CN113089467A

CN113089467A - Large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation traffic

Info

Publication number: CN113089467A
Application number: CN202110488579.0A
Authority: CN
Inventors: 伍卫凡; 王健; 胡叙洪; 徐平伟
Original assignee: China Railway Design Corp
Current assignee: China Railway Design Corp
Priority date: 2021-05-06
Filing date: 2021-05-06
Publication date: 2021-07-09

Abstract

The invention discloses a large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation traffic, which comprises a front end track beam, a plurality of middle track beams and a rear end track beam, wherein the front end track beam, the middle track beams and the rear end track beam are sequentially arranged; the lower part of the middle track beam is connected with the main bridge through a movable support; the front end track beam, the middle track beam and the rear end track beam are connected in series through elastic devices; the front end of the front end track beam is connected with the approach bridge through a fixed support, and the tail end of the rear end track beam is connected with the main bridge through a fixed support. The large-span bridge has the beneficial effects that as the elastic device and the movable support are arranged between the track beams of the main bridge, the large displacement of the beam end of the large-span bridge, which is generated by the temperature change, can be converted into a plurality of uniform small displacements between the track beams in the telescopic structure, so that the problem of the over-limit of the stator clearance is solved; meanwhile, the rail beams have good force transmission performance, and the longitudinal stability and the displacement consistency of the telescopic structure can be ensured.

Description

Large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation traffic

Technical Field

The invention belongs to the field of magnetic levitation transportation, and particularly relates to a large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation transportation.

Background

The high-speed magnetic suspension transportation system is used as a point-to-point large-capacity transportation tool, has various advantages of high speed, safety, comfort, energy conservation, environmental protection and the like, can compete and cooperate with high-speed rail and civil aviation, mutually promotes, fills up the blank of the operation speed of a three-dimensional transportation system, brings certain challenges to the development of the traditional transportation mode, forms a new market pattern, and becomes a symbolic project for promoting the construction of the strong country of transportation.

The high-speed magnetic suspension traffic system drives the train to run at high speed by forming a linear motor by the stators with certain length arranged on two sides of the track beam and the rotor on the train, and has strict requirements on the stator clearance. The high-speed magnetic levitation is more suitable for long-distance long and large trunk transportation due to the speed advantage, but is influenced by factors such as natural conditions and the like, and inevitably adopts a large-span bridge structure to span large rivers. Influenced by the temperature, the flexible volume of large-span bridge beam-ends is big, and the beam seam value is difficult to satisfy the stator clearance requirement of arranging, need reduce the stator clearance through setting up special flexible compensation arrangement.

The large-span bridge among the wheel-rail railway faces the big problem of bridge flexible displacement equally, often needs to solve through setting up flexible regulator, and its principle is to reduce the longitudinal interaction between bridge and the track, releases the track displacement that the bridge warp and arouse. The gap requirement of the high-speed magnetic suspension stator is strict, and the gap is more difficult to control due to the fact that the stator displacement is released, so that the problem cannot be solved by adopting a railway telescopic regulator structure.

Disclosure of Invention

The invention aims to solve the technical problem of providing a beam end telescopic structure of a long-span bridge, which meets the requirement of stator arrangement gaps, ensures the longitudinal stability and the displacement consistency of the telescopic structure and is suitable for high-speed magnetic suspension traffic.

The invention adopts the technical scheme that the large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation traffic comprises a front end track beam, a plurality of middle track beams and a rear end track beam which are sequentially arranged; the lower part of the middle track beam is connected with the main bridge through a movable support; the front end track beam, the middle track beam and the rear end track beam are connected in series through elastic devices; the front end of the front end track beam is connected with the approach bridge through a fixed support, and the tail end of the rear end track beam is connected with the main bridge through a fixed support.

The lengths of the front end track beam, the rear end track beam and the middle track beams are integral multiples of the length of the stator.

The front end track beam spans a girder seam formed between the approach bridge and the main bridge, a fixed support at one side of the front end track beam is arranged on the approach bridge, and a longitudinal movable support at the other side of the front end track beam is arranged on the main bridge.

The middle track beam and the rear track beam are arranged in the same telescopic area of the main bridge, and the middle track beams are connected with the main bridge by adopting a longitudinal movable support; the side of the rear end track beam close to the girder seam is connected with the main bridge by adopting a longitudinal movable support, and the side far away from the girder seam is connected with the main bridge by adopting a fixed support.

The elastic device is a rubber or steel spring with high elasticity and high rigidity.

The elastic device is connected with the embedded sleeve at the end part of the track beam into a whole through a high-strength bolt.

The invention has the advantages that as the elastic device and the movable support are arranged between the track beams of the main bridge, the large displacement of the beam end of the large-span bridge, which is generated by the temperature change, can be converted into a plurality of uniform small displacements between the track beams in the telescopic structure, thereby solving the problem of the over-limit of the stator clearance; meanwhile, the rail beams have good force transmission performance, and the longitudinal stability and the displacement consistency of the telescopic structure can be ensured.

Drawings

FIG. 1 is a schematic view of a beam end telescopic structure of a long-span bridge of the invention;

FIG. 2 is a schematic diagram of the beam-end telescopic structure of the long-span bridge according to the present invention after displacement (elongation);

FIG. 3 is a schematic diagram of the beam-end telescopic structure of the long-span bridge according to the present invention after displacement (shortening);

fig. 4 is a schematic view of the installation of the elastic device in the beam end telescopic structure of the large-span bridge of the invention.

In the figure:

1. bridge movable support 2, bridge fixed support 3, approach bridge 4 and main bridge

5. Movable support 6, fixed support 7, front end track beam 8, track beam

9. The rear end track beam 10, the elastic device 11 and the girder seam.

Detailed Description

The invention is described in further detail below with reference to the following figures and detailed description:

as shown in fig. 1 to 4, the large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation traffic of the present invention includes a bridge approach and a main bridge, which are respectively provided with a bridge movable support 1 and a bridge fixed support 2, and the bridge beam end telescopic structure includes a front end track beam 7, a plurality of middle track beams 8 and a rear end track beam 9, which are sequentially arranged; the lower parts of the middle track beams 8 are connected with the main bridge 4 through movable supports 5; the front end track beam 7, the middle track beam 8 and the rear end track beam 9 are connected in series through elastic devices 10, and the longitudinal change range of beam gaps among the track beams meets the requirement of stator gaps; the front end of the front end track beam 7 is connected with the approach bridge 3 through a fixed support 6, and the tail end of the rear end track beam 9 is connected with the main bridge 4 through the fixed support 6.

The front end rail beam 7 firstly spans a girder seam 11 formed between the approach bridge 3 and the main bridge 4, a fixed support 6 on one side of the front end rail beam 7 is arranged on the approach bridge 3, and a longitudinal movable support 5 on the other side of the front end rail beam 7 is arranged on the main bridge. The end position of the middle track beam 8 and the rear end track beam 9 are arranged in the same telescopic area range of the main bridge 4, and the middle track beams 8 are connected with the main bridge 4 by adopting longitudinal movable supports 5; the side of the rear end track beam 9 close to the girder seam 11 is connected with the main bridge 4 by adopting a longitudinal movable support 5, and the side far away from the girder seam 11 is connected with the main bridge 4 by adopting a fixed support 6. The number of the middle track beams 8 is comprehensively determined according to the length of the telescopic area of the main bridge 4, the requirement of the stator clearance and other factors.

The lengths of the front end track beam 7, the rear end track beam 9 and the middle track beams 8 are integral multiples of the length of the stator, and the lengths are comprehensively determined according to the length of a telescopic area of the main bridge 4, the distance between the fixed support 6 of the rear end track beam 9 and the fixed support of the main bridge 4, the requirement of the stator clearance and other factors.

The elastic device 10 is a rubber or steel spring with high elasticity and high rigidity, and the elastic rigidity is comprehensively determined according to the factors such as the length of the telescopic area of the main bridge 4, the stator gap requirement, the structural stress and the like. Elastic device can realize 6 displacement homodisperses of both ends track roof beam fixing support to each track roof beam within a definite time, avoids the stator clearance transfinite, can transmit train longitudinal force to both ends fixing support 6 simultaneously. The elastic device 10 is connected with the embedded sleeve at the end part of the track beam through a high-strength bolt, and the installation is convenient.

As shown in fig. 2 and 3, when the approach bridge 3 and the main bridge 4 are subjected to extension or contraction deformation under the influence of temperature, the fixed supports 6 at the two ends of the beam-end telescopic structure generate the same displacement along with the approach bridge 3 and the main bridge 4, the displacement between the two fixed supports 6 is increased or shortened, the rest movable supports 5 freely slide on the main bridge 4 along the longitudinal direction, and the elastic device 10 uniformly disperses the displacement change between the two fixed supports 6 to the space between the track beams, so that the stator clearance is prevented from exceeding the limit.

Example (b):

taking main bridge temperature span 200m as an example, designing a beam joint with 200mm, and taking the maximum temperature variation amplitude of the beam body affected by the outside to be +/-20 ℃, so that the maximum expansion amount of the main bridge end affected by the temperature is +/-40 mm, the variation range of the beam joint is 160 mm-240 mm, the requirement of 90-100 mm of stator clearance at the main bridge and the bridge approach gap position cannot be met, and a beam end expansion structure needs to be arranged.

In the embodiment, the rail beams of the beam-end telescopic structure are longitudinally connected by steel springs, the steel springs are installed by high-strength bolts and sleeves embedded at the end parts of the rail beams, and the stiffness value of the steel springs is determined comprehensively by comprehensively considering the number of the middle rail beams, the stress requirements of main bridges and approach bridges, the requirements of the rail beams and the like. The larger the rigidity of the steel spring is, the larger the temperature force transmitted to the main bridge and the approach bridge by the telescopic structure is, and the more adverse to the stress of the foundation structure is. In actual engineering, the longitudinal movable support of the track beam does not completely move, certain frictional resistance still exists, and the deformation inconsistency among the middle track beams can be caused when the rigidity of the steel spring is too small, and large displacement is generated under the braking (starting) action of a train.

In this example, the lengths of the front end track beam, the rear end track beam and the middle track beams are 3.096m (3 times of the length of the stator), the standard beam gap between the track beams is 95mm, and the allowable variation range of the beam gap between the track beams of the beam end telescopic structure is +/-5 mm, so that the number of the middle track beams is at least 7 holes.

In the example, the number of the middle track beams is 7, the longitudinal rigidity of the steel spring between the track beams is 15kN/mm, the maximum acting force transmitted to the main bridge and the approach bridge by the telescopic structure under the action of temperature is 75kN, and the acting force is used as an additional force to detect and calculate the bridge structure.

Meanwhile, according to relevant regulations, the change of the width of the rail beam seam caused by braking and starting of the train is less than 10 mm. Referring to relevant specifications, the braking (starting) load of the high-speed maglev train is 5.0kN/m, the maximum change of the beam gap of the middle track beam is 8.26mm through calculation, and the requirements are met.

It should be noted that the above-mentioned embodiments are only for illustrating the technical concept and features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the present invention and implement the present invention, and not to limit the protection scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation traffic is characterized by comprising a front end track beam (7), a plurality of middle track beams (8) and a rear end track beam (9) which are sequentially arranged; the lower parts of the middle track beams (8) are connected with the main bridge (4) through movable supports (5); the front end track beam (7), the middle track beam (8) and the rear end track beam (9) are connected in series through elastic devices (10); the front end of the front end track beam (7) is connected with the approach bridge (3) through a fixed support (6), and the tail end of the rear end track beam (9) is connected with the main bridge (4) through the fixed support (6).

2. The large-span bridge beam end expansion structure suitable for high-speed magnetic suspension traffic of claim 1, wherein the lengths of the front end track beam (7), the rear end track beam (9) and the middle track beams (8) are integral multiples of the length of the stator.

3. The large-span bridge beam end telescopic structure applicable to high-speed magnetic suspension traffic is characterized in that the front end track beam (7) spans a girder seam (11) formed between the approach bridge (3) and the main bridge (4), a fixed support (6) on one side of the front end track beam (7) is arranged on the approach bridge (3), and a longitudinally movable support (5) on the other side of the front end track beam (7) is arranged on the main bridge.

4. The large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation transportation according to claim 1, wherein the middle track beam (8) and the rear track beam (9) are arranged in the same telescopic area of the main bridge (4), and the middle track beams (8) are connected with the main bridge (4) through longitudinal movable supports (5); the side of the rear end track beam (9) close to the girder seam (11) is connected with the main bridge (4) by adopting a longitudinal movable support (5), and the side far away from the girder seam (11) is connected with the main bridge (4) by adopting a fixed support (6).

5. The large-span bridge beam end expansion structure suitable for high-speed magnetic levitation transportation according to claim 1, wherein the elastic device (10) is a high-elasticity and high-rigidity rubber or steel spring.

6. The large-span bridge beam end telescopic structure suitable for high-speed magnetic levitation traffic as claimed in any one of claims 1 or 5, wherein the elastic device (10) is connected with the embedded sleeve at the end of the track beam into a whole through a high-strength bolt.