Model test monitoring system for double-track high-speed railway roadbed vibration response characteristic research

Abstract

The invention relates to the technical field of vibration testing, in particular to a model test monitoring system for double-track high-speed railway roadbed vibration response characteristic research, which is provided with a roadbed model box, a characteristic acquisition module, a migration and deviation analysis module and a monitoring regulation and control module, the feature acquisition module is used for acquiring excitation parameters, migration deviation values and acoustic emission signals, the migration deviation analysis module is used for determining migration deviation trend values of the roadbed according to the migration deviation values of all monitoring interval sections, and the monitoring regulation and control module is used for adjusting the input amount of aeolian sand improved soil of all layers of the roadbed. According to the method, the offset characteristics of the roadbed below the track are rapidly identified in the excitation process, the input amount of each layer of aeolian sand improved soil of the roadbed is adaptively adjusted according to different offset characteristics, and the reliability of a double-track high-speed railway roadbed model test is improved.

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] As an important national infrastructure, the stability of the roadbed of high-speed railway is directly related to driving safety and service life. With the rapid development of high-speed railway 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 line passes through a large area of aeolian sand. Using aeolian sand as the filling material for the roadbed is the first choice for this project. Aeolian sand needs to be improved as a roadbed filler due to its poor grading and low cohesion. Although a large number of studies have shown that improved aeolian sand can meet the filling requirements of railway roadbed, the specific performance of improved aeolian sand after filling the railway roadbed still needs to be continuously monitored. However, the existing experimental monitoring method is difficult to dynamically quantify and analyze the deviation characteristics of the roadbed under the track, and it is difficult to set a differentiated adjustment mechanism for the input of aeolian sand improvement soil according to the deviation characteristics, which affects the reliability of improved aeolian sand as a high-speed railway roadbed filler. Therefore, improving the reliability of the double-track high-speed railway roadbed model test is a technical problem that needs to be solved urgently.

[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 foundation system, an excitation system, a sensor 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 existing caves above and below the operating tunnel on the long-term ground settlement before and after reinforcement.

[0004] The prior art still has the following problems: 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 in each layer of the roadbed according to the different offset characteristics, which affects the reliability of the double-track high-speed railway roadbed model test. Summary of the invention

[0005] 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, so as to overcome the problems that the prior art cannot quickly identify the offset characteristics of the subgrade under the track during the excitation process, cannot adaptively adjust the input amount of aeolian sand improved soil in each layer of the subgrade according to the different offset characteristics, and affects the reliability of the double-track high-speed railway subgrade model test.

[0006] To achieve the above object, the present invention provides a model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade, including: A subgrade model box for monitoring the vibration of the subgrade, with several layers of aeolian sand improved soil subgrade arranged inside, a double-track laid on the subgrade, and an exciter arranged on the double-track for applying an excitation force to the double-track; A feature acquisition module connected to the subgrade model box, including an excitation unit for acquiring the excitation parameters of the double-track, a displacement unit for acquiring the migration deviation vector of the subgrade under each track, and an acoustic emission unit for acquiring the acoustic emission signals of each layer of the subgrade; A migration deviation analysis module connected to the subgrade model box and the feature acquisition module respectively, for dividing the double-track into several monitoring interval segments, and determining the migration deviation trend quantity of the subgrade according to the migration deviation vectors of the subgrade under each track in each monitoring interval segment; A monitoring and control module connected to the subgrade model box, the feature acquisition module, and the migration deviation analysis module respectively, including an overall control unit and a hierarchical control unit. The overall control unit is used to perform overall control on the input amount of aeolian sand improved soil for each layer of the subgrade based on the determination result that the real-time migration deviation trend quantity meets the overall control condition; The hierarchical control unit is used to perform hierarchical control on the input amount of aeolian sand improved soil for each layer of the subgrade based on the determination result that the real-time migration deviation trend quantity does not meet the overall control condition.

[0007] Further, the migration deviation analysis module is used to determine the migration deviation vectors of the subgrade under the tracks in each monitoring interval segment. Among them, the migration deviation analysis module is used to obtain the center point positions of the subgrade under each track in the monitoring interval segment under the action of each excitation parameter under the sorting of the excitation parameters; The migration deviation analysis module is used to construct the migration deviation sub-vectors of the subgrade under the track. The migration deviation sub-vectors are constructed with the center point position of the subgrade under the track under the action of the previous excitation parameter among adjacent excitation parameters as the vector starting point and the center point position of the subgrade under the track under the action of the subsequent excitation parameter among adjacent excitation parameters as the vector ending point; The migration deviation analysis module is used to determine the vector sum of the migration deviation sub-vectors as the migration deviation vector of the subgrade under the track; The sorting of the excitation parameters is the sorting of the numerical values of the excitation parameters from small to large, and each monitoring interval segment includes the subgrade under two tracks.

[0008] Further, the migration deviation analysis module is used to determine the migration deviation trend quantity of the subgrade according to the determination result of the migration deviation vector of the subgrade under the track in the monitoring interval segment and the first migration tendency condition; Among them, the first migration tendency condition is that the spatial vector angle of the migration deviation vectors of the subgrade under the two tracks within the monitoring interval exceeds a preset spatial vector angle threshold.

[0009] Furthermore, the migration deviation analysis module is used to determine that the migration deviation trend quantity of the subgrade is that the variance of the straight-line distances between the characteristic points of the subgrade within the same monitoring interval under different excitation parameters exceeds a preset variance threshold based on the determination result that the migration deviation vectors of the subgrade under the track within the monitoring interval meet the first migration tendency condition.

[0010] Furthermore, the migration deviation analysis module is used to determine the characteristic points of the subgrade according to the straight-line distances between several groups of relatively distributed points on the subgrade under the track. Among them, the migration deviation analysis module is used to determine the relatively distributed points corresponding to the maximum straight-line distance as the characteristic points of the subgrade.

[0011] Furthermore, the migration deviation analysis module is used to determine that the migration deviation trend quantity of the subgrade is that the variance of the straight-line distances between the center points of the subgrade under the track within the same monitoring interval under different excitation parameters does not exceed a preset variance threshold based on the determination result that the migration deviation vectors of the subgrade under the track within the monitoring interval do not meet the first migration tendency condition.

[0012] Furthermore, the overall regulation condition is that the proportion of the number of monitoring intervals whose real-time migration deviation trend quantity meets the migration deviation trend quantity to the total number of monitoring intervals exceeds a preset proportion threshold.

[0013] Furthermore, the overall regulation unit conducts overall regulation on the input amounts of aeolian sand improved soil for each layer of the subgrade based on the determination result that the comparison situation between the real-time migration deviation trend quantity of each monitoring interval and the migration deviation trend quantity meets the overall regulation condition. Among them, the reduction amount of the input amount of aeolian sand improved soil for each layer of the subgrade is positively correlated with the vector magnitude of the subgrade migration deviation vector, and the subgrade migration deviation vector is the vector obtained by adding the migration deviation vectors of each monitoring interval.

[0014] Furthermore, the layered regulation unit conducts layered regulation on the input amounts of aeolian sand improved soil for each layer of the subgrade based on the determination result that the comparison situation between the real-time migration deviation trend quantity of each monitoring interval and the migration deviation trend quantity does not meet the overall regulation condition. Among them, the layered regulation unit is used to adjust the input amounts of aeolian sand improved soil for each layer of the subgrade in sequence according to the sorting of the signal trend characterization parameters of each layer of the subgrade, and the reduction amount of the input amount of aeolian sand improved soil for each layer of the subgrade is positively correlated with the displacement trend characterization parameter.

[0015] Further, 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 value of the acoustic emission signal of any layer of the roadbed before applying excitation to the double-track track, and the maximum amplitude value of the acoustic emission signal after applying excitation to the double-track track, and determine the absolute value of the difference between the maximum amplitude values 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.

[0016] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention is provided with 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, thereby realizing the rapid identification of the deviation characteristics of the roadbed under the track during the excitation process, and adjusting the input amount of aeolian sand improved soil in each layer of the roadbed according to the different adaptability of the deviation characteristics, thereby improving the reliability of the double-track high-speed railway roadbed model test.

[0017] 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 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 more systematic and repeatable, reducing human misjudgment, and providing a reliable analysis framework for the model test of the high-speed railway 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. Furthermore, the displacement characteristics of the roadbed under the track can be quickly identified during the vibration process. According to the different displacement 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.

[0018] 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 in a targeted manner, and improve the reliability of the double-track high-speed railway roadbed model test.

[0019] In particular, under the judgment result that the migration vector meets the first migration tendency condition, the migration trend amount is the variance of the straight-line distance between the characteristic points of the roadbed in the same monitoring section under different excitation parameters exceeding the preset variance threshold. It can be understood that the migration vector meets the first migration tendency condition, that is, the offset directions of the roadbed under the two tracks in the monitoring section are roughly different, which indicates 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 low stiffness. The relatively distributed points corresponding to the maximum value of the straight-line distance of the relatively distributed points on the roadbed under the track in the monitoring section represent the position 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 characteristic points, the changes in the roadbed under the track can be more intuitively obtained, and then, the offset characteristics of the roadbed under 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 subgrade model test can be improved.

[0020] In particular, when the judgment result that the migration vector does not meet the first migration tendency condition 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 roadbeds under the two tracks in the monitoring section are roughly the same, indicating that they bear symmetrical or unidirectional loads, the roadbeds under the two tracks are uniformly stressed, the stress distribution is symmetrical, the roadbeds under the two tracks are synchronously offset in a coordinated manner, the offset difference of the roadbeds 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, and thus, the offset characteristics of the roadbed below the track can be quickly identified during the excitation process, the migration trend can be predicted specifically, and the reliability of the double-track high-speed railway subgrade model test can be improved.

[0021] 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 synergy. If they are inconsistent, it indicates that there are defects in the local roadbed, and the order of adjustment of each layer of the roadbed needs to be determined according to the degree of defects in the roadbed. This differentiated setting can accurately match the system response mechanism, avoid local adjustment of overall problems, or blindly adjust the 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 copes with 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 vibration excitation process, and adaptively adjusts the input 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.

[0022] In particular, under the condition that the comparison between the real-time migration trend and the migration trend of each monitoring interval section meets the overall control conditions, the input of aeolian sand improved soil in each layer of the roadbed is controlled as a whole. 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, the deviations characterizing the material properties of each layer of the roadbed are consistent, and there are no 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. Furthermore, the adaptive adjustment of the input of aeolian sand improved soil in each layer of the roadbed is achieved, and the reliability of the double-track high-speed railway roadbed model test is improved.

[0023] In particular, under the condition that the comparison between the real-time migration deviation trend quantity and the migration deviation trend quantity in each monitoring interval does not meet the overall regulation conditions, the input quantity of aeolian sand improved soil for each layer of the subgrade is regulated layer by layer. It can be understood that not meeting the overall regulation conditions means that the real-time migration deviation trend quantity and the migration deviation trend quantity are relatively inconsistent, indicating that there are abnormal or damaged performances in local subgrade layers. The acoustic emission signal, i.e., the AE signal, is an elastic wave signal released inside the subgrade due to microscopic structure damage when the subgrade is affected by excitation vibration. The more severe the damage to the subgrade, the higher the energy released during the damage, the greater the amplitude of the acoustic emission signal, the greater the absolute value of the difference between the maximum amplitudes of the acoustic emission signals before and after excitation, the greater the signal trend characterization parameter, the higher-energy damage events are induced by excitation, the more severe the damage behavior, the greater the displacement trend characterization parameter, the more severe the change of the subgrade, and the greater the displacement trend characterization parameter, the more the input quantity of aeolian sand improved soil needs to be reduced to improve the stiffness. Sorting according to the signal trend characterization parameters of each layer of the subgrade, the input quantity of aeolian sand improved soil for each layer of the subgrade is adjusted in turn, and the weak layer is preferentially adjusted. Furthermore, the input quantity of aeolian sand improved soil for each layer of the subgrade is adaptively adjusted, and the reliability of the model test of the double-track high-speed railway subgrade is improved. Brief Description of the Drawings

[0024] Figure 1 is a front view of the subgrade model box according to an embodiment of the present invention; Figure 2 is a side view of the subgrade model box according to an embodiment of the present invention; Figure 3 is a functional block diagram of the model test monitoring system for studying the vibration response characteristics of the double-track high-speed railway subgrade according to an embodiment of the present invention; Figure 4 is a logic flowchart of the monitoring and regulation module for determining the regulation method of the input quantity of aeolian sand improved soil for each layer of the subgrade according to an embodiment of the present invention; In the figure: 1 - subgrade model box body; 2 - polystyrene foam board; 3 - subgrade; 4 - displacement unit; 5 - steel rail; 6 - concrete sleeper; 7 - double-track; 8 - welded rigid trolley; 9 - exciter; 10 - acoustic emission unit. Detailed Embodiments

[0025] In order to make the purpose and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the present invention.

[0026] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and do not limit the protection scope of the present invention.

[0027] It should be noted that in the description of the present invention, the terms indicating the direction or positional relationship such as "upper", "lower", "inner", "outer", etc. are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description, rather than indicating or implying that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0028] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] Please refer to Figures 1 to 3 as shown Figure 1 which is the front view of the subgrade model box of the embodiment of the present invention, Figure 2 which is the side view of the subgrade model box of the embodiment of the present invention, Figure 3 which is the functional block diagram of the model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade. A model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to the present invention includes: A subgrade model box for monitoring the vibration of the subgrade, with several layers of aeolian sand improved soil subgrade 3 arranged inside, a double-track 7 arranged on the subgrade 3, and an exciter 9 arranged on the double-track 7 for applying an excitation force to the double-track 7; Specifically, the subgrade model box body 1 is spliced and welded by an alloy material skeleton and steel plates. A polystyrene foam board 2 is embedded inside the box body as a vibration damping material, and the subgrade 3 is filled and stacked in the box; The double-track 7 is a double-track ballast track, composed of steel rails 5 and concrete sleepers 6, and the subgrade can be 3 layers; The exciter 9 can be arranged on a trolley. The trolley is a welded rigid trolley 8. The exciter 9 is connected and fixed to the trolley with bolts, so that the trolley is horizontally fixed on the steel rail 5 and can move longitudinally along the track; A signal generator can also be equipped for the exciter 9. Different frequency signals are sent through the signal generator to simulate different speeds of the high-speed train. The signal generator can output variable frequency signals, can simulate the driving process of the high-speed train accelerating or decelerating, and more vibration response characteristic data in various situations can be obtained.

[0030] Exemplarily, the corresponding relationship between the excitation frequency and the high-speed train speed is shown in Table 1 below.

[0031] Table 1 Corresponding Relationship between Excitation Frequency and High-Speed Rail Speed A feature acquisition module, which is connected to the subgrade model box, includes an excitation unit for acquiring the excitation parameters of the double-track 7, a displacement unit 4 for acquiring the migration deviation vectors of the subgrade under each track, and an acoustic emission unit 10 for acquiring the acoustic emission signals of each layer of the subgrade; 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 in the exciter 9 to acquire the excitation parameters. The excitation parameter is the excitation frequency, which will not be elaborated here.

[0032] 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 combined with a data processor. The SAA array displacement meter usually consists of multiple sensor units and can measure the displacements of multiple points simultaneously. The displacement unit 4 is arranged directly below the track and can be arranged at the middle position in the depth direction of the subgrade layer to acquire the migration deviation vectors of the subgrade under each track in each monitoring interval segment and the displacement change conditions of each point on the subgrade under each track. The displacement unit 4 is arranged directly below each track, which will not be elaborated here.

[0033] Specifically, the embodiment of the present invention does not limit the specific structure of the acoustic emission unit 10. Preferably, it can be an acoustic emission probe and an acoustic emission collector, which can be arranged at the middle position in the depth direction of each layer of the subgrade to acquire the acoustic emission signals of each layer of the subgrade, which will not be elaborated here.

[0034] A migration deviation analysis module, which is respectively connected to the subgrade model box and the feature acquisition module, is used to divide the double-track 7 into several monitoring interval segments and determine the migration deviation trend quantity of the subgrade according to the migration deviation vectors of the subgrade under each track in each monitoring interval segment; Specifically, the embodiment of the present invention does not limit the specific structure of the migration deviation analysis module. Preferably, it can be composed of logic components. The logic components can be field programmable logic components, microprocessors, processors used in computers, etc., for dividing the monitoring interval segments, determining the migration deviation vectors, and determining the migration deviation trend quantity, which will not be elaborated here.

[0035] Specifically, the interval distance between adjacent monitoring interval segments 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 those skilled in the art 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.

[0036] The monitoring and regulation module, which is respectively connected to the subgrade model box, the feature acquisition module and the migration deviation analysis module, includes an overall regulation unit and a hierarchical regulation unit. The overall regulation unit is used to overall regulate the input amount of aeolian sand improved soil for each layer of the subgrade based on the determination result that the real-time migration deviation trend quantity meets the overall regulation condition; The hierarchical regulation unit is used to hierarchically regulate the input amount of aeolian sand improved soil for each layer of the subgrade based on the determination result that the real-time migration deviation trend quantity does not meet the overall regulation condition.

[0037] Specifically, the embodiments of the present invention do not limit the specific structures of the overall regulation unit and the hierarchical regulation unit. Preferably, it can be composed of logic components. The logic components can be field programmable logic components, microprocessors, processors used in computers, etc., for overall regulating or hierarchically regulating the input amount of aeolian sand improved soil, which will not be elaborated here.

[0038] Specifically, the migration deviation analysis module is used to determine the migration deviation vector of the subgrade under the track in each monitoring section. Among them, the migration deviation analysis module is used to obtain the center point position of the subgrade under each track in the monitoring section under the action of each excitation parameter under the sorting of excitation parameters; The migration deviation analysis module is used to construct the migration deviation sub-vector of the subgrade under the track. The migration deviation sub-vector is constructed with the center point position of the subgrade under the track under the action of the previous excitation parameter among adjacent excitation parameters as the vector starting point and the center point position of the subgrade under the track under the action of the subsequent excitation parameter among adjacent excitation parameters as the vector ending point; The migration deviation analysis module is used to determine the vector sum of the migration deviation sub-vectors as the migration deviation vector of the subgrade under the track; The sorting of the excitation parameters is the sorting of the numerical values of the excitation parameters from small to large. Each monitoring section includes the subgrades under two tracks.

[0039] Specifically, in the embodiments of the present invention, the migration deviation vectors of each monitoring interval segment are obtained. It can be understood that traditional subgrade vibration monitoring often relies on empirical judgment or single-point monitoring, and it is difficult to capture the collaborative differences of the subgrade under the double-track. By quantitatively analyzing the migration deviation vectors in subsections, the complex spatial vibration response is transformed into computable vector features. Combined with the classification of migration tendencies, the test results are more systematic and repeatable, reducing human misjudgment, and providing a reliable analysis framework for the model test of high-speed rail projects. When the spatial angle between the migration deviation vectors exceeds the threshold, it indicates that there are significant differences in the displacement directions of the subgrades under the two tracks. When the spatial angle between the migration deviation vectors does not exceed the threshold, it indicates that the displacement directions of the subgrades under the two tracks are approximately the same. Through classification, local defects of the subgrade can be analyzed targeted. Furthermore, the offset characteristics of the subgrade under the track are quickly identified during the excitation process, and the input amounts of aeolian sand improved soil for each layer of the subgrade are adjusted adaptively according to different offset characteristics, improving the reliability of the double-track high-speed rail subgrade model test.

[0040] Specifically, the migration deviation analysis module is used to determine the migration deviation trend quantity of the subgrade according to the determination result of the migration deviation vector of the subgrade under the track in the monitoring interval segment and the first migration tendency condition. Wherein, the first migration tendency condition is that the spatial vector angle between the migration deviation vectors of the subgrades under the two tracks in the monitoring interval segment exceeds a preset spatial vector angle threshold.

[0041] Specifically, the preset spatial vector angle threshold can be set by those skilled in the art according to the accuracy requirements of the double-track high-speed rail 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°.

[0042] Specifically, in the embodiments of the present invention, the migration deviation trend quantity of the subgrade is determined based on the migration deviation vectors of each monitoring interval segment. It can be understood that by determining the migration deviation trend quantity for different migration deviation vectors of each monitoring interval segment respectively, the migration trend of the subgrade can be more accurately identified, thereby improving the prediction accuracy. According to different migration deviation trend quantities, monitoring resources are reasonably allocated to improve the response speed of the system. Furthermore, the offset characteristics of the subgrade under the track are quickly identified during the excitation process, and the migration deviation trend quantity is predicted targeted, improving the reliability of the double-track high-speed rail subgrade model test.

[0043] Specifically, the migration deviation analysis module is used to determine that the migration deviation trend quantity of the subgrade is that the variance of the straight-line distance between the subgrade feature points in the same monitoring interval segment under different excitation parameters exceeds a preset variance threshold based on the determination result that the migration deviation vector of the subgrade under the track in the monitoring interval segment meets the first migration tendency condition.

[0044] Specifically, the deviation analysis module is used to determine the subgrade characteristic points according to the linear distances between several groups of points relatively distributed on the subgrade under the track. Among them, the deviation analysis module is used to determine the relatively distributed points corresponding to the maximum linear distance as the subgrade characteristic points.

[0045] Specifically, several groups of points relatively distributed on the subgrade are points respectively selected at the centers in the depth direction of the subgrade under each track in the direction perpendicular to the track length direction, that is, a group of points relatively distributed on the subgrade.

[0046] Specifically, the interval distance between adjacent points on the same track is the product of the length value of the monitoring interval segment and the spacing factor. The spacing factor can be set by those skilled in the art according to 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.

[0047] Specifically, in the determination result that the deviation vector meets the first migration tendency condition in the embodiments of the present invention, the deviation trend amount is that the variance of the linear distances between the subgrade characteristic points in the same monitoring interval segment under different excitation parameters exceeds a preset variance threshold. It can be understood that the deviation vector meeting the first migration tendency condition means that the deviation directions of the subgrades under the two tracks in the monitoring interval segment are generally different, indicating that it stems from the structural incoordination response caused by asymmetric loads. The excited track transfers the load to the subgrade. Due to the uneven stiffness on both sides, the stress concentrates on the side with lower stiffness. The relatively distributed points corresponding to the maximum linear distance between the relatively distributed points on the subgrade under the track in the monitoring interval segment represent the positions with the most significant deviation changes. In the category where there is a large difference in the deviation directions of the subgrades under the two tracks in the monitoring interval segment, the spacing will be significantly enlarged or reduced. By monitoring the linear distances between the characteristic points, the change situation of the subgrade under the track can be obtained more intuitively. Furthermore, the deviation characteristics of the subgrade under the track are quickly identified during the excitation process, the deviation trend amount is predicted targeted, and the reliability of the double-track high-speed railway subgrade model test is improved.

[0048] Specifically, based on the determination result that the deviation vector of the subgrade under the track in the monitoring interval segment does not meet the first migration tendency condition, the deviation analysis module determines that the deviation trend amount of the subgrade is that the variance of the linear distances between the center points of the subgrade under the track in the same monitoring interval segment under different excitation parameters does not exceed a preset variance threshold.

[0049] Specifically, the preset variance threshold can be set by those skilled in the art 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.

[0050] Specifically, in the embodiment of the present invention, when the deviation vector does not meet the determination result of the first migration tendency condition, the deviation trend amount is the variance of the straight-line distance between the center points of the subgrade under the tracks within the same monitoring interval segment under different excitation parameters not exceeding a preset variance threshold. It can be understood that the deviation vector not meeting the first migration tendency condition means that the deviation directions of the subgrade under the two tracks within the monitoring interval segment are approximately the same, indicating that it bears symmetric or co-directional loads, the subgrade under the two tracks is uniformly stressed, the stress distribution is symmetric, the subgrade under the two tracks offsets synchronously in a cooperative manner, and the deviation difference of the subgrade under the two tracks is small. The center point of the subgrade under the track, that is, the subgrade point directly below the center point of the track, can quantify the degree of deviation amount difference through the straight-line distance between the center points of the subgrade under the track within the same monitoring interval segment under different excitation parameters. When the deviation vector does not meet the first migration tendency condition, determining the deviation trend amount as the variance of the straight-line distance between the center points of the subgrade under the track within the same monitoring interval segment under different excitation parameters not exceeding a preset variance threshold can more specifically predict the deviation trend amount. Furthermore, it realizes the rapid identification of the deviation characteristics of the subgrade under the track during the excitation process, specifically predicts the deviation trend amount, and improves the reliability of the double-track high-speed railway subgrade model test.

[0051] Specifically, the overall regulation condition is that the proportion of the number of monitoring interval segments whose real-time deviation trend amount meets the deviation trend amount to the total number of monitoring interval segments exceeds a preset proportion threshold.

[0052] Exemplarily, a specific embodiment where the real-time deviation trend amount of a monitoring interval segment meets the deviation trend amount is given here. If the determination result of monitoring interval segment A meets the first migration tendency condition, then the deviation trend amount of the subgrade of monitoring interval segment A is the variance of the straight-line distance between the subgrade characteristic points within the same monitoring interval segment under different excitation parameters exceeding a preset variance threshold. When the real-time deviation trend amount of monitoring interval segment A is the variance of the straight-line distance between the subgrade characteristic points within the same monitoring interval segment under different excitation parameters exceeding a preset variance threshold, the real-time deviation trend amount of monitoring interval segment A meets the deviation trend amount.

[0053] Specifically, the preset proportion threshold can be set by those skilled in the art according to 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.

[0054] Specifically, in the embodiments of the present invention, different regulation 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 subgrade system deviation. If they are consistent, it indicates that the performance of each layer of the subgrade as a whole deviates from the design, and the mix ratios of each layer of the subgrade need to be adjusted synchronously to maintain the interlayer coordination. If they are inconsistent, it indicates that there are defects in local layers, and the adjustment order of the subgrade layer needs to be determined according to the defect degree of each layer of the subgrade. This differential setting can accurately match the system response mechanism, avoid the blindness of adjusting the whole problem locally or the local problem globally, adaptively adjust the adjustment method of the subgrade, reduce material waste, improve the improvement efficiency, ensure the co-deformation ability of the subgrade, effectively deal with local instability, and ultimately improve the anti-vibration reliability and optimization efficiency of the subgrade. Furthermore, it realizes the rapid identification of the offset characteristics of the subgrade under the track during the excitation process, adaptively adjusts the input amount of aeolian sand improved soil for each layer of the subgrade according to different offset characteristics, and improves the reliability of the double-track high-speed railway subgrade model test.

[0055] Please refer to Figure 4 As shown, it is a logic flowchart for the monitoring and regulation module in the embodiments of the present invention to determine the regulation method for the input amount of aeolian sand improved soil for each layer of the subgrade. The overall regulation unit conducts overall regulation on the input amount of aeolian sand improved soil for each layer of the subgrade based on the determination result that the comparison situation between the real-time deviation trend quantity and the deviation trend quantity in each monitoring interval section meets the overall regulation condition. Among them, the reduction amount of the input amount of aeolian sand improved soil for each layer of the subgrade is positively correlated with the vector magnitude of the subgrade deviation vector, and the subgrade deviation vector is the vector obtained by adding the deviation vectors of each monitoring interval section.

[0056] Specifically, the vector magnitude of the subgrade deviation vector is the vector length of the subgrade deviation vector.

[0057] Specifically, the reduction amount of the input amount of aeolian sand improved soil is the product of the input amount of aeolian sand improved soil and the overall reduction coefficient. The overall reduction coefficient is the subgrade deviation factor × the vector magnitude of the subgrade deviation vector / the reference value of the vector magnitude of the subgrade deviation vector. The reference value of the vector magnitude of the subgrade deviation vector can be the average value of the vector magnitudes of the subgrade deviation vectors under the same test conditions. The subgrade deviation factor can be set by those skilled in the art according to the average value of multiple test data under the same test conditions. The value range of the subgrade deviation factor can be [0.02, 0.04] to avoid too much or too little reduction amount of the input amount of aeolian sand improved soil each time. Preferably, the subgrade deviation factor can be 0.03.

[0058] Specifically, when the comparison between the real-time migration deviation trend amount and the migration deviation trend amount in each monitoring interval section in the embodiments of the present invention meets the overall regulation conditions, the input amount of aeolian sand improved soil for each layer of the subgrade is adjusted integrally. It can be understood that meeting the overall regulation conditions means that the real-time migration deviation trend amount and the migration deviation trend amount are relatively consistent, indicating that the deviation of the material properties of each layer of the subgrade is consistent and there are no local defects. If only the input amount of aeolian sand improved soil for a certain layer is adjusted, the interlayer stiffness balance will be damaged, resulting in stress concentration. The larger the migration deviation vector of the subgrade, the lower the overall stiffness of the subgrade, and the more the input amount of aeolian sand improved soil needs to be reduced to improve the stiffness. Furthermore, the input amount of aeolian sand improved soil for each layer of the subgrade is adaptively adjusted, and the reliability of the double-track high-speed railway subgrade model test is improved.

[0059] Specifically, based on the determination result that the comparison between the real-time migration deviation trend amount and the migration deviation trend amount in each monitoring interval section does not meet the overall regulation conditions, the hierarchical regulation unit performs hierarchical regulation on the input amount of aeolian sand improved soil for each layer of the subgrade. Among them, the hierarchical regulation unit is used to sort according to the signal trend characterization parameters of each layer of the subgrade, and sequentially adjust the input amount of aeolian sand improved soil for each layer of the subgrade. The reduction amount of the input amount of aeolian sand improved soil for each layer of the subgrade is positively correlated with the displacement trend characterization parameter.

[0060] Specifically, the reduction amount of the input amount of aeolian sand improved soil is the product of the input amount of aeolian sand improved soil and the hierarchical reduction coefficient. The hierarchical 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 parameters under the same test conditions. The displacement trend factor can be set by those skilled in the art according to 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 too much or too little reduction amount of the input amount of aeolian sand improved soil each time. Preferably, the displacement trend factor can be 0.03.

[0061] Specifically, the hierarchical regulation unit is used to determine the signal trend characterization parameter and the displacement trend characterization parameter. Among them, the hierarchical regulation unit is used to obtain the maximum amplitude value of the acoustic emission signal of any layer of the subgrade before exciting the double-track rail, and the maximum amplitude value of the acoustic emission signal after exciting the double-track rail, and determine the absolute value of the difference between the maximum amplitude values as the signal trend characterization parameter; The sorting of the signal trend characterization parameters is to sort the signal trend characterization parameters of each layer of the subgrade from large to small according to the numerical values. The displacement trend characterization parameter is the variance of the straight-line distance between the subgrade characteristic points in several monitoring interval sections.

[0062] Specifically, the acquisition duration for obtaining the maximum amplitude of the acoustic emission signal before and after excitation can be set by those skilled in the art according to the average value of multiple historical data. The value range of the acquisition duration can be [5, 15], with the interval unit being s. Preferably, it can be 10 s.

[0063] Specifically, when the comparison between the real-time deviation trend quantity and the deviation trend quantity in each monitoring interval section of the embodiment of the present invention does not meet the overall regulation conditions, the input quantity of aeolian sand improved soil for each layer of the subgrade is regulated layer by layer. It can be understood that not meeting the overall regulation conditions means that the real-time deviation trend quantity and the deviation trend quantity are relatively inconsistent, indicating that there are local layer performance abnormalities or damages in the subgrade. The acoustic emission signal, i.e., the AE signal, is an elastic wave signal released inside the subgrade due to microscopic structure damage when the subgrade is affected by excitation. The more severe the damage suffered by the subgrade, the higher the energy released during the damage, the greater the amplitude of the acoustic emission signal, the greater the absolute value of the difference between the maximum amplitudes of the acoustic emission signals before and after excitation, the greater the signal trend characterization parameter, the higher-energy damage events are induced by excitation, the more severe the damage behavior, the greater the displacement trend characterization parameter, the more severe the change of the subgrade, and the greater the displacement trend characterization parameter, the more the input quantity of aeolian sand improved soil needs to be reduced to improve the stiffness. Sorting according to the signal trend characterization parameters of each layer of the subgrade, the input quantity of aeolian sand improved soil for each layer of the subgrade is adjusted in turn, and the weak layer is preferentially adjusted. Furthermore, the input quantity of aeolian sand improved soil for each layer of the subgrade is adaptively adjusted, and the reliability of the double-track high-speed railway subgrade model test is improved.

[0064] So far, the technical solution of the present invention has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0065] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope 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, Including: A subgrade model box for monitoring subgrade vibration, with several layers of aeolian sand improved soil subgrade arranged inside, a double-track laid on the subgrade, and an exciter arranged on the double-track for applying an exciting force to the double-track; A feature acquisition module connected to the subgrade model box, including an excitation unit for acquiring the excitation parameters of the double-track, a displacement unit for acquiring the migration deviation vectors of the subgrade under each track, and an acoustic emission unit for acquiring the acoustic emission signals of each layer of the subgrade; A migration deviation analysis module connected to the subgrade model box and the feature acquisition module respectively, for dividing the double-track into several monitoring interval segments, and determining the migration deviation trend quantity of the subgrade according to the migration deviation vectors of the subgrade under each track in each monitoring interval segment; A monitoring and control module connected to the subgrade model box, the feature acquisition module, and the migration deviation analysis module respectively, including an overall control unit and a hierarchical control unit. The overall control unit is used to perform overall control on the input quantity of aeolian sand improved soil for each layer of the subgrade based on the determination result that the real-time migration deviation trend quantity meets the overall control condition; The hierarchical control unit is used to perform hierarchical control on the input quantity of aeolian sand improved soil for each layer of the subgrade based on the determination result that the real-time migration deviation trend quantity does not meet the overall control condition.

2. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 1, wherein The migration deviation analysis module is used to determine the migration deviation vectors of the subgrade under the track in each monitoring interval segment. Among them, the migration deviation analysis module is used to obtain the center point positions of the subgrade under each track in the monitoring interval segment under the action of each excitation parameter under the excitation parameter sorting; The migration deviation analysis module is used to construct the migration deviation sub-vectors of the subgrade under the track. The migration deviation sub-vectors are constructed with the center point position of the subgrade under the track under the action of the previous excitation parameter among adjacent excitation parameters as the vector starting point and the center point position of the subgrade under the track under the action of the subsequent excitation parameter among adjacent excitation parameters as the vector ending point; The migration deviation analysis module is used to determine the vector sum of the migration deviation sub-vectors as the migration deviation vector of the subgrade under the track; The excitation parameter sorting is the sorting of the excitation parameter values from small to large, and each monitoring interval segment includes the subgrade under 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, characterized in that, The migration deviation analysis module is used to determine the migration deviation trend quantity of the subgrade according to the determination result of the migration deviation vector of the subgrade under the track in the monitoring interval segment and the first migration tendency condition; Among them, the first migration tendency condition is that the spatial vector angle between the migration deviation vectors of the subgrade under the two tracks in the monitoring interval segment 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, wherein The migration deviation analysis module is used to determine that the migration deviation trend quantity of the subgrade is that the variance of the straight-line distances between the subgrade characteristic points in the same monitoring interval segment under different excitation parameters exceeds a preset variance threshold based on the determination result that the migration deviation vector of the subgrade under the track in the monitoring interval segment meets the first migration tendency condition.

5. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 4, characterized in that, The migration deviation analysis module is used to determine the subgrade characteristic points according to the straight-line distances between several groups of relatively distributed points on the subgrade under the track. Among them, the migration deviation analysis module is used to determine the relatively distributed points corresponding to the maximum straight-line distance as the subgrade characteristic points.

6. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 3, wherein Based on the determination result that the deviation vector of the subgrade under the track within the monitoring interval section does not meet the first migration tendency condition, the deviation trend quantity of the subgrade is determined to be that the variance of the straight-line distance between the center points of the subgrade under the track within the same monitoring interval section under different excitation parameters does not exceed a 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, characterized in that, The overall regulation condition is that the proportion of the number of monitoring interval sections whose real-time deviation trend quantity meets the deviation trend quantity to the total number of monitoring interval sections exceeds a preset proportion 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, characterized in that Based on the determination result that the comparison situation between the real-time deviation trend quantity of each monitoring interval section and the deviation trend quantity meets the overall regulation condition, the overall regulation unit conducts an overall regulation on the input quantity of aeolian sand improved soil for each layer of the subgrade. Among them, the reduction amount of the input quantity of aeolian sand improved soil for each layer of the subgrade is positively correlated with the vector magnitude of the subgrade deviation vector, and the subgrade deviation vector is the vector obtained by adding the deviation vectors of each monitoring interval section.

9. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 7, wherein, Based on the determination result that the comparison situation between the real-time deviation trend quantity of each monitoring interval section and the deviation trend quantity does not meet the overall regulation condition, the hierarchical regulation unit conducts a hierarchical regulation on the input quantity of aeolian sand improved soil for each layer of the subgrade. Among them, the hierarchical regulation unit is used to sort according to the signal trend characterization parameters of each layer of the subgrade and adjust the input quantity of aeolian sand improved soil for each layer of the subgrade in turn. The reduction amount of the input quantity of aeolian sand improved soil for each layer of the subgrade is positively correlated with the displacement trend characterization parameter.

10. The model test monitoring system for studying the vibration response characteristics of a double-track high-speed railway subgrade according to claim 9, characterized in that, The hierarchical regulation unit is used to determine the signal trend characterization parameter and the displacement trend characterization parameter. Among them, the hierarchical regulation unit is used to obtain the maximum amplitude value of the acoustic emission signal of any layer of the subgrade before applying excitation to the double-track and the maximum amplitude value of the acoustic emission signal after applying excitation to the double-track, and determines the absolute value of the difference between the maximum amplitude values as the signal trend characterization parameter. The sorting of the signal trend characterization parameters is to sort the signal trend characterization parameters of each layer of the subgrade 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 subgrade characteristic points within several monitoring interval sections.

Images