CN110468676B

CN110468676B - Bridge structure

Info

Publication number: CN110468676B
Application number: CN201910793488.0A
Authority: CN
Inventors: 方根深; 赵林; 葛耀君
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2019-08-26
Filing date: 2019-08-26
Publication date: 2021-08-27
Anticipated expiration: 2039-08-26
Also published as: CN110468676A

Abstract

The invention discloses a bridge structure, which comprises: the device comprises a bridge body, a railing, a rotating shaft for driving the railing to swing relative to the bridge body, a driver and a controller for controlling the driver to drive the rotating shaft to rotate. Above-mentioned bridge structures, under the condition that does not influence structure section overall arrangement, can rock the railing and can have multiple different gestures and the action of rocking of multiple difference, can adjust the gesture and rock the action in real time according to the incoming flow wind characteristic, the surface aerodynamic force change of structure, the structure vibration condition, can improve bridge structures's anti-wind performance high-efficiently. The different postures and the adjustment of the swinging motion of the swinging handrail can realize the active control of the structure aerodynamic performance and can deal with various wind-induced vibration problems of vortex-induced vibration, buffeting, flutter and the like. Above-mentioned bridge structures, the bridge section need not to add other subsidiary pneumatic means, and is very little to the whole change of bridge structures. In addition, the bridge structure can be widely applied to various bridge sections and has strong adaptability.

Description

Bridge structure

Technical Field

The invention belongs to the technical field of bridges, and relates to a bridge structure.

Background

The wind-induced vibration is a key power problem of a large-span flexible bridge and mainly comprises vibration modes such as vortex-induced vibration, flutter, buffeting and the like. Vortex-induced vibration and buffeting are likely to occur at different wind speeds theoretically, and long-term vibration can cause cracks and even fatigue damage to a structure in a service period and directly influence the driving safety and comfort; flutter is a severe vibration mode generated by a bridge structure under high wind speed, and once the violent vibration occurs, the catastrophic damage to the bridge structure can be caused; therefore, controlling the vortex-induced vibration and buffeting amplitude of the bridge structure and improving the flutter critical wind speed are main targets of wind resistance of the large-span bridge.

At present, measures for controlling the wind-induced vibration amplitude of a bridge and improving the flutter stability mainly comprise pneumatic measures, structural measures and mechanical measures. Wherein, the pneumatic measure is mainly to improve the wind resistance of the structure by changing the shape of the cross section of the bridge; the structural measures optimize the dynamic characteristics of the structure by changing the overall arrangement of the structure and coordinating the mass rigidity distribution; mechanical measures control the vibration amplitude by providing additional dampers to dissipate the vibration energy. Wherein, the structural measures have limited contribution to improving the wind resistance of the structure; mechanical measures have high stability but often high cost, and pneumatic measures have the most extensive application due to small influence on the scheme of the main structure body and low cost. The main purpose of the measures is to change the pneumatic load borne by the cross section of the bridge by optimizing the pneumatic appearance of the cross section of the bridge, thereby improving the wind resistance of the bridge structure.

Traditional pneumatic measures are poor in adaptability and universality, the improvement range of the wind resistance of a bridge structure is limited, and most measures cannot improve various wind vibration performances of the bridge structure such as vortex-induced vibration, buffeting and flutter at the same time. Meanwhile, most of the pneumatic measures need to add an auxiliary structure on the surface of the cross section to realize pneumatic control, such as a central stabilizing plate, a flow restraining plate and the like, which can affect the driving vision to a certain extent.

Disclosure of Invention

In order to overcome the defects of the traditional pneumatic measure, a new bridge structure with the pneumatic measure is needed.

A bridge construction comprising:

a bridge body;

the railings are positioned on the two side edges of the bridge body;

the rotating shaft is arranged at the bottom of the railing and is used for driving the railing to swing relative to the bridge body;

the driver is used for driving the rotating shaft to rotate;

the controller is used for controlling the driver to drive the rotating shaft to rotate; the controller is electrically connected with the driver.

Above-mentioned bridge structures, under the condition that does not influence structure section overall arrangement, can rock the railing and can have multiple different gestures and the action of rocking of multiple difference, can adjust the gesture and rock the action in real time according to the incoming flow wind characteristic, the surface aerodynamic force change of structure, the structure vibration condition, can improve bridge structures's anti-wind performance high-efficiently. The different postures and the adjustment of the swinging motion of the swinging handrail can realize the active control of the structure aerodynamic performance and can deal with various wind-induced vibration problems of vortex-induced vibration, buffeting, flutter and the like. Above-mentioned bridge structures, the bridge section need not to add other subsidiary pneumatic means, and is very little to the whole change of bridge structures. In addition, the bridge structure can be widely applied to various bridge sections and has strong adaptability.

Optionally, the bridge construction has an upright mode, a tip-over mode, and a sway mode;

in the erect mode, the balustrade is erected relative to the bridge body;

in the turning-over mode, the railing is attached to the upper surface of the bridge main body;

in the sway mode, the balustrade sways relative to the bridge body.

Optionally, the balustrade comprises a plurality of segmented balustrades arranged at intervals; and each subsection column is correspondingly provided with one rotating shaft.

Optionally, the bridge structure further has a staggered pendulum mode;

in the staggered swing mode, two of the segmented columns perform different swing actions.

Optionally, in the staggered swing mode, the swing frequencies of two of the segmented columns are different;

or, the amplitude of the swing of two segmented columns is different;

alternatively, the phase of the wobble differs for two segmented columns.

Optionally, the sectional rail includes a railing post and a guardrail body fixed between the two adjacent railing posts.

Optionally, the bridge body is a closed box girder structure.

Optionally, the bridge body is a half-open box girder structure.

Optionally, the balustrade is a manhole balustrade.

Optionally, the drive is a motor.

Drawings

Fig. 1 is a schematic cross-sectional view of a bridge structure according to an embodiment of the present invention.

Fig. 2 is a partially enlarged view of a portion a in fig. 1.

Fig. 3 is a schematic view of a handrail structure according to an embodiment of the invention.

Fig. 4 is a partial schematic view of a bridge structure according to an embodiment of the present invention in a vertical mode.

Fig. 5 is a partial schematic view of a bridge structure according to an embodiment of the present invention in a turnover mode.

Fig. 6 is a partial schematic view of a bridge structure according to an embodiment of the invention in a swing mode.

Fig. 7 is a partial schematic view of a bridge structure in a staggered mode according to an embodiment of the present invention.

Fig. 8 is a schematic structural diagram of a bridge section of a bridge structure according to an embodiment of the present invention.

Fig. 9 is a wind tunnel experiment result diagram of a bridge structure according to an embodiment of the present invention.

Fig. 10 is a schematic cross-sectional view of a bridge structure according to another embodiment of the present invention.

Fig. 11 is a schematic structural view of a bridge section of a bridge structure according to another embodiment of the present invention.

Fig. 12 is a wind tunnel experiment result diagram of a bridge structure according to another embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments. It should be understood that the detailed description and specific examples, while indicating the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1-2, a bridge construction 100 according to an embodiment of the present invention includes a bridge body 10, a balustrade 20, a rotary shaft 30, a drive (not shown), and a controller (not shown).

The bridge body 10 is a main structure of the bridge 100. In this embodiment, the bridge body 10 is a closed box girder structure. The closed box girder structure is a structure known in the art, and the detailed structure is not described herein.

Wherein, the balustrade 20 is located at two side edges of the bridge body 10. Unlike the conventional handrail fixed on the bridge body, in the present invention, the handrail 20 can swing with respect to the bridge main body 10, that is, the angle of the dihedral angle between the handrail and the surface of the bridge main body is not limited to 90 degrees, but can be any value from 0 degree to 180 degrees. In the present invention, the balustrade 20 not only plays a role of protection, but also plays a role of suppressing wind-induced vibration when wind exists.

The rotating shaft 30 is disposed at the bottom of the balustrade 20, and thus can be used to drive the balustrade 20 to swing relative to the bridge body 10. That is, the shaft 30 is the axis of the rail 20, and the rail 20 swings about the shaft 30.

The main function of the driver is to drive the rotating shaft 30 to rotate, and then drive the balustrade 20 to swing around the rotating shaft. In this embodiment, the drive is a motor. In other embodiments, the driver may have other structures, which are not described herein.

The controller is mainly used for controlling the driver to drive the rotating shaft to rotate. The controller is electrically connected with the driver. That is, the driver controls the rotating shaft to perform different actions according to the instruction of the controller, so as to control the handrail to perform different swinging actions or postures.

Referring to fig. 3, preferably, the balustrade includes a plurality of spaced-apart segmented rails; and each section bar is correspondingly provided with a rotating shaft. That is, the handrail is composed of a plurality of independent sectional bars, and each sectional bar is driven by the corresponding rotating shaft. Thus, the sectional bars can do different postures or different swinging actions.

Optionally, the sectional fence includes railing posts 21 and a guardrail body 22 fixed between two adjacent railing posts 21. Guardrail body 22 is apart from the upper surface certain distance of bridge main part, and railing post 21 is fixed in the pivot. Thus, when the rotation shaft drives the railing post 21 to rotate, the guardrail body 22 moves along with the railing post 21, so that the railing can swing.

In the present embodiment, the bridge structure has an upright mode, a tip-over mode, a sway mode, and a yaw mode.

In the erect mode, the balustrade 20 is erected relative to the bridge body 10 (as shown in fig. 4). That is, the balustrade 20 stands vertically on the surface of the bridge main body 10.

In the tip-over mode, the balustrade 20 is attached to the upper surface of the bridge body 10 (as shown in fig. 5). That is, the balustrade 20 forms an angle of 0 degree or an angle of 180 degrees with the upper surface of the bridge main body 10. When the wind speed is high or the bridge vibrates, the rotating shafts corresponding to all the railings can be driven by the motor at the same time, so that the railings slowly overturn on the upper surface of the bridge main body; at the moment, the bridge is in the mode of overturning, so that the streamline degree of the bridge section can be effectively improved, the wind load borne by the bridge is reduced, and the bridge has remarkable effects of reducing the vibration amplitude of the bridge and improving the flutter critical wind speed.

In the sway mode, the balustrade 20 sways with respect to the bridge body 10 (as shown in fig. 6, the left balustrade 20 and the right balustrade 20 in fig. 6 show the balustrade 20 at different times). Unlike the upright mode and the tipping mode, the balustrade is in motion all the time, and the balustrade is in swinging motion all the time. When the wind speed is high or the bridge vibrates, the rotating shafts corresponding to all the railings can be driven by the motors at the same time, and the railings of each part control the motors to input the same vibration frequency, amplitude and phase according to the incoming wind speed or the vibration characteristics of the bridge, and the maximum vibration amplitude can reach +/-90 degrees, so that the active control of the vibration of the bridge section is realized, the vibration amplitude is effectively reduced, and the flutter critical wind speed is improved.

In the staggered mode, two sectional bars perform different swinging motions (as shown in fig. 7), in fig. 7, the

rails

20a, 20b, and 20c represent different sectional bars, and fig. 7 shows the states of the

rails

20a, 20b, and 20c at the same time. Unlike the swing mode, in the swing mode, all the balustrades move synchronously; while in the stagger mode, there is asynchronous motion in all the segmentation bars. Optionally, in the staggered swing mode, the frequency of swing of two of the segmented columns is different; or, the amplitude of the swing of two segmented columns is different; alternatively, the phase of the wobble differs for two segmented columns. When the wind speed is high or the bridge vibrates, the rotating shafts corresponding to the sectional fences can be independently controlled by the motor according to the incoming wind speed or the vibration characteristics of the bridge, and different vibration frequencies, amplitudes and phases are respectively input, so that the coherence of a wind field is disturbed, the aerodynamic force of each block of the cross section of the bridge is asynchronous, and the purposes of reducing the amplitude of a vibration structure and improving the flutter critical wind speed are achieved.

It will be appreciated that the balustrade of the present invention is not limited to the above-described forms but may be a unitary balustrade, i.e. one balustrade from the end of the bridge to the other. It will be appreciated that in the case of an integral balustrade, the bridge can only have an upright mode, a tip-over mode, and a sway mode.

In this embodiment, the balustrade is an access way balustrade. The maintenance road railing is located the outside, can quick response, effectively reduces the harm of wind-induced vibration to the bridge. It will be understood, of course, that the invention is not so limited.

Referring to fig. 8, in one embodiment, the bridge is a box girder suspension bridge, the total width of the closed box girder is 49.8m, the thickness of the closed box girder is 4.09m, and the height of the rail is 1.21 m. The segment model is utilized to carry out wind tunnel test research on flutter performance, and the test result is shown in figure 9.

As can be seen from fig. 9, the results show that the access way balustrade causes a rapid decrease in flutter critical wind speed at positive wind attack angle, and after the balustrade is removed, the flutter critical wind speed is significantly increased, which is also consistent with the overall overturn state of the balustrade of this embodiment (fig. 5). The test also shows that the guardrail of the access road has important influence on vortex-induced vibration and flutter of the bridge structure, the invention realizes the active adjustment of the posture of the guardrail and can effectively improve the pneumatic performance of the cross section of the bridge.

Referring to fig. 10, fig. 10 is a schematic cross-sectional view of a bridge structure according to another embodiment of the present invention. Unlike the previous embodiment, in the present embodiment, the bridge body is a half-open box girder structure. The structure of the semi-open box girder is also known in the art, and the detailed structure is not described herein.

Similarly, in the present embodiment, the bridge structure also has a standing mode, a tipping mode, a swinging mode, and a staggered mode.

In the erect mode, the balustrade is erected relative to the bridge body. That is, the balustrade stands vertically on the main body surface of the bridge.

Under the mode of overturning, the railing pastes the upper surface at the bridge main part. That is, the railing and the upper surface of the bridge main body form an included angle of 0 degree or an included angle of 180 degrees. When the wind speed is high or the bridge vibrates, the rotating shafts corresponding to all the railings can be driven by the motor at the same time, so that the railings slowly overturn on the upper surface of the bridge main body; at the moment, the bridge is in the mode of overturning, so that the streamline degree of the bridge section can be effectively improved, the wind load borne by the bridge is reduced, and the bridge has remarkable effects of reducing the vibration amplitude of the bridge and improving the flutter critical wind speed.

In the rocking mode, the balustrade rocks relative to the bridge body. Unlike the upright mode and the tipping mode, the balustrade is in motion all the time, and the balustrade is in swinging motion all the time. When the wind speed is high or the bridge vibrates, the rotating shafts corresponding to all the railings can be driven by the motors at the same time, and the railings of each part control the motors to input the same vibration frequency, amplitude and phase according to the incoming wind speed or the vibration characteristics of the bridge, and the maximum vibration amplitude can reach +/-90 degrees, so that the active control of the vibration of the bridge section is realized, the vibration amplitude is effectively reduced, and the flutter critical wind speed is improved.

In the staggered swing mode, there are two segmented columns that perform different swing actions. Unlike the swing mode, in the swing mode, all the balustrades move synchronously; while in the stagger mode, there is asynchronous motion in all the segmentation bars. Optionally, in the staggered swing mode, the frequency of swing of two of the segmented columns is different; or, the amplitude of the swing of two segmented columns is different; alternatively, the phase of the wobble differs for two segmented columns. When the wind speed is high or the bridge vibrates, the rotating shafts corresponding to the sectional fences can be independently controlled by the motor according to the incoming wind speed or the vibration characteristics of the bridge, and different vibration frequencies, amplitudes and phases are respectively input, so that the coherence of a wind field is disturbed, the aerodynamic force of each block of the cross section of the bridge is asynchronous, and the purposes of reducing the amplitude of a vibration structure and improving the flutter critical wind speed are achieved.

Referring to fig. 11, in one embodiment, the bridge is a half-open split double box girder cable-stayed bridge, the width of the half-open box girder is 38.5m, the thickness of the half-open box girder is 3.8m, and the height of the rail is 1.21 m.

The sectional vortex-induced vibration performance wind tunnel experimental study is carried out on the sectional vortex-induced vibration performance wind tunnel by utilizing the sectional model, and the test result is shown in figure 12. As can be seen from fig. 12, the main cause of the large-amplitude vortex-induced vibration of the access road balustrade is the access road balustrade, and in the experimental process, after the access road balustrade on the future flow side is removed, the vortex-induced vibration disappears, which is similar to that in the invention, the balustrade is turned over integrally. The two tests also show that the access road railings have important influence on vortex-induced vibration and flutter of the bridge structure, the active adjustment of the railing postures is realized, and the pneumatic performance of the bridge section can be effectively improved.

Of course, it is to be understood that the bridge girder main body structure of the present invention is not limited to the above two.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A bridge construction, comprising:

a bridge body;

the railings are positioned on the two side edges of the bridge body;

the driver is used for driving the rotating shaft to rotate;

the controller is used for controlling the driver to drive the rotating shaft to rotate; the controller is electrically connected with the driver;

the bridge structure has an upright mode, a tip-over mode, and a sway mode;

in the erect mode, the balustrade is erected relative to the bridge body; the handrail is vertically erected on the surface of the bridge main body;

in the overturning mode, the railing is attached to the upper surface of the bridge main body; the guardrail and the upper surface of the bridge main body form an included angle of 0 degree or an included angle of 180 degrees;

in the swing mode, the railing swings relative to the bridge main body;

the handrail comprises a plurality of segmented railings which are arranged at intervals; each subsection fence is correspondingly provided with one rotating shaft;

the bridge structure is also provided with a staggered swing mode;

2. The bridge structure according to claim 1, wherein in the staggered swing mode, the frequencies of the swings of two of the section bars are different;

or, the amplitude of the swing of two segmented columns is different;

alternatively, the phase of the wobble differs for two segmented columns.

3. The bridge construction of claim 1, wherein the segmented rails comprise railing posts and a railing body secured between two adjacent railing posts.

4. The bridge construction of claim 1, wherein the bridge body is a closed box girder construction.

5. The bridge construction of claim 1, wherein the bridge body is a half-open box girder construction.

6. The bridge construction of claim 1, wherein the balustrade is an access way balustrade.

7. The bridge construction of claim 1, wherein the drive is an electric motor.