Sleeper lateral resistance testing device considering ballast track service state change

Abstract

The invention relates to a sleeper lateral resistance testing device considering the service state change of a ballast track. The sleeper lateral resistance testing device comprises a suspension assembly, a loading assembly and a measuring assembly, the suspension assembly comprises a suspension steel frame cross beam, a suspension steel frame side beam and a supporting cross beam; the suspension steel frame cross beam is installed on a steel rail, the supporting cross beam is installed on a sleeper, the suspension steel frame side beam is installed on a sliding rail of the supporting cross beam, and the side face of the suspension steel frame side beam is connected with the suspension steel frame cross beam; a side beam lower pressure sensor is mounted below the sliding rail; the loading assembly comprises two jacks which are arranged at symmetrical positions relative to a sleeper, and the jacks are arranged on a steel rail; the measuring assembly comprises a laser displacement sensor, a jack pressure sensor, a pressure data acquisition instrument, a displacement data acquisition instrument and a notebook computer; and continuous measurement of transverse resistance and displacement is realized. Compared with the prior art, the real service state can be kept; displacement can be accurately controlled; disturbance is reduced, and data reliability is high.

Description

Technical Field

[0001] The invention relates to the technical field of ballasted tracks, in particular to a sleeper lateral resistance testing device taking into account changes in the service state of the ballasted track. Background Art

[0002] The lateral resistance of the trackbed plays a crucial role in ensuring the stability of ballasted track. It prevents excessive lateral displacement of sleepers during service and rail buckling caused by high summer temperatures, thereby ensuring safe operation on ballasted railways. Train loads acting on the gravel trackbed of ballasted railways are complex, characterized by multidimensionality, randomness, and mobility. This often results in uneven deformation of the trackbed and subgrade during operation. Furthermore, due to the suspension effect of the rails, the support provided by the lower ballast to the sleeper bottom is often uneven. Existing research suggests that the lateral resistance of the trackbed is composed of three components: friction at the sleeper bottom, friction between the sleeper and the ballast, and ballast shoulder resistance. Field tests and discrete element simulations show that these three components contribute approximately 30%-50%, 15%-34%, and 26%-40% of the total lateral resistance, respectively. This indicates that friction at the sleeper bottom plays a major role in the lateral resistance of the trackbed. Uneven support at the sleeper bottom significantly reduces the lateral resistance provided by the sleeper bottom, thereby affecting the overall lateral stability of the trackbed. However, existing methods for measuring the lateral force of a single sleeper require the removal of the sleeper fasteners, completely separating the sleeper from the rail and placing it in a free-standing position. Under the influence of gravity, the sleeper's bottom is in full contact with the trackbed. Therefore, traditional lateral resistance testing methods cannot accurately reflect the lateral resistance of sleepers under different service conditions, especially those with uneven support at the bottom. Furthermore, traditional lateral resistance testing methods are prone to uncontrolled horizontal deflection of the sleeper during loading, which also affects the representativeness of the results.

[0003] Furthermore, existing multi-sleeper lateral resistance testing methods take into account, to some extent, the impact of the sleeper's actual support. However, since multiple sleepers are considered simultaneously, and their service conditions may vary, standard testing conditions are difficult to establish. Furthermore, the selection of the number of sleepers to be tested often lacks a rationale. Furthermore, multi-sleeper testing is large in scale, expensive, and time-consuming, making it difficult to meet the time window requirements of mainline railways.

[0004] Patent CN201710432793.8 discloses a device and method for testing the lateral resistance of sleepers in a transition section of a railway adhesive track bed. The device comprises a force frame, a loading rod, and a base plate fixed to one end of the loading rod; a hook bent toward the base plate at the other end of the loading rod; the base plate includes at least one loading surface facing away from the bending direction of the hook; the device further comprises a jack supported between the inner side inclined surface of the sleeper and the loading surface of the base plate; and a force sensor located between the jack and the loading surface of the base plate. However, the adaptability of the track bed is limited, and the suspension system requires sufficient free space at both ends of the sleeper. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a sleeper lateral resistance testing device that takes into account the changes in the service status of ballasted track, which can maintain the actual service status; can accurately control the displacement; reduce disturbances and have strong data reliability.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention proposes a testing device for the lateral resistance of a single rail sleeper, which can accurately measure the lateral resistance of the rail sleeper under actual service conditions, achieve a better restoration of the actual force and movement trajectory of the rail sleeper in use, and cause less disturbance to the roadbed.

[0008] After the fasteners are removed, the sleeper is completely separated from the rail, maintaining its original elevation in service and maintaining this elevation throughout the test. Maintaining a constant spacing between adjacent sleepers during the test reduces the impact of uneven horizontal constraints on the sleeper when it is completely free, enabling a more realistic simulation of the sleeper's actual lateral motion trajectory. This allows for the measurement of the sleeper's original lateral resistance characteristics.

[0009] The present invention provides a sleeper lateral resistance testing device that takes into account the changes in the service state of ballasted track, comprising: a suspension component, a loading component and a measuring component;

[0010] The suspension assembly is used to maintain the original elevation and service status of the test sleeper after the fasteners are removed; the suspension assembly includes: a suspension steel frame crossbeam, a suspension steel frame side beam, and a support crossbeam;

[0011] The suspension steel frame crossbeam is mounted on the rails, the support crossbeam is mounted on the sleepers, and the suspension steel frame side beams are mounted on the slide rails of the support crossbeams. The side surfaces of the suspension steel frame side beams are connected to the suspension steel frame crossbeams. A side beam lower pressure sensor is installed below the slide rails to measure the loads exerted on the support crossbeam by the suspension steel frame side beams and sleepers, thereby assessing the sleeper's original service condition. Because the weight of the sleeper to be tested is borne by two parts—the lower ballast and the suspended rails—the value measured by the side beam lower pressure sensor can be used to assess the sleeper's original service condition.

[0012] The suspension assembly can maintain the elevation and direction of the sleeper's working state during the test, maintain the original contact state between the sleeper bottom and the ballast, and then measure the lateral resistance of the sleeper in its actual service state.

[0013] The loading assembly includes two jacks installed at symmetrical positions about the sleeper, and the jacks are installed on the rails; the rails provide reaction fulcrums for the jacks, pushing the suspended steel frame beams and then pushing the sleepers to achieve bidirectional lateral resistance measurement of the sleepers; different from the traditional test in which the jacks are installed at the ends of the sleepers, the disturbance of the roadbed caused by the lateral resistance test is minimized.

[0014] The measurement assembly includes a laser displacement sensor, a jack pressure sensor, a pressure data acquisition device, a displacement data acquisition device, and a laptop computer. The laser displacement sensor is mounted on the lateral side of the sleeper, with the laser emission direction parallel to the direction of the sleeper's movement. The pressure data acquisition device receives signals from the jack pressure sensor, while the displacement data acquisition device receives signals from the laser displacement sensor. This enables continuous measurement of lateral resistance and displacement. If power is unavailable, conventional displacement meters and pressure gauges can be used to obtain discrete data on steady-state lateral resistance and displacement during testing.

[0015] Furthermore, the suspension steel frame crossbeam is installed on the rail through inner bolts, and the support crossbeam is installed on the sleeper through inner bolts.

[0016] Furthermore, the suspension steel frame crossbeam, suspension steel frame side beams, and support beams are all symmetrical structures. Due to the symmetrical structure of the suspension assembly, after completing the lateral resistance test on one side, the loading system can be installed on the rail on the other side and the lateral resistance test on the other side can be performed again, serving as a reference for evaluating the bidirectional lateral resistance of the trackbed.

[0017] Furthermore, the slide rails provide a track for the sleepers to move, and the friction between the slide rails and the side beams of the suspension steel frame is calibrated through preliminary tests. Because part of the weight of the suspension steel frame crossbeams and sleepers acts on the slide rails, friction exists between the slide rails and the side beams of the suspension steel frame, which can be calibrated through preliminary tests.

[0018] Furthermore, the calibration process through preliminary tests includes: fixing the support beam in the laboratory, using a jack to apply a load vertically downward at the bolts of the suspension steel frame beam, applying a lateral force through the jack to push the steel frame beam, recording multiple sets of vertical-lateral pressure data, and fitting to obtain the dynamic friction coefficient between the support beam and the suspension steel frame side beam.

[0019] The specific process of calibration through preliminary testing includes:

[0020] S1: First, loosen the inner bolts of the two adjacent sleepers to be tested and remove the fasteners. Then, install the suspension assembly. At this time, there is no sleeper suspended below the suspension assembly.

[0021] S2: Install the loading assembly, which consists of two jacks. The two jacks are installed symmetrically on both sides of the sleeper. The push point is the suspended steel frame beam, and the reaction force support is the rail;

[0022] S3: Install the sensor support and laser displacement sensor on the lateral side of the sleeper according to the push direction of the sleeper;

[0023] S4: A pressure sensor is installed below the side beam of the suspended steel frame to reflect the pressure exerted by the side beam of the suspended steel frame on the supporting beam; this pressure data is used to determine the resistance of the slide rail.

[0024] S5: During calibration, fix the two supporting beams in the laboratory, and fix the suspension steel frame side beams on the slide rails of the supporting side beams. The distance between the supporting beams and the suspension steel frame side beams is the same as that in the lateral resistance test.

[0025] S6: Instead of suspending the sleepers from the lower part of the suspension steel frame side beam, a small jack is used to apply a vertical downward load to the bolts of the suspension steel frame cross beam. At this time, the pressure sensor at the lower part of the side beam has a reading. The jack is used to apply a lateral force to the suspension steel frame cross beam until it can push the suspension steel frame cross beam.

[0026] S7: Obtain and record the lateral force value through the jack pressure sensor, and obtain and record the load applied by the small jack to the suspended steel frame beam through another pressure sensor;

[0027] S8: During the calibration process, the vertical load applied by the small jack to the suspended steel frame beam is 0 to 3800N (approximately the gravity of a single rail sleeper), with an interval of 100N, and multiple sets of different vertical-transverse jack pressure data are obtained.

[0028] S9: Based on the obtained multiple sets of data, the dynamic friction coefficient between the supporting beam and the side beam of the suspension steel frame can be fitted.

[0029] S10: After obtaining the jack pressure sensor value during the actual measurement process, the previously calibrated dynamic friction coefficient is multiplied by the jack pressure sensor value to obtain the friction value between the support beam and the suspension steel frame side beam. The friction portion is deducted from the final jack pressure sensor value to obtain the actual sleeper lateral resistance value under service conditions.

[0030] Furthermore, the side beams of the suspended steel frame are fixed to slide rails, which provide a track for pushing. Two jacks apply a pushing load to the suspended steel frame crossbeams. During the test, the sleeper's displacement direction follows the slide rails, preventing displacement deviation. This avoids displacement deviation caused by uneven ballast support on both sides of the sleeper during pushing, improving the accuracy of lateral resistance measurements.

[0031] Furthermore, the suspension assembly further comprises: a lateral adjustment knob and a vertical adjustment knob;

[0032] Taking into account the randomness of the service status of the sleepers on site, there may be differences in the elevation and lateral position of the sleeper to be tested and the adjacent sleepers, making the installation of the test device difficult. For this reason, lateral adjustment knobs and vertical adjustment knobs are set on both sides of the suspended steel frame beam; during the installation of the suspended steel frame beam, the lateral adjustment knobs and vertical adjustment knobs can be adjusted according to the original service status of the sleeper to expand and contract horizontally and vertically to complete the installation.

[0033] Furthermore, after the installation of the suspension steel frame crossbeam is completed, the outer bolts of the sleeper can be removed and the original service state can be maintained.

[0034] Furthermore, the laser displacement sensor is arranged on a sensor support.

[0035] Furthermore, the jack pressure sensor is directly integrated into the hydraulic system of the jack.

[0036] The operating steps of the test device to measure the lateral resistance of the track bed are as follows:

[0037] Remove the inner bolts and fasteners of the sleeper and its adjacent sleepers;

[0038] Install the suspension steel frame crossbeam on the sleeper through the inner bolts, and install the support crossbeam on the two adjacent sleepers through the inner bolts;

[0039] The suspension rail crossbeam is installed on the slide rail of the support beam through the suspension rail side beam, so that the sleeper maintains its original elevation and service state. Considering that the original service state of the sleeper is very random, the suspension steel frame crossbeam can be adjusted through the horizontal adjustment knob and the vertical adjustment knob during the installation process to facilitate installation;

[0040] A jack is installed at each longitudinal symmetrical position of the sleeper, with the rail as the reaction fulcrum, pushing the suspension steel frame beam;

[0041] A sensor support and a laser displacement sensor are installed on one lateral side of the sleeper to measure the lateral displacement of the sleeper;

[0042] Lay out the jack pressure sensor, pressure data collector, displacement data collector, and laptop computer.

[0043] Remove the outer bolts of the test sleeper to separate the sleeper from the rail, and keep it in its original service state completely by the suspension assembly;

[0044] Slowly push the sleeper and measure the curve of the jack pressure changing with the sleeper displacement. Based on the friction coefficient calibrated in advance, calculate the curve of the lateral resistance changing with the sleeper displacement.

[0045] Compared with the prior art, the present invention has the following advantages:

[0046] (1) Ability to maintain the actual service state. The original elevation and contact state of the sleeper are accurately maintained through the suspension assembly. The combined structure of the suspension steel frame beam and the support beam can maintain the original posture of the sleeper even after the fasteners are removed. The suspension state is monitored in real time through the pressure sensor under the side beam to ensure that the test conditions are consistent with the actual service state, solving the measurement distortion problem caused by the free deformation of the sleeper in traditional testing methods.

[0047] (2) Capable of precise displacement control and wide adaptability. The linear guide system provided by the slide rail ensures that the sleeper moves only in the set direction, avoiding irregular offset; the symmetrical loading design of the double jacks ensures the consistency of the thrust direction. The slide rail on the support beam provides a displacement track for the suspended steel frame beam and sleepers, so that the distance between the test sleeper and the adjacent sleepers remains unchanged during the test, reducing the impact of uneven constraints in the horizontal plane when the sleeper is completely free.

[0048] (3) Reduced disturbance and strong data reliability. Using the rail as the reaction force fulcrum reduces interference with the trackbed compared to traditional sleeper end support methods. The symmetrical loading system allows for bidirectional testing, allowing multiple sets of data to be collected in one installation. Precise friction coefficients are obtained through preliminary laboratory calibration. Real-time data fusion processing technology automatically deducts system errors, providing effective data for measuring the lateral stability of ballasted sleepers on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the structure of the sleeper lateral resistance test device considering the changes in the service status of ballasted track;

[0050] Figure 2 For the Figure 1 A side view of the section AA shown;

[0051] Figure 3 For the Figure 1 Side view of section BB shown.

[0052] Figure markings: 1-rail, 2-sleeper, 3-inner bolt, 4-outer bolt, 5-fastener, 6-jack, 7-slide rail, 8-support beam, 9-suspension steel frame beam, 10-suspension steel frame side beam, 11-side beam lower pressure sensor, 12-laser displacement sensor, 13-sensor support, 14-jack pressure sensor, 15-pressure data collector, 16-displacement data collector, 17-laptop computer, 18-lateral adjustment knob, 19-vertical adjustment knob. DETAILED DESCRIPTION

[0053] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0054] Example 1

[0055] This embodiment provides a sleeper lateral resistance testing device that takes into account the changes in the service status of ballasted track. Figure 1-3 As shown, it includes: a suspension component, a loading component and a measuring component;

[0056] The suspension assembly is used to maintain the original elevation and service state of the test sleeper after the fastener 5 is removed; the suspension assembly includes: a suspension steel frame crossbeam 9, a suspension steel frame side beam 10, and a support beam 8;

[0057] The suspension steel frame crossbeam 9 is mounted on the rail 1, the support crossbeam 8 is mounted on the sleeper 2, and the suspension steel frame side beam 10 is mounted on the slide rail 7 of the support crossbeam 8. The side of the suspension steel frame side beam 10 is connected to the suspension steel frame crossbeam 9. A side beam lower pressure sensor 11 is installed below the slide rail 7 to measure the load applied to the support crossbeam 8 by the suspension steel frame side beam 10 and the sleeper 2, thereby evaluating the original service condition of the sleeper 2. Since the weight of the sleeper to be tested is borne by two parts, the lower ballast and the suspended rail, the value measured by the side beam lower pressure sensor 11 can be used to evaluate the original service condition of the sleeper 2.

[0058] The suspension assembly can maintain the elevation and direction of the sleeper 2 in its working state during the test, maintain the original contact state between the bottom of the sleeper and the ballast, and then measure the lateral resistance of the sleeper 2 in its actual service state.

[0059] The loading assembly includes two jacks 6 installed at symmetrical positions about the sleeper 2, and the jacks 6 are installed on the rail 1; the rail 1 provides a reaction fulcrum for the jacks 6, pushing the suspended steel frame beam 9 and then pushing the sleeper 2 to achieve bidirectional lateral resistance measurement of the sleeper 2; different from the traditional test in which the jacks are installed at the ends of the sleeper, the disturbance of the roadbed caused by the lateral resistance test is minimized.

[0060] The measurement assembly includes a laser displacement sensor 12, a jack pressure sensor 14, a pressure data acquisition device 15, a displacement data acquisition device 16, and a laptop computer 17. The laser displacement sensor 12 is mounted on a lateral side of the sleeper 2, with the laser emission direction parallel to the push direction of the sleeper 2. The pressure data acquisition device 15 receives signals from the jack pressure sensor 14, and the displacement data acquisition device 16 receives signals from the laser displacement sensor 12, enabling continuous measurement of lateral resistance and displacement. If power is unavailable, conventional displacement meters and pressure gauges can be used to obtain discrete data on steady-state lateral resistance and displacement during the test.

[0061] In a specific embodiment, the suspension steel frame crossbeam 9 is mounted on the rail 1 through inner bolts 3 , and the support crossbeam 8 is mounted on the sleeper 2 through inner bolts 3 .

[0062] In this embodiment, the suspension steel frame crossbeam 9, suspension steel frame side beams 10, and support beam 8 are all symmetrical structures. Because the suspension assembly is symmetrical, after completing the lateral resistance test on one side, the loading system can be installed on the rail on the other side, and the lateral resistance test on the other side can be performed again, serving as a reference for evaluating the bidirectional lateral resistance of the trackbed.

[0063] In a specific embodiment, the slide rail 7 provides a track for the sleeper 2 to move. The friction between the slide rail 7 and the suspension steel frame side beam 10 is calibrated through preliminary testing. Since part of the weight of the suspension steel frame cross beam 9 and the sleeper 2 acts on the slide rail 7, friction exists between the slide rail 7 and the suspension steel frame side beam 10, which can be calibrated through preliminary testing.

[0064] In a specific embodiment, to measure the sleeper's lateral resistance, the sleeper's lateral displacement must be measured. To do this, a jack 6 is used to apply a lateral force to the suspension steel frame beam 9. Since the sleeper being tested is suspended during the test, part of its gravity is borne by the support beam. Consequently, friction exists between the support beam 8 and the suspension steel frame side beam 10. This friction, combined with the sleeper's lateral resistance, balances the lateral force applied by the jack. Consequently, the result measured by the jack pressure sensor 14 is biased and inaccurately reflects the sleeper's lateral resistance. To improve measurement accuracy, make the experimental results more convincing, and better reflect the sleeper's actual service life, the friction between the support beam 8 and the suspension steel frame side beam 10 must be calibrated and deducted from the measurement results of the jack pressure sensor 14. This calibration process requires an additional small jack and another pressure sensor.

[0065] The initial steps are similar to those for the formal measurement of the sleeper's lateral resistance. First, loosen the inner bolts 3 of the test sleeper and its two adjacent sleepers and remove the fasteners 5. Then, use the inner bolts 3 to install the support beam 8 and the suspension steel frame beam 9. The suspension steel frame beam 9 is mounted on the slide rail 7 of the support beam 8 via the suspension steel frame side beams 10. After the suspension steel frame beam 9 and support beam 8 are installed, remove the outer bolts 4 and corresponding fasteners 5 of the test sleeper to completely separate the test sleeper from the rail 1. Then, install the loading system, which consists of two jacks 6, which are installed symmetrically on either side of the test sleeper longitudinally. The push point is the suspension steel frame beam 9, and the reaction point is the rail 1. Finally, install the sensor support 13 and laser displacement sensor 12 on the lateral side of the test sleeper according to the sleeper's push direction. To ensure measurement accuracy, the distance between the sensor support 13 and the laser displacement sensor 12 and the test sleeper should be determined according to the sensor parameters. A side beam lower pressure sensor 11 is installed below the suspension steel frame side beam 10 to reflect the pressure applied by the suspension steel frame side beam 10 to the supporting cross beam 8.

[0066] During calibration, two support beams 8 are fixed in the laboratory, and the suspended steel frame side beams 9 are fixed to the slide rails 7 of the support beams 8. The distance between the support beams 8 and the suspended steel frame side beams 9 is the same as in the lateral resistance test. Instead of suspending rail sleepers from the lower portion of the suspended steel frame side beams, a small jack is used to apply a vertical downward load to the bolts of the suspended steel frame cross beams 9. At this point, the pressure sensor 11 at the lower portion of the side beam has a reading. A lateral force is then applied to the suspended steel frame cross beams 9 using the jack 6 until it pushes the steel frame cross beams. The lateral force value is recorded using the jack pressure sensor 14, and the load applied to the suspended steel frame cross beams 9 by the small jack is recorded using another pressure sensor. During the calibration process, the small jack applies a vertical load of 0 to 3800 N (approximately the weight of a single rail sleeper) to the suspension steel frame crossbeam, with intervals of 100 N, to obtain multiple sets of different vertical-transverse jack pressure data. The specific number of operations can be determined by the actual project needs. In principle, the number of operations should not be too small and should be appropriately increased to improve measurement accuracy. Based on the multiple sets of data obtained, the dynamic friction coefficient between the support beam 8 and the suspension steel frame side beam 10 can be fitted, and the relationship between the value of the jack pressure sensor 14 and the actual friction force can be further obtained. When using the present invention to actually measure the lateral resistance of the sleeper, after obtaining the value of the jack pressure sensor 14, the previously calibrated dynamic friction coefficient should be multiplied by the value of the jack pressure sensor 14 to obtain the friction force value between the support beam 8 and the suspension steel frame side beam 10. The friction force portion is deducted from the final value of the jack pressure sensor 14, which is the value of the sleeper lateral resistance under actual service conditions.

[0067] The friction force between the supporting crossbeam 8 and the suspension steel frame side beam 10 can be calculated by the following formula:

[0068] F f =(F N +G)×μ

[0069] Where, F f —Friction force (N), measured by the jack pressure sensor 14 during the preliminary calibration process; G—Gravity of the suspended steel frame beam (N), no measurement is required; F N —The vertical load (N) applied to the suspended steel frame crossbeam 9 by a small jack during the preliminary calibration process; μ—dynamic friction coefficient, dimensionless, which can be fitted by plotting the slope of multiple sets of data get.

[0070] F=F x -F f

[0071] Where, F x —Total lateral resistance (N), measured by the jack pressure sensor 14 during the formal test of the sleeper lateral resistance; F—Sleeper lateral resistance (N).

[0072] It should be emphasized that during the friction calibration process, the following precautions should be taken:

[0073] 1. Temporarily do not use the suspension steel frame crossbeam 9 to fix the sleeper to be measured. If it is fixed, the formal measurement of the sleeper lateral resistance has already begun, and the friction force between the supporting crossbeam 8 and the suspension steel frame side beam 10 cannot be deducted from the measurement result of the jack pressure sensor 14;

[0074] 2. In addition, when using a small jack to apply vertical load, it is necessary to keep it in the middle of the suspension steel frame beam 9 and not apply it to one side or one corner of the beam to avoid affecting the measurement accuracy;

[0075] 3. The jack 6 is required to apply a lateral force to the suspension steel frame crossbeam 9 until it can be pushed at a constant speed. This is to measure the coefficient of kinetic friction between the support crossbeam 8 and the suspension steel frame side beam 10. This is because the friction between the support crossbeam 8 and the suspension steel frame side beam 10 during the process of pushing the suspension steel frame crossbeam 9 during the actual measurement of the sleeper's lateral resistance is kinetic friction. As we all know, the maximum coefficient of static friction between two rigid bodies is slightly larger than the coefficient of kinetic friction. During the friction calibration process, when applying a lateral force to the suspension steel frame crossbeam 9 using the jack 6, the value of the jack pressure sensor 14 should not be recorded at the exact moment of pushing. This is because the sensor value recorded at the moment of pushing reflects the maximum static friction between the support crossbeam 8 and the suspension steel frame side beam 10, which is inconsistent with the purpose of measuring kinetic friction.

[0076] 4. During the measurement of the lateral resistance of the sleeper, the sleeper maintained its original service state, and its gravity was borne by the bottom ballast and the suspension steel frame crossbeam 9. The data obtained by the pressure sensor 11 at the lower part of the side beam was not equal to the gravity of the test sleeper.

[0077] In this embodiment, the suspension steel frame side beams 10 are fixed to slide rails 7, which provide a track for pushing. Two jacks 6 apply a pushing load to the suspension steel frame cross beams 9. During the test, the sleeper 2 is displaced along the slide rails 7, preventing displacement direction deviation. This avoids displacement direction deviation caused by uneven ballast support on both sides of the sleeper during pushing, improving the accuracy of lateral resistance measurement.

[0078] In a specific embodiment, the suspension assembly further includes: a lateral adjustment knob 18 and a vertical adjustment knob 19;

[0079] Taking into account the randomness of the service status of the on-site sleepers, there may be differences in the elevation and lateral position of the sleeper to be tested and the adjacent sleepers, making the installation of the test device difficult. For this reason, lateral adjustment knobs 18 and vertical adjustment knobs 19 are set on both sides of the suspension steel frame beam 9; during the installation process of the suspension steel frame beam 9, the lateral adjustment knobs 18 and vertical adjustment knobs 19 can be adjusted according to the original service status of the sleeper 2 to expand and contract horizontally and vertically to complete the installation.

[0080] In a specific embodiment, after the suspension steel frame crossbeam 9 is installed, the outer bolts 4 of the sleeper 2 can be removed and the original service state can be maintained.

[0081] In a specific embodiment, the laser displacement sensor 12 is disposed on a sensor support 13 .

[0082] In a specific embodiment, the jack pressure sensor 14 is directly integrated into the hydraulic system of the jack 6 .

[0083] The operating steps of the test device to measure the lateral resistance of the track bed are as follows:

[0084] Remove the sleeper 2 and the inner bolts 3 and fasteners 5 adjacent to the sleeper 2;

[0085] Install the suspension steel frame crossbeam 9 on the sleeper 2 through the inner bolts 3, and install the support crossbeam 8 on the two adjacent sleepers 2 through the inner bolts 3;

[0086] The suspension rail crossbeam 9 is installed on the slide rail 7 of the support beam 8 through the suspension rail side beam 10, so that the sleeper 2 maintains its original elevation and service state. Considering that the original service state of the sleeper 2 is very random, the suspension steel frame crossbeam 9 can be adjusted by the horizontal adjustment knob 18 and the vertical adjustment knob 19 during the installation process to facilitate installation;

[0087] A jack 6 is installed at each longitudinal symmetrical position of the sleeper 2, with the rail 1 as the reaction force fulcrum, pushing the suspension steel frame beam 9;

[0088] A sensor support 13 and a laser displacement sensor 12 are installed at a position on one lateral side of the sleeper 2 to measure the lateral displacement of the sleeper 2;

[0089] The jack pressure sensor 14, pressure data collector 15, displacement data collector 16, and laptop computer 17 are arranged.

[0090] Remove the outer bolts 4 of the test sleeper to separate the sleeper 2 from the rail 1, and keep it in its original service state completely by the suspension assembly;

[0091] Slowly push sleeper 2 and measure the curve of jack pressure versus sleeper displacement. Calculate the curve of lateral resistance versus sleeper displacement based on the previously calibrated friction coefficient. To measure lateral resistance, first reset the displacement sensor 12 to zero. Then, slowly load the suspended steel frame crossbeam 9 using jack 6, while simultaneously collecting the lateral displacement and load of sleeper 2. The collection interval should not exceed 0.2mm, and the collection points should be appropriately increased around every 2mm of lateral displacement of sleeper 2. The lateral resistance of the trackbed is determined by the lateral force applied when sleeper 2 has a 2mm lateral displacement.

[0092] This device takes into account the changes in the service status of ballasted track sleepers and can better reflect the actual stress conditions of the sleepers. The device mainly includes a suspension component, a loading component and a measurement component. The suspension assembly includes a suspension steel frame crossbeam 9, a suspension steel frame side beam 10, a support crossbeam 8, a slide rail 7, a lateral adjustment knob 18, a vertical adjustment knob 19 and an inner bolt 3, which can suspend the test sleeper to maintain its original elevation in service state, and can keep the elevation of the sleeper unchanged during the test, thereby reflecting the actual contact state between the sleeper and the track bed during service. The support crossbeam is covered with a slide rail, which can provide a track for pushing the suspension steel frame crossbeam and the sleeper, so that the distance between the sleeper and the adjacent sleeper remains unchanged during the test, avoiding the influence of the ballast on the uneven longitudinal support of the test sleeper; the loading assembly is mainly composed of two jacks 6, which push the suspension steel frame crossbeam 9 during the test, and then push the sleeper. Its reaction force fulcrum is the rail 1, which reduces the disturbance of the track bed by the lateral resistance test device. In addition, the loading system can be fixed on the rail 1 on different sides according to the pushing direction, thereby realizing the measurement of bidirectional lateral resistance. The measuring assembly includes a sensor support 13, a laser displacement sensor 12, a jack pressure sensor 14, a pressure data acquisition instrument 15, a displacement data acquisition instrument 16, and a laptop computer 17, which are used to measure the lateral displacement of the test sleeper. The sensor support 13 and the laser displacement sensor 12 are installed on the lateral side of the test sleeper to avoid being disturbed by the displacement of the rail 1 (the rail is the reaction force fulcrum of the loading system) when installed on the rail.

[0093] The present invention is helpful to study the lateral resistance characteristics of sleepers under different service conditions, thereby providing a reference for ballasted track design and its maintenance and repair.

[0094] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0095] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A sleeper lateral resistance testing device taking into account the changes in the service status of ballasted track, characterized in that: include: Suspension assembly, loading assembly and measurement assembly; The suspension assembly is used to maintain the original elevation and service state of the test sleeper after the fastener (5) is removed; the suspension assembly comprises: a suspension steel frame crossbeam (9), a suspension steel frame side beam (10), and a support crossbeam (8); The suspension steel frame cross beam (9) is installed on the rail (1), the support cross beam (8) is installed on the sleeper (2), the suspension steel frame side beam (10) is installed on the slide rail (7) of the support cross beam (8), and the side of the suspension steel frame side beam (10) is connected to the suspension steel frame cross beam (9); a side beam lower pressure sensor (11) is installed below the slide rail (7) for measuring the load acting on the support cross beam (8) by the suspension steel frame side beam (10) and the sleeper (2), and evaluating the original service state of the sleeper (2); The loading assembly comprises two jacks (6) installed at symmetrical positions about the sleeper (2), and the jacks (6) are installed on the rail (1); the rail (1) provides a reaction force fulcrum for the jacks (6), which pushes the suspended steel frame crossbeam (9) and then pushes the sleeper (2), so as to realize the bidirectional lateral resistance measurement of the sleeper (2); The measuring assembly comprises: a laser displacement sensor (12), a jack pressure sensor (14), a pressure data acquisition instrument (15), a displacement data acquisition instrument (16) and a laptop computer (17); the laser displacement sensor (12) is installed on a lateral side of the sleeper (2), and the laser emission direction is parallel to the pushing direction of the sleeper (2); the pressure data acquisition instrument (15) receives the signal of the jack pressure sensor (14), and the displacement data acquisition instrument (16) receives the signal of the laser displacement sensor (12); and continuous measurement of lateral resistance and displacement is achieved.

2. A sleeper lateral resistance testing device considering changes in the service state of ballasted track according to claim 1, characterized in that: The suspension steel frame cross beam (9) is mounted on the steel rail (1) via inner bolts (3), and the support cross beam (8) is mounted on the sleeper (2) via inner bolts (3).

3. The sleeper lateral resistance testing device considering the change of the service state of the ballasted track according to claim 1 is characterized in that: The suspension steel frame cross beam (9), the suspension steel frame side beam (10) and the support cross beam (8) are all symmetrical structures.

4. The sleeper lateral resistance testing device considering the change of the service state of the ballasted track according to claim 1 is characterized in that: The slide rail (7) provides a track for pushing the sleeper (2), and the friction force between the slide rail (7) and the suspension steel frame side beam (10) is calibrated through preliminary tests.

5. The sleeper lateral resistance testing device considering the change of the service state of the ballasted track according to claim 1 is characterized in that: The calibration process through preliminary tests includes: fixing the support beam (8) in a laboratory, applying a load vertically downward at the bolts of the suspension steel frame beam (9) using a small jack, applying a lateral force to push the steel frame beam through the small jack, recording multiple sets of vertical-lateral pressure data, and fitting to obtain the dynamic friction coefficient between the support beam (8) and the suspension steel frame side beam (10).

6. The sleeper lateral resistance testing device considering the change of the service state of the ballasted track according to claim 1 is characterized in that: The suspension steel frame side beam (10) is fixed on the slide rail (7), the slide rail (7) provides a track for pushing, and a pushing load is applied to the suspension steel frame cross beam (9) through two jacks (6). During the test, the displacement direction of the sleeper (2) is along the direction of the slide rail (7) to avoid displacement direction deviation.

7. The sleeper lateral resistance testing device considering the change of the service state of the ballasted track according to claim 1 is characterized in that: The suspension assembly further comprises: a lateral adjustment knob (18) and a vertical adjustment knob (19); During the installation process of the suspended steel frame crossbeam (9), the lateral adjustment knob (18) and the vertical adjustment knob (19) can be adjusted according to the original service state of the sleeper (2) to expand and contract in the lateral and vertical directions to complete the installation.

8. The sleeper lateral resistance testing device taking into account the change in the service state of the ballasted track according to claim 7, characterized in that: After the installation of the suspension steel frame crossbeam (9) is completed, the outer bolts (4) of the sleeper (2) can be removed and the original service state can be maintained.

9. The sleeper lateral resistance testing device considering the change of the service state of the ballasted track according to claim 1 is characterized in that: The laser displacement sensor (12) is arranged on a sensor support (13).

10. The sleeper lateral resistance testing device considering the change of the service state of the ballasted track according to claim 1, characterized in that: The jack pressure sensor (14) is directly integrated into the hydraulic system of the jack (6).

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