High-speed rail ballastless track-roadbed freezing characteristic simulation test device based on cold region meteorological conditions

Abstract

The invention belongs to the field of cold region track engineering and roadbed engineering, and particularly discloses a high-speed rail ballastless track-roadbed freezing characteristic simulation test device based on cold region meteorological conditions. Comprising a programmable high and low temperature test box used for controlling alternate change of environment temperature, a rainfall simulation device used for adjusting according to different rainfall capacities in a cold region, a solar radiation simulation device used for adjusting according to different illumination in the cold region, a ballastless track structure composed of unit block type structures, and a roadbed structure composed of three layers of structures. And the data acquisition and monitoring module is used for monitoring and acquiring deformation displacement, temperature, moisture and radiation data in real time. By means of the device, real-time monitoring of temperature, deformation, roadbed temperature, moisture, deformation and other related parameters of the ballastless track of the high-speed rail in the cold region can be achieved, the freezing depth of the roadbed and the contribution degree of each soil layer in frost heaving deformation are determined, and the influence of the ballastless track on the roadbed freezing characteristic is further analyzed.

Description

Technical Field

[0001] The present invention relates to the technical field of fault prediction and health management for cold region track engineering and subgrade engineering, and particularly relates to a simulation test device for the freezing characteristics of a ballastless track-subgrade of a high-speed railway based on cold region meteorological conditions. Background Art

[0002] In recent years, with the vigorous development of China's transportation infrastructure, the operating mileage of high-speed railways in cold regions has been increasing year by year. As the third largest permafrost country in the world, the area of seasonal frozen soil in China accounts for about 53.5%, and the area of permafrost accounts for about 21.5%. Among them, the average winter temperature of seasonal frozen soil basically remains below 0°C, and the lowest temperature in some extreme regions can reach -50°C. In recent years, with the vigorous development of China's transportation infrastructure, the total operating mileage of high-speed railways in cold regions has exceeded 8,000 km. For China's high-speed railways, ballastless tracks are widely used on lines with a designed speed of 350 km / h due to their high smoothness, good stability, and low maintenance volume. Ballastless tracks are mainly made of concrete pouring, and their structure has a large stiffness, but they have poor adaptability to the deformation of the lower foundation. In seasonal frozen soil areas, the subgrade soil experiences at least one freeze-thaw cycle every year, resulting in changes and redistribution of the temperature field, moisture field, and deformation field of the subgrade, which will cause the subgrade to frost heave and arch, and the ballastless track will thus undergo follow-up deformation, seriously threatening the safety of train operation.

[0003] Prognostics Health Management (PHM) was proposed to meet the requirements of autonomous guarantee and autonomous diagnosis, and it is an upgraded development of Condition Based Maintenance (CBM). It emphasizes state perception in asset equipment management, monitors the health status of equipment, frequently failed areas and cycles, predicts the occurrence of faults through data monitoring and analysis, and thus greatly improves the operation and maintenance efficiency.

[0004] Among them, the left and right slopes of the high-speed railway subgrade receive different amounts of solar radiation, which becomes the key factor causing uneven frost heave of the subgrade. Different orientation angles cause changes in the upper temperature of the subgrade and the amount of surface frost heave, resulting in differential deformation of the ballastless track. Therefore, the deformation control of the subgrade is the core of high-speed railway design and also the key factor to ensure the safe and stable operation of trains.

[0005] For the on-site tests of traditional ballastless track-subgrade structures, affected by various uncontrollable factors on site, it is not conducive to carrying out research on the freezing characteristics of ballastless track-subgrade structures under various working conditions; for the existing test methods for frost heave deformation of ballastless track subgrades, using full-scale track-subgrade dynamic test models, the cycle is long and the cost is high. Summary of the Invention

[0006] To solve the problems existing in the prior art, the present invention provides a simulation test device for the freezing characteristics of a ballastless track - subgrade of high - speed rail based on cold - region meteorological conditions, so as to quickly master the temperature and deformation conditions of the ballastless track of high - speed rail under different climate conditions, as well as the temperature, moisture and frost heave deformation states of the subgrade. Through this device, the freezing depth of the subgrade and the contribution degree of each soil layer in the frost heave deformation can be determined, and further the influence of the ballastless track on the freezing characteristics of the subgrade can be analyzed, thus solving the problems mentioned in the above - mentioned background technology.

[0007] To achieve the above - mentioned purpose, the present invention provides the following technical solution: A simulation test device for the freezing characteristics of a ballastless track - subgrade of high - speed rail based on cold - region meteorological conditions, the device includes a programmable high - low temperature test chamber for controlling the alternating change of environmental temperature, a rainfall simulation device for adjusting according to different rainfall amounts in cold regions, a solar radiation simulation device for adjusting according to different light intensities in cold regions, a ballastless track structure composed of unit - block structures, a subgrade structure composed of three - layer structures, and a data acquisition and monitoring module for real - time monitoring and collecting deformation displacement, temperature, moisture and radiation data;

[0008] The ballastless track structure includes a track slab layer, a self - compacting concrete layer and a base slab layer; the ballastless track structure adopts a unit - block structure, that is, 3 single - blocks of the track slab layer and 3 single - blocks of the self - compacting concrete layer are connected above the base slab layer; the track slab layer, the self - compacting concrete layer and the base slab layer are all made of cement;

[0009] The subgrade structure includes a subgrade surface layer, a subgrade bottom layer and a lower fill embankment; the subgrade surface layer uses graded crushed stone, and the subgrade bottom layer and the lower fill embankment both use Group A / B fillers; among them, the ballastless track structure is only laid on the right side of the upper surface of the subgrade structure, and is not laid on the left side of the upper surface of the subgrade structure.

[0010] Preferably, the programmable high - low temperature test chamber includes a test chamber body, a core refrigeration unit, a PLC control system, a test chamber door and an observation window arranged on the front of the test chamber body; a fan and an electric heating wire arranged at the rear end of the body; the core refrigeration unit is multiple refrigeration compressors; the PLC control system uses a Delta controller, the temperature control range is - 60°C to 80°C, the equipment operating power is 55kW, for simulating the alternating change of environmental temperature, and the overall error of the temperature control in the box is kept within 1°C to ±0.5°C.

[0011] Preferably, the rainfall simulation device includes a water storage tank, a water pump, a liquid transmission pipeline and a rain shower head located outside the test chamber; the water pump is located in the water storage tank and is connected to the power supply through a solenoid valve, for controlling the rainfall amount, rainfall speed and rainfall duration of the rainfall simulation device; the water outlet of the water pump is connected to the rain shower head below the top of the test chamber body through the liquid transmission pipeline.

[0012] Preferably, the solar radiation simulation device is a plurality of adjustable ultraviolet lamps, which are arranged symmetrically and evenly below the top of the test chamber for simulating different solar radiation angles and radiation amount changes.

[0013] Preferably, the data acquisition and monitoring module includes a radiation sensor, a frost heave displacement meter, a temperature sensor, a moisture sensor, a laser displacement sensor and a data acquisition instrument; the data acquisition instrument is connected to the radiation sensor, the frost heave displacement meter, the temperature sensor, the moisture sensor and the laser displacement sensor to monitor and collect the deformation displacement, temperature, moisture and radiation data of the ballastless track - subgrade in real time.

[0014] Preferably, the temperature sensor is arranged inside the ballastless track structure and the subgrade structure for collecting the temperature change inside the ballastless track and the subgrade. The specific arrangement includes: 1) The temperature sensors are arranged along the center of the cross-section of the subgrade structure, the lower part of the center of the base slab layer of the ballastless track and the symmetric position on its left side, starting from 0.02 m below the top surface of the subgrade structure, with a vertical spacing of 0.1 m from top to bottom, a total of 15, to monitor the horizontal and vertical ground temperature change laws of the subgrade structure during the freezing process; 2) The temperature sensors are arranged vertically along the center of the ballastless track, a total of 3; among which 2 are respectively placed on the upper surface and the middle part of the track slab layer, and 1 is placed in the middle part of the base slab layer to monitor the temperature change laws at different vertical positions of the ballastless track structure during the freezing process.

[0015] Preferably, the moisture sensor is arranged inside the subgrade structure for collecting the moisture change inside the subgrade; the moisture sensors are arranged along the center of the cross-section of the subgrade structure, the lower part of the center of the base slab layer of the ballastless track and the symmetric position on its left side, starting from 0.04 m below the top surface of the subgrade structure, with a vertical spacing of 0.1 m from top to bottom, a total of 15, to monitor the horizontal and vertical moisture change laws of the subgrade structure during the freezing process.

[0016] Preferably, the frost heave displacement meter is arranged inside the subgrade structure for collecting the frost heave deformation amounts at different depths inside the subgrade; the frost heave displacement meters are arranged at the center of the subgrade and the center of the left side of the subgrade, a total of 2, to monitor the frost heave deformation change laws of the soil at different depths of the subgrade during the freezing process.

[0017] Preferably, the laser displacement sensors are arranged on the laser displacement sensor clamping devices on the left and right sides inside the test chamber, a total of 3. The angles and height positions of the laser displacement sensors can be freely adjusted through the laser displacement sensor clamping devices to facilitate monitoring the frost heave deformation laws of the left and right side slopes of the ballastless track and the subgrade.

[0018] Preferably, three radiation sensors are arranged at the center of the upper surface of the subgrade structure and on the surface of the left and right side slopes of the subgrade, for monitoring the variation law of the radiation amount received by the subgrade surface.

[0019] The beneficial effects of the present invention are as follows: By using the built-scale high-speed railway ballastless track-subgrade model and conducting tests in a programmable high and low temperature test chamber that provides a stable temperature and humidity working environment, the present invention proposes a simulation test device for the freezing characteristics of high-speed railway ballastless track-subgrade based on cold region meteorological conditions. By changing environmental factors such as temperature, rainfall, and radiation, the development and variation laws of the temperature, deformation of the ballastless track structure, and the temperature, moisture, and frost heave deformation of the subgrade structure are revealed, the freezing depth of the subgrade and the contribution degree of frost heave deformation of each soil layer are clarified, and the influence of the ballastless track on the freezing characteristics of the subgrade can also be further analyzed. Brief Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the overall structure of the simulation test device for the freezing characteristics of high-speed railway ballastless track-subgrade based on cold region meteorological conditions in the embodiment of the present invention;

[0021] Figure 2 It is a front view of the simulation test device in the embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the position of the ballastless track-subgrade data acquisition and monitoring section in the embodiment of the present invention;

[0023] Figure 4 It is a schematic diagram of the setting of each sensor in the ballastless track-subgrade structure in the embodiment of the present invention;

[0024] Figure 5 It is Figure 4 a partial enlarged schematic diagram of part A in

[0025] Figure 6 It is Figure 4 a partial enlarged schematic diagram of part B in

[0026] In the figure, 1 - test chamber body; 2 - observation window; 3 - PLC control system; 4 - test chamber door; 5 - rain shower nozzle; 6 - surface layer of subgrade bed; 7 - bottom layer of subgrade bed; 8 - lower fill embankment; 9 - adjustable ultraviolet lamp; 10 - liquid transmission pipeline; 11 - ballastless track structure; 12 - refrigeration compressor; 13 - water storage tank; 14 - water outlet; 15 - track slab layer; 16 - self-compacting concrete layer; 17 - base slab layer; 18 - radiation sensor; 19 - frost heave displacement gauge; 20 - temperature sensor; 21 - moisture sensor; 22 - laser displacement sensor; 23 - laser displacement sensor clamping device. Detailed Embodiments

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] It should be noted that, without conflict, the implementation manners and features in the embodiments of the present invention can be combined with each other. It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "install", "connect", "couple" 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 of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0031] The present invention uses a small indoor model to approximately replace large-scale tests. The small-scale test has the advantages of low cost, saving manpower and material resources, and shortening the test cycle. Therefore, through indoor processing and assembly, a simulation test device for the freezing characteristics of a ballastless track - subgrade of high-speed railway based on cold region meteorological conditions is proposed to quickly master the temperature and deformation of the ballastless track of high-speed railway and the temperature, moisture, and frost heave deformation states of the subgrade, clarify the freezing depth of the subgrade and the contribution degree of frost heave deformation of each soil layer, and can also further analyze the influence of the ballastless track on the freezing characteristics of the subgrade.

[0032] Please refer to Figures 1-6, the present invention provides a technical solution: a simulation test device for the freezing characteristics of ballastless track - subgrade based on cold region meteorological conditions, which can simultaneously measure various data related to freeze - thaw of the ballastless track and subgrade and explore the influence of the ballastless track on the freezing characteristics of the subgrade. The device includes a programmable high - low temperature test chamber for controlling the alternating change of environmental temperature, a rainfall simulation device for adjusting according to different rainfall amounts in cold regions, a solar radiation simulation device for adjusting according to different light conditions in cold regions, a ballastless track structure composed of unit block structures, a subgrade structure composed of three - layer structures, and a data acquisition and monitoring module for real - time monitoring and collecting deformation displacement, temperature, moisture, and radiation data.

[0033] The ballastless track - subgrade model of the present invention includes a ballastless track structure and a subgrade structure scaled down according to theory, as Figure 3 shown; the ballastless track structure 11 includes a track slab layer 15, a self - compacting concrete layer 16, and a base slab layer 17, which are, from top to bottom, the track slab layer 15, the self - compacting concrete layer 16, and the base slab layer 17. The ballastless track structure 11 adopts a unit block structure, that is, 3 single blocks of the track slab layer 15 and 3 single blocks of the self - compacting concrete layer 16 are connected above the base slab layer 17; the track slab layer 15, the self - compacting concrete layer 16, and the base slab layer 17 are all made of cement. The size of a single track slab is 0.56m×0.25m×0.021m (length×width×height), the size of a single self - compacting concrete block is 0.56m×0.25m×0.01m (length×width×height), and the size of a single base slab is 1.70m×0.31m×0.03m (length×width×height). A total of 1 ballastless track model is laid on the right side of the upper surface of the subgrade.

[0034] Furthermore, the subgrade structure, from top to bottom, is the subgrade surface layer 6, the subgrade base layer 7, and the lower fill embankment 8; among them, the length of the subgrade is 2.5m, the width of the upper surface is 1.34m, the height is 0.5m, and the slope foot of the slope is 1:1.5. The subgrade material is divided into 3 layers from top to bottom: the thickness of the subgrade surface layer 6 is 0.04m, the thickness of the subgrade base layer 7 is 0.23m, and the thickness of the lower fill embankment layer 8 is 0.23m.

[0035] The subgrade surface layer 6 uses graded crushed stone, and the subgrade base layer 7 and the lower fill embankment 8 both use Group A / B fillers; among them, only the ballastless track structure is laid on the right side of the upper surface of the subgrade structure, and no ballastless track structure is laid on the left side of the upper surface of the subgrade structure.

[0036] Furthermore, as Figure 1As shown in the figure, the programmable high and low temperature test chamber includes a test chamber body 1, a core refrigeration unit, a PLC control system 3, a test chamber door 4 and an observation window 2 provided on the front of the test chamber body; the dimensions of the chamber are 6m×3m×3m (length×width×height), and the structure of the test chamber is designed as an integral structure. The chamber is made of 20 cm thick polyurethane foam board and ultra-fine fiber glass as heat insulation materials, and the volume is 37.5m 3 , a blower and an electric heating wire provided at the rear end of the chamber; the core refrigeration unit is 4 refrigeration compressors 12; the PLC control system 3 uses a Delta controller, the temperature control range is -60°C to 80°C, the operating power of the equipment is 55kW, which is used to simulate the alternating change of ambient temperature, and the overall error of the temperature control in the chamber is kept within 1°C to ±0.5°C.

[0037] Furthermore, as Figure 2 shown, the rainfall simulation device includes a water storage tank 13 located outside the test chamber, a water pump, a liquid transmission pipeline 10 and a rain shower head 5; the water pump is located in the water storage tank 13 and is connected to the power supply through a solenoid valve, which is used to control the rainfall amount, rainfall speed and rainfall duration of the rainfall simulation device; the water outlet 14 of the water pump is connected to the rain shower head 5 below the top of the test chamber body through the liquid transmission pipeline 10. The rain shower head can freely stretch up and down, adjust the angle and height according to the working conditions. By adjusting the rainfall amount, rainfall speed and rainfall duration, the simulation of actual rainfall conditions in cold regions can be realized.

[0038] In this embodiment, a water pump with a power of 30W is placed in the water storage tank 13. The water outlet 14 of the water pump is connected to the rain shower head 5 through a liquid transmission pipeline 10 with a diameter of 1.5 cm to form a rainfall simulation device for controlling rainfall, rainfall amount, rainfall speed and rainfall duration of the simulation device. The rainfall intensity simulated by this device can be controlled within 10-150 mm / h, and the rainfall uniformity coefficient is kept above 80%. The rain shower head can freely stretch and adjust its position according to the working conditions.

[0039] Furthermore, the solar radiation simulation device is multiple groups of adjustable ultraviolet lamps 9. The multiple groups of adjustable ultraviolet lamps 9 are arranged symmetrically and evenly below the top of the test chamber body, which is used to simulate different solar radiation angles and radiation amount changes. It can freely stretch up and down, adjust the angle and height according to the working conditions, and is used to simulate different solar radiation angles and radiation amount changes. By adjusting the solar radiation angle and radiation amount, the simulation of non-uniform temperature distribution inside the subgrade and ballastless track and non-uniform frost heave on the surface can be realized.

[0040] In this embodiment, a vertically telescopic steel pipe can also be installed at the upper part of the test chamber, and a universal fixture that can be adjusted 360° is installed at the end of the steel pipe. The adjustable ultraviolet lamp 9 is fixed by the universal fixture, so that the solar radiation amount and radiation angle can be freely adjusted. The radiation intensity simulated by this device can be controlled within 0 - 1500 W / m 2 , and the difference in radiation intensity is less than 50 W / m 2 .

[0041] Furthermore, as Figure 4 shown, the data acquisition and monitoring module includes a radiation sensor 18, a frost heave displacement meter 19, a temperature sensor 20, a moisture sensor 21, a laser displacement sensor 22, and a data acquisition instrument; the data acquisition instrument is connected to the radiation sensor 18, the frost heave displacement meter 19, the temperature sensor 20, the moisture sensor 21, and the laser displacement sensor 22 to monitor and collect the deformation displacement, temperature, moisture, and radiation data of the ballastless track - subgrade in real time.

[0042] Furthermore, the temperature sensor 20 is arranged inside the ballastless track structure and the subgrade structure for collecting the temperature change conditions inside the ballastless track and the subgrade. As Figure 4 , Figure 5 shown, the specific arrangement includes: 1) The temperature sensor 20 is arranged along the center of the cross-section of the subgrade structure, the center of the lower part of the base slab layer of the ballastless track, and the symmetric position on its left side. It starts to be arranged at 0.02 m below the top surface of the subgrade structure, and the vertical spacing from top to bottom is 0.1 m, with a total of 15, so as to monitor the horizontal and vertical ground temperature change laws of the subgrade structure during the freezing process; 2) The temperature sensor 20 is arranged vertically along the center of the ballastless track, with a total of 3; among them, 2 are respectively placed on the upper surface and the middle part of the track slab layer, and 1 is placed in the middle part of the base slab layer, so as to monitor the temperature change laws at different vertical positions of the ballastless track structure during the freezing process.

[0043] Furthermore, the moisture sensor 21 is arranged inside the subgrade structure for collecting the moisture change conditions inside the subgrade; as Figure 4 , Figure 6 shown, the moisture sensor 21 is arranged along the center of the cross-section of the subgrade structure, the center of the lower part of the base slab layer of the ballastless track, and the symmetric position on its left side. It starts to be arranged at 0.04 m below the top surface of the subgrade structure, and the vertical spacing from top to bottom is 0.1 m, with a total of 15, so as to monitor the horizontal and vertical moisture change laws of the subgrade structure during the freezing process.

[0044] Furthermore, the frost heave displacement meter 19 is arranged inside the subgrade structure for collecting the frost heave deformation amounts at different depths inside the subgrade; as Figure 4 , Figure 6As shown, two frost heave displacement gauges 19 are arranged at the center of the subgrade and the center of the left side of the subgrade to monitor the variation law of frost heave deformation of soil masses at different depths of the subgrade during the freezing process.

[0045] Three laser displacement sensors 22 are arranged on the laser displacement sensor clamping devices 23 on the left and right sides inside the test box body 1. The angles and height positions of the laser displacement sensors 22 can be freely adjusted through the laser displacement sensor clamping devices 23, which is convenient for monitoring the frost heave deformation laws of the ballastless track and the side slopes on the left and right sides of the subgrade.

[0046] Three radiation sensors 18 are arranged at the center of the upper surface of the subgrade structure and the surfaces of the side slopes on the left and right sides of the subgrade, which are used to monitor the variation law of the radiation amount received by the subgrade surface.

[0047] When conducting a simulation test using the simulation test device for the freezing characteristics of the ballastless track - subgrade based on cold region meteorological conditions in this embodiment of the invention, the following steps are included:

[0048] After the test preparation work is completed, start the core refrigeration unit composed of multiple refrigeration compressors 12, the PLC control system 3, and the data acquisition and monitoring module, test whether the core refrigeration unit and the data acquisition and monitoring module are in a normal working state, fit the typical air temperature in the severe cold region into a function and input it into the PLC control system 3 to make the temperature in the test box body 1 consistent with the actual on - site situation;

[0049] Control the temperature change in the test box body 1 through the PLC control system 3 to realize the freeze - thaw process of the ballastless track and the subgrade structure under a low - temperature environment, and real - time monitor the temperature, deformation of the ballastless track, and the temperature, moisture content and frost heave deformation of the subgrade through the data acquisition and monitoring module;

[0050] Start the rainfall simulation device and the solar radiation simulation device, add an appropriate amount of tap water to the water storage tank 13, turn on the water pump and the rain shower nozzle 5, and conduct rainfall simulation according to the required rainfall conditions; turn on the adjustable ultraviolet lamp 9, adjust the irradiation position of the ultraviolet lamp, and determine whether the radiation angle and radiation amount meet the requirements through the radiation sensor 18; observe the test process through the observation window 2 on the test box body 1 during the whole test process and take photos for record;

[0051] Through various data collected by the data acquisition instrument, clarify the freezing depth of the subgrade and the contribution degree of frost heave deformation of each soil layer, and compare and analyze the influence of the track structure on the upper part of the subgrade on the temperature and frost heave deformation of the subgrade structure.

[0052] The test time is determined by the scale - down theory. Based on the similarity theory, in similar phenomena, p and m can be used to represent the physical quantities corresponding to the prototype and the model respectively:

[0053] (π1) p= (π1) m ; (π1) p = (π1) m

[0054]

[0055] Thus, the similarity criterion is obtained:

[0056] where c is the similarity constant; l is the geometric dimension; a is the thermal diffusivity; λ is the thermal conductivity; t is the temperature; Q is the latent heat of water per unit volume; τ is the time;

[0057] Among the six similarity constants of the similarity criterion, four similarity constants can be arbitrarily selected (basic constants), and the remaining two are obtained by similarity theory.

[0058] The soil samples selected in this test are basically the same as those in the field. Therefore: c a = c Q = c λ = 1.

[0059] The temperature set in this test is the same as the temperature measured in the field. Therefore: c t = 1.

[0060] To simulate the measured results of the field observation site, then Therefore, the time scale is only related to the geometric scale, that is, the time scale is equal to the square of the geometric scale.

[0061] In this embodiment, the geometric scale adopted is 1:10. Therefore, the time scale is 1:100, that is, 87.6 hours in the test represents 365 days in reality. In this embodiment, two freeze-thaw cycle tests are carried out. Through the present invention, real-time monitoring of relevant parameters such as the temperature, deformation of the ballastless track in cold regions, and the temperature, moisture, and deformation of the subgrade can be realized, the freezing depth of the subgrade and the contribution degree of frost heave deformation of each soil layer can be clarified, and the influence of the ballastless track on the freezing characteristics of the subgrade structure can also be compared and analyzed.

[0062] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions, characterized in that: The device includes a programmable high and low temperature test chamber for controlling the alternating changes of ambient temperature, a rainfall simulation device for adjusting according to different rainfall amounts in cold regions, a solar radiation simulation device for adjusting according to different light intensity in cold regions, a ballastless track structure composed of a unit block structure, a roadbed structure composed of a three-layer structure, and a data acquisition and monitoring module for real-time monitoring and acquisition of deformation displacement, temperature, moisture, and radiation data; The ballastless track structure (11) comprises a track slab layer (15), a self-compacting concrete layer (16) and a base slab layer (17); the ballastless track structure (11) adopts a unit block structure, that is, three track slab layers (15) and three self-compacting concrete layers (16) are connected above the base slab layer (17); the track slab layer (15), the self-compacting concrete layer (16) and the base slab layer (17) are all made of cement; The roadbed structure comprises a subgrade surface layer (6), a subgrade bottom layer (7) and a lower earth-filled embankment (8); the subgrade surface layer (6) is made of graded crushed stone, and the subgrade bottom layer (7) and the lower earth-filled embankment (8) are both made of A / B group fillers; wherein the ballastless track structure is only laid on the right side of the upper surface of the roadbed structure, and is not laid on the left side of the upper surface of the roadbed structure.

2. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 1 is characterized by: The programmable high and low temperature test chamber comprises a test chamber body (1), a core refrigeration unit, a PLC control system (3), a test chamber door (4) and an observation window (2) arranged at the front of the test chamber body, and a fan and an electric heating wire arranged at the rear end of the chamber body; the core refrigeration unit is a plurality of refrigeration compressors (12); the PLC control system (3) adopts a Delta controller with a temperature control range of -60°C to 80°C and an equipment operating power of 55kW, which is used to simulate the alternating changes of the ambient temperature, and the overall error of the temperature control in the chamber is maintained at 1°C to ±0.5°C.

3. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 1 is characterized by: The rainfall simulation device comprises a water storage tank (13) located outside the test box, a water pump, a liquid transmission pipeline (10) and a shower nozzle (5); the water pump is located in the water storage tank (13) and is connected to a power source via an electromagnetic valve, and is used to control the rainfall amount, rainfall speed and rainfall duration of the rainfall simulation device; the water outlet (14) of the water pump is connected to the shower nozzle (5) below the top of the test box via the liquid transmission pipeline (10).

4. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 1 is characterized by: The solar radiation simulation device comprises a plurality of groups of adjustable ultraviolet lamps (9), which are arranged on the top of the test box and are symmetrically and evenly arranged to simulate different solar radiation angles and radiation amount changes.

5. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 1 is characterized by: The data acquisition and monitoring module comprises a radiation sensor (18), a frost heave displacement meter (19), a temperature sensor (20), a moisture sensor (21), a laser displacement sensor (22) and a data acquisition instrument; the data acquisition instrument is connected to the radiation sensor (18), the frost heave displacement meter (19), the temperature sensor (20), the moisture sensor (21) and the laser displacement sensor (22) to monitor and acquire deformation displacement, temperature, moisture and radiation data of the ballastless track-roadbed in real time.

6. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 5 is characterized by: The radiation sensors (18) are arranged at the center of the upper surface of the roadbed structure and on the slope surfaces on the left and right sides of the roadbed, a total of three, and are used to monitor the change pattern of the radiation amount received by the roadbed surface.

7. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 5 is characterized by: The frost heave displacement meter (19) is arranged inside the roadbed structure and is used to collect the frost heave deformation at different depths inside the roadbed; the frost heave displacement meter (19) is arranged at the center of the roadbed and the center of the left side of the roadbed, a total of two, to monitor the frost heave deformation change law of the soil at different depths of the roadbed during the freezing process.

8. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 5 is characterized by: The temperature sensors (20) are arranged inside the ballastless track structure and the roadbed structure, and are used to collect temperature changes inside the ballastless track and the roadbed. The specific arrangement includes: 1) the temperature sensors (20) are arranged along the center of the cross section of the roadbed structure, the lower roadbed of the center of the ballastless track base plate layer, and the symmetrical position on the left side, starting from 0.02m below the top of the roadbed structure, with a vertical spacing of 0.1m from top to bottom, and a total of 15, so as to monitor the horizontal and vertical ground temperature changes of the roadbed structure during the freezing process; 2) the temperature sensors (20) are arranged vertically along the center of the ballastless track, and a total of 3; 2 of them are respectively placed on the upper surface of the track plate layer and the middle of the track plate layer, and 1 is placed in the middle of the base plate layer, so as to monitor the temperature changes of the ballastless track structure at different vertical positions during the freezing process.

9. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 5 is characterized by: The moisture sensor (21) is arranged inside the roadbed structure and is used to collect moisture changes inside the roadbed. The moisture sensor (21) is arranged along the center of the cross section of the roadbed structure, the lower roadbed of the center of the ballastless track base plate layer and a symmetrical position on its left side, starting from 0.04m downward from the top of the roadbed structure, with a vertical spacing of 0.1m from top to bottom, and a total of 15 sensors, so as to monitor the lateral and vertical moisture changes of the roadbed structure during the freezing process.

10. The high-speed railway ballastless track-roadbed freezing characteristics simulation test device based on cold region meteorological conditions according to claim 5 is characterized by: The laser displacement sensors (22) are arranged on laser displacement sensor clamping devices (23) on the left and right sides of the test box body (1), with a total of three. The angle and height position of the laser displacement sensors (22) can be freely adjusted through the laser displacement sensor clamping devices (23), so as to facilitate monitoring of the frost heave deformation law of the ballastless track and the slopes on the left and right sides of the roadbed.

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