JP4320051B2 - Damping device and cable-stayed bridge provided with the device - Google Patents

Description

  The present invention relates to a spring-type tuned mass damper corresponding to a long-period vertical vibration, that is, a vibration damping device, which is compact and can easily change the damping amount corresponding to a change in natural frequency. The present invention relates to a vibration device and a cable-stayed bridge with a great vibration control effect.

A pendulum type is often used as a vibration control device for long-period vibration. This is because in the case of the pendulum type, the vibration period can be determined only by the arm length of the pendulum. However, the arm length corresponding to the vibration of about several seconds is as large as 6 m or more, and there is a mechanism called a multistage pendulum for space saving.
Japan Steel Structure Association (edition) "Wind-resistant engineering of structures" pages 342-343 Tokyo Denki University Press 1997

  The bridge under construction is in a state that is structurally unstable as compared to the completed system, and because the structural damping is small, it is likely to cause vertical vibration due to vortex excitation or the like. In the case of cable-stayed bridges, the girders being installed are cantilevered, so the vertical vibration at the end of the girders is large, and the vibration properties are generally long-period, and at each construction stage The property changes.

  A gravity pendulum type damping device with a weight suspended is supported as a damping device that synchronizes with long-period vibration, but this gravity pendulum type damping device is determined only by the arm length of the pendulum. It is based on the principle.

  However, in the case of this gravity pendulum type, since the weight of the pendulum tries to return to a stable position by gravity, that is, the gravity restoring force is used, the weight cannot be vibrated in the vertical direction.

  Therefore, in the gravity pendulum type damping device, a method for suppressing the vertical displacement component is unavoidable by suppressing the horizontal displacement component that is generated along with the vertical displacement of the bridge girder. However, in this method, the vibration damping efficiency is much worse than the method of directly suppressing the vertical displacement component.

  Also, when dealing with long-period vibrations of about several seconds, the arm length of the pendulum is 6 m or more, so the vibration control device itself becomes a huge thing corresponding to the height of a 3 to 4 story building There is a point.

  Furthermore, in the case of a structure that easily swings in the vertical direction, such as a bridge girder during construction, and the natural frequency changes at each construction step, the work corresponding to the changing natural frequency is important. There are problems that require complicated work such as changing the arm length of the pendulum accompanying changing the vertical position of the weight and installing a spring.

  On the other hand, in the spring type vibration damping device, although there is no direction restriction unlike the gravity pendulum type vibration damping device, the spring constant required for the weight weight required for vibration damping is small when it corresponds to long period vibration. Therefore, there is a problem that it is not practical as a spring that can vertically support the weight.

  In consideration of the above points, the present invention efficiently responds to vertical vibrations of a long period by vertical movement of the weight, and is more compact, responds to changes in frequency, and easily changes attenuation. An object of the present invention is to provide a cable-stayed bridge having a great vibration damping effect.

  In order to achieve the above object, a vibration damping device according to the present invention includes a first layer strut standing on a base, and a substantially horizontal first layer arm rotatably supported by the first layer strut. And a spring and attenuator provided between the first layer arm and the base, a second layer strut standing on the base, and a substantially horizontal direction rotatably supported by the second layer strut Acting on the second layer arm, one end of the first layer arm, a first connecting body connected to one end of the second layer arm, and the other end of the second layer arm. A distance between a first support point where the first layer arm is supported by the first layer support and a spring connection point where the spring is connected to the first layer arm. The distance between the first support point and the first layer connection point where the first connection body is connected to the first layer arm is large. The distance between the second support point at which the second layer arm is supported by the second layer support and the second layer connection point at which the first connection body is connected to the second layer arm, The distance between the second support point and the action point at which the weight acts on the second layer arm is large, and the weight has one end of the second layer arm and the first coupling body. It acts on the one end part of the said arm for 1st layers via (Claim 1).

Further, the spring can be moved along the first layer arm (claim 2).
Further, the attenuator is made movable along the first layer arm (claim 3).
In addition, the support for the first layer is movable along the arm for the first layer (claim 4).
Then, the support for the second layer passes through the arm for the first layer, or the arm for the first layer passes through the support for the second layer (Claim 5).

  Two first-layer struts and two first-layer arms are positioned in parallel, one end of each of the first-layer arms is connected by a first-layer connecting rod, and the second-layer arm is Parallel to both first layer arms and between the first layer arms, one end of the first connecting body is connected to the first layer connecting rod, and the other end is the second layer. (6).

  Two struts for the second layer and two arms for the second layer are located in parallel, one end of the arm for the second layer is connected by a connecting rod for the second layer, and the arm for the first layer is Parallel to the second layer arm and positioned between the second layer arms, one end of the first connector is connected to the first layer arm, and the other end is the second layer connecting rod. (Claim 7).

  It is comprised from the support | pillar for multiple layers, and the arm for multiple layers (Claim 8).

The cable-stayed bridge according to the present invention is the one in which the above-described vibration damping device is installed at the end of the bridge girder being built (Claim 9).
Further, the vibration damping device described in each of the above is installed on a bridge girder tip erection crane being erected (Claim 10).

Since the vibration damping device of the present invention is configured as described above, the following effects can be obtained.
A substantially horizontal first layer arm is rotatably supported by the first layer strut standing on the base, and a spring and an attenuator are provided between the first layer arm and the base. A substantially horizontal second layer arm is rotatably supported by the formed second layer support column, and a first connector is connected to one end of the first layer arm and one end of the second layer arm. A weight acts on the other end of the second layer arm, a first support point where the first layer arm is supported by the first layer support, and a spring in which the spring is connected to the first layer arm. The distance between the first support point and the first layer connection point where the first connection body is connected to the first layer arm is larger than the distance from the connection point, and the second layer arm is the second layer. The second support point and the weight of the second support point supported by the support column and the second layer connection point at which the first connection body is connected to the second layer arm Is a large distance from the point of action acting on the second layer arm, and the weight acts on one end of the second layer arm and one end of the first layer arm via the first connector. ,
The action point of the weight of the second layer arm and the second layer connection point are in a positional relationship in which the lever acts, and further, the first layer connection point and the spring connection point are interposed via the first connection body. Because of the positional relationship of lever action, the action point of the weight acts on the spring connection point via the lever action of the two layers, and the change in the spring length with respect to the movement amplitude of the weight can be reduced, and the spring constant Therefore, the vertical movement of the weight with a long period can be performed, and the entire apparatus can be made compact (claim 1).

  Further, since the spring is movable along with the first layer arm, it is possible to easily cope with a change in the natural frequency by changing the installation position of the spring (claim 2).

  Furthermore, since the attenuator is movable along with the first layer arm, the attenuation amount of the vibration damping device can be easily changed by changing the position of the attenuator.

  In addition, since the first layer struts can move along with the first layer arm, it can be efficiently used for structures such as bridges where the natural frequency changes at each construction stage or structures with different natural frequencies. In addition, the movement of the first support point of the first layer arm of the first layer support can be performed by placing a jack or the like between the base and the first layer arm. Can be easily lifted and moved (claim 4).

  The second layer struts penetrate the first layer arm, or the first layer arm penetrates the second layer strut, so that the first layer arm and the second layer The arm for the second layer can be positioned on the same vertical plane, that is, directly above the arm for the first layer, the arm for the first layer, the arm for the first layer, and the arm for the second layer The number of struts and second layer arms can be the same. If the arms are visible in the left-right direction, the depth of the device can be reduced. If the arms are visible in the front-rear direction, the width of the device can be reduced, making the device more compact. (Claim 5).

  Next, two first-layer struts and two first-layer arms are positioned in parallel, and one end portions of both first-layer arms are connected by a first-layer connecting rod. Is positioned parallel to both first layer arms and between both first layer arms, one end of the first connector is connected to the first layer connecting rod, and the other end is the second layer arm. When one arm for the second layer can be positioned between the arms for the first layer above the two arms for the first layer. Since the lower arm is two and the upper arm is one, the entire apparatus can be configured stably (claim 6).

  In addition, two second layer struts and two second layer arms are positioned in parallel with each other, one end of the second layer arm is connected by a second layer connecting rod, and the first layer arm is both Located parallel to the second layer arm and between the second layer arms, one end of the first connector is connected to the first layer arm and the other end is connected to the second layer connecting rod. Therefore, the weight acting on the end of the second layer arm can be attached to the two second layer arms, and the weight is attached and supported at two places. It can be mounted stably (claim 7).

  Furthermore, the spring constant of the spring can be increased by configuring it with a multi-layer strut and a multi-layer arm of four or more layers, not limited to two or three layers. It can correspond to use (claim 8).

  The cable-stayed bridge of the present invention is provided with the vibration damping device installed at the tip of the bridge girder being installed, so that it can cope with long-period vibration, and the natural frequency changes at each installation stage. It is possible to easily and efficiently cope with cases (claim 9).

  In addition, it is desirable that the vibration damping device is installed on a bridge girder erection crane that is being constructed, and the vibration damping device can be moved more easily at each erection stage (claim 10).

(Form 1)
The best mode 1 for implementing the vibration damping device of the present invention will be described with reference to FIGS.
Reference numeral 1 denotes a horizontal base for the first layer made of H-shaped steel, and two bases 1 are arranged in parallel in the front-rear position. Reference numeral 2 denotes a plurality of bolt insertion through holes formed through the upper flange of the base 1, which are formed at equal intervals. Reference numeral 3 denotes a first layer support made of a square steel pipe, 4a denotes a lower substrate fixed to the lower end of the support 3, and bolts are inserted into the insertion holes formed at the four corners of the lower substrate 4a and the through holes 2 of the base 1. The support column 3 is erected on the base 1 by fastening the nut. Reference numeral 4b denotes an upper substrate provided on the upper end of the support column 3 via a rotation mechanism K.

  Reference numeral 5 denotes an arm for the first layer made of H-shaped steel in the horizontal direction on the left and right, and is positioned above the base 1. A plurality of bolts formed on the upper flange of the base 1 are inserted into the lower flange of the arm 5. A through hole having the same interval as the through hole 2 is formed. Bolts are inserted into the through holes of the arm 5 and through holes formed at the four corners of the upper substrate 4b of the support column 3, and the first nut is fastened by tightening the nut. A first layer arm 5 is rotatably supported on the upper end of the layer support 3.

  Reference numeral 6 denotes a spring provided between the arm 5 and the base 1 on the left side of the support column 3, and reference numerals 7a and 7b denote a lower substrate and an upper substrate respectively provided at the lower end and the upper end of the spring 6 via a rotation mechanism K. As in the case of the two substrates 4a and 4b, insertion holes are formed at the four corners of the two substrates 7a and 7b of the spring 6, and bolts are inserted into the insertion holes, the through holes 2 of the base 1 and the through holes of the arm 5, and the nuts. The lower end and the upper end of the spring 6 are fixed to the base 1 and the arm 5 by the fastening.

  8 is an attenuator provided between the arm 5 and the base 1 on the right side of the support column 3, and 9a and 9b are a lower substrate and an upper substrate respectively provided at the lower end and upper end of the attenuator 8 via a rotation mechanism K. Yes, as in the case of the support column 3, insertion holes are formed at the four corners of the both substrates 9 a and 9 b of the attenuator 8. Bolts are inserted into the base 1 and the lower end and upper end of the attenuator 8 are fixed to the base 1 and the arm 5 by fastening the nut.

  The first layer support 3, the first layer arm 5, the spring 6 and the attenuator 8 are respectively provided on both bases 1 arranged in the front-rear position, and both bases 1 are provided upright on the support 3. The places are firmly connected by the first base connecting body 10 in the front-rear direction made of H-shaped steel.

  Reference numeral 11 denotes a first layer connecting rod made of H-shaped steel, which connects one end of both first layer arms 5, that is, the right end.

  Reference numeral 12 denotes an H-shaped steel base for the second layer in the horizontal direction before and after, a front end and a rear end connected to the two first layer bases 1a, a central portion 12a, and a rear end of the first base on the front side. The front portion 12b is connected to the layer base 1 and the rear portion 12c is connected to the rear-side first layer base 1 at the front end.

  Reference numeral 13 denotes a second layer strut made of a square steel pipe, which is erected on the second layer base 11, that is, the central portion 11 a, the front portion 11 b, and the rear portion 11 c, and has an upper end connected to the rotating mechanism K.

  Reference numeral 14 denotes a second layer arm made of H-shaped steel in the horizontal direction in the horizontal direction. The lower flange of the arm 14 is connected to the rotation mechanism K at the upper end of the second layer support 13, and the arm 14 is connected to the upper end of the support 13. Is supported above the first layer arm 5, and the central second layer arm 14 is positioned between the first layer arms 5.

  Reference numeral 15 denotes a second layer connecting rod made of H-shaped steel, which connects one end of the three second layer arms 14, that is, the right end.

  Reference numeral 16 denotes a first connecting body. The upper and lower portions of the central connecting piece are connected to the upper support shaft and the lower support shaft, and have a double rotation mechanism. The lower end of the first connection body 16 is for the first layer. It is connected to the connecting rod 11 (in FIG. 3, the first layer arm 5 to which the connecting rod 11 is connected), and the upper end is connected to the second layer connecting rod 15.

  Reference numeral 17 denotes a weight made of laminated steel plates, which is mounted across the other end portions, that is, the left end portions of the three second layer arms 14. R is a reinforcing rib, where the bases 1 and 12 and the arms 5 and 14 are subjected to a strong force, that is, the columns 3 and 13, the spring 6, the attenuator 8, the connecting body 16, and the weight 17 are connected. In the position.

  Then, the distance l1 between the first support point S1 where the first layer arm 5 is supported by the first layer support 3 and the spring connection point B where the spring 6 is connected to the first layer arm 5 is The distance L1 between the one fulcrum S1 and the first layer connection point T1 where the first connecting body 16 is connected to the first layer arm 5 is large, and the second layer arm 14 is connected to the second layer support 13. For the distance l2 between the supported second support point S2 and the second layer connection point T2 where the first connecting body 16 is connected to the second layer arm 14, the second support point S2 and the weight 17 are The distance L2 from the action point G acting on the second layer arm 14 is large, and the weight 17 is connected to the first layer arm 5 via one end of the second layer arm 14 and the first connecting body 16. It acts on one end of the.

  Accordingly, the weight 17 and the spring 6 are in a positional relationship in which the lever 6 acts as a lever, and a spring having a strong spring constant even if the weight 17 is large with respect to a natural frequency having a long period and a small frequency. 6 can be used, and the amount of displacement of the spring 6 with respect to the motion amplitude of the weight 17 can be reduced.

  Further, a plurality of bolt insertion through holes 2 formed in the first layer base 1 and the first layer arm 5, a lower substrate 4 a, an upper substrate 4 b, and a lower substrate of the first layer support 3. 7a, the upper substrate 7b, the lower substrate 9a of the attenuator 8, and the insertion holes formed in the upper substrate 9b, respectively, the first layer support 3, the spring 6, and the attenuator 8 are connected to the first layer arm 5 and the first layer. It moves along with the base 1 for layers, can easily cope with structures having different natural frequencies, and can easily change the amount of attenuation.

(Cable stayed bridge)
Next, one form of a cable-stayed bridge provided with the vibration damping device of form 1 will be described with reference to FIG.
In this figure, 18 is a bridge tower, 19 is a bridge girder, 20 is a cable that is stretched between the bridge tower 18 and the bridge girder 19, 21 is an erection crane installed at the tip of the bridge girder 19, and 22 is erection It is the vibration damping device of the form 1 provided in the truss frame of the crane 21, and is provided at the distal end portion of the bridge girder 19 having a large vibration damping effect.

  The vibration specifications of the cable-stayed bridge are grasped by vibration analysis, and the parameters of the damping device are determined based on the analysis.

  The weight 17 of the damping device 22 is about 1% of the vibration weight at the stage where the vibration weight is the largest in the construction step of the cable-stayed bridge, and when the span length is long, the weight weight is several tens of tf. Become.

  The spring 6 is used in both directions of compression and tension, and the strength of the spring 6 is controlled at the installation position closest to the first support point S1 where the first layer arm 5 is supported by the first layer support 3. The vibration device 22 is designed so that it can be tuned to the minimum frequency in the application erection step.

  The attenuator 8 is designed such that a certain reference setting position is determined and a required damping effect can be obtained at the lowest frequency in the application erection step of the vibration damping device 22.

  The frequency is adjusted by changing the position of the spring 6. Further, if the change in the frequency of the spring 6 alone cannot cope with the required change in the frequency, the first support point S1 of the first layer support 3 is moved along the first layer arm 5 to adjust the frequency. .

  When adjusting the effectiveness of the attenuator 8, that is, the amount of attenuation of the damping device 22, the installation position of the attenuator 8 is changed and adjusted.

  In the damping device 22 in the form of a cable-stayed bridge, when a trial calculation was made with a certain cable-stayed bridge, the vibration frequency was 0.178 to 0.326 Hz (period: 5.61 to 3.07 sec) only by changing the position of the spring 6. The vibration frequency of the bridge girder 19 that fluctuates at the time of erection is found to be 0.18 to 0.28 Hz by vibration analysis. The result is that the vibration control can be performed at the optimum tuning frequency.

  FIG. 6 shows the vibration control effect of optimum tuning in this embodiment, which is reduced to about 1/10 in some cases compared to the case without the vibration control device 22.

(Form 2)
Next, Embodiment 2 of the vibration damping device of the present invention will be described with reference to FIGS. In the following drawings, the same reference numerals as those in FIGS. 1 to 3 denote the same or corresponding elements.
In this form 2, the second layer strut 13 penetrates the first layer arm 5, and the second layer strut 13 is erected on the same first layer base 1 as the first layer strut 3. The first layer arm 5 made of H-shaped steel is divided at the portion where the second layer struts 13 are erected, and the grooved steel 5a is fixed before and after the division, and the second layer struts are fixed. A through hole 5b through which 13 penetrates is formed.

  In this case, the first layer support column 3 and the second layer support column 13 are erected on the same first layer base 1, and the first layer arm 5 and the second layer arm 14 are on the same vertical plane, That is, the second layer arm 14 is positioned directly above the first layer arm 5, and the first layer column 3 and the second layer column 13, and the first layer arm 5 and the second layer arm 14. When the arms 5 and 14 are visible in the left-right direction, the depth of the apparatus can be further reduced and the apparatus can be made compact.

  The figure shows a pair of one each of the first layer and the second layer. However, a plurality of pairs of the illustrated devices are arranged side by side, and one end of the plurality of first layer arms 5 is arranged. Are connected by a first layer connecting rod 11, one end of a plurality of second layer arms 14 is connected by a second layer connecting rod 15, and both connecting rods 11, 15 are connected by a first connector 16. In addition, the weight 17 can be mounted across the second layer arms 14.

(Form 3)
A third embodiment of the vibration damping device of the present invention will be described with reference to FIGS. In this form 3, the first layer arm 5 penetrates through the second layer support 13, and as in the form 2, the first layer support 3 and the second layer support 13 are the first layer base 1. The second-layer strut 13 made of a square steel pipe is divided at a portion where the first-layer arm 5 is located, and before and after the division, the U-shaped square steel 13a is fixed to the first layer. A through-hole 13b through which the layer arm 5 passes is formed.

  Also in this case, the first layer support column 3 and the second layer support column 13 are erected on the same first layer base 1, and the first layer arm 5 and the second layer arm 14 are the same as in the second embodiment. The second layer arm 14 is positioned on the vertical plane, that is, directly above the first layer arm 5, and the first layer column 3, the second layer column 13, the first layer arm 5, The number of the two-layer arms 14 can be made the same, the depth of the apparatus can be made smaller and more compact, and a plurality of pairs can be arranged side by side in the same manner as described above.

(Form 4)
Embodiment 4 of the vibration damping device of the present invention will be described with reference to FIGS. In this form 4, the arm has three layers, and two first-layer bases 1 in the left-right direction are arranged in parallel to the front-rear position, and the first is provided upright on both bases 1 respectively. The first layer arm 5 in the left-right direction is rotatably supported by the layer support 3, and one end portion (the right end portion in FIG. 13) of both arms 5 is connected by the first layer connecting rod 11.

  A second layer base 12 is provided in the front-rear direction on the right side inside the first layer base 1, and second layer struts 13 are erected on the front and rear portions of the base 12. 13, a second layer arm 14 in the left-right direction is rotatably supported, and one end portion (right end portion in FIG. 13) of both arms 14 is connected by a second layer first connecting rod 23a. The connecting rod 11 and the first connecting rod 23a for the second layer are connected by the first connecting body 16, and the other end portions (the left end portion in FIG. 13) of both arms 14 are connected by the second connecting rod 23b for the second layer. Has been.

  The portions where the first layer support columns 3 of both the first layer bases 1 are erected are connected by the first base connecting member 10 in the front-rear direction, and the center of the first base connecting member 10 and the second layer base 12 is connected. The parts are connected by a second base connecting body 24 in the left-right direction, and a third layer support column 25 is erected on the left side of the second base connecting body 24.

  A third layer arm 26 in a substantially horizontal direction is supported on the upper end of the third layer support column 25 via a rotation mechanism K so as to be rotatable in the left and right directions. One end (left end) of the third layer arm 26 and the second layer The second connecting rod for layer 23 b is connected by a second connecting body 27 having the same shape as the first connecting body 16, and the weight 17 is attached to the other end (right end) of the third layer arm 26. .

  Then, a second support point S2 where the second layer arm 14 is supported by the second layer support 13 and a second layer connection point T2 where the first connecting body 16 is connected to the second layer arm 14. The distance between the second support point S2 and the second coupling body coupling point T3 where the second coupling body 27 is coupled to the second layer arm 14 is large with respect to the distance.

The distance between the third support point S3 where the third layer arm 26 is supported by the third layer support column 25 and the third layer connection point T4 where the second connection body 27 is connected to the third layer arm 26. In contrast,
The distance between the third support point S3 and the action point G of the weight 17 located at the other end of the third layer arm 26 is large.

  The weight 17 passes through the end of the third layer arm 26, the second connecting body 27, the other end of the second layer arm 14, one end of the second layer arm 14, and the first connecting body 16. It acts on one end of the first layer arm 5.

  Accordingly, the lever action of the three layers makes it possible to use the spring 6 having a strong spring constant for the natural frequency having a long period and a small natural frequency even if the weight 17 is heavy. The amount of displacement of the spring 6 with respect to the movement amplitude of the weight 17 can be reduced, and the three layers have a mountain-shaped configuration, so that the structure can be made more stable.

(Other forms)
Although not shown in the drawings, as another form, two first-layer struts 3 and two first-layer arms 5 are arranged in parallel, and one end of both first-layer arms 5 is for the first layer. The second layer arm 14 is arranged in parallel with both the first layer arms 5 and between the first layer arms 5, and one end of the first connector 16 is connected to the first layer. The other end may be connected to the second layer arm 12 by connecting to the connecting rod 11. In this case, a stable state is obtained in the two-layer configuration.

In addition, two second layer struts 13 and two second layer arms 14 are arranged in parallel, and one end of the second layer arm 14 is connected by a second layer connecting rod 15 to form a first layer. The arm 5 is disposed parallel to the second layer arms 14 and between the second layer arms 14, one end of the first connecting body 16 is connected to the first layer arm 5, and the other end. May be connected to the connecting rod 15 for the second layer. In this case, the weight 17 is attached to the two second layer arms 14, and the weight 17 can be safely attached.
The above description has been given for the two layers and the three layers. However, the present invention can be applied to four layers or more, and the present invention can be constituted by a multi-layer support and a multi-layer arm.

  Further, the spring 6 may be connected to the first layer arm 5 on the same side as the first connector 16 with respect to the first layer support 3, and the columns 3, 13, and 25 are square steel pipes, Round steel pipes or H-shaped steels may be used, and the bases 1 and 12 and the arms 5, 14, and 26 can also apply square steel pipes, and the struts and arms are not limited to the above forms.

It is a front view of Embodiment 1 of the vibration damping device of the present invention. It is a top view of FIG. It is a partial removal right view of FIG. It is a top view of the base for 1st layers of FIG. It is a front view of one form of a cable-stayed bridge of the present invention. It is a figure which shows the damping effect of FIG. It is a front view of form 2 of the vibration damping device of the present invention. FIG. 8 is a plan view of FIG. 7. It is a top view of the arm for 1st layers of FIG. It is a front view of form 3 of the vibration damping device of the present invention. It is a top view of FIG. It is a cutting | disconnection right view of FIG. It is a front view of form 4 of the vibration damping device of the present invention. FIG. 14 is a plan view of FIG. 13. FIG. 14 is a partially removed right side view of FIG. 13.

Explanation of symbols

3 First layer strut 5 First layer arm 6 Spring 8 Attenuator 11 First layer connecting rod 13 Second layer strut 14 Second layer arm 15 Second layer connecting rod 16 First connector 17 Heavy Weight 19 Bridge girder 21 Construction crane 23 Second layer connecting rod 25 Third layer strut 26 Third layer arm 27 Second connected body

Claims (10)

A first layer strut standing on the base;
A substantially horizontal first layer arm rotatably supported by the first layer support;
A spring and a damper provided between the first layer arm and the base;
A second layer strut standing on the base;
A substantially horizontal second layer arm rotatably supported by the second layer support;
One end of the first layer arm, and a first connector connected to one end of the second layer arm;
A weight acting on the other end of the second layer arm,
The distance between the first support point where the first layer arm is supported by the first layer support and the spring connection point where the spring is connected to the first layer arm,
The distance between the first support point and the first layer connection point where the first connection body is connected to the first layer arm is large.
The distance between the second support point where the second layer arm is supported by the second layer support and the second layer connection point where the first connection body is connected to the second layer arm,
The distance between the second support point and the action point at which the weight acts on the arm for the second layer is large,
The vibration control device, wherein the weight acts on one end of the second layer arm and one end of the first layer arm via the first connecting body.   2. The vibration damping device according to claim 1, wherein the spring is movable along the first layer arm.   3. The vibration damping device according to claim 1, wherein the attenuator is movable along the first layer arm.   4. The vibration damping device according to claim 1, wherein the first layer support is movable along with the first layer arm.   5. The vibration damping device according to claim 1, wherein the second layer strut penetrates the first layer arm, or the first layer arm penetrates the second layer strut. Two struts for the first layer and two arms for the first layer are positioned in parallel with each other,
One ends of the first layer arms are connected by a first layer connecting rod,
A second layer arm is positioned parallel to the first layer arm and between the first layer arm;
5. The control according to claim 1, wherein one end of the first connecting body is connected to the first layer connecting rod, and the other end is connected to the second layer arm. Shaker. Two struts for the second layer and two arms for the second layer are positioned in parallel with each other,
One end of the second layer arm is connected by a second layer connecting rod,
The first layer arm is parallel to the second layer arms and between the second layer arms;
5. The vibration damping device according to claim 1, wherein one end of the first connecting body is connected to the first layer arm and the other end is connected to the second layer connecting rod. apparatus.   8. The vibration damping device according to claim 1, wherein the vibration damping device comprises a multi-layer support and a multi-layer arm.   A cable-stayed bridge comprising the vibration damping device according to claim 1, 2, 3, 4, 5, 6, 7, or 8 installed at a leading end of a bridge girder being installed.   A cable-stayed bridge comprising the vibration damping device according to claim 1, 2, 3, 4, 5, 6, 7, or 8 installed in a crane installed at a bridge girder tip construction.

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