A method for shaping the side slope of the ballast bed of a ballasted track

Abstract

The present invention provides a method for shaping the side slope of a ballast bed of a ballasted track, which relates to the technical field of side slope shaping of a ballast bed. By calculating the frictional energy consumption of the ballast in the ballast bed to determine whether the frictional energy consumption is higher than a threshold value, when the frictional energy consumption is higher than the threshold value, ballast replenishment and shaping are carried out; when the frictional energy consumption is lower than the threshold value, a side slope cross-sectional view is obtained, and the area similarity and area overflow degree between the side slope cross-sectional view and a standard side slope graph are calculated, and it is determined whether ballast collection and shaping or compaction and shaping are required according to the calculation results.

Description

Technical Field

[0001] The present invention provides a method for shaping the side slope of a ballast bed of a ballasted track, which relates to the technical field of side slope shaping of a ballast bed. Background Art

[0002] The total mileage of railways in China is long, and ballasted tracks are widely used. However, under the cyclic dynamic load of trains, the ballast will shift, sink and other phenomena, which will lead to safety hazards such as unevenness of the track surface and non-compliance with the cross-section bearing design requirements. Therefore, the railway side slope needs to be maintained regularly.

[0003] The ballast on the railway is an important material indispensable in railway construction and operation. It undertakes various functions such as support, drainage, buffering, slope adjustment and track fixation, providing a solid foundation and guarantee for railway transportation. As Figure 1 shown in the structural schematic diagram of the ballasted track (unit: mm). The ballast of the ballasted track plays an important role in bearing the train load. The ballast bed is the main factor affecting the foundation stability. The ballast (also called "ballast") laid on the ballast bed keeps the track in good elasticity and isolates the subgrade from external erosion at the same time. However, in order to keep it working continuously, it is necessary to regularly clean the sundries on the railway and maintain the shape of the ballast pile. But at present, the cleaning method completely depends on manual labor, which is time-consuming and laborious.

[0004] The ballast distribution and shaping machine for the ballast bed can complete this work efficiently. Its principle is to use advanced sensors to scan the height and slope of the ballast bed, and then adjust the working device of the machine to achieve uniform laying and shaping of the ballast. The ballast distribution and shaping machine for the ballast bed can integrate the laying of the track ballast bed, ballast shaping and track quality control, playing a crucial role in railway construction, improving the construction efficiency and optimizing the quality control, laying a foundation for the safety and reliability of railway transportation.

[0005] The development prospect of the ballast distribution and shaping method in the railway construction field is very broad. With the continuous development of automation technology, the ballast distribution and shaping method will be more intelligent and automated. The new generation of shaping method can use more accurate sensors and data analysis to make the work more simple and efficient.

[0006] The intelligent operation and maintenance of the ballast distribution and shaping method will become the further update direction. Through monitoring and data analysis, the real-time modulation, prediction and remote control of the shaping method are realized to achieve unmanned control and automatic work. When the railway side slope is maintained regularly, for different industrial and mining problems, the ballast distribution and shaping of the ballast bed requires multiple operations such as ballast replenishment, ballast collection and compaction. At present, the ballast distribution and shaping vehicle lacks a systematic automatic judgment and guidance method during the shaping process, and there is an urgent need to establish a comprehensive intelligent operation and maintenance system for ballast distribution and shaping of the ballast bed. Summary of the Invention

[0007] To solve the above technical problems, the present invention provides 1. a method for shaping the side slope of a ballast bed of a ballasted track, comprising the following steps:

[0008] Step 1, detecting the pressure generated by the train on the ballast bed, the displacement increment of the track along the pressure direction after the train passes, and the average deformation gradient of the ballast along the pressure direction when the train passes;

[0009] Step 2, calculating the frictional energy consumption of the ballast in the ballast bed and determining whether the frictional energy consumption is higher than a threshold value;

[0010] Step 3, determining whether the side slope of the ballast bed needs to be shaped:

[0011] When the frictional energy consumption is higher than the threshold value, ballast replenishment and shaping are carried out;

[0012] When the frictional energy consumption is not higher than the threshold value, obtain the cross-sectional view of the side slope, calculate the area similarity and area overflow degree between the cross-sectional view of the side slope and the standard side slope graph, and determine whether ballast collection and shaping or compaction and shaping are needed according to the calculation results.

[0013] Further, in the step 3, when the frictional energy consumption is not higher than the threshold value, the specific judgment process for carrying out ballast collection and shaping or compaction and shaping includes:

[0014] Let A1 be the number of overlapping grids between the cross-sectional view of the side slope and the standard side slope graph, and A2 be the number of grids occupied by the standard side slope graph. Calculate the area similarity I(A2, A1) between the cross-sectional view of the side slope and the standard side slope graph using the following formula:

[0015]

[0016] When the area similarity I(A2, A1) is less than the similarity threshold value, ballast collection and shaping are carried out.

[0017] Further, when the area similarity I(A2, A1) is equal to 1, calculate the area overflow degree D(A2, A1):

[0018] D(A2, A1) = A2 - (A2 ∩ A1)

[0019] Let D T be the overflow threshold value. When I(A2, A1) = 1 and 0 ≤ D(A2, A1) ≤ D T then no shaping operation is required;

[0020] When I(A2, A1) = 1 and D(A2, A1) > D T then compaction and shaping are carried out.

[0021] Further, in the step 2, the calculation method of the frictional energy consumption is as follows:

[0022] With the long-term action of train loads, calculate the cumulative frictional energy consumption ΔE of the ballast after N trains pass by. s The calculation formula is as follows:

[0023]

[0024] Where, F i is the pressure exerted by the i-th train on the ballast bed; Δμ i is the displacement increment of the track along the pressure direction after the i-th train passes by, and g i is the average deformation gradient of the ballast along the pressure direction when the i-th train passes by.

[0025] Furthermore, the average deformation gradient g of the ballast bed when the i-th train passes by i The calculation formula is:

[0026]

[0027] Where, M points are uniformly selected along the pressure direction of the ballast, and D j is the deformation value at the j-th point; D j+1 and D j-1 are the deformation values of the points one before and one after the j-th point respectively; S j+1,j-1 is the distance between the points before and after the j-th point.

[0028] Furthermore, after ballast collection and shaping or supplementary ballast shaping or compaction shaping, post-shaping inspection is carried out, including: slope gradient inspection, ballast bed top surface inspection, and ballast distribution inspection.

[0029] Furthermore, in step 1, the pressure exerted by the train on the ballast bed and the displacement increment of the track along the pressure direction after the train passes by are detected by sensors installed on the ballast bed.

[0030] Furthermore, in step 1, the slope cross-section diagram is obtained through UAV photography technology or laser scanning technology.

[0031] Compared with the prior art, the present invention has the following beneficial technical effects:

[0032] (1) By calculating the frictional energy consumption of the ballast in the ballast bed and comparing it with a threshold value, the stability of the ballast bed can be effectively judged. When the frictional energy consumption is higher than the threshold value, supplementary ballast shaping is carried out, which helps to enhance the stability and bearing capacity of the ballast bed.

[0033] (2) By monitoring the frictional energy consumption, measures can be taken before problems occur, thereby avoiding railway operation interruptions or accidents caused by unstable ballast beds.

[0034] (3) When the frictional energy consumption is lower than the threshold value, the stability of the slope can be evaluated by obtaining the slope cross-section diagram and calculating its area similarity with the standard diagram. If the similarity is lower than the threshold value, ballast cleaning and shaping are carried out, which helps to adjust the slope structure in a timely manner. Through the detailed monitoring and analysis of the ballast bed and the slope, refined management of railway infrastructure can be achieved, improving maintenance efficiency and reducing costs. Brief Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0036] Figure 1 Structural schematic diagram of a ballasted track;

[0037] Figure 2 Flow schematic diagram of the ballast slope shaping method for the ballasted track in Embodiment 1 of the present invention;

[0038] Figure 3 Schematic diagram of the slope cross-section diagram that meets the size requirements obtained according to the predetermined shooting distance of the present invention;

[0039] Figure 4 Schematic diagram of the ballast shaping vehicle of the present invention;

[0040] Figure 5 Schematic diagram of the dimensional parameters of the complete ballast cube of the present invention. Detailed Embodiments

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0042] In the attached drawings of the specific embodiments of the present invention, in order to better and more clearly describe the working principles of the components in the system and show the connection relationships of the various parts of the device, only the relative positional relationships between the components are clearly distinguished, and it does not constitute a limitation on the signal transmission direction, connection sequence, and the size, shape of each part of the structure within the component or structure.

[0043] Secondly, the "one embodiment" or "embodiment" referred to herein means a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or selectively exclusive embodiments from other embodiments.

[0044] Embodiment 1

[0045] As a granular material, under the action of load, the mutual dislocation between ballast particles will cause the sparseness of the ballast bed, which is macroscopically manifested as the settlement of the ballast bed; in addition, the particles deform, slip, roll over, etc. due to extrusion, and these processes are accompanied by changes in frictional energy dissipation.

[0046] The friction coefficient of ballast is an important parameter for the contact between ballast particles, and the friction coefficient is an index to measure the ease of relative sliding between particles. Under the long-term action of train loads, the mutual wear between ballast particles and the crushing of ballast, which causes small particles to fill the voids between particles, etc. will all lead to a decrease in the contact friction coefficient between particles, thereby affecting the mechanical properties of the ballast bed.

[0047] The method for shaping the side slope of the ballast bed of a ballasted track is a comprehensive process, including multiple links such as shaping judgment, side slope shaping, leveling and tamping, inspection and acceptance, etc. Each link needs to be carried out strictly in accordance with construction requirements and operating procedures to ensure the quality and effect of the side slope shaping of the ballast bed.

[0048] As Figure 2 shown, it is a schematic flow chart of the method for shaping the side slope of the ballast bed of a ballasted track in Embodiment 1. This method for shaping the side slope of the ballast bed includes the following steps:

[0049] In this embodiment, first, detect the pressure generated by the train on the ballast bed, the displacement increment of the track along the pressure direction after the train passes, and the average deformation gradient of the ballast along the pressure direction when the train passes.

[0050] In a preferred embodiment, the pressure generated by the train on the ballast bed and the displacement increment of the track along the pressure direction after the train passes are detected by sensors installed on the ballast bed.

[0051] In a preferred embodiment, the synthetic aperture radar interferometry (InSAR) technology can be used to detect the average deformation gradient of the ballast along the pressure direction when the train passes.

[0052] Secondly, calculate the frictional energy dissipation of the ballast bed of the ballast and determine whether the frictional energy dissipation is higher than the threshold.

[0053] When the frictional energy dissipation is higher than the threshold, perform ballast replenishment and shaping.

[0054] With the long-term action of train loads, calculate the cumulative frictional energy consumption ΔE of the ballast in the roadbed after N trains pass by. S , the frictional energy consumption ΔE S The calculation formula is as follows:

[0055]

[0056] Among them, F i is the pressure exerted on the roadbed when the i-th train passes by; Δμ i is the displacement increment of the track along the pressure direction after the i-th train passes by, and g i is the average deformation gradient of the ballast along the pressure direction when the i-th train passes by.

[0057] When the frictional energy consumption ΔE S reaches a certain threshold, that is, it can no longer bear the support of the roadbed, and ballast replenishment and shaping of the slope are required.

[0058] It should be noted that the pressure exerted by the train on the roadbed involved in the calculation formula of the frictional energy consumption ΔE S can be obtained from the self-weight and load conditions of each train. These parameters can all be obtained from the Internet database according to the departure records of each train.

[0059] The displacement increment of the track along the pressure direction after the train passes by can be obtained by the strain gauge measurement method and the displacement sensor measurement method. The strain gauge measurement method can measure the stress change of the track when the train passes by by pasting strain gauges at specific positions on the track (such as the web of the rail). Since there is a certain relationship between stress and displacement, the displacement increment of the track along the pressure direction can be indirectly deduced through stress measurement.

[0060] Among them, the displacement sensor is a device that can directly measure the displacement change of an object. In railway track monitoring, various types of displacement sensors (such as resistive, capacitive, inductive, photoelectric, etc.) can be used to measure the displacement increment of the track along the pressure direction, and the displacement change of the track along the pressure direction can be monitored in real time.

[0061] Among them, in the calculation formula of the frictional energy consumption ΔE S , the average deformation gradient is expressed as the deformation change per unit distance. Then, the expression of the average deformation gradient g i of the roadbed when the i-th train passes by is:

[0062]

[0063] Among them, M points are selected along the pressure direction of the ballast, and D j is the deformation value at the j-th point; D j+1 and D j-1The deformation values of the points immediately before and after point j respectively; S j+1,j-1 is the distance between the points before and after j.

[0064] In a preferred embodiment, M points can be uniformly selected along the pressure direction of the ballast, so S j+1,j-1 This distance is fixed, so this distance can be simply represented by S.

[0065] Determine whether the frictional energy consumption is higher than the threshold value. When the frictional energy consumption is higher than the threshold value, ballast replenishment and shaping are carried out.

[0066] In specific situations, the setting of the threshold value needs to consider safety factors. For example, in railway track maintenance, when judging whether ballast replenishment and shaping are required by calculating the frictional energy consumption of the ballast in the roadbed, the set threshold value should be able to ensure the stability of the track and the safety of train operation.

[0067] When setting the threshold value, past empirical data and historical records can also be referred to. These data can help understand the operation rules and potential risks of the system, so as to set the threshold value more accurately.

[0068] When a train travels on a railway, the roadbed will be subjected to pressure and friction from the train. These forces will cause the ballast particles to move relative to each other and rub against each other, thereby consuming energy. If this frictional energy consumption is too high, it means that the interaction between the ballast particles is too intense and may have reached the verge of breaking. When the ballast particles are at the verge of breaking, their shape and size will change, resulting in a decrease in the contact area between the particles, which will further lead to a decrease in the friction force between the particles, reducing the overall stability of the roadbed.

[0069] When the frictional energy consumption is higher than the threshold value, ballast replenishment and shaping are required. Ballast replenishment and shaping refer to replenishing ballast in the roadbed to ensure the stability of the roadbed and the geometric shape of the track, and ensure that the ballast in the railway roadbed is full.

[0070] Secondly, when the frictional energy consumption is lower than the threshold value, obtain the slope cross-section diagram, calculate the area similarity and area overflow degree between the slope cross-section diagram and the standard slope graph, and judge whether ballast collection and shaping or compaction and shaping are required based on this.

[0071] In a preferred embodiment, the slope cross-section diagram is obtained through drone photography technology or laser scanning technology.

[0072] First, obtain the standard slope graph from railway design specifications or relevant standards to ensure that the graph has clear boundaries and accurate dimensions. Create a drawing area with a grid, and the spacing of the grid should be determined according to the design accuracy. The grid should cover the entire range of the standard slope graph.

[0073] Such as Figure 3As shown, according to the predetermined shooting distance, obtain a slope cross-section diagram that meets the size requirements, align the slope cross-section diagram with a grid with a standard slope pattern, and set alignment reference points on the grid with the standard slope pattern, such as the center line of the track, the edge of the sleeper, etc., to ensure the accuracy and stability of the measurement reference points.

[0074] It should be explained that the predetermined shooting distance and meeting the size requirements mean that the proportional size of the slope cross-section diagram obtained by shooting according to the predetermined shooting distance meets the size requirements, that is, it is consistent with the proportional size of the standard slope pattern.

[0075] In this embodiment, the number of grids is used as a measure of area. This method can accurately reflect the proportional relationship of the actual area only when the grid size is small enough and evenly distributed. If the grid is large or unevenly distributed, it may lead to a deviation between the calculation result and the actual area ratio.

[0076] Specifically, the area similarity between the actually obtained slope cross-section diagram and the standard slope pattern is calculated by the following formula.

[0077] Let A1 be the number of grids overlapping between the slope cross-section diagram and the standard slope pattern, and A2 be the number of grids occupied by the standard slope pattern. The area similarity I(A2, A1) between the slope cross-section diagram and the standard slope pattern is calculated by the following formula:

[0078]

[0079] When the area similarity I(A2, A1) is less than the similarity threshold, it proves that the overlapping area between the slope cross-section diagram and the standard slope pattern is too low, or the matching degree between the slope cross-section diagram and the standard slope pattern is too low. Then, ballast cleaning and shaping are required, which means collecting the ballast scattered on the road shoulder and in the side ditch and refilling it into the ballast bed to ensure the fullness and uniformity of the ballast bed, so as to ensure the stability of the ballast bed and the flatness of the line.

[0080] When the area similarity I(A2, A1) is equal to 1, the area overflow D(A2, A1) is further calculated, and the calculation is carried out according to the following formula

[0081] D(A2, A1) = A2 - (A2 ∩ A1)

[0082] Let D T be the overflow threshold. When I(A2, A1) = 1 and 0 ≤ D(A2, A1) ≤ D T then the slope cross-section diagram and the standard slope pattern are completely matched, and no shaping operation is required at this time.

[0083] When I(A2, A1) = 1 and D(A2, A1) > D TIf so, it proves that the slope cross-section diagram not only completely covers the standard slope pattern but also exceeds the area limit, and compaction and shaping are required, which means compacting the ballast of the roadbed to ensure that the slope of the roadbed is full and uniform and meets the standards.

[0084] In a preferred embodiment, after the ballast collection and shaping or ballast replenishment and shaping or compaction and shaping according to the present invention, inspection after shaping is further required.

[0085] Inspect the slope gradient: Use measuring tools to check whether the slope gradient meets the standard requirements.

[0086] Inspect the top surface of the roadbed: Ensure that the top surface of the roadbed is flat, and the width and thickness meet the standard requirements.

[0087] Inspect the ballast distribution: Ensure that the ballast is evenly distributed without any missing or excessive accumulation.

[0088] Embodiment 2

[0089] Use a Figure 4 shown ballast shaping vehicle to adjust the shape of the ballast slope of the ballasted track according to the shaping method of Embodiment 1.

[0090] The ballast shaping vehicle has a conveyor belt type harrow. The conveyor belt type harrow is adjusted in angle by a telescopic device. After adjusting to be parallel to the standard roadbed slope (the angle with the horizontal ground is about 30°), the operation starts. The conveyor belt type harrow drives the ballast higher than the standard slope to be lifted upward, and the ballast falls during the traveling process to fill the defect lower than the standard slope height, realizing the lifting and shaping operation of the slope ballast.

[0091] In a preferred embodiment, for the ballast collection and shaping process, the ballast shaping vehicle determines the ballast collection length and angle of the ballast shaping vehicle according to the ballast collection width.

[0092] According to L as the ballast collection width, when the ballast collection harrow of the ballast shaping vehicle extends to the bottom surface of the ballast, it is perpendicular to the ballast slope, and a complete cube of ballast is taken.

[0093] As Figure 5 shown, one side length of the cross-section of this cube is the height a1 of the ballast collection harrow, and the other side length a2 is:

[0094]

[0095] where θ is the slope of the slope.

[0096] The volume V of the complete ballast cube is:

[0097] V = a1·a2·L

[0098] where L is the width of the ballast collection harrow.

[0099] In a specific application process, the standard ballast particle size is 20 - 50 mm, and the average volume V of the ballast a is approximately 20,000 mm 3 , which is applicable to the new construction, major repair, and maintenance of railways. The number of ballasts that can be lifted at one time is .

[0100] During the ballast collection and shaping process, the inclined collection hydraulic cylinder of the ballast shaper drives the ballast rake to complete the ballast slope shaping action. The horizontal collection hydraulic cylinder of the ballast shaper drives the ballast rake to complete the ballast horizontal collection action. The adjustment hydraulic cylinder of the ballast shaper drives the ballast rake to complete the working angle adjustment.

[0101] Those skilled in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non - volatile computer - readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium provided in the various embodiments of the present application can include at least one of non - volatile and volatile memories. Non - volatile memory can include read - only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high - density embedded non - volatile memory, resistive random - access memory (ReRAM), magnetoresistive random - access memory (MRAM), ferroelectric random - access memory (FRAM), phase - change memory (PCM), graphene memory, etc. Volatile memory can include random - access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random - access memory (SRAM) or dynamic random - access memory (DRAM), etc. The databases involved in the various embodiments of the present application can include at least one of relational databases and non - relational databases. Non - relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the various embodiments of the present application can be general - purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data - processing logic devices based on quantum computing, etc., without limitation.

[0102] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0103] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A method for shaping the slope of a ballast track, characterized in that: The steps include: Step 1, detecting the pressure generated by the train on the roadbed, the displacement increment of the track along the pressure direction after the train passes, and the average deformation gradient of the ballast along the pressure direction when the train passes; Step 2, calculating the friction energy consumption of the track bed and ballast, and determining whether the friction energy consumption is higher than a threshold value; The calculation method of friction energy is as follows: With the long-term effect of train load, calculate the accumulated friction energy consumption of the track bed and ballast after N trains pass through. The calculation formula is as follows: ； Among them, F i is the pressure exerted on the track bed by the i-th train; is the displacement increment of the track along the pressure direction after the i-th train passes, g i is the average deformation gradient of the ballast along the pressure direction when the i-th train passes; The average deformation gradient g of the roadbed when the i-th train passes by i The calculation formula is: ； Among them, M points are evenly selected along the pressure direction of the ballast, D j is the deformation value at point j; D j+1 and D j-1 are the deformation values ​​of a point before and after point j respectively; S j+1,j-1 is the distance between the front and rear points of point j; Step 3: Determine whether the roadbed slope needs shaping: When the friction energy consumption is higher than the threshold, ballast filling and shaping are performed; When the friction energy consumption is not higher than the threshold, obtain the slope cross-section, calculate the area similarity and area overflow between the slope cross-section and the standard slope figure, and determine whether ballast shaping or compaction shaping is needed based on the calculation results: Assume A1 is the number of grids overlapped by the slope cross-section and the standard slope figure, A2 is the number of grids occupied by the standard slope figure, and use the following formula to calculate the area similarity between the slope cross-section and the standard slope figure: : ； When the area similarity When it is less than the similarity threshold, ballast shaping is performed; When the area similarity When it is equal to 1, the area overflow is calculated : ； Assume D T is the overflow threshold, when =1 and When , no shaping operation is required; when =1 and When the surface is compacted and shaped, 2. The method for shaping the slope of a ballasted track bed according to claim 1, characterized in that: After ballast collection, ballast replenishment or compaction, a post-shaping inspection is carried out, including: slope inspection, roadbed top surface inspection, and ballast distribution inspection.

3. The method for shaping the ballast track bed slope according to claim 1, characterized in that: In step 1, the pressure exerted by the train on the track bed and the displacement increment of the track along the pressure direction after the train passes are detected by sensors installed on the track bed.

4. The method for shaping the slope of a ballasted track bed according to claim 1, characterized in that: In step 3, the slope cross-sectional view is obtained by using drone photography technology or laser scanning technology.

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