A wading long-line steel trestle monitoring system and monitoring method

Abstract

The application relates to the field of wading bridge monitoring, and particularly discloses a wading long-line steel trestle monitoring system and a monitoring method, which comprises a reference unit, a sensor unit and a steel trestle installation unit, the reference unit comprises a reference stand column arranged in a water body, the sensor unit comprises a reference inclination sensor, a steel trestle reference inclination sensor and a pull rope displacement sensor; the reference inclination sensor is arranged on the reference stand column, the steel trestle reference inclination sensor is arranged on the steel trestle, the pull rope displacement sensor is arranged on the steel trestle, and a pull rope in the pull rope displacement sensor is arranged at the top end of the reference stand column. The application aims to solve the technical problem of how to accurately monitor the displacement condition of the steel trestle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wading bridge monitoring, and specifically discloses a wading long-line steel trestle monitoring system and a monitoring method. BACKGROUND

[0002] Steel trestle is an indispensable temporary structure in bridge construction or water construction, which provides a traffic channel, a mechanical arrangement platform and an overhead working surface for the construction site. Especially in complex hydrogeological conditions such as deep rivers and coastal areas, the steel trestle bears multiple functions such as material transportation, equipment support and personnel passage. Due to its temporary nature, the steel trestle usually adopts standardized and assembled components in design to pursue rapid erection and economy. However, this temporary nature does not mean that its safety can be reduced. On the contrary, the steel trestle is continuously subjected to the test of complex environment such as dynamic water flow impact, ship impact risk, heavy engineering vehicle load, and water level fluctuation caused by flood and tide during the entire construction period. Once instability or damage occurs, it may cause serious engineering accidents, personnel casualties and huge economic losses, and have a disastrous impact on the progress of the entire project. Therefore, it is of extremely important practical significance to conduct real-time, effective and reliable safety monitoring on the key parts of the steel trestle.

[0003] The patent No. 202410750950.X discloses a steel trestle deformation monitoring method based on non-contact full-field measurement technology DIC, which comprises the following steps: 1. Formulate the DIC monitoring scheme according to the actual working condition; 2. According to the monitoring points determined by the DIC monitoring scheme, set up a scaffold beside the monitored area of the monitoring points; 3. Install monitoring equipment on the scaffold, and make the monitoring equipment face the monitored area; 4. Make DIC speckle patterns on the surface of the monitored area of the steel trestle; 5. Install displacement sensors beside the monitored area of the steel trestle; 6. Formulate DIC automatic monitoring algorithm, and internally test the DIC automatic monitoring algorithm; 7. Run the DIC automatic monitoring algorithm formally. The present application relates to the field of construction trestle health monitoring technology, and can solve the problems of the existing steel trestle deformation monitoring method, such as needing to contact the measured object, only measuring single-point data, low data collection efficiency, complex installation and maintenance, high cost and low automation degree.

[0004] The steel trestle of the above-mentioned patent is set on land, the reference point position is relatively easy to set, and the reference point position is not easy to deviate after being set. However, the steel trestle in the present application is set in a wading area, the underwater condition of the wading area is complex, and it is difficult to find a reference point for measurement, resulting in inaccurate monitoring results. SUMMARY

[0005] Therefore, the present application aims to provide a wading long-line steel trestle monitoring system and a monitoring method to solve the technical problem of how to accurately monitor the inclination of the steel trestle.

[0006] To achieve the above object, the present application provides the following technical solutions:

[0007] A wading long-line steel trestle monitoring system, comprising a reference unit, a sensor unit and a steel trestle installation unit, the reference unit comprising a reference column arranged in a water body, the sensor unit comprising a reference inclination sensor, a steel trestle reference inclination sensor and a pull rope displacement sensor; the reference inclination sensor is arranged on the reference column, the steel trestle reference inclination sensor is arranged on the steel trestle, and the pull rope displacement sensor is arranged on the steel trestle, and a pull rope in the pull rope displacement sensor is arranged at the top end of the reference column.

[0008] In the prior art, the steel trestle is less monitored, but the bridge monitoring technology is more, generally more laser sensors, strain gauges and grating sensors, etc. These sensors are installed on the bridge and can play a real-time monitoring role, but these sensors are not suitable for monitoring the water steel trestle, the reasons are as follows: 1. Laser sensors are easily affected by the external environment, and are easily damaged in the long-term water environment, and are very sensitive to long-term monitoring, which is easy to produce many noise points; 2. Strain gauges, grating sensors, etc. are also very easy to be affected by the vibration of the steel trestle, and the steel trestle is a temporary structure, which is less stable than the completed bridge, and the vibration is more frequent; 3. It is difficult to determine the reference point, the distance between the shore and the center of the steel trestle is far, and the soil on the shore is easy to settle, resulting in inaccurate reference point; 4. For the temporary structure of the steel trestle, the monitoring method of the above-mentioned sensor has high cost and poor economy. In the prior art, the monitoring is also carried out by satellite positioning, and the error of satellite positioning is still large, most of which are in the process of theoretical research, and are not suitable for the field situation.

[0009] In the present scheme, the reference unit is inserted into the water body, and the reference column of the reference unit is close to the bridge column of the steel trestle, so that the monitoring is more convenient and accurate. Then the pull rope displacement sensor is arranged on the steel trestle and the pull rope is bound on the reference column. The pull rope displacement sensor has the advantages of: 1. Accurate monitoring; 2. Not easy to be affected by the environment (rainy days or haze, etc.); 3. Low price. In the present scheme, a plurality of bridge columns can be monitored. At the same time, the reference inclination sensor is arranged on the reference column in the present scheme, which can monitor the deviation of the reference column, and the displacement result of the pull rope displacement sensor is compensated according to the detection structure.

[0010] Optionally, the steel trestle comprises a bridge column, the reference column is arranged behind the bridge column along the water flow direction, the pull rope displacement sensor is aligned with the reference column, and the height of the pull rope displacement sensor is higher than that of the reference column; after the pull rope of the pull rope displacement sensor is connected with the reference column, the pull rope forms an angle of 45° with the horizontal plane. With the scheme, after the positions of the reference column and the pull rope displacement sensor are set in advance, the difficulty of calculation and analysis can be reduced. Meanwhile, the pull rope displacement sensor is arranged behind the bridge column, so that the impact of the water flow on the reference column can be reduced, and the position of the reference column can be prevented from being changed due to the scouring of the water flow.

[0011] Optionally, the rear end of the bridge column is provided with a V-shaped flow baffle, the height of the flow baffle is 0.3-0.7 m, and the end of the flow baffle away from the bridge column is located on the rear side of the reference column. In the scheme, the flow baffle is provided, and the height of the flow baffle is also not high. The reason is that in the water flow, only the surface water flow has a relatively large flow rate because the distance from the riverbed is far, and the flow rate below the water body is relatively low, so the flow baffle does not need to be set too large. The flow baffle can reduce the influence of the water flow on the reference column.

[0012] Optionally, the upper portion of the reference column is formed with a mounting cavity, the reference inclination sensor is arranged on the mounting cavity, and the mounting cavity is provided with a sealing plate. With the scheme, the reference inclination sensor is arranged on the upper portion of the reference column, so that the reference inclination sensor can be prevented from being submerged by the water flow. Meanwhile, the sealing plate is arranged, so that even if the water body rises, the reference inclination sensor can be prevented from being in contact with the water flow. The pull rope displacement sensor is arranged above the bridge column, so that the pull rope displacement sensor will not be submerged, and even if the pull rope enters the water, the monitoring result will not be affected.

[0013] Optionally, the flow baffle is provided with a support, and the support is used for mounting a line.

[0014] Optionally, the sensing unit further comprises a fiber grating static hydrostatic level sensor, the fiber grating static hydrostatic level sensor comprises a level sensor body, a liquid storage tank and a reference base, the reference base is arranged underwater, the liquid storage tank is arranged on the reference base, and the level sensor body is arranged on the column body. The scheme is mainly used for monitoring the settlement of the reference column. The reference base is arranged, and the reference base needs to be constructed in a small cofferdam mode to ensure the stability and prevent the reference base from moving abnormally underwater. After the bridge is completed, the reference base can also serve as a reference point for various sensors.

[0015] Optionally, the reference column comprises a column body, the lower end of the column body is formed with a tapered portion, the column body is divided into an upper hollow portion and a lower hollow portion, the tapered portion is located in the lower hollow portion, a telescopic cylinder is arranged in the upper hollow portion, the top of the telescopic cylinder is provided with a top platform, the top platform is in sliding and sealing connection with the inner wall of the upper hollow portion, and a hook connected with the pull rope is arranged on the upper end of the top platform.

[0016] In the scheme, the reference column is fixed in the riverbed in the form of a steel pipe pile, so a tapered part is arranged at the bottom of the reference column, and the lower hollow part is arranged to enable the soil layer to enter the reference column when the reference column is driven into the riverbed. The upper hollow part is arranged with a telescopic cylinder, which can push the top platform out to compensate for the error caused by the settlement of the reference column.

[0017] 8. A monitoring method of a wading long-line steel trestle monitoring system, comprising the following steps:

[0018] S1, monitoring the settlement of the reference column by the fiber Bragg grating static level sensor, and if the reference column settles, starting the telescopic cylinder to move the top platform upward for compensation;

[0019] S2, monitoring the data of the reference inclination sensor and the pull rope displacement sensor, and calculating the relative displacement change between the bridge column and the reference column;

[0020] S3, establishing a coordinate system:

[0021] Origin O: reference point position;

[0022] X-axis: horizontal direction, pointing to the initial position of the steel pipe pile;

[0023] Y-axis: horizontal direction, perpendicular to the X-axis;

[0024] Z-axis: vertical upward direction;

[0025] Initial state parameters:

[0026] Initial length of pull rope: L0;

[0027] Initial direction angle of pull rope: pitch angle a0=45°, azimuth angle b0=0°;

[0028] Initial attitude of reference point: roll angle F0=0°, pitch angle q0=0°, yaw angle w0=0°;

[0029] S4, rotation matrix of reference column:

[0030] Euler angles measured by the reference inclination sensor are converted into a rotation matrix:

[0031]

[0032] Wherein each basic rotation matrix is:

[0033]

[0034]

[0035]

[0036] S5, pull rope direction vector calculation:

[0037]

[0038] Wherein the initial direction vector:

[0039]

[0040] S6, bridge column displacement vector calculation:

[0041] Bridge column current position vector:

[0042]

[0043] Displacement change:

[0044]

[0045] Unfolded into component form:

[0046]

[0047]

[0048]

[0049] The working principle and beneficial effects of the present scheme are:

[0050] The present scheme adopts relatively simple and low-cost equipment to monitor the inclination and displacement of the long-line wading steel trestle. First, the reference column is arranged in the present scheme, and the reference column is arranged at the rear side of the bridge column of the steel trestle, reducing the influence of water flow, and further arranging the flow baffle to further reduce the influence of water flow, avoiding the offset of the reference column, and ensuring that the reference point of the reference column is constant. At the same time, even if the reference column is offset, it can be detected by the reference inclination sensor, and then compensated by calculation, and if the reference column is settled, it can be detected by the fiber Bragg grating static level sensor and compensated by the extension of the telescopic cylinder. The pull rope displacement sensor used in the present scheme can monitor the displacement change between the bridge column and the reference column, and the pull rope displacement sensor will not be affected by fog, rain, temperature and humidity, etc. It is very suitable for the environment around the water body, and the installation of the reference column can also use the same steel pipe pile installation method as the installation of the steel trestle, and the construction method is simple and convenient. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 The structural schematic diagram of the embodiment is shown in the figure;

[0052] Fig. 2 The structural schematic diagram of the bridge column and the reference column is shown in the figure;

[0053] Fig. 3 Part structure sectional view of reference column.

[0054] The reference signs in the drawings are as follows: steel trestle 1, reference column 2, reference base 3, bridge column 4, pull rope displacement sensor 5, flow deflector 6, top platform 7, level sensor body 8, tapered portion 9, liquid storage tank 10, hook 11, column body 12, lower hollow portion 13, upper hollow portion 14, reference inclination sensor 15, telescopic cylinder 16, sealing plate 17, wire hole 18, drainage hole 19. DETAILED DESCRIPTION

[0055] The following is further described in detail through specific embodiments:

[0056] EMBODIMENT

[0057] A wading long-line steel trestle 1 monitoring system, as shown in the figure, comprises a reference unit, a sensor unit and a steel trestle 1 installation unit. Figs. 1-3

[0058] The steel trestle 1 comprises a bridge column 4. The rear end of the bridge column 4 is provided with a V-shaped flow deflector 6, the height of the flow deflector 6 is 0.3-0.7m, and the end of the flow deflector 6 away from the bridge column 4 is located at the rear side of the reference unit. A support is provided on the flow deflector 6, which is used to install the line. The support structure is simple and not drawn in the figure.

[0059] The reference unit comprises a reference column 2 arranged in the water body, the reference column 2 is arranged behind the bridge column 4 in the direction of the water flow, and the reference column 2 is installed by the way of steel pipe pile. The reference column 2 comprises a column body 12, the lower end of the column body 12 forms a tapered portion 9, the column body 12 is divided into an upper hollow portion 14 and a lower hollow portion 13, the tapered portion 9 is located in the lower hollow portion 13, and a drainage hole 19 is arranged at the top of the lower hollow portion 13. A telescopic cylinder 16 is arranged in the upper hollow portion 14, the top of the telescopic cylinder 16 is provided with a top platform 7, the top platform 7 is in sliding sealing connection with the inner wall of the upper hollow portion 14, and a hook 11 connected with a pull rope is arranged at the upper end of the top platform 7. An installation cavity is formed at the upper part of the upper hollow portion 14, a reference inclination sensor 15 in the sensor unit is arranged on the installation cavity, and a sealing plate 17 is arranged on the installation cavity. A wire hole 18 is arranged on the sealing plate 17, which is used to pass through the line and seal.

[0060] ​The sensor unit comprises a reference inclination sensor 15, a steel trestle 1 reference inclination sensor 15, a pull rope displacement sensor 5 and a fiber grating static level sensor. The reference inclination sensor 15 is arranged on the reference column 2, the steel trestle 1 reference inclination sensor 15 is arranged on the steel trestle 1, the pull rope displacement sensor 5 is arranged on the steel trestle 1, and the pull rope in the pull rope displacement sensor 5 is arranged on the top platform 7 of the reference column 2. The pull rope displacement sensor 5 is aligned with the reference column 2, and the height thereof is higher than that of the reference column 2. After the pull rope of the pull rope displacement sensor 5 is connected with the column, the pull rope forms an angle of 45° with the horizontal plane. The fiber grating static level sensor comprises a level sensor body 8, a liquid storage tank 10 and a reference base 3. The reference base 3 is arranged underwater, and the reference base 3 is constructed in a cofferdam manner. Although this method is time-consuming and laborious, the reference base 3 constructed by this method can be used not only for monitoring the steel trestle 1, but also as a reference point for monitoring the subsequent completed bridge. The liquid storage tank 10 is arranged on the reference base 3, and the level sensor body 8 is arranged on a column body 12.

[0061] A monitoring method of a wading long-line steel trestle 1 monitoring system, comprising the following steps:

[0062] S1, monitoring the settlement of the reference column 2 by the fiber grating static level sensor, and if the reference column 2 settles, starting the telescopic cylinder 16 to move the top platform 7 upward to compensate;

[0063] S2, monitoring the data of the reference inclination sensor 15 and the pull rope displacement sensor 5, and calculating the relative displacement change between the bridge column 4 and the reference column 2;

[0064] S3, establishing a coordinate system:

[0065] Origin O: reference point position;

[0066] X-axis: horizontal direction, pointing to the initial position of the steel pipe pile;

[0067] Y-axis: horizontal direction, perpendicular to the X-axis;

[0068] Z-axis: vertical upward direction;

[0069] Initial state parameters:

[0070] Initial length of pull rope: L0;

[0071] Initial direction angle of pull rope: pitch angle a0=45°, azimuth angle b0=0°;

[0072] Initial attitude of reference point: roll angle F0=0°, pitch angle t0=0°, yaw angle w0=0°;

[0073] S4, rotation matrix of the reference column 2:

[0074] The Euler angle measured by the reference inclination sensor 15 is converted into a rotation matrix:

[0075]

[0076] where each basic rotation matrix is:

[0077]

[0078]

[0079]

[0080] S5, the direction of the pull rope vector calculation:

[0081]

[0082] where the initial direction vector:

[0083]

[0084] S6, the bridge column displacement vector calculation:

[0085] The current position vector of the bridge column:

[0086]

[0087] Displacement change:

[0088]

[0089] Expand to component form:

[0090]

[0091]

[0092]

[0093] In specific implementation:

[0094] The inclination sensor of the steel trestle 1 and the fiber grating static level sensor are two independent sensors and do not participate in displacement calculation. Their function is to monitor the inclination of the bridge column 4 of the steel trestle 1 and the settlement of the reference column 2. The fiber grating static level sensor can use the model: JH-FGD-C2. Other sensors are very mature in technology and belong to very common sensor equipment, so no specific model is recommended.

[0095] In the installation of the reference column 2, the position of the reference column 2 needs to be set in advance, then the pull rope displacement sensor 5 is installed, and finally the hook 11 on the top platform 7 is welded according to the position of the pull rope displacement sensor 5, so as to ensure that the pull rope of the pull rope displacement sensor 5 reaches the preset angle and position.

[0096] Test example:

[0097] The following data is monitored:

[0098] 1. Initial length of pull rope L0=10m

[0099] Length change ΔL=+0.15m

[0100] Reference point inclination: roll Φ=1°, pitch θ=0.5°, yaw ψ=0.3°;

[0101] 2. Calculation steps:

[0102] 2.1 Convert to radians: Φ=0.01745 rad, θ=0.00873 rad, ψ=0.00524 rad

[0103] 2.2 Calculate the rotation matrix components:

[0104]

[0105]

[0106]

[0107] 2.3 Calculate the combined rotation matrix:

[0108]

[0109] 2.4 Calculate the current direction vector:

[0110]

[0111] 2.5 Final displacement result:

[0112]

[0113] The above is only an embodiment of the present application, and the specific structure and characteristics of the scheme are not described in detail. It should be noted that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should be considered as the protection scope of the present application, which will not affect the effect and practicability of the present application.

Claims

1. A wading long-line steel trestle monitoring system characterized by: The application relates to a monitoring system for a wading long-line steel trestle, which comprises a reference unit, a sensor unit and a steel trestle installation unit, wherein the reference unit comprises a reference column arranged in a water body, the sensor unit comprises a reference inclination sensor, a steel trestle reference inclination sensor and a pull rope displacement sensor; the reference inclination sensor is arranged on the reference column, the steel trestle reference inclination sensor is arranged on the steel trestle, the pull rope displacement sensor is arranged on the steel trestle, and a pull rope in the pull rope displacement sensor is arranged at the top end of the reference column; the steel trestle comprises a bridge column, the reference column is arranged behind the bridge column along the water flow direction, the pull rope displacement sensor is aligned with the reference column and has a height higher than that of the reference column, the pull rope in the pull rope displacement sensor is connected with the column, and the pull rope has an angle of 45 DEG with the horizontal plane after the connection; the sensor unit further comprises a fiber grating static level sensor, the fiber grating static level sensor comprises a level sensor body, a liquid storage tank and a reference base, the reference base is arranged underwater, the liquid storage tank is arranged on the reference base, and the level sensor body is arranged on the column body; the reference column comprises a column body, a tapered portion is formed at the lower end of the column body, the column body is divided into an upper hollow portion and a lower hollow portion, the tapered portion is located in the lower hollow portion, a telescopic cylinder is arranged in the upper hollow portion, a top platform is arranged at the top of the telescopic cylinder, the top platform is in sliding sealing connection with the inner wall of the upper hollow portion, and a hook connected with the pull rope is arranged at the upper end of the top platform; a monitoring method of the monitoring system is provided, and the method comprises the following steps: S1, the settlement of the reference column is monitored through the fiber grating static level sensor, and if the reference column settles, the telescopic cylinder is started to move the top platform upward to compensate; S2, the data of the reference inclination sensor and the pull rope displacement sensor are monitored, and the relative displacement change between the bridge column and the reference column is calculated; S3, a coordinate system is established: origin O: reference point position; X axis: horizontal direction, pointing to the initial position of the steel pipe pile; Y axis: horizontal direction, perpendicular to the X axis; Z axis: vertical upward direction; initial state parameters: initial length of the pull rope: L0; initial direction angle of the pull rope: pitch angle alpha0=45 DEG, azimuth angle beta0=0 DEG; initial posture of the reference point: roll angle Phi0=0 DEG, pitch angle theta0=0 DEG, yaw angle psi0=0 DEG; S4, the rotation matrix of the reference column: the Euler angle measured by the reference inclination sensor is converted into a rotation matrix: ； wherein each basic rotation matrix is: ； ； ； S5, the direction vector calculation of the pull rope: ， wherein the initial direction vector is: ， S6, the bridge column displacement vector calculation: the current position vector of the bridge column: ， displacement change: ， expanded into component form: ； ； 。 2. A wading long span steel trestle monitoring system according to claim 1, characterized in that: the rear end of the bridge column is provided with a V-shaped flow deflector, the height of the flow deflector is 0.3-0.7 m, and the end of the flow deflector away from the bridge column is located at the rear side of the reference column.

3. A wading long span steel trestle monitoring system according to claim 2, characterized in that: The upper part of the reference column is formed with a mounting cavity, the reference inclination sensor is arranged on the mounting cavity, and a sealing plate is arranged on the mounting cavity.

4. A wading long span steel trestle monitoring system according to claim 3, characterized in that: A support is arranged on the flow deflector, and the support is used for installing a line.

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