JP2001081721A - Base isolated structure on water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable floating structure on the water by providing a cylindrical retaining wall whose upper end is projected on water surface on a water bottom, storing liquid therein, and supporting the floating structure due to the buoyancy of a floating body on the liquid. SOLUTION: A plurality of the cylindrical retaining walls 13 whose upper ends 13a are projected on the water surface 11a of a water region 11 are provided on the water bottom 12 of the water region 11 in which a bridge girder 10 is erected. A liquid 14 having high specific gravity and viscosity is stored in the cylindrical retaining wall 13. The bridge girder 10 whose both the ends 10a are supported on both banks is erected, the floating body 18 is provided on the lower end of a pier 17 projected at a position corresponding to the cylindrical retaining wall 13 of the lower face of the bridge girder 10, and floated and supported by the liquid 14. Thereby since the floating body 18 set afloat and supported has no influence due to movement and force of water due to water flow, sea level, ocean waves or the like, the floating structure can be stably installed on the water of the water region 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a floating structure such as a bridge or a deck supported on water through a floating body.

[0002]

2. Description of the Related Art As a conventional general floating structure above water, for example, as shown in FIG. 6, a floating body 3 is provided at the lower end of a pier 2 projecting from the lower surface of a bridge girder 1 and the floating body 3 is provided. The bridge girder 1 is suspended and supported on the water surface 4 by the buoyancy of the bridge girder, and both ends of the bridge girder 1 are buffered near the abutment (reaction wall) 5 erected and fixed on both banks to support the bridge girder 1 horizontally. It has been known for a long time that it is a floating bridge rotatably connected with a hinge 7 or a floating airport-like floating airport constructed by floating a huge pontoon with a flat surface on the sea. I have.

[0003] Needless to say, these floating structures above are based on the premise that the structures receive the buoyancy of water. It is required to be configured so as to be able to appropriately cope with the accompanying vertical movement, rocking due to waves, and the like.

[0004] Therefore, among the conventional floating structures above, as a method of coping with horizontal movement due to water flow, various mooring methods, position control methods using self-propelled equipment, and the like are known. As a method to cope with vertical movements caused by typical water level fluctuations and swaying due to waves, an anchor that directly connects the fixed foundation provided on the sea floor and the floating body and mechanically grasps and fixes the vertical movements caused by the tide level fluctuations In this method, the vertical movement of the floating body is not fixed, and some buffer mechanism is provided at the connecting part such as the end of the floating body and the quay, and the vertical movement of the floating body due to tide level fluctuation and the shaking due to waves (vertical A buffer system that mechanically absorbs relative displacement) is known.

[0005] Of the above-mentioned methods, specific examples of the floating bridge using the buffering method include, for example, the bridge shown in Fig. 6 or Japanese Utility Model Publication No. 55-40078 and Japanese Utility Model Publication No. 5
As in the connecting bridge disclosed in Japanese Patent Application Laid-Open No. 5-40079, a connecting bridge is erected between a pair of structures having at least one of which is a floating structure floating above water, and a liquid is provided on the surface of one of the floating structures There is known a structure in which a pool or well is provided for storing water, a float (floating body) is disposed in the pool or well, and the float and one end of a communication bridge are swingably connected.

[0006]

As described above, the conventional waterborne structure supports the structure itself or the structure in any system such as a mooring system, a position control system, an anchor system or a buffer system. It is based on the idea that a floating body is used as a means, and that the floating body is directly suspended and supported by the water in the water area where the structure is installed.
Therefore, in these methods, the floating body itself directly receives the movement and power of water such as water flow, water level fluctuation, and waves in the water area supporting the floating body, so that there is water between the floating body and the structure supported by the floating body. However, there is a need for a large-scale buffering means capable of controlling the movement of the floating body caused by the movement and the force of the floating body, and there is a problem that the equipment cost and the maintenance and management cost for this are extremely high.

For example, in the bridge shown in FIG. 6, an abutment (horizontal support) for supporting the bridge girder 1 between both ends of the bridge girder 1 supported on the water surface by the floating body 3 and the buffer girder 6 connected to both banks. Since the bridge girder 1 and the buffer girder 6 are rotatably connected to each other via the hinge 7 on the reaction wall 5, even if the bridge girder 1 and the buffer girder 6 can freely rotate according to the fluctuation of the water level, the floating body that supports the bridge girder 1 Since 3 itself is only floating in the water 4, there is a problem that it is greatly affected by the flow of water in the water area, the fluctuation of water level such as tide level, and the movement and power of water such as waves.

In Japanese Utility Model Publication No. 55-40078 and Japanese Utility Model Publication No. 55-4079, between a fixed structure such as a road bridge and a floating structure floating on the water surface, or both floating structures are floating on the water surface. Since the connecting bridge is erected between the connecting bridge and the floating structure, or between both the connecting structures and the floating structure, the connecting bridge is erected by the buffer means. Even if it is movably supported, the floating structure itself simply floats in the water of the water area where the connecting bridge is to be installed, so the flow of water in that water area, fluctuations in water level such as tide level, waves, etc. They are free to move under the movement and force of the water, and in that sense, these prior arts cannot be a basic solution to provide a stable floating structure.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional floating structure above, and has been proposed as a floating structure such as a bridge or a floating deck, which is floated and supported by a liquid through a floating body. However, it is stable, robust and economical floating without being directly affected by water movement, water level fluctuations, waves, etc. in the water area where these floating structures are installed. It is intended to provide a building structure.

According to the first aspect of the present invention, as a specific means therefor, a floating structure such as a bridge or a deck supported on a liquid via a floating body is provided. A cylindrical retaining wall whose upper end protrudes above the water surface is provided at the bottom of the water area, and a high specific gravity viscous liquid is stored in the cylindrical retaining wall and floated on the liquid in the cylindrical retaining wall. The floating structure is supported by the buoyancy of the floating body.

According to a second aspect of the present invention, in the first aspect of the present invention, the floating structure is a bridge girder having both ends supported on both sides via fulcrums, and a floating body is provided at a lower end of the pier. Is supported by a viscous liquid with a high specific gravity in the cylindrical retaining wall.

According to a third aspect of the present invention, in the first aspect of the present invention, the floating structure is a deck having a plurality of floating bodies provided on a lower surface, and the floating body provided on the lower surface of the deck is provided inside the cylindrical retaining wall. It is characterized by being supported by a viscous liquid with a high specific gravity.

According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, the high specific gravity viscous liquid stored in the cylindrical retaining wall is, for example, sodium silicate.

[0014]

In the floating structure according to the present invention, a cylindrical retaining wall having an upper end protruding above the water surface is provided at the bottom of the water in which the floating structure is installed, and a high specific gravity is provided in the cylindrical retaining wall. The viscous liquid is stored, and the floating structure provided on a part of the floating structure is floated on the liquid in the cylindrical retaining wall to support the floating structure. The floating structure can be stably installed on the water without being affected by water movement or force due to water level fluctuation due to a water flow or tide level in the water area where the water is installed.

Further, the liquid in the cylindrical retaining wall that supports the floating body has a specific gravity greater than that of water, so that the buoyancy of the floating body can be increased to reduce the volume of the floating body. It is possible to suppress an increase in the size of the whole object, and furthermore, by making this liquid viscous, it is possible to improve the vibration damping characteristics and the earthquake resistance of the floating body.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a floating structure according to the present invention will be described with reference to an embodiment shown in the drawings. FIG. 1 shows an embodiment in which a floating structure is a bridge. A plurality of cylindrical retaining walls 13 having a height whose upper end 13a protrudes above the water surface 11a of the water area 11 are provided on the water bottom 12 of the water area 11 to be erected. And the viscous liquid 14 is stored.

The cylindrical retaining wall 13 is formed of a concrete wall or steel sheet pile having an appropriate thickness.
Of the liquid 14 permeated or stored inside
Is constructed so as not to leak out to the outside, and the upper end 13a of the retaining wall is provided at the upper end 13a of the water area 11 even if the water level of the water area 11 greatly changes due to a daily tide level fluctuation or a water level fluctuation caused by water increase during a storm. The water is prevented from flowing into the inside, and the height position is set so as to be always shut off from the water in the water area 11.

On the other hand, above the water area 11 where the tubular retaining wall 13 is provided, both ends 10 a
A bridge girder 10 supported by the bridge girder is provided, and an airtight floating body 18 is provided at the lower end of a pier 17 protruding from the lower surface of the bridge girder 10 at a position corresponding to the cylindrical retaining wall 13. Numeral 18 is suspended and supported by the high specific gravity viscous liquid 14 stored in the cylindrical retaining wall 13. Although not shown, a cover made of elastic rubber or a sheet is provided between the upper end 13a of the retaining wall and the pier 17, so that water in the water area 11 outside the tubular retaining wall 13 is provided.
It is preferable to be able to prevent the inflow into the inside 3.

The liquid 14 stored in the cylindrical retaining wall 13 has a specific gravity larger than that of water so as to increase the buoyancy of the floating body 18 and reduce the volume of the floating body 18.
Further, it is desirable that the viscosity is higher than that of water so as to suppress the vibration to the floating body 18. As a liquid satisfying such conditions, sodium silicate (water glass), sodium polytungstate (SPT heavy liquid), or the like is used. But
It is preferable to use sodium silicate (water glass) in terms of cost and the like.

FIG. 4 shows an embodiment in which the floating structure is a huge deck such as a floating airport having a flat surface to be installed on the sea. On the water bottom 22, the upper end 23 a is the water surface 2 of the water area 21.
A plurality of cylindrical retaining walls 23 having a height protruding above 1a are provided, and a viscous liquid 24 having a large specific gravity is stored in each of the cylindrical retaining walls 23.

The deck 20 installed above the water area 21 in which the cylindrical retaining wall 23 is provided is formed of a huge flat plate-like structure having a flat surface, and the lower surface of the flat plate-like structure has a cylindrical shape. At the lower end of a pillar 27 protruding at a position corresponding to the retaining wall 23, an airtight floating body 28 is provided.
Numeral 8 is suspended and supported by viscous liquid 24 having a high specific gravity stored in cylindrical retaining wall 23.

Although the deck 20 shown in FIGS. 4 and 5 has a structure in which a plurality of rooms 26 are provided through a partition 25 inside, the deck 20 in this embodiment has an airtight structure provided on the lower surface. The floating body 28 having the property is floated and supported by the liquid 24 stored in the cylindrical retaining wall 23, and the deck 20 itself does not float in the water of the water area 21. As shown in 5,
It is not necessary to use an airtight pontoon provided with an internal space formed by the partition walls 25 and the plurality of rooms 26, and may be constituted by a floor slab structure made of a steel plate or concrete.

[0023]

According to the present invention, the floating bodies 18, 28 provided on the lower surface of a floating structure such as a bridge, a sea deck, etc., are replaced with the water bottoms 12, 22 of the water bodies 11, 21 in which the floating structure is installed. Are supported by the high-specific-gravity and viscous liquids 14 and 24 in the cylindrical retaining walls 13 and 23 whose height is higher than the water surface, so that the water is generated in the water bodies 11 and 21 where the floating structure is installed. The cylindrical retaining walls 13 and 23 resist, block and respond to water movement and force due to water level fluctuations due to water currents, tide levels, etc., and the liquid in the cylindrical retaining walls 13 and 23 will respond. Since the floating bodies 18 and 28 supported by the floating bodies 14 and 24 are not affected by the movement or force of the water such as the water current, the tide level fluctuation, and the waves, the floating structure is connected to the water area 1.
It can be stably installed on the water of 1,21.

By using viscous liquids 14 and 24 having a high specific gravity as the liquid in the cylindrical retaining walls 13 and 23, the buoyancy of the floating bodies 18 and 28 is increased to reduce the volume of the floating bodies, The structure can be reduced in size, and by adjusting the viscosity thereof, the floating bodies 18 and 28 can be given vibration damping characteristics and earthquake resistance.

In a case where the floating structure of the present invention is applied to a bridge, a comparison between the tubular retaining wall 13 and a conventional pier structure of this type of bridge shows that the conventional pier structure of this type of bridge has: For example, as in an abutment 5 shown in FIG. 6, a footing 8 supported by a foundation pile 9 is provided on a foundation ground at a bridge erection point, and the abutment 5 and a bridge body (bridge girder) are supported by the footing 8. While it is necessary to have a solid foundation structure, in the floating structure of the present invention, FIG.
As shown in the figure, the load acting on the wall surface and the bottom surface of the cylindrical retaining wall 13 is basically only the pressure obtained by multiplying the specific gravity of the injection liquid 14 by the depth, and the vertical load of the bridge body is applied to the cylindrical retaining wall 13. Does not act directly, so that the wall surface and the bottom surface of the retaining wall 13 only need to have a structure capable of resisting the above-mentioned pressure, and therefore, there is an advantage that a rigid foundation structure such as a conventional bridge is not required.

Further, when the behavior of the floating structure of the present invention is applied to a bridge and the seismic behavior and seismic performance are examined, the conventional floating bridge shown in FIG. As shown in FIG. 8 and FIG. 8, the abutment 5 supporting both ends of the bridge girder 1 horizontally moves in the direction of arrow A due to the earthquake, but the seismic force hardly acts on the floating body 3 floating on the water for supporting the bridge girder 1. Alternatively, it is conceivable that a phase difference occurs in the seismic force between the abutment 5 and the (pier portion) supported by the floating body 3 of the bridge girder 1, so that the bridge girder 1 undergoes horizontal bending deformation. A horizontal reaction force in the direction perpendicular to the bridge axis is generated in the portion supporting the bridge girder 1.

On the other hand, when the floating structure of the present invention is applied to a bridge, the floating body 18 supporting the bridge girders 10
9 and 10, the fulcrum 16 supporting both ends of the bridge girder 10 and the middle part of the bridge girder 10 due to the earthquake, as shown by the chain lines in FIGS. 9 and 10. Both the tubular retaining wall 13 and the tubular retaining wall 13 move substantially integrally in the direction of arrow A. As a result, the horizontal bending deformation of the bridge girder 10 and the generation of the horizontal reaction force at the fulcrum 16 in the direction perpendicular to the bridge axis are suppressed. It becomes possible.

The use of the viscous liquid 14 in the cylindrical retaining wall 13 means that a horizontal force is applied to the cylindrical retaining wall 13 at the time of an earthquake, causing the floating body 18 to sway or roll. When the impact force is generated, the liquid 14 can absorb or attenuate the vibration caused by the impact, which is advantageous in terms of seismic performance.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration when a floating structure of the present invention is applied to a bridge.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a partial cross-sectional view showing the state of action of pressure on the cylindrical retaining wall shown in FIG.

FIG. 4 is a side view showing a configuration when the floating structure of the present invention is applied to a marine deck.

FIG. 5 is a plan view of FIG. 4;

FIG. 6 is a side view showing a configuration of a conventional floating bridge.

FIG. 7 is a plan view showing behavior and seismic performance of a conventional floating bridge during an earthquake.

FIG. 8 is a side view of FIG. 7;

FIG. 9 is a plan view showing behavior and seismic performance of the floating bridge according to the present invention during an earthquake.

FIG. 10 is a side view of FIG. 9;

[Explanation of symbols]

 10: Bridge girder 11: Bridge installation water area 12: Water bottom 13: Cylindrical retaining wall 14: Liquid 15: Both banks 16: Movable fulcrum 17: Bridge pier 18: Floating body 20: Marine deck 21: Deck installation water area 22: Water bottom 23: Cylindrical Retaining wall 24: Liquid 25: Partition wall 26: Room 27: Pillar 28: Liquid

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Choro Kikukawa 1-2-22-19 Kitahorie, Nishi-ku, Osaka City Kawada Industries Co., Ltd. Osaka Branch Office (72) Inventor Shinichi Miyachi 1-2-22-19, Kitahorie, Nishi-ku, Osaka City Kawada Kogyo Co., Ltd. Osaka Branch F term (reference) 2D059 AA03 AA05 BB11 BB15 GG01 GG15

Claims (4)

[Claims] A bridge supported on the liquid via a floating body,
A floating retaining structure, such as a deck, provided with a cylindrical retaining wall whose upper end protrudes above the water surface at the bottom of the body of water where these floating structures are installed, and has a high specific gravity inside the cylindrical retaining wall. And a viscous liquid is stored, and the floating structure is supported by the floating structure of the floating body floating on the liquid in the cylindrical retaining wall. The floating structure is a bridge girder having both ends supported on both sides via fulcrums, and a floating body is provided at the lower end of the pier, and the floating body at the lower end of the pier is fixed at a high specific gravity in the cylindrical retaining wall. The vibration-isolated water-floating structure according to claim 1, which is suspended and supported by a viscous liquid. 3. The floating structure is a deck provided with a plurality of floating bodies on the lower surface, and the floating body provided on the lower surface of the deck is suspended and supported by a high specific gravity and viscous liquid in a cylindrical retaining wall. The vibration-free floating structure according to claim 1. 4. The vibration-isolated floating structure according to claim 1, wherein the viscous liquid having a high specific gravity and stored in the cylindrical retaining wall is, for example, sodium silicate.