CN101660292B - Viscous vibration-absorption auxiliary rope device for cable-stayed bridge - Google Patents

Abstract

The invention relates to a viscous vibration-absorption auxiliary rope device for a cable-stayed bridge and belongs to the technical field of wind resistance as well as vibration resistance and vibration-absorption in bridge engineering. The auxiliary rope device comprises an auxiliary rope, a hoop connected with an external sleeve of a main stay cable, an external hoop of the auxiliary rope, a connecting screw rod and a connecting screw hole piece of the hoop connected with the external sleeve of the main stay cable, a viscous damper with two ends respectively connected with the auxiliary rope and a main beam of the bridge, as well as a connecting component connected with the damper and the auxiliary rope. The auxiliary rope is connected with the main cable of the cable-stayed bridge through the hoop and the screw connecting piece so as to form a new rope net system and improve the power property and air power property of the stay cable. Simultaneously, under the condition that the auxiliary rope generates deformation, the viscous damper carries out vibration absorption energy consumption so as to further decrease the vibration of the bridge, thus being specially suitable to energy consumption vibration absorption. The material is low in cost, the construction is simple and the effect is obvious.

Description

Viscous damping auxiliary cable device for cable-stayed bridge

technical field

The invention relates to a viscous vibration damping auxiliary cable device for a cable-stayed bridge, belonging to the technical field of wind resistance, earthquake resistance and shock absorption of bridge engineering.

Background technique

A cable-stayed bridge is a structural system composed of towers under pressure, cables under tension and girders under bending. Because the spanning capacity of the cable-stayed bridge is greater than that of the girder bridge, it is widely used in bridge construction and is the most important type of long-span bridge. The cable-stayed bridge is a self-anchored system, which has the characteristics of no need for expensive ground anchors, good overall rigidity and wind resistance, plus its large spanning capacity, cantilever construction, low cost and beautiful appearance. However, as the spans of cable-stayed bridges increase, the stay cables become longer and longer. As the main load-bearing components of cable-stayed bridges, the cable-stayed cables have large flexibility, low internal damping, and wide natural frequency distribution, and are easily vibrated under the action of wind, wind and rain, and beam tower displacement at the supporting end.

The vibration mechanism of cables in cable-stayed bridges is very complicated. According to different excitation sources, the main vibration types of stay cables can be divided into two categories: one is the vibration of stay cables caused by the combined action of wind or wind and rain, and the other is vibration of stay cables caused by the displacement of beam towers at the supporting ends of stay cables. vibration. At present, passive control is the main method to suppress the vibration of the cable. The main measures include: changing the surface shape of the cable to change the dynamic characteristics of the cable; adding a passive damper at the proximal end of the cable. For the stay cables on cable-stayed bridges, viscoelastic dampers are usually used as control equipment. At present, oil dampers and high-efficiency rubber dampers are widely used at home and abroad. However, passive control of cable vibration is not the best choice for cable vibration control. Studies have shown that the control effect of passive control is related to the ratio of the distance between the damper and the cable end and the cable length. The larger the ratio, the better the control effect . Due to the limitation of the location of the stay cables, in order not to affect the beauty of the bridge, the ratio of the distance between the damper to the end of the cable and the length of the cable is limited. Thus, for longer cables, it is likely that sufficient damping cannot be provided to control the vibration of the cable, thereby rendering passive control ineffective. Therefore, it is of great engineering significance to develop a vibration damping device with low cost, various functions and good effect.

Contents of the invention

The invention proposes a viscous vibration damping auxiliary cable device for a cable-stayed bridge, which has the characteristics of low cost, obvious comprehensive vibration damping effect and the like. When the cable-stayed bridge is subjected to strong winds and earthquakes, the device can be combined with the main cable to form a cable network system, increase the damping of the cable, improve the overall dynamic performance and aerodynamic properties, effectively dissipate energy, and reduce the bridge body. vibration, thus ensuring the applicability and safety of the bridge.

In order to achieve the above object, the present invention adopts the following technical solutions. The invention comprises an auxiliary cable, a first hoop fixedly connected to the outer sleeve of each cable-stayed main cable, a second hoop fixed on the first hoop for the auxiliary cable to pass through, and a viscous damper. Among them: the auxiliary cables pass through the second hoops in series and are connected between the cable-stayed main cables, one end of which is fixed on the uppermost cable-stayed main cable, and the other end is fixed on the main on the beam. The auxiliary cable and the second hoop can slide, and there is no relative deformation between the second hoop and the outer sleeve of the cable-stayed main cable.

The diameter of the auxiliary cable is 0.2 to 0.5 times the diameter of the cable-stayed main cable, and the material is the same as that of the cable-stayed main cable, and the inner diameter of the second hoop is 1.0 to 1.2 times the diameter of the auxiliary cable.

The structure of the first hoop is as follows: two semi-circular shaped steels are fixed together by bolts, and the inner diameter of the semi-circular shaped steel is the same as the outer diameter of the outer sleeve of the cable-stayed main cable. Two second hoops are fixed symmetrically on each first hoop.

One auxiliary cable is connected in series with at least three stay cables, and the crossing angle between the auxiliary cable and the stay cables is generally 70° to 110°, and the vertical crossing efficiency of the two is appropriate.

The displacement range of the viscous damper is greater than or equal to ±3cm.

When the auxiliary cable is installed, a pre-tension force needs to be applied. In principle, it is necessary to ensure that no negative tension occurs in the auxiliary cable when the cable-stayed main cable vibrates.

Compared with the prior art, the present invention has the following advantages:

1) The present invention connects the auxiliary cables with the original part of the cable-stayed cables of the cable-stayed bridge to form a new cable-net structure system. On the one hand, the auxiliary cables reduce the effective length of the stay cables and thus increase the frequency of the stay cables. On the other hand, the cable-net system changes the dynamic and aerodynamic properties of the original bridge.

2) The auxiliary cable vibration reduction measures are especially suitable for the super-long cable system of long-span cable-stayed bridges, and are effective in suppressing parametric vibration and linear internal resonance.

3) The present invention adopts a viscous damper with excellent characteristics and auxiliary cables to form a strong damping device, which further enhances the energy dissipation performance of the inventive device, and is especially suitable for energy dissipation and shock absorption under the action of hurricanes and strong earthquakes.

4) The cost of the materials used is very low, there is no complicated structure, and the effect is obvious.

Description of drawings

Figure 1 is a three-dimensional side view of the connection relationship between the auxiliary cable and the cable-stayed main cable;

Fig. 2 Side view of viscous damper;

Figure 3 is a sectional view of the auxiliary cable section along the main cable section;

Figure 4 cross-sectional view of the auxiliary cable

Figure 5 Partial cross-sectional view of the viscous damper;

The overall side view of Fig. 6 application of the present invention on the cable-stayed bridge;

In the figure: 1. auxiliary cable, 2. first ferrule, 3. second ferrule, 4. first bolt rod, 5. first bolt hole, 6. viscous damper, 7. connecting member, 8. Cable-stayed main cable, 9. External sleeve of cable-stayed main cable, 10. Piston rod, 11. Fixed end of viscous damper, 12. Sealing baffle, 13. Liquid silicone oil, 14. Piston head with orifice , 15, the control valve, 16, the adjustment support, 17, the adjustment chamber, 18, the outer wall cylinder, 19, the main tower of the cable-stayed bridge, 20, the main girder of the cable-stayed bridge.

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, this embodiment mainly includes an auxiliary cable 1, a first ferrule 2 connected to the outer sleeve of the cable-stayed main cable, and a second ferrule fixed on the first ferrule 2 for the auxiliary cable to pass through. 3. And the viscous damper 6. Wherein: the outer sleeve is sleeved on the outside of the cable-stayed main cable, and is anchored to the ends of the cable-stayed main cable at both ends. Auxiliary cables 1 pass through the second hoops 3 and are connected in series between the cable-stayed main cables, one end of which is fixed on the uppermost cable-stayed main cable, and the other end passes through the connecting member 7 and the piston of the viscous damper. The rods are connected, and the fixed end 11 of the viscous damper is anchored to the main girder of the cable-stayed bridge, as shown in Fig. 2 and Fig. 5 . The displacement range of the viscous damper shall not be less than ±3cm, and the viscous liquid inside the viscous damper 6 may be liquid silicone oil, mineral oil and lead.

Two second hoops 3 are symmetrically fixed on each first hoop 2, as shown in Fig. 3 and Fig. 4, the first hoop 2 is arranged vertically A set of hoops 2 are arranged in parallel, so that the vertical arrangement between the auxiliary cable 1 and the cable-stayed main cable is guaranteed. In this embodiment, the first ferrule 2 is two semi-circular shaped steels, on which a connecting bolt hole 5 is arranged, and the two shaped steels are butted through the first bolt rod 4 and the first bolt hole 5, and the cable pull The outer sleeve of the main cable is tightened. At the same time, the first hoop 2 connected to the outer sleeve of the cable-stayed main cable is welded to the second outer hoop 3 of the auxiliary cable, thereby ensuring the coordinated deformation of the second hoop 2 and the auxiliary cable 1 . In this embodiment, the inner diameter of the semicircular shaped steel is the same as the outer diameter of the outer sleeve of the cable-stayed main cable.

The mechanism of the connecting member 7 is: the two ends are respectively anchored and clamped with the end of the auxiliary cable and the end of the piston rod.

In this embodiment, the diameter of the auxiliary cable is 0.35 times the diameter of the cable-stayed main cable, and the material is the same or similar to that of the cable-stayed main cable. The inner diameter of the outer hoop of the auxiliary cable is 1.1 times the diameter of the auxiliary cable.

As shown in Figure 6, one auxiliary cable is connected in series with at least three stay cables, and the crossing angle between the auxiliary cable and the stay cables is 85° to 100°.

When the auxiliary cable is installed, it should be properly tensioned. In principle, it should be ensured that there is no negative tension in the auxiliary cable when the main cable vibrates.

In this embodiment, the auxiliary cables 1 are connected to the main cables of the cable-stayed bridge through the first hoop 2 and the second hoop 3 to form a new cable network system, which improves the dynamic and aerodynamic properties of the cable-stayed cables. At the same time, the viscous damper 6 reduces vibration and consumes energy when the auxiliary cables are deformed, so as to further reduce the vibration of the bridge.

The installation method of this embodiment is as follows:

First, according to the specific installation position of the auxiliary cable 1, the length of the auxiliary cable 1, the number of hoops connected to the outer sleeve 9 of the cable-stayed main cable, the number of related connecting parts, and the performance parameters and installation of the viscous damper 6 are determined. Location. The principle is: one auxiliary cable is connected in series with at least three stay cables, and the intersection angle between the auxiliary cable 1 and the stay cable 8 is preferably the vertical intersection efficiency of the two. Secondly, according to the direction from top to bottom along the cable-stayed main tower 19, the auxiliary cable 1 is penetrated and tightened with the second hoop 3 in sequence. Afterwards, the auxiliary cable 1 is connected with the outer sleeve 9 of the cable-stayed main cable with the second hoop 2 connected to the outer sleeve of the cable-stayed main cable, the connecting bolt rod 4, and the connecting bolt hole 5. It is required to ensure that the auxiliary cable 1 is combined with the outer sleeve 9 of the main stay cable to form a cable net system to ensure the coordinated deformation of the two. After that, the end of the auxiliary cable 1 close to the main beam is connected to the piston rod 10 of the viscous damper through the connecting member 7. It is required to apply a pre-tension force to the auxiliary cable properly. In principle, it should be ensured that no negative tension occurs in the auxiliary cable when the main cable vibrates. Finally, the end of the viscous damper 6 and the main beam 20 are anchored to ensure that no relative deformation occurs between the two.

Claims (7)

1. viscous vibration lazy halyard device that is used for cable stayed bridge is characterized in that: comprise lazy halyard (1), be connected in each and tiltedly draw outer all being fixed with of first cuff (2), each first cuff (2) on the main rope outer sleeve to be used for second cuff (3) and the viscous damper (6) that lazy halyard passes; Wherein: lazy halyard (1) passes second cuff (3) and is serially connected in each and tiltedly draws between the main rope, and an end of lazy halyard (1) is fixed on uppermost one and tiltedly draws on the main rope, and the other end is fixed on the cable-stayed bridge main-beam by viscous damper (6).

2. a kind of viscous vibration lazy halyard device that is used for cable stayed bridge according to claim 1 is characterized in that: all be symmetrically fixed with two second cuffs (3) on each first cuff (2).

3. according to claim 1 or the described a kind of viscous vibration lazy halyard device that is used for cable stayed bridge of claim 2, it is characterized in that: the diameter of described lazy halyard (1) is for tiltedly drawing 0.2 to 0.5 times of main rope diameter, material with tiltedly draw main rope identical, the internal diameter of described second cuff (3) is 1.0 to 1.2 times of lazy halyard (1) diameter.

4. according to claim 1 or the described a kind of viscous vibration lazy halyard device that is used for cable stayed bridge of claim 2, it is characterized in that: described first cuff (2) is fixedly formed by the bolt part by two ring-like shaped steel of semicircle, and the internal diameter of the ring-like shaped steel of semicircle is identical with the external diameter that tiltedly draws the main rope outer sleeve.

5. according to claim 1 or the described a kind of viscous vibration lazy halyard device that is used for cable stayed bridge of claim 2, it is characterized in that: a lazy halyard (1) links to each other with three skew cables serial connection at least, and lazy halyard (1) is 70 degree～110 degree with the suspension cable intersecting angle.

6. according to claim 1 or the described a kind of viscous vibration lazy halyard device that is used for cable stayed bridge of claim 2, it is characterized in that: the displacement range of described viscous damper (6) is more than or equal to ± 3cm.

7. according to claim 1 or the described a kind of viscous vibration lazy halyard device that is used for cable stayed bridge of claim 2, it is characterized in that: described lazy halyard (1) need apply pretension when installing, and does not occur negative pulling force in the time of will guaranteeing tiltedly to draw the main rope vibration in principle in the lazy halyard.

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