CN114487344B - Real-time judgment method for improved state of muck on horizontal conveyor belt of shield tunneling machine - Google Patents

Abstract

The invention discloses a real-time judgment method for the improved state of muck on a horizontal conveyor belt of a shield tunneling machine, which comprises the following steps: performing slump tests and accumulation experiments on the differently improved mucks by using the on-site mucks and the modifying agent as experimental materials to obtain the stationary state secant angle value range of the mucks in a proper improvement state; scanning the muck on a horizontal conveyor belt of the on-site shield tunneling machine through a three-dimensional laser scanner to obtain point cloud data of the muck surface, establishing a muck surface curve on the horizontal conveyor belt of the shield tunneling machine, and determining a secant angle of the muck on the horizontal conveyor belt of the shield tunneling machine; and judging the improvement state of the muck on the horizontal conveyor belt of the shield tunneling machine in real time according to the secant angle theta of the muck on the horizontal conveyor belt of the shield tunneling machine and the secant angle range of the muck in the static state under the appropriate improvement state. The invention can reduce the consumption of manpower and financial resources caused by the need of measuring the muck slump in the shield tunneling process and avoid the hysteresis for judging the improved state of the muck.

Description

A Real-time Judgment Method for the Improvement State of Muck on the Horizontal Conveyor Belt of Shield Machine

technical field

The invention belongs to the technical field of shield tunnel construction, in particular to a method for real-time judging of the improved state of dregs on a horizontal conveyor belt of a shield machine based on a three-dimensional laser scanning technology.

Background technique

During the construction of the shield tunnel, the shield muck can reach a suitable improved state, which is an important guarantee for the safe and efficient tunneling of the shield. Improper improvement of dregs may cause the following hazards: when the improved dregs are too thin and fluid, it is easy to cause gushing of the screw conveyor, which will lead to a sudden change in the pressure of the soil bin and cannot support the pressure on the face of the tunnel, resulting in a large settlement. In severe cases, it will lead to landslides in front of the shield; when the fluidity of the improved muck is poor, it is not conducive to the removal of muck, and the dregs with strong adhesion will easily stick to the cutter head and increase the wear of the cutter head.

At present, the indoor slump test is mainly used to judge the improvement status of the muck on the conveyor belt, and the improvement status can be judged by measuring the slump value. This method requires relevant personnel to remove the muck on the conveyor belt of the shield machine for slump There is a certain hysteresis in judging the muck on the conveyor belt.

Contents of the invention

The invention provides a method for real-time identification and determination of the improved state of dregs on the horizontal conveyor belt of a shield machine based on three-dimensional laser scanning technology. cost, and avoid the lag in determining the status of muck improvement.

In order to realize the above-mentioned technical purpose, the present invention adopts following technical scheme:

A method for real-time determination of the improvement state of muck on a horizontal conveyor belt of a shield machine, comprising:

Step 1. Use the on-site dregs and modifiers as experimental materials to conduct slump tests on different improved dregs, evaluate whether the improvement state of each type of muck is suitable according to the slump value, and then evaluate each suitable improvement state. The dregs are piled up for experiments, that is, the dregs are simulated to fall from the height of the shield screw machine to the conveyor belt of the shield machine, so as to obtain the value range [w _min ,w _max ] of the static state secant angle of the dregs in a suitable improved state;

Step 2: Scan the muck on the horizontal conveyor belt of the shield machine on site with a 3D laser scanner, and the scanning direction is perpendicular to the moving direction of the conveyor belt; each scan obtains the point cloud data of the muck surface, and correspondingly establishes the horizontal conveyor belt of the shield machine The surface curve of the muck, and according to the surface curve of the muck, determine the secant angle θ of the muck on the horizontal conveyor belt of the shield machine perpendicular to the moving direction of the conveyor belt;

Step 3, according to the secant angle θ of the dregs on the horizontal conveyor belt of the shield machine and the value range [w _min , w _max ] of the secant angle of the dregs at rest in a suitable improved state, judge in real time the value of the dregs on the horizontal conveyor belt of the shield machine The improved state of the muck.

Further, the judgment method of step 3 is:

If λθ∈[w _min ,w _max ], it is determined that the improved state of the muck on the horizontal conveyor belt of the shield machine is appropriate; where λ is the conversion coefficient of the static and dynamic secant angle;

If λθ>w _max , it is determined that the fluidity of the muck on the horizontal conveyor belt of the shield machine is poor, and it is necessary to adjust the water injection volume and foam injection ratio to increase the fluidity of the muck;

If λθ<w _min , it is determined that the fluidity of the muck on the horizontal conveyor belt of the shield machine is too strong or the muck is too loose, and it is necessary to adjust the water injection volume and foam injection ratio to reduce the fluidity of the muck.

Further, the conversion coefficient λ of the static and dynamic secant angle is obtained by measuring the ratio of the secant angle of the muck to the secant angle of the muck on the horizontal conveyor belt of the shield machine in the same improved state.

Further, a three-dimensional laser scanner is used to emit a linear laser, and the point cloud data on the surface of the muck is obtained by sending and receiving laser pulses, and the point cloud data is denoised by programming or existing point cloud data processing software, and then the surface of the muck is denoised. The three-dimensional model is reconstructed, and then the surface curve of the dregs perpendicular to the moving direction of the conveyor belt is obtained, and then the secant angle is determined according to the dregs surface curve.

Further, the 3D laser scanner transmits the scanned point cloud data in real time through the Ethernet or USB interface.

Further, the method for determining the secant angle is:

(1) The direction of muck accumulation on the conveyor belt is the z-axis, the direction of the conveyor belt movement is the y-axis, and the direction perpendicular to the yOz plane is the x-axis to establish a coordinate system;

(2) All the point cloud data obtained by scanning the slag surface with the 3D laser scanner along the x-axis direction are represented by the established coordinate system, and then the slag surface curve f ₁ (x, y, z) is fitted;

(3) Calculate the two points A ₁ (x ₁ ,y ₁ ,z ₁ ) and A _{2 (x 2 ,y 2 , z 2} ), and two points with the smallest z-axis value B ₁ (x ₃ , y ₃ , z ₃ ), B ₂ (x ₄ , y ₄ , z ₄ ); among them, x ₁ ≤ x ₂ , x ₃ < x ₄ ;

(4) According to the four points A ₁ , A ₂ , B ₁ , B ₂ , calculate the secant angle θ of the muck on the horizontal conveyor belt of the shield machine according to the following formula:

Compared with the prior art, the present invention has the following advantages:

1. Improve the accuracy of judging the state of muck on the horizontal conveyor belt of the shield machine. In the prior art, judging the improvement state of the dregs on the horizontal conveyor belt of the shield machine basically depends on taking soil from the site and performing a slump test. Different people have different operating procedures and modes of operation, resulting in certain errors in the results; At the same time, errors in the reading of the slump value will also have a certain impact on the result of the judgment. However, the present invention uses three-dimensional laser scanner technology to conduct non-contact measurement on the surface of the muck, reconstructs the three-dimensional model of the muck surface according to the point cloud data obtained on the surface of the muck, and judges the state of the muck through computer calculation, so that the judgment result is more accurate. precise.

2. The present invention studies the accumulation state of muck after on-site improvement, calculates the secant angle θ of the moving muck on the horizontal conveyor belt of the shield machine, and judges the state of the muck after improvement on the horizontal conveyor belt of the shield machine, so as to avoid The complexity and time-consuming nature of on-site soil mining for testing.

3. The use of 3D laser scanning technology to judge the improvement state of the dregs on the horizontal conveyor belt of the shield machine is conducive to reducing the allocation of on-site manpower, reducing the loss of on-site manpower and material resources, and is conducive to promoting shield construction to be less manned and intelligent Direction of development, and effectively ensure the personal safety of construction workers.

4. Using three-dimensional laser scanning technology to judge the improvement state of the dregs on the horizontal conveyor belt of the shield machine, process the data through the computer and make full use of the powerful computing functions of the computer to judge the improvement state of the dregs more quickly, directly for the shield driver It provides a reference for the next step of operation, and it is more reflected in the control during the construction process, which is conducive to increasing its timeliness.

Description of drawings

Fig. 1 is the flowchart of the method described in the embodiment of the present invention;

Fig. 2 is the definition diagram of the secant line angle of the muck pile body;

Fig. 3 is a contour line diagram of the cross-section of the muck on the horizontal conveyor belt of the shield machine in the coordinate system of the embodiment of the present invention.

Detailed ways

The following is a detailed description of the embodiments of the present invention. This embodiment is carried out based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes to further explain the technical solution of the present invention.

Referring to Fig. 1-Fig. 3, a real-time judgment method of the improvement state of dregs on the horizontal conveyor belt of the shield machine based on 3D laser scanning technology includes the following steps:

Step 1. Using the on-site muck and modifiers as experimental materials, conduct slump tests and accumulation experiments on dregs under different improved states to obtain the value range of the static secant angle of the dregs under the appropriate improved state [w _min ,w _max ].

Using on-site dregs and modifiers as experimental materials, conduct slump tests on dregs under different improved states, judge the improved state of muck based on the slump value and the surface of the dregs, and imitate the improved dregs to shield tunneling The distance from the screw machine to the conveyor belt of the shield machine is dropped from the height H, and the secant angle in the static state of the muck accumulation is measured, and then the range of the secant angle [w _min ,w _max ] in the static state of the dregs in a suitable improved state is obtained, Therefore, it can be used as the basis for judging the improvement state of the dregs on the horizontal conveyor belt of the shield machine.

In a specific experimental example, you can choose to set the height H to 1 meter. According to the slump and the surface characteristics of the slag, it is determined that the slump is located at [15cm, 20cm] as an appropriate improvement, and the secant angle in the static state should be at [19.6°, 28°] range.

In this step, the secant angle of the muck pile in the static state is determined in the same way as the secant angle in the subsequent step 2, that is, in the muck section perpendicular to the moving direction of the conveyor belt, take the secant angle of the muck at both ends of the same section The average value of , the value of the lower secant angle is the same.

Step 2: Scan the muck on the horizontal conveyor belt of the shield machine on site with a 3D laser scanner, and the scanning direction is perpendicular to the moving direction of the conveyor belt; each scan obtains the point cloud data of the muck surface, and correspondingly establishes the horizontal conveyor belt of the shield machine and determine the secant angle θ of the muck on the horizontal conveyor belt of the shield machine perpendicular to the moving direction of the conveyor belt according to the surface curve of the muck (the slag cross section perpendicular to the moving direction of the conveyor belt, the slag at both ends of the same section is taken The average value of the earth secant angle, the value of the lower secant angle is the same);

The three-dimensional laser scanner is used to emit linear laser, and the point cloud data on the surface of the muck is obtained by sending and receiving laser pulses, and then the real-time scanned point cloud data is sent to the computer through the Ethernet or USB interface for further processing.

After the computer receives the original point cloud data from the 3D laser scanner, because it contains various noises, the noise sources include: the 3D laser scanner shakes with the vibration of the shield machine conveyor belt, the laser line emitted by the 3D laser scanner Scattering on the water surface, the darkness of the working environment of the 3D laser scanner, and noise generated by dust, etc., so this embodiment first uses programming or existing point cloud data processing software to denoise the point cloud data;

Then, use python or other related programming software to read the processed point cloud data, and then reconstruct the 3D model of the muck surface, obtain the muck surface curve perpendicular to the moving direction of the conveyor belt, and then determine the secant line according to the muck surface curve angle. Among them, the method of determining the secant angle is:

(1) The direction of muck accumulation on the conveyor belt is the z-axis, the direction of the conveyor belt movement is the y-axis, and the direction perpendicular to the yOz plane is the x-axis to establish a coordinate system;

(2) All the point cloud data obtained by scanning the slag surface with the 3D laser scanner along the x-axis direction are represented by the established coordinate system, and then the slag surface curve f ₁ (x, y, z) is fitted;

(3) Calculate the two points A ₁ (x ₁ ,y ₁ ,z ₁ ) and A _{2 (x 2 ,y 2 , z 2} ), and two points with the smallest z-axis value B ₁ (x ₃ , y ₃ , z ₃ ), B ₂ (x ₄ , y ₄ , z ₄ ); among them, x ₁ ≤ x ₂ , x ₃ < x ₄ , if x ₁ =x ₂ then points A ₁ and A ₂ are the same point;

(4) According to the four points A ₁ , A ₂ , B ₁ , B ₂ , calculate the secant angle θ of the muck on the horizontal conveyor belt of the shield machine according to the following formula:

Step 3, according to the secant angle θ of the dregs on the horizontal conveyor belt of the shield machine and the value range [w _min , w _max ] of the secant angle of the dregs at rest in a suitable improved state, judge in real time the value of the dregs on the horizontal conveyor belt of the shield machine The improved state of the muck.

If λθ∈[w _min ,w _max ], it is judged that the improvement state of the muck on the horizontal conveyor belt of the shield machine is suitable, which is recorded as working condition 1, and the current improvement parameters of the muck can be maintained to continue excavation;

In the present invention, λ is the conversion coefficient of the static and dynamic secant angle, which is obtained by measuring the ratio of the secant angle of the muck and the secant angle of the muck on the horizontal conveyor belt of the shield machine through the muck soil in the same improved state. In this experimental example, the static and dynamic secant angle conversion coefficient λ of sandy soil is set to 2.

If λθ>w _max , it can reflect to a certain extent that the accumulation angle of muck under the current situation is relatively large, indicating that the fluidity of muck on the horizontal conveyor belt of the shield machine is poor, which is recorded as working condition 2. At this time, it is necessary to adjust the water injection volume and foam injection ratio to increase the fluidity of the muck. Through continuous monitoring and adjustment, until the secant angle θ of the muck on the horizontal conveyor belt of the shield machine satisfies λθ∈(w _min ,w _max ) Continue to dig.

If λθ<w _min , it can reflect to a certain extent that the accumulation angle of the muck under the current condition is small, indicating that the muck is too fluid or too loose in this state, which is recorded as working condition 3. At this time, it is necessary to adjust the water injection volume and foam injection ratio, reduce the fluidity of the muck to meet the requirements, and continue to monitor the adjusted and improved muck until the secant angle λθ of the muck reaches the cut angle of the muck under the appropriate improved state. In the line angle interval [w _min , w _max ], when the appropriate improved state is reached, the corresponding improved parameters are maintained to continue the excavation.

The above embodiments are preferred embodiments of the present application, and those skilled in the art can also perform various transformations or improvements on this basis, and without departing from the general concept of the application, these transformations or improvements should all belong to the present application. within the scope of the application.

Claims (4)

1. A real-time judgment method for improved state of muck on a horizontal conveyor belt of a shield tunneling machine is characterized by comprising the following steps:

step 1, utilizing on-site muck and modifying agentPerforming slump tests on the differently improved mucks as experimental materials, evaluating whether the improvement state of each muck is proper or not according to the slump value, and performing accumulation experiments on the muck in each proper improvement state, namely simulating the muck to fall from the shield screw machine to the shield machine conveyor belt so as to obtain the stationary state secant angle value range [ w ] of the muck in the proper improvement state _min ,w _max ]；

Step 2, scanning the muck on the horizontal conveyor belt of the on-site shield tunneling machine through a three-dimensional laser scanner, wherein the scanning direction is vertical to the moving direction of the conveyor belt; scanning each time to obtain point cloud data of the muck surface, correspondingly establishing a muck surface curve on a horizontal conveying belt of the shield tunneling machine, and determining a secant angle theta of the muck on the horizontal conveying belt of the shield tunneling machine in a direction perpendicular to the moving direction of the conveying belt according to the muck surface curve;

the method for determining the secant angle comprises the following steps:

(1) Establishing a coordinate system by taking the direction of the accumulation of the dregs on the conveyor belt as a z-axis, the direction of the movement of the conveyor belt as a y-axis and the direction vertical to a yOz plane as an x-axis;

(2) All point cloud data obtained by scanning the surface of the muck along the x-axis direction by using the three-dimensional laser scanner are represented by using the established coordinate system, and then a muck surface curve f is fitted ₁ (x,y,z)；

(3) Calculating the surface curve f of the dregs ₁ (x, y, z), two points A having the largest z-axis value ₁ (x ₁ ,y ₁ ,z ₁ )、A ₂ (x ₂ ,y ₂ ,z ₂ ) And two points B with minimum z-axis value ₁ (x ₃ ,y ₃ ,z ₃ )、B ₂ (x ₄ ,y ₄ ,z ₄ ) (ii) a Wherein x is ₁ ≤x ₂ ，x ₃ ＜x ₄ ；

(4) According to four points A ₁ ,A ₂ ,B ₁ ,B ₂ Calculating the secant angle theta of the muck on the horizontal conveyor belt of the shield tunneling machine according to the following formula:

step 3, according to the secant angle theta of the muck on the horizontal conveyor belt of the shield tunneling machine and the secant angle value range [ w ] of the muck in the static state under the appropriate improvement state _min ,w _max ]And judging the improved state of the muck on the horizontal conveying belt of the shield tunneling machine in real time.

2. The method according to claim 1, wherein the judging method in step 3 is:

if λ θ ∈ [ w ] _min ,w _max ]Judging that the improvement state of the muck on the horizontal conveyor belt of the shield machine is proper; wherein, the lambda is a static and dynamic secant angle transformation coefficient, and the ratio of the muck secant angle measured in an indoor experiment to the muck secant angle on the horizontal conveying belt of the shield tunneling machine is obtained by muck under the same improved state;

if λ θ > w _max If the flowability of the muck on the horizontal conveyor belt of the shield machine is poor, adjusting the water injection amount and the foam injection ratio to increase the flowability of the muck;

if λ θ < w _min If the flowability of the slag soil on the horizontal conveyor belt of the shield machine is too strong or the slag soil is too loose, the water injection amount and the foam injection ratio need to be adjusted, so that the flowability of the slag soil is reduced.

3. The method as claimed in claim 1, wherein a three-dimensional laser scanner is used to emit linear laser, the point cloud data of the surface of the dregs is obtained by sending and receiving laser pulses, the point cloud data is denoised by programming or existing point cloud data processing software, and then a three-dimensional model is reconstructed on the surface of the dregs, so as to obtain a curve of the surface of the dregs perpendicular to the moving direction of the conveyor belt, and further determine the cutting line angle according to the curve of the surface of the dregs.

4. The method of claim 1, further comprising transmitting the scanned point cloud data in real time by the three-dimensional laser scanner through an ethernet or USB interface.

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