Automatic monitoring and early warning device for tunnel vault sinking

Abstract

The utility model discloses an automatic monitoring and early warning device for tunnel vault sinking, which comprises a monitoring sensing unit, an information acquisition and transmission unit and a connecting mechanism, the monitoring sensing unit comprises more than one vibrating wire stay wire displacement sensor, the information acquisition and transmission unit comprises a multi-channel information acquisition instrument, and the multi-channel information acquisition instrument is connected with the connecting mechanism. The multi-channel information acquisition instrument is connected with a circuit of the vibration wire stay wire displacement sensor through a cable, the connecting mechanism comprises an induction wire and more than two lining connecting rods, and the lining connecting rods are connected with the top of a tunnel lining in the length direction of a tunnel vault. The vibrating wire stay wire displacement sensor is connected between the two lining connecting rods through an induction wire; the tunnel vault sinking monitoring system is not affected by tunnel construction and operation, the sensor is high in precision, good in performance and reliable in measurement data, the tunnel vault sinking monitoring requirement can be met, automatic monitoring and measurement can be achieved, the measurement workload can be greatly reduced, and the problems that data monitoring is not timely and the like are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of tunnel monitoring and early warning, in particular to an automatic monitoring and early warning device for tunnel vault subsidence. Background Art

[0002] During highway tunnel construction, monitoring the subsidence of the tunnel vault is a mandatory measurement, with a required accuracy of 0.5mm (when the allowable deformation is no more than 30mm) or 1mm (when the allowable deformation is greater than 30mm). During tunnel construction, pre-installed devices and measuring instruments monitor the deformation and stress state of the surrounding rock and supporting lining. Based on this information, early warnings are issued, allowing timely measures to prevent accidents. Therefore, the accuracy and timeliness of tunnel deformation measurement are directly related to the safety and progress of tunnel construction.

[0003] Currently, the instruments commonly used for tunnel deformation monitoring in my country include total stations, laser displacement sensors, static levels, wireless radar, and ultrasonic instruments. However, due to limitations in monitoring accuracy and the complex environment of tunnel construction, the implementation of laser displacement sensors and static levels is difficult. While wireless radar and ultrasonic sensors can achieve automated monitoring, they are affected by magnetic interference, noise, vibration, and other complex factors in the tunnel environment, resulting in large measurement errors. This makes vault subsidence one of the most difficult items to monitor automatically. Consequently, monitoring and measurement still rely on dedicated personnel using levels or total stations. This approach, which relies on dedicated personnel using instruments, not only increases the workload but also fails to meet the needs of real-time monitoring. Utility Model Content

[0004] Based on the current monitoring and measurement mode, the utility model proposes an automatic monitoring and early warning device for tunnel vault subsidence that meets the requirements of the specifications. It can easily realize automatic monitoring of vault subsidence and can be used during both the construction period and the operation period, promoting the development of automation technology for monitoring and measurement projects, and having significant economic benefits.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] A tunnel vault subsidence automatic monitoring and early warning device comprises a monitoring sensor unit, an information acquisition and transmission unit, and a connecting mechanism. The monitoring sensor unit comprises one or more vibrating wire displacement sensors. The information acquisition and transmission unit comprises a multi-channel information collector, which is connected to the circuit of the vibrating wire displacement sensor via a cable. The connecting mechanism comprises an induction line and two or more lining connecting rods, the lining connecting rods being connected to the top of the tunnel lining along the length of the tunnel vault. The vibrating wire displacement sensor is connected between the two lining connecting rods via the induction line.

[0007] Furthermore, the connection mechanism also includes a telescopic adjuster for adjusting the pre-stretch length of the vibrating wire displacement sensor, and the telescopic adjuster is connected in series to the sensing line.

[0008] Furthermore, an attached level adjustment bubble is provided on the sensing line to assist in adjusting the straightness.

[0009] Furthermore, the lining connecting rod includes a fixed-point expansion screw with a fixed length and a liftable screw with an adjustable length. The fixed-point expansion screw is installed on the lining at the end of the tunnel, and the liftable screw is installed on other set tunnel linings.

[0010] Furthermore, the liftable screw adopts a manual screw lifting mechanism, and a sleeve for connecting the induction line is provided at the lower end of the fixed point expansion screw and the liftable screw, and a wire fixing screw is provided on the sleeve. The induction line passes through the corresponding sleeve and is fixed by the wire fixing screw.

[0011] Furthermore, the multi-channel information collector is arranged in a chassis, a battery connected to the multi-channel information collector is provided in the chassis, the chassis is set on the inner wall of the tunnel, a wireless transmission LORA module connected to the multi-channel information collector circuit is also provided in the chassis, and an alarm is provided on the top of the chassis, and the alarm is connected to the multi-channel information collector circuit through a relay.

[0012] Furthermore, the battery is connected to an external power supply through a cable, the external power supply is connected to the battery through a charge and discharge controller, the alarm and the charge and discharge controller are connected through a rectifier, and the rectifier is respectively connected to the wireless transmission LORA module and the multi-channel information collector through cables.

[0013] The beneficial effects of the utility model are:

[0014] The utility model discloses an automatic monitoring and early warning device for tunnel vault subsidence, which is mainly composed of a monitoring sensor unit and an information acquisition and transmission unit, including a vibrating wire displacement sensor, a sensing line, a connecting mechanism multi-channel data acquisition module, a LORA transmission module, etc. The device can accurately sense the amount of deformation of the vault subsidence in real time, obtain the corresponding deformation relationship curve, and realize real-time data collection and early warning. The vibrating wire displacement sensor can avoid the influence of the tunnel construction environment and the operating environment, and the monitoring accuracy can be controlled within 1mm. The device is easy to install and provides a relatively reliable automatic monitoring and early warning solution for the vault subsidence monitoring project; the utility model also has the following advantages:

[0015] 1. This device can realize intelligent monitoring and early warning. When combined with the laser convergence shifter, it can better realize automated monitoring and measurement projects, which can greatly reduce the tedious measurement workload and solve the problem of untimely monitoring data.

[0016] 2. The device is not affected by tunnel construction and operation. The sensor has high precision and good performance. The measurement data is true and reliable, and can basically meet the requirements of tunnel vault subsidence monitoring.

[0017] 3. The device can automatically collect data, automatically alarm, and automatically push information;

[0018] 4. The device is easy to install, the required consumables are inexpensive, and it can be used during both the construction and operation periods.

[0019] Other advantages, objectives, and features of the present invention will be described in detail in the following description and, to some extent, will be apparent to those skilled in the art upon examination and study of the following or may be learned from practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0021] Figure 1 It is a planar schematic diagram of the utility model;

[0022] Figure 2 This is a schematic plan view of the utility model with an inclinometer;

[0023] Figure 3 A three-dimensional diagram of the installation of the monitoring device of the utility model;

[0024] Figure 4 This is the first installation method of the vibrating wire displacement sensor of the utility model;

[0025] Figure 5 This is the second installation method of the vibrating wire displacement sensor of the utility model;

[0026] Figure 6 This is the third installation method of the vibrating wire displacement sensor of the utility model;

[0027] Figure 7 This is the settlement deformation calculation model of this utility model;

[0028] Figure 8 It is the basic calculation model of settlement deformation of this utility model.

[0029] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0030] 1. Tunnel lining; 2. Fixed point expansion screw; 3. Casing; 301. Fixed line screw; 4. Sensing line; 5. Connector; 6. Telescopic adjuster; 7. Vibrating wire displacement sensor; 8. Cable; 9. Attached level adjustment bubble; 10. Monitoring point lift screw; 1001. Scale; 11. Lift adjustment knob; 12. Multi-channel data acquisition instrument; 13. Wireless transmission LORA module; 14. Relay; 15. Alarm; 16. Rectifier; 17. Chassis; 18. Charge and discharge controller; 19. External power supply; 20. Battery; 21. Inclinometer. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the preferred embodiments are only for illustrating the present invention and are not intended to limit the scope of protection of the present invention.

[0032] like Figure 1 、 3 As shown, an automatic monitoring and early warning device for tunnel vault subsidence includes multiple monitoring sensor units and an information acquisition and transmission unit. The monitoring sensor unit includes multiple vibrating wire displacement sensors 7 arranged along the length of the tunnel vault. The multiple vibrating wire displacement sensors 7 are interconnected by induction lines 4. The vibrating wire displacement sensors 7 are connected to the top of the tunnel lining 1 via a connecting mechanism and to the information acquisition and transmission unit via a cable 8, so that data monitored and collected by the vibrating wire displacement sensors 7 are transmitted to the information acquisition and transmission unit for processing. The information acquisition and transmission unit includes a multi-channel information collector 12 connected to the vibrating wire displacement sensors 7 circuits. The multi-channel information collector 12 is disposed in a chassis 17, and a battery 20 connected to the multi-channel information collector 12 is disposed in the chassis 17.

[0033] A vibrating wire sensor is a non-electrical sensor that measures non-electrical quantities. It consists of a heat-treated vibrating wire detection element and a stress-relieved spring connected to the wire at one end and to a sliding rod at the other. As the sliding rod is pulled, the spring begins to stretch, increasing the tension in the wire and causing the wire's vibration frequency to change accordingly. The tension is proportional to the spring's elongation. Therefore, changes in displacement can be detected by measuring the wire's tension, i.e., the change in its vibration frequency. Because the vibrating wire sensor directly outputs the wire's natural frequency signal, it exhibits strong anti-interference capabilities, minimal influence from electrical parameters, minimal zero drift, minimal temperature sensitivity, stable and reliable performance, vibration resistance, and a long lifespan.

[0034] The tunnel lining 1 is the lining at the tunnel vault arrangement position, which is the initial support surface of the tunnel during the construction period and the secondary lining surface of the tunnel during the operation period.

[0035] The connecting mechanism includes a fixed point expansion screw 2 vertically arranged on one side of the first vibrating wire displacement sensor 7. This point is a fixed point and can also be called a starting point or origin. The fixed point expansion screw 2 is welded by an expansion screw and a horizontal sensor line fixing tube, that is, a sleeve 3. The expansion screw can be made of a diameter of Φ8 and a length of 20 cm. The size of the sleeve 3 sensing line 4 is made. The sensing line 4 is a steel wire rope with a diameter of Φ1.5. The sleeve 3 can be made of a hollow 3mm steel pipe and 3 fixed wire screws are set. The connecting mechanism also includes a monitoring point lifting screw 10 vertically arranged on one side of the remaining vibrating wire displacement sensors 7. The monitoring point is a sensor installation outside the fixed point. The installation position is called the monitoring point. The lifting screw 10 is a connecting component of the monitoring point. It needs to be able to be adjusted up and down to accurately adjust the scale. The lifting screw 10 is similar to the fixed point expansion screw 2, but it is necessary to design and manufacture a scale 1001 and a lifting adjustment knob 11 on the rod. The scale should be 5 to 10 cm. The scale can record the lifting and lowering scale of the lifting knob and accurately calibrate it; the tops of the fixed point expansion screw 2 and the monitoring point lifting screw 10 are both connected to the tunnel lining 1 and the bottoms are both horizontally provided with a sleeve 3 matching the induction line 4, and a fixing screw 301 is provided on the sleeve 3, so that the induction line 4 passes through the corresponding sleeve 3 and is fixed by the fixing screw 301.

[0036] The sensing line 4 is equipped with a telescopic adjuster 6 for adjusting the tension of the vibrating wire displacement sensor 7. Connectors 5 are symmetrically provided at both ends of the telescopic adjuster 6 and the vibrating wire displacement sensor 7. The sensing line 4 is connected to the connectors 5. The connectors 5, telescopic adjuster 6, and vibrating wire displacement sensor 7 (including the cable) are the supporting components for sensor installation. The measuring range of the vibrating wire displacement sensor 7 should not be less than 20 cm.

[0037] like Figure 2 As shown, an inclination meter 21 can be added to the vibrating wire displacement sensor 7 to improve the measurement accuracy of the device.

[0038] An attached level adjustment bubble 9 is provided on the sensing line 4 to assist in adjusting the straightness. The attached level adjustment bubble 9 is a finished device that can be directly attached to any position on the sensing line 4 .

[0039] The chassis 17 is mounted on the inner wall of the tunnel. A wireless transmission LoRa module 13, connected to the multi-channel information collector 12, is located within the chassis 17. An alarm 15 is located on the top of the chassis 17. This alarm 15 is connected to the multi-channel information collector 12 via a relay 14. An antenna is also provided on the wireless transmission LoRa module 13. A chassis with a complete information collection unit can be connected to multiple vibrating wire displacement sensors 7 to collect data from multiple sensors. When the sensor detects a change in data exceeding a set threshold, the alarm 15 can sound an alarm and send an alarm message to the backend, providing a pre-warning function.

[0040] The battery 20 is connected to the external power supply 19 through a cable, and the external power supply 19 is connected to the battery 20 through a charge and discharge controller 18. The alarm 15 and the charge and discharge controller 18 are connected through a rectifier 16, and the rectifier 16 is connected to the wireless transmission LORA module 13 and the multi-channel information collector 12 through cables.

[0041] The specific installation method of the monitoring sensor unit of the device is as follows:

[0042] 1) Loft the expansion screw 2 at the fixed point and the lift screw 10 at the monitoring point onto the actual section according to the design drawing of the monitoring section, and record the absolute or relative coordinates of the two points;

[0043] 2) Install the expansion screw 2 at the fixed point and the lift screw 10 at the monitoring point, and connect the equipment according to the schematic diagram. Try to ensure that the equipment and the sensing line are connected horizontally between the two points. This step is a rough leveling to ensure that the adjustment space of the lift screw 10 is at the middle scale position;

[0044] 3) Using the telescopic adjuster 6, the vibrating wire displacement sensor 7 and the sensing wire 4 are tightened into a straight line, and the vibrating wire displacement sensor 7 is pre-stretched by 5 cm to 8 cm;

[0045] 4) Continuously read the initial value of the vibrating wire displacement sensor 7 for more than 10 times. If the changes in the 10 readings are close to the horizontal line, proceed to the next step. If the fluctuation is large, recheck the equipment status and the rationality of the installation;

[0046] 5) Use the lifting screw 10 and the attached level adjustment bubble 9 to adjust the horizontal measuring line to make it precisely level, and record the reading C1 of the vibrating wire displacement meter (unit: mm);

[0047] 6) Use the lifting screw 10 and the lifting adjustment knob 11 to lower the measuring point by 1 cm, 2 cm, and 3 cm, and record three readings D1, D2, and D3 respectively, in mm;

[0048] 7) Reverse adjustment is performed through the lifting and lowering adjustment device at the monitoring point to restore the measuring line to a horizontal level (fine leveling).

[0049] The specific requirements for the chassis 17 of the device are as follows:

[0050] 1) The acquisition and transmission system can be assembled according to the energy consumption and monitoring life of the sensor;

[0051] 2) The chassis 17 should be able to accommodate the corresponding internal functional modules and should also be of moderate size, which can be 40cm×40cm×20cm;

[0052] 3) The battery 20 can use a 12V-45A power supply to ensure that the acquisition device can be used normally when the power is off;

[0053] 4) The installation position of the chassis 17 should ensure easy maintenance and not hinder tunnel maintenance safety. The installation height should be 1.5m;

[0054] 5) The chassis 17 adopts the principle of one machine for two purposes, that is, one chassis collects monitoring point data of two sections.

[0055] like Figure 4-6 As shown, the device can be installed in the following three ways:

[0056] Method 1: Figure 4 As shown, after the fixed points are determined, the vibrating wire displacement sensors 7 are arranged in groups of two at the required spacing;

[0057] Method 2: Figure 5 As shown, after the fixing points are determined, the vibrating wire displacement sensors 7 are arranged in sequence in a single manner at the required spacing;

[0058] Method three, as follows Figure 6 As shown, after the fixing point is determined, the vibrating wire displacement sensors 7 close to the fixing point are arranged in groups of two, and the remaining vibrating wire displacement sensors 7 are arranged individually in sequence at the required intervals.

[0059] The third installation method is preferred among the above installation methods in actual installation situations, as the third installation method can fully utilize the first sensor and the second sensor for calibration.

[0060] The fixed point determined by the device can be set at one end alone, or fixed points can be set at both ends. In actual installation, the installation method in which fixed points are set at both ends is preferred.

[0061] The monitoring section distance of this device should not exceed 20m. If it exceeds 20m, additional monitoring sections can be added to solve the long-distance monitoring problem, as shown in Table 1 below:

[0062] Table 1 Spacing of sections for measuring perimeter displacement and vault subsidence

[0063]

[0064]

[0065] Note: In special areas such as rock formations with slip tendency, soft rock sections with large deformation or ultra-shallow buried soft soil formations, the measurement section can be appropriately increased.

[0066] During the construction period, monitoring and early warning values ​​should be selected based on the reserved deformation. The reserved deformation is proposed by the design unit and should be determined dynamically based on the surrounding rock grade of the actual tunnel construction. During the operation period, the value should be determined based on the margin of the reserved deformation during the construction period, the acceptable range of deformation space, and the allowable deformation of the concrete lining. The details are shown in Table 2 below:

[0067] Table 2 Reserved deformation (mm)

[0068]

[0069] Note: If the surrounding rock is broken, take the larger value; if the surrounding rock is intact, take the smaller value.

[0070] During the construction period, the construction status, warning level, and color coding can be determined according to Table 3 and Table 4. During the operation period, the warning level and color coding can be determined according to Table 5.

[0071] Table 3 Cumulative displacement warning levels during construction period

[0072] Management level Management displacement (mm) Construction status Color identification Ⅲ U<(U0 / 3) Normal construction is possible green Ⅱ (U0 / 3)≤U≤(2U0 / 3) Support should be strengthened orange color Ⅰ U>(2U0 / 3) Special measures should be taken red

[0073] Table 4 Change displacement warning level

[0074]

[0075]

[0076] Table 5 Cumulative displacement warning levels during operation period

[0077] Warning level Warning value distribution Response measures Color identification Ⅲ U<Un / 3 Normal care green Ⅱ Un / 3≤U≤2Un / 3 Encrypted monitoring frequency, special tracking orange color Ⅰ U>2Un / 3 Traffic control, special diagnosis and treatment red

[0078] like Figure 7 、 8 As shown, the data processing method of the device is:

[0079] (1) Absolute horizontal distance S between two measuring points i Confirm (see attached Figure 8 )

[0080] 1) Point O in the figure is a fixed point, located on a stable lining. Points A and B are the arch sinking monitoring points where settlement deformation may occur. The monitoring points can be extended as needed. Absolute horizontal distance S i Represents S1 or S2 in the figure, and the absolute horizontal distance between monitoring points not shown.

[0081] 2) When calibrating the device, move one of the measuring points down 1cm, 2cm, and 3cm, and record three readings D1, D2, and D3 respectively. Assuming the horizontal distance is x, the absolute horizontal distance S between any two points can be deduced. i , using S1 between OA points, the derivation is as follows:

[0082] (x1+D1) 2 =x1 2 +1 2 (1)

[0083] (x1+D2) 2 =x1 2 +2 2 (2)

[0084] (x+D3) 2 =x3 2 +3 2 (3)

[0085]

[0086] 3) The same as item 2) can be used to derive S2 and the absolute horizontal distance between any two consecutive vault settlement measurement points.

[0087] (2) Calculation of the settlement of a fixed point and a moving point, such as the calculation of the relative settlement h between the fixed point O and the monitoring point A, that is, the absolute settlement h of point A A Calculate (h = h A ), given the sensor reading s at any time, we have:

[0088]

[0089] (3) Calculation of settlement between two moving points, such as settlement between points A and B, given that the absolute horizontal distance between A and B is S2 and the absolute settlement of point A is h A Based on h B :

[0090] (S2+D AB ) 2 -S2 2 =(h A -h B ) 2 (7)

[0091]

[0092] From formulas (7) and (8), we can know that h A There exists a value greater than or equal to h B From this we can see that the change of relative point exists as shown in the following Figure 7 Therefore, it is necessary to weld the corresponding inclinometer 21 (see attached figure) on the vibrating wire displacement sensor 7. Figure 2 ), obtain the deflection direction of points A and B, and thus determine the positive and negative signs in formula (8). If the angle is measured as shown in the attached figure Figure 7When 2-2 and 2-3 change, they take negative signs, and when 2-5 changes, they take positive signs. If the angle does not deflect or the horizontal distance S2 remains unchanged, then h A =h B The relative subsidence values ​​of the two monitoring points are thus obtained.

[0093] In the tunnel direction, the relative subsidence deformation law between the arch subsidence monitoring points of the two monitoring sections always changes from a straight line to a right triangle. Therefore, it is only necessary to measure the change in the slope distance of the deformation triangle between the two points to convert the relative subsidence value of the two points. Figure 7 The five deformation model calculation methods shown in 2-1 to 2-5 can accurately sense the amount of arch sinking deformation in real time, obtain the corresponding deformation relationship curve, and realize real-time data collection and early warning.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model and are not limiting. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the utility model.

Claims

1. An automatic monitoring and early warning device for tunnel vault subsidence, characterized by: It comprises a monitoring sensor unit, an information acquisition and transmission unit and a connection mechanism, wherein the monitoring sensor unit comprises one or more vibrating wire displacement sensors (7), the information acquisition and transmission unit comprises a multi-channel information acquisition instrument (12), the multi-channel information acquisition instrument (12) is connected to the circuit of the vibrating wire displacement sensor (7) via a cable (8), the connection mechanism comprises an induction line (4) and two or more lining connecting rods, the lining connecting rods are connected to the top of the tunnel lining (1) along the length direction of the tunnel vault, and the vibrating wire displacement sensor (7) is connected between the two lining connecting rods via the induction line (4).

2. The automatic monitoring and early warning device for tunnel vault subsidence according to claim 1 is characterized in that: The connecting mechanism further comprises a telescopic adjuster (6) for adjusting the pre-stretch length of the vibrating wire displacement sensor, and the telescopic adjuster (6) is connected in series to the sensing line (4).

3. The automatic monitoring and early warning device for tunnel vault subsidence according to claim 2 is characterized in that: An attached level adjustment bubble (9) for assisting in adjusting the straightness is provided on the sensing line (4).

4. The automatic monitoring and early warning device for tunnel vault subsidence according to claim 3 is characterized by: The lining connecting rod comprises a fixed-point expansion screw (2) with a fixed length and a liftable screw (10) with an adjustable length. The fixed-point expansion screw (2) is installed on the lining at the end of the tunnel, and the liftable screw (10) is installed on other set tunnel linings.

5. The automatic monitoring and early warning device for tunnel vault subsidence according to claim 4 is characterized in that: The liftable screw (10) adopts a manual screw lifting mechanism. A sleeve (3) for connecting the sensing line (4) is provided at the lower end of the fixed point expansion screw (2) and the liftable screw (10). A fixed line screw (301) is provided on the sleeve (3). The sensing line (4) passes through the corresponding sleeve (3) and is fixed by the fixed line screw (301).

6. The automatic monitoring and early warning device for tunnel vault subsidence according to claim 1 is characterized in that: The multi-channel information collector (12) is arranged in a chassis (17), a battery (20) connected to the multi-channel information collector (12) is arranged in the chassis (17), the chassis (17) is arranged on the inner wall of the tunnel, a wireless transmission LORA module (13) connected to the circuit of the multi-channel information collector (12) is also arranged in the chassis (17), and an alarm (15) is arranged on the top of the chassis (17), and the alarm (15) is connected to the circuit of the multi-channel information collector (12) through a relay (14).

7. The automatic monitoring and early warning device for tunnel vault subsidence according to claim 6 is characterized in that: The battery (20) is connected to an external power source (19) via a cable, the external power source (19) is connected to the battery (20) via a charge and discharge controller (18), the alarm (15) and the charge and discharge controller (18) are connected via a rectifier (16), and the rectifier (16) is connected to a wireless transmission LORA module (13) and a multi-channel information collector (12) via cables.

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