JP5767491B2 - Sleeper damping structure - Google Patents

Description

  The present invention relates to a sleeper damping structure applied to a sleeper on a ballast track.

  In the so-called ballast track with ballast composed of crushed stone and gravel as the roadbed, the dynamic load from the train is transmitted to the ballast through the sleepers, and the vibration energy of the entire track is caused by the friction between the ballasts at that time. Some change to thermal energy.

  Therefore, unlike a slab track with a concrete track slab as a roadbed, noise and vibration are greatly suppressed in a ballast track. And further causes uneven settlement of the bed.

  For this reason, track maintenance work such as replacing ballasts is indispensable for ballast tracks, but measures to prevent uneven settlement of the roadbed have been proposed or implemented from various viewpoints in order to reduce such work.

JP 2010-255249 A JP 2003-013402 A JP 2002-129501 A JP 2010-185242 A JP-A-10-81827 Japanese Patent Laid-Open No. 9-11704

  As measures to prevent uneven settlement of the road bed, a viscoelastic material is interposed between the road bed and a sleeper placed on the top of the road bed (Patent Documents 1 to 3), or a load directly under the sleeper. Are known (Patent Document 4), filling the gap between the roadbed with a solidified material (Patent Document 5), and increasing the connection strength between the roadbed and sleepers (Patent Document 6). .

  However, if the above-mentioned measures are applied to the existing ballast track, large-scale construction is required, resulting in a problem that the economy is poor and that the train operation must be stopped during the construction period. As a countermeasure to prevent subsidence of the road bed, it was not always sufficient.

  Further, in the method of filling the gap between the roadbeds with the caking material, the structure of the roadbed is changed, and there is a problem that the advantages unique to the ballast track that can reduce noise and vibration are lost.

  The present invention has been made in consideration of the above-described circumstances, and is a sleep control system that can more reliably and economically prevent the subsidence of the roadbed without hindering train operation or changing the structure of the roadbed. An object is to provide a vibration structure.

In order to achieve the above object, a sleeper damping structure according to the present invention includes, as described in claim 1, a tuned mass damper installed on a sleeper placed near the top end of a ballast made of ballast, the natural frequency of the tuned mass damper, of vibrations during running trains generated on the sleepers, in Rukoto substantially coincide to the target frequency a frequency corresponding to the vibration that causes subsidence of the track bed as a target frequency The vibration of the sleeper is configured to be suppressed .
Further, the sleeper damping structure according to the present invention is configured such that the tuning mass damper is formed by laminating a steel plate as a mass body and a rubber sheet as an elastic body that freely supports the mass body, The mass of the steel sheet and the rigidity of the rubber sheet are determined so that the natural frequency substantially matches the target frequency.

  In the sleeper damping structure according to the present invention, the target frequency is obtained by actually measuring the vibration of the sleeper when the train travels and frequency-analyzing the time history vibration data.

  In the sleeper damping structure according to the present invention, the target frequency is obtained by performing eigenvalue analysis on the sleeper vibration model.

  In the sleeper damping structure according to the present invention, the target frequency is set to a natural frequency corresponding to a bending mode around a horizontal axis in which both ends of the sleeper are in opposite phases to the central portion.

  In the sleeper damping structure according to the present invention, the tuning mass damper is attached in the vicinity of both ends of the sleeper.

  In the sleeper damping structure according to the present invention, the tuned mass damper is installed in a sleeper disposed in the vicinity of a portion of the sleeper where the joint between rails or the structure of the roadbed changes.

  The ballast track includes, for example, a road bed made of ballast stacked in a trapezoidal shape on a roadbed, a plurality of sleepers arranged in a row along the material axis direction of the road bed near the top end of the road bed, and the pillows. A dynamic load from a train traveling on the rail is transmitted sequentially from the rail to the sleeper and from the sleeper to the roadbed. In the structure, a tuned mass damper is installed in the sleeper placed near the top of the road bed made of ballast, and the natural frequency of the tuned mass damper is the vibration generated during the train running in the sleeper, The frequency corresponding to the vibration that causes the subsidence of the road bed is set as the target frequency so as to substantially match the target frequency.

  In this way, the vibration of the sleeper that causes the subsidence of the bed is quickly converged by the tuned mass damper, and the kinetic energy transmitted from the sleeper to the bed is also reduced as the vibration converges.

  Therefore, the ballast is prevented from being damaged due to the load of the dynamic load from the sleeper to the road bed, and the road bed can be prevented from sinking. In addition, since only a tuned mass damper is attached to the sleeper, simple construction is sufficient and the influence on train operation can be minimized.

  The tuned mass damper is also referred to as TMD (Tuned Mass Damper), and includes a mass body and an elastic body that supports the mass body in a freely oscillating manner. The frequency corresponding to the vibration that causes the subsidence of the road bed is set as the target frequency, and the mass body and the elastic body are adjusted so that the natural frequency of the tuned mass damper substantially matches the target frequency. Configure.

  The tuned mass damper is configured such that the mass body vibrates in the same direction as the vibration that causes the subsidence of the road bed, that is, the vibration at the target frequency. Specifically, in the example in which the mass body is a steel plate, the elastic body is a rubber sheet, and they are laminated to each other, when the vibration at the target frequency is in the vertical direction, the steel sheet is in the axial rigidity of the rubber sheet. When the vibration at the target frequency is in the horizontal direction, the steel sheet may be vibrated with the shear rigidity of the rubber sheet.

  How to calculate the target frequency is arbitrary. For example, by actually measuring the vibration of the sleeper that occurs during train travel and frequency analysis of the time history vibration data, or as needed Each model can be obtained by modeling together with the rail and the roadbed and performing eigenvalue analysis on the vibration model.

  Here, when calculating the target frequency by eigenvalue analysis, if the target frequency is the natural frequency corresponding to the bending mode around the horizontal axis where both ends of the sleeper are in opposite phase to the center, Of the dynamic load acting on the sleeper, the transmission of the non-uniform load over the bottom surface of the sleeper is suppressed, and it is possible to prevent damage to the ballast caused by the non-uniform dynamic load. Become.

  As long as the tuned mass damper can suppress the vibration of the sleeper that causes subsidence, it can be installed in the center of the sleeper, and it may be installed in the center of the sleeper. When it is attached, vibration that causes subsidence of the roadbed can be reliably suppressed.

  In other words, according to the eigenvalue analysis of sleepers performed by the present applicant, the rigid body mode in which the whole sleeper vibrates, and the bending mode around the horizontal axis or the vertical axis where both ends of the sleeper are opposite in phase to the center are low order. Therefore, it is possible to suppress the vibration of the entire sleeper by suppressing the vibrations at both ends, regardless of which vibration mode is dominant.

  In this configuration, the installation work of the tuned mass damper is limited to the side of the rail and does not reach between the rails. Therefore, the work of installing the tuned mass damper can be performed without stopping the train operation. .

  The tuned mass damper can be installed in any sleeper among the multiple sleepers arranged in a row.For example, it can be installed in all sleepers. This is likely to occur where Therefore, if a sleeper is installed only in such a place, a greater effect can be obtained with a small cost.

  For example, a part where a large impact is applied includes a joint between rails such as a fastening part and a welded part and a part where the structure of the roadbed changes, for example, a structure boundary in a bridge.

The whole sectional view of the sleeper damping structure concerning this embodiment. The whole perspective view. The conceptual diagram explaining the effect | action of the sleeper damping structure which concerns on this embodiment. The conceptual diagram explaining the effect | action of the sleeper damping structure which concerns on a modification.

  Embodiments of a sleeper damping structure according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is an overall cross-sectional view showing a sleeper damping structure according to the present embodiment. As shown in the figure, the sleeper damping structure 1 according to this embodiment includes a road bed 4 composed of a ballast 3 stacked in a trapezoidal cross section on a roadbed 2, and a road bed 4 near the top of the road bed. It is applied to a ballast track 7 comprising a plurality of sleepers 5 arranged in a row along the material axis direction, and rails 6 and 6 laid on the sleepers. Tuned mass dampers 8 and 8 are installed.

  FIG. 2 is an overall perspective view showing the sleeper damping structure 1. As shown in the figure, the tuned mass damper 8 is configured by laminating a steel sheet 21 as a mass body and a rubber sheet 22 as an elastic body that supports the mass body in a freely vibrating manner. The upper and lower ends of the sleeper 5 are respectively installed on the upper surfaces of the sleepers 5 so that the rubber sheet 22 faces downward.

  The steel plate 21 is composed of a rectangular plate, and its mass is adjusted to, for example, several percent of the sleeper 5. Here, the steel plate 21 can be configured as a mass body having a sufficient mass at a reasonable cost by making itself a laminated structure.

  The rubber sheet 22 is formed of a rectangular sheet similarly to the steel plate 21 and has weather resistance and the like so that the steel plate 21 as a mass body can be vibrated in the vertical direction (vertical direction) at a separately determined natural frequency. The material is appropriately determined in consideration. Here, the rubber sheet 22 can be configured as an elastic body having a required restoring force characteristic at a reasonable cost by making itself a laminated structure.

  The steel plate 21 and the rubber sheet 22 are firmly fixed with an adhesive or the like so as not to be separated from each other by vibration, and the rubber sheet 22 is prevented from being detached from the sleeper 5 by the vibration. For example, it is preferable to firmly connect to the sleeper 5 via a base plate (not shown).

  The tuned mass damper 8 has a natural frequency that substantially matches the target frequency, with the frequency corresponding to the vibration that causes the subsidence of the road bed 4 among the vibrations generated by the sleeper 5 during train travel. As described above, the mass of the steel sheet 21 and the rigidity of the rubber sheet 22 are determined, and if the vibration at the target frequency is in the vertical direction, the steel sheet 21 is vibrated with the axial rigidity of the rubber sheet 22, If the vibration at the target frequency is in the horizontal direction, the steel sheet 21 is vibrated with the shear rigidity of the rubber sheet 22. What is necessary is just to adjust the axial direction rigidity and shear rigidity of the rubber sheet 22 to a desired magnitude | size by adjusting the thickness and area suitably.

  The target frequency can be obtained by modeling the sleeper 5 together with the rail 6 and the road bed 4 as necessary, and performing eigenvalue analysis on the vibration model. The natural frequency corresponding to the bending mode around the horizontal axis or around the vertical axis where both ends of the sleeper 5 are opposite in phase to the center can be set as the target frequency.

  In the sleeper damping structure 1 according to the present embodiment, the tuned mass dampers 8 and 8 are installed on the sleeper 5 placed in the vicinity of the top end of the road bed 4 made of the ballast 3, and the tuned mass damper has a unique characteristic. The frequency is substantially matched with the target frequency described above.

  In this way, the vibration that causes the subsidence of the bed bed 4 among the vibrations of the sleeper 5 caused by the train traveling is quickly converged by the tuned mass damper 8, and from the sleeper 5 to the bed bed 4 as the vibration converges. The transmitted kinetic energy is also reduced.

  As described above, according to the sleeper damping structure 1 according to this embodiment, the vibration of the sleeper 5 is converged by the tuned mass damper 8, and the kinetic energy transmitted from the sleeper 5 to the road bed 4 is also reduced. Therefore, the ballast 3 is prevented from being damaged due to the loading of the dynamic load from the sleeper 5 to the road bed 4, and thus the road bed 4 can be prevented from sinking.

  Moreover, according to the sleeper damping structure 1 according to the present embodiment, since the tuned mass damper 8 is simply attached to the sleeper 5, simple construction is sufficient and the influence on the train operation can be minimized. it can.

  Moreover, according to the sleeper damping structure 1 according to the present embodiment, the tuning mass dampers 8 are attached to the vicinity of both ends of the sleeper 5, respectively, so that the vibration of the sleeper 5 causing the subsidence of the road bed 4 is reliably ensured. It becomes possible to suppress.

  That is, as a result of performing eigenvalue analysis on the vibration model of the sleeper 5 and creating a test body of the sleeper 5 and conducting an excitation test, the sleeper is regarded as vibration that may cause subsidence of the road bed 4. In addition to the rigid body mode in which the whole 5 vibrates (6 degrees of freedom), as shown in FIG. 3, the bending mode around the horizontal axis in which both ends of the sleeper 5 are in opposite phase to the center ((a), coordinate axis 2), and it was found that a total of eight vibration modes of the bending mode around the vertical axis where both ends of sleeper 5 are opposite in phase to the center (Fig. (B), ibid) appear at low order. .

  On the other hand, these vibration modes have a mode shape in which the amplitude is large at both ends of the sleeper 5 except for the torsion mode around the material axis of the sleeper 5.

  Therefore, even if any of these vibration modes is specified as the vibration that causes the subsidence of the road bed 4, if the amplitude at both ends of the sleeper 5 is suppressed, the vibration that causes the subsidence of the road bed 4 is ensured. Can be suppressed.

  Further, according to the sleeper damping structure 1 according to the present embodiment, the installation work of the tuned mass dampers 8 and 8 remains outside the rails 6 and 6 and does not extend between the rails 6 and 6. Therefore, it is easy to apply to the existing ballast track 7, and it is possible to perform the installation work of the tuned mass damper 8 without stopping the train operation.

  In the present embodiment, the target frequency is obtained by eigenvalue analysis, but instead, it is obtained by actually measuring vibrations during train travel that occur in sleepers and frequency-analyzing the time history vibration data. It doesn't matter.

  In the present embodiment, an arbitrary frequency is assumed as the target frequency. However, as shown in FIG. 4A, a non-uniform load acts on the road bed 4 over the bottom surface of the sleeper 5, and this damages the ballast 3. In the case that causes the above, the natural frequency corresponding to the bending mode around the horizontal axis in which both ends of the sleeper 5 vibrate up and down with the opposite phase to the center may be set as the target frequency.

  According to such a configuration, the vibration of the sleeper 5 in the vibration mode described above is suppressed by the tuning mass damper 8, so that the dynamic load acting on the road bed 4 from the sleeper 5 is as shown in FIG. 4 (b). It becomes possible to prevent the ballast 3 from being damaged due to a change to a uniform state and thus due to a non-uniform dynamic load.

  Although not particularly mentioned in the present embodiment, the subsidence of the bed is likely to occur at a place where a large impact is applied. Based on this, if the tuned mass damper 8 is limited to the sleepers 5 arranged in the vicinity of the part where the joints between the rails or the structure of the roadbed change, the roadbed can be installed even at a small cost. 4 can be efficiently prevented.

DESCRIPTION OF SYMBOLS 1 Damping structure of sleeper 2 Subbase 3 Ballast 4 Road bed 5 Sleeper 6 Rail 7 Ballast track 8 Tuning mass damper 21 Steel plate (mass body)
22 Rubber sheet (elastic body)

Claims (7)

A tuned mass damper is installed in a sleeper placed near the top of a road bed made of ballast. damping of sleepers almost Rukoto match, characterized in that vibration of the sleepers is configured to be constrained to the target frequency to frequency as a target frequency corresponding to the vibration that causes. The tuned mass damper is formed by laminating a steel plate as a mass body and a rubber sheet as an elastic body that supports the mass body in a freely vibrating manner, and the natural frequency substantially matches the target frequency. The sleeper damping structure according to claim 1, wherein the mass of the steel sheet and the rigidity of the rubber sheet are defined as described above. The sleeper damping structure according to claim 1 or 2 , wherein the target frequency is obtained by actually measuring a vibration during train travel that occurs in the sleeper and performing frequency analysis on the time history vibration data. The sleeper damping structure according to claim 1 or 2 , wherein the target frequency is obtained by performing eigenvalue analysis on the vibration model of the sleeper. The sleeper damping structure according to claim 4 , wherein the target frequency is a natural frequency corresponding to a bending mode around a horizontal axis in which both ends of the sleeper are opposite in phase to the center. The sleeper damping structure according to claim 1 or 2, wherein the tuned mass damper is attached in the vicinity of both ends of the sleeper. The sleeper damping structure according to claim 1 or 2 , wherein the tuned mass damper is installed in a sleeper disposed in the vicinity of a portion of the sleeper where a joint between rails or a structure of a roadbed changes.

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