A method for monitoring the deflection of a high flume

Abstract

The present application relates to the field of structural deflection monitoring, and particularly relates to a high and large flume deflection monitoring method based on static level, which comprises a monitoring device and a flume midspan deflection acquisition method using the monitoring device; the monitoring device comprises a flexible static level tank and a liquid level observer; the flexible static level tank is laid on the top of a straight wall section on one side of a target flume, and water is stored in the flexible static level tank; three measuring points are arranged on the flexible static level tank, and the three measuring points are respectively located at the support and the midspan of the target flume; each measuring point is provided with a liquid level observer; the flume midspan deflection acquisition method comprises the following steps: calculating the rigid body displacement δ1 of the target flume midspan, calculating the relative displacement δ2 of the target flume midspan and one end support, δ = δ2- δ1, and the bending deformation δ is the midspan deflection; compared with the prior art, the present application is less affected by uneven ground subsidence, has smaller error, higher precision, and is convenient to operate and maintain.

Description

Technical Field

[0001] This invention relates to the field of structural deflection monitoring, and more particularly to a method for monitoring the deflection of tall aqueducts based on static leveling. Background Technology

[0002] An aqueduct is an elevated water channel that transports water across rivers, valleys, depressions, and roads. It is commonly used for irrigation, flood control, and sediment removal; large aqueducts can also be navigable.

[0003] As a common structure in water diversion projects, the structural safety of aqueducts has become an increasingly important concern in the construction and operation of these projects, especially with the continuous increase in the scale and distance of water diversion. Mid-span deflection of an aqueduct reflects the degree of bending of the beam after it bears its own weight and the weight of water, and is a crucial deformation indicator for the structural safety of the aqueduct. Therefore, monitoring the deflection of the aqueduct is usually necessary.

[0004] Large aqueducts, due to their large cross-sectional dimensions and high bending stiffness, exhibit relatively small deflections under gravity, typically around a few millimeters. Conventional measurement methods, such as levels and total stations, generally have an accuracy of 1-2 millimeters. This accuracy decreases further as the aqueduct's height and observation distance increase, making accurate observation difficult. Moreover, these methods are easily affected by terrain or obstacles, further limiting their application.

[0005] For aqueducts with low overhead heights, or prototype test aqueducts located near the ground, deflection monitoring can employ convergent monitoring methods. This involves using dial gauges or joint gauges to measure changes in the relative distance between the aqueduct and the ground, thus obtaining the mid-span deflection. While this method offers high resolution, it is significantly affected by the ground reference point. Specifically, under vertical loads such as self-weight and water weight, the ground settles, causing the ground reference point to move, introducing errors into the measurement results. In particular, the difference in settlement between the reference points at both ends of the aqueduct and the mid-span reference point means that the deflection obtained from the mid-span measuring point includes rigid body displacement. This rigid body displacement is not caused by bending stress and can introduce errors into deflection observation and stress assessment of the aqueduct body.

[0006] Therefore, the above problems urgently need to be solved. Summary of the Invention

[0007] This invention aims to address the problems of large errors and limitations in monitoring tall aqueducts in current aqueduct deflection monitoring methods.

[0008] This invention provides the following technical solution: a method for monitoring the deflection of a tall aqueduct, including a monitoring device and a method for obtaining the mid-span deflection of the aqueduct using the monitoring device;

[0009] The monitoring device includes a flexible hydrostatic leveling trough and a liquid level observer. The flexible hydrostatic leveling trough is laid on the top of the straight wall section on one side of the target aqueduct. The flexible hydrostatic leveling trough is always in close contact with the top surface of the straight wall section, and water is stored in the flexible hydrostatic leveling trough. Three measuring points are arranged on the flexible hydrostatic leveling trough. The three measuring points are located at the support and the middle of the span of the target aqueduct, respectively, and a liquid level observer is installed at each measuring point.

[0010] Methods for obtaining the mid-span deflection of an aqueduct include:

[0011] S1; Calculate the rigid body displacement δ1 in the middle of the target aqueduct: The rigid body displacement δ1 is generated by the uneven settlement of the two supports. Process the data of the measuring points at the two supports and calculate the settlement difference δ1' between the two supports. The rigid body displacement δ1 is equal to half of the settlement difference δ1' between the two supports, that is, δ1=0.5δ1'.

[0012] S2; Calculate the relative displacement δ2 between the mid-span and one end support of the target aqueduct: Process the data of the measuring points at one end support and the mid-span, and calculate the settlement difference between the two measuring points, i.e., δ2.

[0013] S3; Calculate the bending deformation δ at the mid-span of the target aqueduct: The relative displacement δ2 at the mid-span of the target aqueduct includes the rigid body displacement δ1 and the bending deformation δ, therefore δ=δ2-δ1, and the bending deformation δ is the mid-span deflection.

[0014] Furthermore, the liquid level observer includes a float, a vertical rod with graduations on the float, a magnetic ring, and a camera. The magnetic ring is fixed to the wall of the flexible hydrostatic leveling tank. The vertical rods at the top and bottom of the float pass through the magnetic ring without contact. The vertical rods and the magnetic ring are magnetically repelled horizontally but have no resistance vertically. The camera is installed above the liquid surface inside the flexible hydrostatic leveling tank. When the flexible hydrostatic leveling tank deforms with the target aqueduct, the float and the vertical rod rise and fall with the liquid level. The camera records the change in the graduation value of the vertical rod relative to the magnetic ring. The camera is connected to a remote image receiving device.

[0015] Furthermore, it also includes a liquid replenishment device, which includes a water filling chamber and an air pump. The liquid replenishment device is installed as a whole at the bottom of the target aqueduct. The water filling chamber is sealed inside, with a water inlet with a valve reserved above the liquid level and a water outlet with a valve reserved below the liquid level. The water outlet is connected to a flexible static leveling tank via a liquid replenishment pipe. The air pump is connected to the water filling chamber by a sealed air circuit, and a valve is provided in the sealed air circuit.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] (1) The present invention uses a flexible static leveling trough, which can be coordinated with the deformation and bending of the top beam of the aqueduct, and the water in the trough is free of air bubbles, effectively eliminating errors, transmitting pressure, and maintaining the liquid level.

[0018] (2) The flexible static leveling tank of the present invention is equipped with a liquid replenishment device. When the liquid in the tank is lost due to evaporation or other reasons, the liquid replenishment device can replenish the liquid at the bottom of the pier, avoiding high-altitude operations and making maintenance convenient.

[0019] (3) This invention proposes a novel liquid level observer, which is located at the measuring point in a hydrostatic leveling flume. It includes a float, a vertical rod with graduations on the float, and a magnetic ring. The vertical rod and the magnetic ring are mutually repelled in the horizontal direction to prevent contact resistance. There is no resistance in the vertical direction, which makes it easy for the float to float up and down with the water surface. The liquid level observer uses machine vision technology to identify changes in the vertical rod graduations and observe changes in the liquid level height at the measuring point. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 This is a schematic diagram showing the location of the static leveling flume of the present invention;

[0022] Figure 3 This is a schematic diagram of the liquid level observer of the present invention;

[0023] Figure 4 This is a schematic diagram illustrating the principle of the static leveling flume of the present invention;

[0024] Figure 5 This is a schematic diagram of the fluid replenishment device of the present invention;

[0025] In the diagram: 1-Flexible static leveling flume; 2-Liquid level observer; 201-Float ball; 202-Vertical rod; 203-Magnetic ring; 204-Camera; 3-Liquid replenishment device; 301-Outlet; 302-Water inlet; 303-Sealed air passage; 304-Water filling chamber; 305-Air pump. Detailed Implementation

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] like Figure 1 , Figure 2 , Figure 4 As shown: A method for monitoring the deflection of a tall aqueduct, including a monitoring device and a method for obtaining the mid-span deflection of the aqueduct using the monitoring device;

[0028] The monitoring device includes a flexible static leveling flume 1 and a liquid level observer 2. The flexible static leveling flume 1 has an open top and is laid on top of the straight wall section of the target aqueduct. The flexible static leveling flume 1 is always in close contact with the top surface of the straight wall section. The flexible static leveling flume 1 is flexible and can coordinate with the deformation and bending of the aqueduct's top beam. The "flexibility" refers to its flexibility relative to the aqueduct. The static leveling flume itself has a certain degree of rigidity, which can maintain its stability when not subjected to the aqueduct's force. Water is stored inside the flexible static leveling flume 1. Three measuring points are arranged on the flexible static leveling flume 1, located at the support and mid-span of the target aqueduct, respectively. A liquid level observer 2 is installed at each measuring point. The three liquid level observers 2 measure the changes in liquid level at the aqueduct support and mid-span, respectively.

[0029] When a flexible hydrostatic leveling flume deforms, each measuring point will experience displacement. Methods for obtaining the mid-span deflection of the flume include:

[0030] S1; Calculate the rigid body displacement δ1 in the middle of the target aqueduct: The rigid body displacement δ1 is caused by the uneven settlement of the two supports, not by the structural deformation caused by bending stress. Process the data of the measuring points at the two supports and calculate the settlement difference δ1' between the two supports. The rigid body displacement δ1 is equal to half of the settlement difference δ1' between the two supports, that is, δ1=0.5δ1'.

[0031] S2; Calculate the relative displacement δ2 between the mid-span and one end support of the target aqueduct: Process the data of the measuring points at one end support and the mid-span, and calculate the settlement difference between the two measuring points, i.e., δ2.

[0032] S3; Calculate the bending deformation δ at the mid-span of the target aqueduct: The relative displacement δ2 at the mid-span of the target aqueduct includes the rigid body displacement δ1 and the bending deformation δ, therefore δ=δ2-δ1, and the bending deformation δ is the mid-span deflection.

[0033] like Figure 3 As shown: The liquid level observer 2 includes a float 201, a vertical rod 202 with graduations on the float, a magnetic ring 203, and a camera 204. The magnetic ring 203 is fixed to the wall of the flexible hydrostatic leveling tank 1. The vertical rod 202 at the top and bottom of the float 201 passes through the magnetic ring 203 without contact. The vertical rod 202 and the magnetic ring 203 are mutually repelled horizontally by magnetic forces but have no resistance vertically, allowing the vertical rod 202 to float up and down with the float 201. The camera 204 is installed above the liquid surface in the flexible hydrostatic leveling tank 1. When the flexible hydrostatic leveling tank deforms with the target aqueduct, the float 201 and the vertical rod 202 rise and fall with the liquid level changes. The camera 204 records the change in the graduation value of the vertical rod 202 relative to the magnetic ring 203. The camera 203 is connected to a remote image receiving device. The liquid level observer uses machine vision technology to identify changes in the vertical rod graduations and observes changes in the liquid level height at the measuring point.

[0034] like Figure 5As shown, it also includes a liquid replenishment device 3, which comprises a water filling chamber 304 and an air pump 305. The entire liquid replenishment device is installed at the bottom of the target aqueduct. The water filling chamber 304 is internally sealed, with a water inlet 302 with a valve reserved above the liquid level and a water outlet 301 with a valve reserved below the liquid level. The water outlet 301 is connected to the flexible static leveling tank 1 via a liquid replenishment pipe 306. The air pump 305 is connected to the water filling chamber 304 via a sealed air passage 303, which is equipped with a valve. When the liquid in the static leveling tank is lost due to evaporation or other reasons, the liquid replenishment device replenishes the liquid by creating a pressure difference, ensuring that the liquid in the static leveling tank is sufficient.

[0035] This invention proposes a method for monitoring the deflection of tall aqueducts. The monitoring device accurately monitors aqueduct deflection without the influence of air bubbles and effectively solves problems related to evaporation replenishment and high-altitude observation. This invention uses a static leveling flume instead of a conventional static level instrument. The flume is free of air bubbles, effectively transmitting pressure and maintaining a level liquid surface, avoiding errors caused by air bubbles. Simultaneously, this invention proposes a novel liquid level observation device. The magnetic ring and the vertical rod of the float exhibit magnetic repulsion in the horizontal direction, while offering no resistance in the vertical direction, ensuring the float only moves up and down, accurately observing liquid level changes at the measuring point. Furthermore, this invention places the replenishment device of the static leveling flume at the bottom of the pier, achieving replenishment by creating a pressure difference at the bottom of the pier, avoiding high-altitude operations and facilitating maintenance. This invention uses a three-point measuring method to observe the relative positions of the two supports and the mid-span of the aqueduct, calculating the rigid displacement and relative displacement of the aqueduct, and ultimately deducing the bending deformation of the aqueduct, reducing the impact of uneven settlement of the supports on the aqueduct deflection observation. Compared with existing technologies, this invention is less affected by uneven ground settlement, has smaller errors, higher accuracy, and is easier to operate and maintain.

[0036] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for monitoring the deflection of tall aqueducts, characterized in that: This includes a monitoring device and a method for obtaining the mid-span deflection of the aqueduct using the monitoring device; The monitoring device includes a flexible static leveling trough (1) and a liquid level observer (2). The flexible static leveling trough (1) is laid on the top of the straight wall section on one side of the target aqueduct. The flexible static leveling trough (1) is always in close contact with the top surface of the straight wall section. Water is stored in the flexible static leveling trough (1). Three measuring points are arranged on the flexible static leveling trough (1). The three measuring points are located at the support and the middle of the span of the target aqueduct, respectively. A liquid level observer (2) is installed at each measuring point. Methods for obtaining the mid-span deflection of an aqueduct include: S1； Calculate the rigid body displacement at the mid-span of the target aqueduct rigid body displacement This is caused by uneven settlement between two supports. Data from measuring points at the two supports are processed to calculate the differential settlement between them. rigid body displacement Equal to the differential settlement between the two supports One-half, that is ; S2; Calculate the relative displacement between the mid-span of the target aqueduct and one end support. : Process the data from one end support and the mid-span measuring point to calculate the settlement difference between the two measuring points, i.e. ; S3; Calculate the bending deformation at the mid-span of the target aqueduct. Relative displacement at the mid-span of the target aqueduct Including rigid body displacement and bending deformation ,therefore Bending deformation This refers to the mid-span deflection; The liquid level observer (2) includes a float (201), a vertical rod (202) with graduations on the float, a magnetic ring (203), and a camera (204). The magnetic ring (203) is fixed on the wall of the flexible static leveling tank (1). The vertical rods (202) at the top and bottom of the float (201) pass through the magnetic ring (203) without contact. The vertical rod (202) and the magnetic ring (203) are mutually repelled in the horizontal direction and have no resistance in the vertical direction. The camera (204) is installed above the liquid surface in the flexible static leveling tank (1). When the flexible static leveling tank deforms with the target trough, the float (201) and the vertical rod (202) rise and fall with the change of the liquid level. The camera (204) records the change of the graduation value of the vertical rod (202) relative to the magnetic ring (203). The camera (204) is connected to an image remote receiving device.

2. The method for monitoring the deflection of a high aqueduct according to claim 1, characterized in that: It also includes a liquid replenishment device (3), which includes a water filling chamber (304) and an air pump (305). The liquid replenishment device is installed as a whole at the bottom of the target aqueduct. The water filling chamber (304) is sealed inside. A water inlet (302) with a valve is reserved above the liquid level and a water outlet (301) with a valve is reserved below the liquid level. The water outlet (301) is connected to the flexible static leveling tank (1) via a liquid replenishment pipe (306). The air pump (305) is connected to the water filling chamber (304) by a sealed air passage (303). A valve is provided in the sealed air passage (303).

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