A cross-section settlement monitoring system and monitoring method based on fiber grating sensor

Abstract

The invention discloses a cross-section settlement monitoring system and a monitoring method based on a fiber grating sensor. The cross-section settlement monitoring system comprises a rigid support, a plurality of displacement sensors, a plurality of rigid pull lines, a plurality of monitoring anchor points, two inclinometer rigid beams, a plurality of inclination sensors, two inclinometer legs, a plurality of pulleys with hooks, an optical cable, a fiber grating demodulator, a power supply unit and a monitoring and early warning platform; two simply supported legs of the rigid support are installed on both sides of a settlement monitoring area, a settlement rigid beam is installed on the simply supported legs, a plurality of displacement sensors are evenly arranged on the settlement rigid beam, and the plurality of displacement sensors are connected to the monitoring anchor points through rigid pull lines; the simply supported legs are connected to the inclinometer rigid beam through a rotating shaft, and an inclinometer rigid beam and a displacement sensor are installed on the inclinometer rigid beam. The invention monitors data through a plurality of displacement sensors and a plurality of inclinometer sensors, and can calculate settlement data within the range of the settlement rigid beam.

Description

Technical Field

[0001] The invention belongs to the technical field of fiber grating sensors, and in particular relates to a section settlement monitoring system and a monitoring method based on fiber grating sensors. Background Art

[0002] There are uneven settlement wind directions in the key sections with tunnels passing through, roads with culverts under construction, weak sections of cast-in-place box beam supports, etc., and settlement disasters are highly concealed and sudden. Therefore, settlement monitoring of weak construction sections has gradually become a regulatory requirement. At present, the total station is mainly used to intermittently monitor the set points, but this monitoring method has problems such as high cost, complex operation, poor real-time performance, and poor durability. The monitoring method using vibrating string sensors is used for monitoring. Research on vibrating string sensors shows that its electrical monitoring principle limits its service life and cannot be monitored in real time. Real-time online monitoring of cross-section settlement is to timely discover the deformation of the weak sections of the monitored buildings and structures during the construction process and operation period, evaluate their safety status, and prevent potential safety hazards. Through real-time online monitoring of the structural deformation of the weak sections of the monitored buildings and structures, it can provide a scientific basis for the design, construction and maintenance of buildings and structures, and improve the construction quality.

[0003] Fiber Bragg grating sensor is a wavelength modulated fiber optic sensor. The basic working principle is that light enters the grating area through the optical fiber, and through the change of external quantity, it causes multiple parameters of light in the grating area to change, such as wavelength, intensity, amplitude, frequency, etc., so as to measure the external quantity and realize data transmission. Fiber Bragg grating sensor has the characteristics of strong anti-interference ability, no electromagnetic interference, high measurement accuracy, easy distributed networking, good environmental adaptability, etc. Fiber Bragg grating sensor is a safety product, widely used in remote, online, real-time, intelligent monitoring of mines, bridges, tunnels, deep foundation pits, high slopes, prefabricated buildings, etc.

[0004] At present, domestic and foreign manufacturers engaged in fiber grating sensing technology generally use epoxy resin, fiber grating and sensor matrix to encapsulate the substrate. The epoxy resin glue is only combined with the sensor matrix through physical bonding. The bonding method is not strong and the epoxy resin glue is easily damaged and falls off in high temperature, high humidity, strong ultraviolet rays and corrosive environments, which needs further improvement. Summary of the invention

[0005] The present invention provides a cross-sectional settlement monitoring system and a monitoring method based on a fiber grating sensor to meet the needs of real-time, online, efficient and high-precision monitoring of weak sections of buildings and structures. At the same time, multiple groups of the monitoring devices can be used in combination to construct a three-dimensional settlement model, and each group can be repeatedly used in a cycle, which is economical and easy to operate. It can solve the problems of high cost, complex installation and operation, poor real-time performance and poor durability of traditional monitoring methods.

[0006] To solve the above problems, the technical solution provided by the present invention is as follows:

[0007] The embodiment of the present invention provides a cross-section settlement monitoring system based on a fiber grating sensor, comprising a rigid support (1), a plurality of displacement sensors (2), a plurality of rigid pull lines (3), a plurality of monitoring anchor points (4), two inclination measuring rigid beams (5), a plurality of inclination sensors (6), two inclination measuring legs (7), a plurality of pulleys with hooks (8), an optical cable (9), a fiber grating demodulator (10), a power supply unit (11), a monitoring and early warning platform (12), a remote monitoring center (13) and a mobile terminal (14);

[0008] The rigid support (1) is arranged on the settlement risk section of the monitored structure, two inclinometer rigid beams (5) are connected to both sides of the rigid support (1), two inclinometer legs (7) are connected to the ends of the two inclinometer rigid beams (5), a plurality of monitoring anchor points (4) are fixed on the ground below the rigid support (1), a plurality of displacement sensors (2) arranged at intervals on the settlement rigid beam (102) of the rigid support (1) are connected to the monitoring anchor points (4) through the rigid pull wire (3); at least one inclination sensor (6) is arranged on the bottom of the inclinometer rigid beam (5), a notch (502) opened at the end of the inclinometer rigid beam (5) is provided with the hook pulley (8), and the displacement sensors (2) arranged on the inclinometer rigid beam (5) are fixed to the hook pulley (8) through the rigid pull wire (3);

[0009] All displacement sensors (2) and the tilt sensors (6) are used to obtain settlement data within the range of the settlement rigid beam (102); all displacement sensors (2) and the tilt sensors (6) are connected to the fiber optic Bragg grating demodulator (10) via the optical cable (9); the power supply unit (11) provides power to the fiber optic Bragg grating demodulator (10); the fiber optic Bragg grating demodulator (10) transmits the collected data to the monitoring and early warning platform (12) via wireless transmission; the monitoring and early warning platform (12) collects and processes the data to extract information on the amount of settlement, draws a settlement curve, analyzes the settlement trend, and monitors the data according to preset data quality standards and rules; once the data is found to be abnormal or exceeds a preset range, an alarm is immediately issued, thereby providing a scientific basis for the safe operation and maintenance of the monitored structure; the data can also be sent to the remote monitoring center (13) and the mobile terminal (14) to issue accident warnings in a timely manner.

[0010] According to an optional embodiment of the present invention, the rigid support (1) is a portal structure, comprising a settlement rigid beam (102), and two simply supported legs (101) located at both ends of the settlement rigid beam (102), and a long simply supported base (103) is provided at the bottom of the two simply supported legs (101), and a first rotating shaft (104) is provided at the center position where the two simply supported legs (101) are connected to the settlement rigid beam (102), and the first rotating shaft (104) passes through the first axial hole (501) provided in the inclinometer rigid beam (5), and the rigid support (1) and the inclinometer rigid beam (5) can flexibly rotate around the first rotating shaft (104).

[0011] According to an optional embodiment of the present invention, a second rotating shaft (702) is provided on the upper part of the inclinometer leg column (701) of the inclinometer leg (7), and the second rotating shaft (702) can slide flexibly in the slot (502); a plate-shaped bottom plate (703) is provided at the bottom of the inclinometer leg column (701), and the hook pulley (8) is fixed on the second rotating shaft (702).

[0012] According to an optional embodiment of the present invention, the simply supported leg (101), the settlement rigid beam (102) and the inclinometer leg (7) are all square rod-shaped or plate-shaped structures.

[0013] According to an optional embodiment of the present invention, the monitoring anchor point (4) includes a mounting base (401), and a fixing connection device (402) is provided on the mounting base (401); the mounting base (401) of the monitoring anchor point (4) and the monitored component are firmly fixed to the ground by means of expansion screws, pre-embedding, and manufacturing of a foundation.

[0014] According to an optional embodiment of the present invention, the hook pulley (8) includes a hook (8-01), a pulley shaft (8-02), a bearing (8-03) and a bearing sleeve (8-04), the hook (8-01) is fixed on the outer diameter of the bearing sleeve (8-04), the bearing sleeve (8-04) is embedded in the bearing (8-03), and the bearing (8-03) and the pulley shaft (8-02) are in rolling connection.

[0015] The embodiment of the present invention further provides a cross-section settlement monitoring method based on a fiber grating sensor, which is implemented by a cross-section settlement monitoring system based on a fiber grating sensor as in the above embodiment, wherein the cross-section settlement monitoring method comprises the following steps:

[0016] Step S1, in a scene where cross-section settlement monitoring is required for a key section with a tunnel passing through, a road with a culvert under construction, or a cast-in-place box girder support, the cross-section settlement monitoring system is set at a cross-section with a settlement risk, with two simply supported legs (101) on both sides of the settlement monitoring area, and a simply supported base (103) is simply supported by the ground; at a measurement starting position, the center line of the simply supported legs (101) is perpendicular to the ground, and the two inclinometer legs (7) are arranged at a horizontal position where no settlement is set, and are distributed outside the two simply supported legs (101), the center line of the inclinometer legs (7) is perpendicular to the ground, and the center line of the settlement rigid beam (102) is perpendicular to the ground;

[0017] Step S2, setting the center point of the left first rotating shaft (104) as point A, the center point of the right first rotating shaft (104) as point B, the projection of A onto the plane below the simply supported base (103) as point D, the projection of B onto the plane below the simply supported base (103) as point C, the center point of the left second rotating shaft (702) of the inclinometer leg (7) as point E, the center point of the right second rotating shaft (702) of the inclinometer leg (7) as point F, the projection of E onto the plane below the bottom plate (703) as point H, and the projection of F onto the plane below the bottom plate (703) as point G; the center point of the left first displacement sensor as W1; the center point of the left second displacement sensor as W2... the projection of the center point W1 of the left first displacement sensor onto the plane below the monitoring anchor point as W01; the projection of the center point of the left second displacement sensor onto the plane below the monitoring anchor point as W02;

[0018] Step S3, the initial measurement position AD=BC=EH=FG=h1; AB=CD=l1, AE=BF=l 2, The uniformly distributed gap between displacement meters on the settlement rigid beam (102) is a, W1W 01 =W2W 02 ... = c;

[0019] Step S4, when settlement occurs between AD and BC, the horizontal line inclination angle of the left inclination sensor (6) measured on the left inclination measuring rigid beam (5) is θ 左 , the displacement sensor (2) on the left side measures the displacement λ 左 The measured inclination angle between the left inclination sensor (6) of the right inclinometer rigid beam (5) and the horizontal line is θ 右 , the displacement sensor (2) on the left side measures the displacement λ 右 ; The data measured by the displacement sensor (2) on the settlement rigid beam (102) are respectively: c1, c2... from left to right;

[0020] It can be calculated that:

[0021] AE=l 2+ λ 左 ,BF=l 2+ λ 右 ;

[0022] Point A sinking = Point D sinking = (l 2+ λ 左 )×Sinθ 左 ;

[0023] Point B sinking = Point C sinking = (l 2+ λ 右 )×Sinθ 右 ;

[0024] The calculations show that:

[0025] The angle between AB and the horizontal is θ 中 =arcsin[(|λ 左 -λ 右 |) / l1];

[0026] sinθ 中 =(|λ 左 -λ 右 |) / l1;

[0027] The sinking of point W1 relative to point A = c × sinθ 中 =c×[(|λ 左 -λ 右 |) / l1];

[0028] The sinking of point W2 relative to point A = 2c × sinθ 中 =2c×[(|λ 左 -λ 右 |) / l1];

[0029] …

[0030] Absolute sinking of point W1 = sinking of point A + sinking of point W1 relative to point A = (l 2+ λ 左 )×Sinθ 左 +c×[(|λ 左 -λ 右 |) / l1];

[0031] Absolute sinking of point W2 = sinking of point A + sinking of point W2 relative to point A = (l2+λ 左 )×Sinθ 左 +2c×[(|λ 左 -λ 右 |) / l1];

[0032] …

[0033] According to the sedimentation rule, W1 and W 01 , W2 and W 02 ...It is not necessary to consider that its projection position along the AD and BC directions will produce relative sliding;

[0034] W 01 Absolute sinking of point = Absolute sinking of point W1 + (h1 + c1) × cosθ 中 =(l2+λ 左 )×Sinθ 左 +c×sinθ 中 + = (l2 + λ 左 )×Sinθ 左 +c×sin{arcsin[(|λ 左 -λ 右 | / l1)]}+c1;

[0035] W 02 Absolute sinking of point = Absolute sinking of point W2 + (h1 + c2) × cosθ 中 =(l2+λ 左 )×Sinθ 左 +2c×sinθ 中 =(l2+λ 左 )×Sinθ 左 +2c×sin{arcsin[(|λ 左 -λ 右 | / l1)]}+c2;

[0036] Thus, the settlement data of each point D, W01, W02, W03 ... C can be obtained, and a settlement curve can be drawn based on the data; all displacement sensors (2) and inclination sensors (6) are connected to a fiber optic Bragg grating demodulator (10) through an optical cable (9), and a power supply unit (11) provides power for the fiber optic Bragg grating demodulator (10); the fiber optic Bragg grating demodulator (10) transmits the collected data to a monitoring and early warning platform (12) via wireless transmission, and the monitoring and early warning platform (12) collects and processes the data to extract information on the settlement amount, draws a settlement curve, analyzes the settlement trend, and monitors the data according to preset data quality standards and rules. Once the data is found to be abnormal or exceeds the preset range, an alarm will be immediately issued, providing a scientific basis for the safe operation and maintenance of the monitored structure; the data can also be sent to a remote monitoring center (13) and a mobile terminal (14) to issue accident warnings in a timely manner.

[0037] Compared with the prior art, the embodiment of the present invention provides a section settlement monitoring system and monitoring method based on fiber grating sensors, which has the following beneficial effects:

[0038] (1) Real-time online monitoring of cross-section settlement is to timely discover the deformation of weak sections of the monitored buildings and structures during the construction process and operation period, evaluate their safety status, and prevent potential safety hazards. Through real-time online monitoring of the structural deformation of weak sections of monitored buildings and structures, a scientific basis can be provided for the design, construction and maintenance of buildings and structures, thereby improving construction quality.

[0039] (2) The cross-section settlement monitoring system of the present invention is simple and efficient to deploy, and is suitable for settlement monitoring of key sections with tunnels passing through, roads with culverts under construction, weak sections of structures such as cast-in-place box beam supports, etc., and is not affected by construction. It uses optical fiber Bragg grating sensors for monitoring, which consumes little energy. Compared with traditional measurement methods, the system of the present invention has a simple structure, low cost, is reusable, and is easy to promote and apply.

[0040] (3) Chinese patent CN112230327A discloses "an all-glass packaging device and packaging method for fiber gratings". The present invention is based on the patent technology and innovatively develops a new fiber grating sensor substrate. While having the characteristics of fiber grating sensors such as strong anti-interference ability, no electromagnetic interference, high measurement accuracy, easy distributed networking, and good environmental adaptability, it solves the current problems of poor durability and stability of fiber grating sensors.

[0041] (4) The present invention is based on a new fiber grating sensor substrate. The various new fiber grating sensors developed by the present invention utilize the fiber grating sensing principle to achieve high-precision measurement of settlement, displacement, and inclination. The monitoring and early warning platform can monitor displacement, inclination, temperature and other parameters separately, and the monitoring data can be independently monitored without interfering with each other. It can establish a dynamic model with the initial surveying and mapping data to display its changes in real time. Setting the alarm threshold can achieve segmented early warning, and the monitoring data can be wirelessly transmitted in real time to achieve remote and local synchronous early warning, which can effectively avoid the occurrence of accidents. The monitoring and early warning platform can realize centralized management and analysis of data, reducing the complexity and errors of manual operations.

[0042] (5) The sensors in the monitoring system of the present invention are modularly installed, which is convenient and efficient to install. The power supply unit adopts a combination of UPS and solar panels, etc., and there is no need to lay separate lines, which meets the needs of on-site engineering construction. It is easy to repair and replace, and can be reused. The optical fiber layout of the monitoring device is scientific and reasonable, which can effectively reduce losses;

[0043] Therefore, the present invention proposes a cross-sectional settlement monitoring system and monitoring method based on fiber grating sensors, which are suitable for the real-time, online, efficient and high-precision monitoring of weak sections of structures such as key sections with tunnels passing through, roads with culverts under construction, and cast-in-place box girder supports. At the same time, multiple groups of the monitoring devices can be used in combination to construct a three-dimensional settlement model, and each group can be repeatedly used in a cycle, which is economical and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 A schematic diagram of a cross-section settlement monitoring system based on a fiber grating sensor provided in an embodiment of the present application.

[0046] Figure 2 A front view of the partial functional structure of a cross-section settlement monitoring system based on a fiber grating sensor provided in an embodiment of the present application.

[0047] Figure 3 A three-dimensional diagram of the partial functional structure of a cross-section settlement monitoring system based on a fiber grating sensor provided in an embodiment of the present application.

[0048] Figure 4 A schematic diagram of the monitoring anchor point structure in a cross-section settlement monitoring system based on a fiber grating sensor provided in an embodiment of the present application.

[0049] Figure 5 A schematic diagram of a hook pulley structure in a cross-section settlement monitoring system based on a fiber grating sensor provided in an embodiment of the present application.

[0050] Figure 6 A schematic diagram of the installation of a displacement sensor on a settlement rigid beam of a cross-section settlement monitoring system based on a fiber grating sensor provided in an embodiment of the present application.

[0051] Figure 7 A schematic diagram of the installation of a displacement sensor on an inclinometer rigid beam in a cross-section settlement monitoring system based on a fiber grating sensor provided in an embodiment of the present application.

[0052] Figure 8 A simplified point-and-line diagram of the initial positions of the weak section section settlement monitoring positions ABCDEFGH provided in an embodiment of the present application.

[0053] Fig. 9A simplified point-and-line diagram of the initial positions of the weak section section settlement monitoring positions ABCDEFGH provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0055] like Figure 1 to Figure 7 As shown, an embodiment of the present invention provides a cross-section settlement monitoring system based on a fiber grating sensor, including a rigid bracket 1, multiple displacement sensors 2, multiple rigid pull lines 3, multiple monitoring anchor points 4, two inclinometer rigid beams 5, multiple inclination sensors 6, two inclinometer legs 7, multiple pulleys with hooks 8, an optical cable 9, a fiber grating demodulator 10, a power supply unit 11, a monitoring and early warning platform 12, a remote monitoring center 13 and a mobile terminal 14.

[0056] like Figure 1 , Figure 2 , Figure 3 , Figure 6 and Figure 7 As shown, the rigid support 1 is arranged on the settlement risk section (settlement weak section section) of the monitored structure, two inclinometer rigid beams 5 are connected on both sides of the rigid support 1, two inclinometer legs 7 are connected to the ends of the two inclinometer rigid beams 5, and a plurality of monitoring anchor points 4 are fixed on the ground below the rigid support 1. A plurality of displacement sensors 2 arranged at intervals on the settlement rigid beam 102 of the rigid support 1 are all connected to the monitoring anchor points 4 through rigid pull wires 3; at least one inclination sensor 6 is arranged on the bottom of the inclinometer rigid beam 5, and a hook pulley 8 is arranged at the notch 502 opened at the end of the inclinometer rigid beam 5, and the displacement sensors 2 arranged on the inclinometer rigid beam 5 are all fixed on the hook pulley 8 through rigid pull wires 3.

[0057] All displacement sensors 2 and inclination sensors 6 are used to obtain settlement data within the range of the settlement rigid beam 102; all displacement sensors 2 and inclination sensors 6 are connected to the fiber grating demodulator 10 through the optical cable 9, and the power supply unit 11 provides power for the fiber grating demodulator 10. The fiber grating demodulator 10 transmits the collected data to the monitoring and early warning platform 12 via wireless transmission. The monitoring and early warning platform 12 collects and processes the data to extract the information of the settlement amount, draws the settlement curve, analyzes the settlement trend, and monitors the data according to the preset data quality standards and rules. Once the data is found to be abnormal or exceeds the preset range, an alarm will be issued immediately, providing a scientific basis for the safe operation and maintenance of the monitored structure. The data can also be sent to the remote monitoring center 13 and the mobile terminal 14 to issue accident warnings in time.

[0058] The rigid support 1 is a gantry structure, including a settlement rigid beam 102, and two simply supported legs 101 located at both ends of the settlement rigid beam 102. The settlement rigid beam 102 and the two simply supported legs 101 are rigidly connected. The center line of the simply supported base 103 is perpendicular to the cross section. A long strip of simply supported base 103 is provided at the bottom of the two simply supported legs 101. Two first rotating shafts 104 are provided at the center position where the two simply supported legs 101 are connected to the settlement rigid beam 102. The first rotating shaft 104 passes through the first axial hole 501 provided by the inclinometer rigid beam 5. The rigid support 1 and the inclinometer rigid beam 5 can rotate flexibly around the first rotating shaft 104. A notch 502 is provided at the other end of the inclinometer rigid beam. A second rotating shaft 702 is provided on the upper part of the inclinometer leg column 701 of the inclinometer leg 7, and the second rotating shaft 702 can slide flexibly in the slot 502; a plate-shaped bottom plate 703 is provided at the bottom of the inclinometer leg column 701, and a hook pulley 8 is fixed on the second rotating shaft 702.

[0059] The simply supported legs 101, the settlement rigid beam 102 and the inclinometer legs 7 are all square rod-shaped or plate-shaped structures, and their center lines are coplanar. The bottom surface of the simply supported base 103 is coplanar with the bottom surface of the bottom plate 703. Figure 4 As shown, the monitoring anchor point 4 includes a mounting base 401, on which a fixing connection device 402 is provided; the mounting base 401 of the monitoring anchor point 4 and the monitored component are firmly fixed to the ground by means of expansion screws, pre-embedding, and making a cap. The inclinometer base plate 703 of the inclinometer leg 7 and the mounting base plate 401 of the monitoring anchor point 4 are both firmly fixed to the ground.

[0060] like Figure 5 As shown, the hook pulley 8 includes a hook 8-01, a pulley shaft 8-02, a bearing 8-03 and a bearing sleeve 8-04, the hook 8-01 is fixed on the outer diameter of the bearing sleeve 8-04, the bearing sleeve 8-04 is embedded in the bearing 8-03, and the bearing 8-03 and the pulley shaft 8-02 are in rolling connection.

[0061] Preferably, two displacement sensors 2 are arranged on the inclinometer rigid beam 5, two hook pulleys 8 are fixed on two second rotating shafts 702 respectively, and the center line of the hook 8-01 is collinear with the center line of the second rotating shaft 702, the center line of the pulley shaft 8-02 is collinear with the center line, and the bearing 8-03 slides flexibly around the pulley shaft 8-02; multiple displacement sensors 2 are connected to multiple rigid pull wires 3, and the rigid pull wire axis is collinear with the monitoring direction of the displacement sensor 2. Multiple rigid pull wires 3 are firmly connected to the fixed connection devices 402 of multiple monitoring anchor points 4 and the hook 8-01 of the hook pulley 8, and the displacement sensor 2 monitors data with the axial movement of the rigid pull wire 3. The inclination sensor 6 is installed on the inclinometer rigid beam 5, and the inclination sensor 6 monitors the rotation angle 0 point plane perpendicular to the axis of the first rotating shaft 104.

[0062] In another embodiment, the connection between the displacement sensor and the rigid pull wire, the rigid pull wire and the monitoring anchor point, and the rigid pull wire and the hook pulley can be replaced with a bolt locking structure. In another embodiment, the shaft hole can be replaced, and can be a shaft hole, a hole shaft, a through shaft perforation and other structures. In another embodiment, the inclinometer base plate 703 of the inclinometer leg 7 and the mounting base plate 401 of the monitoring anchor point 4 can be firmly fixed to the ground by expansion screws, pre-embedding, making a base and the like. In another embodiment, all sensors can be connected in series to the fiber optic Bragg grating demodulator 10, or they can be connected to the fiber optic Bragg grating demodulator 10 separately through an optical cable 9. In another embodiment, the rigid bracket can be processed as a whole by welding or the like, or it can be fixed and connected as a whole by bolts.

[0063] The embodiment of the present invention further provides a cross-section settlement monitoring method based on a fiber grating sensor, which is implemented by a cross-section settlement monitoring system based on a fiber grating sensor as in the above embodiment, wherein the cross-section settlement monitoring method comprises the following steps:

[0064] Step S1, in scenes where cross-section settlement monitoring is required, such as key sections with tunnels passing through, roads with culverts under construction, cast-in-place box girder supports, etc., a cross-section settlement monitoring system is set up at sections with settlement risks, with two simply supported legs 101 on both sides of the settlement monitoring area, and a simply supported base 103 is simply supported by the ground; at the measurement starting position, the center line of the simply supported legs 101 is perpendicular to the ground, and the two inclinometer legs 7 are arranged at a horizontal position where no settlement is set, and are distributed on the outside of the two simply supported legs 101, with the center line of the inclinometer legs 7 perpendicular to the ground, and the center line of the settlement rigid beam 102 perpendicular to the ground.

[0065] Step S2, set the center point of the left first rotating shaft 104 to point A, the center point of the right first rotating shaft 104 to point B, the projection of A to the plane point below the simply supported base 103 to point D, the projection of B to the plane point below the simply supported base 103 to point C, the center point of the left second rotating shaft 702 of the inclinometer leg 7 to point E, the center point of the right second rotating shaft 702 of the inclinometer leg 7 to point F, the projection of E to the plane point below the bottom plate 703 to point H, and the projection of F to the plane point below the bottom plate 703 to point G; the center point of the left first displacement sensor is W1; the center point of the left second displacement sensor is W2... The projection of the center point W1 of the left first displacement sensor to the plane below the monitoring anchor point is W01; the projection of the center point of the left second displacement sensor to the plane below the monitoring anchor point is W02, reference Figure 8 ;

[0066] Step S3, the initial measurement position AD=BC=EH=FG=h1; AB=CD=l1, AE=BF=l 2, The uniform gap between displacement meters on the settlement rigid beam 102 is a, W1W 01 =W2W 02 ... = c;

[0067] Step S4: When settlement occurs between AD and BC, the horizontal line inclination angle of the left inclination sensor 6 measured on the left inclination measuring rigid beam 5 is θ 左 , the displacement sensor 2 on the left side measures the displacement λ 左 The inclination angle between the left inclination sensor 6 and the horizontal line is θ 右 , the displacement sensor 2 on the left side measures the displacement λ 右 ; The displacement sensor 2 on the settlement rigid beam 102 measures the data from left to right: c1, c2..., reference Fig. 9 ;

[0068] It can be calculated that:

[0069] AE=l 2+ λ 左 ,BF=l 2+ λ 右 ;

[0070] Point A sinking = Point D sinking = (l 2+ λ 左 )×Sinθ 左 ;

[0071] Point B sinking = Point C sinking = (l 2+ λ 右 )×Sinθ 右 ;

[0072] The calculations show that:

[0073] The angle between AB and the horizontal is θ 中=arcsin[(|λ 左 -λ 右 |) / l1];

[0074] sinθ 中 =(|λ 左 -λ 右 |) / l1;

[0075] The sinking of point W1 relative to point A = c × sinθ 中 =c×[(|λ 左 -λ 右 |) / l1];

[0076] The sinking of point W2 relative to point A = 2c × sinθ 中 =2c×[(|λ 左 -λ 右 |) / l1];

[0077] …

[0078] Absolute sinking of point W1 = sinking of point A + sinking of point W1 relative to point A = (l 2+ λ 左 )×Sinθ 左 +c×[(|λ 左 -λ 右 |) / l1];

[0079] Absolute sinking of point W2 = sinking of point A + sinking of point W2 relative to point A = (l 2+ λ 左 )×Sinθ 左 +2c×[(|λ 左 -λ 右 |) / l1];

[0080] …

[0081] According to the sedimentation rule, W1 and W 01 , W2 and W 02 ...It is not necessary to consider that its projection position along the AD and BC directions will produce relative sliding;

[0082] W 01 Absolute sinking of point = Absolute sinking of point W1 + (h1 + c1) × cosθ 中 =(l 2+ λ 左 )×Sinθ 左 +c×sinθ 中 + = (l2 + λ 左 )×Sinθ 左 +c×sin{arcsin[(|λ 左 -λ 右 | / l1)]}+c1;

[0083] W 02 Absolute sinking of point = Absolute sinking of point W2 + (h1 + c2) × cosθ 中 =(l2+λ 左 )×Sinθ 左 +2c×sinθ 中 =(l2+λ 左 )×Sinθ 左 +2c×sin{arcsin[(|λ 左 -λ 右 | / l1)]}+c2;

[0084] From this, the settlement data of points D, W01, W02, W03…C can be obtained, and the settlement curve can be drawn based on the data;

[0085] All displacement sensors 2 and inclination sensors 6 are connected to a fiber grating demodulator 10 via an optical cable 9, and a power supply unit 11 provides power for the fiber grating demodulator 10; the fiber grating demodulator 10 transmits the collected data to a monitoring and early warning platform 12 via wireless transmission, and the monitoring and early warning platform 12 collects and processes the data to extract the information on the amount of settlement, draws a settlement curve, analyzes the settlement trend, and monitors the data according to preset data quality standards and rules. Once the data is found to be abnormal or exceeds the preset range, an alarm will be issued immediately, providing a scientific basis for the safe operation and maintenance of the monitored structure; the data can also be sent to a remote monitoring center 13 and a mobile terminal 14 to provide timely accident warnings.

[0086] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to them. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered within the protection scope of the present invention. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be based on the scope defined by the claims.

Claims

1. A cross-section settlement monitoring system based on fiber grating sensors, characterized in that: It comprises a rigid support (1), a plurality of displacement sensors (2), a plurality of rigid pull lines (3), a plurality of monitoring anchor points (4), two inclinometer rigid beams (5), a plurality of inclination sensors (6), two inclinometer legs (7), a plurality of pulleys with hooks (8), an optical cable (9), a fiber grating demodulator (10), a power supply unit (11), a monitoring and early warning platform (12), a remote monitoring center (13) and a mobile terminal (14); The rigid support (1) is arranged on the settlement risk section of the monitored structure, two inclinometer rigid beams (5) are connected to both sides of the rigid support (1), two inclinometer legs (7) are connected to the ends of the two inclinometer rigid beams (5), and the rigid support (1) and the inclinometer rigid beams (5) can be flexibly rotated around a first rotation axis (104); a plurality of monitoring anchor points (4) are fixed on the ground below the rigid support (1), and a plurality of displacement sensors (2) arranged at intervals on the settlement rigid beam (102) of the rigid support (1) are connected to the monitoring anchor points (102) via the rigid pull wire (3). The inclination measuring rigid beam (5) is connected to an anchor point (4); at least one inclination sensor (6) is arranged on the bottom of the inclination measuring rigid beam (5); the notch (502) opened at the end of the inclination measuring rigid beam (5) is provided with the hook pulley (8); the displacement sensors (2) arranged on the inclination measuring rigid beam (5) are all fixed to the hook pulley (8) through a rigid pull wire (3); a plurality of rigid pull wires (3) are respectively firmly connected to the fixed connection devices (402) of a plurality of monitoring anchor points (4) and the hook (8-01) of the hook pulley (8), and the displacement sensor (2) performs data monitoring along with the axial movement of the rigid pull wire (3); All displacement sensors (2) and the tilt sensors (6) are used to obtain settlement data within the range of the settlement rigid beam (102); all displacement sensors (2) and the tilt sensors (6) are connected to the fiber optic Bragg grating demodulator (10) via the optical cable (9); the power supply unit (11) provides power to the fiber optic Bragg grating demodulator (10); the fiber optic Bragg grating demodulator (10) transmits the collected data to the monitoring and early warning platform (12) via wireless transmission; the monitoring and early warning platform (12) collects and processes the data to extract information on the amount of settlement, draws a settlement curve, analyzes the settlement trend, and monitors the data according to preset data quality standards and rules; once the data is found to be abnormal or exceeds a preset range, an alarm is immediately issued, thereby providing a scientific basis for the safe operation and maintenance of the monitored structure; the data can also be sent to the remote monitoring center (13) and the mobile terminal (14) to issue accident warnings in a timely manner.

2. A section settlement monitoring system based on fiber grating sensor according to claim 1, characterized in that: The rigid support (1) is a gantry-shaped structure, comprising a settlement rigid beam (102), and two simply supported legs (101) located at both ends of the settlement rigid beam (102), wherein a long strip-shaped simply supported base (103) is provided at the bottom of the two simply supported legs (101), and a first rotating shaft (104) is provided at the center position where the two simply supported legs (101) are connected to the settlement rigid beam (102), and the first rotating shaft (104) passes through a first axial hole (501) provided in the inclinometer rigid beam (5).

3. A section settlement monitoring system based on fiber grating sensor according to claim 2, characterized in that: A second rotating shaft (702) is provided on the upper part of the inclinometer leg column (701) of the inclinometer leg (7), and the second rotating shaft (702) can slide flexibly in the slot (502); a plate-shaped bottom plate (703) is provided at the bottom of the inclinometer leg column (701), and the hook pulley (8) is fixed on the second rotating shaft (702).

4. A section settlement monitoring system based on fiber grating sensor according to claim 3, characterized in that: The simply supported legs (101), the settlement rigid beams (102) and the inclinometer legs (7) are all square rod-shaped or plate-shaped structures.

5. A section settlement monitoring system based on fiber grating sensor according to claim 4, characterized in that: The monitoring anchor point (4) comprises a mounting base (401), on which a fixing connection device (402) is provided; the mounting base (401) of the monitoring anchor point (4) and the monitored component are firmly fixed to the ground by means of expansion screws, pre-embedding, and manufacturing a foundation.

6. A section settlement monitoring system based on fiber grating sensor according to claim 4, characterized in that: The hook pulley (8) comprises a hook (8-01), a pulley shaft (8-02), a bearing (8-03) and a bearing sleeve (8-04); the hook (8-01) is fixed on the outer diameter of the bearing sleeve (8-04); the bearing sleeve (8-04) is embedded in the bearing (8-03); and the bearing (8-03) and the pulley shaft (8-02) are in rolling connection.

7. A method for monitoring cross-section settlement based on a fiber Bragg grating sensor, implemented by a cross-section settlement monitoring system based on a fiber Bragg grating sensor as claimed in any one of claims 3 to 6, characterized in that: The cross-section settlement monitoring method comprises the following steps: Step S1, in a scene where cross-section settlement monitoring is required for a key section with a tunnel passing through, a road with a culvert under construction, or a cast-in-place box girder support, the cross-section settlement monitoring system is set at a cross-section with a settlement risk, with two simply supported legs (101) on both sides of the settlement monitoring area, and a simply supported base (103) is simply supported by the ground; at a measurement starting position, the center line of the simply supported legs (101) is perpendicular to the ground, and the two inclinometer legs (7) are arranged at a horizontal position where no settlement is set, and are distributed outside the two simply supported legs (101), the center line of the inclinometer legs (7) is perpendicular to the ground, and the center line of the settlement rigid beam (102) is perpendicular to the ground; Step S2, setting the center point of the left first rotating shaft (104) as point A, the center point of the right first rotating shaft (104) as point B, the projection of A onto the plane below the simply supported base (103) as point D, the projection of B onto the plane below the simply supported base (103) as point C, the center point of the left second rotating shaft (702) of the inclinometer leg (7) as point E, the center point of the right second rotating shaft (702) of the inclinometer leg (7) as point F, the projection of E onto the plane below the bottom plate (703) as point H, and the projection of F onto the plane below the bottom plate (703) as point G; the center point of the left first displacement sensor as W1; the center point of the left second displacement sensor as W2... the projection of the center point W1 of the left first displacement sensor onto the plane below the monitoring anchor point as W01; the projection of the center point of the left second displacement sensor onto the plane below the monitoring anchor point as W02; Step S3, the initial measurement position AD=BC=EH=FG=h1; AB=CD=l1, AE=BF=l 2, The uniformly distributed gap between displacement meters on the settlement rigid beam (102) is a, W1W 01 =W2W 02 ... = c; Step S4, when settlement occurs between AD and BC, the horizontal line inclination angle of the left inclination sensor (6) measured on the left inclination measuring rigid beam (5) is θ 左 , the displacement sensor (2) on the left side measures the displacement λ 左 The measured inclination angle between the left inclination sensor (6) of the right inclinometer rigid beam (5) and the horizontal line is θ 右 , the displacement sensor (2) on the left side measures the displacement λ 右 ; The data measured by the displacement sensor (2) on the settlement rigid beam (102) are respectively: c1, c2... from left to right; It can be calculated that: AE=l 2+ λ 左 ,BF=l 2+ λ 右 ; Point A sinking = Point D sinking = (l 2+ λ 左 )×Sinθ 左 ; Point B sinking = Point C sinking = (l 2+ λ 右 )×Sinθ 右 ; The calculations show that: The angle between AB and the horizontal is θ 中 =arcsin[(|λ 左 -λ 右 |) / l1]; sinth 中 =(|λ 左 -l 右 |) / l1; The sinking of point W1 relative to point A = c × sinθ 中 =c×[(|λ 左 -λ 右 |) / l1]; The sinking of point W2 relative to point A = 2c × sinθ 中 =2c×[(|λ 左 -λ 右 |) / l1]; …… Absolute sinking of point W1 = sinking of point A + sinking of point W1 relative to point A = (l 2+ λ 左 )×Sinθ 左 +c×[(|λ 左 -λ 右 |) / l1]; Absolute sinking of point W2 = sinking of point A + sinking of point W2 relative to point A = (l 2+ λ 左 )×Sinθ 左 +2c×[(|λ 左 -λ 右 |) / l1]; …… According to the sedimentation rule, W1 and W 01 , W2 and W 02 ...It is not necessary to consider that its projection position along the AD and BC directions will produce relative sliding; W 01 Absolute sinking of point = Absolute sinking of point W1 + (h1 + c1) × cosθ 中 =(l 2+ λ 左 )×Sinθ 左 +c×sinθ 中 + ＝ (l 2+ λ 左 )×Sinθ 左 +c×sin{arcsin[(|λ 左 -λ 右 | / l1)]}+c1; W 02 Absolute sinking of point = Absolute sinking of point W2 + (h1 + c2) × cosθ 中 =(l 2+ λ 左 )×Sinθ 左 +2c×sinθ 中 =(l 2+ λ 左 )×Sinθ 左 +2c×sin{arcsin[(|λ 左 -λ 右 | / l1)]}+c2; Thus, the settlement data of each point D, W01, W02, W03 ... C can be obtained, and a settlement curve can be drawn based on the data; all displacement sensors (2) and inclination sensors (6) are connected to a fiber optic Bragg grating demodulator (10) through an optical cable (9), and a power supply unit (11) provides power for the fiber optic Bragg grating demodulator (10); the fiber optic Bragg grating demodulator (10) transmits the collected data to a monitoring and early warning platform (12) via wireless transmission, and the monitoring and early warning platform (12) collects and processes the data to extract information on the settlement amount, draws a settlement curve, analyzes the settlement trend, and monitors the data according to preset data quality standards and rules. Once the data is found to be abnormal or exceeds the preset range, an alarm will be immediately issued, providing a scientific basis for the safe operation and maintenance of the monitored structure; the data can also be sent to a remote monitoring center (13) and a mobile terminal (14) to issue accident warnings in a timely manner.

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