monitoring method is more intuitive. However, the acquisition of monitoring images is collected at fixed time intervals, and the actual deformation of the tunnel surrounding rock cannot be discovered in time, and may even affect the judgment of the surrounding rock deformation. Moreover, the monitoring images are usually collected in real time and the number is huge. Therefore, the workload of image comparison and analysis is also quite large, which affects the monitoring efficiency of the deformation of the tunnel surrounding rock. Summary of the invention

[0003] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0004] An object of the present invention is to provide a method for monitoring deformation of tunnel surrounding rock, which can improve the monitoring efficiency of deformation of tunnel surrounding rock.

[0005] In order to achieve these purposes and other advantages according to the present invention, a method for monitoring deformation of surrounding rock of a tunnel is provided, comprising:

[0006] Step 1: Set up multiple monitoring points on the tunnel surrounding rock;

[0007] Step 2: using an image acquisition device to acquire a monitoring image of the tunnel surrounding rock at a set initial time interval, thereby acquiring a plurality of monitoring images sorted in time series;

[0008] Step 3: Calculate the displacement of each monitoring point according to the following method: set a short-term monitoring period, determine the displacement of each monitoring point according to the monitoring position of each monitoring point in the plurality of deformation images, perform statistical analysis on the displacement of each monitoring point within the monitoring period, and calculate the average deformation rate v. The calculation formula is: where d i is the displacement of the ith monitoring point, l is the number of monitoring points, n is the number of monitoring times in the short-term monitoring cycle, and t is the initial time interval;

[0009] Step 4: Set the deformation rate threshold v th1 and v th2 , when the calculated average deformation rate v satisfies v <v th1 When v>v th2 , shorten the initial time interval to half of the original value, and re-execute steps 2 to 3; when v th1 ≤v≤v th2 , keep the current initial time interval unchanged.

[0010] Preferably, in the method for monitoring deformation of tunnel surrounding rock, in step 1, a plurality of humidity sensors are installed on the tunnel surrounding rock, wherein the plurality of humidity sensors are arranged at the bottom and side walls of the tunnel, 1-2 meters from the ground, and one is installed every 50 meters; in step 2, the humidity value inside the tunnel surrounding rock is collected by the plurality of humidity sensors; in step 4, a rainfall threshold R is set according to the climate characteristics and geological conditions of the tunnel location. th When the humidity value detected by the humidity sensor exceeds a humidity threshold, and the rainfall R obtained by the rainfall calculation model R=f(H), where H is the humidity, exceeds R th , then the time interval shortening mechanism is triggered, the initial time interval is adjusted to the shortest interval, and steps 2 to 3 are executed again.

[0011] Preferably, in the method for monitoring deformation of tunnel surrounding rock, in step 1, a seismic monitor is installed on the tunnel surrounding rock, and the seismic monitor is installed at a relatively stable position in the tunnel; in step 2, a seismic wave signal is detected by the seismic monitor; in step 4, when the magnitude M of the seismic wave detected by the seismic monitor exceeds a set magnitude threshold M th , shorten the initial time interval to 1 hour, and re-execute steps 2 to 3.

[0012] Preferably, in the method for monitoring deformation of tunnel surrounding rock, in step 4, when the calculated average deformation rate v satisfies v <v th1 When the rainfall R does not exceed R th1 , but more than R th2 , where R th1 Greater than R th2 , and R th1 For R th 50-60% of R th2 For R th If the initial time interval is 20-30% of the original value, the initial time interval is shortened to 0.5-0.8 times of the original value, and steps 2 to 3 are executed again.

[0013] Preferably, the monitoring method for tunnel surrounding rock deformation further includes: step 5, using an image acquisition device to acquire a standard image of the tunnel surrounding rock, the standard image including the multiple monitoring points; step 6, identifying the multiple monitoring points from the standard image and marking the standard position of each monitoring point, identifying the multiple monitoring points from each monitoring image and marking the monitoring position of each monitoring point, comparing the multiple monitoring images with the standard image in the time sequence of acquisition, extracting a number of monitoring points from each monitoring image when comparing each monitoring image with the standard image, comparing the monitoring positions of the extracted monitoring points with the standard positions of the corresponding monitoring points in the standard image, the monitoring points extracted for comparison from two adjacent monitoring images in the time sequence are different, and within a set time period The monitoring points extracted from the several monitoring images in the standard image for comparison include the multiple monitoring points. When the monitoring position of any monitoring point in one of the monitoring images deviates from the standard position of the corresponding monitoring point in the standard image, it is determined that the tunnel surrounding rock is deformed, and the corresponding monitoring image is set as the deformation starting image, and the monitoring image that is arranged after the deformation starting image in time sequence among the multiple monitoring images is set as the deformed image; step seven, comparing the several deformed images with the standard image in time sequence respectively, when comparing each deformed image with the standard image, comparing the monitoring positions of the multiple monitoring points in each deformed image with the standard positions of the multiple monitoring points in the standard image, and determining the offset between the monitoring position of each monitoring point in each deformed image and the standard position of the corresponding monitoring point.

[0014] Preferably, in the monitoring method for tunnel surrounding rock deformation, in the step one, an identification tag is set at each monitoring point; in the step two, the monitoring image contains the identification tags of the multiple monitoring points; in the step five, the standard image contains the identification tags of the multiple monitoring points; in the step six, when the multiple monitoring points are identified from the standard image and the standard position of each monitoring point is marked, the standard position of each monitoring point is determined by identifying the identification tag of each monitoring point from the standard image; when the multiple monitoring points are identified from each monitoring image and the monitoring position of each monitoring point is marked, the monitoring position of each monitoring point is determined by identifying the identification tag of each monitoring point from the monitoring image.

[0015] Preferably, in the method for monitoring deformation of tunnel surrounding rock, the identification label is a circular pattern painted with a number.

[0016] Preferably, in the monitoring method for tunnel surrounding rock deformation, in the step one, the multiple monitoring points are numbered in sequence according to their spatial positions; in the step six, the multiple monitoring points are identified from the standard image, and the number of each monitoring point is marked; the multiple monitoring points are identified from each monitoring image, and the number of each monitoring point is marked; when comparing each monitoring image with the standard image, a number of monitoring points are extracted from each monitoring image, and the numbers of the extracted monitoring points are not adjacent; when comparing the monitoring positions of the extracted monitoring points with the standard positions of the corresponding monitoring points in the standard image, the monitoring positions of the extracted monitoring points are compared with the standard positions of the monitoring points with the corresponding numbers in the standard image according to the numbering order of the extracted monitoring points.

[0017] Preferably, in the monitoring method for tunnel surrounding rock deformation, in step seven, after determining the offset between the monitoring position of each monitoring point in each deformed image relative to the standard position of the corresponding monitoring point, the offset path of the same monitoring point in the several deformed images relative to the corresponding monitoring point in the standard image is determined, the multiple monitoring points in the standard image are connected into a standard line, the multiple monitoring points in each deformed image are connected into a monitoring line, and the offset of the monitoring line relative to the standard line is recorded.

[0018] The present invention has at least the following beneficial effects:

[0019] The present invention provides a method for monitoring deformation of tunnel surrounding rock, comprising: a method for monitoring deformation of tunnel surrounding rock, comprising: step 1, setting a plurality of monitoring points on the tunnel surrounding rock; step 2, using an image acquisition device to acquire a monitoring image of the tunnel surrounding rock at a set initial time interval, thereby acquiring a plurality of monitoring images sorted in time series; step 3, calculating the displacement of each monitoring point according to the following method: setting a short-term monitoring cycle, determining the displacement of each monitoring point according to the monitoring position of each monitoring point in the plurality of deformation images, performing statistical analysis on the displacement of each monitoring point within the monitoring cycle, and calculating an average deformation rate v, the calculation formula is where d i is the displacement of the ith monitoring point, l is the number of monitoring points, n is the number of monitoring times in the short-term monitoring cycle, and t is the initial time interval; Step 4: Set the deformation rate threshold v th1 and v th2 , when the calculated average deformation rate v satisfies v <v th1 When v>v th2, shorten the initial time interval to half of the original value, and re-execute steps 2 to 3; when v th1 ≤v≤v th2 , keep the current initial time interval unchanged. The present invention can dynamically adjust the time interval of image acquisition according to the deformation of the tunnel surrounding rock, thereby timely discovering the deformation of the tunnel surrounding rock, while avoiding increasing the workload of image processing and analysis, and can improve the monitoring efficiency of the tunnel surrounding rock. When the present invention makes an initial judgment on whether the tunnel surrounding rock is deformed, it does not directly compare all the monitoring points collected by each monitoring image with the standard image, but extracts a part of the monitoring points for comparison. After determining that the tunnel surrounding rock has deformed, the starting time of the deformation is determined, and then all the monitoring points involved in the deformed image after the deformation starting point image are compared with the standard image, thereby greatly reducing the workload of data analysis and processing, reducing the complexity and difficulty of data processing, and thus improving the monitoring efficiency of the tunnel surrounding rock deformation.

[0020] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flowchart of a method for monitoring deformation of surrounding rock of a tunnel according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0023] like Figure 1 As shown, an embodiment of the present invention provides a monitoring method for tunnel surrounding rock deformation, including: a monitoring method for tunnel surrounding rock deformation, including: step one, setting multiple monitoring points on the tunnel surrounding rock; step two, using an image acquisition device to acquire a monitoring image of the tunnel surrounding rock at a set initial time interval, thereby acquiring multiple monitoring images sorted in time series; step three, calculating the displacement of each monitoring point according to the following method: setting a short-term monitoring period, determining the displacement of each monitoring point according to the monitoring position of each monitoring point in the several deformation images, performing statistical analysis on the displacement of each monitoring point within the monitoring period, and calculating the average deformation rate v, the calculation formula is where d i is the displacement of the ith monitoring point, l is the number of monitoring points, n is the number of monitoring times in the short-term monitoring cycle, and t is the initial time interval; Step 4: Set the deformation rate threshold v th1 and v th2, when the calculated average deformation rate v satisfies v <v th1 When v>v th2 , shorten the initial time interval to half of the original value, and re-execute steps 2 to 3; when v th1 ≤v≤v th2 , keep the current initial time interval unchanged.

[0024] The method provided by the present invention comprises:

[0025] (1) A relatively conservative time interval is initially set. For example, for hard rock tunnels with good stability, the initial time interval can be set to 24 hours; for relatively soft surrounding rocks, it can be set to 12 hours. At the beginning, monitoring images are collected according to the initial time interval, and the images are analyzed, and the displacement changes of monitoring points in adjacent images are calculated using image processing algorithms.

[0026] (2) Set a short-term monitoring period (such as one week). During this period, the average deformation rate v is calculated by statistically analyzing the displacement data of monitoring points in multiple sets of adjacent images. The calculation formula is:

[0027] where d i is the displacement of the ith monitoring point, n is the number of monitoring times in the short-term monitoring cycle, and t is the time interval.

[0028] (3) Dynamic adjustment of initial time interval:

[0029] Adjustment based on deformation rate: Set the deformation rate threshold v th1 and v th2 , when the calculated average deformation rate v satisfies v <v th1 When the time interval is 1.5 times longer than the original one, it indicates that the surrounding rock is deforming slowly. In this case, the time interval can be appropriately extended. For example, the time interval can be extended to 1.5 times the original one to save resources and reduce the amount of data.

[0030] When v>v th2 When the deformation of the surrounding rock is accelerated, it indicates that the time interval needs to be shortened. For example, the time interval can be shortened to half of the original time interval to monitor the deformation more closely.

[0031] When v th1 ≤v≤v th2 , keep the current time interval unchanged.

[0032] In summary, the present invention can dynamically adjust the time interval of image acquisition according to the deformation of the tunnel surrounding rock, thereby timely discovering the deformation of the tunnel surrounding rock, while avoiding increasing the workload of image processing and analysis, and can improve the monitoring efficiency of the tunnel surrounding rock.

[0033] In a preferred embodiment, the method for monitoring deformation of tunnel surrounding rock, in step 1, multiple humidity sensors are installed on the tunnel surrounding rock, wherein the multiple humidity sensors are arranged at the bottom and side walls of the tunnel, 1-2 meters from the ground, and one is installed every 50 meters; in step 2, the humidity value inside the tunnel surrounding rock is collected by the multiple humidity sensors; in step 4, a rainfall threshold R is set according to the climate characteristics and geological conditions of the tunnel location. th When the humidity value detected by the humidity sensor exceeds a humidity threshold, and the rainfall R obtained by the rainfall calculation model R=f(H), where H is the humidity, exceeds R th , then the time interval shortening mechanism is triggered, the initial time interval is adjusted to the shortest interval, and steps 2 to 3 are executed again.

[0034] The humidity sensor should be a high-precision, long-term stable and anti-interference humidity sensor. Its measurement range should cover the possible humidity range in the tunnel (e.g. 0%-100% RH), and the accuracy should reach ±2% RH. A capacitive humidity sensor can be selected. Its working principle is that the capacitance value of the capacitor changes with the ambient humidity, and the humidity is determined by measuring the capacitance value. The humidity sensors are evenly distributed and installed in different locations in the tunnel, especially in areas prone to water accumulation or seepage, such as the bottom and side walls of the tunnel, 1-2 meters from the ground, and one is installed every 50 meters.

[0035] The data acquisition system is used to collect data from environmental monitoring equipment in real time and store it in the database. The sampling frequency is set according to the characteristics of different equipment. For example, the data acquisition frequency of the humidity sensor can be set to once per minute.

[0036] According to the climate characteristics and geological conditions of the tunnel location, the rainfall threshold R is set. th When the humidity value detected by the humidity sensor continues to rise, and the rainfall R obtained by the rainfall calculation model R = f(H), where H is the humidity, exceeds R th , for example R th =50 mm / h, the time interval shortening mechanism is triggered to adjust the time interval to the shortest interval (such as 1 hour).

[0037] In a preferred embodiment, the method for monitoring deformation of tunnel surrounding rock comprises the following steps: in step 1, a seismic monitor is installed on the tunnel surrounding rock, and the seismic monitor is installed at a relatively stable position in the tunnel; in step 2, a seismic wave signal is detected by the seismic monitor; in step 4, when the magnitude M of the seismic wave detected by the seismic monitor exceeds a set magnitude threshold M th , shorten the initial time interval to 1 hour, and re-execute steps 2 to 3.

[0038] The seismic monitor uses a highly sensitive seismic monitor that can detect tiny seismic wave signals, and its minimum detection magnitude can be as low as 0.1 on the Richter scale. A three-component seismometer can be used to simultaneously monitor the components of seismic waves in three directions (vertical and horizontal orthogonal directions) in order to accurately determine the direction and intensity of the earthquake. The seismic monitor is installed in a relatively stable position in the tunnel, such as the cross passage or expansion section of the tunnel, to avoid interference from construction and vehicle traffic, and to ensure that the instrument can receive seismic wave signals from different directions.

[0039] The data acquisition system collects data from environmental monitoring equipment in real time and stores it in a database. The sampling frequency is set according to the characteristics of different equipment. For example, a seismic monitor can collect data in real time and continuously according to its own sensitivity and the characteristic frequency of seismic waves.

[0040] When the magnitude M of the seismic wave detected by the seismic monitor exceeds the set magnitude threshold M th For example, M th =0.5, immediately shorten the time interval to 1 hour.

[0041] In a preferred embodiment, the method for monitoring tunnel surrounding rock deformation, in step 4, when the calculated average deformation rate v satisfies v <v th1 When the rainfall R does not exceed R th1 , but more than R th2 , where R th1 Greater than R th2 , and R th1 For R th 50-60% of R th2 For R th If the initial time interval is 20-30% of the original value, the initial time interval is shortened to 0.5-0.8 times of the original value, and steps 2 to 3 are executed again.

[0042] When the calculated average deformation rate v satisfies v <v th1 When the surrounding rock deformation is relatively slow, the time interval can be appropriately extended. For example, the time interval can be extended to 1.5 times the original time interval; but if the rainfall R does not exceed R th1 , but exceeds Rth2 , where R th1 Greater than R th2 , and R th1 For R th 50-60% of R th2 For R th If the time interval is 20-30% of the original time, the time interval is shortened to 0.5-0.8 times the original time.

[0043] In a preferred embodiment, the monitoring method for tunnel surrounding rock deformation also includes: step 5, using an image acquisition device to acquire a standard image of the tunnel surrounding rock, the standard image containing the multiple monitoring points; step 6, identifying the multiple monitoring points from the standard image and marking the standard position of each monitoring point, identifying the multiple monitoring points from each monitoring image and marking the monitoring position of each monitoring point, comparing the multiple monitoring images with the standard image in the time sequence of acquisition, extracting a number of monitoring points from each monitoring image when comparing each monitoring image with the standard image, comparing the monitoring positions of the extracted monitoring points with the standard positions of the corresponding monitoring points in the standard image, and extracting different monitoring points for comparison from two adjacent monitoring images in time sequence. The monitoring points for comparison extracted from several monitoring images within the time period include the multiple monitoring points. When the monitoring position of any monitoring point in one of the monitoring images deviates from the standard position of the corresponding monitoring point in the standard image, it is determined that the tunnel surrounding rock is deformed, and the corresponding monitoring image is set as the deformation starting image, and the monitoring image that is arranged after the deformation starting image in time sequence among the multiple monitoring images is set as the deformed image; step seven, comparing the several deformed images with the standard image in time sequence respectively, when comparing each deformed image with the standard image, comparing the monitoring positions of the multiple monitoring points in each deformed image with the standard positions of the multiple monitoring points in the standard image, and determining the offset between the monitoring position of each monitoring point in each deformed image and the standard position of the corresponding monitoring point.

[0044] The standard image is collected when it is determined that the tunnel has not deformed, for example, it can be collected just after the tunnel is constructed or surveyed. The monitoring image is collected during the tunnel construction process or when the tunnel is put into use, and is used to monitor whether the tunnel is deformed and the deformation situation. The image acquisition device collects the monitoring image according to the set initial time interval, and the initial time interval can be set as needed.

[0045] When making an initial judgment on deformation, a part of monitoring points is extracted from each monitoring image. When compared with the standard image, the monitoring positions of the extracted monitoring points are compared with the standard positions of the corresponding monitoring points in the standard image. If the monitoring positions of all the extracted monitoring points in the monitoring image are consistent with the standard positions of the corresponding monitoring points in the standard image, it means that the tunnel surrounding rock has not deformed at the time when the monitoring image is collected. Then continue the comparison of the next monitoring image. When the monitoring position of a certain monitoring point extracted in the monitoring image does not coincide with the standard image of the corresponding monitoring point in the standard image in the comparison of the next monitoring image and the standard image, but deviates, it means that the tunnel surrounding rock has deformed at the time when the monitoring image is collected. At this time, the monitoring image can be set as the deformation starting point image, and the time when the monitoring image is collected is set as the time when the tunnel surrounding rock deforms. In the above process, only a part of the monitoring points are extracted from each monitoring image for comparison, which can greatly reduce the workload of data analysis, thereby reducing the difficulty and complexity of data processing, and ultimately improving monitoring efficiency. In order to reduce the workload of data analysis, the monitoring points extracted from two adjacent monitoring images in time are not repeated. In other words, if a monitoring point has been analyzed in the previous monitoring image and the monitoring point has not deviated, the possibility of deviation in the next monitoring image is small. Therefore, the monitoring point can be extracted without duplication in the next monitoring point. However, in order to avoid missed judgments as much as possible, the monitoring points extracted from several monitoring images in a set time period need to cover all monitoring points. The time period can be determined according to the length of time that the tunnel surrounding rock may change its center, or designed according to actual needs.

[0046] Through the above operation, when making an initial judgment on whether the tunnel surrounding rock is deformed, the present invention does not directly compare all the monitoring points collected by each monitoring image with the standard image, but extracts a part of the monitoring points for comparison. After determining that the tunnel surrounding rock has deformed, the starting time of the deformation is determined, and then all the monitoring points involved in the deformation image after the deformation starting point image are compared with the standard image, thereby greatly reducing the workload of data analysis and processing, reducing the complexity and difficulty of data processing, and thus improving the monitoring efficiency of tunnel surrounding rock deformation.

[0047] In a preferred embodiment, in the monitoring method for tunnel surrounding rock deformation, in the step one, an identification tag is set at each monitoring point; in the step two, the monitoring image contains the identification tags of the multiple monitoring points; in the step five, the standard image contains the identification tags of the multiple monitoring points; in the step six, when the multiple monitoring points are identified from the standard image and the standard position of each monitoring point is marked, the standard position of each monitoring point is determined by identifying the identification tag of each monitoring point from the standard image; when the multiple monitoring points are identified from each monitoring image and the monitoring position of each monitoring point is marked, the monitoring position of each monitoring point is determined by identifying the identification tag of each monitoring point from the monitoring image.

[0048] When recognizing standard images or monitoring images, it is necessary to identify monitoring points from these images. In tunnels, the light is poor and the image quality is average, which will also affect the efficiency of image recognition. In order to solve this problem, identification tags are set on the monitoring points. During the image processing process, these identification tags will be directly identified from the image, so that the monitoring points can be found quickly.

[0049] In a preferred embodiment, in the method for monitoring deformation of surrounding rock of a tunnel, the identification label is a circular pattern painted with a number. The circular pattern can be red to facilitate identification and improve the efficiency of image processing.

[0050] In a preferred embodiment, in the monitoring method for tunnel surrounding rock deformation, in the step one, the multiple monitoring points are numbered in sequence according to their spatial positions; in the step two or four, the multiple monitoring points are identified from the standard image, and the number of each monitoring point is marked; the multiple monitoring points are identified from each monitoring image, and the number of each monitoring point is marked; when comparing each monitoring image with the standard image, a number of monitoring points are extracted from each monitoring image, and the numbers of the extracted monitoring points are not adjacent; when comparing the monitoring positions of the extracted monitoring points with the standard positions of the corresponding monitoring points in the standard image, the monitoring positions of the extracted monitoring points are compared with the standard positions of the monitoring points with the corresponding numbers in the standard image according to the numbering order of the extracted monitoring points.

[0051] When setting the monitoring points, numbers can be set according to the spatial distribution of the monitoring points along the tunnel. The numbers are painted on the monitoring points as identification labels. When performing image processing, the numbers can be directly identified from the image, so as to directly determine the number of each identified monitoring point. There is no need to check one by one in the later stage to see which monitoring point in the standard image each monitoring point identified in the monitoring image corresponds to. As long as two monitoring points have the same number, they are the same monitoring point. This design can improve the efficiency of data processing.

[0052] In a preferred embodiment, in the monitoring method for tunnel surrounding rock deformation, in the step four, extracting a number of monitoring points from each monitoring image includes: extracting one monitoring point from the multiple monitoring points in each monitoring image at intervals of 1 to 5 monitoring points according to spatial positions.

[0053] In a preferred embodiment, in the method for monitoring deformation of tunnel surrounding rock, the set time period is 7 to 15 days.

[0054] This time period can be determined based on the length of time it takes for the tunnel surrounding rock to change center.

[0055] In a preferred embodiment, in the monitoring method for tunnel surrounding rock deformation, in step seven, after determining the offset between the monitoring position of each monitoring point in each deformed image relative to the standard position of the corresponding monitoring point, the offset path of the same monitoring point in the several deformed images relative to the corresponding monitoring point in the standard image is determined, the multiple monitoring points in the standard image are connected into a standard line, the multiple monitoring points in each deformed image are connected into a monitoring line, and the offset of the monitoring line relative to the standard line is recorded.

[0056] The monitoring position of the same monitoring point in each deformation image can be marked in the standard image, so that the displacement path of the same monitoring point over time can be intuitively seen, and the displacement path also reflects the deformation of the tunnel surrounding rock. In addition, multiple monitoring points in each deformation image can be connected to form a monitoring line, and multiple monitoring lines can be marked on the standard image. Compared with the standard line, the deformation of the tunnel surrounding rock can be more intuitively understood.

[0057] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A method for monitoring deformation of tunnel surrounding rock, characterized in that: include: Step 1: Set up multiple monitoring points on the tunnel surrounding rock; Step 2: using an image acquisition device to acquire a monitoring image of the tunnel surrounding rock at a set initial time interval, thereby acquiring a plurality of monitoring images sorted in time series; Step 3: Calculate the displacement of each monitoring point according to the following method: set a short-term monitoring period, determine the displacement of each monitoring point according to the monitoring position of each monitoring point in the plurality of deformation images, perform statistical analysis on the displacement of each monitoring point within the monitoring period, and calculate the average deformation rate v. The calculation formula is: where d i is the displacement of the ith monitoring point, l is the number of monitoring points, n is the number of monitoring times in the short-term monitoring cycle, and t is the initial time interval; Step 4: Set the deformation rate threshold v th1 and v th2 , when the calculated average deformation rate v satisfies v <v th1 When v>v th2 , shorten the initial time interval to half of the original value, and re-execute steps 2 to 3; when v th1 ≤v≤v th2 , keep the current initial time interval unchanged.

2. The method for monitoring deformation of tunnel surrounding rock according to claim 1, characterized in that: In the step 1, a plurality of humidity sensors are installed on the tunnel surrounding rock, wherein the plurality of humidity sensors are arranged at the bottom and side walls of the tunnel, 1-2 meters from the ground, and one is installed every 50 meters; in the step 2, the humidity value inside the tunnel surrounding rock is collected by the plurality of humidity sensors; in the step 4, a rainfall threshold R is set according to the climate characteristics and geological conditions of the tunnel location. th When the humidity value detected by the humidity sensor exceeds a humidity threshold, and the rainfall R obtained by the rainfall calculation model R=f(H), where H is the humidity, exceeds R th , then the time interval shortening mechanism is triggered, the initial time interval is adjusted to the shortest interval, and steps 2 to 3 are executed again.

3. The method for monitoring deformation of tunnel surrounding rock according to claim 1, characterized in that: In the step 1, a seismic monitor is installed on the surrounding rock of the tunnel, and the seismic monitor is installed at a relatively stable position in the tunnel; in the step 2, a seismic wave signal is detected by the seismic monitor; in the step 4, when the magnitude M of the seismic wave detected by the seismic monitor exceeds the set magnitude threshold M th , shorten the initial time interval to 1 hour, and re-execute steps 2 to 3.

4. The method for monitoring deformation of tunnel surrounding rock according to claim 3, characterized in that: In step 4, when the calculated average deformation rate v satisfies v <v th1 When the rainfall R does not exceed R th1 , but more than R th2 , where R th1 Greater than R th2 , and R th1 For R th 50-60% of R th2 For R th If the initial time interval is 20-30% of the original value, the initial time interval is shortened to 0.5-0.8 times of the original value, and steps 2 to 3 are executed again.

5. The method for monitoring deformation of tunnel surrounding rock according to claim 1, characterized in that: It also includes: step 5, using an image acquisition device to acquire a standard image of the tunnel surrounding rock, the standard image containing the multiple monitoring points; step 6, identifying the multiple monitoring points from the standard image and marking the standard position of each monitoring point, identifying the multiple monitoring points from each monitoring image and marking the monitoring position of each monitoring point, comparing the multiple monitoring images with the standard image in the time sequence of acquisition, extracting a number of monitoring points from each monitoring image when comparing each monitoring image with the standard image, comparing the monitoring positions of the extracted monitoring points with the standard positions of the corresponding monitoring points in the standard image, the monitoring points extracted for comparison from two adjacent monitoring images in the time sequence are different, and the monitoring points extracted from a number of monitoring images within a set time period are different. The monitoring points for comparison include the multiple monitoring points. When the monitoring position of any monitoring point in one of the monitoring images deviates from the standard position of the corresponding monitoring point in the standard image, it is determined that the tunnel surrounding rock is deformed, and the corresponding monitoring image is set as the deformation starting point image, and the monitoring image that is arranged after the deformation starting point image in time sequence among the multiple monitoring images is set as the deformed image; step seven, comparing several deformed images with the standard image in time sequence respectively, when comparing each deformed image with the standard image, comparing the monitoring positions of the multiple monitoring points in each deformed image with the standard positions of the multiple monitoring points in the standard image, and determining the offset between the monitoring position of each monitoring point in each deformed image and the standard position of the corresponding monitoring point.

6. The method for monitoring deformation of tunnel surrounding rock according to claim 5, characterized in that: In the step one, an identification tag is set at each monitoring point; in the step two, the monitoring image contains the identification tags of the multiple monitoring points; in the step five, the standard image contains the identification tags of the multiple monitoring points; in the step six, when the multiple monitoring points are identified from the standard image and the standard position of each monitoring point is marked, the standard position of each monitoring point is determined by identifying the identification tag of each monitoring point from the standard image; when the multiple monitoring points are identified from each monitoring image and the monitoring position of each monitoring point is marked, the monitoring position of each monitoring point is determined by identifying the identification tag of each monitoring point from the monitoring image.

7. The method for monitoring deformation of tunnel surrounding rock according to claim 6, characterized in that: The identification label is a circular pattern painted with a number.

8. The method for monitoring deformation of tunnel surrounding rock according to claim 7, characterized in that: In the step one, the multiple monitoring points are numbered in sequence according to their spatial positions; in the step six, the multiple monitoring points are identified from the standard image and the number of each monitoring point is marked; the multiple monitoring points are identified from each monitoring image and the number of each monitoring point is marked; when comparing each monitoring image with the standard image, a number of monitoring points are extracted from each monitoring image, and the numbers of the extracted monitoring points are not adjacent; when comparing the monitoring positions of the extracted monitoring points with the standard positions of the corresponding monitoring points in the standard image, the monitoring positions of the extracted monitoring points are compared with the standard positions of the monitoring points with corresponding numbers in the standard image according to the numbering order of the extracted monitoring points.

9. The method for monitoring deformation of tunnel surrounding rock according to claim 8, characterized in that: In the step seven, after determining the offset between the monitoring position of each monitoring point in each deformed image and the standard position of the corresponding monitoring point, determine the offset path of the same monitoring point in the several deformed images relative to the corresponding monitoring point in the standard image, connect the multiple monitoring points in the standard image into a standard line, connect the multiple monitoring points in each deformed image into a monitoring line, and record the offset of the monitoring line relative to the standard line.

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