JPH10183558A - Earthquake damping device for harbor structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce effect of the earthquake vibration on a harbor structure having a revetment in the rear and secure a life line during the earthquake. SOLUTION: An energy absorption damper 15 is intervened between a pile pier 1 and a revetment 5, and an access board 6 for connecting the pier 1 and the revetment 5 has one end fixed to the revetment 5 or the pier 1 by a fastening means 20. A prescribed-size space is provided between the free end of the access board 6 and the pier 1 or the revetment 5 in the other side so as to reduce an impact load and a lateral load transmitted from the revetment 5 to the pier 1 by the damper 15 in occurring an earthquake and at the same time the access board 6 is relatively moved so that the force transmitted to the pier 1 is eliminated via the access board 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a harbor structure used as a mooring berth or the like, and more particularly to a harbor structure which is constructed in the sea area in front of a revetment having a retaining wall and communicates with the revetment via a bridge board. Related to seismic device.

[0002]

2. Description of the Related Art As this kind of harbor structure, there is, for example, a straight pier as shown in FIG. This pier 1
The pier main body 3 is supported on a plurality of piles 2 cast on the sea floor, and is connected to a revetment 5 having a retaining wall 4 by a cross board 6. The retaining wall 4 of the revetment 5
Here, a block type in which a plurality of blocks 7 are stacked is used. The back side is a backing layer 8 filled with a backing material, and the front side is a rubble layer 9 on which rubble is deposited.
Each is reinforced.

[0003]

By the way, the above-mentioned handpiece 6
Is usually composed of an assembly of high-strength and high-rigidity structures, for example, a prestressed concrete girder (PC girder), the both ends of which are the uppermost block (curb block) of the pier body 3 and the retaining wall 4. It is fitted and supported by step portions 10 and 10 'formed on the wall opposed to 7a. Therefore, when a large earthquake occurs, the shaking of the revetment 5 is directly transmitted to the pier main body 3 via the pier 6 and a large impact load and a lateral load are applied to the pier 1, and the pier 1 may be damaged. is there.

[0004] However, hitherto, the impact applied to the pier body 1 when a ship berths or the main body 3 of the pier 1 during an earthquake.
Since the design load of the pier 1 is only determined in consideration of the inertia force applied to the pier 1, for example, when an earthquake of the magnitude of the Great Hanshin-Awaji Earthquake occurs, the impact load transmitted from the revetment 5 via the pier 6 And cannot withstand lateral loads,
In fact, many piers 1, especially their stakes 2, were damaged (broken or buckled) in the Great Hanshin-Awaji Earthquake, which was a major cause of delay in restoration.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to reduce as much as possible the effects of earthquake shaking on a port structure having a seawall behind it. An object of the present invention is to provide a vibration control device that greatly contributes to securing a lifeline.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a vibration control device for a harbor structure which is constructed in a sea area in front of a revetment having a retaining wall and communicates with the revetment via a crossing board. An energy absorbing damper is interposed between the earth retaining wall and the harbor structure, and the crosspiece is installed so as to be able to follow the shaking of the seawall or the harbor structure. It is characterized by.

[0007] In the vibration damping device configured as described above,
While the damper reduces the impact load and lateral load applied to the harbor structure from the revetment, the bridge plate does not stretch between the revetment and the harbor structure, and the harbor structure is It will not be damaged.

[0008] In the present invention, the structure in which the above-mentioned crossing board follows the shaking of the seawall or the harbor structure is optional. For example, one end of the crossing board is fixed to one of the retaining wall and the harbor structure. At the same time, it is possible to adopt a structure in which the other end of the transfer plate is slidably supported on one of them.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of a vibration damping device according to the present invention. The port structure targeted in the present embodiment is the straight pier described above, and the overall structure thereof and the structure of the revetment behind it are basically the same as those shown in FIG. Since there is no change, here, only the main parts are shown, and the same parts are denoted by the same reference numerals. In the present embodiment, the pier 1
Of the pier main body 3 and the curb block 7a constituting the earth retaining wall 7 of the revetment 5 are provided with step portions 11 and 1 having large steps.
2 are formed, and support frames 13 and 14 made of H-section steel are arranged in each of the steps 11 and 12. Each of the support frames 13 and 14 extends along the opposing walls of the pier 1 and the revetment 5 in the corresponding steps 11 and 12, respectively, and each anchor frame (not shown) is attached to the pier body 3 and the curb block 7a. It is fixed using.

Also, the support frame 1 on the pier 1
A plurality of dampers 15 constituting the vibration control device according to the present invention are interposed between the support 3 and the support frame 14 on the revetment 5 side. The damper 15 is formed of an oil damper here, and its cylinder portion 15a is connected to the support frame 13 on the pier 1 side, and its piston rod 15b is connected to the support frame 14 on the revetment 5 side. The boot 16 surrounds the piston rod 15b.

On the other hand, support plates 17 and 18 are fixed to the upper surfaces of the support frames 13 and 14, respectively.
The bridge 6 is bridged between 7 and 18. Here, the crossing plate 6 is made of a prestressed concrete girder (PC
A plurality of beams 19 are arranged in rows, and one end of each is fixed to the support plate 17 or 18 alternately on the fixed side using a fastening member 20 such as a bolt and nut. More specifically, every other PC digit 19
are fixed to the support plate 17 on the pier 1 side, and the pair of PC plates 19b, 19b... located between them are fixed to the support plate 18 on the revetment 5 side.
The opposite fixed side of the C-shaped beams 19a and 19b is the support plate 17 on the other side.
Or slidably mounted on 18.

Here, each PC digit 19 (19a, 19b)
Is formed to have a length shorter than the distance L between the step portions 11 and 12, and each fixed end has a corresponding step portion 11,
It is abutted slightly against the 12 vertical walls. Thus, a space 21 having a predetermined size S is formed between the non-fixed side end (free end) of each PC girder 19 (19a, 19b) and the vertical wall of the step portions 11, 12. .

In the present embodiment, when an earthquake occurs and the revetment 5 shakes, the movement is transmitted to the pier 1 via the damper 15. At this time, the vibration energy applied to the pier 1 from the revetment 5 is absorbed by the damper 15, so that not only the impact load is not applied to the pier 1 but also the swing amount (amplitude) is reduced to a fraction of the swing amount of the revetment 5. descend. At this time, each PC girder 19 (19a, 19
b) moves integrally with the fixed revetment 5 or the pier 1, but due to the presence of the space 21, each free end moves relative to the corresponding revetment 5 or the pier 1 and the corresponding step portion 11. , 12, so that the crosspiece 6 does not cause damage to the pier 1.

On the other hand, as described above, the sway amount of the pier 1 is reduced to a fraction of the sway amount of the revetment 5 by the damper 15, so that the size S of the space 21 is reduced to the maximum sway amount of the pier 1. Even if it is set smaller, each PC digit 19 (19
a, 19b) does not hit the pier 1 or the curb block 7a of the revetment 5. The fact that the size S of the empty space 21 can be reduced in this way means that it is easy to secure the traveling road surface in normal times, and for example, it can be easily dealt with by covering a small cover plate.

Incidentally, when the damper 15 does not exist, a space 21 having a size corresponding to the maximum shaking amount of the revetment 5 must be secured on the free end side of each PC girder 19 (19a, 19b). For example, like the Great Hanshin-Awaji Earthquake,
m large tremors are observed,
Must be set to be extremely large, and not only the size of the lower structure for slidably supporting the passing plate 6 becomes large, but also extremely troublesome work is required to secure the traveling road surface in normal times.

In the above embodiment, an oil damper is used as the damper 15, but the type of the damper is arbitrary, and for example, a viscous damper, a friction damper, or the like can be used. Further, in the above embodiment, the PC girder 19 constituting the pier 6 is connected to the pier 1 side and the revetment 5
Although the fixed points are alternately arranged on the side and the side, the fixed points may be unified on the pier 1 side or the revetment 5 side. Further, the type of the cross plate 6 is also arbitrary, and for example, a PC slab or a frame-structured beam or slab can be used instead of the PC beam 19. Further, in the above-described embodiment, one end of the PC girder 19 constituting the bridge plate 6 is fixed to the pier 1 or the revetment 5 by using the fastening member 20. However, the PC girder 19 does not necessarily have one end thereof. It is not necessary to fix, for example, a spring may be arranged in the space 21 on the free end side to urge the PC girder 19 to one side, and one end thereof may abut against the pier 1 or the revetment 5. Further, the type of the retaining wall 4 of the revetment 5 is also arbitrary, and a caisson type or a sheet pile type can be adopted instead of the block type in which the blocks 7 are stacked.

[0018]

As described above in detail, according to the vibration control device for an offshore structure according to the present invention, the effect of the earthquake sway transmitted from the revetment to the harbor structure via the pier is greatly reduced. Therefore, damage to the harbor structure can be prevented beforehand, which has an effect of greatly contributing to securing a lifeline in the event of a large earthquake.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a vibration control device for a harbor structure according to the present invention.

FIG. 2 is a plan view showing the structure of the vibration damping device shown in FIG. 1 with a part thereof opened.

FIG. 3 is a cross-sectional view schematically showing an overall structure of a harbor structure which is an object of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pier (harbor structure) 2 Piles 3 Pier main body 4 Retaining wall 5 Seawall 6 Crossing board 7 Block 13,14 Support frame 15 Damper 17,18 Support plate 19 PC girder

Claims (2)

[Claims] 1. A vibration control device for a harbor structure constructed in a sea area in front of a revetment having a retaining wall and communicating with the revetment via a crossing board, wherein the damping device is provided between the retaining wall and the harbor structure. An energy absorbing damper is interposed therebetween, and the crosspiece is installed so as to be able to follow the shaking of the seawall or the harbor structure. 2. An end portion of a splint is fixed to one of a retaining wall and a harbor structure, and the other end of the splint is slidably supported by one of the other. The vibration control device for a harbor structure according to claim 1, wherein: