JP3168269U - Bridge - Google Patents

Abstract

A crossover is provided that facilitates recovery after a dropped bridge. By installing an airbag device on the bridge, it is easy to recover at low cost early by floating on the sea surface without sinking to the seabed. The upper structure 33 is a main part of the bridge, and includes, for example, a main girder 11, a horizontal girder, and a floor slab 12. Most of the main girder 11, the horizontal girder, and the floor slab 12 are formed by, for example, FRP. For example, one end of the upper structure 33 is supported in a fixed state with respect to the land 4 by a fixed bearing 6 (however, rotation around a horizontal axis is allowed), and the other end is supported by a movable bearing 5 including, for example, a roller or the like. Is supported in a movable state (can be translated in a horizontal plane and can be rotated about a horizontal axis). [Selection] Figure 2

Description

  The present invention relates to a technique for a bridge that does not sink into water even if it falls from a floating body (pontoon) or the like.

  Currently, most of the bridges that span the pontoon and land are made of steel or concrete. Non-Patent Document 1 discloses an FRP pedestrian bridge for the purpose of improving durability due to salt damage.

  In Tobashi, the land part is generally a fixed bearing and the pontoon side is a movable bearing. However, because the pontoon side is not fixed, it may fall down due to natural disasters such as typhoons and sink into the sea. The current situation is to pull up or replace the dropped bridge.

  By the way, regarding an offshore structure in which an airbag device is installed, for example, Patent Document 1 discloses that a ship body is equipped with an airbag device and the airbag is operated when the boat collides with a jetty or the like. A technique for reducing the impact on the human body is disclosed.

JP-A-11-301586 (Claim 1, FIG. 1)

(Japan Society of Civil Engineers, "FRP Bridge", first edition, Japan, Japan Society of Civil Engineers, January 20, 2004, p. 177-191)

  However, when a bridge made of steel or concrete falls into the sea and sinks, it is very difficult to pull up from the sea because the weight of the bridge is heavy, and when lifting, use a salvage ship or heavy equipment It becomes. Even if it is temporarily pulled up, rusting of the steel material is likely to proceed, so that a heavy rust prevention treatment of the steel material is required. If it is not raised, it will be replaced. Both of these costs are expensive, and it takes a long time to re-use, which hinders marine traffic.

  Moreover, although the FRP footbridge is installed in the nonpatent literature 1, since the specific gravity of FRP exceeds 1, if it falls, it will sink in the sea. For this reason, FRP with strong corrosion resistance does not require rust prevention treatment after pulling up, but resistance such as water is also generated in the pulling work, and heavy machinery is required.

  Furthermore, although it has been proposed to install an airbag on a ship as in Patent Document 1 to prevent damage to the hull or the like, it is not intended to prevent settlement.

  An object of the present invention is to provide a bridge that can be easily restored after it has been dropped.

  The crossover bridge of the present invention has an upper structure that spans a floating body and another structure, and an airbag device installed in the upper structure.

  Preferably, the airbag device includes a bag case that is disposed on a lower surface or a side surface of the upper structure and stores a contracted airbag.

  Preferably, the airbag device includes a gas supply device that is disposed on a lower surface or a side surface of the upper structure and supplies gas to the airbag.

  Preferably, the airbag device includes a support that supports the upper structure or an operating device that is installed in the upper structure and starts inflation of the airbag when a falling bridge occurs.

  Preferably, the superstructure has at least one of a beam and a floor slab formed by FRP.

  According to the bridge of the present invention, even if it falls and falls on the sea, it does not sink to the seabed. Since it does not sink, it is easy to recover and the recovery cost is low.

Side view of a bridge over which a pontoon and an airbag device are installed Side view of the bridge over which the airbag device is installed Cross-sectional view of the crossover where the airbag device is installed Side view of the bridge with the airbag device activated Cross-sectional view of the bridge with the airbag device activated

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the aspect as described in drawing.

  FIG. 1 is a side view on which a bridge 1 having a pontoon 3 and an airbag device 31 is installed. FIGS. 2 and 3 are a side view and a cross-sectional view over which the bridge 1 where the airbag device 31 is installed is built. FIG. 4 and FIG. 5 are a side view and a cross-sectional view of the bridge 1 in a state where the airbag device 31 is activated after falling down.

  The bridge 1 includes an upper structure 33 that spans the pontoon 3 and the land 4, and an airbag device 31 that is installed in the upper structure 33.

  The upper structure 33 is a main body portion of the bridge 1, and includes, for example, a main beam 11, a cross beam 14, and a floor slab 12. Most of the main beam 11, the cross beam 14, and the floor slab 12 are formed by, for example, FRP. For example, one end of the upper structure 33 is supported in a fixed state with respect to the land 4 by a fixed support 6 (however, rotation around a horizontal axis is allowed), and the other end is supported by a movable support 5 including, for example, a roller or the like. Is supported in a movable state (can be translated in a horizontal plane and can be rotated about a horizontal axis).

  The airbag device 31 includes an airbag 21 (FIGS. 4 and 5), a bag case 20 (FIG. 3) that houses the airbag 21 in a contracted state, and a drive device 2 that inflates the airbag 21. Yes.

  The airbag 21 is for floating the bridge 1 (upper structure 33) dropped into a water area (sea, lake, river, etc.) by buoyancy, and floats the bridge 1 when filled with gas (for example, air). Produce possible buoyancy.

  Since the end of the upper structure 33 on the land 4 side is fixed to the land 4 by the fixed support 6, a part of the load on the bridge 1 is supported by the fixed support 6 when the bridge is dropped. It is expected. Therefore, the buoyancy generated by the airbag 21 does not necessarily have to be large enough to float the entire bridge 1.

  The airbag 21 is fixed to the side surface or the lower surface of the bridge with bolts, an adhesive, or the like. The fixing strength is such that the dropped upper structure 33 is not separated from the buoyant airbag 21 to sink into the water, the load of the upper structure 33, the position of the airbag 21 attached to the upper structure 33, and the like. It may be set appropriately according to.

  The bag case 20 is formed so as to be pushed open by the inflation of the airbag 21 and is fixed to a side surface or a lower surface of the bridge with a bolt or an adhesive.

  The drive device 2 is fixed with bolts, an adhesive, or the like at several locations on the side surface or the lower surface of the bridge 1, for example. In addition, although the drive device 2 and the bag case 20 are installed separately in the drawing, they may be installed at the same place.

  Since the end of the upper structure 33 on the land 4 side is fixed to the land 4 by the fixed support 6, when the bridge is dropped, the upper structure 33 tilts and falls from the pontoon 3 side to the sea surface. Therefore, the bag case 20 and the driving device 2 may be installed on the entire surface of the upper structure 33, but it is preferable that the bag case 20 and the drive device 2 are installed on the movable support 5 side from the center of the upper structure 33.

  As shown in FIGS. 2 and 3, the drive device 2 includes a gas supply device 22 and an operation sensor 23 (operation device).

  The operation sensor 23 is for detecting a falling bridge of the bridge 1. The operation sensor 23 is provided, for example, in the superstructure 33 or the support 5, detects the displacement of the bridge 1 with respect to the pontoon 3, and determines that the bridge has been dropped when the displacement exceeds a predetermined value. Alternatively, the actuation sensor 23 is configured by an acceleration sensor, and determines that the bridge has fallen when the acceleration exceeds a predetermined value.

  The gas supply device 22 has an air cylinder (not shown) filled with a gas such as compressed air having a required pressure. This air cylinder is connected to the airbag 21 through an air tube. Further, the gas supply device 22 has a valve (not shown) that is opened when the air cylinder is closed to maintain the filling state and a signal corresponding to the detection of the falling bridge is input by the operation sensor 23.

  In the impact relaxation airbag, gas is instantaneously supplied to the airbag, and thereafter, the airbag contracts (gas is discharged) as the impact is absorbed. On the other hand, in the airbag apparatus 31 of this embodiment, the gas supply apparatus 22 does not necessarily need to supply gas instantly. Moreover, the airbag 21 is formed in an airtight manner and maintains an inflated state. A check valve may be provided between the gas supply device 22 and the airbag 21 to prevent the backflow (discharge) of gas from the airbag 21.

  Next, the operation of the airbag device 31 of the present embodiment having the above configuration will be described.

  At the time of a typhoon, the movable support 5 on the pontoon 3 moves more than the normal fluctuation distance due to strong winds and high waves, and the operation sensor 23 connected to the movable support 5 reacts at the same time when the bridge 1 is dropped from the pontoon 3 and the gas supply device 22 reacts. Compressed gas is injected into the airbag 21 from above, and the airbag 21 is inflated. The airbag 21 covers the side surface or the lower surface of the bridge, for example, as shown in FIGS.

  Even if the crossover 1 whose side surface or lower surface is covered with the air bag 21 is dropped on the sea, the air bag 21 into which the air is inserted shows an effect as a floating ring, and prevents the crossover 1 from sinking. As a result, early recovery is facilitated at low cost.

  Further, the airbag device 31 is usually installed hidden behind the sea side surface, and the load on the system is small, so it is not noticeable to the human eye and is excellent in aesthetics.

  Furthermore, if the main members (the main girder 11, the cross girder 14, and the floor slab 12) of the bridge 1 are formed of FRP, corrosion can be suppressed and the life of the bridge 1 can be extended, and the weight is light. Therefore, the airbag 21 can be small.

  The present invention is not limited to the above-described embodiment, and may be implemented in various aspects.

  The bridge is not limited to the purpose of being bridged between the floating body and the land, and may be bridged between the floating bodies.

  The airbag, the bag case, and the like may be disposed on the upper surface side of the superstructure.

  The gas supply device is not limited to one that supplies gas to the airbag from a cylinder filled with compressed gas, but may be one that generates gas by a chemical reaction and supplies the gas to the airbag.

  The actuating device is not limited to the one having a sensor, and the airbag device may be mechanically actuated, for example, by transmitting the relative movement between the pontoon and the bridge to the cylinder valve to open the valve.

1: Crossover 2: Drive device 3: Pontoon 4: Land 5: Movable bearing 6: Fixed bearing 7: Watahashi flap 11: Main girder 12: Floor slab 13: Railing 14: Cross girder 20: Bag case 21: Air bag 22: Gas supply device 23: Actuation sensor 31: Air bag device 33: Superstructure AA: Sea surface position

Claims (5)

The superstructure spanning the floating body and other structures;
An airbag device installed in the superstructure;
Having a bridge. The bridge according to claim 1, wherein the airbag device includes a bag case that is disposed on a lower surface or a side surface of the upper structure and that stores a contracted airbag. The bridge according to claim 1, wherein the airbag device includes a gas supply device that is disposed on a lower surface or a side surface of the upper structure and supplies gas to the airbag. 4. The air bag device according to claim 1, wherein the air bag device includes a support that supports the upper structure or an operating device that is installed in the upper structure and starts inflation of the air bag in response to the occurrence of a falling bridge. No bridge. The crossover according to any one of claims 1 to 4, wherein the upper structure includes at least one of a girder and a floor slab formed by FRP.

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