A model test monitoring system for studying vibration response characteristics of double-track high-speed railway subgrade

Abstract

The present invention relates to the field of vibration testing technology, and in particular to a model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade. The present invention provides a subgrade model box, a feature acquisition module, a migration analysis module, and a monitoring and control module. The subgrade model box is used to monitor the vibration response characteristics of the subgrade. The feature acquisition module is used to obtain excitation parameters, migration vectors, and acoustic emission signals. The migration analysis module is used to determine the migration trend of the subgrade based on the migration vectors of each monitoring interval. The monitoring and control module is used to adjust the amount of aeolian sand-improved soil added to each layer of the subgrade. The present invention achieves rapid identification of the deviation characteristics of the subgrade under the track during the excitation process, and adjusts the amount of aeolian sand-improved soil added to each layer of the subgrade according to the different adaptability of the deviation characteristics, thereby improving the reliability of the double-track high-speed railway subgrade model test.

Description

Technical Field

[0001] The present invention relates to the field of vibration testing technology, and in particular to a model test monitoring system for studying vibration response characteristics of a double-track high-speed railway subgrade. Background Art

[0002] High-speed railways are critical national infrastructure, and the stability of their roadbeds is directly related to driving safety and service life. With the rapid development of high-speed rail technology in my country, the construction of high-speed railways in sections with complex terrain has been put on the agenda. The new Baotou-Yinchuan high-speed railway project passes through a large area of aeolian sand, making aeolian sand the primary choice as a roadbed fill material for this project. Due to its poor gradation and low cohesion, aeolian sand requires modification before use as a roadbed filler. Although numerous studies have shown that modified aeolian sand can meet the requirements for railway roadbed filling, the specific performance of modified aeolian sand after use as railway roadbed fill requires continuous monitoring. However, existing experimental monitoring methods make it difficult to dynamically quantify the deflection characteristics of the roadbed beneath the tracks and to establish a differentiated adjustment mechanism for the amount of aeolian sand modification soil applied based on these deflection characteristics. This impacts the reliability of modified aeolian sand as a high-speed railway roadbed filler. Therefore, improving the reliability of double-track high-speed railway roadbed model tests is an urgent technical issue to be addressed.

[0003] For example, the Chinese patent authorization announcement number is: CN108827568B. The invention discloses a model test device for simulating long-term ground settlement in a high-density area under a complex vibration environment. The model test device for simulating long-term ground settlement in a high-density area under a complex vibration environment described in the invention includes a model box, a stratum system, a tunnel system, a high-speed railway subgrade system, an excitation system, a sensing system, a densely populated building complex on the ground, a high-speed rotation system, and a cave system. The whole process simulates the long-term ground settlement caused by the combined vibration of subways and high-speed railways in densely populated building complexes, accurately simulates the long-term ground settlement under the action of high-speed rotating centrifugal force in a complex environment, and quantitatively monitors the impact of the existing caves above and below the operating tunnel on the long-term ground settlement before and after reinforcement.

[0004] The following problems also exist in the prior art:

[0005] The existing technology cannot quickly identify the offset characteristics of the roadbed under the track during the vibration process, and cannot adaptively adjust the amount of aeolian sand improved soil input in each layer of the roadbed according to the different offset characteristics, affecting the reliability of the double-track high-speed railway roadbed model test. Summary of the Invention

[0006] To this end, the present invention provides a model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade, which is used to overcome the problems that the existing technology cannot quickly identify the offset characteristics of the roadbed under the track during the excitation process, and cannot adaptively adjust the input amount of aeolian sand improved soil in each layer of the roadbed according to the different offset characteristics, thereby affecting the reliability of the double-track high-speed railway subgrade model test.

[0007] To achieve the above-mentioned object, the present invention provides a model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade, comprising:

[0008] A roadbed model box, which is used for roadbed vibration monitoring, has a roadbed of several layers of aeolian sand-improved soil, a double-track track arranged on the roadbed, and an exciter arranged on the double-track track for applying an excitation force to the double-track track;

[0009] a feature acquisition module connected to the roadbed model box, comprising an excitation unit for acquiring excitation parameters of the double-track, a displacement unit for acquiring a deflection vector of the roadbed beneath each track, and an acoustic emission unit for acquiring acoustic emission signals of each layer of the roadbed;

[0010] a deviation analysis module, connected to the roadbed model box and the feature acquisition module, respectively, for dividing the double-track track into a plurality of monitoring sections and determining a deviation trend of the roadbed according to a deviation vector of the roadbed beneath each track in each monitoring section;

[0011] a monitoring and control module, which is respectively connected to the roadbed model box, the feature acquisition module, and the migration analysis module, and includes an overall control unit and a layered control unit, wherein the overall control unit is used to comprehensively control the amount of aeolian sand improved soil input in each layer of the roadbed based on the determination result that the real-time migration trend quantity meets the overall control conditions;

[0012] The layered control unit is used to perform layered control on the amount of aeolian sand improved soil input in each layer of the roadbed based on a determination result that the real-time migration trend quantity does not meet the overall control conditions.

[0013] Furthermore, the deviation analysis module is used to determine the deviation vector of the roadbed under the track in each monitoring section, wherein the deviation analysis module is used to obtain the center point position of the roadbed under each track in the monitoring section under the action of each excitation parameter under the order of the excitation parameters;

[0014] The deviation analysis module is used to construct a deviation sub-vector of the roadbed below the track, wherein the deviation sub-vector is constructed with the center point position of the roadbed below the track under the action of the previous excitation parameter among the adjacent excitation parameters as the vector starting point and with the center point position of the roadbed below the track under the action of the next excitation parameter among the adjacent excitation parameters as the vector end point;

[0015] The deviation analysis module is used to determine the vector sum of the deviation sub-vectors as the deviation vector of the roadbed below the track;

[0016] The excitation parameter sorting is a sorting of the excitation parameter values from small to large, and each monitoring section includes the roadbed under the two tracks.

[0017] Furthermore, the migration analysis module is used to determine the migration tendency of the roadbed according to the migration vector of the roadbed under the track in the monitoring section and the determination result of the first migration tendency condition;

[0018] The first migration tendency condition is that the spatial vector angle of the migration vectors of the roadbed under the two tracks in the monitoring section exceeds a preset spatial vector angle threshold.

[0019] Furthermore, the migration analysis module is used to determine the migration trend of the roadbed based on the judgment result that the migration vector of the roadbed under the track in the monitoring interval meets the first migration tendency condition, that the variance of the straight-line distance between the roadbed feature points in the same monitoring interval under different excitation parameters exceeds the preset variance threshold.

[0020] Furthermore, the migration analysis module is used to determine the roadbed feature point based on the straight-line distance between several groups of points relatively distributed on the roadbed below the track, wherein the migration analysis module is used to determine the relatively distributed point corresponding to the maximum straight-line distance as the roadbed feature point.

[0021] Furthermore, the migration analysis module determines that the migration trend of the roadbed is that the variance of the straight-line distance between the center points of the roadbed under the track in the same monitoring interval under different excitation parameters does not exceed a preset variance threshold based on the judgment result that the migration vector of the roadbed under the track in the monitoring interval does not meet the first migration tendency condition.

[0022] Furthermore, the overall control condition is that the ratio of the number of monitoring intervals whose real-time deviation trend quantity meets the deviation trend quantity to the total number of monitoring intervals exceeds a preset ratio threshold.

[0023] Furthermore, the overall control unit comprehensively controls the amount of aeolian sand improved soil input in each layer of the roadbed based on the judgment result that the comparison between the real-time migration trend value of each monitoring interval and the migration trend value meets the overall control conditions, wherein the reduction in the amount of aeolian sand improved soil input in each layer of the roadbed is positively correlated with the vector size of the roadbed migration vector, and the roadbed migration vector is the vector obtained by adding the migration vectors of each monitoring interval.

[0024] Furthermore, the layered control unit performs layered control on the amount of aeolian sand improved soil input in each layer of the roadbed based on the judgment result that the comparison between the real-time migration trend value of each monitoring interval and the migration trend value does not meet the overall control conditions. The layered control unit is used to sort the signal trend characterization parameters of each layer of the roadbed, and adjust the amount of aeolian sand improved soil input in each layer of the roadbed in turn. The reduction in the amount of aeolian sand improved soil input in each layer of the roadbed is positively correlated with the displacement trend characterization parameters.

[0025] Furthermore, the layered control unit is used to determine a signal trend characterization parameter and a displacement trend characterization parameter, wherein the layered control unit is used to obtain the maximum amplitude of the acoustic emission signal of any layer of the roadbed before applying vibration to the double-track track, and the maximum amplitude of the acoustic emission signal after applying vibration to the double-track track, and determine the absolute value of the difference between the maximum amplitudes as the signal trend characterization parameter;

[0026] The signal trend characterization parameter sorting is to sort the signal trend characterization parameters of each layer of the roadbed from large to small according to the numerical value, and the displacement trend characterization parameter is the variance of the straight-line distance between the roadbed feature points in several monitoring intervals.

[0027] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention sets a roadbed model box, a feature acquisition module, a migration analysis module, and a monitoring and control module. The roadbed model box is used to monitor the vibration response characteristics of the roadbed, the feature acquisition module is used to obtain excitation parameters, migration vectors, and acoustic emission signals, the migration analysis module is used to determine the migration trend of the roadbed according to the migration vectors of each monitoring interval, and the monitoring and control module is used to adjust the input amount of aeolian sand improved soil in each layer of the roadbed. Therefore, the deviation characteristics of the roadbed under the track can be quickly identified during the excitation process, and the input amount of aeolian sand improved soil in each layer of the roadbed can be adaptively adjusted according to the different deviation characteristics, thereby improving the reliability of the double-track high-speed railway roadbed model test.

[0028] In particular, the migration vector of each monitoring section is obtained. It is understandable that traditional roadbed vibration monitoring often relies on experience judgment or single-point monitoring, which makes it difficult to capture the coordination differences of the roadbed under the double-track track. By quantitatively analyzing the migration vector by segment, the complex spatial vibration response is converted into a calculable vector feature. Combined with the migration tendency classification, the test results are made more systematic and repeatable, reducing human misjudgment, and providing a reliable analysis framework for the model test of the high-speed rail project. If the spatial angle of the migration vector exceeds the threshold, it indicates that there is a significant difference in the displacement direction of the roadbed under the two tracks. If the spatial angle of the migration vector does not exceed the threshold, it indicates that the displacement direction of the roadbed under the two tracks is roughly the same. Through classification, local defects of the roadbed can be analyzed in a targeted manner, and then the displacement characteristics of the roadbed under the track can be quickly identified during the excitation process. According to the different offset characteristics, the input amount of aeolian sand improved soil in each layer of the roadbed is adaptively adjusted to improve the reliability of the double-track high-speed railway roadbed model test.

[0029] In particular, the deviation trend of the roadbed is determined based on the deviation vector of each monitoring interval. It can be understood that by determining the deviation trend for different deviation vectors of each monitoring interval, the migration trend of the roadbed can be identified more accurately, thereby improving the accuracy of the prediction. According to different deviation trend quantities, the monitoring resources can be reasonably allocated to improve the response speed of the system. Furthermore, it is possible to quickly identify the offset characteristics of the roadbed under the track during the vibration process, predict the deviation trend quantity in a targeted manner, and improve the reliability of the double-track high-speed railway roadbed model test.

[0030] In particular, when the deviation vector meets the first migration tendency condition, the deviation trend is the variance of the straight-line distances between the roadbed feature points within the same monitoring section under different excitation parameters exceeding the preset variance threshold. It can be understood that the deviation vector meets the first migration tendency condition, that is, the deviation directions of the roadbed under the two tracks in the monitoring section are roughly different, indicating that it is caused by the structural incoordination response caused by asymmetric loads. The excited track transfers the load to the roadbed. Due to the uneven stiffness on both sides, the stress is concentrated on the side with lower stiffness. The relatively distributed point corresponding to the maximum straight-line distance between the relatively distributed points on the roadbed under the track in the monitoring section represents the location of the most significant deviation change. In the category where the deviation directions of the roadbed under the two tracks in the monitoring section are significantly different, the spacing will be significantly expanded or reduced. By monitoring the straight-line distance between the feature points, the changes in the roadbed under the track can be more intuitively obtained. Therefore, it is possible to quickly identify the deviation characteristics of the roadbed under the track during the excitation process, predict the deviation trend in a targeted manner, and improve the reliability of the double-track high-speed railway roadbed model test.

[0031] In particular, under the judgment result that the migration vector does not meet the first migration tendency condition, the migration tendency amount is that the variance of the straight-line distance between the center points of the roadbed under the track in the same monitoring section under different excitation parameters does not exceed the preset variance threshold. It can be understood that the migration vector does not meet the first migration tendency condition, that is, the offset directions of the roadbed under the two tracks in the monitoring section are roughly the same, indicating that they bear symmetrical or unidirectional loads, the roadbed under the two tracks is evenly stressed, the stress distribution is symmetrical, the roadbed under the two tracks is synchronously offset in a coordinated manner, the offset difference of the roadbed under the two tracks is small, and the center of the roadbed under the track is relatively small. The point is the roadbed point directly below the center point of the track. The straight-line distance between the center points of the roadbed below the track in the same monitoring section under different excitation parameters can be used to quantify the degree of difference in its offset. When the migration vector does not meet the first migration tendency condition, the migration trend is determined as the variance of the straight-line distance between the center points of the roadbed below the track in the same monitoring section under different excitation parameters does not exceed the preset variance threshold. The migration trend can be predicted more specifically, thereby realizing the rapid identification of the offset characteristics of the roadbed below the track during the excitation process, the targeted prediction of the migration trend, and the improvement of the reliability of the double-track high-speed railway roadbed model test.

[0032] In particular, different control units are called based on the deviation trend quantity. It can be understood that whether the actual deviation trend quantity is consistent with the deviation trend quantity reflects the type of roadbed system deviation. If they are consistent, it indicates that the overall performance of each layer of the roadbed deviates from the design, and the ratio of each layer of the roadbed needs to be adjusted synchronously to maintain the inter-layer coordination. If they are inconsistent, it indicates that there are defects in the local roadbed layer, and the order of adjustment of each layer of the roadbed needs to be determined according to the degree of defects in the roadbed layer. This differentiated setting can accurately match the system response mechanism, avoid local adjustment for overall problems, or blindly adjust the global adjustment for local problems, and adaptively adjust the adjustment method of the roadbed, which can reduce material waste and improve improvement efficiency. It not only ensures the coordinated deformation ability of the roadbed, but also effectively responds to local instability, and ultimately improves the vibration resistance reliability and optimization efficiency of the roadbed. Furthermore, it realizes the rapid identification of the offset characteristics of the roadbed under the track during the excitation process, and adaptively adjusts the input amount of aeolian sand improved soil in each layer of the roadbed according to the different offset characteristics, thereby improving the reliability of the double-track high-speed railway roadbed model test.

[0033] In particular, under the condition that the comparison between the real-time migration trend and the migration trend of each monitoring section meets the overall control conditions, the input of aeolian sand improved soil in each layer of the roadbed is comprehensively controlled. It can be understood that the overall control conditions are met, that is, the real-time migration trend and the migration trend are relatively consistent, and the deviations characterizing the material properties of each layer of the roadbed are consistent, without local defects. If only the input of aeolian sand improved soil in a certain roadbed layer is adjusted, the stiffness balance between layers will be destroyed and stress concentration will be caused. The larger the roadbed migration vector, the lower the overall stiffness of the roadbed, and the more it is necessary to reduce the input of aeolian sand improved soil to increase the stiffness. In turn, the adaptive adjustment of the input of aeolian sand improved soil in each layer of the roadbed is achieved, thereby improving the reliability of the double-track high-speed railway roadbed model test.

[0034] In particular, when the comparison between the real-time deviation trend quantity and the deviation trend quantity of each monitoring section does not meet the overall control conditions, the amount of aeolian sand improved soil input in each layer of the roadbed is stratified and controlled. It can be understood that the overall control conditions are not met, that is, the real-time deviation trend quantity and the deviation trend quantity are relatively inconsistent, indicating that there is abnormal performance or damage to the local roadbed of the roadbed. The acoustic emission signal, namely the AE signal, is the elastic wave signal released by the internal microstructure damage of the roadbed when it is affected by excitation. The more serious the damage to the roadbed, the higher the energy released during the damage, the greater the amplitude of the acoustic emission signal, and the greater the excitation. The greater the absolute value of the difference between the maximum amplitudes of the acoustic emission signals before and after vibration, the larger the signal trend characterization parameter, the higher the energy damage event induced by the excitation, the more severe the damage behavior, the larger the displacement trend characterization parameter, the more severe the roadbed change, the larger the displacement trend characterization parameter, the more it is necessary to reduce the amount of aeolian sand improved soil to improve the stiffness. The roadbed layers are sorted according to the signal trend characterization parameters, and the amount of aeolian sand improved soil is adjusted for each layer of the roadbed in turn, with the weak layer being adjusted first. Thus, the adaptive adjustment of the amount of aeolian sand improved soil in each layer of the roadbed is achieved, thereby improving the reliability of the double-track high-speed railway roadbed model test. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a front schematic diagram of a roadbed model box according to an embodiment of the present invention;

[0036] Figure 2 Schematic side view of a roadbed model box according to an embodiment of the present invention;

[0037] Figure 3 This is a functional block diagram of a model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to an embodiment of the present invention;

[0038] Figure 4 This is a logic flow chart of a monitoring and control module according to an embodiment of the present invention for determining a control method for inputting an amount of aeolian sand improved soil into each layer of a roadbed;

[0039] In the figure: 1- roadbed model box; 2- polystyrene foam board; 3- roadbed; 4- displacement unit; 5- rail; 6- concrete sleeper; 7- double-track track; 8- welded rigid trolley; 9- exciter; 10- acoustic emission unit. DETAILED DESCRIPTION

[0040] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0041] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0042] It should be noted that, in the description of the present invention, terms such as "upper", "lower", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0043] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted" and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0044] See also Figures 1 to 3 As shown, Figure 1 This is a front view of a roadbed model box according to an embodiment of the present invention. Figure 2 This is a side view of a roadbed model box according to an embodiment of the present invention. Figure 3 This is a functional block diagram of a model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to an embodiment of the present invention. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to the present invention includes:

[0045] A roadbed model box, which is used for roadbed vibration monitoring, has a roadbed 3 with several layers of aeolian sand-improved soil, a double-track track 7 arranged on the roadbed 3, and an exciter 9 arranged on the double-track track 7 for applying an excitation force to the double-track track 7;

[0046] Specifically, the roadbed model box body 1 is made of an alloy frame and steel plates spliced and welded together, a polystyrene foam board 2 is embedded inside the box body as a vibration damping material, and the box body is filled with a piled roadbed 3;

[0047] The double-track track 7 is a double-track ballasted track, consisting of steel rails 5 and concrete sleepers 6, and the roadbed can be three layers;

[0048] The exciter 9 can be set on a trolley, which is a welded rigid trolley 8. The exciter 9 is fixed to the trolley with bolts so that the trolley is transversely fixed on the rail 5 and can move longitudinally along the rail;

[0049] The exciter 9 can also be equipped with a signal generator, which can emit signals of different frequencies to simulate the different speeds of the high-speed rail. The signal generator can output variable frequency signals, simulate the acceleration or deceleration process of the high-speed rail, and obtain vibration response characteristic data under more conditions.

[0050] For example, the corresponding relationship between the excitation frequency and the high-speed rail speed is shown in Table 1 below.

[0051] Table 1 Correspondence between excitation frequency and high-speed rail speed

[0052]

[0053] A feature acquisition module, connected to the roadbed model box, includes an excitation unit for acquiring excitation parameters of the double-track 7, a displacement unit 4 for acquiring a deflection vector of the roadbed beneath each track, and an acoustic emission unit 10 for acquiring acoustic emission signals of each layer of the roadbed;

[0054] Specifically, the embodiment of the present invention does not limit the specific structure of the excitation unit. Preferably, it can be a frequency meter built into the exciter 9 to obtain the excitation parameters. The excitation parameters are the excitation frequency, which will not be repeated here.

[0055] Specifically, the embodiment of the present invention does not limit the specific structure of the displacement unit 4. Preferably, it can be an SAA array displacement meter in conjunction with a data processor. The SAA array displacement meter is usually composed of multiple sensor units and can measure the displacement of multiple points at the same time. The displacement unit 4 is set directly below the track and can be set at the middle position in the depth direction of the roadbed to obtain the deviation vector of the roadbed under each track in each monitoring interval and the displacement change of each point on the roadbed under each track. The displacement unit 4 is set directly below each track, which will not be repeated here.

[0056] Specifically, the embodiment of the present invention does not limit the specific structure of the sound emission unit 10. Preferably, it can be an sound emission probe and an sound emission collector, which can be set at the middle position of each layer of the roadbed in the depth direction to obtain the sound emission signals of each layer of the roadbed. This will not be repeated.

[0057] a deviation analysis module, connected to the roadbed model box and the feature acquisition module, respectively, for dividing the double-track 7 into a plurality of monitoring sections and determining the deviation trend of the roadbed according to the deviation vector of the roadbed under each track in each monitoring section;

[0058] Specifically, the embodiment of the present invention does not limit the specific structure of the migration analysis module. Preferably, it can be constructed using logic components, which can be field programmable logic components, microprocessors, processors used in computers, etc., to divide the monitoring interval segments, determine the migration vector and determine the migration trend amount, which will not be repeated here.

[0059] Specifically, the interval distance between adjacent monitoring intervals is the product of the track length value of a single track and the interval division factor. The interval division factor can be set by technical personnel in this field according to the accuracy requirements of the double-track high-speed railway subgrade model experiment. The higher the accuracy requirement, the smaller the interval division factor. The value range of the interval division factor can be [0.01, 0.05]. Preferably, the interval division factor can be 0.02.

[0060] a monitoring and control module, which is respectively connected to the roadbed model box, the feature acquisition module, and the migration analysis module, and includes an overall control unit and a layered control unit, wherein the overall control unit is used to comprehensively control the amount of aeolian sand improved soil input in each layer of the roadbed based on the determination result that the real-time migration trend quantity meets the overall control conditions;

[0061] The layered control unit is used to perform layered control on the amount of aeolian sand improved soil input in each layer of the roadbed based on a determination result that the real-time migration trend quantity does not meet the overall control conditions.

[0062] Specifically, the embodiment of the present invention does not limit the specific structure of the overall control unit and the hierarchical control unit. Preferably, it can be composed of logic components, which can be field programmable logic components, microprocessors, processors used in computers, etc., to perform overall control or hierarchical control of the input amount of aeolian sand improved soil, which will not be repeated here.

[0063] Specifically, the deviation analysis module is used to determine the deviation vector of the roadbed under the track in each monitoring section, wherein the deviation analysis module is used to obtain the center point position of the roadbed under each track in the monitoring section under the action of each excitation parameter under the order of the excitation parameters;

[0064] The deviation analysis module is used to construct a deviation sub-vector of the roadbed below the track, wherein the deviation sub-vector is constructed with the center point position of the roadbed below the track under the action of the previous excitation parameter among the adjacent excitation parameters as the vector starting point and with the center point position of the roadbed below the track under the action of the next excitation parameter among the adjacent excitation parameters as the vector end point;

[0065] The deviation analysis module is used to determine the vector sum of the deviation sub-vectors as the deviation vector of the roadbed below the track;

[0066] The excitation parameter sorting is a sorting of the excitation parameter values from small to large, and each monitoring section includes the roadbed under the two tracks.

[0067] Specifically, the embodiment of the present invention obtains the migration vector of each monitoring interval. It is understandable that traditional roadbed vibration monitoring often relies on experience judgment or single-point monitoring, which is difficult to capture the coordination differences of the roadbed under the double-track track. By quantitatively analyzing the migration vector by segment, the complex spatial vibration response is converted into a calculable vector feature. Combined with the migration tendency classification, the test results are made more systematic and repeatable, reducing human error, and providing a reliable analysis framework for the model test of the high-speed rail project. If the spatial angle of the migration vector exceeds the threshold, it indicates that there is a significant difference in the displacement direction of the roadbed under the two tracks. If the spatial angle of the migration vector does not exceed the threshold, it indicates that the displacement direction of the roadbed under the two tracks is roughly the same. Through classification, the local defects of the roadbed can be analyzed in a targeted manner, and then, the offset characteristics of the roadbed under the track are quickly identified during the excitation process. According to the different offset characteristics, the input amount of aeolian sand improved soil in each layer of the roadbed is adaptively adjusted to improve the reliability of the double-track high-speed railway roadbed model test.

[0068] Specifically, the migration analysis module is used to determine the migration tendency of the roadbed according to the migration vector of the roadbed under the track in the monitoring section and the determination result of the first migration tendency condition;

[0069] The first migration tendency condition is that the spatial vector angle of the migration vectors of the roadbed under the two tracks in the monitoring section exceeds a preset spatial vector angle threshold.

[0070] Specifically, the preset spatial vector angle threshold can be set by technical personnel in this field based on the accuracy requirements of the double-track high-speed railway subgrade model experiment. The higher the accuracy requirement, the smaller the preset spatial vector angle threshold. The value range of the spatial vector angle threshold can be [70, 100], and the interval unit is °. Preferably, the spatial vector angle threshold can be 80°.

[0071] Specifically, the embodiment of the present invention determines the deviation trend of the roadbed based on the deviation vector of each monitoring interval. It can be understood that by determining the deviation trend for different deviation vectors of each monitoring interval, the migration trend of the roadbed can be identified more accurately, thereby improving the accuracy of the prediction. According to different deviation trend quantities, the monitoring resources can be reasonably allocated, and the response speed of the system can be improved. Furthermore, it is possible to quickly identify the offset characteristics of the roadbed under the track during the excitation process, predict the deviation trend quantity in a targeted manner, and improve the reliability of the double-track high-speed railway roadbed model test.

[0072] Specifically, the migration analysis module is used to determine the migration trend of the roadbed based on the judgment result that the migration vector of the roadbed under the track in the monitoring interval meets the first migration tendency condition, and the variance of the straight-line distance between the roadbed feature points in the same monitoring interval under different excitation parameters exceeds the preset variance threshold.

[0073] Specifically, the migration analysis module is used to determine the roadbed feature point based on the straight-line distance between several groups of points relatively distributed on the roadbed below the track, wherein the migration analysis module is used to determine the relatively distributed point corresponding to the maximum straight-line distance as the roadbed feature point.

[0074] Specifically, the relatively distributed groups of points on the roadbed are selected from a point at the center of the roadbed depth direction below each track in a direction perpendicular to the track length, that is, a relatively distributed group of points on the roadbed.

[0075] Specifically, the spacing distance between adjacent points on the same track is the product of the length of the monitoring section and the spacing factor. The spacing factor can be set by technical personnel in this field based on the accuracy requirements of the double-track high-speed railway subgrade model experiment. The higher the accuracy requirement, the smaller the spacing factor. The value range of the spacing factor can be [0.1, 0.3]. Preferably, the spacing factor can be 0.2.

[0076] Specifically, in an embodiment of the present invention, when the deviation vector satisfies the first migration tendency condition, the deviation trend value is the variance of the straight-line distance between the roadbed feature points in the same monitoring section under different excitation parameters exceeding a preset variance threshold. It can be understood that the deviation vector satisfies the first migration tendency condition, i.e., the offset directions of the roadbed under the two tracks in the monitoring section are roughly different, indicating that it is a structural incoordination response caused by asymmetric loads. The excited track transfers the load to the roadbed. Due to the uneven stiffness on both sides, the stress is concentrated on the side with lower stiffness. The relatively distributed point corresponding to the maximum straight-line distance of the relatively distributed points on the roadbed under the track in the monitoring section represents the location where the offset change is most significant. In the category where there is a large difference in the offset direction of the roadbed under the two tracks in the monitoring section, the spacing will be significantly expanded or reduced. By monitoring the straight-line distance between the feature points, the changes in the roadbed under the track can be more intuitively obtained. Furthermore, the offset characteristics of the roadbed under the track are quickly identified during the excitation process, the deviation trend value is predicted in a targeted manner, and the reliability of the double-track high-speed railway roadbed model test is improved.

[0077] Specifically, the migration analysis module determines that the migration trend of the roadbed under the track in the monitoring interval does not meet the first migration tendency condition based on the judgment result that the migration vector of the roadbed under the track in the monitoring interval does not meet the first migration tendency condition, and determines that the variance of the straight-line distance between the center points of the roadbed under the track in the same monitoring interval under different excitation parameters does not exceed the preset variance threshold.

[0078] Specifically, the preset variance threshold can be set by technical personnel in this field according to the accuracy requirements of the double-track high-speed railway subgrade model experiment. The higher the accuracy requirement, the smaller the preset variance threshold. The value range of the variance threshold can be [0.5, 1]. Preferably, the variance threshold can be 0.6.

[0079] Specifically, in the embodiment of the present invention, when the deviation vector does not meet the first migration tendency condition, the deviation trend amount is that the variance of the straight-line distance between the center points of the roadbed under the track in the same monitoring section under different excitation parameters does not exceed the preset variance threshold. It can be understood that the deviation vector does not meet the first migration tendency condition, that is, the offset directions of the roadbed under the two tracks in the monitoring section are roughly the same, indicating that they bear symmetrical or unidirectional loads, the roadbed under the two tracks is evenly stressed, the stress distribution is symmetrical, the roadbed under the two tracks is synchronously offset in a coordinated manner, the offset difference of the roadbed under the two tracks is small, and the roadbed under the tracks is relatively stable. The center point of the roadbed, that is, the roadbed point directly below the center point of the track, can be quantified by the straight-line distance between the center points of the roadbed below the track in the same monitoring interval under different excitation parameters. When the migration vector does not meet the first migration tendency condition, the migration trend amount is determined as the variance of the straight-line distance between the center points of the roadbed below the track in the same monitoring interval under different excitation parameters does not exceed the preset variance threshold. The migration trend amount can be predicted more specifically, and further, the offset characteristics of the roadbed below the track can be quickly identified during the excitation process, the migration trend amount can be predicted in a targeted manner, and the reliability of the double-track high-speed railway roadbed model test can be improved.

[0080] Specifically, the overall control condition is that the real-time deviation trend of the monitoring interval segment meets the ratio of the number of monitoring interval segments of the deviation trend amount to the total number of monitoring interval segments exceeds a preset ratio threshold.

[0081] For example, a specific embodiment is given here in which the real-time migration trend quantity of a monitoring interval section meets the migration trend quantity. The monitoring interval section A meets the judgment result of the first migration tendency condition, then the migration trend quantity of the roadbed of the monitoring interval section A is that the variance of the straight-line distance between the roadbed feature points in the same monitoring interval section under different excitation parameters exceeds the preset variance threshold. When the real-time migration trend quantity of the monitoring interval section A is that the variance of the straight-line distance between the roadbed feature points in the same monitoring interval section under different excitation parameters exceeds the preset variance threshold, the real-time migration trend quantity of the monitoring interval section A meets the migration trend quantity.

[0082] Specifically, the preset proportion threshold can be set by technical personnel in this field based on the accuracy requirements of the double-track high-speed railway subgrade model experiment. The higher the accuracy requirement, the larger the preset proportion threshold. The value range of the proportion threshold can be [0.6, 0.8]. Preferably, the proportion threshold can be 0.7.

[0083] Specifically, the embodiment of the present invention calls different control units based on the deviation trend amount. It can be understood that whether the actual deviation trend amount is consistent with the deviation trend amount reflects the type of roadbed system deviation. If they are consistent, it indicates that the overall performance of each layer of the roadbed deviates from the design, and the ratio of each layer of the roadbed needs to be adjusted synchronously to maintain the inter-layer coordination. If they are inconsistent, it indicates that there are defects in the local layer, and the order of adjusting the roadbed layer needs to be determined according to the degree of defects in each layer of the roadbed. This differentiated setting can accurately match the system response mechanism, avoid local adjustment of overall problems, or blindness of global adjustment of local problems, and adaptively adjust the adjustment method of the roadbed, which can reduce material waste and improve improvement efficiency. It not only ensures the coordinated deformation ability of the roadbed, but also effectively responds to local instability, and ultimately improves the vibration resistance reliability and optimization efficiency of the roadbed. Furthermore, it realizes the rapid identification of the offset characteristics of the roadbed under the track during the excitation process, and adaptively adjusts the input amount of aeolian sand improved soil in each layer of the roadbed according to the different offset characteristics, thereby improving the reliability of the double-track high-speed railway roadbed model test.

[0084] See also Figure 4 As shown, it is a logical flow chart of the monitoring and control module of an embodiment of the present invention determining the control method for the input amount of aeolian sand improved soil in each layer of the roadbed, and the overall control unit performs overall control on the input amount of aeolian sand improved soil in each layer of the roadbed based on the judgment result that the comparison between the real-time migration trend amount of each monitoring interval and the migration trend amount meets the overall control conditions, wherein the reduction in the input amount of aeolian sand improved soil in each layer of the roadbed is positively correlated with the vector size of the roadbed migration vector, and the roadbed migration vector is the vector obtained by adding the migration vectors of each monitoring interval.

[0085] Specifically, the vector magnitude of the roadbed deviation vector is the vector length of the roadbed deviation vector.

[0086] Specifically, the reduction in the input of aeolian sand improved soil is the product of the input of aeolian sand improved soil and the overall reduction coefficient. The overall reduction coefficient is the roadbed migration factor × the vector size of the roadbed migration vector / the vector size reference value of the roadbed migration vector. The vector size reference value of the roadbed migration vector can be the average value of the vector size of the roadbed migration vector under the same test conditions. The roadbed migration factor can be set by technical personnel in this field based on the average value of multiple test data under the same test conditions. The value range of the roadbed migration factor can be [0.02, 0.04] to avoid too much or too little reduction in the input of aeolian sand improved soil each time. Preferably, the roadbed migration factor can be 0.03.

[0087] Specifically, the embodiment of the present invention comprehensively controls the input amount of aeolian sand improved soil in each layer of the roadbed under the condition that the comparison between the real-time migration trend amount and the migration trend amount of each monitoring interval meets the overall control conditions. It can be understood that the overall control conditions are met, that is, the real-time migration trend amount and the migration trend amount are relatively consistent, and the deviations characterizing the material properties of each layer of the roadbed are consistent and there are no local defects. If only the input amount of aeolian sand improved soil in a certain layer is adjusted, the stiffness balance between layers will be destroyed and stress concentration will be caused. The larger the roadbed migration vector, the lower the overall stiffness of the roadbed, and the more it is necessary to reduce the input amount of aeolian sand improved soil to increase the stiffness. Furthermore, the adaptive adjustment of the input amount of aeolian sand improved soil in each layer of the roadbed is achieved, thereby improving the reliability of the double-track high-speed railway roadbed model test.

[0088] Specifically, the hierarchical control unit performs hierarchical control on the amount of aeolian sand improved soil in each layer of the roadbed based on the judgment result that the comparison between the real-time migration trend value of each monitoring interval and the migration trend value does not meet the overall control conditions. The hierarchical control unit is used to sort the signal trend characterization parameters of each layer of the roadbed and adjust the amount of aeolian sand improved soil in each layer of the roadbed in turn. The reduction in the amount of aeolian sand improved soil in each layer of the roadbed is positively correlated with the displacement trend characterization parameters.

[0089] Specifically, the reduction in the input of aeolian sand improved soil is the product of the input of aeolian sand improved soil and the stratification reduction coefficient. The stratification reduction coefficient is the displacement trend factor × the displacement trend characterization parameter / the displacement trend characterization reference value. The displacement trend characterization reference value can be the average value of the displacement trend characterization parameter under the same test conditions. The displacement trend factor can be set by technical personnel in this field based on the average value of multiple test data under the same test conditions. The value range of the displacement trend factor can be [0.02, 0.04] to avoid excessive or excessive reduction in the input of aeolian sand improved soil each time. Preferably, the displacement trend factor can be 0.03.

[0090] Specifically, the hierarchical control unit is used to determine a signal trend characterization parameter and a displacement trend characterization parameter, wherein the hierarchical control unit is used to obtain the maximum amplitude of the acoustic emission signal of any layer of the roadbed before applying vibration to the double-track track, and the maximum amplitude of the acoustic emission signal after applying vibration to the double-track track, and determine the absolute value of the difference between the maximum amplitudes as the signal trend characterization parameter;

[0091] The signal trend characterization parameter sorting is to sort the signal trend characterization parameters of each layer of the roadbed from large to small according to the numerical value, and the displacement trend characterization parameter is the variance of the straight-line distance between the roadbed feature points in several monitoring intervals.

[0092] Specifically, the acquisition time for obtaining the maximum amplitude of the acoustic emission signal before and after excitation can be set by a person skilled in the art based on the average value of multiple historical data. The acquisition time can be in the range of [5, 15], with the interval unit being s. Preferably, it can be 10s.

[0093] Specifically, in the embodiment of the present invention, when the comparison between the real-time deviation trend quantity and the deviation trend quantity of each monitoring interval does not meet the overall control conditions, the amount of aeolian sand improved soil input in each layer of the roadbed is stratified and regulated. It can be understood that the overall control conditions are not met, that is, the real-time deviation trend quantity and the deviation trend quantity are relatively inconsistent, indicating that there is abnormal performance or damage in the local layer of the roadbed. The acoustic emission signal, that is, the AE signal, is the elastic wave signal released by the internal microstructure damage of the roadbed when it is affected by excitation. The more serious the damage to the roadbed, the higher the energy released during the damage, and the greater the amplitude of the acoustic emission signal. The larger the absolute value of the difference between the maximum amplitudes of the acoustic emission signals before and after excitation, the larger the signal trend characterization parameter, the higher the energy damage event induced by the excitation, the more serious the damage behavior, the larger the displacement trend characterization parameter, the more serious the roadbed change, the larger the displacement trend characterization parameter, the more it is necessary to reduce the amount of aeolian sand improved soil to improve the stiffness, and the signal trend characterization parameters of each layer of the roadbed are sorted, and the amount of aeolian sand improved soil of each layer of the roadbed is adjusted in turn, with the weak layer adjusted first. Thus, the adaptive adjustment of the amount of aeolian sand improved soil of each layer of the roadbed is achieved, and the reliability of the double-track high-speed railway roadbed model test is improved.

[0094] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0095] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade, characterized in that: include: A roadbed model box, which is used for roadbed vibration monitoring, has a roadbed of several layers of aeolian sand-improved soil, a double-track track arranged on the roadbed, and an exciter arranged on the double-track track for applying an excitation force to the double-track track; a feature acquisition module connected to the roadbed model box, comprising an excitation unit for acquiring excitation parameters of the double-track, a displacement unit for acquiring a deflection vector of the roadbed beneath each track, and an acoustic emission unit for acquiring acoustic emission signals of each layer of the roadbed; a deviation analysis module, connected to the roadbed model box and the feature acquisition module, respectively, for dividing the double-track track into a plurality of monitoring sections and determining a deviation trend of the roadbed according to a deviation vector of the roadbed beneath each track in each monitoring section; a monitoring and control module, which is respectively connected to the roadbed model box, the feature acquisition module, and the migration analysis module, and includes an overall control unit and a layered control unit, wherein the overall control unit is used to comprehensively control the amount of aeolian sand improved soil input in each layer of the roadbed based on the determination result that the real-time migration trend quantity meets the overall control conditions; The layered control unit is used to perform layered control on the amount of aeolian sand improved soil input in each layer of the roadbed based on a determination result that the real-time migration trend does not meet the overall control conditions.

2. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 1 is characterized in that: The deviation analysis module is used to determine the deviation vector of the roadbed under the track in each monitoring section, wherein the deviation analysis module is used to obtain the center point position of the roadbed under each track in the monitoring section under the action of each excitation parameter under the order of the excitation parameters; The deviation analysis module is used to construct a deviation sub-vector of the roadbed below the track, wherein the deviation sub-vector is constructed with the center point position of the roadbed below the track under the action of the previous excitation parameter among the adjacent excitation parameters as the vector starting point and with the center point position of the roadbed below the track under the action of the next excitation parameter among the adjacent excitation parameters as the vector end point; The deviation analysis module is used to determine the vector sum of the deviation sub-vectors as the deviation vector of the roadbed below the track; The excitation parameter sorting is a sorting of the excitation parameter values from small to large, and each monitoring section includes the roadbed under the two tracks.

3. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 2 is characterized in that: The migration analysis module is used to determine the migration tendency of the roadbed according to the migration vector of the roadbed under the track in the monitoring section and the determination result of the first migration tendency condition; The first migration tendency condition is that the spatial vector angle of the migration vectors of the roadbed under the two tracks in the monitoring section exceeds a preset spatial vector angle threshold.

4. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 3 is characterized in that: The migration analysis module is used to determine the migration trend of the roadbed based on the judgment result that the migration vector of the roadbed under the track in the monitoring interval meets the first migration tendency condition, and to determine that the variance of the straight-line distance between the roadbed feature points in the same monitoring interval under different excitation parameters exceeds the preset variance threshold.

5. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 4 is characterized in that: The migration analysis module is used to determine the roadbed feature point based on the straight-line distance between several groups of points relatively distributed on the roadbed below the track, wherein the migration analysis module is used to determine the relatively distributed point corresponding to the maximum straight-line distance as the roadbed feature point.

6. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 3 is characterized in that: The migration analysis module determines that the migration trend of the roadbed under the track in the monitoring interval does not meet the first migration tendency condition based on the judgment result that the migration vector of the roadbed under the track in the monitoring interval does not meet the first migration tendency condition, and determines that the variance of the straight-line distance between the center points of the roadbed under the track in the same monitoring interval under different excitation parameters does not exceed the preset variance threshold.

7. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 5 or 6 is characterized in that: The overall control condition is that the real-time deviation trend of the monitoring interval segment meets the ratio of the number of monitoring interval segments of the deviation trend to the total number of monitoring interval segments exceeds a preset ratio threshold.

8. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 7 is characterized in that: The overall control unit performs overall control on the amount of aeolian sand improved soil input in each layer of the roadbed based on the judgment result that the comparison between the real-time migration trend value of each monitoring interval and the migration trend value meets the overall control conditions. The reduction in the amount of aeolian sand improved soil input in each layer of the roadbed is positively correlated with the vector size of the roadbed migration vector, and the roadbed migration vector is the vector obtained by adding the migration vectors of each monitoring interval.

9. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 7 is characterized in that: The hierarchical control unit performs hierarchical control on the amount of aeolian sand improved soil in each layer of the roadbed based on the judgment result that the comparison between the real-time migration trend value of each monitoring interval and the migration trend value does not meet the overall control conditions. The hierarchical control unit is used to sort the signal trend characterization parameters of each layer of the roadbed and adjust the amount of aeolian sand improved soil in each layer of the roadbed in turn. The reduction in the amount of aeolian sand improved soil in each layer of the roadbed is positively correlated with the displacement trend characterization parameters.

10. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 9 is characterized in that: The layered control unit is used to determine a signal trend characterization parameter and a displacement trend characterization parameter, wherein the layered control unit is used to obtain the maximum amplitude of the acoustic emission signal of any layer of the roadbed before applying vibration to the double-track track, and the maximum amplitude of the acoustic emission signal after applying vibration to the double-track track, and determine the absolute value of the difference between the maximum amplitudes as the signal trend characterization parameter; The signal trend characterization parameter sorting is to sort the signal trend characterization parameters of each layer of the roadbed from large to small according to the numerical value, and the displacement trend characterization parameter is the variance of the straight-line distance between the roadbed feature points in several monitoring intervals.

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