JPH04366208A - Bridge of active oscillation-controlling type - Google Patents

Abstract

PURPOSE:To secure the safety of a vehicle or the like running on a bridge and a girder by controlling oscillation due to vehicle running, wind, earthquake, and the like working on the bridge of the suspension type of an obliquely stretched bridge, a suspension bridge, or the like, actively with the use of a controller. CONSTITUTION:At the lower section of suspension material 3 for connecting towers 1 and girders 2 to each other with, variable attenuation devices 4 and springs 5 are arranged in parallel with each other. By sensors 6 set on the girders 2, the oscillation of the girders 2 due to the running of a vehicle, earthquake, wind, and the like is detected. The detected oscillation of the girders 2 is analyzed by a computer, and the attenuation coefficients of the variable attenuation devices 4 are controlled. On the suspension material 3, resisting forces according to the attenuation coefficients of the variable attenuation devices 4 are generated, and the oscillation of the girders 2 is suppressed.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention applies to cable-stayed bridges, suspension bridges, and other types of bridges in which the load acting on girders and girders is suspended and supported by multiple hanging members. This invention relates to an active vibration damping type bridge equipped with a vibration damping mechanism to suppress horizontal movement caused by the above.

0002

[Prior Art] The applicant has incorporated variable stiffness elements (earthquake-resistant elements) in the form of braces, walls, etc. into the column-beam frame of a structure.
The rigidity of the variable rigidity element itself or the connection state between the frame body and the variable rigidity element is made variable, and its characteristics are analyzed by computer against vibrational external forces such as earthquakes and wind, and the rigidity of the structure is determined so that it does not resonate. Various active damping systems and variable rigidity structures have been developed to improve the safety of structures by changing the
3-114770, JP-A-63-114771, etc.)
.

[0003] In addition, various active damping systems have been proposed that take into consideration the non-resonance and damping properties of structures, using hydraulic damping devices with variable damping coefficients (for example, Japanese Patent Laid-Open Publication No. 2-209568 to 71, etc.).

Furthermore, as a vibration damping device that can be used in these active vibration damping systems, for example, Japanese Patent Application No. 2-37992 discloses
These include the cylinder lock device of No. 1, and the variable damping device for vibration damping structures of Japanese Patent Application No. 2-42078.

The basic principle of the cylinder lock device is as follows:
Hydraulic chambers are provided on both sides of both rod-shaped pistons in the cylinder body, and the pistons are fixed or movable by closing the pressure oil in the two hydraulic chambers using switching valves or by allowing them to flow.

When the cylinder lock device is used in an active damping system, a variable stiffness element is provided within the column and beam frame of the structure, and one of the column and beam frame and the variable stiffness element (or the variable stiffness elements) is Connect the cylinder bodies and connect the rod to the other. When the switching valve is fully open, the pressure oil is substantially free to move, and the damping coefficient of the cylinder lock device takes the minimum value cmin. At this time, relative movement between the column-beam frame and the variable rigidity element is also substantially free. When the switching valve is closed, there is virtually no movement of pressure oil (it does not necessarily have to be completely closed), and the damping coefficient of the cylinder lock device takes the maximum value cmax. At this time, the column-beam frame and the variable rigidity element are substantially fixed or nearly fixed. Furthermore, the variable damping device described above is capable of adjusting the opening degree of the switching valve in the cylinder lock device, and can change the damping coefficient of the device in multiple stages or steplessly.

[0007] In addition, the applicant has filed Japanese Patent Application No. 2-280712.
In this paper, we propose a high-damping structure that realizes passive vibration damping by setting the damping coefficient of a high-damping device having a high damping coefficient to a predetermined damping coefficient according to the natural vibration mode of the structure.

[0008]

[Problem to be solved by the invention] By the way, when considering suspension type bridges such as cable-stayed bridges and suspension bridges, unlike ordinary structures, they tend to undergo large displacements with long periods due to wind, earthquakes, etc. It is also necessary to take into account vertical movements caused by vehicle running, etc., and it is desirable to reduce these vibrations as much as possible for safe vehicle running. Furthermore, depending on the installation conditions, vibrational external force due to waves or the like may be applied to the tower section that supports the girder via hanging materials.

[0009] The present invention aims to provide a safe bridge with less shaking by actively controlling vibrations caused by running vehicles and disturbances such as wind, earthquakes, and waves on a suspended bridge. be.

0010

[Means for Solving the Problems] The present invention provides an actuator such as a hydraulic cylinder or a variable damping device, and a control means using a computer or the like to control these, so that the vibration of a suspended bridge can be controlled. This is what I did.

As a means of directly suppressing the vertical vibration of the girder, an actuator or a variable damping device is provided at the end or in the middle of the hanging material that supports the girder, and this actuator or variable damping device is installed at the top and bottom of the girder. control according to the movement.

[0012] The suspension member provided with the actuator or the variable damping device referred to here includes a cable that diagonally connects a tower and a girder in a cable-stayed bridge, a main cable that connects between towers or a tower and an anchor structure in a suspension bridge, Alternatively, it is a hanger that connects the main cable and girder on a suspension bridge.

Furthermore, by providing a spring means having a predetermined elasticity in parallel with the actuator or the variable damping device, the actuator or the variable damping device can function effectively in a stable connection state.

The vertical movement of the girder is detected by a plurality of sensors (for example, accelerometers, etc.) as vibration detection means installed at predetermined positions on the girder, etc.
The vibrations obtained by the sensor are analyzed by a computer, etc., and the vibrations of the bridge girder are controlled by controlling the operation (control force) of the actuator or the damping coefficient of the variable damping device. can be suppressed.

Mainly, in order to deal with horizontal vibrations of the girder caused by wind, earthquakes, etc., an actuator or variable damping device is installed between the horizontal girder components constituting the girder to generate a horizontal control force. This is actively controlled according to the horizontal vibration obtained by the vibration detection means, and the horizontal vibration of the girder is suppressed.

[0016] Also, for the tower section, an actuator or variable damping device is provided between the tower components constituting the tower frame to generate a control force for suppressing the vibration of the tower due to external disturbances, and by controlling this, the external disturbances can be suppressed. It is possible to suppress the vibration of the tower section due to

The above-mentioned vertical and horizontal vibration suppression means for the girder and vibration suppression means for the tower can be provided individually, but by using them together, an even greater vibration suppression effect can be obtained for the bridge as a whole.

Regarding a specific control method, when an actuator such as a hydraulic cylinder is used, it is sufficient to directly apply a control force in the direction of suppressing vibration.

When using a variable attenuation device, the following control method can be used, for example.

■ Put the variable damping device in a nearly free state (
A method of controlling by switching between a state (with a small damping coefficient) and a near-lock state (with a large damping coefficient) to eliminate resonance against disturbances.

[0021] ■ Like the vibration control system described in JP-A-2-240340, a large damping coefficient is applied at low vibration levels to exert as large a damping force as possible depending on the vibration level, and non-resonance is achieved at high vibration levels. Method.

■ Like the vibration control system described in Japanese Patent Application Laid-Open No. 2-209569, multiple vibration levels are assumed,
A method of controlling the damping coefficient of a variable damping device to obtain the optimum damping performance at each vibration level.

[0023] ■ Like the damping system described in JP-A-2-209568 or JP-A-2-209570, non-resonance and damping properties are judged in a composite manner, and variable damping is performed according to the characteristics of the disturbance. How to select and control the damping coefficient of a device.

(2) A method of controlling the control force by focusing on the control force provided by the variable damping device, such as the vibration damping system described in JP-A-2-209571.

[0025] The method (2) above is particularly effective against unsteady vibrations such as earthquakes, and the method (2) is similar to control using an actuator such as a hydraulic cylinder.

[0026]

[Embodiment] Next, the illustrated embodiment will be explained.

FIG. 1 is an elevational view of an active vibration damping type bridge in which the present invention is applied to a cable-stayed bridge.

In the figure, reference numeral 4 denotes a variable damping device, which is provided in parallel with the spring 5 at the bottom of the diagonally stretched hanging member 3. By interposing the variable damping device 4 in the middle of the hanging material 3, when the girder 2 vibrates due to vehicle running, earthquakes, wind, etc., the vibration is transmitted to the hanging material 3, and the variable damping device 4 is interposed in the hanging material 3. A resisting force is generated depending on the damping coefficient of the device 4. Although the spring 5 is shown as a coil spring in the figure, this does not necessarily mean that it is coil-shaped, but rather that it has a larger elastic modulus than the hanging material 3.

A vertical motion sensor 6 is installed at a predetermined position on the girder 2, and mainly detects the vertical vibration of the girder 2 due to the running of the vehicle. Although only one location is shown in the figure, multiple locations may be installed on the girder 2. The vertical movement or vertical movement and horizontal movement of the girder 2 is detected by the sensor 6, and this is analyzed by a control means such as a computer (numeral 8 in FIG. 2), and the damping coefficient of the variable damping device 4 is controlled. Suppress vibration.

FIG. 2 shows a horizontal cross section of the girder 2 position in this embodiment, in which the cross beams 2b connecting the main girders 2a and the brace-like diagonal members 2c between the cross beams 2b are connected to the variable damping device 4a. It is connected with. When the girder 2 shakes significantly due to disturbances such as earthquakes and wind, the damping coefficient of the variable damping device 4a is controlled in accordance with the horizontal motion detected by the horizontal motion sensor 7 to suppress the vibration of the girder 2.

FIG. 3 shows a vertical cross section at the position of the tower 1 in this embodiment. When the columns 1a constituting the tower 1 are connected, there is a cross member 1b, and a brace-like diagonal member 1c between the cross members 1b. are connected by a variable damping device 4b. When the tower 1 shakes significantly due to external disturbances such as earthquakes or wind, the vibrations can be adjusted according to the vibrations detected by sensors (not shown) installed at predetermined positions (upper, lower, middle, etc.) of the tower 1. The vibration of the tower 1 is suppressed by controlling the damping coefficient of the damping device 4b. Control in this case is basically the same as in the case of conventional seismic control structures, and
If the lower part of the unit is underwater, it is also affected by waves and other external vibrational forces.

In this embodiment, the variable damping devices 4, 4a, and 4b are used as vibration damping devices, but a hydraulic cylinder or the like may be used as the vibration damping device to directly apply a control force. In addition, in this embodiment, the computer 8
is installed on the girder, but it can also be installed and controlled outside the bridge.

[0033]

[Effects of the invention] ■ For suspension type bridges such as cable-stayed bridges and suspension bridges, a vibration damping device such as a variable damping device is installed at the suspension member position to prevent vibration of the girder due to vehicle running and disturbances such as wind, earthquakes, waves, etc. It is possible to actively control the vibration caused by the bridge and realize a safe bridge with less shaking due to external disturbances.

[0034] By minimizing the vibration of the bridge, the running stability of vehicles etc. can be improved and accidents can be prevented.

[Brief explanation of the drawing]

FIG. 1 is an elevational view showing an embodiment in which the present invention is applied to a cable-stayed bridge.

FIG. 2 is a horizontal sectional view of the girder position in the embodiment of FIG. 1;

FIG. 3 is a vertical sectional view of a tower section in the embodiment of FIG. 1;

[Explanation of symbols]

Claims (5)

[Claims] 1. A bridge of a type in which a plurality of hanging members suspend and support a girder and a load acting on the girder, comprising: vibration detection means for detecting vertical vibration of the girder; an actuator that is installed in the suspension member, and includes an actuator that generates a control force on the hanging material, and a control means that actively controls the control force of the actuator in accordance with the vibration of the girder obtained by the vibration detection means. This is an active vibration damping type bridge that is characterized by: 2. The active damping type bridge according to claim 2, wherein spring means having a predetermined elasticity is provided at an end or in the middle of the hanging member in parallel with the actuator. 3. A variable damping device with a variable damping coefficient is provided in place of the actuator, and the damping coefficient of the damping device is actively controlled by a control means in accordance with the vibration of the girder, and the variable damping device is installed. 3. The active damping type bridge according to claim 1, wherein the connected state of the position can be controlled. 4. In a bridge of a type in which a plurality of hanging members suspend and support a girder and a load acting on the girder, horizontal vibration of the girder is detected between horizontal girder components constituting the girder. an actuator that generates a control force for suppressing horizontal vibration of the girder due to disturbance; and a control for actively controlling the control force in response to the horizontal vibration of the girder. An active vibration damping bridge characterized by being provided with means. 5. The active damping type bridge according to claim 4, wherein a variable damping device having a variable damping coefficient is provided in place of the actuator, and the damping coefficient of the damping device is adjusted according to the horizontal vibration of the girder. is actively controlled by a control means, and the connection state between the girder components can be controlled.