Method and apparatus for quickly determining deformation trend in tunnel monitoring measurements

Abstract

A method for quickly determining a deformation trend in tunnel monitoring measurements, which method relates to the field of tunnel construction. The method comprises the following steps: arranging monitoring points; installing detection instruments at locations having good line-of-sight to the monitoring points, and collecting convergence deformation data; analyzing the convergence deformation data obtained from three consecutive collections, so as to obtain a deformation trend; and formulating construction measures on the basis of the deformation trend. Also disclosed is an apparatus for quickly determining a deformation trend in tunnel monitoring measurements.

Description

A method and device for quickly determining deformation trends in tunnel monitoring and measurement

[0001] Related applications

[0002] This application claims priority to the Chinese invention patent application with application number 202311735596.5 filed on December 16, 2023, and cites the entire contents disclosed in the above patent application as part of this application. Technical Field

[0003] The present application relates to the field of tunnel construction, and more particularly to a method and device for rapidly determining deformation trends in tunnel monitoring and measurement. Background Art

[0004] Monitoring and measurement work runs throughout the entire tunnel construction process, playing a significant role in monitoring the stability of the surrounding rock and guiding design and construction. During tunnel construction, observation points must be buried in the tunnel vault, haunch, and sidewalls to monitor the convergence and deformation of the tunnel clearance, allowing for timely calculation and processing of measurement data. Related technologies require regression analysis using at least 10 observation periods. The resulting regression curve is then used to determine deformation trends and adjust construction and design parameters. However, based on this method, the conclusions are delayed, preventing timely adjustments to construction parameters. This increases the risk to tunnel construction safety and requires improvement.

[0005] Summary of the Invention

[0006] In order to be able to adjust construction parameters in a timely manner and reduce the safety risks of tunnel construction, the present application provides a method and device for quickly determining the deformation trend of tunnel monitoring measurements.

[0007] In a first aspect, the present application provides a method for quickly determining deformation trends in tunnel monitoring measurements, using the following technical solutions:

[0008] A method for rapidly determining deformation trends in tunnel monitoring measurements comprises the following steps: deploying monitoring points; installing detection instruments at locations with good visibility to the deployed monitoring points to collect convergence deformation data; analyzing the convergence deformation data collected three times in succession to obtain a deformation trend; and formulating construction measures based on the deformation trend.

[0009] By adopting the above technical solution, during tunnel construction, detection instruments are installed in locations with good visibility to monitoring points. The detection instruments collect convergence deformation data at the monitoring points. Workers analyze three consecutive convergence deformation data sets to determine deformation trends and formulate a timely inspection plan based on these trends. If the deformation trend is abnormal, this method can be used to strengthen the tunnel support structure as soon as possible to prevent and control abnormal deformation and promptly eliminate tunnel safety hazards. If the deformation trend is convergent, construction and design parameters can be optimized and adjusted in a timely manner, thereby improving the efficiency of tunnel construction safety. Compared with existing technologies, this method can determine in advance whether abnormal deformation or convergence deformation is occurring based on the deformation trend shown by some data, allowing reinforcement measures to be taken before abnormal deformation expands, reducing tunnel construction safety risks.

[0010] Optionally, at least four pieces of data are collected continuously, and the deformation trends of the first three convergence deformation data are compared with the fourth convergence deformation data to confirm the deformation trend.

[0011] By adopting the above technical solution, the deformation trend is confirmed by the convergent deformation data obtained by the fourth detection, which is conducive to eliminating errors and improving the accuracy of the deformation trend obtained from multiple sets of deformation data.

[0012] Optionally, there are several monitoring points arranged, and the deformation data required to obtain the deformation trend comes from the same monitoring point.

[0013] By adopting the above technical solution, the accuracy and reliability of measurement can be improved.

[0014] Optionally, before using the deformation data to obtain the deformation trend, data affected by error factors and external interference factors are eliminated.

[0015] By adopting the above technical solution, factors that may cause damage to the points due to external disturbances are eliminated. For example, deformation caused by collision of the points shall not be treated as deformation, which facilitates better understanding and analysis of the convergent deformation data obtained by detection.

[0016] Optionally, the difference between adjacent deformation data is compared with the deformation resolution of the detector.

[0017] By adopting the above technical solution, when the difference of the converged deformation data is smaller than the deformation resolution, the change of the converged deformation data can be processed as an error, which is helpful to eliminate the observation error of the detector.

[0018] In a second embodiment, the present application provides a device for rapidly determining deformation trends in tunnel monitoring measurements. This device, applied to a method for rapidly determining deformation trends in tunnel monitoring measurements, includes a total station and a reflector. The reflector is fixed to a monitoring point, and the crosshairs of the reflector serve as an aiming mark for instrument observation. The total station is configured to emit laser light toward the monitoring point, and the reflector is configured to reflect the laser light. The device also includes a protective device mounted on the tunnel rock wall, disposed around the outer circumference of the reflector, and configured to protect the monitoring point.

[0019] By adopting the above technical solution, during the actual operation process, by setting the protective device around the outer periphery of the reflective sheet, the gravel splashed during the construction process is not easy to hit the reflective sheet, and the reflective sheet and the monitoring point are not easily damaged, which is beneficial to improve the reflection effect of the reflective sheet and thus help improve the detection accuracy.

[0020] Optionally, the protection device includes a protection frame and a water-heating element provided on the protection frame, and the water-heating element is provided around the outer circumference of the reflective sheet.

[0021] By adopting the above technical solution, in the actual operation process, the reflective sheet used by the total station (for example, the reflective sheet used with the total station, specifically, the reflective sheet is attached to the monitoring point and is used to reflect the laser beam emitted by the total station back to the instrument, thereby helping to make accurate measurements) is generally made of metal or metal oxide. When the humidity in the air is high, water droplets are likely to condense on the surface of the reflective sheet, thereby affecting the reflective effect of the reflective sheet. By setting a water-absorbing heating element (a water-heating element), as the moisture in the air increases, the water-absorbing heating element absorbs water and generates heat, causing the temperature near the reflective sheet to rise, making it difficult for water vapor in the air to condense on the surface of the reflective sheet, thereby improving the reflective effect of the reflective sheet in a high humidity environment, thereby improving the detection accuracy. In the actual operation process, there is a lot of dust in the tunnel. When a lot of dust accumulates on the surface of the reflective sheet at a high altitude, the staff needs to rinse it with water. The water contacts the water-absorbing heating element, causing the temperature near the reflective sheet to rise, which is conducive to the evaporation of water on the surface of the reflective sheet.

[0022] Optionally, the protective frame includes a protective plate and a positioning bolt arranged on the protective plate, the positioning bolt passes through the protective plate and is fixed to the tunnel rock wall, the positioning bolt presses against the side of the protective plate away from the tunnel rock wall to position the protective plate, and an abutment plate is provided on the protective plate, and the protective plate presses against the tunnel rock wall through the abutment plate.

[0023] By adopting the above technical solution and providing the abutment plate, it is helpful to reduce the wear on the protection plate, so that the protection plate can be reused, which is helpful to reduce the construction cost.

[0024] Optionally, the abutment plate is a thermally expanding and contracting plate.

[0025] By adopting the above technical solution, as the construction work progresses, dust falls off the surface of the tunnel rock wall, causing gaps to appear between the abutment plate and the rock layer. When the surface of the reflective sheet is cleaned, the abutment plate expands due to heat and fills the gap between the abutment plate and the tunnel rock layer, making it difficult for water used to clean the reflective sheet to enter through the gap between the abutment plate and the tunnel rock wall and erode the positioning bolts.

[0026] Optionally, the protection plate is made of heat-conducting metal.

[0027] By adopting the above technical solution, the abutment plate can be expanded and pressed against the tunnel rock wall in time.

[0028] In summary, this application has at least one of the following beneficial effects:

[0029] 1. Based on the deformation trends shown by partial data, it is possible to determine in advance whether the deformation is abnormal or convergent, so that reinforcement measures can be taken before the abnormal deformation expands, reducing the safety risks of tunnel construction;

[0030] 2. Confirming the deformation trend through the data obtained from the fourth test is helpful to eliminate errors and improve the accuracy of the deformation trend obtained from multiple sets of deformation data;

[0031] 3. By setting the protective device around the outer periphery of the reflector, it is difficult for the gravel splashed during the construction process to hit the reflector, making the reflector and the monitoring point less likely to be damaged, which is beneficial to improving the reflection effect of the reflector and thus helping to improve the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] FIG1 is a flow chart of an embodiment of the present application.

[0034] FIG2 is a schematic diagram of the overall structure of an embodiment of the present application.

[0035] FIG3 is an enlarged view of portion A in FIG2 , mainly showing the structure of the protection device.

[0036] Explanation of the accompanying reference numerals: 1. Total station; 2. Reflector; 3. Protective device; 31. Protective frame; 311. Protective plate; 312. Positioning bolt; 32. Water-heating element; 321. Mounting box; 322. Quicklime block; 323. Through hole; 4. Abutment plate; 41. Thermal expansion and contraction plate. DETAILED DESCRIPTION

[0037] The present application is further described in detail below with reference to the accompanying drawings.

[0038] The present application discloses a method for rapidly determining deformation trends measured by tunnel monitoring. As shown in FIG1 , FIG2 , and FIG3 , the method includes the following steps:

[0039] Measurement preparation: several monitoring points are arranged inside the tunnel, and the reflective sheets 2 are fixed at the monitoring points. The staff sets up the total station 1 so that the several monitoring points are all within the monitoring range of the total station 1. The total station 1 is used to collect deformation observation values ​​(convergence deformation data) of the monitoring points.

[0040] Continuous collection of observation data: Verify and calibrate total station 1 to ensure that its accuracy meets monitoring requirements. After calibration, use total station 1 to observe the location of monitoring points. In this implementation, the accuracy of total station 1 is no less than 1 mm.

[0041] During the initial observation, at least two consecutive observations should be performed to determine whether the accuracy of the total station 1 meets the standard. If the accuracy meets the standard, the average of the two deformation observations is taken as the initial value. Subsequently, continuous observations are performed at the monitoring point according to the frequency required for monitoring and measurement. The total station 1 should continuously observe and collect at least four deformation observations at the same monitoring point.

[0042] Deformation Calculation: The deformation observations collected by the total station 1 include horizontal convergence observations and vault settlement observations. The horizontal convergence observation refers to the distance between two measuring points on the survey line, while the vault settlement observation refers to the elevation of the vault measuring point. The horizontal convergence deformation value for each period is equal to the difference between the distances between two adjacent convergence measurement lines, i.e., the horizontal convergence deformation value (unit: mm). The vault settlement deformation value for each period is equal to the difference between the elevations of two adjacent vault measuring points, i.e., the vault settlement deformation value (unit: mm).

[0043] Determination of deformation: Since the deformation observation value contains errors, the error of the deformation observation value cannot be greater than the accuracy of total station 1. Deformation less than the accuracy of total station 1 may be caused by the change of the deformation observation value due to observation error, and it cannot be determined that a real deformation has occurred; when the tunnel clearance convergence deformation value is greater than the accuracy of total station 1, it can be considered that the deformation calculated using the deformation observation value represents the change in tunnel clearance. For this embodiment, the accuracy of total station 1 shall not be less than 1mm. When analyzing deformation observation values, deformation less than 1mm can be treated as accidental error, and deformation greater than 1mm can be treated as deformation. When determining whether a measuring point or line has been deformed, the on-site conditions should be combined to eliminate factors that cause the point to be disturbed and damaged by external forces. For example, deformation caused by collision of the point should not be treated as deformation.

[0044] Qualitative analysis of deformation trend: Analyze the deformation observation values ​​determined by three consecutive deformations. If the deformation values ​​of three consecutive observations show convergent deformation, it can be qualitatively determined that the tunnel is in a deformation state. If the deformation values ​​of three consecutive observations show error fluctuation characteristics, the tunnel is in a stable state.

[0045] Confirmation of deformation trend: After the tunnel is qualitatively determined to be in the deformation stage through three consecutive deformation observation values, a fourth observation should be carried out and the fourth deformation observation value should be taken for confirmation. If the deformation trend from the third to the fourth period of observation is consistent with the deformation trend of the previous three periods, a final conclusion can be made on the tunnel convergence deformation. If not, observation should be continued and the judgment should be continued according to the above-mentioned deformation trend qualitative principles.

[0046] Based on the deformation trend, a construction plan can be promptly formulated. In actual operations, deformation trends can range from convergent to stable, as well as abnormal. When the deformation trend is confirmed to be abnormal, reinforcement measures are required for the tunnel support structure. When the deformation trend is confirmed to be convergent, construction and design parameters need to be promptly optimized and adjusted. When the deformation trend is stable, the current construction plan is maintained.

[0047] The implementation principle of the method for quickly determining the deformation trend of tunnel monitoring and measurement in this embodiment is: it can detect the deformation trend as early as possible using a small number of deformation observation values ​​obtained by three to four consecutive observations; and timely adjust the subsequent tunnel construction measures according to the deformation trend to prevent and control abnormal deformation as early as possible, eliminate tunnel safety hazards in a timely manner, and adjust construction measures and design parameters in time according to the convergence trend.

[0048] The present embodiment also discloses a device for quickly determining the deformation trend of tunnel monitoring and measurement. Referring to Figures 2 and 3, the device for quickly determining the deformation trend of tunnel monitoring and measurement includes a total station 1, a reflector 2, and a protective device 3; the reflector 2 is located at the monitoring point, and the crosshairs of the reflector are used as an aiming mark for detecting instrument observation. The total station 1 emits a laser to the reflector 2, and the total station 1 receives the light reflected by the reflector 2 and analyzes the light to obtain a deformation value; the protective device 3 includes a protective frame 31 and a water-heating element 32. The protective frame 31 includes a protective plate 311 and a positioning bolt 312. The protective plate 311 is U-shaped. The protective plate 311 is a heat-conducting metal plate disposed around the outer periphery of the reflective sheet 2. The projection of the reflective sheet 2 in the direction close to the total station 1 is spaced apart from the protective plate 311. Two positioning bolts 312 are provided, one on each opposite side of the reflective sheet (e.g., on two adjacent, opposite sides, such as the left and right sides). The distribution direction of the two positioning bolts 312 is perpendicular to the distribution direction of the total station 1 and the reflective sheet 2. The two positioning bolts 312 penetrate (e.g., pass through) the protective plate 311 and are fixedly connected to the tunnel rock wall. The protective plate 311 is fixed to the tunnel rock wall via the positioning bolts 312 and is used to protect the reflective sheet 2 and the monitoring point. In this embodiment, the protective plate 311 is a U-shaped steel plate, and the diameter of the positioning bolts 312 is 20 mm.

[0049] The water-heating element 32 is fixed on the protective plate 311. The water-heating element 32 includes a mounting box 321 and a quicklime block 322. The mounting box 321 is fixed on the protective plate 311. The mounting box 321 is located on the side of the protective plate 311 close to the reflector 2. The mounting box 321 is U-shaped. The mounting box 321 is arranged around the outer periphery of the reflector 2. The quicklime block 322 is located in the mounting box 321. A number of through holes 323 are opened on the mounting box 321. The number of through holes 323 enables the quicklime block 322 to contact (communicate) with the outside of the mounting box 321.

[0050] Abutment plates 4, which are thermal expansion and contraction plates 41, are fixed to the protective plate 311. These plates are located on the side of the protective plate 311 closest to the tunnel wall. The location and number of these plates correspond exactly to the location and number of positioning bolts 312, which hold the protective plate 311 in contact with the tunnel wall. Positioning bolts 312, which penetrate the protective plate 311 and the corresponding abutment plates 4 in sequence and are then driven into the tunnel wall, secure the protective plate 311 and the plates 41 in place. In this embodiment, the plates 41 are copper alloy plates.

[0051] In actual operation, when the tunnel is foggy, moisture in the air contacts the quicklime blocks 322 through the through-holes 323. The quicklime blocks 322 generate heat upon contact with the water, raising the temperature around the reflector 2. This increase in temperature makes it less likely for moisture in the air to condense on the surface of the reflector 2. As the temperature of the reflector 2 rises, the thermal expansion and contraction plates 41 expand and press against the tunnel rock wall, reducing contact between the positioning pins 312 and moisture in the air. This reduces corrosion and helps extend the service life of the positioning pins 312. Furthermore, the provision of the water-heating element 32 facilitates faster drying of the reflector 2 surface after cleaning, reducing the impact of water on detection accuracy.

[0052] The implementation principle of the device for quickly determining the deformation trend of tunnel monitoring and measurement in this embodiment is: by setting a protection device 3 to protect the monitoring point and the reflective sheet 2, it is beneficial to reduce the impact of gravel and dust in the tunnel on the reflective sheet 2, and thus it is beneficial to improve the detection accuracy and detection efficiency.

[0053] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for quickly determining deformation trends in tunnel monitoring measurements, characterized in that: The following steps are involved: A. Set up monitoring points; B. Place the detection instrument in a place with good visibility to the monitoring point to collect convergence deformation data; C. Analyze the convergent deformation data collected three times in succession to obtain the deformation trend; as well as D. Develop construction measures based on deformation trends.

2. A method for rapidly determining deformation trend of tunnel monitoring measurement according to claim 1, characterized in that: At least four convergence deformation data are collected continuously, and the deformation trends of the first three convergence deformation data are compared with the fourth convergence deformation data.

3. A method for rapidly determining deformation trend of tunnel monitoring measurement according to claim 1, characterized in that: There are several monitoring points arranged, and the convergent deformation data required to obtain the deformation trend are collected from the same monitoring points.

4. A method for rapidly determining deformation trend of tunnel monitoring measurement according to claim 3, characterized in that: Before using the convergent deformation data to obtain the deformation trend, the convergent deformation data affected by error factors and external interference factors are eliminated.

5. The method for quickly determining deformation trend of tunnel monitoring measurement according to claim 1, characterized in that: The difference between the adjacent convergence deformation data is compared with the accuracy of the detector.

6. A device for quickly determining deformation trends of tunnel monitoring measurements, applied to a method for quickly determining deformation trends of tunnel monitoring measurements as described in any one of claims 1 to 5, comprising a total station and a reflector, wherein the reflector is fixed on a monitoring point, the crosshairs of the reflector are used as aiming marks for detecting instrument observation, the total station is used to emit lasers to the monitoring points, and the reflector is used to reflect the lasers emitted by the total station, characterized in that: It also includes a protection device, which is installed on the rock wall of the tunnel and is arranged around the outer circumference of the reflector. The protection device is used to protect the monitoring point.

7. The device for quickly determining deformation trend of tunnel monitoring measurement according to claim 6, characterized in that: The protection device comprises a protection frame and a water-heating component arranged on the protection frame, and the water-heating component is arranged around the outer circumference of the reflection sheet.

8. The device for quickly determining deformation trend of tunnel monitoring measurement according to claim 7, characterized in that: The protection frame includes a protection plate and a positioning bolt arranged on the protection plate, the positioning bolt passes through the protection plate and is fixed to the tunnel rock wall, the positioning bolt presses against the side of the protection plate away from the tunnel rock wall to position the protection plate, and an abutment plate is provided on the protection plate, and the protection plate presses against the tunnel rock wall through the abutment plate.

9. The device for quickly determining deformation trend of tunnel monitoring measurement according to claim 8, characterized in that: The abutment plate is a thermal expansion and contraction plate.

10. The device for quickly determining deformation trend of tunnel monitoring measurement according to claim 9, characterized in that: The material of the protection plate is heat-conducting metal.

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