A track surface smoothness maintaining structure for urban rail floating slab track bed

Abstract

The present invention discloses a track surface smoothness maintaining structure for a floating plate roadbed of an urban railroad, comprising a steel spring floating plate section, two pre-arch transition sections and two non-vibration reduction sections, the track on the steel spring floating plate section is the first track, the track on each pre-arch transition section is the second track, and the track on each non-vibration reduction section is the third track; the track surface of the first track is higher than the track surface of each third track; the second track is connected to the under-track foundation through a plurality of second fasteners; along the direction from the third track to the first track, the height of these second fasteners gradually increases and the stiffness gradually decreases, so that the vertical distance between the wheel center and the track surface smoothness reference line is maintained within a set range. The present invention can improve the track surface smoothness of the floating plate roadbed section, improve the stability and safety of the train passing through the steel spring floating plate section, thereby adapting to the special vibration reduction requirements of higher speeds, and filling the gap of the special vibration reduction track structure of the urban railroad.

Description

Technical Field

[0001] The invention belongs to the field of track design, and more specifically, relates to a floating slab track bed structure for an urban railroad. Background Art

[0002] The vibration reduction design of rail transit engineering is the key and difficult point of rail system design. Generally speaking, the vibration reduction level is divided into three levels according to the predicted excess amount of environmental impact assessment: medium vibration reduction, high vibration reduction and special vibration reduction. Among them, the special vibration reduction measure adopts steel spring floating plate vibration reduction ballast bed.

[0003] Floating slab tracks are widely used in traditional urban rail transit subway projects, and the design and technical solutions are mature and reliable, but the vehicle operating speed does not exceed 100 km / h and the vehicle axle weight does not exceed 16H.

[0004] With the rapid development of urban rail transit, the maximum operating speed of trains has reached 100 km / h ~160 km / h, and the vehicle axle weight has been adopted as 17H, which is significantly higher than the operating speed of traditional urban rail transit vehicles and the axle weight has increased, which puts higher requirements on the track surface smoothness of the floating slab track bed.

[0005] Patent CN110700023A proposes a steel spring floating plate integral ballast based on track engineering. In this solution, there is no effective transition measure between the steel spring floating plate ballast and the non-vibration-damping section. When the train passes through the boundary between the floating plate ballast and the non-vibration-damping ballast, due to the change in stiffness, a large unevenness will be formed on the top surface of the rail, resulting in the phenomenon of train jumping when the train passes, which affects the operation safety.

[0006] Patent CN203475237U proposes a prefabricated steel spring floating plate, which transmits the lateral force between the floating plates through the end bosses, and the floating plates are connected by hinges. This solution uses a built-in hinge at the end to force the uneven track surface between the floating plates and between the floating plates and the general track bed. The vertical force at the transition point of the floating plate in this solution is provided by the hinge, which is not friendly to the force of the hinge device of the floating plate and poses a safety hazard. The end hinge method makes it difficult to easily remove the prefabricated floating plate when a disease occurs. Multiple floating plates need to be lifted at the same time to achieve replacement and maintenance of the floating plates, which is a large workload. Summary of the invention

[0007] In response to the above defects or improvement needs of the prior art, the present invention provides a track surface smoothness maintaining structure for the floating slab track bed of urban railways, which can improve the track surface smoothness of the floating slab track bed section and adapt to special vibration reduction requirements under higher speed conditions.

[0008] To achieve the above object, according to one aspect of the present invention, a track surface smoothness maintaining structure for a floating slab track bed of an urban railway is provided, characterized in that it comprises a steel spring floating slab section, two pre-arch transition sections and two non-vibration reduction sections, wherein:

[0009] The track on the steel spring floating plate section is the first track, the track on each section of the pre-arch transition section is the second track, and the track on each section of the non-vibration reduction section is the third track. Each end of the first track is connected to one end of a section of the third track through a section of the second track.

[0010] The first track and each of the third tracks are arranged horizontally, and the track surfaces of the two third tracks have the same height;

[0011] The track surface of the first track is higher than the track surface of each section of the third track and the height difference between them is the pre-camber value H of the first track;

[0012] The first track is connected to the floating plate through a plurality of first fasteners, the second track is connected to the foundation under the track through a plurality of second fasteners, and the third track is connected to the foundation under the track through a plurality of third fasteners;

[0013] Along the direction from the third track to the first track, the height of these second fasteners gradually increases and the stiffness gradually decreases, so that when the train travels on the first track, the second track and the third track, the vertical distance between the center of the wheel and the rail surface smoothness reference line is maintained within a set range; wherein the rail surface smoothness reference line is a set horizontal reference line.

[0014] Preferably, a recommended setting value for the pre-arch value of the first track is obtained through simulation calculation of actual parameters of the train and the floating plate; and adjustments are made to the implementation effect of the pre-arch value of the first track through on-site monitoring and test evaluation to compensate for the deviation of the simulation calculation, so that the pre-arch value of the first track effectively maintains the smoothness of the track surface when the train passes through the steel spring floating plate section.

[0015] Preferably, before fine-tuning the laying of the first track, based on the track structure of the line and the actual parameters of the operating train, the vertical displacement of the first track when the train passes through the steel spring floating plate section is simulated and calculated, and the pre-arch value of the first track is obtained by the vertical displacement of the first track.

[0016] Preferably, the pre-camber value of the first track is determined by using wheel-rail dynamics according to the train axle weight, train operating speed and floating plate stiffness.

[0017] Preferably, all of the first fasteners have the same stiffness, and all of the third fasteners have the same stiffness.

[0018] Preferably, the horizontal length L of each pre-arch transition section is determined according to the train running speed.

[0019] Preferably, the horizontal length L of each pre-arch transition section is not less than 12 m.

[0020] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0021] 1) Through the implementation of the present invention, the track surface smoothness of the floating plate track section can be improved, and the stability and safety of the train passing through the steel spring floating plate section can be improved, so as to meet the special vibration reduction requirements of higher speeds (100 km / h ~ 160 km / h), fill the gap in the special vibration reduction track structure of the urban rail, and can also be used on intercity, subway and other lines.

[0022] 2) The recommended setting value of the pre-camber value is obtained through simulation calculation of the actual parameters of the train and the floating plate. The implementation effect of the pre-camber value is adjusted through on-site monitoring and test evaluation to compensate for the deviation of the simulation calculation, so that the pre-camber value can effectively maintain the smoothness of the track surface when the train passes through the steel spring floating plate section.

[0023] 3) Through the design of the above-mentioned pre-arch value, the track surface line shape of the traditional steel spring floating plate section is optimized, so that when the train passes through the steel spring floating plate section, the track can always remain near the track surface smoothness baseline after the vertical displacement under the action of the train load. The track surface smoothness of the floating plate roadbed is improved when the train passes, thereby improving the smoothness of train operation, reducing track corrugation, extending service life, and reducing maintenance workload.

[0024] 4) A pre-arch transition section is set between the non-vibration-damping section and the steel spring floating plate section to achieve a smooth transition of the track structure stiffness and pre-arch value.

[0025] 5) When the train runs in the pre-arch transition section and the steel spring floating plate section, due to the existence of the pre-arch value, the vertical displacement of the track caused by the train load will return to the vicinity of the track surface smoothness baseline, thereby realizing the technology of maintaining the track surface smoothness in the steel spring floating plate section. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the present invention when there is no train passing by;

[0027] Figure 2 It is a structural diagram of a train passing through the pre-arch transition section;

[0028] Figure 3 It is a schematic diagram of the structure when the train passes through the steel spring floating plate section. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] like Figure 1~Figure 3 As shown, a track surface smoothness maintaining structure for a floating plate track bed of an urban railway includes a steel spring floating plate section 1, two pre-arch transition sections 2 and two non-vibration reduction sections 3, and they jointly undertake the train running track, wherein:

[0031] The track of the train running track on the steel spring floating plate section 1 is the first track 11, the track of the train running track on each section of the pre-arch transition section 2 is the second track 21, and the track of the train running track on each section of the non-vibration reduction section 3 is the third track 31. Each end of the first track 11 is connected to one end of a section of the third track 31 through a section of the second track 21. It can be seen from the figure that from left to right, the track connection is smoothly the third track 31-second track 21-first track 11-second track 21-third track 31, and they are connected in sequence. The steel spring floating plate section 1 is between the two sections of the pre-arch transition section 2, and the two sections of the pre-arch transition section 2 are between the two sections of the non-vibration reduction section 3. The two second tracks 21 are symmetrically arranged at the left and right ends of the first track 11, and the two third tracks 31 are also symmetrically arranged.

[0032] The first rail 11 and each of the third rails 31 are arranged horizontally, and the rail surfaces (rail surfaces refer to the upper surface, the same below) of the two third rails 31 are at the same height;

[0033] The track surface of the first track 11 is higher than the track surface of each section of the third track 31 and their height difference H serves as the pre-arch value of the first track; "pre-arch" can be understood as a "height" that is pre-raised relative to the track surface of the third track. Within the range of the steel spring floating plate section 1, the pre-arch value is preset when the floating plate of the steel spring floating plate section 1 is lifted.

[0034] The first track 11 is connected to the floating plate through a plurality of first fasteners 12, the second track 21 is connected to the track foundation through a plurality of second fasteners 22, and the third track 31 is connected to the track foundation through a plurality of third fasteners 32; the floating plate is installed on the lower foundation of the floating plate through an elastic vibration isolator 13, the track foundation is connected to the lower foundation of the floating plate, and together they serve as a foundation to support the upper structure, and the first track 11, the two second tracks 21 and the two third tracks 31 are connected to form a train running track

[0035] Along the direction from the third track 31 to the first track 11, the height of these second fasteners 22 gradually increases (the gradual change of the pre-arch value in the pre-arch transition section is achieved by raising the second fasteners 22, and the height of the second fasteners 22 is adjusted by raising the pad, and the height gradually increases), and the stiffness gradually decreases (the stiffness of the second fasteners 22 themselves is adjusted by the model (performance) of the elastic pad and the elastic bar, and the stiffness parameter change of the second fasteners 22 can be set to uniform change first. According to the number of second fasteners 22 within the range of the second track 21, and the stiffness difference between the first fasteners 12 of the first track 11 and the third fasteners 32 of the third track 31, the decreasing value of the stiffness of adjacent second fasteners 22 can be calculated, and it can be verified and adjusted according to the wheel-rail dynamics at a later stage. After the stiffness of each fastener and the pad is determined, it is still necessary to pass Wheel-rail dynamics verifies its driving safety. The verification technology of wheel-rail dynamics is mature and will not be repeated here) so that when the train is running on the first rail 11, the second rail 21 and the third rail 31, the vertical distance between the wheel center and the track surface smoothness reference line 4 is maintained within a set range; wherein, the track surface smoothness reference line 4 is a set horizontal reference line, and the vertical displacement of the third rail 31 is small and can be ignored. Therefore, the track surface smoothness reference line 4 can be set to the track surface of the third rail 31. In the pre-arch transition section 2, the pre-arch value of the second rail 21 (the distance from the track surface of the second rail 21 to the track surface of the third rail 31, one end of the second rail 21 is connected to the third rail 31 and the other end is connected to the first rail 11, so the pre-arch value of the second rail 21 is greater than or equal to 0 and less than or equal to H.

[0036] Furthermore, all the first fasteners 12 have the same stiffness, and they use a uniform fastener stiffness; all the third fasteners 32 have the same stiffness, and they use a uniform fastener stiffness. The first fasteners 12 are all non-vibration-damping fasteners (relative to vibration-damping fasteners), and the second fasteners 22 and the third fasteners 32 can be either vibration-damping fasteners or non-vibration-damping fasteners.

[0037] Furthermore, a recommended setting value of the pre-arch value of the first track 11 is obtained through simulation calculation of actual parameters of the train and the floating plate; and adjustments are made to the implementation effect of the pre-arch value of the first track 11 through on-site monitoring and test evaluation to compensate for the deviation of the simulation calculation, so that the pre-arch value of the first track 11 can effectively maintain the smoothness of the track surface when the train passes through the steel spring floating plate section, that is, the pre-arch value of the first track 11 can be obtained in advance through simulation calculation, and can be continuously adjusted and optimized through subsequent on-site monitoring to obtain a more appropriate value.

[0038] Furthermore, before the first rail 11 is laid and fine-tuned, the vertical displacement of the first rail 11 when the train passes through the steel spring floating plate section is simulated and calculated based on the track structure of the line and the actual parameters of the operating train, and the pre-arch value H of the first rail 11 is obtained by the vertical displacement of the first rail 11.

[0039] Furthermore, the pre-camber value of the first track 11 is determined by simulation and calculation based on the train axle weight, train operating speed and floating plate stiffness using wheel-rail dynamics theory and methods.

[0040] Furthermore, the horizontal length L of each pre-arch transition section 2 is determined according to the driving speed, and the horizontal length L of each pre-arch transition section 2 is generally not less than 12m, so as to meet the smooth running of various types of trains and realize the smooth transition from the non-vibration-damping section 3 to the steel spring floating plate section 1.

[0041] The present invention provides a track surface smoothness maintenance technology for a floating plate track bed. When a train passes through the floating plate track bed, the track structure can maintain a smooth track line shape, thereby improving the stability and safety of train operation to meet the requirements of higher speed lines for floating plate track structures. The present invention sets a pre-arch transition section between the non-vibration-damping section of the floating plate track bed and the steel spring floating plate section, so that the track surface can maintain a high level of smoothness when the train passes through, improves the stability and safety of train operation, and creates conditions for the application of floating plate tracks on higher lines. The present invention optimizes the original track surface line shape of the steel spring floating plate section. When the train passes through the steel spring floating plate section, after the track is vertically displaced due to the train load, the track surface line shape under the actual train always maintains a good level of smoothness.

[0042] The present invention sets a pre-arch transition section at the end of the non-vibration damping section, and the pre-arch of the pre-arch transition section is achieved by adjusting the height of the fasteners. Within the range of the length L of the pre-arch transition section, the pre-arch value is steadily increased from 0 to the height H calculated above by adjusting the height of the fasteners. The rail surface of the steel spring floating plate section follows the end of the rail surface of the pre-arch transition section, that is, the rail surface height of the first track 11 of the steel spring floating plate section has a height difference of a pre-arch value H compared with the non-vibration damping section. When leaving the steel spring floating plate section again, it passes through a pre-arch transition section again, and the pre-arch value is steadily reduced from H to 0. The non-vibration damping section follows the pre-arch transition section, and the above-mentioned pre-arch value 0 is continued in the non-vibration damping section.

[0043] Fasteners with gradually changing stiffness and height are used in the pre-arch transition section. The fastener stiffness smoothly transitions from the stiffness of the first fastener 12 corresponding to the non-vibration-damping section to the overall stiffness of the track structure corresponding to the steel spring floating plate section, thereby achieving smooth transition of the track structure stiffness, so that the track structure stiffness remains stable and uniform when transitioning from the non-vibration-damping section to the steel spring floating plate section.

[0044] After the train is put into operation, the effect of setting the pre-arch value is evaluated through on-site monitoring and testing, and the pre-arch value is further adjusted to improve the deviation of the simulation calculation.

[0045] By setting the pre-arch value in the pre-arch transition section and the steel spring floating plate section, the track surface line shape is always kept near the track surface smoothness reference line 4 when the train passes, so that the track surface smoothness of the floating plate track bed is maintained.

[0046] The control of the basic line shape of the lower part of the track remains unchanged in the traditional way and will not be repeated here.

[0047] When the train passes through a section without vibration reduction, under the action of the train load, the rail surface of the third track pressed down by the train can be maintained near the rail surface smoothness reference line 4 (at this time, the vertical distance between the center line of the train wheel and the rail surface smoothness reference line 4 is within the set range); when the train passes through the pre-arch transition section, through the pre-arch value and the stiffness gradual matching setting of the stiffness, under the action of the train load, the rail surface of the second track pressed down by the train can be maintained near the rail surface smoothness reference line 4; when the train passes through the steel spring floating plate section, through the setting of the pre-arch value H, under the action of the train load, the rail surface of the first track pressed down by the train can be maintained near the rail surface smoothness reference line 4. Through the above process, when the train passes, the track under the train is located near the rail surface smoothness reference line 4, thereby realizing the rail surface smoothness maintenance technology of the steel spring floating plate section.

[0048] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A track surface smoothness maintaining structure for a floating slab track bed of an urban railway, characterized in that: It includes a steel spring floating plate section, two pre-arch transition sections and two non-vibration reduction sections, among which: The track on the steel spring floating plate section is the first track, the track on each section of the pre-arch transition section is the second track, and the track on each section of the non-vibration reduction section is the third track. Each end of the first track is connected to one end of a section of the third track through a section of the second track. The first track and each of the third tracks are arranged horizontally, and the track surfaces of the two third tracks have the same height; The track surface of the first track is higher than the track surface of each section of the third track and the height difference between them is the pre-camber value H of the first track; The first track is connected to the floating plate through a plurality of first fasteners, the second track is connected to the foundation under the track through a plurality of second fasteners, and the third track is connected to the foundation under the track through a plurality of third fasteners; Along the direction from the third track to the first track, the height of these second fasteners gradually increases and the stiffness gradually decreases, so that when the train travels on the first track, the second track and the third track, the vertical distance between the center of the wheel and the rail surface smoothness reference line is maintained within a set range; wherein the rail surface smoothness reference line is a set horizontal reference line.

2. A rail surface smoothness maintaining structure for a floating slab track bed of an urban railway according to claim 1, characterized in that: The recommended setting value of the pre-arch value of the first track is obtained through simulation calculation of the actual parameters of the train and the floating plate. The implementation effect of the pre-arch value of the first track is adjusted through on-site monitoring and test evaluation to compensate for the deviation of the simulation calculation, so that the pre-arch value of the first track can effectively maintain the smoothness of the track surface when the train passes through the steel spring floating plate section.

3. The track surface smoothness maintaining structure for the floating slab track bed of the urban railway according to claim 1, characterized in that: Before fine-tuning the laying of the first track, based on the track structure of the line and the actual parameters of the operating trains, the vertical displacement of the first track when the train passes through the steel spring floating plate section is simulated and calculated, and the pre-arch value of the first track is obtained by the vertical displacement of the first track.

4. The track surface smoothness maintaining structure for the floating slab track bed of the urban railway according to claim 1, characterized in that: The pre-camber value of the first track is determined by wheel-rail dynamics based on the train axle weight, train operating speed and floating slab stiffness.

5. The track surface smoothness maintaining structure for the floating slab track bed of the urban railway according to claim 1, characterized in that: All of the first fasteners have the same stiffness, and all of the third fasteners have the same stiffness.

6. The track surface smoothness maintaining structure for the floating slab track bed of the urban railway according to claim 1, characterized in that: The horizontal length L of each pre-arch transition section is determined according to the train speed.

7. The track surface smoothness maintaining structure for the floating slab track bed of the urban railway according to claim 1, characterized in that: The horizontal length L of each pre-arch transition section is not less than 12m.

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