A device and method for measuring three-dimensional displacement vectors inside a rockfill dam

Abstract

The application discloses a kind of rock-fill dam internal three-dimensional displacement vector measuring device and measuring method, including a inner wall is arranged with three rifling grooves and the flexible observation pipeline of outer wall interval arrangement tooth ring;Pipeline robot;Power traction mechanism.Measuring method is mainly through the measurement of internal deformation observation pipeline curve coordinates and pipeline axial deformation, to determine the coordinate change of any point in observation pipeline after dam deformation, to determine the three-dimensional displacement vector in the internal of rock-fill dam.Through the present application, the axial deformation of pipeline curve can be obtained while obtaining the shape of pipeline curve, and then the accurate three-dimensional displacement vector of pipeline is calculated based on the shape of pipeline curve and axial deformation, so that the deformation of each point in the internal of rock-fill dam, including settlement and horizontal displacement, is finally obtained more accurately.

Description

Technical Field

[0001] This invention relates to a settlement monitoring device and method for a rockfill dam, and more particularly to a device and method for measuring the three-dimensional displacement vector inside a rockfill dam. Background Technology

[0002] Currently, the latest method for observing the internal deformation of rockfill dams is based on pipeline measurement robot technology (Chinese Journal of Geotechnical Engineering: 1-8, 2022-07-19, Settlement Measurement Method for High Rockfill Dams Based on Pipeline Measurement Robot). Its basic principle is: first, a flexible observation pipeline that deforms synchronously with the dam body is deployed inside the rockfill dam; second, the pipeline robot is used to measure the curve shape of the deformed pipeline; finally, the internal deformation of the rockfill is determined by comparing the initial curve shape of the pipeline with the deformed curve shape. Figure 1 As shown.

[0003] While pipeline robots can currently observe the shape of pipeline curves, simply comparing the initial curve with the measured curve is insufficient to accurately determine the displacement vector of every point within the pipeline. Taking vertical settlement as an example, if only through... Figure 1 If the difference in elevation between the initial curve and the measured curve at a certain location in the pipeline is used as the settlement value, it assumes that the vector direction of displacement at every point in the pipeline is vertically downward. However, this is not the case in reality. The displacement vector (including direction and magnitude) at each point in the pipeline depends not only on the shape of the curve after the pipeline deforms, but also on the magnitude of the axial deformation of the pipeline, which can be simply described as the stretching or contraction of the pipeline.

[0004] like Figure 2As shown, the initial curve shows a pipe segment of length dL with two endpoints A0 and A1. A0 is the starting point (reference point) of the pipe at the observation house. The displacement vector of point A0 (including vertical settlement and horizontal displacement) is obtained from the external observation system of the dam. It is assumed that its deformed position, measured by the external observation system, is B0, and only vertical settlement h0 has occurred. If the other endpoint A1 only has vertical settlement, then the deformed position of A1 should be B1. In this case, the angle between line segment B0B1 and the horizontal line is θ. The original length of the pipe dL becomes dL / cosθ, and the elongation of this pipe segment is dL(1 / cosθ). -1), and only when the pipe elongation is dL(1 / cosθ-1) can it be guaranteed that point A1 will only experience vertical settlement. However, the elongation of each segment in the pipe is unknown beforehand. When the pipe elongation is less than dL(1 / cosθ-1), point A1 will inevitably not reach point B1. In this case, the deformed position of point A1 may only reach point C1. Alternatively, the pipe elongation may exceed dL(1 / cosθ-1), in which case point A1 may have reached point D1. The vertical settlement of point A1 corresponding to these three different positions are h1, h2, and h3, respectively. This shows that the curve shape after pipe deformation is insufficient to determine the displacement vector of each point in the pipe. The existing robotic observation technology for settlement pipes inside rockfill dams needs further improvement. Summary of the Invention

[0005] Purpose of the invention: To address the above problems, this invention proposes a measuring device and method for measuring the three-dimensional displacement vector inside a rockfill dam, which can accurately obtain the displacement vector direction and magnitude of each point in the pipeline, thereby obtaining a more accurate deformation of each point inside the rockfill dam.

[0006] Technical solution: The technical solution adopted in this invention is a three-dimensional displacement vector measurement device inside a rockfill dam, comprising: a flexible observation pipe with three rifling grooves on the inner wall and toothed rings arranged at intervals on the outer wall; a pipe robot; a power traction mechanism, etc., which are connected by cables, sensors, chips and software to form an overall measurement system.

[0007] The aforementioned flexible pipe with rifling grooves on its inner wall is made of integrally extruded HDPE pipe. Through secondary processing, three rifling grooves with uniform twist angles are machined on the inner wall of the pipe, with an included angle of 120° between each groove. At the same time, toothed rings are arranged at certain intervals on the outer wall of the pipe. Due to the characteristics of the pipe's own material properties, it can maintain a large radial stiffness and is not prone to radial deformation, while its axial stiffness is relatively small, allowing for more freedom in pipe elongation and compression. In addition, the toothed rings arranged at intervals on the outer wall of the pipe can reduce the possibility of relative sliding between the dam material surrounding the pipe and the pipe, thereby improving the synchronization between pipe deformation and dam deformation.

[0008] The pipeline robot's main mechanical structure consists of a main shaft with three independently rotating rods at each end. Each rod has a caster wheel at its end, allowing it to smoothly engage with the rifling grooves on the inner wall of the pipe and move accordingly, driving the rods to rotate around the main shaft, which in turn propels the main shaft forward within the pipe. Using one caster wheel allows for mileage measurement, while using three allows for more accurate and stable measurements. Springs connect the casters to the rods, ensuring the casters remain in contact with the bottom of the rifling grooves. During the robot's movement, the traction force and the force exerted by the rods on the main shaft ensure that the main shaft remains aligned with the pipe's central axis. An electronic equipment compartment is fixed to the main shaft, containing a data acquisition and processing module, a six-axis electronic compass, three angle sensors, and a power module. The data acquisition and processing module is responsible for acquiring and processing all sensor data. The six-axis electronic compass records the azimuth angle of the main shaft's projection onto the horizontal plane and the pitch angle between the main shaft and the direction of gravitational acceleration in real time. Three rotation sensors can record the rotation angles of the three rotating rods at the head end of the main shaft around the main shaft in real time. The power module is responsible for supplying power to all sensors and electronic equipment. After arranging the above four components in the electronic equipment compartment, it should be ensured that the center of gravity of the entire pipeline robot is below the main shaft, so that the main shaft itself does not rotate during the rotation of the rotating rods.

[0009] The power traction device includes a drive motor and an electric winch; the drive motor drives the pull line on the electric winch to pull the pipeline robot forward, and can record the mileage pulled by the pull line in real time.

[0010] This invention proposes a method for measuring the three-dimensional displacement vector of a pipeline, the main steps of which are as follows:

[0011] (1) During the dam construction process, a flexible observation pipeline is buried, and the pipeline inlet and outlet are reserved in the dam observation room. After the burial is completed, the initial state measurement of the pipeline is carried out. The initial state measurement is to put the pipeline robot into the inlet of the flexible observation pipeline, start the power traction mechanism to pull the pipeline robot forward in the pipeline, and obtain the following data process line through the data acquisition and processing module of the pipeline robot:

[0012] The process curve showing how the rotation angle of the rotating rod at the head end of the main shaft of the pipeline robot changes as the distance pulled by the power traction device increases;

[0013] The process line showing how the pitch angle between the main shaft of the pipeline robot and the horizontal plane changes as the mileage pulled by the power traction device increases;

[0014] The azimuth angle of the pipeline robot's spindle projection on the horizontal plane changes as the mileage pulled by the power traction device increases (through the tunnel process line).

[0015] (2) After the dam deforms, the pipeline deformation state is measured again, using the same method as the initial pipeline state measurement.

[0016] (3) Calculate the three-dimensional displacement vector of any point in the pipeline using the data process lines obtained in steps (1) and (2). This includes the following process: obtaining the rotation angle value of the rotating rod at mileage L from the process line showing the change in rotation angle of the rotating rod at the head end of the pipeline robot's main shaft as the distance pulled by the power traction device increases, as measured in the initial state; finding the mileage L' corresponding to the rotation angle value from the process line showing the change in rotation angle of the rotating rod at the head end of the pipeline robot's main shaft as the distance pulled by the power traction device increases, as measured in the deformed state; calculating the three-dimensional coordinates of the point at mileage L in the initial state measurement curve and the three-dimensional coordinates of the point at mileage L' in the deformed state measurement curve, and subtracting the two to obtain the three-dimensional displacement vector of the point at L in the initial state of the pipeline.

[0017] Beneficial Effects: Compared with existing technologies, this invention has the following advantages: Current robotic measurement technologies for deformed pipes inside rockfill dams cannot measure the axial deformation of pipes, making it difficult to accurately determine the three-dimensional displacement vector inside the rockfill dam based on existing observation techniques. This invention can determine the three-dimensional displacement vector inside the rockfill dam, thereby obtaining more accurate deformation amounts at various points inside the rockfill dam. The measured deformation amounts include settlement and horizontal displacement, which helps to further analyze the deformation trend inside the rockfill dam and also provides more accurate data support for the dam's operational safety assessment. Attached Figure Description

[0018] Figure 1 This is the existing principle for measuring the internal settlement of rockfill dams based on pipeline measurement robots;

[0019] Figure 2 This is a schematic diagram illustrating the influence of axial deformation of the pipeline on the direction of the pipeline displacement vector.

[0020] Figure 3 This is a schematic diagram of the flexible observation pipeline structure described in this invention;

[0021] Figure 4 These are cross-sectional views of sections AA and BB;

[0022] Figure 5 This is a schematic diagram of the pipeline robot structure described in this invention;

[0023] Figure 6 This is a schematic diagram of the movement of the pipeline robot described in this invention within a flexible observation pipeline;

[0024] Figure 7This is a process line showing how the rotation angles of the three rotating rods at the head end of the main shaft of the pipeline robot described in this invention change as the mileage pulled by the power traction device increases;

[0025] Figure 8 This is a process line showing how the angle between the main shaft of the pipeline robot described in this invention and the direction of gravitational acceleration changes as the mileage pulled by the power traction device increases;

[0026] Figure 9 This is a process line showing how the azimuth angle of the pipeline robot's spindle projected onto the horizontal plane changes as the mileage pulled by the power traction device increases.

[0027] Figure 10 This is a schematic diagram of the method for calculating and determining the coordinate points of the initial curve and the measured curve as described in this invention;

[0028] Figure 11 This is a schematic diagram illustrating the calculation of the displacement vector at any point in the initial curve described in this invention. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] The measuring device for the three-dimensional displacement vector inside a rockfill dam as described in this invention includes: a flexible observation pipe with three rifling grooves arranged on the inner wall and toothed rings arranged at intervals on the outer wall; a pipe robot; a power traction mechanism, and other components forming an overall measurement system through cables, sensors, chips, and software.

[0031] like Figure 3 As shown, the inner wall of the flexible observation pipeline is equipped with rifling grooves 1. The rifling grooves 1 are made of integrally extruded HDPE pipe, and through secondary processing, three rifling grooves 1 with uniform twist angles are machined on the inner wall of the pipeline. In the cross-section, the arc angle between each pair of the three grooves is 120°. At the same time, toothed rings 2 are arranged at certain intervals on the outer wall of the pipeline. Due to the characteristics of the pipeline's own material properties, it can maintain a large radial stiffness and is not prone to radial deformation, while its axial stiffness is relatively small, allowing for more freedom in pipeline elongation and compression. Meanwhile, the toothed rings 2 arranged at intervals on the outer wall of the pipeline can reduce the possibility of relative sliding between the dam material surrounding the pipeline and the pipeline, thereby improving the synchronization between pipeline deformation and dam deformation. Figure 6 This is a schematic diagram of the pipeline robot described in this invention moving within a flexible observation pipeline. As shown in the figure, the power traction mechanism includes a drive motor and an electric winch 7; the drive motor drives the cable on the electric winch 7 to pull the pipeline robot forward, and the electric winch is equipped with sensors that can record the mileage pulled by the cable in real time.

[0032] like Figure 4 As shown, Figure 1 The cross-sectional views of sections AA and BB show that, as the rifling groove 1 has a uniform and fixed twist angle, its position rotates along the pipe axis.

[0033] like Figure 5 As shown, the pipeline robot has a main shaft 5. At each end of the main shaft 5 are three independently rotating rods 3, each capable of rotating around the main shaft 5. Each rotating rod 3 has a caster wheel 4 at its end, which smoothly engages within the rifling grooves 1 on the inner wall of the pipeline, causing the rotating rod 3 to rotate around the main shaft 5, while the main shaft 5 moves forward within the pipeline. A spring connects the caster wheel 4 to the rotating rod 3, ensuring that the caster wheel 4 remains in contact with the bottom of the rifling groove 1. During the forward movement of the pipeline robot, the traction force and the force exerted by the rotating rods on the main shaft ensure that the main shaft remains aligned with the pipeline's central axis. An electronic equipment compartment 6 is fixed to the main shaft 5, containing a data acquisition and processing module, a six-axis electronic compass, three angle sensors, and a power module. The data acquisition and processing module is responsible for acquiring and processing all sensor data. The six-axis electronic compass can record in real time the azimuth angle of the main shaft's projection onto the horizontal plane and the pitch angle between the main shaft and the direction of gravitational acceleration. Three rotation sensors can record the rotation angle of the three rotating rods at the head end of the main shaft around the main shaft in real time. The power module is responsible for powering all sensors and electronic equipment. After arranging the above four components in the electronic equipment compartment 6, it should be ensured that the center of gravity of the entire pipeline robot is below the main shaft, so that the main shaft itself does not rotate during the rotation of the rotating rods.

[0034] The method for measuring the three-dimensional displacement vector of the observed pipeline is described in detail below:

[0035] (1) Calculation and determination of coordinate points of initial curve and measured curve

[0036] The calculation and determination methods for the coordinate points of the initial curve and the measured curve are the same. Taking the initial curve as an example, the following is an introduction:

[0037] In such Figure 10 In the coordinate system shown, a finite and relatively small distance difference Δl is selected, and the curve is considered to be a straight line within this small distance. A and B are the first and last measuring points of this distance, A′ and B′ are their horizontal projections, and A″ and B″ are their projections on the vertical coordinate axis. The angles between points A and B and the direction of gravitational acceleration are θ and θ, respectively. A θ B The azimuth angles of the projections on the horizontal plane are α A α B At this point, the coordinates of point A and point B have the following relationship:

[0038]

[0039]

[0040]

[0041] In equation (1) θ A θ B Available from Figure 8 The data is obtained from the process line (e.g.) Figure 8 As shown), α A α B Available from Figure 9 The data is obtained from the process line (e.g.) Figure 9 (As shown). Taking point A as the starting point of the curve, whose coordinates are obtained from observations by the external monitoring system of the dam, the coordinates of each point on the curve with a mileage difference of Δl can be calculated segment by segment using the above formula, thereby obtaining the shape of the curve.

[0042] (2) Calculation and determination of the displacement vector of any point in the initial curve

[0043] like Figure 11 As shown, taking the calculation of the three-dimensional displacement vector at mileage L in the initial curve after deformation as an example:

[0044] First, let's start with the appendix. Figure 7 The initial curve measurement data process line yields the rotation angle values ​​ψ1, ψ2, and ψ3 of the three rotating rods at mileage L; secondly, in the attached... Figure 5 In the measurement curve data process line, find the mileages L1, L2, and L3 corresponding to ψ1, ψ2, and ψ3 in the three data process lines, and take the average value L' of the three. It can be seen that the length of the pipe section with mileage L in the initial curve becomes L' after deformation. Finally, obtain the X, Y, and Z coordinates of the point with mileage L' in the measurement curve, and subtract the X, Y, and Z coordinates of the point with mileage L in the initial curve from the X, Y, and Z coordinates of the point with mileage L in the measurement curve to obtain the three-dimensional displacement vector of the point with mileage L in the initial curve.

Claims

1. A device for measuring the three-dimensional displacement vector inside a rockfill dam, comprising a flexible observation pipe and a pipe robot, characterized in that: The inner wall of the flexible observation pipe is provided with helical rifling grooves with a certain twist angle; the pipe robot includes a main shaft, and each end of the main shaft is provided with a rotating rod that can rotate independently around the main shaft. The end of the rotating rod is provided with a universal wheel for locking the pipe robot into the rifling groove; the pipe robot also includes a data acquisition and processing module for acquiring and processing sensor data. An electronic compass is used to collect the azimuth angle of the main shaft projected onto the horizontal plane and the pitch angle between the main shaft and the direction of gravitational acceleration; an angle sensor is used to collect the angle of rotation of the rotating rod at the head end of the main shaft around the main shaft; and a power module; the structural center of gravity of the pipeline robot is located below the main shaft; the device also includes a power traction mechanism for traction of the pipeline robot to move axially in the pipeline and record the mileage in real time.

2. The measuring device for three-dimensional displacement vector inside a rockfill dam according to claim 1, characterized in that: The power traction mechanism includes a drive motor and an electric winch; the drive motor drives the pull line on the electric winch to pull the pipeline robot forward.

3. The measuring device for three-dimensional displacement vector inside a rockfill dam according to claim 1, characterized in that: The rifling grooves are three in number, and the arc angle between any two of the three grooves on the pipe cross-section is 120°. There are three rotating rods, and the included angle between each rotating rod is 120°. Each rotating rod is equipped with an angle sensor to collect the angle of rotation of each rotating rod around the main shaft.

4. The measuring device for three-dimensional displacement vector inside a rockfill dam according to claim 1, characterized in that: The flexible observation pipeline is made of HDPE pipe; the outer wall of the flexible observation pipeline is provided with toothed rings at certain intervals.

5. The measuring device for three-dimensional displacement vector inside a rockfill dam according to claim 1, characterized in that: The omnidirectional wheel is connected to the rotating rod by a spring.

6. A method for measuring the three-dimensional displacement vector inside a rockfill dam, using a measuring device for measuring the three-dimensional displacement vector inside a rockfill dam as described in claim 1, characterized in that, Includes the following steps: (1) During the dam filling process, a flexible observation pipeline is buried, and the pipeline inlet and outlet are reserved in the dam observation room. After the burial is completed, the initial state measurement of the pipeline is carried out. The initial state measurement is to put the pipeline robot into the inlet of the flexible observation pipeline, start the power traction mechanism to pull the pipeline robot forward in the pipeline, and obtain the following data process line through the data acquisition and processing module of the pipeline robot: The process curve showing how the rotation angle of the rotating rod at the head end of the main shaft of the pipeline robot changes as the distance pulled by the power traction device increases; The process line showing how the pitch angle between the main shaft of the pipeline robot and the horizontal plane changes as the mileage pulled by the power traction device increases; The process line showing how the azimuth angle of the pipeline robot's spindle projection on the horizontal plane changes as the mileage pulled by the power traction device increases; (2) After the dam deforms, the pipeline deformation state is measured again, using the same method as the initial pipeline state measurement. (3) Calculate the three-dimensional displacement vector of any point in the pipeline by using the data process line obtained in steps (1) and (2); Step (3) includes the following process: obtaining the rotation angle value ψ of the rotating rod at mileage L from the process line of the rotation angle of the rotating rod at the head end of the main shaft of the pipeline robot measured in the initial state as the mileage pulled by the power traction device increases; finding the mileage L' corresponding to the rotation angle value ψ from the process line of the rotation angle of the rotating rod at the head end of the main shaft of the pipeline robot measured in the deformed state as the mileage pulled by the power traction device increases; calculating the three-dimensional coordinates of the point at mileage L in the initial state measurement curve and the three-dimensional coordinates of the point at mileage L' in the deformed state measurement curve, and subtracting the two to obtain the three-dimensional displacement vector of the point at L in the initial state of the pipeline.

7. The method for measuring the three-dimensional displacement vector inside a rockfill dam according to claim 6, characterized in that: The pipeline robot's main shaft head end has three rotating rods, with an included angle of 120° between each rotating rod. The mileage L' is the average of the mileage corresponding to the rotation angle values ​​of the three rotating rods.

8. The method for measuring the three-dimensional displacement vector inside a rockfill dam according to claim 6, characterized in that: The formula for calculating the three-dimensional coordinates of the point at mileage L in the initial state measurement curve is as follows: In the formula, Δl is the length of the mileage unit, A and B are the first and last measuring points of the mileage unit, and x... A y A z A The three-dimensional coordinates of point A are x and x, respectively. B y B z B Let θ be the three-dimensional coordinates of point B. A θ B The angles α and B are the principal axes at points A and B respectively, and the direction of gravitational acceleration. A α B These are the azimuth angles of the projection of the principal axis onto the horizontal plane; Starting from the mileage starting point, the coordinates of each point on the process line are calculated step by step in mileage units; The method for calculating the three-dimensional coordinates of the point at mileage L' in the deformation state measurement curve is the same.

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