CN104775362B - Wind-induced vibration suppression structure of bridge tower structure with blunt body section - Google Patents

Abstract

The invention discloses a kind of bluff body cross section bridge tower wind-induced vibration and suppress structure, relate to science of bridge building technology, this is configured to right angle, side two, bluff body cross section is excised, and making bridge tower cross section is the section form with right angle corner cut；And this right angle corner cut arranges continuously along bridge tower；Right angle corner cut be about 1/16～1/17 for bridge tower cross section length, right angle corner cut wide is about 1/8～1/9 that bridge tower cross section is wide.The present invention changes the air Characteristics of Flow Around of bridge tower, significantly improves the galloping stability of bluff body cross section bridge tower, simple in construction, easy construction and good economy performance.

Description

Wind-induced vibration suppression structure of bridge tower structure with blunt body section

technical field

The invention relates to the technical field of bridge engineering, in particular to a wind-induced vibration suppression structure involving blunt tower columns.

Background technique

For the pylon structure of long-span bridges, when the section form is blunt, the structure is soft, the mass is light, and the damping is low, galloping problems will easily occur under the action of natural wind. Galloping vibration is one of the four main forms of wind-induced vibration of bridges. Galloping is a divergent self-excited vibration, and galloping mainly occurs on slender and flexible structures (such as bridge towers), and is a large vibration in the cross-wind direction due to the self-excitation of airflow. Because the galloping vibration is emissive and has a great destructive effect, once it occurs, it will cause disastrous consequences.

The right-angle blunt body section bridge tower has the advantages of beautiful appearance, light structure, and convenient construction, and has been used in practical bridges. However, the critical wind speed of galloping vibration of this kind of bridge tower is low, and there are serious galloping safety problems. .

Contents of the invention

In view of this, the object of the present invention is to provide a wind-induced vibration suppression structure of a blunt tower column, which can effectively improve the galloping critical wind speed of the bridge tower.

The technical solution adopted by the present invention to solve its technical problems is as follows:

A wind-induced vibration suppression structure of a bridge tower structure with a blunt body section. Right-angle cut angles are arranged at the two top corners on one side of the bridge tower facade, and the cut angles are arranged continuously along the height direction of the bridge tower, and its length is the height of the bridge tower; The cut corners are symmetrically arranged on the front and rear sides of the bridge tower.

As preferably, the cross-section of the right-angle cut angle is a square, its length is 1/16 to 1/17 of the long section of the bridge tower, and its width is about 1/8 to 1/9 of the width of the bridge tower section; the length The direction is parallel to the central axis of the bridge deck.

The beneficial effect of the present invention is that the galloping critical wind speed of the blunt section bridge tower can be significantly improved, the galloping force coefficient value of the bridge tower in the galloping unstable wind direction angle range can be increased, and the galloping safety of the bridge tower can be effectively improved , thereby improving the safety of the bridge structure; the structure is simple and easy to construct.

Description of drawings

Fig. 1 is the elevation view of the pylon of a certain long-span cable-stayed bridge in China in the embodiment of the present invention;

Fig. 2 is the side view of Fig. 1;

Fig. 3 is the sectional schematic diagram of A-A section among Fig. 2;

Figure 4 is a partial enlarged view of the cut corner of the bridge tower section.

Figure 5 is a comparison curve of the root mean square value of the wind-induced vibration displacement of the transverse bridge direction with the change of wind speed for the bridge tower with and without the cut angle under uniform flow at each wind direction angle;

Figure 6 is a comparison curve of the root mean square value of the wind-induced vibration displacement along the bridge direction with the change of wind speed under the uniform flow and different wind direction angles of the bridge tower with cut angle;

Figure 7 is a comparison curve of the root mean square value of the wind-induced vibration displacement in the transverse bridge direction with the change of wind speed in the uniform flow of the bridge tower with cut angles at various wind direction angles;

Figure 8 is a comparison curve of the root mean square value of the wind-induced vibration displacement along the bridge direction with the change of wind speed for a bridge tower with a cut angle in turbulent flow and various wind direction angles;

Figure 9 is a comparison curve of the root mean square value of the wind-induced vibration displacement of the bridge tower with a cut angle in the turbulent flow and the cross-bridge direction at various wind direction angles with the wind speed;

Note: The horizontal deflection angles of the incoming flow are β=0°～180°, with an interval of 15°, rotated counterclockwise, zero degrees means along the bridge direction (the direction along the bridge is the direction along the span of the bridge, and the direction across the bridge is the direction along the bridge vertical direction), the auxiliary tower blows air in the direction of the windward side.

detailed description

The present invention will be further described below in conjunction with drawings and embodiments.

Referring to Fig. 1, Fig. 2 and Fig. 3, the wind-induced vibration suppression structure of the pylon with blunt body section includes two cut angles in the form of right angles. hexahedron.

Fig. 4 is a preferred implementation manner, the cut corner is a 500mm×500mm right angle.

Taking the main bridge tower of a certain bridge under construction as an example, the wind-induced vibration test of the aeroelastic model will compare the situation of adding the rear bridge tower of the present invention and the wind-induced vibration of the bridge tower without any engineering measures. The aeroelastic model of the whole tower was made according to the geometric scale ratio of 1:80, and the wind-induced vibration test of the aeroelastic model was carried out in the wind tunnel. The aeroelastic model meets the consistency conditions of geometric parameters, elastic parameters, inertia parameters and gravity parameters in the design, so the static and dynamic behavior of the model structure can be guaranteed to be consistent with the prototype bridge tower. Because the bridge tower section is a typical blunt body, the viscous parameter condition does not obviously affect the similarity of the flow around it, so the similarity condition of the viscous parameter is relaxed; and a smaller damping is used to obtain a more significant wind vibration phenomenon .

Figure 6 shows the comparison of the root mean square value of the wind-induced vibration displacement in the transverse bridge direction with the wind speed of the bridge tower with and without the chamfer angle under uniform flow when the wind angle is 0° and the wind angle is 180° The wind speed and displacement in the figure have been converted to the actual bridge tower through the similarity criterion. It can be seen that the root mean square value of the bridge tower displacement increases from 50mm to about 600mm when the wind speed is 55m/s at a wind angle of 180° without any engineering measures, and when the wind speed continues to increase, the bridge tower The vibrations are very violent all the time. When the wind speed is 70m/s, the root mean square value of the displacement is the largest, reaching 750mm. This amplitude is already very large, and it can be considered that the bridge tower has obvious galloping phenomenon. Therefore, the galloping stability of the blunt bridge tower without any engineering measures is poor, and there are serious galloping safety problems.

In order to effectively suppress the wind-induced vibration of the bridge tower with blunt body section and improve the galloping stability of the bridge tower. The wind vibration suppression structure of the present invention is added to the upper tower column part of the bridge tower. The test results found that the root mean square value of the displacement of the bridge tower with the cut angle was set at the wind angle of 0° and the wind angle of 180° was small, and the galloping phenomenon of the bridge tower did not occur.

In order to further analyze the suppression effect of the present invention on the galloping vibration of the blunt body cross-section bridge tower, the test takes 15 ° angle as the change step size, and the bridge tower model is carried out in the range of 0 ° ~ 180 ° wind deflection angle, and the incoming flow is a uniform flow. When the wind tunnel test (as shown in Figure 6 ~ 7). The test results show that the root mean square value of the displacement of the tower top of the bridge tower is small in each range of wind deflection angle, and no galloping phenomenon is found. At the same time, the root mean square value of the displacement of the tower top of the bridge tower under various wind angles when the incoming flow is turbulent is compared and analyzed (as shown in Figures 8-9). The test results show that when the incoming flow is turbulent, the root mean square value of the displacement of the bridge tower top at each wind angle is small, and no galloping phenomenon is found.

In a word, the aeroelastic test of the whole tower proves that the structure of the present invention can effectively restrain the wind-induced vibration of the bridge tower with blunt body section, and improve the galloping safety of the bridge tower.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (3)

1. a blunt body cross-section bridge tower structure wind-induced vibration suppression structure is characterized in that, the two corners of the bridge tower facade unilateral are provided with right-angle cut angles, and the cut angles are arranged continuously along the bridge tower height direction, and its length is The height of the bridge tower; two right-angle cut angles are symmetrically arranged on the front and rear sides of the bridge tower. 2. The wind-induced vibration suppression structure of blunt body cross-section bridge tower structure according to claim 1, characterized in that, the length of the cross-section of the right-angle cut angle is 1/16～1/17 of the length of the bridge tower cross-section, and the width is about It is 1/8 to 1/9 of the cross-sectional width of the bridge tower; the length direction is parallel to the central axis of the bridge deck. 3. The wind-induced vibration suppression structure of blunt body cross-section bridge tower structure according to claim 2, characterized in that, the cross-section of the right-angle cut angle is a square.